SCHOOL OF MATERIALS AND MINERAL RESOURCES ENGINEERING UNIVERSITI SAINS MALAYSIA
MINERAL COMPOSITION AND PHASE ANALYSIS OF MALAYSIAN TIN ORE
By
SYED MOHAMAD ISMAIL BIN SYED MOHD SUKRI Supervisor: Dr. Suhaina Binti Ismail
Co-Supervisor: Assoc. Prof. Dr. Hashim Bin Hussin
Dissertation submitted in partial fulfillment
of the requirements for the degree of Bachelor of Engineering with Honours (Mineral Resources Engineering)
Universiti Sains Malaysia
JUNE 2017
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DECLARATION
I hereby declare that I have conducted, completed the research work and written the dissertation entitled “Mineral Composition and Phase Analysis of Malaysian Tin Ore”. I also declare that it has not been previously submitted for the award of any degree or diploma or other similar title of this for any other examining body or university.
Name of student: Syed Mohammad Ismail Bin Syed Mohd Sukri Signature : Date : 23 JUNE 2017
Witness by
Supervisor : Dr Suhaina Binti Ismail Signature : Date : 23JUNE 2017
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ACKNOWLEDGMENTS
Alhamdulillah to thank to Allah for giving me a good physically and mentally to complete this dissertation in time. Even the dissertation is only a requirement to fulfill my bachelor degree but all of the knowledge and experience are very useful and meaningful.
First of all, I would like to take this opportunity to thanks to my supervisor, Dr.
Suhaina Binti Ismail, she also the one who is lend me his hand by sharing and his knowledge, experience and personal guidance during my project. She always gives her support, teach me, and gives great advice so that I be able to focus on final year project (FYP). Sincere thanks for his continuous supporting and had been helpful throughout the duration of my project. And a big appreciation to Rahman Hydraulic Tin Sdn. Bhd. for give me the sample to do the study and indirectly implement this dissertation.
Besides, a special acknowledgement to the School of Materials and Mineral Resources (SMMRE), University Science Malaysia for providing a good and health environment and excellent facilities for final year student to run the experiment. I also want to thanks to the people here who already help me a lot during my final year project, to all the staff and technicians especially En Mokhtar, En Hasnor, En Kemuridan, En Junaidi and En Zaini whom had helped me by sharing their experience and giving the related information during lab work.
Last but not least, a special thanks to my parents Syed Mohd Sukri and Norizan Binti Omar, my family and friends forgiving me the support needed to finish up my final year project. They are always be my side whenever I felt stressed and tired during all this time. They were one of the best gift that I have until now. Thank you so much.
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TABLE OF CONTENT
Contents Page
DECLARATION II
ACKNOWLEDGMENTS III
TABLE OF CONTENT IV
LIST OF TABLES VII
LIST OF FIGURES VIII
LIST OF ABREVIATIONS XI
LIST OF EQUATIONS XII
SYMBOLS XIII
ABSTRAK XIV
ABSTRACT XV
CHAPTER 1 : INTRODUCTION 1
1.2 Objectives 4
1.3 Problem statement 4
1.4 Scope of Study 5
1.5 Thesis Organization 5
CHAPTER 2: LITERATURE REVIEW 7
2.1 Introduction 7
2.2 Mineral Identification 7
2.2.1 Mineral Identities 7
2.2.2 Mineral and Their Classification 8
2.2.3 Mineral grain size distribution 8
2.2.4 Characterization of Ore Minerals. 8
2.2.5 Physical Properties of Minerals 9
2.3 Geology of Tin 11
2.3.1 Tin 11
2.3.2 Physical Properties of Tin. 11
2.3.3 Mineralization of Tin Ore in Malaysia 12
2.3.4 Tin Ore Deposits in the World 13
2.4 Occurrences in Nature 16
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2.5 Site Project Background 16
2.5.1 Rahman Hydraulic Tin Sdn. Bhd.(RHT) 16
CHAPTER 3: METHODOLOGY 20
3.1 Introduction 20
3.2 Raw Materials 22
3.3 Crushing 23
3.3.1 Cone Crusher 23
3.4 Laboratory Sampling 24
3.4.1 Cone and Quartering 24
3.4.2 Jones Riffle Splitting 25
3.4.3 Sieving 26
3.5 Mineral Identification using Optical Microscope 27
3.6 Loss On Ignition (LOI) 28
3.7 Design of Experiment (DOE) 29
3.8 Preparation of Polish Specimens 30
3.8.1 Specimen preparation and mounting 30
3.8.2 Grinding on the flat surface 31
3.8.3 Polishing on flat surface 31
3.9 Characterization of Tin Ore 31
3.9.1 Particle Size Distribution (PSD) 31
3.9.2 Composition by using X-Ray Fluorescence (XRF) 32 3.9.3 Identification and Quantification Phase Analysis by X-Ray Diffraction 32
3.9.4 Scanning Electron Microscopy (SEM) 33
3.9.5 Liberation Studies by Image J Software (Imaging Process) 34
CHAPTER 4: RESULT AND DISCUSSION 35
4.1. Introduction 35
4.2. Sieve Size Analysis 36
4.3. Loss On Ignition (LOI) Analysis 38
4.4. Statistical Analysis 39
4.4.1. Fractional factorial design. 39
4.5. Morphology Study 46
4.5.1. Polarizing Microscope 46
4.6. Mineral composition (XRF) 52
4.5.1. Particle Size Distribution (PSD) by using Planetary Ball Mill 57
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4.7. X-Ray Diffraction (XRD) Analysis 59
4.8. SEM and EDX Investigations 62
4.9. Mineral Liberation Study (Image J). 72
CHAPTER 5: CONCLUSION AND RECOMMENDATION 76
5.1. Conclusion 76
5.2. Recommendation 78
REFERENCES 79
APPENDICES 82
APPENDIX A 82
APPENDIX B 86
APPENDIX C 87
APPENDIX D 90
APPENDIX E 92
APPENDIX F 95
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LIST OF TABLES
Page
Table 2.1: Tin in brief (The International Tin Council, 1974). 10 Table 2.4: Production of tin-in- concentrates 2010-2011 (Malaysian Smelting
Corporation Berhad (MSC), Annual Report 2011) 19
Table 3.1: Design table of Design of Experiment (DOE). 30 Table 4.1: Summary sieve size analysis at D10, D50, and D90. 36 Table 4.2: Particle Size Distribution of tin ore samples 37 Table 4.3: The result of loss on ignition of tin ore sample. 38
Table 4.4: Result of the full factorial design. 40
Table 4.5: Analysis of Variance for SMD (coded units) 40 Table 4.6: Estimated Effects and Coefficients for SMD (coded units) 41 Table 4.7: XRF analysis result of average element in sample A and sample B. 53 Table 4.8: Characteristic sizes (d10, d50 and d90) of the tin ore sample. 58 Table 4.9: Data quantitatively of sample A and B by image J 73 Table 4.10: Data quantitatively of sample C and D by image J 74 Table 4.11: Data quantitatively of sample E and F by image J. 74 Table 4.12: Data quantitatively of sample G and H by image J. 75
