Recycling of Waste Slag Upon Production of Manganese Ferroalloys

The mineral resources base of manganese ores is sufficiently large in Russia. However, their mining capacity is almost absent. This is due to the low quality of domestic manganese ores and the high content of phosphorus. To date, Russia has been obliged to import the commercial manganese ore, manganese-containing ferroalloys, metallic manganese, and manganese dioxide. To produce the high-carbon ferromanganese the composition of charge was developed. The optimum variant was that where 10–15% of manganese-containing raw materials were changed for waste slag. In this case, the phosphorus content in the high-carbon ferromanganese is lower by approximately 20 rel. % in comparison with the production of ferromanganese only from the manganese-containing raw materials. About 50–60 rel. % of manganese can be extracted from the waste slag of silicon-thermal production. To produce the hot metal, the composition of iron-bearing burden material was developed. The optimum variant was that where 100% of manganese raw materials were changed for the waste slag. In this case, upon production of hot metal, the specific consumptions of manganese raw materials and limestone were decreased by 100 and 20%, respectively. The phosphorus concentration in metal was lower by about 10 rel. % as compared to the production of hot metal only from the manganese raw materials. Up to 55% of manganese can be extracted from the waste slag of silicothermic production, which is irretrievably lost at present. Keywords: manganese ferroalloys, manganese-containing raw materials, waste slag, hot metal