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

The Waste of the Ferroalloy Production in Russia

Ferroalloys are used to change the composition and properties of ferrous and non- ferrous metals. Therefore, the volume of ferroalloy smelting corresponds to the amount of steel and other alloys produced. Currently world steel production is approximately 1630 million tons, and about 40 million tons of various ferroalloys are produced (2.5%). The structure of ferroalloy production in different countries mainly depends not on the needs of industrial enterprises, but on ore reserves. Excessive amounts of ferroalloys produced are exported, and the missing alloys are imported. In Russia silicon alloys that have no restrictions in the raw material base (44%) are the most produced, then manganese (25%) and chromium (23%) ferroalloys. The remaining ferroalloys account for 8% of production. About half of the manganese ferroalloys needed for consumption are bought abroad, and half are produced in the Russian Federation from foreign raw materials (Kazakhstan, South Africa, Gabon). The Russian Federation provides itself with chromium ferroalloys completely, and sells ∼ 80%, and for their production mainly imported raw materials (∼ 65%) from Kazakhstan are used. Keywords: ferroalloy, ferrochrome, slags, production of ferroalloy

Problem of manganese in Russian metallurgy

Ferrous metallurgical industry is the main consumer of m nese. The production volume of manganese ferroalloys in the world is approximately 1 % of steel production. After the collapse of the Soviet Union, Russian Federation found itself without any manganese ore base. At present, only high-carbon ferromanganese and ferrosilicomanganese are smelted from imported ore in Russia in a limited quantity. The mineral and raw base of manganese ores in Russia is quite large: the balance reserves of manganese ores are about 230 million tons (approximately 2 % of the world), forecast resources – more than 1 billion tons. Quality of the manganese ores is lower than the manganese ores of most major producing countries. Average manganese content in Russian ores is 9 – 23 %. Basis of mineral and raw base of these manganese ores are carbonate ores, share of which is more than 77 %. Manganese ore mining in Russia is sporadic and does not exceed 66 thousand tons per year. Demand of Russian ferroalloy plants, producing manganese ferroalloys, in manganese ores and concentrates is covered by imports. The problem of accelerating the creation of domestic manganese ore base from the position of economic security seems to be very important. It is necessary to solve a number of issues related to the enrichment of poor manganese ores, development of effective technologies for manganese ferroalloys smelting from concentrates obtained after the enrichment of these ores, as well as creation of more advanced methods of manganese concentrates dephosphorization. In the production of manganese ferroalloys from ore to finished alloys, about 50 % of manganese mined from the subsoil is lost; a large number of by-products are formed (sludges of enrichment, slags, screenings of small fractions of ore raw materials and finished products, sludges of smelting process and dust). The use and processing of them allow not only to reduce the consumption of initial mineral raw materials, but also to increase the efficiency of main production and to reduce environmental pollution. Additional extraction of manganese from industrial wastes and improvement of the technological processes for manganese ferroalloys smelting are the ways to increase the through extraction of manganese.

Physical and chemical bases of decarburization of high-carbon ferromanganese melt

The aim of the work is to establish physicochemical patterns of behavior of carbon, silicon, manganese when using the method of oxygen purge of high-carbon ferromanganese. Method. The process of blowing red metal to sour is neglected. With the fusion of fused acid, it is more important to oxidize silicon. Its presence in metal is practical in the block of oxidized manganese. Because oxygen is an assimilation gas, the mixing processes of the converter bath components and the reduction of manganese oxides at the metal-slag interface do not develop properly during purging. The smelters of the medium-carbonaceous ferromanganese in the converter are characterized by a stable chemical warehouse and even a higher number of vimogs for this type of alloy. The low concentration of silicon in metal over a number of swimming trunks can be easily shoved with a hat of pre-purge bathtub with sour at the final stage of refining. The behavior of phosphorus in these smelts is not controlled. The content of P2O5 in the final slag is 0.1%. To achieve acceptable concentrations of phosphorus in the metal, it is necessary to use starting materials with a low phosphorus content. Scientific novelty.Taking into consideration the high affinity of silicon for oxygen, the physical and chemical basis for the production of medium-carbon ferromanganese, as well as metallic manganese and low-carbon ferromanganese, is the process of the interaction of manganese oxides of a certain basicity slag melt with silicon dissolved in ferromanganese (manganese), that is, as combined reduction -refining process to produce manganese ferroalloys with a given silicon content standard

Manganese Ferroalloys of Russia

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Steel Micro-alloying with Boron: A Perspective Direction to Reduce the Consumption of Manganese Ferroalloys

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