Leading Research Institute of Chemical Technology, Moscow, Russia:

V. A. Tolkachev, Leading Researcher, Candidate of Engineering Sciences
N. P. Paskhin, Senior Researcher
D. V. Mainikov, Senior Researcher, didima06@mail.ru

In hydrometallurgy of uranium as well as nonferrous and rare metals, pulp slurry fed from processing to leaching circuit is recommended to densify in order to remove extra water and to diminish the size of charge stock. Dewatering processes are conventionally carried out in hydrocyclones and radial thickeners intended for sedimentation of solid particles under action of centrifugal forces and gravity, respectively. For high productivity of modern mining-and-processing and metallurgical plants, thickeners to 50 m in diameter are available. A plant needs several such thickeners to provide total project capacity. Being large, such equipment is arranged in the open air; however, the outdoor installation and operation of the machines in the conditions of extremely low temperatures in the areas of the Far North, Far East of Russia, etc. is dramatically problematic. Moreover, under low temperatures, efficiency of flocculating agents added in pulp slurry to accelerate precipitation of solids drastically decreases. Experts of the Leading Research Institute of Chemical Technology propose densifying pulp slurry using cyclones and thickening plates dimensions of which allow installation in the enclosed and heated areas. In the course of lab-scale research and full-scale tests, it was undertaken to separate initial pulp slurry with a density of 1200 kg/m³ in a cyclone, the discharge was fed to a thickening plate, added with a flocculant and densified to a density of 1250–1280 kg/m³. After mixture with cyclone sands, the pulp slurry density became 1510–1530 kg/m³. Such pulp slurry can be watered down to any density value before leaching.

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