Влияние кучного выщелачивания золотосодержащего сырья на окружающую среду

Abstract

The issue of rational use of metal-containing raw materials goes hand in hand with the problem of minimization of environmental hazards caused by new technologies, which hampers the development of metal leaching, including gold leaching. The objective of this paper is the increase the mineral reserves of gold-mining enterprises via the application of leaching technology in stacks on the condition of minimization of damage to the natural environment. The results of the study of the impact of heap leaching complex on the surrounding ecosystems are provided based on the example of the stack of the «Kazakhaltyn» mine (the Republic of Kazakhstan), formed by tails of enrichment. The technological scheme of gold leaching and the parameters of its implementation, considering the minimization of consequences potentially hazardous for ecosystems, have been recommended. The calculation of parameters of hypothetically hazardous impact of gold leaching processes is provided for a stack of 6 m height; the time of leaching is 90 days; for four sorption stages, the coefficient of through-extraction of gold is 0.65. The specifics of the version of technology implying the use of recycled water supply to prevent contact with the environment are described. The processes of leaching affecting the environment and the preventive measures have been systematized. It has been demonstrated that emergencies are local, whereas sodium cyanide under the impact of atmospheric air and solar energy reacts with the generation of volatile short-lived hydrogen cyanide. It has been proved that the process of demetallization of mining and processing tails in the stack is a measure of environmental protection; it is not more hazardous than the traditional technology of handling processing tails. Such demetallization process is worth spreading.