High-temperature (over 1600 °C) combustion of chlorine-containing waste immediately destroys all organic compounds including dioxins, furans, chloro-phenols and others. However, subsequent
cooling of chlorine-containing gas to temperatures below 500 °C creates conditions for the secondary synthesis of dioxins. The study fi ndings show that the probability of dioxin formation in this case
rises with the increasing of oxygen, chlorine and fl uorine contents with the concurrent decreasing of sulfur content in the waste gas. For the effi cient suppression of secondary dioxin formation, waste
should be incinerated at a minimum residual oxygen content in the gas whilst high contents of chlorine and fl uorine should be reduced by high-temperature (at 600 – 1000 °C) gas neutralization by chemi-
cal compounds of alkaline or alkaline-earth elements (e.g. by injection of powdered sodium carbonate into the gas).

The article presents the results of the study of thermal stability of wet iron-ore pellets obtained by heat-spraying technology of wet charge on charge pelletizer skull, as well as on the clumping off-grade pellets. The experiments involve the pellets obtained by the technology of nucle-
ation by spraying and additional clumping and the technology of nucleation, pelletizing and spraying. These pellets have structural heterogeneity on the moisture content. The former has the reduced moisture content in the center of the pellet; the second one has lower moisture content
in the coat of the formed pellets. It is established that the cracking temperature and shock fracture increase signifi cantly with the decrease of moisture content in the center (nucleation by spraying and additional clumping) and in the coat (the technology of nucleation, pelletizing and spraying) of pellets as compared with the conventional technology. It was found out that in case of equality of the total moisture content of the pellets obtained by the technology of nucleation by spraying and additional clumping and the technology of nucleation, pelletizing and spraying, their fracturing temperatures differ signifi cantly. The boundaries of the moisture ratio of the surface layer and the central part of the pellet, achieved by each of the offered technologies and affect directly the heat
resistance parameters are also different from each other. In particular, the structural heterogeneity of the pellets according to the moisture content at which a minimum amount of moisture is contained in the central area of the pellet (the technology of nucleation by spraying and additional
clumping), has the largest interval of the moisture ratio. For the pellets, obtained according to the technology of nucleation by spraying and additional clumping in the interval of the moisture ratio, it is possible to raise the cracking temperature at 240 °C compared to pellets formed according to the technology of nucleation, pelletizing (560 °C). The pellets, obtained according to the technology of nucleation, pelletizing and spraying, have the boundaries of the moisture ratio in the surface and
central parts, which are signifi cantly less. Within these boundaries the change in heat resistance according to the criterion of crack formation does not exceed 40 °C.

Nitriding of the Fe – 3 % Si alloy was studied by spectral chemical analysis and scanning electron microscopy with local X-ray analysis. In-depth chemical composition was determined by glow discharge optical emission spectrometry (GD-OES). The process has been studi ed in the 500 – 1000 °C temperature range. Nitriding was performed in the proprietary system using (95 % N2 + 5 % H2 ) inert carrier gas ammoniated by passing through NH3 aqueous solution. Parameters of the nitriding were optimized. Nitriding of the Fe – 3 % Si alloy was performed after decarburization annealing. Most of nitrogen in the form of disperse Si3N4 phase is located in the near-surface region just after the inner oxide layer. Increasing the nitriding potential caused the austenite formation in the internal oxidation layer that should impair the insulating coating formation in the subsequent processing. The nitrogen content in the nitrided Fe – 3 % Si alloy decreased during the high temperature annealing; the remaining nitrogen content became equal to the aluminum content right before the beginning of abnormal grain growth.

This paper presents a method for calculating the basic parameters of the gas jet (average temperature and power) at a certain distance from the nozzle exit in the technology implementation of blowing molten slag on the refractory lining of the converter. The mathematical model has been worked out and the fl ow parameters of the supersonic noncalculated jet, considering joining in the working volume of 350-t converter not only gas but also slag particles, have been calculated. Average weight values of temperature and velocity over the length of the gas jet have been obtained. The effect of the added slag mass on the added mass of gas, the temperature of the gas jet and its rate subject to the changes in the fl ow of nitrogen through the nozzle and the relative temperature in the working space of the converter has been established. The analysis of the results of numerical calculations has showed that the slag ejection changes signifi cantly the picture of the interaction of ternary supersonic noncalculated jet with the melt, at the same time even a slight attachment of slag to the gas fl ow promotes noticeable decrease of the propagation velocity of the jet.

