Content Of Harmful Impurities Research Articles

Marketing component of resource-saving environmental technologies of fallen leaves utilization

The article is devoted to the formation of marketing-mix elements for resource-saving ecological technologies of fallen leaves utilization that basis on technological process analysis. There is no doubt about statement that fallen leaves are beautiful. However, the romance of autumn leaves charms everyone, except those people, which forced to clean it up. In situation when people got a lot of trees and bushes on the garden, they need to clean leaves as fast as possible in order not to damage the grass cover. Every year utility workers and gardeners go to “battlefield”, several times raking tons of fallen leaves and piles of leaves that also serves as shelter for small animals and promotes for saving and reproduction of microorganisms. Meanwhile dissolution of the leaves emits methane gas, which is more than 20 times more destructive that CO2. Despite the ban and big fines, people continue to burn leaves piles, guided by habit and reluctance to spend on the payment of removal. Considered that fallen leaves should be disposed of as organic fertilizer and processed as organic fuel. A fundamental review of the existing waste disposal and recycling technologies was carried out leaves. Author offering a solution about resource-saving eco-technology of the disposal fallen leaves and gives his opinion about the prospect of further development of existing progressing technologies, exception is obtaining biogas. Also explained the tendency of consider them as interesting technical solution that has been tested, for example creating a resource-saving eco-technology for the disposal of fallen leaves. Resource-saving eco-technology and equipment that works autonomously for bio recycling and heat recycling of leaves which fallen is proposed for consideration. That helps you to avoid many problems such as design-technological and organizational-logistic. Technology doesn’t require operations of grinding, washing, re-grinding and pressing, which makes it unnecessary to involve the most difficult mechanisms and devices which isn`t cheap. That equipment has no heating system, which makes insignificant values of indicators of combustion, heat generation, content of harmful impurities; thermobriquettes are transportable which excludes the ingress of moisture and oxygen. Also, cross terrain vehicle can`t transport leaves or biomass, it doesn’t increase fuel consumption during heavy traffic.

ТЕХНОЛОГИЯ ВЫПЛАВКИ СПЛАВА 12Х18Н10Т В ИНДУКЦИОННЫХ ПЕЧАХ

A technology for making structural cryogenic steel 12Х18Н10Т from industrial waste has been developed. For it an induction plant was used which consists of two FS-series induction-arc furnaces. Problems of furnace charge preparation were considered: the fractional composition, oxidation, content of harmful impurities and a charging way. It made possible to ensure pot resistance and to decrease the melting period. Recommendations to decrease meniscus height on the melt surface are given.

Study of corrosion characteristics of motor oils used in gas-diesel engines of BelAZ mining dump trucks

Comparative studies of the corrosion characteristics of motor oils used in internal combustion engines of BelAZ 75131 mining dump trucks using liquefied natural gas - methane - as a motor fuel are presented. It is noted that an increase in the lead concentration in waste oil of internal combustion engines of mining dump trucks can be influenced by the used motor oil when it is interacting with the crank mechanism bearings liners, which have lead in their composition. The research technique is presented. The data on the pH values of the studied neat motor oils and their oil-in-water emulsions are given. It is noted that the effect of moisture and atmospheric oxygen on various types of motor oils of the same manufacturer's brand affects the formation of either water-soluble organic acids that contribute to the corrosion attack on lead or its alloys, or the formation of water-soluble alkaline organic compounds that have a neutral effect on lead and its alloys. This fact suggests that motor oils used in internal combustion engines of mining dump trucks have various corrosion characteristics that eventually affect the content of harmful impurities in waste oils.

Features of electron beam welding of molybdenum alloy ZrMo2А

ABSTRACT The paper demonstrates the positive experience of fighting hot cracks in electron beam welding of molybdenum alloy СМ2А by double passage by an electron beam, which led to a decrease in the content of harmful impurities in the seam. The structure of the compounds obtained is shown, and their hardness and the content of harmful impurities are measured.

