Andreev Ye. Ye., Associate Professor, opi-opi@bk.ru; Lvov V. V., Associate Professor, opilvv@mail.ru; Tikhonov N. O., Student; Saint-Petersburg State Mining University (Russia).

Effects of principal differences of most frequently used mineral particles mechanical mixtures' particle-size distribution determination methods, like sieve analysis, classification in hydrocyclones bank, laser classification, have been studied with regard to the results, obtained by these methods. –212 microns fine quartz sample size analysis data, obtained by means of the three above-listed methods, have been tabulated and presented in graphic form. Effect of mechanical mixture particles geometric shape upon particle-size distribution characteristics, obtained for the mixture in question, has been considered. A factor for mineral particles shape conversion is proposed, permitting to combine analyses' results, obtained by different methods, into a uniform grain-size analysis characteristic for particles mixture. A simplest example of its practical application is presented. The performed analysis and proposed mineral particles shape conversion factor permit to increase particle-size distribution results reliability with respect to different products. This is especially effective with regard to ore-preparation circuits, where controlled products are related to one processing flow sheet. For example, for wet grinding in closed circuit, where particle-size distribution estimates in starting feed, mill discharge, classifier overflow and sands in circuit's end, are obtained by different methods of dry and wet sieve and slime analyses, the latter results, regarding subsequent use, require obligatory bringing to one format (especially when these data are used as starting information in prediction and optimization computer packages).

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