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Control of Slimes in Problematic Ores: Selective Cu/Au/Ag Mineral Separation. S. Murthy Khandrika Columbia University Cytec Industries, Inc. Center for Particulate & Surfactant Systems (CPaSS) IAB Meeting New York, NY August 2009. Challenge/Goal. Challenge:
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Control of Slimes in Problematic Ores: Selective Cu/Au/Ag Mineral Separation S. Murthy Khandrika Columbia University Cytec Industries, Inc. Center for Particulate & Surfactant Systems (CPaSS) IAB Meeting New York, NY August 2009
Challenge/Goal • Challenge: • Processing problematic ores containing altered silicates and slimes (fines) • Goal: • To develop a scientific understanding of the above processing problem • To develop robust chemical methodology for better metallurgical performance (Cu, Au, Ag) Hypotheses/Objectives • Hypotheses: • Poor separation of desired minerals attributed to: • Presence of altered silicate (Mg silicates) slimes (fines). For example, • Chlorite: (Mg,Fe,Al)6(Al,Si)4O10(OH)8 • Talc: Mg3Si4O10(OH)2 • Aqueous species generated from these silicates • Certain Polymeric Modifiers can mitigate these adverse effects • Objective: • Study the effect of functionalized polymeric modifiers in improving selective recovery of value minerals 2
COMPLEX Copper ore CONTAINING ALTERED SILICATES Si Cu • EDX data: • Value mineral (Cu) content very low • Large quantity of altered silicates present • Challenge is to selectively separate • value mineral (Cu) Ca Mg 3
COMPLEX Copper ore CONTAINING ALTERED SILICATES Talc ? Mica ? keV EDX spectrum keV EDX data shows possible presence of talc or mica. Fibrous mineral also noticed. EDX spectrum 4
Modifiers COO - SO-3 COO - Cyquest 40E Carboxy methyl cellulose • Some of the functions of a modifier: • Dispersion of slimes • Prevention of heterocoagulation • Viscosity reduction 5
One possible mechanism of modifier operation Slimes Cu Cu Cu Value mineral No Modifier Cu Cu Modifier Simplified operation of a modifier 6
Effect of Modifier 40E on Cu recovery and grade Copper Ore 1 Cu in ore: 0.04% Au in ore: 1.3 g/t * Copper recovery improved by 15% upon using modifier 40E 7
Effect of Modifiers on Cu and Au Recoveries Copper Ore 2 Polymer : 150 g/t pH: 9-10 Polymers contain carboxyl and sulfonate groups Cu in ore: 0.3% Au in ore: 0.81g/t * Copper and gold recoveries improved upon using modifiers 8
SUMMARY & ConcluSIONS • Polymeric modifiers • Improved value mineral recovery and grade in different ores • Effective in concentrating low grade ore • Performed better than CMC Mineral particle-reagent interactions R&D Impact Knowledge-base: Particles Dispersion Solution chemistry Reagents Further develop: New reagents Greener, sustainable technologies Applications: Pharmaceuticals Cosmetics Drilling Mineral Processing Food Pulp & Paper 9
Future Plans • Fundamental and applied studies • Identify pathways for adverse effects. • Elucidate the mechanisms involved. • Spiking experiments on “good” ores. • Solution chemistry studies to identify species responsible for lower recoveries. • Structure–activity relationships of new modifiers Acknowledgement Cytec Industries, Inc. Newmont Mining Corporation Vale Inco THANK YOU 10