Scaled-up laboratory research into dry magnetic separation of the zhezdinsky concentrating mill tailings in Kazakhstan

Abstract

Purpose. Development of the rational technology for processing manganese-bearing tailings of the Zhezdinsky concentrating mill in the Republic of Kazakhstan aimed to obtaining manganese concentrate for smelting the silicomanganese. Methods. An integrated methodology of research is used in the work, which includes an analysis of modern scientific de-velopments and the experience of their use by mining-and-metallurgical enterprises. Experimental study of the tailings material composition has been made. A research scheme has been drawn up, including dry re-grinding of the mature tailings from concentrating mill with subsequent air classification, the products of which are beneficiated by means of dry magnetic separation in a separator with a constant strong magnetic field. Granulometric and fractional compositions of the feedstock and separation products have been studied. Findings. Based on the granulometric and fractional composition analysis of the Zhezdinsky concentrating mill mature tailings, it has been determined that the manganese minerals contained in them are very finely disseminated and belong to easily beneficiated materials. For a more complete recovery of manganese into the concentrate, dry re-grinding and air classification techniques have been included in the beneficiation scheme. Scaled-up laboratory research on tailings beneficiation has been conducted under the scheme: dry grinding to a grain-size of less than 1 mm, screening with division into classes of 0.5-1.0 mm and 0.0-0.5 mm, and then air classification. Air classification products are beneficiated using dry magnetic sepa-ration. It has been revealed that the use of air classification during the magnetic field induction of 0.5 T allows to increase the magnetic fractions yield by 7.5% and the manganese recovery by 9.42%. Analysis of the magnetic separation results of fine classes indicates the possibility of obtaining manganese concentrate with the required quality even without using the air classification. This greatly simplifies the beneficiation scheme for mature manganese-bearing tailings at the Zhezdinsky concentrating mill. Originality. It has been determined that dry re-grinding of the concentrating mill mature tailings to a grain-size of less than 1 mm, followed by air classification, makes it possible to fully disclose the manganese minerals. With subsequent dry magnetic separation this leads to an increase in the magnetic fraction yield and in the manganese recovery. Practical implications. The optimal technology development enables obtaining manganese concentrate with the required quality for the subsequent production of ferromanganese or silicomanganese during metallurgical treatment.