INLINE PRESSURE JIG FOR DIAMOND PRECONCENTRATION: THE FACTS AND THE MYTHS

Transcription

1 INLINE PRESSURE JIG FOR DIAMOND PRECONCENTRATION: THE FACTS AND THE MYTHS Diamonds Rockwell Diamonds, February 2010 Ben Salter Technical Sales Engineer GEKKO SYSTEMS

2 INTRODUCTION Working with De Beers and other diamond producers since Conducted 4 major site test programs for the IPJ. Feed-on tracer tests Heavy liquid analysis Diamond balance tests of IPJ tailings and concentrate using DMS as the standard Worldwide installations in South Africa, Canada, Namibia, Tanzania, and Angola, Sierra Leone, Australia.

3 What do we mean by Pre-Concentration Reduced load on downstream circuits Smaller DMS circuit = reduced maintenance Complementary technology to DMS IPJ acts as an additional feed preparation step prior to DMS and recovery Fines removed = improved downstream efficiency, reduced FeSi consumption Granite removed = reduced maintenance costs Clay and vegetation removed Transport costs from remote deposits Reduced capital and operating costs

4 Common Misconceptions Surrounding the IPJ The IPJ is no different to conventional jig technology The IPJ is too complicated to operate Diamond recoveries for the IPJ will never compare to that of a DMS circuit. The operating cost advantage for the IPJ is minimal when compared to DMS

5 MYTH 1: The IPJ is no different to Conventional Jig Technology

6 Thick Bed Separation Circular Configuration Low Velocity Cross Flow Reduces fines flow over to tails Saw Tooth Stroke High energy transfer to separation zone Moveable Sieve Particles accelerated from same starting point Low Interstitial Velocity Pressurized Enclosed & Lockable Why is the IPJ different? Effective Area Low footprint/capacity

7 MYTH 2: The IPJ is too Complicated to Operate

8 Typical DMS Flow Sheet

9 Typical IPJ Pre-Concentration Flow sheet 300t/hr Oversize 8mm Screen 75t/hr/IPJ 0.8mm Screen IPJ2400 IPJ2400 IPJ2400 IPJ2400 Tailings to Heap 225t/hr Tailings to Heap 75t/hr Conc to DMS

10 DMS Operational Risks and Controls Risk in DMS Ops Potential Consequence Control Holed screen panels Diamond loss Wear monitoring, daily samples Worn spigots Efficiency loss Wear monitoring Plugged sprays FeSi adhesion losses Operator checks, daily samples Fines in the feed Efficiency loss Daily samples Densifier inefficiences FeSi losses to effluent Daily samples Cyclone inefficiences Efficiency loss, diamond loss Tracer tests, density differential samples

11 IPJ Operational Risks and Controls Risk Potential Consequence Control Oversize in the feed Diamond loss Wear monitoring, daily samples, tracer tests Blown ragging bed Diamond loss Operator checks, monitor concentrate yield, maintenance inspections, tracer tests Erratic feed and operational control Diamond loss, reduced efficiency Instrumentation package, operator checks, tracer tests

12 Recent Upgrades to the InLine Pressure Jig Gravity feed the IPJ rather than pump feed Reduced maintenance requirements Lower operating cost Simplified design Increased availability Automation and Control system Increased availability Consistent operation Reduced operator input Remote Monitoring capability Tighter control on operating parameters leading to increased and consistent diamond recoveries. Fail safe operation

13 IPJ Gravity Feed Module

14 MYTH 3: Diamond Recoveries for the IPJ will never compare to that of a DMS Circuit

15 Williamson Tracer Test Work One IPJ2400 was retrofitted to ensure consistent IPJ feed rate and density 40 batch scale tests conducted using the retrofitted IPJ2400 Joint trial between Gekko, Williamson, and De Beers. Goals of the test work: To establish the applicability of IPJ technology to diamond tailings recovery To determine the optimum jig settings for continuous operation To identify and highlight potential risks in IPJ operation and how to effectively manage these

16 Williamson Test Work Highlights 12 mm, 8 mm, and 4 mm 3.5 s.g. tracers added to the feed for each test 100% recovery of 12 mm, 8 mm, and 4 mm 3.5 s.g. tracers for 12 of 40 tests, at concentrate yields between 7% and 13% Tracers recovered by Gekko supplied rare earth magnets Partition curves using 8 mm tracers produced for the final 22 tests Five variables tested: Ragging depth Stroke length Pulse rate Mass feed rate Volumetric feed rate Tracer Recovery Magnet

17 Angolan Alluvial Diamond Balance Testwork Processed the IPJ concentrate & tailings separately through DMS and recovery to determine a diamond recovery balance Treated 1320 tons of mm alluvial gravel through the an IPJ2400 Feed rate to the IPJ at 42 tph or 85 m 3 /hr Overall mass yield at 28% IPJ feed sample contained 2750 stones

18 Angolan Diamond Balance Results

19 Fine Kimberlite Application Pre-concentration of mm kimberlite tailings. Initial lab work yielded diamond recoveries of 100% for 2 mm tracers and 70% for 1 mm tracers into a 40% concentrate yield Best results from 3 month pilot plant trial showed: 96% recovery of 2 mm 3.5 s.g. tracers into a 25% concentrate mass. 100% recovery of 2 mm 3.5 s.g. tracers into a 50% concentrate mass 80 tph pre-concentration plant installed in Heavy liquid testing showed a recovery by value of 87% into a 31% mass yield.

20 MYTH 4: The Operating Cost Advantage for the IPJ is minimal compared to DMS

21 Economic Benefits of Pre-Concentration Without Pre-Concentration 200 tph DMS Plant $1 per ton* Operating Cost ($/day) $5,000 $4,000 $3,000 $2,000 $1,000 $0 With Pre-Concentration 200 tph IPJ Plant at $0.20 per ton** 50 tph DMS Plant at $0.93 per ton Overall operating cost of $0.43 per ton precon feed DMS IPJ *Estimated by Bateman **Actual Site Data

22 Operating Cost Differential Overall treatment plant operating cost reduction of at least 57% Installed power requirement reduced 85t/hr IPJ Plant: ~30kW Installed 100t/hr DMS Plant ~ Size and number of pumps reduced 85t/hr IPJ Plant ~ 2 pumps 100t/hr DMS Plant ~ FeSi Consumption reduced Due to smaller installed DMS Transport of FeSi to remote areas

23 Cost Benefits (Continued) Maintenance cost reduced dramatically Less Installed equipment Less pumping and wear components Labour Cost Reduced 85 t/hr IPJ requires 1-2 operators 100t/hr DMS Plant requires 2-4 Operators Capital costs of all downstream equipment reduced, typically 40-70% reduction Smaller DMS requirements Smaller Recovery due to better concentrate

24 Conclusions The InLine Pressure Jig IS very different to conventional jigging technologies The IPJ is less complicated to install and operate than other commonly used technologies Diamond Recoveries when operated properly are comparable with DMS plants Operating and Capital cost benefits of IPJ technology are considerable

25 Questions?