Coal–oil granules derived from fine-grain coal sludge may be used to produce water–coal fuel suspension and coal–oil briquets. The fuel briquets obtained are characterized by adequate mechanical strength for subsequent transportation and fuel use. Note that briquetting decreases the moisture content of the oil granules by a factor of 2–3. That eliminates the need for additional briquet drying. The content of solid phase in the water–coal fuel obtained from coal–oil granules is no more than 50

The unique combination of physical and chemical properties of molybdenum, required by modern material science, predetermines the variety of applications of molybdenum-containing alloys and molybdenumcontaining metal products: metallurgy, various-profile mechanical engineering, electro-thermal equipment, as well as the need to systematize and update the scientific and technological information accumulated in molybdenum metallurgy. The purpose of the present work was to evaluate the current state of molybdenum production and application, including such issues as production of molybdenum trioxide, molybdenum and its alloys, industrial range of molybdenum and its alloys products, molybdenum consumption structure, identification of dominant trends and their forecasting in the medium term.Technical and economical information on production and consumption of molybdenum trioxide, molybdenum and its alloys was evaluated and systematized. The existing range of products from molybdenum and its alloys, the structure of world molybdenum consumption were evaluated, dominant trends and forecasts for the nearest period were determined. It was stated, that the main technology of molybdenum production is hydrogen reduction from high purity trioxide (up to 99.9%) in the form of powder followed by its compaction. The main producers of molybdenum are the United States, Chile, China, Peru, Canada and Mexico, which account for more than 90% of world production. In 2018, global consumption of molybdenum was about 262,000 tons, about 20% less than in 2011–2012. Ferromolybdenum is produced in Russia and abroad of various brands with molybdenum content of 50– 70%. Currently, the producers of ferromolybdenum in Russia are Sorsky, Zhireken ferromolybdenum and Nizhnevolzhsky ferroalloy plants. The total production capacity of Russian enterprises is estimated at 8.5 thousand tons of ferromolybdenum per year. Metallurgical enterprises of Russia declare production of 33 different types of intermediate products and final products from molybdenum and its alloys.

Molybdenum has a complex of practically significant properties and is widely used for alloying steels and cast irons, in the composition of alloys of various purposes, as well as a structural material in pure form. Molybdenum belongs to the group of rare metals, which causes the relevance of analytical research of the modern state of the mineral- raw material base of molybdenum, extraction and processing of molybdenum-containing ores. The results of analysis of the mineral-raw material base of molybdenum of foreign countries and Russia, assessment of prospects of its expansion are presented. The confirmed world molybdenum resources amount to 12 million tons, including domestic – 2 million tons. 75% of molybdenum reserves are concentrated in the USA, China, Chile, Peru and Canada. Description of the types of deposits of molybdenum, copper-molybdenum and molybdenum-tungsten ores, the main types of molybdenum minerals has been quoted. Methods of ore concentration of various composition for production of molybdenum concentrates, additional enrichment of molybdenum concentrate and industrial practice of molybdenum concentrate processing are considered. In terms of ore quality domestic and foreign raw material base of molybdenum are comparable. 63% of domestic production of molybdenum-containing ores is provided by OJSC “Sorsky GOK”, 33% – OJSC “Zhirekenskiy GOK”. These enterprises produce molybdenum concentrates of grades КМФ-5, КМФ-6, КМФ-7. Their production capacity is about 12 thousand tons of concentrate per year. Molybdenum concentrates are processed by pyro- and hydrometallurgical methods and are an industrial product for production of ferromolybdenum and its chemical compounds. The total capacity of molybdenum concentrate processing plants is 300 thousand tons per year.

A study of the physicochemical characteristics of mill scale and dehydrated sludge from gas purification of oxygen-converter production was made. Their chemical, phase, particle size distribution and density are determined. It was established that the total iron content in the scale is 73.3%, in the sludge – 41.2%. The technological expediency of their use in metallization processes is determined. In this case, preliminary briquetting in a mixture with a carbon reducing agent is necessary.