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LIST OF FIGURES
Page Figure 1.1: Tin-bearing areas of Southeast Asia (Taylor, 1979) 1 Figure 1.2: Map of Gunung Paku tin deposits (Ariffin, 2009) 3 Figure 2.1: Map of mineralization tin in world (Lehmann, 1990). 14 Figure 2.2: Map of tectonostratigraphic terranes of Southeast Asia. (Schwartz, 1995). 15 Figure 2.3: the location maps of Gunung Paku tin deposits (Ariffin, 2009). 18 Figure 3.1: A flowchart representing the overall experimental work. 21 Figure 3.2: Area of site sampling at Rahman Hydraulic Tin Mine 22
Figure 3.3: The samples from Rahman Hydraulic Mine. 23
Figure 3.5: Coning and quartering method of feed materials. 25
Figure 3.6: Jones Riffle Sampler 26
Figure 3.7: Endecotts EFL2000 vibrating sieve shaker 28
Figure 4.1: The graph of particle size distribution curve of tin ore sample. 37 Figure 4.2: Main effects plot for SMD in time (coded) 42 Figure 4.3: Main effects plot for SMD on speed rate (coded) 43 Figure 4.4: Figure pareto chart of the standardized effect. 44 Figure 4.5(a): Contour plot of SMD vs speed rate and time. 44
Figure 4.6: Residual Plots of SMD. 45
Figure 4.7: Photomicrograph of sulphide minerals seen in polished section. 48 Figure 4.8: (a) Pyrite (Py) and magnetite (Mg) with numerous small blebs of quartz (Qz) at 5X magnification. (b) Pyrite (Py) light in colour, Ilmenite (Il) with light colour and magnetite (Mg) polysynthetic twinning. Slightly darker colour than chalcopyrite. 49 Figure 4.9: Magnetite (Mg) slightly light colour compared to Quartz (Qz), cassiterite
(Sn) light yellow like gold with 5X magnification 50
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Figure 4.10: (a) Magnetite (Mg) greyish black with metallic lustre and irregular fracture, cassiterite (Sn) light yellow and fine grained in a quartz (Qz). (b) The pale brass yellow is pyrite (Py) with rounded arsenopyrite (Aspy). (c) Pyrite with tabular
light yellow crystal cubes in a quartz 51
Figure 4.11: Element Composition of Sample A 54
Figure 4.12: Elemental Composition of Sample B 55
Figure 4.13: Average elemental composition of sample A and sample B. 56 Figure 4.14: the cumulative PSD after T13, T22-2, T22, T43, T11, T22-3 and T41
passes through the planetary ball mill. 58
Figure 4.15: Xrd analysis data sample of tin ores 60
Figure 4.16 (a): SEM image of tin ore sample from size 4.75 mm. 62
Figure 4.16(b): EDX diffractogram of sample 4.75 mm. 63
Figure 4.17 (a): SEM image of tin ore from size 2.36 mm. 63 Figure 4.17 (b): EDX diffractogram of sample 2.36 mm. 64 Figure 4.18: (a) and (b) SEM images of tin ore from size 600 µm, (c) and (d) EDX
diffractograms of sample 600µm. 65
Figure 4.19 (a): SEM image of 425 µm 66
Figure 4.19 (b): EDX diffractogram of sample 425 µm. 66
Figure 4.20 (a): SEM image of sample from size 212 µm. 67
Figure 4.20(b): EDX diffractogram of sample 212 µm. 67
Figure 4.21 (a): SEM image of sample from size 90 µm. 68
Figure 4.21(b): EDX diffractogram of sample 90 µm 68
Figure 4.22 (a): SEM image of sample from size 75 µm. 69
Figure 4.22(b): EDX diffractogram of sample 75 µm. 69
Figure 4.23 (a): SEM image of sample from size -75 µm. 70
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Figure 4.23(b): EDX diffractogram of sample 75 µm. 71
Figure 4.24: (a) and (b) the sample A and B of size 4.75 mm and 2.36 mm. 72 Figure 4.25: (a) and (b) the sample C and D of size 600 µm and 425 µm. 73 Figure 4.26: (a) and (b) the sample E and F of size 212 µm and 150 µm. 74 Figure 4.27: (a) and (b) the sample G and H of size 75 µm and -75 µm. 75
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LIST OF ABREVIATIONS
Al Aluminium
Sn Cassiterite
SnO2 Tin Oxide Fe2O3 Iron Oxide Al2O3 Aluminium oxide
Sb Antimony
Fe Iron
XRF X- ray fluorescence XRD X- ray diffraction LOI Loss on ignition
SEM Scanning electron microscope PSA Particle size Analysis
EDX Energy-dispersive X-ray spectroscopy DOE Design of Experiment
SMD Sauter Mean Diameter
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LIST OF EQUATIONS Equation 3.1 LOI% = 𝑊₂−𝑊₃
𝑊₂−𝑊₁× 100
Equation 4.1 Y (SMD%)= 3.3509 + 0.0036X1 – 0.0024X2 Equation 4.2 Y (SMD%)= 3.3509 + 0.0036(time) – 0.0024 (speed rate)
xiii SYMBOLS g Gram
µ Micron mm milimetre
% Percent
°C Degree Celcius 2D Two Dimension 3D Three Dimension Wt% Weight percentage
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KOMPOSISI MINERAL DAN FASA ANALISIS BIJIH TIMAH MALAYSIA ABSTRAK
Dalam kajian ini, "Kandungan Mineral dan Fasa Analisis bijih timah Malaysia"
telah dijalankan dalam kajian ini menggunakan bijih timah dari Rahman Hydraulic Tin Sdn. Bhd. Kajian ini telah dijalankan dengan ciri-ciri bijih di mana fizikal, kimia, dan mineralogi lebih mendalam. Lima kaedah telah digunakan dalam projek ini, termasuk mengenalpasti mineral yang menggunakan analisis dari polaris mikroskop, komposisi mineral dengan menggunakan X-Ray pendarfluor (XRF), pengenalpastian dan analisis fasa kuantifikasi oleh X-Ray Diffraction (XRD), Imbasan Elektron mikroskop digabungkan dengan tenaga serakan X-Ray (SEM-EDX) analisis dan pemecahan mineral oleh perisian Image J. Hasil XRF menunjukkan kehadiran agregat mineral yang berbeza dan komposisi kimia seperti SnO2, Al2O3, SiO2, PO2, SO3, K2O, Fe2O3, As2O3, MgO, Na2O, TiO2, P2O5, CaO dan lain-lain sampel yang merupakan mineral terikat antara mineral lain yang terbukti dalam analisis SEM-EDX dimana Cassiterite mineral terikat bersama dengan beberapa mineral pirit, rutil, kuarza, bijih besi, dan lain-lain corak fasa XRD menunjukkan mineral lain seperti kasiterit, kuarza, bijih besi, ilmenit, stibnit dan pirotit. Kajian pembebasan Imej j adalah zarah dalam imej mentah dipisahkan dengan proses mudah yang dipanggil "nilai ambang". Objektif utama proses ini adalah untuk mengukur dan mengira kawasan imej sampel yang tidak hancur dan terbebas dari setiap sampel berdasarkan saiz sampel. Ia boleh mengkur nilai statitstik pixel dan ruang sampel.
Analisis varians (ANOVA) dengan menggunakan perisian Minitab 16 adalah untuk mengira Diameter Sauter Mean (SMD). Oleh itu, ia jelas menunjukkan bahawa ada satu kesan yang ketara, iaitu pada kadar kelajuan 0.020 dan masa pengilangan proses, sebaliknya apabila nilai P adalah lebih tinggi daripada 0.05, nilai tersebut tidak menunjukan jawapan yang terbaik.