Flotation enrichment of resistant gold ores

Ores of the Vasilkovsky deposit include arsenopyrite, pyrite, pyrrhotite, marcasite, gold, chalcopyrite, sphalerite, galena, faded ore (tennantite)S, bismuthine, native bismuth, lellingite, molybdenite, cubanite, bornite, antimonite, relict minerals, magnetite, apatite and apatite chromite, sericite, chlorite, potassium feldspar, tourmaline), quartz, carbonates (siderite, ankerite, calcite), fluorite, barite. Arsenopyrite is the main ore mineral. It contains the bulk of gold, as well as impurities - copper, cobalt, nickel, bismuth, zirconium, titanium, lead, zinc, antimony, silver, molybdenum. Bismuth and its minerals are widespread, they are constantly associated with arsenopyrite, forming intergrowths with native gold, less often with chalcopyrite and faded ore. Native gold is distributed very unevenly, forms the finest precipitates ranging in size from tenths of a micron to 0.063 mm, grows together with quartz, arsenopyrite, pyrite and bismuth minerals. Rich ores were formed by combining bismuthcontaining associations with arsenopyrite. The role of gold in arsenopyrite increases with depth. Ores are of the gold-quartz-sulfide type. Quartz in ore up to 90 %, sulfides from 3 to 5 %. The content of harmful impurities (arsenic) reaches 2 % or more. Ores are refractory, require special technology for the beneficiation and extraction of gold.

On the development trends of the machine-tractor park of the agro-industrial complex of Russia

Currently, agricultural machinery is characterized by low technical level and high wear. The tractor fleet is basically based on outdated machines that do not meet modern requirements for the consumption of operating (fuel and oil) and construction materials, reliability, environmental impact (water and air basins, soil, the content of harmful impurities in exhaust gases), working conditions and level of automation and other indicators. The wide use of combined harvesters shows significant shortcomings typical of currently produced combine harvesters. Extremely high concentration of operations in one machine, typical of modern self-propelled combines, with high productivity, severe restrictions on harvesting, loss and damage to grain, with high requirements for durability and reliability leads to an increase in machine weight. As a result, there are problems to increase its cost, soil compaction during harvesting, reducing crop yields, and highly qualified personnel for operation, maintenance and repair. The article analyzes the trends of further development of agricultural machinery, based on the solutions proposed in the Russian-Belarusian patents, aimed at solving these problems.

Associative connection of molecular genetic and biochemical markers with the character of chronic fl uoride intoxication in aluminum industry workers

Introduction.Th e aluminum industry belongs to the industry with a high status of occupational pathology. The study of metabolic bases and hygienic aspects of fl uorosis is a priority section of modern occupational health. Organ failure occurs in a separate group of workers, despite the equivalent conditions of production and may be due to biochemical polymorphism.The aimof the study was to explore the associative relationship of molecular genetic, biochemical markers with the nature of chronic fl uoride intoxication in workers of the aluminum industry.Materials and methods. Th e complex of clinical and genetic parameters of workers of Novokuznetsk aluminum plant with the determination of the content of harmful impurities in the air of the working areas was evaluated. Statistical analysis was carried out using IBM SPSS Statistics 22.Results. Over 25 years of observation, the maximum risk of intoxication was observed in the workplaces of electrolyzers, anodes against the background of metabolic disorders. Th e associative relationship of CYP, GST, SOD genes with the nature of fl uoride intoxication was determined.Conclusions.Th e development of fl uorosis is predetermined by the hereditary component. Markers associated with the dynamics of metabolic maladaptation allow to predict the course of the disease.

Technology of Melting an Invar in an Induction Furnace

A process of melting a 32NKD superinvar alloy from industrial wastes in a 1100-kg FS (core-free) induction furnace is developed. The preparation of a charge, namely, fraction composition, oxidation, the content of harmful impurities, and a method of charging, is considered in detail to ensure the maximum resistance of a crucible and to optimize melting. The methods of decreasing the height of the meniscus that forms on the melt surface because of the specific features of induction heating and the related features of slag formation are analyzed.

