AN OVERVIEW OF TAILINGS MANAGEMENT SYSTEM SELECTION

Transcription

1 AN OVERVIEW OF TAILINGS MANAGEMENT SYSTEM SELECTION

2 TAILINGS SYSTEM SELECTION OBJECTIVE: Provide Guidance Encourage Discussion Discuss Custom Assessment of Tailings Management Systems THE PRESENTATION: Focus on Wet-Wash Extractive Mines Overview of Tailings Management Technologies BENEFITS TO ATTENDEES: Broader view of what solutions are available for Tailings Management Improved understanding of the solutions are best used Perspective into the sorts of results achievable from each unit process Perspective into the Capital and Expenditure issues of each unit process Slide 2 of 17

3 PRESENTATION STRUCTURE 1. Tailings System Selection 2. Now and Then - Bridging the Gap: a) Thickeners b) Filter and Presses c) Alternative Methods d) Chemicals 3. Summary Slide 3 of 17

4 TAILINGS SYSTEM SELECTION In general, it costs more in the long run to NOT deal with tailings thoughtfully, from the beginning The right investment into the right Tailings Management System will maximise profit over the Life of the Mine Slide 4 of 17

5 TAILINGS SYSTEM SELECTION IN A NUTSHELL Current Situation (Profit 1) GAP Desired Situation (Profit 2) Several Solutions Best Solution Slide 5 of 17

6 BRIDGING THE GAP Every Mine is unique: Tailings-Site-Business combination There is a unique solution for every Mine Slide 6 of 17

7 BRIDGING THE GAP Capital and Equipment: Dams/voids/bunds/cells Tanks Mobile Equipment Loaders, trucks, screens, etc Conveyors Pumps Piping Mixers/Agitators Washery Equipment Thickeners and Clarifiers Filters and Presses Automation Chemical Equipment etc Slide 7 of 17

8 BRIDGING THE GAP Consumables: Power and Fuel Labour Chemicals Earthmoving Replacement parts Maintenance Technical support etc Slide 8 of 17

9 BRIDGING THE GAP SPECIFIC TOOLS Thickeners Filters and Presses (Dewatering) Alternative Unit Processes Chemical Additives Slide 9 of 17

10 THICKENERS TYPICALS Quarries typically 2-8% solids (w/w), depending on fine-sand Recovery Clean Process Water < 0.2% solids (w/w) Quarries typically 20-65% solids (w/w) Slide 10 of 17

11 THICKENERS The smarts : Rake selection and design Centre-well design Chemical program selection, design and support Poor selection and operation can: Decrease achievable underflow density Add to production downtime and reduced throughput Reduce the achievable thickener throughput Increase Opex requirements Slide 11 of 17

12 The use of settling and clarity aids (flocculants, coagulants): Critical to most modern thickener designs Reduce capital requirement/footprint Add robustness to operation Allows for a smaller water circuit Improved water quality THICKENERS Unit Area Flocculant Dose Slide 12 of 17

13 FILTERS AND PRESSES (DEWATERING) Mechanical Pressure: Plate and Frame Recessed Plate Belt-Press Filter Screw Press Disc Press Roll Press Tube Press Positive Fluid Pressure: Horizontal Plate Pressure Leaf Tubular Filters Centrifugal Discharge Slide 13 of 17

14 FILTERS AND PRESSES (DEWATERING) Negative Fluid Pressure (Vacuum): Rotary Drum Rotary Disc Horizontal Table Scroll Discharge Pan Filter Tilting Pan Filter Horizontal Belt-Filter Slide 14 of 17

15 ALTERNATIVE THICKENING AND DEWATERING PROCESSES Centrifugation Chemical-Only InLine Tailings Stacking Cyclonic Separation Slide 15 of 17

16 Chemical Treatment: Most filter/press applications benefit from some sort of chemical modification of the feed slurry Wide range of specialty chemical programs available Involve your chemical supplier in the Tailings System evaluation process FILTERS, PRESSES AND ALTERNATIVE METHODS Treated slurry on the gravity drainage zone of a belt-press application at a quarry Slide 16 of 17

17 FINAL SUMMARY A general rule: It takes a certain amount of something to do anything What you don t put in as capital, needs to be put in as consumables What you don t put in as consumables need to be put in as space and time Know where you are Know where you want to be and what it will mean to you There are many Tools to get you where you want to be Understand (quantify) the value of where you want to be Slide 17 of 17