Por: Eng. Jorge Ganoza. Bear Creek Mining.

Introduction

Without any doubt, sodium cyanide is the best leaching reagent employed for extracting gold from different gold minerals. It’s well known that cyanide allows good gold extractions, it’s an economical reagent and can be neutralized to avoid environmental problems. However, the lack of amenable minerals and the concern for the environment have motivated the search for alternative reagents [1]. Probably, the first motivation is the psychological problem related to the use of cyanide in a new gold project.

No matter the existence of several gold operations around the world with detailed procedures respect to cyanide handling, some institution will make some observations to new gold projects, and mining companies will have to review the engineering design. The right procedures to handle cyanide try to reduce the impact of cyanide on the environment, but the necessity of new extractive projects is mandatory. Other reason to consider new leaching reagents for gold is based on the necessity to improve gold dissolution rate, and some reagents, such as thiourea, bromine, iodine, and thiosulphate, are interesting options. The application of new reagents has an impact on the metallurgy process, operating cost and capital investment.