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MINERAL COMPOSITION AND PHASE ANALYSIS OF MALAYSIAN TIN ORE
ABSTRACT
In this study, “Mineral Composition and Phase Analysis of Malaysian Tin Ore”
has been carried out in this study using tin ore from Rahman Hydraulic Tin Sdn. Bhd.
The study has been carried out with ore characterization where the physical, chemical, and mineralogical will be focused. Five method were used in this determination, which is include the mineral identification using Polarizing Microscope analysis, mineral composition by using X-Ray fluorescence (XRF), identification and quantification phase analysis by X-Ray Diffraction (XRD), Scanning Electron Microscope combined with Energy Dispersive X-Ray (SEM-EDX) analysis and mineral liberation by Image J software. The XRF result showed the presence of different aggregates of minerals and chemical composition that are SnO2, Al2O3, SiO2, PO2, SO3, K2O, Fe2O3, As2O3, MgO, Na2O, TiO2, P2O5, CaO and etc. The sample is an interlock mineral which proved in SEM- EDX result which is cassiterite mineral is interlock with few minerals pyrite, rutile, quartz, hematite, etc. XRD phase patterns showed the other minerals such as cassiterite, arsenopyrite, quartz, hematite, ilmenite, stibnite and pyrrhotite. Liberation study of Image J is the particle in raw image were separated by simple process that called “threshold”.
The main objectives of this process is to measured and calculate area of unliberated and liberated sample images from each sample based on their sizes. It can pixel and area of value statistics sample. Analysis of variance (ANOVA) by using Minitab 16 software were study responses of the Sauter Mean Diameter (SMD). Thus, it clearly shows that there is one significant effect, which is speed rate is 0.020 and time of the milling process, it is not significant effect since the p-value is higher than 0.0.
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CHAPTER 1
INTRODUCTION
Asia is the most enormous tin reserves and tin production in the world. The world tin supply mostly dependent on the Asian tin production. The production of Indonesian which fell from 35,000 tonnes in 1952 to 13,000 tonnes in 1963 because of world shortage and the period of high prices of tin in 1962-1966. Placer deposits are the most production of tin, based on the tin belt of Southeast Asia, primary tin deposits are concern to biotite or biotite-muscovite granite. The tin belt extends more than 1,500 miles away from Billiton (Belitung) Indonesian Island directly to Malaysia and Thailand and northern Burma (Sainsburry, 1969).
Figure 1.1: Tin-bearing areas of Southeast Asia (Taylor, 1979)
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Peninsular Malaysia the prime and the enormous tin producers in the world within the South Asian Tin Belt, alluvial or placer tin deposits are the major production from states of Selangor and Perak. The sources of alluvial deposits can be discovered to the ore bodies and primary tin veins that discover the exact place at contact zones of tin bearing granites and the other type of rocks. The weathering can produce these alluvial tin deposits that normally hampers geological work in tropical climates. 3-5% results from estimation of tin ore concentrate that produced from Malaysia produced from the hard mining activities. (Ariffin, 2009).
The primary tin deposit in Malaysia mined since 200 years ago, a rough calculation of the value over 70% of the Malaysian tin and produced 3–5% of tin ore concentrates at Gunung Paku. Gunung Paku near Klian Intan, Perak were fixed within the western Tin belt of Peninsular Malaysia and associated with biotite granite (184–230 Ma) of the Main Range Granitoid, which spread out to the southern part of Peninsular and Central Thailand. The primary tin mineralization at the Gunung Paku is mostly associated with widespread occurrence of sheet-like quartz veining systems parallel to the strike of the host rocks and confined within a narrow N–S trending fault zone.
The mineralogy and ore deposit formed within a thick sequence of metasedimentry rock that belongs to the Baling formation of Palaeozoic age. The most familiar metallic minerals that accompanied tin mineralization are cassiterite (SnO2), pyrite (FeS2), rutile (TiO2), arsenopyrite (FeAsS), chalcopyrite (CuFeS2), trippkeite (CuAsO4), scorodite (FeAsO), covellite (CuS) and other secondary ironoxyhydroxide.
Otherwise, the other slightly occurrences include trace amounts of complex lead-bismuth- antimony-molybdenum bearing minerals (Ariffin, 2009).
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Figure 1.2: Map of Gunung Paku tin deposits (Ariffin, 2009)
Tin metals has a low melting point with 232 oC, soft, non-toxic, chemically inert and malleable. The combination with all the properties has been used to create many products. Tin has many uses, tin plate (40-50%) is the majority of consumption of tin products. Tin-plated steel containers are great variety used for food preservation. Tin has long been used in alloys with lead as a solder (20-25%). The other uses are white metal and babbit together with antifriction metals (5-10%), tin is typically used in alloying with other metals, alloying tin with copper to form bronze (4-6%). Electro-platting can be done using a small coat of tin around the steel, aluminium and copper, protective coating on copper wire and electrical connection, i.e. tinning (4-6%) (Taylor, 1979).
4 1.2 Objectives
The objectives of this research are:
To determine mineral composition of Malaysian Tin ore using XRF.
To quantitative phase analysis of Malaysia tin ore using XRD.
To observe mineral morphology of Malaysian Tin ores.
1.3 Problem statement
The aim of the project is to characterization tin ore (cassiterite) form result of blasting area from different area by using a grab sample. Tin occurs in Malaysia in the form of cassiterite with varying amounts of associated minerals. The major sources of ore bearing cassiterite in Malaysia are the alluvial and placer deposits. This characterization covers the study of morphology features such as shape, size, growing patterns, as well as detailed in morphology analysis.
Tin is found in nature in the form of an oxide SnO2 commonly called cassiterite.
The degree of purity of the mineral cassiterite varies widely, tin oxide as mined is very impure carrying with other amount of impurities such as copper, lead, antimony, arsenic, iron, sulphur, bismuth and silica.
The different area of sample collected can cause the variation of the mineral composition. Arsenic is a chemical element which can be found in many minerals, usually combined with metals or sulphur. Arsenic is contaminant that can be hard to remove from the tin ore. The presence of copper, lead, antimony and bismuth in the ore render the metallic tin produced impure, in some cases it being impossible to make metallic tin over without refining the tin produced electrolytically to remove the impurities.
5 1.4 Scope of Study
The scope of this research will be performed using the sample of tin ore from the Rahman Hydraulic Tin Sdn. Bhd. where the properties of ore will be tested. The main characterization for this scope of study are bulk characterization and different size fraction characterization of tin oxide ore. These bulk characterization analyses including particle size analysis, analysis using quantitative phase analysis using X-ray Diffraction (XRD), mineral composition using X-Ray Fluorescence (XRF) and morphological study using optical microscope and Scanning Electron Microscope (SEM- EDX).
Mechanical sieve shaker is commonly being used to performed the laboratory study. Tin ore with different types and grades were proceed to these characterizations after sieve size analysis with obtained size of (-4.75) mm, (-4.74+3.33) mm, (-3.33+2.36) mm, (2.36+1.18) mm, (1.18+0.600) mm, (0.600+0.500) mm, (0.500+0.425) mm,
(0.425+0.300) mm, (0.300+0.2120) mm, (0.212+0.150) mm, (-0.150+0.090 mm, (-0.090+0.075) mm, and (0.075+(-0.075)) mm. The screening period can be controlled
by automatic timer.
