Browsing by Author "Van Wyk, A. P."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Gold CIP and CIL process optimization in a capital constraint environment
    (The Southern African Institute of Mining and Metallurgy, 2017-05) Snyders, C. A.; Akdogan, G.; Bradshaw, S. M.; Van Wyk, A. P.
    ENGLISH ABSTRACT: This article focuses on the use of a model in combination with economic analysis to extract maximum value out of current gold operations, without the need for additional capital. Two South African case studies (CIP and CIL) are presented to show that an optimum point of operation exists. This optimum point of operation, however, depends on several economic factors such as the gold price, exchange rate, and utility costs in combination with plant conditions such as the feed rate and Au grade. As these parameters fluctuate, the operating conditions will have to be adjusted to achieve the maximum value. Operating at a maximum will require regular decisionmaking and adjusting of operating conditions, especially in times of a constrained economy.
  • Thumbnail Image
    Item
    Investigating the behaviour of PGEs during first-stage leaching of a Ni-Fe-Cu-S converter matte
    (Southern African Institute of Mining and Metallurgy, 2018) Snyders, C. A.; Akdogan, G.; Thompson, G.; Bradshaw, S. M.; Van Wyk, A. P.
    ENGLISH ABSTRACT: In a first-stage atmospheric leach in a Sherritt Ni-Cu matte leach process, a Ni-Cu-Fe-S Peirce-Smith converter matte is contacted with recycled aqueous copper sulphate/sulphuric acid solution (spent solution) with the purpose of dissolving nickel, while simultaneously removing copper (via metathesis and cementation reactions) from solution. While the iron content has been found to have a significant impact on the first-stage leach, a previously expected relationship between copper and PGM behaviour has not been established clearly. For this study, a converter matte consisting mainly of heazlewoodite (Ni3S2), chalcocite (Cu2S), and awaruite (Ni3Fe) was leached in a laboratory-scale batch reactor. The temperature, acid, and copper concentration under both oxidative and non-oxidative conditions were varied, while the copper, iron, and PGEs were tracked and the pH and Eh measured. Palladium was generally found to be closely related to the behaviour of copper, while platinum did not leach. The other platinum group metals such as iridium and rhodium were found to precipitate only with accelerated precipitation being observed during Fe precipitation reactions.