Monitoring Fluorine in Metallurgical Fuel

The environmental impact of metallurgical fuel, which includes various types of mineral fuel (such as coke, coal, lignite, peat, fuel shales, and their derivatives) is a continuing concern. In the combustion of metallurgical fuel, harmful materials (chlorine, fluorine, sulfur, and arsenic) are released, with consequent environmental degradation. Safety regulations regarding coal production include restrictions on the content of harmful impurities and their limiting permissible concentrations. On account of the broad distribution of fluorine in nature and industry, it is of special importance to monitor the fluorine content in metallurgical fuel. Physical methods based on the excitation of various radiation spectra permit determination of the fluorine content, without decomposition of the initial solid sample. However, such methods have problems in terms of sensitivity, precision, and the complexity of the equipment required. In the ion-chromatographic, ionometric, and other methods, the samples are broken down, and the fluorine content is determined in solution. Usually, high-temperature processes are used for decomposition of the samples: pyrohydrolysis, combustion in oxygen and in a calorimetric bomb, and alkaline fusion. In the present work, a selective method is developed for the ionometric determination of fluorine, by means of a fluorine-selective electrode. Samples of lignite, gas coal, semicoke, and coke nuts are investigated. The samples may effectively be decomposed by two-stage high-temperature melting with KNCO3. Fluorine is transferred to solution in the form of free fluoride ions by means of hydrolytic codeposition of interfering cations with chloride iron(II). The analytical procedure is described. It consists of decomposition of the sample and the ionometric determination of fluorine. The precision and truness of the proposed method is verified by variation in the sample size. In the samples considered, the fluorine content is within the limits typical of commercial coal. That indicates that the use of the samples in fuel is environmentally acceptable. The proposed method is promising for the monitoring of fluorine impurity in metallurgical fuel. It is selective and simple to use.

Research on Plasma Electric Arc Granulation Processes of the Ural Region Mineral Raw Materials to Welding Materials for Submerged Arc Welding

This article offers a qualitatively new approach for production fused welding fluxes granules, based on the use of a plasma arc and the Ural region raw materials that have a particularly low content of harmful impurities. The processes of fused welding flux granules forming from the Ural region mineral raw materials under the impact of a highly concentrated energy source have been studied. A new fused welding flux for submerged arc welding is produced by plasma electric arc granulation, and has required shape and fractional, chemical and phase composition of the particles. This research presents experimental and theoretical studies of interaction processes of fine-dispersed batch from mineral raw materials with a highly concentrated energy source, aimed at obtaining new information about the basic patterns of the formation, structure and composition of resulting granules of functional materials, such as welding fused fluxes.

The Structure and Properties of High-Carbon Ferrochromium Powder Produced from FKh800 Ferroalloy

The structure, chemical and phase compositions, and process properties of the high-carbon ferrochromium powder produced by grinding the lump pig FKh800 ferroalloy have been examined. The pycnometric and bulk densities of the powder and its compressibility at 600–800 MPa have been determined. It is shown that the content of harmful impurities, S and P, in the FKh800 powder complies with the requirements of GOST 4757–91. The resultant powder consists of complex (Cr, Fe)7C3 carbide and a solid solution of carbon in chromium ferrite.

High-energy ultrasound to improve the quality of purifying the particles of iron ore in the process of its enrichment

The iron-magnetite raw material extracted in Ukraine is characterized by a complex texture, structure, and a high content of harmful impurities such as silicon dioxide, potassium oxides, sodium, magnesium, and sulfur. At the same time, the requirements for the quality of iron ore concentrates entering the further metallurgical processing are increasing, as the high quality of magnetite concentrates can significantly reduce the cost of metallurgical production. Meanwhile, the quality of concentrates decreases mainly due to the formation of technogenic micron splices in the iron ore pulp. The main reason for the formation of gaps is the presence of ion-electric and molecular fields on the surface of the ore particles. The formation of technogenic gaps reduces the difference in the properties of the surface of the ore and nonmetallic grains; it changes their magnetic susceptibility and, consequently, the efficiency of separation methods. Analysis of the results of studying the influence of the dynamic effects of high-energy ultrasound on the ore pulp showed the promising use of this approach. To improve the efficiency of cleaning the surfaces of minerals, it is proposed to pre-treat the iron ore slurry with the help of high-energy ultrasound. The optimum values of the intensity and the duration of ultrasonic treatment in the purification of mineral particles have been determined. When cleaning mineral particles, the intensity should be 1.2 W/cm 2 , and the processing time should not exceed 60 seconds. In this case, the yield of the purified product is increased by 0.8 %, and its quality grows by 0.9 %. It has been proven that the efficiency of ultrasonic treatment is associated with the renewal of particles surfaces, which leads to an increase in the contrast of magnetic and flotation properties of minerals. The study has shown that ultrasonic treatment of the iron ore pulp in the Kremenchuk iron ore region of Ukraine allows reducing the content of harmful impurities: potassium oxide – from 0.19 to 0.035–0.04 %; sodium oxide – from 0.14 to 0.027 %.

