JSC “Institute Metallurgy and Ore Benefication”, Almaty, Kazakhstan:

S. A. Trebukhov, Deputy Chief Executive Officer, e-mail: vohubert@mail.ru
I. A. Marki, Leading Researcher
A. V. Nitsenko, Head of Laboratory of Vacuum Processes
A. A. Trebukhov, First Category Engineer

This paper shows the results of technological testings of vacuum-thermal demercuration of waste coal sorbents of gold mining enterprises on continuous vibro-vacuum unit VVU-1M (ВВУ-1М). We defined the volt-ampere and mechanical characteristics of vibro-vacuum unit operation, providing the uniform movement of waste coal sorbent by its shovel and truck method, and carried out the calibration of independent assemblies of unit's shovel and truck method. The enlarged technology testings were carried out on vibro-vacuum unit VVU-1Ms, using coal sorbents, containing 1.96% of mercury and 2.5% of moisture. Distribution of mercury by vacuum-thermal processing products is shown. During the vibro-liquefaction process, 99.95–99.98% of mercury was extracted in condensate for 5–7 minutes of material holding in furnace's isothermal zone in the temperature range of 350–400 ^oС and pressure range of 1.33–4.0 kPa. The unit design allows to reach the high rate of demercuration by combination of the basic parameters: temperature, pressure, time of material holding in reactor (productive capacity of equipment). The obtained sorbents with residual content of mercury (0.0005–0.0007%) can be send to further burning for traditional additional recovery of noble metals. According to this, the offered technology of preliminary vacuum-thermal removement of mercury from waste coal sorbents of gold mining factories allows to remove more than 99.9% of mercury from coal sorbent by ecologically-pure method and can be used in industrial scale at gold-mining enterprises.

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