The model of hot drawing of steel cylindrical billets of small diameter in the combined anvil blocks for obtaining of forgings of a circular section was constructed. The authors considered the plane strain schema. The calculation of stressed state is the way to solve a problem of Michel for an elastic wedge, a problem of Flaman for a semi-infi nite plate and offered before method of an assessment of transferring in plastic condition of billet at drawing in fl at anvil blocks. The temperature stresses were not considered; the elastic modulus of the billet material depends on temperature. The fi elds of tensors of elastic stresses in the billet, three concentrated forces caused by action were defi ned; the fi eld of total stresses depending on angle of cut of the inferior anvil block was constructed. The assessment of stresses in a region of prospective plastic fl ow in the preparation section, leaning against limiting values of intensity of a tensor of the elastic stresses caused by action of three concentrated efforts was obtained. The example of drawing of the billet of steel 45 (Russian grade) was considered. Identifying limiting intensity of elastic deformations εуп with technical yield point ε0.2 = 0,002 and estimating elastic modulus Е of steel 45 100 hPa at temperature 950 °С, the authors have received values of coeffi cient of load at the moment of transferring of a part of billet material in plastic condition and distribution of component total tensor of stresses. The level of intensity of the stresses, corresponding to transferring of billet material into plastic condition, has defi ned the border of plastic layer. The conforming graphs were presented. Dependence of distribution of a component tensor of stresses from angle of cut of the inferior anvil block was received. The optimality of angles of cut of 120° of the inferior anvil block was confi rmed for drawing operations of the billet.

The effect of the severe plastic deformation modes on the ultrafi ne-grained state forming in zirconium Zr – 1Nb alloy comprising precipitations of secondary phases in the form of particles in the volume and at the grain boundaries was studied. Pressing with a gradual temperature decrease in the range of (973 – 573) K was established to dissolution of the secondary phase precipitates and forming the ultrafi ne-grained grain-subgrain structure in the alloy with an average elements size (0.25 ± 0.10) mm. In the pressing process at room temperature with an intermediate hour annealing in the temperature range of (873 – 803) K forming of ultrafi ne-grained structure with an average size of elements (0.45 ± 0.18) mm was observed. At the same time the secondary phase particles were retained in structure. The ultra fi negrained structure forming leads to the increase in the values of tensile and yield strengths of Zr – 1Nb alloy in 1.5 – 2.0 times and the simultaneous increase in the propensity to the localization of plastic deformation and decrease of the values of uniform strain and deformation to failure. Presence of secondary phase’s particles in ultrafi ne-grained structure as an increase in the size of its elements prevents the development of the plastic deformation localization and increases the effect of strain hardening.

The paper presents the results of a research of microstructure and mechanical properties of bioinert alloys based on titanium, zirconium and niobium in ultrafi ne-grained condition. Ultrafi ne-grained condition was received by a combined method of severe plastic deformation, which included high-cycle abc-pressing at a given temperature regime, a multi-pass rolling in shaped rolls at room temperature and low temperature prerecrystallization annealing. The annealing increased the plasticity of alloys in ultrafi ne-grained condition without changing the grain size. In the two-stage severe plastic deformation and annealing the ultrafi ne-grained structure was formed in the alloys. The average element size of the grain-subgrain structure was 0.16 – 0.25 μm, which provided a signifi cant improvement in mechanical properties (ultimate strength, yield strength and microhardness) of the alloys compared to their original hard-grained or fi ne-crystalline conditions. At the same time, the formation of ultrafi ne-grained conditions in alloys did not lead to any change in the elastic modulus with a signifi cant increase in their strength and plasticity.