After sieve size analysis done, every size of these samples was study for their properties that display by optical identification and mineral liberation was observed under polarizing microscope and scanning electron microscope (SEM) and the function of EDX is be able to detect semi-quantitative weight percentage of the particles. Image J software were used in particle analysis to calculate area and pixel value statistics to user-defined selections. The another function is can measure angle and distances.
1.5 Thesis Organization
The main content in this thesis are five chapters which is include introduction, literature review, methodology, results and discussion and the final chapter is conclusion and recommendation.
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Chapter one give some introduction that give detailed about the research background, problem statement, scope of study and the objectives in this work. The following chapter is literature review on previous works and the information about works regarding the work project.
The next chapter is shows the method how to arrange this project in a particular ways starting from the early stages until the last steps and get answer and completely the objectives research.
The most important part in this project is result and discussions are recorded in chapter four. All the works has been done on previous chapter are come out in this chapters and the reasons for this results.
Finally, the conclusion is made based on the results and discussion in this research. The recommendation for the future work also being explained in this chapter.
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CHAPTER 2
LITERATURE REVIEW
2.1 Introduction
Tin is a technologist's metal. In presence, tin also can be use in diverse application into all aspects of life and people somehow unaware of its presences.
Archaeologist revealed that tin was one of the earliest metal known to human society before history was recorded. Tin also give more practical uses and advance of mankind to human. The importance of tin was discovery long time ago of its hardening effect on copper to become bronze.
One of the uses alloy is can be cutting edge because the sharpened of surface and could be fabricated into efficient tools and weapons. From this early Bronze Age until nowadays, tin still give the various uses around the world and tonnage produced (Falcon, 1982).
2.2 Mineral Identification 2.2.1 Mineral Identities
In order to study about the rock and minerals, researcher must be able to identify and recognize the mineral deposits that contain in the rock and minerals. Once the properties of the mineral have been recognized, some of the test and useful knowledge can be applied to industrial properties and as advantage for researcher to counter the problems that might happen during the processing operations. As results, the mineralogical data is very valuable for the rocks and minerals. The data are required and be used to design the flowsheet to control the mineral treatment operation and can reduce the problem occurred during operation.
8 2.2.2 Mineral and Their Classification
Most of the minerals in a crystalline structure and clearly stated of chemical composition, the chemical composition of minerals is slightly varying and it only within the certain limits. Crystal structure are referred to the crystalline mineral that contain three-dimensional positioning of atoms. The minerals are divided into the various group of chemical classes that made up anionic part of the formula. There are the most important groups which is include, (a) oxides and hydroxides (cassiterite, SnO2, hematite, Fe2O3; rutile, TiO2), (b) native elements (gold, copper, diamond, bismuth, and silver), and (c) sulphides and sulphosalts (galena, PbS; sphalerite, ZnS; chalcopyrite; CuFeS2; chalcocite, Cu2S) (Jain, 1987).
2.2.3 Mineral grain size distribution
Once the minerals liberated from its rocky matrix, the estimation of grain-size distribution can be done. Minerals are large grains usually liberated at relatively large particle sizes while the fine grains liberated at very fine particle sizes. As comparison, cost of liberation of small grains are more expensive than large grains liberation process.
With that, the engineer can easily estimate costs of liberation procedure and also cost of concentration process are needed (Jones, 1987).
2.2.4 Characterization of Ore Minerals.
The mineralization of tin at Gunung Paku are very simples. Based on photomicrographs that tin and sulphides were selected bearing quartz vein and ores from plant concentration. The other minerals that contain after polish section were analysed commonly pyrite, cassiterite, chalcopyrite, arsenopyrite, trippkeite, magnetite and chalcocite. Analysis of Energy Dispersive X-ray (EDX) shows the few by product minerals in tin-bearing mineralized vein are Pb-, Cu-, Bi-, and Sb- bearing minerals. The minerals such as As, Fe, S and Cu exist in a various type of samples which is result from
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relationship of mineralization of tin. The minerals that rarely found in a mineralization of tin include nukundamite (CuFe)S and unnamed mineral of (CoFe)AsS.
2.2.5 Physical Properties of Minerals
In order to recognized the physical properties of minerals, it not depend on the chemical test, but most important thing is the positioning of atoms in the crystal structure.
There are a lot of physical properties of minerals can be observe, colour, transparency, lustre, specific gravity, hardness, cleavage, fracture, magnetic properties and optical properties.
All the properties can be used for determined the minerals, but to get the best result by using some chemical and also crystallographic information. Mostly chemical are used in ore processing, liberation is most important factor during processing because it can reduce the amount of chemical to be used. The waste and the valuable minerals shows the differences in behaviour which affords the method for separation. Table 2.1 shows the world’s produces and consumers in tin industries. The physical and chemical characteristics of tin also showed in the table and uses and the occurrences of tin ore.
(Jain, 1987).
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Table 2.1: Tin in brief (The International Tin Council, 1974).
Tin
Tin Metals Low melting point, chemically inert, non- toxic and soft
Tin Uses Tinplate: 40-45%
Solder: 20-25%
Bearing metals: 5-10%
Bronze : 4-6%
Tin Ores Only economic ore is cassiterite (tin oxide, SnO2). 78.6% of tin. Brown color,
6-7 mohr scale hardness and specific gravity is 7.0
Ore Occurences Primary lodes or as a secondary alluvial or elluvial deposits.
Main Producers (1973) Malaysia: 38.9%
Bolivia: 15.4%
Indonesia: 12.1%
Thailand: 11.2%
Australia: 6.0%
Others country: 16.4%
Main Consumers (1973) U.S.A.: 27.9%
Japan: 18.4%
U.K: 7.9%
Germany, F.R: 7.5%
France: 5.3%
Others : 33.0%
International Control International Tin Council (I.T.C) Fourth International Tin Agreement (from 1st July 1971) signed including 7 major world producers and 22 consumer nationwide. However, the largest world’s
consumer of tin is U.S.A.
11 2.3 Geology of Tin
2.3.1 Tin
Cassiterite (SnO2) usually known as tinstone. Cassiterite is the only one of the abundance minerals in the earth’s crust have a high commercial value. Cassiterite shows high percentage of tin when its chemically pure with 78.6 %. Whilst, the percentage slightly varies between 73% to 75% when it contaminated with impurities (Barry, etc. al 1983).
Tin give massive important role in modern technologies. Tin shows various properties, non- toxicity, low melting point, malleability, softness, anti- friction qualities and corrosion resistance. Tinplate shows 40% of world production of the main uses of tins in a coating industries, follows in uses of solder shows one-quarter of consumption.
The other applications of tins in bearing metals, bronzes, organo-tin chemical and pewter (Robertson, 1982).
2.3.2 Physical Properties of Tin.
Tin or Stannum with chemical formula symbol of Sn, tin is a one of the ductile metal with white color slightly similar to silver sometime darker based on the geological pattern (Barry, etc. al, 1983). Tin has a lower melting point compared to iron. The melting point and boiling point of tin is 233°C and 2630 °C. Tin also become production in float glass because of the lack toxicity liquid tin and also lowering in vapour pressure (Wright, 1982). Physically weak and looking highly lustre that can be scratch by finger nail and easily cut with a knife. Tin is very malleable, chemically inert that can use in chemical properties and it absolutely non-toxic (The International Tin Council, 1974).
