Development and testing of a combined process based on the use of a flat-bottomed hydrocyclone and a multi-frequency screen

Abstract

The article provides a brief overview of the development of technology and equipment for the preparation of finely disseminated ores of ferrous and non-ferrous metals for further processing. Fine screening processes and equipment for crushed ores are considered, including in combination with centrifugal hydraulic classification. The purpose of the work was to improve hydraulic screening performance and efficiency for crushed ores. In order to optimize the preparation of finely disseminated ores for processing, a combined preliminary hydraulic classification process was developed for crushed ores based on the use of a flat-bottomed hydrocyclone and a multi-frequency screen. A pilot plant was used to test the process. The article contains qualitative and quantitative performance indicators for the hydraulic screening of crushed chromium ore with a particle size of 300–0 μm. The total recovery of all size classes below 300 μm into the undersize of the multi-frequency screen was 86.42 % and the recovery of finer ore classes (below 150 μm) was 91.09 to 92.97 %. The resulting combined process using a flat-bottomed hydrocyclone and a multi-frequency screen improves the total equipment performance, ensures high recoveries of fine classes into the undersize, extends the service life of fine sieves and reduces water consumption for oversize irrigation. This combined process is also recommended for use in hydraulic screening of magnetite concentrates at mining and processing plants in order to improve the iron content, as well as in closed fine grinding circuits in order to prevent overgrinding of valuable minerals and reduce the circulating load on the screens.