Improvement of a Preparation Process of Chromite Raw Material Used for Ferroalloys and Pigments Manufacture

Abstract

<p>The given article contains the research results of carbon-containing chromite pellets’ production from off-grade raw material with application of internal coal-mining overburden rocks as flux. Besides, for the purpose of improvement of ecological situation in industrial regions and expansion of a raw-material base for ferrochrome and pigments manufacture we suppose to use in a charge composition the dust of aspiration units and electrostatic precipitators, which is formed at the preparation of raw materials and production of chromite pellets. The production technology of chromite pellets with use of a slime formed at the concentration of chrome ores as a binding substance was developed. Testing the suggested technology has been carried out in laboratory and trial conditions. The data of a chemical composition of initial components of a charge and calcined carbon-containing chromite pellets have shown economic and ecological efficiency of the developed technological process. Research results lead to the conclusion that the proposed granulation feedstock mixture pellets with a moisture content of 11–12% are obtained crude granules have a compressive strength of 2.3–3.2 kg/splashed. Increasing the content of Cr<sub>2</sub>O<sub>3</sub> in the pellets to 7.6% occurs due to the increase in the extraction of chromium oxide and due to the charge of chromium oxides contained in the sludge, as well as removal of the batch formulation was heat treated carbonates, and volatile organic substances. It was established that during this mode, the temperature in the lower layers is about 1200 °C, and a reduction in natural gas consumption achieves 50% and the residual carbon content in the pellets is about 1.5%, which leads to improvement of technical and economic indices of production chromite pellets and ferrochrome.</p>

Research on the Production of Pigments Based on Composite Pellets in the Recycling of Industrial Waste

“…Preliminary drying of the composite pellets was carried out at a temperature of 573-673 K for 15 min; then, the temperature in the pellet layer rose to 1427 K, and the pellets were kept at temperatures of 1227-1427 K for 20-25 min. Upon reaching a temperature of 1427 K in a layer between 100 and 200 mm, a decrease in the flow of natural gas to the gas-burner device was carried out with an excess of oxygen necessary for the combustion of carbon in the composite pellets containing internal overburden rocks [42][43][44].…”

“…Currently, in the world practice for the production of pigments for the textile industry, there are many ways to obtain them based on chromium compounds, but the use of composite industrial waste in the form of internal overburden of coal mining, substandard chromite ores, and dust from aspiration systems has not been sufficiently studied. A systematic approach to chromite waste has not been developed as a raw material for the production of composite pigments containing surface-active modifiers and used for printing on cotton and mixed fabrics [5,6].…”

“…Chromite ores are from light gray to gray with various inclusions, and internal overburden rocks are from light brown to dark brown, depending on the content of iron-manganese and chromium impurities in them [22][23][24].…”

THE RESPONSE OF in vitro CULTURED CELLS OF Linum grandiflorum Desf. ON THE ACTION OF POLLUTANT AND HERBICIDE

“…Most likely, L. grandiflorum cells are resistant to the studied metal concentration. This may be due to the fact that flax belongs to the group of accumulator plants, in which the toxic effect of the metal is expressed at higher concentrations of pollutant compared to other cultures, which are mainly exclusives that accumulate heavy metals in Glyphosate serves as an inhibitor of one of the enzymes of phenolic metabolism responsible for the initial stages of the biosynthesis of these secondary metabolites [10]. When it entered the plants, in some cases a decrease in their accumulation was noted [31].…”

“…In modern agroecological conditions, there is a problem of weed grass infestation of field and decorative crops, for which herbicides that can suppress plant growth are widely used [9]. These include glyphosate N-(phosphonomethyl) glycine, a post-emergent non-selective herbicide of systemic action, which ranks first in the world in production among preparations of similar action [10]. Glyphosate is a unique inhibitor of the shikimate biosynthetic pathway key enzyme for aromatic compounds 5-enolpyruvilshikimate-3-phosphate synthase, as a result of which the synthesis of proteins and secondary metabolites of a phenolic nature is suppressed in plants and deregulation of energy metabolism is also observed [11].…”