The process of beneficiation of fine chrome sludges on concentration tables

Processing industrial products and technogenic waste is an urgent task in mining and metallurgical industry. In Kazakhstan, processing of chrome ores of the Kempirsay group of deposits creates more than 15 million tons of sludge tailings with a chromium oxide content of up to 30 wt. %. The best results of processing fine chrome raw materials are demonstrated by Turkish enterprises that use sludge separation by size classes and enrichment on concentration tables. The authors performed a research on Dubersay tailing dump chromium sludge enrichment (Kazakhstan) using similar technological approaches, which allowed to obtain concentrates containing 51 wt.% Chromium oxide and increase the yield of rich fine chromium concentrates by 14 % compared to the existing enrichment scheme

Chemical sulfatization of chrome-containing sludges from DUBERSAY tailing dump

Waste chromium production sludge from the Dubersay tailings dump is present in huge quantities with a magnesium oxide content of up to 40 %. The chrome-containing waste was sintered at 1 100 °C, the resulting sinter was mixed with sulphuric acid when heated to 300 °C. The resulting mixture after heating was leached with water at 90 °C, the solid precipitate was washed and dried to yield a chrome concentrate containing 55,4 % Cr2O3, 8,2 % SiO2. Evaporation of the purified solution produces magnesium sulphate which is a magnesium fertilizer

Beneficiation of chrome slurry tailings at Donskoy mining and beneficiation plant (DMBP) JSC to produce hard pellets

The article is about the problem of beneficiation of finely dispersed chromium slurry tailings of “Donskoy Mining and Beneficiation Plant” JSC by chemical and gravitation methods. Chemical destruction of chromium spinelids by sulphation with a mixture of ammonium sulphate and sulphuric acid enables to transfer a part of magnesium oxide to a water-soluble state and further gravitation beneficiation on concentration tables to obtain a fine-grained rich chromium concentrate. Silica, calcium, and iron oxide additives are used to produce pellets from the fine chrome concentrate, serving as binding agents and enabling the production of hard chrome pellets during roasting. In the future, roasted pellets will be used in the smelting of high-carbon ferrochrome in electric furnaces

Obtaining of strong chromium pellets with the use of a ferrosilicon-calcium binder

The article presents the results of research on the synthesis of strong chrome pellets based on concentrates obtained by enrichment of chrome sludge. To obtain strong fired pellets from the concentrates, it is proposed to use a ferrosilico- calcium reagent as a binder, which makes it possible to increase the strength of the pellets by 2-3 times in comparison with the technology operating at “Donskoy Ore Mining and Processing Plant”. This excludes the supply of fluxing reagents during electric arc smelting of raw materials to high-carbon ferrochrome. Pellets from concentrates obtained during the processing of tailings from the Dubersay sludge storage have increased strength up to 5 330 N/pellet at a roasting temperature of 1 200 °C

Thermodynamic-diagram analysis of Fe-Ni-C-O system

The paper presents the results of calculation of thermodynamic parameters of compounds formed between the system components. Complete thermodynamic-diagram analysis of the Fe-Ni-C-O system has been carried out taking into consideration the congruent compounds. The diagram of the four-component system Fe-Ni-C-O and mathematical model of its phase structure were constructed on the basis of full thermodynamic-diagram analysis and reference thermodynamic data

Obtaining of strong chromium pellets with the use of a ferrosilicon-calcium binder

The article presents the results of research on the synthesis of strong chrome pellets based on concentrates obtained by enrichment of chrome sludge. To obtain strong fired pellets from the concentrates, it is proposed to use a ferrosilico- calcium reagent as a binder, which makes it possible to increase the strength of the pellets by 2-3 times in comparison with the technology operating at “Donskoy Ore Mining and Processing Plant”. This excludes the supply of fluxing reagents during electric arc smelting of raw materials to high-carbon ferrochrome. Pellets from concentrates obtained during the processing of tailings from the Dubersay sludge storage have increased strength up to 5 330 N/pellet at a roasting temperature of 1 200 °C

Beneficiation of chrome slurry tailings at Donskoy mining and beneficiation plant (DMBP) JSC to produce hard pellets

The article is about the problem of beneficiation of finely dispersed chromium slurry tailings of “Donskoy Mining and Beneficiation Plant” JSC by chemical and gravitation methods. Chemical destruction of chromium spinelids by sulphation with a mixture of ammonium sulphate and sulphuric acid enables to transfer a part of magnesium oxide to a water-soluble state and further gravitation beneficiation on concentration tables to obtain a fine-grained rich chromium concentrate. Silica, calcium, and iron oxide additives are used to produce pellets from the fine chrome concentrate, serving as binding agents and enabling the production of hard chrome pellets during roasting. In the future, roasted pellets will be used in the smelting of high-carbon ferrochrome in electric furnaces

A study on the beneficiation ability of manganese-containing technogenic raw materials

The work presents the results of studies on obtaining ferromanganese concentrate from technogenic manganesecontaining raw materials with grain size less than 10 mm. It is found that the main valuable minerals of the feedstock are psilomelane, pyrolusite, bementite; among the rock-forming minerals, quartz and kaolinite, often saturated with finely dispersed iron compounds, prevail. Sieving and concentration of raw materials of - 10 + 5 mm and - 2 + 0,2 mm in two-chamber jigging machine with separation of two concentrates and tailingпs allowed to obtain a joint manganese concentrate with 35,1 % manganese content, 11,5 % iron content with 78,23 % manganese recovery. The obtained manganese concentrate is suitable for further metallurgical processing

Technology of production process and encapsulation fruit and berry concentrates

The article presents 2 methods for making concentrates from fruits and berries, which were later used as a filler for alginate capsules. The results of the physicochemical parameters of the obtained concentrates are presented. Of the 15 options for the formulations of fruit and berry concentrates - capsule fillers, 11 formulations were selected, which were divided into categories "up to 7 years" and "7 +" depending on their composition. Under laboratory conditions, the technological regime for the manufacture of alginate capsules by the drop method was worked out. As a result of the single-factor experiment, it was revealed that from the moment a drop of about 6 mm in size is immersed to the formation of a capsule wall with a thickness of about 2.3 mm, 2 minutes are needed in the given experiment parameters: the concentration of alginate in the filler solution is 1 %, the Ph of the filler is 4.2, the concentration of calcium salt, where the drops are immersed to form a sphere - 1 %, the size of the drop is 6 mm, the thickness of the capsules is not less than 2 mm and not more than 2.5 mm. To prevent the process of gelation, it is necessary to heat the spheres in a bath of water at 85 °C for 10 minutes. With such a manipulation, the gelification process stops, and the center of the sphere remains liquid. Prototypes have been developed that are stable if, during storage, they are immersed in a neutral medium of the filler. Based on the results of a sensory assessment of the quality and texture of yogurt from sheep and goat milk mixed with capsules according to M. Bourne, it can be concluded that mixing the homogeneous structure of yogurt with capsules has a positive effect on the taste range, the product acquires a new look and taste, while not losing its quality