Abstract:
This paper presents the results of laboratory studies for the distillation of mercury from
depleted coal sorbents produced in gold recovery factories using CIP technology. The mercury
content in these materials is more than 1%. The developed technology was tested in a large-scale
laboratory on a pilot vacuum sublimation electric furnace with the rheological movement of dispersed
material. The use of this equipment makes it possible to demercurize various materials with fairly
high moisture (up to 20%). It eliminates the use of an additional technological operation—drying the
material in a vacuum drying oven. It has been shown that a high degree of mercury distillation is
achieved (more than 99.8%) at 350–400 ◦C in the reaction space and residual pressure in the system
of less than 1.33 kPa, with residual mercury content in the material of less than 0.001% (10 mg/kg),
which complies with the European environmental standards. Mercury-free coal sorbents are sent
for combustion for the additional extraction of precious metal composites. The proposed vacuum
technology is characterized by its environmental safety because the process is performed in sealed
equipment, eliminating toxic emissions of mercury vapor into the atmosphere. The proposed vacuum
technology equipment is characterized by reliability and ease of use.
