Four new types of coal are increased through developing independently and introducing the new types of coal in Shanxi and Inner Mongolia as well as utilizing the SXLLSJM、SXJM and HDSJM, part of which is instead of such types of coal with tension supply as ZYDM and LLGHM. As a result, the scope of coal used for rammed-coal coking is expanded, tension trend of using coal is relieved, the existing coal blending structure of rammed-coal coking is optimized and coke quality is improved. The ash content of coke is reduced and the hot strength of coke is increased, which provide the strong fuel support for the stable and trouble-free operation of blast furnaces of Baotou Steel.

The process of blowing out by lowering the charge level is smooth. Moreover, the whole process without detonation, rapid blowing out with safety and environmental protection are realized through activating the furnace hearth, calculating and analyzing loading of light load materials, adopting high blowing rate in early stage to make coke burnt as quickly as possible, improving atomization device to reduce the amount of water injected into furnace top, refining tapping in stokehole, reasonably controlling the relationship between air pressure and blowing rate, shortening the time of gas release, efficiently organizing, safely placing residual iron and coordinating various systems.

In this paper, the sintering productions with such SiO₂ contents in sinter as 4.75%, 4.85%, 4.95%, 5.15% and 5.30% are carried out based on the effects of different SiO₂ contents on sinter with 500 m² sintering machine. The results showed that the drum strength of sinter was increased with gradual increase of SiO₂ content in sinter when SiO₂ content in sinter was less than 5.15%; the drum strength of sinter was optimum when SiO₂ content in sinter was about 5.15%, which was increased by 3% compared with that of 4.75% and average particle size was increased by 1.77 mm; the drum strength changed slightly with continuous increase of SiO₂ content when SiO₂ content in sinter was increased from 5.15% to above 5.30%. The analysis on the microstructure of sinter with different SiO₂ contents showed that the prismatic tabular calcium ferrite was increased with the increase of SiO₂ content and the dicalcium silicate of partial region was with large area enrichment. With the high proportion of self-produced concentrate of Baotou Steel, the SiO₂ content is controlled at about 5.15%, drum strength of sinter can reach above 79.5% and average particle size can be improved above 19 mm.

In the paper, the restraining factors affecting recycling fly ash of sintering machine head and blast furnace bag are discussed as well as the key technologies of extracting such valuable elements as Zn, K and Na from the fly ash are studied by analyzing its characteristics and disposal status. The technical plans for comprehensive utilization of fly ash of sintering machine head with high alkali metal content as well as fly ash of blast furnace bag with high zinc and alkali metal contents are proposed combining with such cases as salt extraction technology by washing for fly ash with high alkali metal content, zinc extraction technology with pyrogenic and wet processes for fly ash with high zinc content and reduction technology of electric arc furnace for iron-bearing dust as well as evaluating their merits and demerits. After implement the plans, the disposed fly ash could be recycled for sintering as well as products of Zn, K and Na could be sold externally so that the economic benefits are considerable and the problems of land occupation and environmental pollutions could be solved.

In the paper, the recrystallization annealing process is studied by taking Fe-Mn-Al-C high manganese austenitic steel as object of study. The thermal simulation tests with series of temperatures, hardness test and metallographic analysis are carried out to the test steel. The study results showed that the recrystallization temperature was 750 ℃ when annealing holding time was 120 s and recrystallization temperature was increased to 800 ℃ when annealing holding time was shortened to 60 s. The grains remain uniform and fine as well as hardness value of test steel is with a little change when the holding time is 120 s at 750~900 ℃.

In the paper, the production technology process and process control system of wide and thick plate mill in Baotou Steel are briefly introduced. The wide and thick plate mill is the important component for production line of wide and thick plate of Baotou Steel as well as its process control system is between the production management system and basic automation system in the plant, which is mainly responsible for managing production process data. The process control system model of rolling mill is generally divided into control part and non-control part. The emphasis of this paper is to research, analyze, optimize and adjust the rolling moment model of control part. After the optimization, the setpoint accuracy of secondary system model of roughing mill is improved and capacity of roughing mill is further increased.

In this paper, the oxidation and decarbonization as well as formation rule of heterogeneous particles around cracks of web for SS400B hot rolled H beam are studied. The experiment is designed based on the actual working conditions on site as well as oxidation and decarbonization and performance distribution of heterogeneous particles with different processes are analyzed qualitatively and quantitatively with metallographic analysis and energy spectrum. The results showed that there was decarburization around cracks of SS400B hot rolled H beam in the stage of rough rolling, but no heterogeneous particles appeared. It is systematically and comprehensively explained that the oxidation and decarbonization and precipitation of silicon containing heterogeneous particles around cracks are closely related to the composition of steel, process location and thermal regulation combining with domestic study results.

The chemical composition of wire rod for 2 200 MPa ultra-high strength steel strand is designed based on the chemical composition of SWRH82B. The Φ14 mm wire rod is rolled by second heating and cogging with 280 mm×380 mm continuous casting billet. The tensile strength of hot rolled wire rod is increased from 1 150 MPa to over 1 450 MPa by optimizing the cooling rate of wire rod. The target that the strength of steel strand reaches over 2 200 MPa after drawing is realized. The results of industrial trial production showed that the time of soft blow and deep vacuum was the key to control the size of non-metallic inclusions and oxygen content in steel as well as it should be more than 15 min; under the condition of constant casting speed and the degree of superheat is below 35 ℃, the center macrosegregation index could be controlled below 1.15; the ideal microstructure of sorbite could be obtained by controlling moderate cooling rate and optimum cooling rate was 4.89~5.62 ℃/s.

In the paper, it is introduced the detection analysis on non-metallic inclusions in rail head. In order to scientifically characterize the quantity, size and distribution of inclusions, the new method for detecting inclusions is explored. A new vertical detection surface is added by taking the sample position with the K method for cleanliness of oxide in the EN 10247—2017 standard, that is, such two sampling methods as vertical plane and inclined plane are adopted separately. The quantity, size and distribution of inclusions in rail head are statistically analyzed with fully automatic optical microscope as well as the compositions of typical inclusions are analyzed with scanning electron microscope and energy disperse spectroscopy. The distribution and sources of inclusions in the rails of Baotou Steel are comprehensively analyzed, which provide technical support for further improving and controlling the cleanliness of rail steel.

The requirements for surface quality of non-oriented silicon steel are very high as well as such defects as pits and color differences are not allowed on the surface, otherwise, the normal use will be affected. The pits on surface account for a larger proportion in surface quality defects so that product delivery and economic benefits are affected. The analysis results indicated that the accretion for furnace roller was the main cause of pit defects on steel plate. The poor cleaning quality of steel plate, high oxygen content in the atmosphere of annealing furnace and wear of furnace rollers are the main causes of accretion for furnace roller. The accretion for furnace roller is significantly reduced by adopting such methods as improving the cleaning quality of incoming steel plate, optimizing atmosphere environment of annealing furnace and ensuring quality of furnace rollers so that the surface quality of steel plate and qualification rate of silicon steel products have been significantly improved.