Well-crystallized cassiterites are close enough to SnO2 in composition and minor niobium and tantalum but some has to 3 percent Fe+3 substituting for Sn. The material
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widely called wood-tin showing botryoidal and concentric, reniform shapes, and radially fibrous internal structure, lowering in specific gravity and brown colour when saw using with naked eyes and, commonly contain inclusions of silica and hematite. Colour is the best methods to differentiated the minerals but sometimes it more difficult to identified because it mostly similar. Cassiterite has the high specific gravity 6.98-7.1g/cm3, which is highest among the common light-colour, non-metallic minerals. (Gascoigne, 1914).
Tin oxide is represented with chemical formula of SnO2 which is referred to cassiterite mineral and the only economically commercial ore of tin. Total amount of tin contain in cassiterite is 78.6% and the others is oxygen. Cassiterite consist of different colour from white to black, gray, reddish brown, rarely colourless but mostly found brown in black in colour. The crystal structure is tetragonal system which is transparent when the light colour but not typically brittle so it can be used as gemstones and the hardness on mohs’ scale is about 6-7 (Barry, et. al, 1983).
2.3.3 Mineralization of Tin Ore in Malaysia
The geology of Peninsular Malaysia that contain of two major granitoid, the first one is the Eastern Province granitoid and the Late Triassic Main Range granitoid.
(Gobbett & Hutchison, 1973; Hutchison,1977; Cobbing, 1986). The Late Triassic Main Range granitoid shows typically S-type and made up biotite granite, which contain characteristics ilmenite siries (Schwartz et al., 1995). The west of Raub-Bentong suture in Peninsular Malaysia are The Main Range and spread out to the central Thailand (Mitchell, 1977).
The Eastern province equal amounts of I-type monzogranite (metaluminous hornblende-biotite granites) possibly derived from an igneous precursor rock and S-type monzogranite (peraluminous biotite granite) with a metasedimentary. Mostly, the
13
mineralization of tin in Malaysia associated with granite, the belt of Peninsular Malaysia always in a N-S orientation. The other minerals that associated during mineralization of tin is highly concentration is Silicon Dioxide (SiO2), Cassiterite (Sn), Rubidium (Rb), Potassium Oxide (K2O) and Uranium (U) (Ariffin, 2009).
The tin-bearing zone at Gunung Paku obviously belief as structurally controlled mineralization and stratabound distribution. In order to employed the mineralization zone, parameter such as mineralogy (alteration and sulphide minerals), colour of the mineral, concentration and the occurrence of the cassiterite must be looking attentively.
Structurally, Gunung Paku tin deposit known as the Intan fault zone is obviously restricted in a fault zone of about 200–300 m wide (Khoo,1989).
Cassiterite are the most important ore of tin, it is one of the abundant minerals in the earth crust and one of a very few tin minerals. Tin are commonly occurring in high- temperature hydrothermal veins and commonly associated with siliceous igneous rocks.
There are a common minerals associated during mineralization of tin such as quartz, bismuth, muscovite, wolframite, tourmaline, fluorite, arsenopyrite, and molybdenite. The common alluvial minerals contain in areas of many greisens is cassiterite. Greisen is the coarse-grained rock contain these minerals and formed by hydrothermal alteration of granitic rocks (Ariffin, 2009).
2.3.4 Tin Ore Deposits in the World
The Southeast Asian Tin Belt is the sufficiently great tin producer in the world.
9.6 million tonnes of tin that indicated since 1800, around 54% of world’s production of tin majorities from the Southeast Asian countries including Malaysia, Thailand, Indonesia, and Myanmar. 10% of the world’s production of tin are from other countries in South China, Bolivia and Cornwall (England). Rondonia tin in Brazil provide only 2%
14
of the world’s tin production is the tin-producing giant the future. The largest ore reserve and the production of tin increasing in some recent years (Schwartz, 1995).
Figure 2.1: Map of mineralization tin in world (Lehmann, 1990).
There are five tectonostratigraphic that recognized in Southeast Asia gradually gathering in the Mesozoic and Paleozoic ages. Sibumasu block (Sino-Burma, Malaya and Sumatera) and on the East Malaya block that are The Southeast Asian Tin Belt were located. Other a fault-bounded area or region with a characteristic stratigraphy are southwest Borneo, South China and Indochina. (Rajah, 1995).
15
Figure 2.2: Map of tectonostratigraphic terranes of Southeast Asia. (Schwartz, 1995).
Cassiterite mainly found in two type of deposits, first one is it occurs as a primary accessory a part in a late stage of granitic intrusion and mostly found in a quartz vein such as granite and also in a surrounding rock. The second type is occurring as alluvial or placer deposits and detrital deposits (Falcon, 1982).
The association of cassiterite with highly acidic granitic rocks, it is significant fact that at not a single tinfield in the world has cassiterite been found in situ except near granite or granite rocks because cassiterite minerals has chemically stable and the primary deposits of tin will undergo secondary accumulations to become the major source of tin (Falcon, 1982).
16 2.4 Occurrences in Nature
Cassiterite is a very limited found in nature. It basically associated with granite during the formation of tin were intruded and molten into formation of sedimentary rocks.
When granite was formed along the quartz vein and it from liquid state to solid state and finally become a vein that contain a lot of metals ore. Cassiterite usually in the form of sulphide and it associated with a few minerals (The International Tin Council, 1974).
80% the world production of tin reveal the result were come from the alluvial and eluvial deposits but not from the primary deposits. Cassiterite having a high specific gravity, great resistance in mechanical and chemical weathering. The concentration of the tin minerals from the primary deposit is the result from the tin-bearing vein and erosion of the host rock (Barry, 1983).
The minerals will be shifted by weathering processes and water to the stream or river. Collection of valuable minerals formed by process during sedimentary process to be collected in a places, the minerals particle must be dense than other minerals such as quartz. The cassiterite move in short distance from its sources because there are not too advanced in the weathering of granite while the crystal structure of cassiterite are rounded and smooth by the action of water. 0.015% of tin that produced from the alluvial deposits, elluvial deposits indicate a nearby source of primary ore (The International Tin Council, 1974).
2.5 Site Project Background
2.5.1 Rahman Hydraulic Tin Sdn. Bhd.(RHT)
Gunung Paku located near Klian Intan, Perak, is a primary tin deposit in Malaysia mined since 200 years ago have been operated by Rahman Hydraulic Tin Sdn. Bhd.
Incorporated since May 1907 and nowdays, RHT was controlled by Malaysian Smelting
17
Corporation (MSC), the biggest tin smelter in the world. It contributed over 70% of the Malaysian tin and recently produced 3-5% of tin ore concentrates.
RHT is one of the largest open pit elluvial which is semi hard rock tin mine. In order to increase their tin resources, exploration of new reserves, upgrade the drilling programmes and development of ore processing. The Klian Intan district, which is the Gunung Paku tin deposits are strategic at the centre of sporadic tin mining. It located within the western Tin belt of Peninsular Malaysia which means associated with biotite granite (184-230 Ma) of the Main Range Granitoid which extends to the southern part of Peninsular and the central Thailand (Malaysian Smelting Corporation Berhad (MSC), Annual Report, 2011).
