Shuai Rao

Selection on the Process of Enriching Gold by Smelting from Refractory Gold Ores

To overcome the shortcomings of traditional cyanidation process for refractory gold ores, the smelting processes have been proposed. These smelting processes could be divided into two kinds, namely, indirect smelting and direct smelting. In the indirect smelting process, the calcine of refractory gold ores are added in the copper or lead smelting processes during which gold can be enriched into copper matte or crude lead. Then gold is extracted from the anode slimes. In the direct smelting process, refractory gold ores are smelted directly with gold enriched into ferrous matte. Then gold is extracted from ferrous matte. Based on the direct smelting process, the metallurgy-beneficiation united process for refractory gold ores has been proposed. In this process, gold is firstly enriched into ferrous matte by direct smelting, then the grinding-flotation process is used to obtain gold-rich sulfurous iron ore, and finally gold is extracted via hydrometallurgical method. The metallurgy-beneficiation united process has advantages of high gold recovery ratio, environment-friendly and low cost, which provides a new idea for the extraction of gold from refractory gold ores.

Selection on the Process for Removing and Recovering Antimony from Antimonial Refractory Gold Ores

It is well known that the gold ores containing a high content of arsenic and antimony are very refractory. In this paper, the adverse effect of antimony on the extraction of gold by pretreatment-cyanide leaching was discussed in detail. Moreover, these processes of removing and recovering antimony from alkaline sodium sulfide or hydrochloric acid systems were introduced. Last but not the least, a novel cleaning technology for recovering antimony from refractory gold ores was proposed. Antimony was dissolved into the solution with sodium sulfide and sodium hydroxide as leaching agents. And then pressure oxidation technology was applied to prepare sodium pyroantimonate from sodium thioantimonite solutions. This process is more promising owing to its high removal ratio of antimony, low production cost and environment friendly, which provides a positive guidance for the extraction of antimony from antimonial refractory gold ores.

Ligand Selection Model for Leaching of Low Grade Zinc Oxide Ores

A new ligand selection model is proposed for leaching of low grade zinc oxide ores. The model demonstrates that the formation constant between ligand and zinc ions plays a significant role in the leaching process. A series of leaching experiments with different ligand concentration are conducted to assess the selection model. The results show that when nitrilotriacetic acid is used as the leaching agent, the highest zinc extraction is obtained. The zinc leaching rate is 84.33% in the presence of 0.4 mol/L nitrilotriacetic acid and liquid-solid ratio of 10 mL/g.