The paper is devoted to the investigations of the structure and properties of the diffusion layer of the samples after boriding and boron-chrome plating. It has been revealed that when boriding, diffusion layers are formed with a high content of high-boride phase; it reduces the plasticity of the layer. The research on boron diffusion saturation of the working surface of the punch for cutting goals has been carried out. It has been established that during the work under dynamic loads they experience friction. The receiving of fragile boride layers does not cause the increase of operational properties of such products. It has been found out that the alloying of chromium boride layers reduces the fragility of the diffusion layers. By optimizing the process of boronchrome plating for these products the following parameters have been identifi ed: the composition of the coating, the temperature of diffusion saturation, exposure time. It has been proposed to combine chemicothermal treatment of punches in coating and heating of products for hardening. The possibility of replacing the alloyed steel by carbon steel with the investigated diffusion coating has been shown.

It has been shown by scanning electron microscopy that the formation of the deposit facing on steel surface is accompanied by the creation of a multilayer structure including a layer of welding, transition layer and layer of the heat-affected zone. Crystallization of facing is accompanied by the formation of a columnar structure, which presents alternating layers of two types of thickness 8 – 10 microns. Layers of the first type are characterized by a lamellar structure oriented perpendicular to the substrate surface, the thickness of the separating plates and intermediate layers in the layer varies in the range of 50 – 100 nm. Layers of the second type have a structure of lamellar and globular type. On a distance from the surface facing the lamellar structure of the first type layers degenerates and completely disappears on the border with the transitional layer. The globules sizes vary in the range of 1.5 – 3.0 microns, globules are fragmented. The gradient nature of the structure is identified in the transition layer and the heat-affected zone also. It was established that the boundary facing – steel is in elastically stressed state, formed as a consequence of ultra-high heating and cooling velocities; this was evidenced by the presence of micropores and microcracks, located line-by-line, as well as by extended intermediate layers of the second phase.

Estimation of the effi ciency of linear connection modeling of factorized working conditions (13 variables are represented in 4 orthogonal factors) with 4 responses on injury rate is shown using regression and canonical analysis. It is established that a multiple correlation coeffi cient R for the responses taken by itself (injury cause, site and type of accident, severity of injury) has an average value = 0.38 including statistically signifi cant factors and canonical connection of these arrays taken into account in a target experiment is characterized by the value R = 0.6156. This is comparable with a human factor infl uence on injury rate (R = 0.4639) being identifi ed in the course of parallel experiment with the array data of person injured in consequence of health and safety accidents. At that, factor arrays considered in a target experiment do not have statistically signifi cant canonical correlation R = 0.2314. Practically the same informational value of the investigated arrays F (working conditions) and T (injury rate) was revealed after the target experiment completing.

The article presents the technological features of the charge choice for fi lling the blast furnace. The developed complex of mathematical models and software was designed for charge calculation to
fi ll the blast furnace with adjustable process of slag formation and recovery. When blowing, the fi rst portions of slag-forming and iron-ore materials were located in the furnace shaft and there was no need for gradual improvement of the ore load. The basic functional capabilities of the software allowed the following: manual maintenance (the structural characteristics of blast furnaces; the parameters of the previous blowing-in, properties of slag-forming and iron ore materials, coke, and others); the calculation of the charge for fi lling and cast iron and slag properties at user-specifi ed spending of slag-forming materials and fl uxes and blast parameters; calculation of the optimal charge composition for fi lling and blowing selection subject to the restrictions in heat, slag, gas-dynamic regimes and the quality of the cast iron; diagnosis and presentation of calculation results in tabular and graphical forms, saving them in the database.

The authors developed the emergency control system for crushers. It allows using the joint estimation of parameters of mechanical and electrical parts, elimination of emergency situations from falling into the zone of destruction of uncrushed solids.

The article describes the results of the experimental researches of new type complex ferroalloy (silicomanganese with barium) produced with the use of Shubarcol non-dressed coal as a reducer. It was established that for the production of silicomangenese containing 0.9 – 1 % of barium Si/(Mn + Fe) in ferroalloy should be 0,3.