Current trends of improving the efficiency of froth separation of diamond-bearing kimberlites

Abstract

Along with the introduction of new froth separation sections at new and existing enterprises, the basis for increasing the output of small diamonds is the reduction of their losses at the existing froth separation sections. The results of the studies of diamond surface composition under conditions of technogenic hydrophilization made it possible to establish the influence of the effects of crystallization of carbonate and silicate mineral films and the fixation of sludge fractions on the hydrophobicity and floatability of diamonds. It was proposed to use combined regimes of conditioning of ore and recycled water to increase floatability of diamonds, providing removal of hydrophilizing coatings and restoration of natural hydrophobicity of diamonds. The application of methods of acoustic, thermal, electrochemical, and reagent treatment of water-mineral disperse systems, as well as their combinations to increase floatability and reduce losses of hydrophilic diamonds in the process of froth separation was considered and substantiated. Based on the study of the effect of the temperature factor in the preparation and froth separation processes, the optimal temperature regime of froth separation cycle operations was substantiated, providing the use of the heat consumed for thermal treatment of the initial diamond-containing material at a temperature of 85–90°С to maintain the required temperature in the conditioning operations with a collector and immediately in the froth separation and flotation operations. It was shown that the regulation of phase composition of an apolar collector by additives of low- and medium- molecular fractions provides increase of its collecting ability due to transition of asphaltene-resin fraction into adhesion-active form and occurrence of processes of the collector autodispergating in aqueous phase. On the basis of the statistical analysis of froth separation process indicators depending on changing the share of recycled water in the processes the reason for worsening the indicators (performance) was determined, which consisted in a significant increase in the concentration of sludges. The optimum degree of recycled water use (85%) was determined, which ensures decreasing the used collector consumption by 8% without decreasing diamond recovery and concentrate quality.

Keywords

• diamonds
• kimberlites
• coatings
• conditioning
• hydrophobization
• collector
• froth separation
• closed-loop water recycling
• alrosa