Ruban A. The improvement of the method of silicomanganese production in ore-smelting electric furnaces based on scientific analysis of burden content aimed to increase the output of commodity product

The research study presents the ways of improving the method of silicomanganese production that positively affects both performance indicators and the output of commodity product. That is the first time when temperature range of system equilibrium state has been calculated while using the model of manganese carbosilicium phase formation along with carbon thermal reduction of manganese and silicium oxides. The nature of relationship between the silicon content in metal and process temperature, silica concentration and basicity was first determined. It was proved that such relationship as [Si,%] = f (CaO + MnO) / SiO2 can identify the silicon content within wide temperature range with high probability. Quantitative relationship between carbon and silicon content in Mn-Si-C system alloys was measured. This contributes to the prediction of carbon content in industrial ferrosilicomanganese (15-20% Si), which is 2,2% - 1,5% at 1550 °C and 2,6% - 1,8% at 1600°C. As an innovative contribution this allows to determine both temperature ranges of the process and carbon content based on silicon content in the melt with maximum accuracy. Carbon-silicide phase Mn8Si2C was first identified in industrial silicomanganese alloy by means of X-ray phase analysis. Phases Mn5Si3, Mn4FeSi3 and (Mn1-xFex)5Si3 with different Fe content were determined for the first time. Microhardness of silicomanganese phases with different Fe content was tested. It was found out that the alloys with higher Fe content produced using the suggested method are stronger. As a result, it increases the output of consumable product. Manganese charge slag with the dominant bustamite (Ca,Mn)2SiO4 phase and identified Mn3Al(SiO4)3, Ca7Mg(SiO4)4, CaMg[SiO4] and MnS phases were analyzed by means of X-ray phase analysis for the first time. The process of silicomanganese production with high-carbon silicomanganese non-fraction alloy as a burden instead of oxide burden components with manganese content was first developed and tested in a laboratory environment. Hereinafter, up to 58% of silicon can be extracted out of quartzite. The process of silicomanganese production with higher Fe content has been analyzed and tested at the Nikopol Ferroalloy Plant PJSC. Electric power consumption was reduced by 3-5% and slag ratio was reduced by 0.2 that increased the output of consumable product. The feasibility and commercial efficiency of the suggested approaches were proved due to the increase in silicon extraction using high-carbon ferromanganese non-fraction alloys while following the developed method instead of oxide manganese ore material. The financial effect of high-ferrum alloy production in the amount of 10% of total annual output allows to save 6,054,750 UAH on account of reduction of specific power consumption.