1 / 25

Soluble Metal Recovery Improvement Using High Density Thickeners in a CCD Circuit Ruashi II a Case Study

Soluble Metal Recovery Improvement Using High Density Thickeners in a CCD Circuit Ruashi II a Case Study. February 2009 M. Mulligan (Presenter) L. Bradford. Agenda. Introduction Thickener technologies Lab Simulations CCD Simulations High Density vs High Rate Thickeners. Introduction.

lave
Download Presentation

Soluble Metal Recovery Improvement Using High Density Thickeners in a CCD Circuit Ruashi II a Case Study

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Soluble Metal Recovery Improvement Using High Density Thickeners in a CCD Circuit Ruashi II a Case Study February 2009 M. Mulligan (Presenter) L. Bradford

  2. Agenda • Introduction • Thickener technologies • Lab Simulations • CCD Simulations • High Density vs High Rate Thickeners

  3. Introduction • Ruashi is a Copper/Cobalt mine in the DRC • Circuit overview: Leach-CCD-SX-EW • Copper recovery is critical in the CCD circuit • Lab & CCD simulations to optimise recovery • Selection and design of the best thickener technology

  4. Thickener Development Conventional High Rate – flocc + dilution High density – flocc + dilution + compression Paste – flocc + dilution + compression + residence time

  5. Different Thickener Technologies

  6. Counter Current Decantation (CCD)

  7. Lab Simulations

  8. Lab Simulations • Sedimentation testwork done within hours of the leach done at Mintek • Settling & flocculant flux curves • 4 litre batch tests • 4 litre continuous tests • Rheology

  9. Optimal % Solids for Settling Optimum = 7% – 8%

  10. Optimal Flocculant Dosage Optimum = 50g/t

  11. Underflow % Solids vs Time Batch: 55% Continuous: 59%

  12. Rheology • Haake Viscometer • Measure yield stress of thickener u/flow • Info used to size rake drive

  13. Rheology 60 Pa at 59% Solids

  14. CCD Simulations

  15. CCD Simulations Variables used in base case simulation

  16. CCD Wash Recovery

  17. Sensitivity to Wash Ratio

  18. Sensitivity to Underflow % Solids

  19. Counter Current Decantation (CCD) U/f % Solids: 59% Wash Ratio: 1.6 RECOVERY: > 99%

  20. High Density vs High Rate

  21. High Density vs High Rate Thickeners CCD wash recovery • HD always has higher wash recovery per stage for a given wash ratio Capital cost implications • Per thickener cost is similar – HD diameter smaller • Overall CCD plant costs less with HD – less stages required

  22. Increase in Income Based on 5 stages. Wash ratio = 1.6

  23. Thickener Design Differences • Higher tank sidewall depth • Steeper tank floor slope • Higher rake mechanism torque • Rake mechanism – Pickets • Thickener discharge cylinder

  24. Conclusions • Lab simulations & CCD simulations are important for decision making and design of a CCD plant • 5 High Density thickeners give a better recovery than 6 High Rate thickeners for Ruashi • Capex and Opex costs both lower with High Density thickeners at Ruashi

  25. Questions ???

More Related