The hydrometallurgical application of thiourea in processing precious metal ores and concentrates has reached the development stage. This paper reviews recent technical literature covering the process development of thiourea leaching. In addition, recent fundamental contributions are discussed. Most of the interest in thiourea leaching has involved treating high grade concentrates that have sufficient value to justify the use of thiourea as a reagent. An important development in thiourea technology is the addition of SO//2 to the leaching solution. This procedure effectively reduces the decomposition of thiourea and eliminates the problems of passive surface layers that limit the leaching efficiency. Results for the thiourea leaching of a bulk sulfide concentrate and a residue from the autoclave leaching of a smelter flue dust are also reported.
ASJC Scopus subject areas
- Control and Systems Engineering
- Geotechnical Engineering and Engineering Geology
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry