Ural State Mining University, Ekaterinburg, Russia:

Kozin V. Z., Head of Chair, Doctor of Engineering Sciences, Professor, gmf.dek@ursmu.ru
Komlev A. S., Engineer, Candidate of Engineering Sciences, tails2002@inbox.ru
Volkov P. S., Engineer, tails2002@inbox.ru

Preparation of samples containing uncrushable material inclusions, with respect to material size, required for analysis, fails. In order to provide for acceptable margin of analytical error, uncrushable inclusions are proposed to be separated into individual product with subsequent individual analysis of crushable and uncrushable parts of sample. With that, error of sample analysis result on the whole decreases, with increase of separated uncrushable part of sample. Theoretically, it is shown that from the two alternative methods of uncrushable sample part separation (by means of sieves or centrifugal concentrators) the latter is preferable. When this equipment is used, analytical error margin is decreased even with small separation of uncrushable inclusions, which, as a rule, are of largest size, while sample itself may be high-mass. Experimental validation was performed on reference material — quartz of size d_{max 0} = 1 mm with uncrushable inclusions as metal lead of the same size. Sample mass – 6.4 kg. In analysis of weighed portions of 50 g mass with same uncrushable inclusions, relative analytical error was 36.8 %. Following lead part by weight equal to 0.517 was separated on centrifugal concentrator, and subsequent tailings analysis with same weighed portions, error decreased to 9.77 %. To remove uncrushable native metals from samples, it is expedient to use self-cleaning centrifugal concentrator with internal turbulization K-200VL and mechanical sample dividers MP-02RS and SOD-2-100 (by «Tails Co.»). The equipment in question permits to assemble laboratory concentrating and sample-dividing modules.

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