Development of Slag Base for Welding Fluxes from Man-Made Mineral Formations of Ural Mining and Smelting Companies

Slag bases for welding materials have been developed from mineral raw materials and man–made mineral formations of the Urals. Successful comprehensive studies and tests of fused fluxes and also of weld metal and weld joints obtained by these welding materials have been carried out. It has been clearly established that the obtained weld metal has low content of harmful impurities ([S] is as low as 0.01 wt%) due to the use of the electric arc furnace method, purity of the feedstock minerals and technogenic raw materials and physicochemical reactions during the welding process.

Research on the Effects of the Refining Treatment to the Properties of Dual-Phase Wear-Resistant Steel

Using refining agent to proceed refining treatment on dual-phase wear-resistant steel, the refining agent is made up of CaO, CaF2, Al2O3, Al, Na2CO3 and BaCO3. The experimental furnace is 25kg vacuum induction furnace, stalling 10 minutes after adding the refining agent, the heating temperature is between 1550 and 1600°C. By doing this, the content of harmful impurities including O, N and S in the steel is significantly reduced and the mainly existing form of the main non-metallic inclusions is changed, it also reduces the size and number of the microstructure of the inclusions in the steel and improves the impact toughness and elongation of dual-phase wear-resistant steel significantly.

Highly efficient technologies and modern equipment for obtaining semifinished products made of heat-resistant foundry alloys for use as charge materials

An efficient technology has been developed for making and casting heat-resistant foundry superalloys in modern vacuum-induction furnaces. The technology ensures the production of high-purity alloys with a low content of harmful impurities and a stable chemical composition. The main characteristics of the equipment used to make the superalloys are presented.

Key trends in the development of a metallurgical technology to meet the growing steel quality requirements

The recent increase in the requirements for the service properties of steels of certain grades is discussed. The main trends in this field are noted, and examples are given for improving technological processes according to these requirements that ensure a stable chemical composition of steel, a decrease in the content of harmful impurities, and a decrease in the number of “dangerous” nonmetallic inclusions in steel. It is important to create and effectively use through technological schemes and models for the production of steel products that can correct the process of the next processing stage depending on the results of the previous stage.

Intensification of water purification by reagent method

On the example of real dispersal system (effluent) are tested coagulants and flocculants of different nature. A decrease in the content of harmful impurities after working up of the system by the reagents is established by the methods of physicochemical analysis.

New steels for pipelines of strength classes K54–K60 (X70): Production experience at OAO MMK

1 Current specifications on pipe for gas and oil pipelines call for high strength, low-temperature strength, and weldability of the metal. In the present work, we consider the production of high-quality sheet (thickness up to 16 mm) of strength classes K54‐K60 (X70), with improved low-temperature strength (even in drop tests) and weldability, on the 2000 mill at OAO Magnitogorskii Metallurgicheskii Kombinat (MMK). This sheet is intended for the manufacture of straight- and spiral-seam pipe without subsequent heat treatment. According to current concepts, satisfactory properties of the metal sheet and pipe are obtained as a result of the formation of fine ferrite—bainite structure [1, 2]. The required structure is ensured by a steel composition with 0.03‐0.07% C and microalloying with Nb, Ti (V), as well as elements (Mo, Cr, Ni, Cu) that increase the stability of austenite in polymorphic transformation during controlled rolling with accelerated cooling. It is necessary here to minimize the content of harmful impurities ( ≤ 0.003‐0.005% S, ≤ 0.010‐0.012% P) and nonmetallic inclusions [1‐3]. It is expedient to produce the sheet for pipe production—straight-seam pipe (diameter 530 mm), twoseam pipe (diameter 1020 mm), and spiral-seam pipe (wall thickness up to 16 mm)—on continuous broadstrip hot-rolling mills. In the manufacture of spiralseam pipe from metal subjected to controlled rolling, there is no need for subsequent heat treatment (quenching + tempering), which is widely used by foreign producers [4]. For the 2000 mill, controlled rolling with accelerated cooling is characterized by a finite number of reductions in successive roughing and finishing cells, limited thickness of the sheet for the finishing group, and small pauses between deformation stages [5]. The sheet with a thickness of 8‐16 mm is cooled more 1 Participants in this research included B. F. Zin’ko, V. V. Savenkov, S. A. Gorshkov, P. A. Stekanov, V. Yu. Salo, and E. A. Kudryakov. slowly than in thick-sheet mills. The most important stage in the operation of the broad-strip mills is winding, which largely determines the final structural type and morphology of the steel, its conditions of dispersional hardening by the deposition of Nb and V carbides, and the cementite distribution.

