The Formation of Crystalline Mineral Covers on the Surface of Diamonds and Their Destruction with the Use of Electrochemically Treated Water Products

Abstract

The composition of the surface of natural diamonds in interaction with minerals and the aqueous phase in the kimberlite deposit and processed ore are studied. The sequence and conditions for the formation of hydrophilic minerals on the surface of diamond crystals under conditions of processing of kimberlites have been determined. Confirmed the mechanism of hydrophilization of diamonds surface comprising formation of hydroxides and oxides of iron as a mandatory initial stage of crystallization. A method of restore the hydrophobicity of diamonds by the impact of electrolysis products of aqueous systems has been proposed, which allows to destruction or subsequent dissolution of minerals aggregate. The use of treated water in the process of froth separation it possible to increase diamonds recovery in the processing plant concentrate by 8.8%.

Intensification of diamond purification from hydrophilic minerals in foam separation process

“…The aqueous phase pH was measured by potentiometric method using Anion-410 analyzer. The foam separation process was studied at the enlarged laboratory-scale plant at the "Yakutniproalmaz" Institute [12].…”

“…Bench tests of the process of foam separation were carried out in the laboratory of the Institute "Yakutniproalmaz" at a pilot plant, which included sample preparation units, conditioning of recirculating water, agitation of ore with reagents and subsequent foam separation. At the first stage of the research, the composition of impurities on the surface of diamonds and the regularities of the processes of their formation were studied under the conditions of processing of refractory kimberlites [12].…”

“…Taking into account the findings of the present studies, testing of the products of the non-diaphragm electrolysis of recirculating water for removing the hydrophilic mineral formations from the diamond surface was performed. The recirculating water of the foam separation cycle accumulates various substances, including calcium and magnesium carbonate salts, which crystallize on the surface of diamonds and cause their technogenic hydrophilization [12].…”

“…The reason for the change in the hydrophobicity of diamonds is the cleaning of their surface in an aqueous medium that has passed the stage of electrochemical conditioning (Table 2). It was experimentally determined that the crystal surface, washed by the water electrolysis products, is characterised by low content of the impurity elements (< 5%) and oxygen content of less than 15% (Table 2) [12].…”

“…To evaluate the efficiency and select the best mode of thermal and electrochemical conditioning of recirculating water in order to give them the ability to activate the surface of diamonds in the conditions close to industrial, a series of experiments were conducted on the flotation of the studied diamond crystals in mineralized water and products of its nondiaphragm processing. Bench tests of the process of foam separation of the studied mineral objects were carried out in the laboratory of the Institute "Yakutniproalmaz" on a pilot plant [12], which included sample preparation units, conditioning of recirculating water, agitation of ore with reagents, and subsequent foam separation.…”