Ammosov North-Eastern Federal University, Yakutsk, Russia:

P. P. Sharin, Head of a Chair, Candidate of Physico-Mathematical Sciences, psharin1960@mail.ru
M. P. Lebedev, Head of a Chair, Doctor of Engineering Sciences, Corresponding Member of the Russian Academy of Sciences

Yakutniproalmaz Institute, Mirny, Russia:
G. M. Nikitin, Deputy Director of Innovation – Head of the Center for Innovation and Technology

Larionov Institute of Physico-Technical Problems of the North, Siberian Branch, Russian Academy of Sciences:
G. G. Vinokurov, Leading Researcher, Candidate of Engineering Sciences

This research aims to develop a thermal-adhesion method of automated extraction of diamond grains from kimberlite concentrate after X-ray fluorescent separation. The method is based on the very large difference between thermal conductivities of diamonds and associate minerals in concentrates. A pilot plant has been designed to examine production processes of thermal-adhesion picking and extraction of diamond grains from kimberlite ore concentrate. Based on the analysis of strength of contact between thermal-adhesive substances and diamonds, it is recommended to use pure colophony as the thermal-adhesive substance. High selectivity and efficiency of the developed method for thermal-adhesion picking and extraction of diamond grains has experimentally been proved. It is found that diamond grains securely stick to colophony layer applied to special launders on the surface of conveyor belt. Extraction capacity per one launder of the pilot plant makes 18 000–36 000 grains/hour. Based on the experimental research, the pilot plant process variables are developed as: heater-roller temperature 150–350 ºС; colophony layer thickness 0.5–0.9 mm; conveyor belt velocity 30–100 mm/s. The developed method of thermal-adhesion extraction of diamonds from concentrates is secured by the patent of the Russian Federation.

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18. A. M. Timofeev, P. P. Sharin, M. P. Lebedev, R. G. Nogovitsyn. Method of separation of diamond-bearing mixtures of minerals. Patent RF, No. 2546702. Published: 10.04.2015. Bulletin No. 10.