During the research, rolled scale and gas cleaning slimes from oxygen-converter workshop No. 1 of JSC “EVRAZ ZSMK” were used as iron-oxide-containing materials. Semi-coke from brown coals of the Berezovskoye deposit of the Kansko-Achinsk basin (temperature of semi-coking is 750 °C), coke fines of PJSC “Coke” and dust from coke dry-quenching plant of JSC “EVRAZ ZSMK” were used as carbon reducing agents. Total iron, FeO and Fe2 O 3 oxides amount to 73.3, 75.5 and 20.9 % in scale, 41.2, 4.7 and 53.7 % in sludge, respectively. Sludge also contains 4.3 % of total carbon and 20.6 % of CaO. Brown-coal semi-coke, coke fines and coke dust contains carbon and volatiles 94.05 and 9.5 %, 97.50 and 2.1 %, 97.47 and 1.6 % on dry ashless weight, respectively. For metallization of furnace charges with composition: scale, slime–semi-coke, coke fines, dust with addition of 10 % water-soluble binding–molasses, strong unroasted briquettes were pressed. Metallization modes of analyzed charge compositions were thermodynamically predicted and technologically determined. Metallization degree and metal iron content at usage of brown-coal semi-coke were found to be 97.5 and 90.2 % for scale, 97.5 and 71.3 % for sludge; of coke fines: 70.7 and 61.9 % for scale, 68.9 and 48.4 % for sludge; of coke dust: 72.1 and 62.6 % for scale, 69.2 and 48.2 % for sludge. The possibility of achievement the metallization degree of 97.0 – 98.0 % was established for briquetted charge from scale – brown-coal semi-coke with 92.0 – 93.0 % of total iron, 89.8 – 90.6 % of metallic iron, 2.8 – 3.2 % of FeO, 0.06 – 0.08 % of S, 0.016 – 0.018 % of P, 1.7 – 1.9 % of C, 1.0 – 1.2 % of CaO and 0.25 – 0.35 % of MgO at 1173 K and duration of 40 min.

During the research, rolled scale and gas cleaning slimes from oxygen-converter workshop No. 1 of JSC “EVRAZ ZSMK” were used as iron-oxide-containing materials. Semi-coke from brown coals of the Berezovskoye deposit of the Kansko-Achinsk basin (temperature of semi-coking is 750 °C), coke fines of PJSC “Coke” and dust from coke dry-quenching plant of JSC “EVRAZ ZSMK” were used as carbon reducing agents. Total iron, FeO and Fe2 O 3 oxides amount to 73.3, 75.5 and 20.9 % in scale, 41.2, 4.7 and 53.7 % in sludge, respectively. Sludge also contains 4.3 % of total carbon and 20.6 % of CaO. Brown-coal semi-coke, coke fines and coke dust contains carbon and volatiles 94.05 and 9.5 %, 97.50 and 2.1 %, 97.47 and 1.6 % on dry ashless weight, respectively. For metallization of furnace charges with composition: scale, slime–semi-coke, coke fines, dust with addition of 10 % water-soluble binding–molasses, strong unroasted briquettes were pressed. Metallization modes of analyzed charge compositions were thermodynamically predicted and technologically determined. Metallization degree and metal iron content at usage of brown-coal semi-coke were found to be 97.5 and 90.2 % for scale, 97.5 and 71.3 % for sludge; of coke fines: 70.7 and 61.9 % for scale, 68.9 and 48.4 % for sludge; of coke dust: 72.1 and 62.6 % for scale, 69.2 and 48.2 % for sludge. The possibility of achievement the metallization degree of 97.0 – 98.0 % was established for briquetted charge from scale – brown-coal semi-coke with 92.0 – 93.0 % of total iron, 89.8 – 90.6 % of metallic iron, 2.8 – 3.2 % of FeO, 0.06 – 0.08 % of S, 0.016 – 0.018 % of P, 1.7 – 1.9 % of C, 1.0 – 1.2 % of CaO and 0.25 – 0.35 % of MgO at 1173 K and duration of 40 min.

