In the flowsheets of gold-bearing ores concentration preparation air classifiers are used not only for separation of materials by size, but they are also used for preconcentration: extraction of coarse gold into the concentrate at the milling stage, extraction of fines with grading wastes into the tailings. As a result, there is no need to install massive gold separators and the quantity of material for concentration is lower.
The research works made with gold-quartz and gold-sulphide-quartz ores demonstrated that the use of centrifugal impact crushers makes it possible to increase the content of gold in ground products from 5% to 25% as compared to conventional crushers and mills, and there is less capital and operating expenditures.
A number of gold-bearing ore dry beneficiation investigations were conducted at several fields. As followed from the analysis of final products of dry concentration in Berezovskij field (