Mining Institute of the Kola Science Centre of the Russian Academy of Sciences, Apatity, Russia:

S. A. Alekseeva, Research Assistant, e-mail: alekseeva@goi.kolasc.net.ru
E. D. Rukhlenko, Chief Production Engineer

Apatity Branch of the Murmansk Arctic State University, Apatity, Russia:

S. V. Tereshchenko, Professor, Head of a Chair of Mining Engineering, Earth Sciences and Environmental Engineering
D. N. Pavlishina, Manager of Research Laboratory

A unique source of rare-metal and rare-earth elements is loparite ore, mining and processing of which are carried out at Lovozersky Mining and Processing Plant (MPP). The improvement of the enterprise’s processing figures has to do with an increase in recovery of fine-graded particles, losses with which amount to 60–70% of the plant’s overall loss. An increased load on the outmoded facilities and a low efficiency of slimes preparation to dressing are the causes of the losses such as these. The implemented investigations are based on the optimization principle, consisting in well-directed forming the products, characterized by homogeneity of the particles on some physical attribute, and timely removing them from the process. Proposed was a method of primary slimes separating from the feed at the 1st dressing stage by means of fine screening. An influence of slimes removal onto the indexes of spiral separation at the 1st dressing stage has been investigated. There has been shown a possibility of obtaining the final tailings with loparite content of about 0.1% at the yield up to 75% from the operation feed even at this stage. The granulometric characteristics of the screening product (feeding of a slime branch) as well as loparite distributuion and grains shape have been studied. The indicators achieved in dressing of this product according to a gravity scheme with the use of spiral sluices and table concentrators are 1.5–2 times higher than that of processing the plant slimes of current production. There has been developed a process flowsheet for primary slimes gravity processing, which comprise spiral separation at a sluice, cleaning of the obtained products on table concentrators and centrifugal concentrator. According to the proposed scheme, the expected loparite recovery into gravitation concentrate will be about 75% with loparite content not less than 51%. Overall loss with tailings will amount to 25% with loparite content of no more than 0.6%.

These investigations have been carried out in accordance with the Development program of the Federal state budgetary educational institution of higher education “Murmansk State Arctic University” and the Program of fundamental scientific research of state academies of science for 2013–2020 (Subsection 74 “The interior of the Earth integrated development and preservation, innovation processes of mineral deposits mining and minerals fine processing”).

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