The coordinates of RHT mine pits 5o38N,101o50E and total area of the mine about 1km×3km of areas. The primary tin at Gunung Paku is mainly associated with widespread of quartz veining system, which the belt lying parallel to the strike of the host rock of the areas. The Gunung Paku primary tin deposit and nearby mines covering an area greater than 1500 acres have been operated by Rahman Hydraulic Tin Limited.
18
Figure 2.3: The location maps of Gunung Paku tin deposits (Ariffin, 2009).
Figure 2.3 shows the location of the Gunung Paku tin deposits of Rahman Hydraulic that located near the Thailand border. The grade of ore is very low which is their average grade of ores are low around 0.05% Sn. Mostly the ores are weathered rock, so the ore are soft and very suitable for hydraulic operation. The monthly production about 180,000- 200,000 kg at 2-5 kg m-3 and total average production is 6 tonnes per days (Ariffin, 2009).
RHT is one of the largest open pit elluvial which is semi hard rock tin mine. In order to increase their tin resources, exploration of new reserves, upgrade the drilling programmes and development of ore processing. Mining operation starts with drilling and blasting, excavating, loading and hauling using bulldozers, excavators, and off-highway
19
trucks. The ore material is hauled and dumped to the stockpiles at five ore processing plant, while the waste materials were dumped at the specific places that called waste dumps. Using 6-lane Palong at the processing plant make some improvement of 20% to production of tin.
Table 2.4: Production of tin-in- concentrates 2010-2011 (Malaysian Smelting Corporation Berhad (MSC), Annual Report 2011)
2011 2010
Production of tin-in-concentrates (Tonnes) 2,010 1,769
Profit before tax (RM million) 59.01 28.23
20
CHAPTER 3
METHODOLOGY
3.1 Introduction
This chapter will be explain the flow of the research work, used and details of raw material sample preparation, procedure, site and laboratory sampling, design of experiment and ore characterisation method. In the site sampling procedure, grab sampling was taken from blasting product from the exploration section of Rahman Hydraulic Tin Sdn. Bhd.
After sampling, sample were undergoing comminution process such as primary and secondary crushing and milling process. The significant effect of stirring speed (X1) and the milling time on particle mean size. The characterization of raw material and mill product were designed based on Design of Experiment (DOE) using Minitab 16 and analysing by X-Ray Fluorescence (XRF) to determine the mineral composition, X-Ray Diffraction (XRD) used to identify quantify phase.
Visual, optical, observation and the used of SEM, method were discuss in detail includes polish section preparation. Observation of morphology and texture by using scanning electron microscopic (SEM-EDX) fitted with Energy Dispersive X-ray. Figure
3.1 shows the overall flow chart of the research on how the experiment were conducted.
21
Indicator:
Figure 3.1: A flowchart representing the overall experimental work.
Initial Process Process Step Process End Data of analysis Flow of process Sample as received area (5×4) cm from Rahman Hydraulic Tin Mine.
Total weight sample 13.300 kg
Sampling
Crushing, feed size <5cm
Sieving
Characterization of tin ore
Morphology study Polarizing Microscope
X-Ray Diffraction
Phase identification and quantification
Loss On Ignition (LOI)
X-Ray Fluorescence (mineral composition) Mineral Liberation study
Scanning Electron Microscope (SEM-EDX) with Energy Dispersive X-ray.
Design of Experiment
(22 +3) Particle Size
Distribution Analysis
Keep for references -5mm
22 3.2 Raw Materials
The raw materials, tin ore were collected from Rahman Hydraulic Tin Sdn. Bhd.
Rahman Hydraulic is a Malaysia’s long established and largest operating open-pit alluvial tin mine, that located at Klian Intan Town, District of Pengkalan Hulu, Upper Perak, West Malaysia. The samples were collected by using grab sampling method. In order to make a representative sample, sample are taken at the different point. Figure 3.2 shows the Rahman hydraulic Tin Mine location and the arrows shows the area where the sample are collected.
Figure 3.2: Area of site sampling at Rahman Hydraulic Tin Mine
Grab sampling can be used on a stope after blasting process at a mine, the samples are taken at the random positions that it being assessed for the presence of valuable minerals. Grab sampling also can be used to collect preliminary information to help
23
identified the valuable minerals or not. The measured size of the sample is approximately 5 cm (<5 cm).
Figure 3.3: The samples from Rahman Hydraulic Mine. 3.3 Crushing
Comminution of mineral is conventionally performed by crushing and then grinding. Crushing is usually carry out in several stages to reduce particle size in order grinding process can be carried out to achieve adequate liberation (Wills 1990).
3.3.1 Cone Crusher
The Marcy Gy-roll Cone Crusher produced from Svedala Industries, Inc, Pyro Systerm. United States was used in thesis project. Basically size feed of cone crusher not exceed 150 mm and the output is the range less 12 mm in average diameter. The purpose of this crushing is to liberate the rock or ores to an adequate size which all the more effectively for grinding process (Jain, 1987).
24
Figure 3.4: Marcy Gy-Roll Cone Crusher are high reduction efficiency and give very good product shape.
3.4 Laboratory Sampling
Sampling is the most imperative step and should be done at first before the sample was sent to another process or laboratory analysis. The sampling process of obtaining small amount of quantity that can be representative of average of some large amount.
Purpose sampling is to divided the sample and mixed them homogenously. 20 kg tin or was poured into a conical heap upon a solid surface (e.g, a steel plate).
The output from the cone crusher were put on wide plastic blanket in order to get the homogenous portion when doing sampling. The sampling techniques involved were cone and quartering sampling method and riffle splitting method. There are two stages of sampling method were applied; cone and quartering sampling and john riffle sampling.
3.4.1 Cone and Quartering
This is done by utilizing the coning and quartering technique, this method used for splitting a bulk sample to obtain a sample of several kilograms.
25
The portions chosen might be further reduced by a continuous process until the specific size of sample is obtained. The ore is scooped into top surface of the cone shaped pile, thus marked it into four segments which is A, B, C and D, the process coning and quartering repeated until the whole sample are homogeneous, mixed and proper sample size needed for a certain test is obtained (Jain, 1987).
The material divided into four parts which is two part being used as test project.
Two opposites part were taken away from the sample and keep as a references, but the other two opposite quarter were taken to next processes. The sensibly utilized this technique since general cost are not costly and sample size obtained from large bulks.
Figure 3.5: Coning and quartering method of feed materials.
(https://www.researchgate.net/figure/283496833 fig4 3.4.2 Jones Riffle Splitting
The riffle splitting usually used for small and fine sizes samples. This splitter comprising the two sets of scoop opening on both sides and equivalent width to separate the materials. As shown in the Figure 3.6. The material slowly poured through the riffler that passing through the riffle box, which divide it into two equal halves which will received into two trays and collected in box which placed either side of the unit. One half turning into a specimen ventures, and half one kept as references. Continue pouring the
26
sample at the centre of the riffler splitting to reduced number of material losses. Riffle box can only use on dry sample.
Figure 3.6: Jones Riffle Sampler 3.4.3 Sieving
In order to obtain the size distribution of tin ore sieving method were used by using the different size aperture (Jain, 1987).
The right approaches to choose the sieves size by using the ratio of the aperture widths of adjacent sieves was the square root of 2(√2=1.414), which means (N/√2), N is the gap width for the first materials passing. The sieving procedure commonly ran 15 minutes for each samples when the all samples take right around 45 minutes to completed this process. Endecotts EFL2000 sieve shaker is used for in laboratory and very heavy duty applications, it competent for the large bulks of sample without loss of execution.