Improved use of powder wire in steel metallurgy

Ladle treatment of hot metal by magnesium-bearing powder wire is in increasing use at metallurgical enterprises, since it does not involve large capital and operating expenses and it ensures effective desulfurization, stability of the results, and considerably reduced toxic emissions [1]. This technology is used today at OAO Mariupol’skii Metallurgicheskii Kombinat im. Il’icha, OAO Tulachermet, OAO Lipetskii Metallurgicheskii Zavod Svobodnyi Sokol (LMZSS), and elsewhere [2, 3]. At OAO LMZSS, ladle treatment of hot metal by magnesium-bearing powder wire is included in the production cycle for commercial cast iron and cast-iron pipe. In the blast-furnace shop, a push-rod system is installed in the region of the casting machines; both commercial iron cast in pigs and hot metal sent to the pipe-casting shop for further treatment in induction furnaces and pipe casting undergo desulfurization in 100-t ladles. In the mixer department of the pipe-casting ship, where necessary, the hot metal undergoes desulfurization in 30-t ladles to ensure a sulfur content of less than 0.012%. In the modification section, the hot metal is treated in 7-t ladles for 5‐10 min after discharge from the induction furnaces. After treatment, the ladle with the hot metal is sent on a trolley directly to the section for centrifugal pipe casting [4]. The technology ensures a stable residual-magnesium content of more than 0.025% throughout the pipe-casting cycle, permits considerably more efficient use of the magnesium, and significantly reduces the costs of modification; the pipe obtained meets all the standard requirements regarding microstructure and mechanical properties. Magnesium‐staurolite wire is used for desulfurization, and ferrosilicon‐magnesium wire is used for modification. The characteristics of ladle desulfurization of hot metal by magnesium‐staurolite/ferrosilicon‐magnesium wire in 30-, 100-, and 140-t ladles are shown in the table. (The data for 140-t ladles are taken from [4].) The results indicate that desulfurization is highly effective when using magnesium-bearing powder wire. Ladle treatment of hot metal by magnesium‐silicon alloy considerably improves the efficiency of magnesium utilization. The cost of removing 0.01% S is $0.5‐ 1.0/t if the initial content is ≥ 0.03% S, and $1.2‐1.6/t if the initial content is ≤ 0.02%. The degree of magnesium assimilation for the different groups of hot metal at OAO LMZSS is 90.2‐98%; the coefficient of magnesium utilization in sulfur removal K Mg‐S is 28.8‐46.4%; the magnesium consumption is 0.3‐0.5 kg/t. In steel production, treatment of the melt with calcium-bearing reagents is very effective and, in view of non-Russian experience, essential. In the production of high-quality metal for major gas and oil pipelines, shipbuilding, and the construction industry, ladle treatment with calcium-bearing powder wire is a key part of steel production and an effective means of improving the properties of liquid and solid steel. Calcium has a significant influence of the kinetics of steel reduction, refining, modification, and microalloying [2, 5]. At metallurgical enterprises where the melt is treated with calcium, the casting of steel reduced by aluminum is not a problem. The negative influence of alumina in the melt and in the final product is eliminated; the content of harmful impurities, oxides, and sulfides is reduced; and the composition and shape of the nonmetallic inclusions are modified. This improves the steel quality. The relative elongation is increased by 10‐15%, and the impact strength of thick rolled sheet is increased (by a factor of 1.5‐1.8), with simultaneous increase in strength (by 5‐10%) and decrease in the cold-brittleness threshold (by 15‐20 ° C). The surface

The use of siderites in blast furnaces operated on unfluxed pellets

Bakal siderites represent an important source of iron ore that can be used in the production of high-quality pig iron and steel. Their value in this regard stems from the stability of their chemical composition, low content of harmful impurities (sulfur, phosphorus), good reducibility, and good strength in the roasted state. These advantages, combined with the favorable composition of the country rock-which has a basicity (based on CaO + MgO/SiO2) of up to 2.6-makes it possible to classify these siderites as iron-fluxes that can be used effectively in a blast furnace. Roasted siderite concentrate (RSC) can be used efficiently in the blast-furnace charge to make different grades of manganese-bearing foundry iron as long as unfluxed pellets are also employed. On the average, the addition of 10 kg of RSC to the charge per ton of pig iron reduces the consumption of dry skip coke by 0.6–1.5 kg/ton pig and increases furnace productivity by 0.9–2.0 tons/day by decreasing the amount of raw flux needed and increasing the iron content of the fluxed part of the charge.