Open AccessDeveloping a heap leaching technology for floating gold ores
Author(s) -
A E Vorobiev,
Tcharo Honore
Publication year - 2021
Publication title -
l.n. gumilev atyndaġy euraziâ u̇lttyk̦ universitetìnìn̦ habaršysy. tehnikalyk̦ ġylymdar ža̋ne tehnologiâlar seriâsy
Language(s) - English
Resource type - Journals
eISSN - 2663-1261
pISSN - 2616-7263
DOI - 10.32523/2616-7263-2021-134-1-20-29
Subject(s) - wetting , van der waals force , surface tension , buoyancy , colloidal gold , heap leaching , surface energy , nanotechnology , materials science , chemistry , leaching (pedology) , chemical physics , chemical engineering , metallurgy , nanoparticle , composite material , thermodynamics , geology , physics , organic chemistry , engineering , molecule , soil water , soil science , cyanide
The features of the technology of heap leaching with floating gold are disclosed. It was found that significant technological losses of gold in the processes of enrichment of gold-bearing ores, as a rule, are associated with its natural fine mineralization or technogenic transformation to such a state. It has been shown that flat gold flakes (even with a gold grain size of more than 1 mm) are quite well retained on the surface of technological solutions, i.e., have a certain buoyancy. The wettability of gold particles is explained by the manifestation of the surface tension forces of aqueous solutions, the mechanisms of which are determined by the van der Waals interaction. In addition, the wettability of gold grains is affected by their electric charge, which, accumulating on a convex surface, creates a negative charge that prevents the formation of a double electric field around the gold particle, which is an additional reason for the non-wettability of gold. The mechanism of the formation of gold films, which are formed at a high value of surface tension, with the formation of floating "islands" covered with a hydrophilic shell, is explained. It was revealed that the energy of interaction of a gold nanoparticle with water can serve as a quantitative indicator of the buoyancy of gold grains and "islands" of nanogold, at a value of which of 0.05427 eV, clearly pronounced hydrophilic properties appear. The theoretical substantiation of the buoyancy of gold grains and "islands" of nanogold is the van der Waals interaction. On this basis, heap leaching technology was developed, with the targeted deposition of floating gold in the most suitable places. As a result of a decrease in the surface tension of leaching solutions, nanogold loses their initial buoyancy and sink from them to the bottom, where they will be subjected to the processes of their disembarkation (collection and extraction).