The most critical safety measures must be taken during this process is wear face mask and the earplug to keep away from small dust particle enter to the mouth and avoid the noise that cause ear damaged. The particle size was analyse after the sieving process.
27
The size distribution of particle in minerals and the quantitative data were determined by the sieve size analysis.
Sieve analysis is to obtain the particle size distribution of a raw sample and to determine the percentage of the materials which less than 75 µm. Then, the percentage of weight in each sieve size must be calculated to get the results. The raw materials must keep in dry conditions to avoid blinding when sieving process.The biggest single problem when sieving powders is mesh blinding, where the apertures of the mesh screen are blocked. Blinding is most serious when doing in a small aperture sieving size. Screen blocking or blinding is a common problem when sieving fine powders on screen of 300 µm and below. Sieve sizes are used 4.75mm, 3.35mm, 2.36mm, 1.18mm, 600µm, 500µm, 425µm, 300µm, 212µm, 150µm, 90µm, 75µm and -75µm. The sieve size are arranged in ascending order start from bottom to the top sieve. Record the time for sieving in 15 minutes and after that weighed the mass of material retained.
3.5 Mineral Identification using Optical Microscope
All the polished section was observed under the optical microscope.
Determination of opaque and transparent mineral by using optical properties. The polarizing microscope MT9430 Meiji Techno Co., Ltd import from Japan was used to identified crystallographic of individual minerals. Magnification used for these sample is 5X, 10X, 20X, 50X, and 100X magnification. The digital camera to capture the image of software of Isolution DT was used to observed surface and texture of minerals.
28
Figure 3.7: Endecotts EFL2000 vibrating sieve shaker 3.6 Loss On Ignition (LOI)
Loss on ignition (LOI) analysis is used to calculate the percentage organic matter contain (%OM) and carbonate content in sample, thus LOI value is very important for the XRF analysis. This process started with heat the empty crucible in a Electic Carbolite Furnace. Three empty crucible were filled up with sample. The weight of sample is 2.0000g. The three crucible with the sample were marked with A, B, and C. The sample was keep running in high temperature is 850 oC for aggregate of 6 hours and 50 minutes including cooling time. The heating process was carry out with increasing temperature of 10°C/min until the ignition temperature of 850°C (Robertson, 2011).
The samples were left at room temperature with 10°C/ min after heating process completed. LOI result are very important because directly used for the XRF analysis. The loss on ignition of the dry mass of a solid sample expressed in percentage shall be calculated from the formula.
29 LOI% = 𝑊₂−𝑊₃
𝑊₂−𝑊₁× 100 Equation 3.1 Where,
LOI is the loss on ignition of dry mass of solid, in percentages (%);
W₁ is mass of empty crucible in grams;
W₂ is mass of crucible containing the dry mass in grams;
W₃ is mass of crucible containing the ignited dry mass in grams;
3.7 Design of Experiment (DOE)
Design of Experiment (DOE) is an intense tool that utilize in a variety experimental situations. DOE allows for multiple input factors to be manipulated determining their effect on a desired output. DOE empower distinguish imperative interactions that might be missed when experimenting with one factor at all time. All possible combinations can be investigated using full factorial.
Overall process of DOE is transformation input to output. In order to get the best performance of experiment, input process intentionally must change to observed the changes in the output process. In this project, Minitab 16 software was used because it very simple, easy to used and it can support many advance methods. Minitab demonstrate statistical and graphical data with DOE techniques.
Full Factorial = 22 + 3 = 7
In Design of Experiment, full factorial was used to approach the experimentation.
Each process of parameter was studied at 2 level which means (-) low level represented by -1 and (+) high level represented +1 and the centre point is 3. The variables that used in this project is speed rate and time, +1 and -1 are the actual process parameter in the experimental layout. Stiring speed (X1) and milling time (X2) will be analysed on mean
30
particle size. The total of experiment should be run is 7. Then, next steps are run the experiment using Planetary Ball Mill based on the result of DOE. (Jiju Antony, 2014).
The purpose use planetary ball mill because it can avoid the ore contaminated during the process milling and depend on the grinding media that we used. In this project, stainless steel was used as a grinding media because good abrasion resistance, high hardness and high toughness and the most important is it can avoid contamination of minerals. 20 mm diameter of ball size and only 10 balls that used for grinding media for 50 g weight of samples. Based on table 3.1, shown the design table of DOE representing the overall experimental work by using Minitab 16 software.
Table 3.1: Design table of Design of Experiment (DOE).
C1 C2 C3 C4 C5 C6 C7
Standard Order
Run Order
Centre Point Block Speed Rate (rpm)
Time (min)
Code
4 1 1 1 400 30 T43
6 2 0 1 250 20 T22-2
3 3 1 1 100 30 T13
5 4 0 1 250 20 T22
1 5 1 1 100 12 T11
2 6 1 1 400 12 T41
7 7 0 1 250 20 T22-3
3.8 Preparation of Polish Specimens
The size range of the sample is 4.75 mm, 2.36 mm, 0.600 mm, 0.425 mm, 0.212 mm, 0.090 mm, +0.075 mm and -0.075 mm. All the sample were observed under the polarizing microscope to observe the minerals. Before polishing has done, there are following method should be comprising:
3.8.1 Specimen preparation and mounting
Epoxy resin and hardener are used to get the strengthened the impregnation of specimens for samples 1, 3, 5, 7, 9, 11, 12 and 13 under the room temperature. Specimen were mounted in the standard-size block of epoxy resins. This done to make sure easier
31
to handling and to standardize the finished specimens size that all the specimens fit specimen’s holders. The ratio of hardener and epoxy resin is = 1:1. Then, these mixtures were stirred in two minutes to get homogenous and pour the mixture into the mould holder. The specimens were kept under the room temperature in three hours.
3.8.2 Grinding on the flat surface
The specimens were removed from the moulds after completely hardening. Then, the face was then ground on the sand paper. The approximately grit size of sand paper is 180, 240, 360, 420, 600, 800, 1000, 1200, and 2000 are used for grinding process to get flat and smooth surface. The water is important during grinding process to reducing scattered of the flat surface and keep easy during microscope analysis.
3.8.3 Polishing on flat surface
In this process, alumina oil is used polishing procedure. An auto-polishing machine that can run only 5 specimens in one period. Two hours are enough to stop the machine and to ensure the smooth and clean surface for identification of minerals.
3.9 Characterization of Tin Ore
Characterization of minerals involve to study in term of their size, mineral composition, chemical composition, mineral liberation, phase analysis, and morphology.
Thus, the analysis involved in this characterization is particle size distribution (PSD), XRD, XRF, SEM-EDX and Image J give more understanding about the particle size distribution and mineral composition of the sample.
3.9.1 Particle Size Distribution (PSD)
After milling, the particle size analysis was analyse using Malvern Instrument Mastersizer particle size analyser or HELOS to determine the quantitative data about the size of samples. Malvern Instrument are mostly used for industrial application because of new result emulation tools make easier to process of transferring method compared to wet
32
particles size techniques. This analysis is very important to obtain the data about the particle size distribution in a raw material. Sieving is carried out with wet or dry materials and the sieves commonly agitated to expose all the particles to the opening (Wills, 1979).