Results of studies of physical and chemical properties of rolling scale and dewatered sludge from gas-cleaning system of BOF plant quoted, carried out for estimation of technological advisability of application them in metallization processes. The studies carried out by application of standard methodics of determination of chemical, phase, grain-sized contents and density of fine and powder materials. It was determined, that content of total iron, FeO and Fe2O3oxides, Sulphur and Phosphor in the scale makes figures 73.3, 75.5, 20.9, 0.036 and 0.019 % correspondently, in the sludge – 41.2, 4.7, 53.7, 0.21 and 0.15 % correspondently. The sludge contains also up to 20.9% of CAO and 4.3% of total carbon. Grain-size contents of the scale and the sludge are considerably different: content of size grade +1.0 mm and –0.016 mm is in the scale 63.3% and 0%, in the sludge – 14.8 and 44.5 % correspondently. Real density of the scale is 4.6–4.9 g/sm3. The results obtained confirm a technological advisability of application of fine-grained scale and powdered sludge in metallization processes, including their preliminary briquetting comprising carbonic reduction agent.

Thermodynamics is investigated and optimal temperature-time regimes of carbidization of briquetted charge “microsilica – brown coal semi-coke” are determined. In Si-O-C and Si-O-C-H systems the carbide formation process is dominant: with the stoichiometric composition of the charge, the maximum content of silicon carbide reduction products is achieved at 1700 K. The complete carbidization of the charge in the conditions of heat treatment is achieved at a temperature of 1923 - 1973 K with a duration of 20 - 15 minutes. The technological expediency, conditions and chemical enrichment indices of carbidization products are established. The phase, chemical, granulometric compositions and morphology of silicon carbide particles are studied. It was found that carbidization forms a carbide of the cubic structure (β-SiC). The content of carbide after enrichment is more than 90%. Silicon carbide is obtained in the form of a micropowder with a specific surface area of 8000 - 9000 m2/kg from irregularly shaped particles with a size range of 0.2-1.0 μm.

Silicon carbide may be produced from fine-grain batch consisting of two main components: microsilica waste; and semicoke obtained from Berezovsk lignite (Kansko-Achinsk Basin). The physicochemical properties of the silicon carbide are certified in the present work. Two forms of microsilica are considered: (1) microsilica formed in the production of silicon (containing 93.41–95.33% SiO 2 ; 1.96–3.28% C free ; 0.30–0.34% Si free ; and 1.25–1.45% CaO + Fe 2 O 3 + MnO); (2) microsilica formed in the production of high-silica ferrosilicon: (containing 91.72–93.63% SiO 2 ; 0.56–1.18% C free ; 0.18–0.20% Si free ; and 1.38–2.32% CaO + Fe 2 O 3 + MnO). Its specific surface is 21000–24000 m 2 /kg. The microsilica is inclined to form spherical aggregates measuring 200–800 nm. The aggregates consist of spherical particles ranging in size from 30 to 100 nm. The lignite semicoke contains 94.05% carbon, 9.2% ash, 0.2% sulfur, and 0.007% phosphorus; its specific surface is 264000 m 2 /kg. The composition of the silicon carbide is investigated, along with its specific surface; the size and shape of the carbide particles are determined. In both cases, the predominant phase is cubic silicon carbide (β-SiC), with an accompanying glassy phase consisting of silicates of calcium, magnesium, and iron. When the batch containing microsilica from ferrosilicon production, the silicon carbide is accompanied by α iron. In synthesis at 1923 and 1973 K for 50 and 90 min, respectively, polymorphic conversion of β-SiC to α-SiC p is observed. The content of silicon carbide in the products is 82.52–84.90%. Chemical enrichment of silicon carbide proves expedient. The optimal enrichment conditions are as follows: the action of hydrochloric acid (concentration no less than 35%) at 353 K for 3 h, with a 1:2 solid/liquid ratio. The enrichment characteristics are as follows: the content of silicon carbide in the products is 90.42–91.10%; and 87–95% of the impurities (metal oxides and iron) are removed. The silicon carbide is obtained as micropowder consisting of irregular particles (size 0.2–1.0 μm) with specific surface 8000–9000 m 2 /kg.

