Forecasting of industrial coke quality at JSC EVRAZ NTMK based on data of passive industrial experiment. Report 1. Forecasting of CSR and CRI of industrial coke

A forecast of coke quality takes a special place in the coke production, since it enables to increase efficiency of management of batching process of various by composition and properties coals and production of coke of stably high and required quality with minimal costs. Description of a methodological approach to processing of passive industrial experiment data of blends coking at Coke production department of JSC EVRAZ NTMK presented by application selective (general) matrix. The matrix accounts various multilevel values of influence factor CSR and CRI of coke - a complex index of coking ability of blends K.п.к.Vo. It was shown that the proposed approach provides wide variations of response function (CSR/CRI) at symmetrical enough matrix, excluding predominance of any particular area of values of indices K.п.к.Vo and CSR/CRI. By applying the passive industrial experiment, based on processing of actual report data of industrial blends coking at the coke batteries No. 5-6 (wet quenching) and No. 9-10 (dry quenching) by selective matrix, mathematical models of forecast of quality of industrial coke by wet and dry quenching (CSR/CRI) were elaborated depending on coal charges properties (K.п.к.Vo) at the existing modes of their preparation and coking at the coke batteries No. 5-6 and 9-10. Verification of accuracy of the mathematical models of coke quality forecast at wet and dry quenching (CSR/CRI) processing a large actual material of industrial coking (62 coking operations in the coke batteries No. 5-6 and 58 coking operations in the coke batteries No. 9-10 showed accuracy good enough for practical application of forecasting indices CSR and CRI of industrial coke of wet and dry quenching.

Cone Clogging of Submerged Entry Nozzle in Rare Earth Treated Ultra-Low Carbon Al-Killed Steel and Its Effect on the Flow Field and Vortex in the Mold

Two submerged entry nozzles (SENs) used for casting 1300 tons and 260 tons of Al-killed steel were dissected. Several parameters including block rate, nozzle clog angle, port width, and port height of the clogged nozzle were introduced to describe the geometry of clogs in the SENs based on the dissection; furthermore, a geometry model was established to describe the characteristics of the nozzle clogging of the SENs. A large-eddy simulation (LES) coupled with the volume of fraction (VOF) method was adopted to simulate the steel–slag interface’s interaction behavior. The vortex visualization and rotation magnitude were characterized by the Liutex method. Quantitatively, the influence of nozzle clogging resulted in block rates of 0% to 45.9% on the flow and vortex distribution in the mold, and the characteristics of the steel–slag interface fluctuation were well verified in the industrial experiment.

Industrial Experiment of Goaf Filling Using the Filling Materials Based on Hemihydrate Phosphogypsum

The surface stockpiling of phosphogypsum not only occupies a large amount of land, but also seriously harms the surrounding ecological environment. The preparation of phosphogypsum into filling materials for mine filling can not only maintain the stability of surrounding rock, reduce surface subsidence, enhance the recovery of resources, but it can also completely solve the problem of phosphogypsum stockpiling. Under certain activation conditions, hemihydrate phosphogypsum has a strong cementing property. It is an important way to reduce the filling cost by using hemihydrate phosphogypsum instead of cement as a cementing material. Through laboratory experiments, the filling materials based on hemihydrate phosphogypsum were developed. In order to further verify its feasibility in practical filling engineering, the industrial experiment of goaf filling was carried out in a phosphorus mine. The results show that the filling system was simple, reliable, and easy to operate and manage. The strength of the filling body basically reached the expected strength target of 2.5 MPa in 3 days. The consolidation speed of the filling materials was faster, which is beneficial to the safe underground construction of the mine. The results of the industrial experiment of goaf filling indicate that the filling materials based on hemihydrate phosphogypsum are suitable for mine filling engineering practice, the work amount is small, and the filling cost is low.

Assessment and control of geodynamical risks under the conditions of a rock-bump hazardous complex deposit

Research has been carried out to study the peculiarities of rockbump hazards and induced seismic manifestations at the Nikolaevskoe deposit, and their close correlation with the tectonic structure of the rock massif has been established. In order to strengthen control over the rock-bump hazard in the TN-3 high-angle fault, in 2019 the observation network was expanded and continuous seismoacoustic monitoring of the rock mass at the deep levels of Nikolaevskoe deposit was organized. Monitoring data is verified by local geoacoustic method using the portable device “Prognoz L”. The results of the monitoring revealed major acoustically active zone with the main amount of seismic and acoustic events recorded during the last 5 years and occurring dynamic rock pressure manifestations. Nikolaevskoe deposit was the site of execution of the industrial experiment on regional discharge of a potentially rock-bump hazardous section of a shock blasting massif.

