Catalytic Effects of Thiocarbonyl Reagents on Leaching of Synthetic Sulfides

Example 4

The catalytic effect of several other reagents having a thiocarbonyl functional group was examined on the leaching of synthetic chalcopyrite, covellite, bornite, and enargite. Experiments were carried out in stirred reactors containing 40 mM ferric sulfate solution at pH 1.8. 1 g of chalcopyrite or covellite was added to the reactors along with an initial concentration of 2 mM of various thiocarbonyl reagents including Tu, TA, SDDC, ETC and TSCA. The Cu extraction curves for chalcopyrite, covellite, bornite, and enargite using all or a subset of the above reagents are shown in FIGS. 20, 21, 22, and 23.

From FIGS. 20 to 23, it is clear that each of these further reagents that have a thiocarbonyl functional group show a beneficial effect in the ferric sulfate leaching of each of chalcopyrite, covellite, bornite and enargite.

FIG. 24 summarizes the results of further stirred reactor tests on chalcopyrite that additionally investigate urea and carbon disulfide. These results confirm that, as expected, neither urea nor carbon disulfide are effective reagents.