The dissertation is devoted to the solution of an important scientific and technical problem, which consists in physical and chemical substantiation, development and introduction in metallurgical production of a complex of rational technological schemes and decisions on attraction of materials of technogenic origin, accumulated and current production, including mining and metallurgical industry, using their useful properties in the processes of obtaining metals and alloys, the quality of which will correspond to those obtained by modern technologies, in order to reduce the use of imported raw materials, reduce through loss of conductive components, reduce fossil fuels and improve the environment of industrialized regions of Ukraine.
Analysis of physicochemical and rheological properties of oxide-granular concentrates of grade 2 fraction 0-1 mm shows that their characteristic sand-granular structure does not provide sufficient clumping of the charge, which does not allow to obtain the required particle size distribution and strength characteristics of granules. The possibility of returning 50…70% (against the usual 10…15%) of fine (0-1 mm fraction) manganese concentrate of the 2nd grade to the charge of manganese agglomerate production due to the use of peat hydroxide (RTG) reagent in an amount of 5…7% with simultaneous increase the strength of the granules of the pelletized charge.
For the first time, a method of creating appropriate thermal conditions was established and used in agglomeration, under which the cooling rate of the upper agglomerate layer is reduced, which is achieved by laying a two-component heat-insulating layer from the return fraction and fuel. This decreases the formation of glassy phase from 15% to 3%.
It is established on the basis of the analysis of mathematical modeling results that the rational carbon content in the initial charge of 9-11% provides the transition of manganese into the monoxide phase without the formation of a significant amount of manganese silicates, which reduces energy costs.
It is shown that in order to carry out effective dephosphorization of manganese alloys and achieve high degrees of phosphorus conversion into the slag phase, it is advisable to carry out the process of dephosphorization of the alloy in one stage using a briquetted mixture. This mixture includes iron scale, lime, bauxite and sodium orthosilicate, which due to the creation of slag with a melting point of 1400°C allowed to increase the rate coefficient of through extraction of manganese from raw materials.
Exclusion from the composition of materials for dephosphorization of fluoride compounds is an effective factor in increasing the level of environmental friendliness of the refining process.
Based on theoretical research, the involvement of iron ore mining in the production of cover rocks, which have a complex mineral structure and fine inclusions of iron oxides between silica, has been proposed and experimentally confirmed.
Developed recommendations for the technological scheme of high-temperature treatment of rocks with low-silicon ferrosilicon (15-18% Si) and electrochemical treatment with iron and hydrogen yield, which leads to the conversion of hematite into magnetite and extraction by magnetic separation.
Rational conditions are established of heat treatment of the initial slag-forming mixture containing dry lignin or other material of plant origin with a volatile content of 40-60% and dispersed CaO from cyclones of gas treatment plants, the ratio of which controls the degree of hydration of powdered lime not more than 50% and the process of spontaneous combustion of pyrolysis gases.
On the basis of theoretical generalization and results of physicochemical researches and thermodynamic modeling of the basic interactions created the through technological scheme of production of manganese ferroalloys with use of domestic manganese ores with low content of manganese and fine waste of enrichment for the purpose of stabilization of production of ferroalloys on JSC «Nikopol Ferroalloy Plant».
Implemented: scientifically substantiated resource-saving technology of manganese agglomerate production in the agglomeration of JSC "NZF" with the use in the charge of concentrate 2 grade fraction 0-1 mm to 100% with an assessment of the impact of this agglomerate on technical and economic indicators of ferrosilicon manganese smelting; technology of dephosphorization of the accompanying highly phosphorous manganese alloy, which is formed during the production of manganese low-phosphorus slag; recommendations for utilization of iron-containing sludge of PJSC MK Azovstal in obtaining metallized raw materials; new technological solutions for the involvement in the metallurgical production of materials of man-made origin are used in lecture courses and in the implementation of final qualification works of bachelors and masters OPP 136 Metallurgy of the National Metallurgical Academy of Ukraine.
