PROCESSING OF MANGANESE-CONTAINING WASTES TO PRODUCE MANGANESE PELLETS FOR FERROALLOY PRODUCTION

Abstract

At various stages of processing manganese ores, significant volumes of finely dispersed manganese-containing raw materials are formed. Development of technological solutions is required for their use in metallurgical processes. The aim of the study was to develop technologies intended to beneficiate manganesecontaining sludge with the fraction of less than 5 mm and to obtain pellets suitable to be melted into ferromanganese on their basis. The developed beneficiation process flow for manganese sludge includes the screening processes into size classes: - 2.5+1.25; - 1.25 +0.071 and -0.071 + 0 mm, beneficiation in jigging machines of - 2.5+1.25; - 1.25 +0.071 mm classes and concentration on the table of -0.071 + 0 mm to get manganese concentrate containing 29.17 % Mn. The combined manganese concentrate was further subjected to dry magnetic separation that increased the Mn content to 35.2 %. Manganese-containing pellets were obtained using a high-speed mixer-granulator manufactured by Eirich. Technological parameters were determined for the pellet production based on the composition consisting of manganese concentrate, small fractions of special coke, ferrous forms of diatomite and lime. It was found that manganese was present in the composition of pellets burned at 1170oC in the form of jacobsite MnFe2O4 and hausmannite Mn3O4. The ferrobustamite (Ca0.79Fe0.21)SiO3 phase was also formed, which contributes to an increase the strength of the products. Compressive strength of the obtained pellets was 33.7 kg/pellet. Melting temperature of annealed pellets was 1200��. The obtained pellets were suitable to melt ferromanganese alloys.