The paper describes the conducted physical-chemical certification of silicone carbide, obtained from fine-grained charge of two kinds, which contains microsilica formed at the production of silicon and high-silicon ferrosilicium, as well as semicoke from brown coal of Beresovskii deposit of Kansk-Achinsk basin. Microsilca of both kinds contains 93.41 – 95.33 % and 91.72 – 93.00 %, 63 % of SiO 2 ; 1.96 – 3.28 % and 0.56 – 1.18 % of С своб . ; 0.30 – 0.34 % and 0.18 – 0.20 % of Si своб . ; 1.25 – 1.45 % and 1.38 – 2.32 % of (CaO + Fe 2 O3 + MnO). Microsilica has a specific surface of 21 000 – 24 000 m 2 /kg and is inclined to aggregation with the formation of spherical units with the size of 200 – 800 nm. The units consist of spherical particles with a dimensional diapason from 30 to 100 nm. Brown-coal semicoke contains 94.05 % of carbon; 9.2 % of ash; 0.2 % of sulfur; 0.007 % of phosphorus and has a specific surface of 264 000 kg/m 2 . Phase and chemical compositions of silicone carbide, its specific surface, the size and the form of carbide particles have been studied. It has been established that in both cases predominate phase is silicon carbide of a cubical structure (β-SiC), but an accompanied one is a glassy phase, formed with lime silicate, magnesium and iron. At carburizing of charge, containing microsilca of the production of ferrosilicium, α-iron accompanies to silicon carbide. At the synthesis temperature of 1923 and 1973 K and the duration of 50 and 90 minutes polymorthic transformation of β-SiC into α-SiC II occurs. The content of silicon carbide in the products of carbonization is 82,52 – 84,90 %. The authors of the work have established the viability and optimal conditions of chemical enrichment of silicon carbide: influence of hydrochloric acid with the concentration of not less than 35 % at the temperature of 353 K, ratio of Т:Ж = 1:2, durability of 3 hours. The indexes of chemical enrichment have been defined: the content of silicon carbide in the products of enrichment is 90.42 – 91.10 %, removal of impurities of metal and iron oxides of 87 – 95 %. Silicon carbide appears as micropowder with the particles of wrong form with the dimensional range of 0.2 – 1.0 um with the specific surface of 8000 – 9000 m 2 /kg.

Проанализированы состояния производства, свойства и области применения полукоксов из отечественных малометаморфизованных углей различных месторождений.Сопоставлены свойства (зольность, содержание фиксированного углерода, выход летучих на сухую беззольную массу, реакционная способность, удельное электросопротивление, химический состав золы и др.) буроугольных полукоксов из углей Березовского месторождения Канско-Ачинского бассейна, Таловского месторождения Томской области, пламенного угля Кузбасса марки Г, угля марки ДГ Черемховского месторождения Иркутского бассейна.Установлено, что наиболее перспективно производство и потребление буроугольного полукокса Березовского месторождения КАБ ввиду его более высоких свойств по сравнению с полукоксами из малометаморфизованных углей других месторождений, технологической возможности его крупнотоннажного производства, относительно низкой стоимости, а также значительной потребности в нем

The paper presents the researches at the temperatures of 1873, 1923, 1973 К and duration of 5 – 30 min of carbidization of briquetted monocharges, consisting of microsilica, formed at the production of silicon and its alloys and diff erent carbon deoxidizers: brown coal and coal-mine semi-cokes, coke fi nes and coke dust. It has been established that the highest indicators are reached at carbidization with the use of brown coal semi-coke of Berezovskii deposits of Kansk-Achinsk basin: the yield of silicon carbide is 97.00 – 97.62 % at its content in the products of carbidization of 82.52 – 84.90 %. The optimum temperature-time conditions and the indicators of carbidization have been defi ned, namely: the temperature of 1923 – 1973 К at the duration of 20 – 15 min. The dominant phase in the products of carbidization is silicon carbide of a cubic structure (β-SiC). As a result of chemical enrichment, the content of SiC in carbide is 90 – 91 %, i.e. it is higher than in abrasive micropowders with the granularity of 1 – 2 μm. The enrichment effi ciency from the impurity of oxides and iron is high and makes 87 – 95 %. For silicon carbide a high content of silica is typical – more than 7 %; that allows considering it as a perspective material for the production of carbide-silicic refractory materials on a silica band. Silicon carbide has been received in the form of micropowder with the particles of irregular form with a size diapason of 0.2 – 1.0 μm.

