Complex processing of the Artyomovsky mine dump

This work is part of a multiyear research of production of concentrates with fine-dispersed gold particles of 10-50 mm from the ore and waste rock dumps. Large and very large gold is extracted in Russia. However, the gold of 0.9-0.01 mm fraction makes up about 75% in the lithosphere. In primary ores gold is represented as particles smaller than 0.01 mm, and more than a half of the gold particles have a size of about 1-5 mm. This gold can be in the form of free particles and in the bound form with sulfides mostly. Clay deposits and weathering crusts basically contain subtle gold. As a rule the particles of gold are covered with a dense clay shell in these deposits. They do not lose their rigidity when wet as grains of other minerals. The gold particle in this shell is not easy to extract to the gravity concentrates and leach solutions. No more than 5% of gold particles with a size of 50 microns and less are extracted by modern gravitational methods and therefore it all goes to the mine refuse of factories. The weight of technogenic raw materials in the dumps of many mines is 5-15 million tons with the content of gold of 1-3 gr/t (sometimes more). These materials locate near highways and power transmission lines. They can become an object for processing if technologies for extraction of fine-dispersed gold are available. This article describes the process of production of a fine-dispersed gold concentrate from the Artyomovsky mine dump that contains wastes of gravity concentration of carbonate ores from the mine and weathering crusts with a high content of clay. The process consists of two stages. At the first stage 50% of the dump weight is dissolved in hydrochloric acid. CaCO3 and CaMg(CO₃)₂ make up 50% of this mass. The solution of Са02 and MgCl2 is a deicer. The remainder of the solid phase is treated by electrical discharges with the energy of 45-120 J (mkg/s). The clay components and, partially, minerals of associated rocks are crushed into particles of less than 45 microns in this process. The water flow directed upward and toward the flow of raw materials; it carries out the fine-dispersed particles of a certain size from the reactor, which is possible due to the water speed. Quartz and clay particles of less than 45 microns and gold particles of less than 10 microns are removed from the reactor with a cross section of 0.09 m2 at a 3.6 m/min flow rate of water, quartz particles of less than 200 microns and gold particles of 50 microns and less - at a flow rate of 89.2 m/min. Suspension moves to the deposition chamber of fine-dispersed gold in laminar conditions. The rate of sedimentation of identical particles of gold and quartz correlates as 14 : 1 in these conditions. The length of the deposition chamber does not exceed 2000 mm. Thus, a concentrate of fine-dispersed gold was obtained by using electroexplosive technologies and by moving fine-dispersed gold particles into the chamber in laminar deposition conditions.

Keywords

Authors

References