Prognostical assessment of technological indicators of ferruginous quartzites enrichment

Abstract

ntroduction. When developing a technology for the enrichment of mineral raw materials, reliable information about its material composition and a qualified technological interpretation of the data obtained is important which allows us to pre-evaluate the possibility of obtaining enrichment products of the required quality. The quality of raw materials to produce metallized pellets (DRI) and hot-briquetted iron (HBI) has high requirements for the content of iron, silica, and other impurities. For Mikhailovsky GOK named after A.V. Varicheva (MGOKa) the priority task is to develop a technology for the isolation of high-quality magnetite concentrates with a reduced content of impurities to produce DRI pellets. The purpose of the work. Using the example of the material of the over-latticed product of wet thin screening, we propose a methodological approach and develop an algorithm for preliminary evaluation of the possibility of obtaining magnetite concentrates of improved quality from iron ore concentrates of the MGOC and substantiate the maximum possible technological indicators of the process of enrichment. Research methodology. Fritch’s Analizette 22 laser analyzer, ECLIPSE LV100-POL polarizing microscope, SMZ-1500 optical stereomicroscope equipped with DS-5M-L1 digital micro-photographic system and MLA 650 (FEI Company) automated mineralogical analysis tool complex was used to study. The data array was processed using standard MLA software, as well as personal algorithms, in an Excel environment, taking into account expert knowledge on enrichment technology. Amines were used for the reverse flotation of the crushed super lattice product. The content of elements in the samples was determined by X-ray fluorescence analysis. Research results. A methodological approach to the predictive assessment of technological indicators of ore enrichment is proposed, which allows, based on the study of a statistically representative number of particles of the source material and expert technological knowledge, to calculate the mineral, elemental composition, the maximum possible quality and extraction of valuable components and impurities into the concentrate. On the example of the over-lattice product of fine screening of an ordinary concentrate of magnetic separation of nonoxidized ferruginous quartzites of the Mikhailovsky GOK named after A.V. Varichev developed an algorithm for predictive evaluation of technological indicators enrichment, which consists in processing information about the mass fraction of each particle among the statistically reliable number of counted particles, its equivalent diameter, the mass fraction of all minerals and elements included in the particle, as well as the fraction of the particle surface represented by each of the minerals and a number of other parameters using standard MLA software, as well as its own algorithms, in the Excel environment, taking into account expert knowledge on enrichment technology. Additional processing of information in the Excel environment involves ranking and sampling of particles by quality, as well as sampling by size, mineral and elemental composition. The ranking is carried out according to three options: in descending order of the content of magnetite, the total content of magnetite, hematite, and carbonates, as well as the total content of magnetite, hematite, carbonates and aegirine. The ordered database obtained as a result of particle ranking is used for virtual accumulation of the calculated concentrate. Virtual accumulation was carried out by attaching to the calculated concentrate of all particles sequentially, one by one, from an ordered database: from the first with the maximum quality to the last with the minimum. Since for each particle its yield (mass fraction) of all the particles in the database is known, as well as the mass fractions of elements and minerals, the yield, content and extraction of all components can also be calculated for the accumulated concentrate as the particles are added. Thus, as a result, the enrichment characteristics can be established, linking the content of the component selected as a criterion for the quality of particles with its extraction into the concentrate, as well as with the yield of the concentrate, the content and extraction of the remaining controlled components into it. The results of the calculations make it possible to build the enrichment curves of the material by minerals and elements. Resume. The possibility of obtaining from a thin-screen product of fine screening of ordinary magnetic separation concentrate the MGOK, magnetite concentrates the quality of which meets the requirements of the production of DRI pellets has been established: the maximum theoretically achievable quality of magnetite magnetite concentrate is 71.90 % Fe, 1.04 % SiO2, 0.019 % K2O when the concentrate is 53.7 % and Fe is extracted into it. 60,00 %. Taking into account mechanical losses and a variant of the mineral composition of the final magnetite concentrate: in the absence of aegirine, the maximum theoretically achievable quality will be 70.94 % of total iron, silica – up to 1.50 %, potassium oxide – 0.04 %, sodium oxide is absent. At the same time, iron extraction is reduced to 60.58 %. If aegirine passes into the concentrate, the maximum achievable quality of the concentrate is 70.88 % iron, 1.52 % silica, 0.02 % potassium oxide and 0.23 % sodium oxide. Flotation experiments in laboratory conditions have confirmed the validity of the proposed methodological approach to the predictive assessment of mineral enrichment. Magnetite concentrates (chamber products of reverse flotation with amines) were obtained, containing silica (1.3–1.5 %) and total iron (70.3–70.5 %) with the extraction of total iron 53-60 %. Conclusion. The results of the conducted research are recommended for practical implementation in the development of the technology of additional enrichment of ordinary magnetite concentrate at the Mikhailovsky GOK named after A.V. Varichev. The results of the conducted research are recommended for practical implementation in the development of the technology of additional enrichment of ordinary magnetite concentrate at the Mikhailovsky GOK named after A.V. Varichev.