3.9.2 Composition by using X-Ray Fluorescence (XRF)
X-ray fluorescence (XRF) the most powerful qualitative and quantitative analytical for elemental analysis and mineral present of materials. It suitable for measurement of elemental composition weight of solids and solutions (Anzelmo 1987 Part 1). The chemical composition in tin ore sample was determined using RIX 3000 XRF spectrometer by Rikagu.
Two types powder sample were analysed by XRF, sample A and sample B which is tin ore sample at the 75 micron and -75 microns. Approximately 25 grams weight of sample that required for XRF analysis. The sample that undergo XRF analysis is product from the sieving process. The fine sample that ensure smooth reflection of x-ray to the surface of the samples. Ball mill and Rig mill that made of iron or any metals are not suitable to grind this samples because there is possibility contamination with iron in a sample. Contamination of iron will increase the percentage of Fe2O3 in the result of XRF and it give the incorrect data.
3.9.3 Identification and Quantification Phase Analysis by X-Ray Diffraction (XRD) X-ray Diffraction (XRD) one of the most accurate and directly method to identify crystalline compound and also to quantify (determined the existence of phase in powder or certain materials). XRD are non-destructive analytical method which is for quantitative and identification phase analysis. Sample powder must be grind until 75 microns and compact to obtain a flat suface. (Koenig, U. 2007).
Full-profile of Rietveld method was founded for the removing impurities of crystal structure parameter (Rietveld, 1969). All the sample are grinded using stainless
33
steel Planetary Ball mill to reduced size and obtain for XRF analysis. XRD analysis were conducted using D2 Phase and D8 Machine by Bruker. The scan range is (2θ°) for the sample in range 10-90o, step size is 0.0300 (o2Th), scan step time is 33.000 (s) and receiving slit size is 0.1000 (mm). Data measurement was analysed using the software of Pan Analytical Expert Highscore Plus and Pan Analytical ICSD database for the identification of minerals. Each minerals phase were present in unit weight percent after Rietveld refinement.
3.9.4 Scanning Electron Microscopy (SEM)
Investigation of samples by SEM-EDX allows to identification of individual minerals, either in situ within a polished section prepared from a rock sample, or a sample mount prepared from concentrate or other processing product. SEM-EDX is used to observed morphology and mineral qualitative phase analysis. Before undergo SEM, the sample need to coating with gold to cover the specimen with a thin layer of conducting materials. Back- scattered electron imaging were used to identified the traces element and minor minerals that cannot be observed by using conventional microscopic procedures (Cook, 2000).
The morphology can be observe using backscattered scanning electron microscopy attributes and mineral fabrics in appreciably more detail than conventional optical microscopy (e.g., Kringsley et al,1998). Quantitative analysis were obtained by using energy dispersive system (EDX). Quantitative method acquired to observed mineralogical distribution pattern and full mineralogical characterization of the samples.
The possible minerals that spotted using EDX usually to identified the composition of samples
34
3.9.5 Liberation Studies by Image J Software (Imaging Process)
Image J software are used for liberation study and particle analysis in this project.
Image J support the different standard image file system which including 48-bit colour composite for image support. The advantages of image J is can open variety image format has long been important features. Image J program’s interface with tiny toolbar which is contain all available command in it. It can open each image in a different window.
Image J contain a useful tool for image processing including standard image filter such as mean, median and histogram manipulations. Area and statistics value were recorded and the distance also recorded. Line profile and density histogram must be calculated, “threshold” is a process to separated raw image from the background. The important thing is to measure the un-liberated and liberated minerals image based on the sizes (Collins, 2007).
35
CHAPTER 4
RESULT AND DISCUSSION
4.1. Introduction
Mineralogical process means the practical of the mineralogical knowledge to estimate how an ore can be best be mined processed and to support mineral exploration.
Process Mineralogy usually apply in an ore characterization and process design optimization to reduce or lowering the operational cost. The purpose of process mineralogy is to estimate and to recognize characterization process of an ore that are mineralogical controlled and to consider that can give benefits or disadvantages. Process mineralogy is utilized in all stages of mining cycle including exploration process, mine planning, mineral processing and tailing management.
In mineral exploration, process mineralogy is used to identify the ore minerals, and make early estimation of what the primary problem to excavated the minerals.
Mineralogical knowledge can be used to provides indicator or to identify the location of the ore bodies. The result of the experimental work conducted in the chapter 3 were presented and discussed in this chapter. In this chapter, the result and discussions of the whole methodology basically story about the process mineralogy was carried out. Mineral composition and phase analysis can be obtained from the result of Xrf and Xrd. The important part in mineralogical study and morphology by using optical microscope, polarizing microscope and scanning electron microscope. Liberation study were determined the area and size of mineral by using Image J software are discussed in this chapter.
36 4.2. Sieve Size Analysis
After completing the comminution using cone crusher, the sample of tin ore were fed through sieve shaker in order to determine the weight in each size fraction. Sieve size analysis was done for representative raw sample with total mass 5428.17 g.
The result of sieves analysis is presented by semi logarithmic cumulative plot known as particle size distribution. The percentage finer are plotted in an arithmetic scale and the corresponding particles diameters in a log scale. The particle size distribution curve was plotted using the data from Table 4.1 below. Table 4.2 shows the particle size distribution of raw materials.
Table 4.1: Summary sieve size analysis at D10, D50, and D90. Type of Sample Percentage Passing (%)
D10 (mm) D50 (mm) D90 (mm)
Tin ore 75 micron 0.19 0.73 1.99
Sieve size analysis is the number of particle that fall into each size range as a percentage passing from the total number of all sizes in the samples. D10 and D90 shows particle size distribution at 10% and 90% cumulative from 0 to 100% undersize particle size distribution.
Mean values are defined as the value of particle diameter at 50% in cumulative distribution or half of population resides above the point, and half resides below the point.
For particle size analysis, the median that called D50 or X50 depend on ISO guidelines.
The D50 splits the distribution with half above and half below this diameter (Weiner.
2011).
37
0.01, 90.00 1.99, 90.00
1.99, 0.00
0.01, 50.00 0.73, 50.00
0.73, 0.00
0.01, 10.00 0.19, 10.00
0.19, 0.00 0
20 40 60 80 100 120
0.01 0.1 1 10
Cumulative percentage passing (%)
Sieve Size (mm)
Table 4.2: Particle Size Distribution of tin ore samples
Sieve Size (mm)
Weight Retained (g)
Cumulative Retained
(g)
Cumulative Mass Retained (g)
Cumulative Mass Passing
(g)
4.75 12.38 12.38 99.77 0.23
3.35 157.36 168.74 96.87 3.13
2.36 1180.00 1349.74 75.13 24.87
1.18 1745.00 3094.74 42.99 57.01
0.60 1025.00 4119.74 24.10 75.90
0.50 165.76 4285.50 21.05 78.95
0.42 85.02 4370.52 19.48 80.52
0.300 302.70 4673.22 13.91 86.09
0.212 534.60 5207.82 4.06 90.94
0.150 47.87 5255.69 3.18 96.82
0.09 116.84 5372.53 1.03 98.97
0.075 11.20 5383.73 0.82 99.18
-0.075 44.44 5428.17 0.00 100.00
TOTAL 5428.17
Figure 4.1: The graph of particle size distribution curve of tin ore sample.
