Dearsenation of Gold-Bearing Composite Concentrates without Forced Displacement in a Sublimator

Abstract

The primary devices for extracting volatile components from dispersed materials in a vacuum are devices with the movement of raw materials by directed vibrations. During the analysis of the operation of such installations, some shortcomings were identified, due to the supply of heat flow to the processed raw material and the requirements for the choice of structural materials. In this article, the authors tested a heating method and a design of a sublimator with the supply of heat flow to the dispersed material by radiation from the heater. The sublimation zone is made in the form of a shaft formed by simple-shaped plates, the design and material of which involve the use of refractory and ceramic materials that are inert with respect to an aggressive vaporous sulfide medium. The movement of bulk material through the volume of the sublimator occurs due to rheological properties: sliding along inclined plates. Technological tests on the sublimation of arsenic sulfides from gravity and flotation composite concentrates of the Bakyrchik deposit (Kazakhstan) have shown the possibility of a high degree of sublimation of arsenic (more than 96–99%) while preserving precious metal composites in the sublimation residue and stable operation of equipment. Sublimation residues containing 0.14–0.30% As can be processed by known methods. The possibility of sufficiently complete removal of arsenic and its compounds from composite concentrates at a reduced pressure with the removal of the latter in the most environmentally friendly sulfide form has been established.