Phosphorus Removal Options at Induction Melting of Steel

The main aspects of effective dephosphorization of steel under conditions of induction melting are presented. Regularities of scale growth on the surface of iron, as well as the conditions of its catastrophic oxidation, are considered. An industrial experiment was conducted to remove phosphorus from steel intended for brake discs.

APPLICATION OF PROPOLIS TINCTURE TO PREVENT INFECTIONS OF BROILERS

Scientific and industrial experiment was carried out at the poultry farming on Ross308 broilers. The authors explored various schemes of application of propolis tincture for pre venting respiratory infection of poultry of bacterial etiology. The researchers arranged a control group and two experimental groups according to the principle of analogues. The groups were placed in separate isolated poultry houses. Chickens of the control group were fed with antibiotic Tilmipool (0.3 ml/l of water) aged 1-3; 14-16; 25-27 days; their poultry house was sprayed with Ecocide C (0.5%, 1 l/100 m3, exposure 60 min) on 1, 7, 14, 21-22, 28-29, 35-36 days of their life. In the 1st group the antibiotic was applied as it was in the control group; aerosol treatment was conducted with propolis tincture (dilution 1:20, 0.5 l/100 m3, exposure 60 min) during the same age periods. In the 2nd group, propolis tincture (1 ml/l of water) was applied for broilers aged 1-5; 14-18; 25-30 days combined with aerosol treatment of propolis tincture air (dilution 1:20, 0.5 l/ 100 m3, exposure 60 min) for 1, 7, 14, 21-22, 28-29, 35-36 days of their life. The most effective way to prevent respiratory diseases of poultry is seen in application of propolis tincture according to the scheme used in the experiment with the 2nd group. The scheme reduces the number of pathogenic, relatively pathogenic microorganisms in the scrapes from the laryngeal mucous membrane and in the air of the poultry house, activates the immune system and metabolism of poultry, increases livability on 3.0% and live weight on 342.7 g, which eliminates application of antibiotics for preventive measures, providing environmentally safe products of poultry farming.

Increasing Labor Efficiency Repairing Metal Structures of Heavy-Duty Quarry Machinery

Supporting metal structures of large dump trucks at open cast coal mines function under exposure to alternating cyclic load. Fatigue cracks that appear there require timely maintenance welding. Organization of repair processes is multivariant; it can be performed either by the enterprise (open cast coal mine) efforts or by special repair units. An industrial experiment carried out at Permyakovskiy and Prokopyevskiy open cast coal mines in Kuzbass has shown that type of large dump trucks’ repair works organization influences significantly process efficiency. Repair welding by enterprise efforts is the most non-productive compared to other types of repair process organization. Its specific rate is 37 per cent lower than in comparison with unstructured welding and 2.2 times lower in comparison with structured metal sheet replacement and structured welding. Structuring repair processes allows to increase their efficiency by 30...40 per cent on average. Structured replacement of the spring plate is the most productive type of metal structure repair process organization. Comparison of maintenance measurement results in accordance with Unified Norms and Prices collected book with the results obtained from the industrial experiment showed that calculation methods give underestimated values of repair processes’ specific rate.

Industrial experiment study on inclusion evolution in 95CrMo Steel

In order to clarify the evolution mechanism of inclusions in 95CrMo, the industrial experiments were conducted. The composition, morphology and size of inclusions during refining and solidifying processes were analyzed by SEM-EDS detection and thermodynamic calculations. The inclusion evolution during refining process in molten 95CrMo steel can be concluded as: Al2O3 → Al2O3-MgO-CaO/CaS → Al2O3-MgO-SiO2-CaO-CaS, which is affected by slag-metal reaction and corrosion of refractory. The change of inclusion size during refining was analyzed based on their collision and floatation behavior. The composition of inclusions in billets indicate that there were mainly five types of inclusions, including spinel with sharp angle, spherical oxide inclusion composed of Al2O3, MgO, SiO2 and CaO, oxide-sulfide inclusion with single phase, inclusion with duplex phase, and MnS inclusion. The type of inclusions affects their size. The thermodynamic results indicate that most complex oxides formed in molten steel and no spinel generated during cooling process. CaS formed in the molten steel after tundish metallurgy and there were still some CaS precipitated in solid steel. MnS precipitated after steel solidification. The calculated results based on FACTSAGE 7.1 are in agreement with experimental results on the whole.