Student of the subdepartment of Non-Ferrous Metallurgy at ISTU, Philipp Zolotarev, suggests economical method of gold production from sulphide ores with the help of salt. Young scientist are working on a project jointly with the staff of the research institute "Irgiridmet." The development of the gold mining industry was considered as the best at the All-Russian concurs of National University of mineral resources "Gornyy".
As F. Zolotarev points out, the project aims at reducing the cost of gold production by accelerating the number of manufacturing processes. The student suggests achieving the goals by speeding up the process of extracting gold from refractory sulphide auriferous raw materials by means of salt.
"Nowadays there is almost no easily recoverable gold. Therefore, one of the problems for the gold industry is processing of ore and concentrates containing finely disseminated gold sulfides (mainly pyrite, arsenic and pyrite ores). The standard methods of its processing don’t allow extracting a big amount of the precious metal. It is usually applied the technology, providing autoclave oxidation followed by cyanidation. The laboratory experiments of standard process showed that the addition of halide ions, the source of which is salt, allows accelerating further process of the cyanide, "- said F. Zolotarev.
According to him, the standard cyanidation of cakes (product POX), the maximum concentration of gold in solution is achieved for 24 hours, while the addition of salt in the process POX, cyanidation reduces up to two hours.
"Studies have shown that the addition of halide ion dissolves gold and gold precipitates in a form favorable to cyanidation. In connection with this the total duration of the leaching also reduces the costs of reagent in the process of cyanidation and neutralization, which significantly affects the operational costs of mine development. "
In addition, the author of the project emphasizes that the addition of salt into the process chain affects another by-product of gold extracting - silver: "The main valuable component in the standard autoclave-cyanide circuit for processing of refractory gold-silver float concentrate is gold. Silver is not extracted, it proceeds to so-called jarosites. The experiments with halogen solvents showed that the recovery of silver in the material was increased from 20% to 80%. "
F. Zolotarev said that POX is one of the most promising areas of the gold mining industry overseas, the interest in this subject has also begun to emerge in Russia.
Young scientist plans to modify the technology and perform tests at the pilot plant.