PHYSICOCHEMICAL AND ELECTROCHEMICAL METHODS FOR MODIFYING THE PROPERTIES OF DIAMONDS AND ORE PULP COMPONENTS DURING THE SEPARATION OF DIAMOND-BEARING KIMBERLITES

The main deposits of kimberlite ores located in the regions of Western Yakutia are enriched at the ALROSA diamond extraction factories using a similar technology, in which the maximum completeness of extraction and safety of diamond crystals is ensured by the stages of schemes. The bulk of diamond crystals is extracted in the processes of heavy medium, sticky and foam separation, the effectiveness of which is determined by the properties of diamonds, kimberlite minerals and the media separating them. The article presents the results of theoretical and experimental studies carried out by ICEMR RAS together with the largest universities in Russia, scientific and industrial enterprises of ALROSA. It is shown that the use of combined energy methods of destruction and removal of hydrophilizing formations on diamond crystals provides hydrophobization of their surface in the processes of sticky and foam separation. It has been established that the efficiency and economic indicators of the process of dense medium separation of diamond-containing raw materials are due to the stability of the technological properties of the weighting agent of the ferrosilicon medium and the suspension prepared on its basis. The method for modifying the corrosion resistance of ferrosilicon by nitriding its surface has been substantiated and tested. The proposed method makes it possible to create a protective shell on the surface of the granules, preventing their destruction upon contact with corrosive components of the water-air environment. Semi-industrial tests have established the possibility of increasing the extraction of diamonds into concentrates for sticky and foam separation by 4 and 5.2%, respectively. The results of laboratory tests have confirmed the possibility of reducing the corrosion rate of ferrosilicon by 5-6 times in the process of dense medium separation.