The paper describes thermodynamic experiments to determine the optimal temperature and time modes for the carbide production process from the briquette charge comprising silica fume and brown coal semi-coke, conditions for chemical enriching of silicon carbide, its phase, chemical and granulometric compositions and particle morphology.

The research of the metallization process of the roll scale and sludge after gas treatment in the BOF production with the use of brown coal semicoke mined in Berezovsky field of the Kansk-Achinsk Basin was carried out. A flow diagram of “cold” briquetting using a water-soluble binder was offered. The reduction of iron from its oxide Fe2O3 with brown coal semicoke in the laboratory electric-tube furnace in the argon atmosphere was studied. The mathematical models of dependence of the metallization degree on variable factors were developed. The optimal values of technological factors and essential characteristics of the obtained metallized products were revealed.

The formation of silicon carbide from briquetted batch consisting of microsilica waste from silicon and silicon-alloy production is investigated. The batch is treated at 1873, 1923, and 1973 K, for 5–30 min, with various reducing agents: lignite semicoke, coal semicoke, coke breeze, and coke dust. The best results are obtained when using lignite semicoke from the Berezovsk deposit in Kansko-Achinsk Basin: the yield of silicon carbide is 97.00–97.62%; it constitutes 82.52–84.90% of the products obtained. The optimal treatment temperature and time are determined: 1923–1973 K for 15–20 min. The products consist predominantly of cubic silicon carbide (β SiC). Chemical enrichment increases the SiC content in the products to 90–91%; this is higher than in abrasive micropowder of grain size 1–2 μm. The effectiveness of enrichment in terms of oxide and iron impurities is high: 87–95%. The silicon carbide is characterized by a high silica content: more than 7%. Accordingly, it may be regarded as a promising material for the production of siliconcarbide refractories used in silica binder. Silicon carbide is obtained as micropowder with irregular particles in the size range 0.2–1.0 μm.

Thermodynamics is investigated, and the optimum temperature and time modes of carbonization of a briquetted silica fume batch-brown coal semi coke are defined. The complete carbonization of the batch in the conditions of heat treatment is achieved at a temperature of 1923 - 1973 K within 15 - 20 minutes. The conditions and indicators of the chemical enrichment of carbonization products are established. After enrichment, the carbide content is more than 90%. Silicon carbide micro-powder is obtained with a specific surface area 8000 - 9000 m(2)/kg.

The possibility of using iron-ore concentrates from the Bachkar field and lignite semicoke from the Talovskoye field (Tomsk region) to obtain highly reduced pellets is considered. The high tar yield in the heat treatment of lignite hinders its use as a reducing agent in industrial processes and necessitates its conversion to semicoke. Analysis of the properties of carbon-based reducing agents indicates that lignite semicoke is more reactive than metallurgical coke and has a more developed porous structure. Semicoking of the lignite is optimal at ∼600°C, with roasting for about 40 min. The tar is completely removed, and the residual quantity of volatiles is sufficient for reduction by carbon in a hydrogen-bearing atmosphere. The production of iron-ore pellets from lignite semicoke is studied; the conditions of reductive roasting and the characteristics of the process are determined. At 950°C, 90–92% reduction is achieved after around 1 h. A production system for reduced pellets based on iron-ore concentrates and lignite semicoke in shaft furnaces is developed. The gases formed in the reduction of oxides (CO + H2 + H2O) provide the heat required for the process.

Global production and consumption of silicon carbide have been appraised. The expediency of using of technogenetics microsilica for production of silicon carbide by the methods of furnace synthesis and plasmametallurgical technology has been showed. Balance scheme for the formation of silicon monoxide based on a study of physical and chemical interactions in the ore-smelting furnaces for smelting silicon and ferroalloys has been suggested, as well as the processes analysis responsible for the formation of silica fume has been carried out. Schemes of mechanisms of carbonthermal synthesis and plasmametallurgical synthesis of silicon carbide have been offered.

Исследована термодинамика и определены оптимальные температурно-временные режимы карбидизации брикетированной шихты «микрокремнезем -буроугольный полукокс».В системах Si-O-C и Si-O-C-H процесс карбидообразования является доминирующим : при стехиометрическом составе шихты максимальное содержание в продуктах восстановления карбида кремния достигается при