The pertinence of refining slag and inclusions is investigated as well as the influences of chemical composition, basicity and oxidizability of refining slag on size, morphology and category of inclusions in steel are analyzed based on the production process of rail steel. The results showed that the proportion of single particle inclusions with the size bigger than 50 μm decreased when the basicity of refining slag R was controlled at 2.0~2.5 and oxidizability of refining slag was controlled at about 0.6%.

Woerte Mining Co., Ltd. processes various ores. The content of rare earth in the tailings after beneficiating iron is higher, the rare earth in tailings of Woerte is effectively recycled with the flotation method and thought of individual processing aiming at the problems of complex ore properties and many influencing factors for mixed ore. The results showed that under the better experimental conditions, the rare earth ore concentrate with concentrate grade of 52.00% and recovery rate of 56.05% was finally obtained so that more significant economic benefits were obtained.

The optimization for mixing system of ore pulp is studied aiming at such problems as the mixing blade drops out, gear and bearing of reducer and bearing of agitator damage, equipment failure rate is high as well as maintenance cost is much due to the system operates in the environment of high temperature, much steam and high ore pulp density for a long time. The equipment failure rate is reduced and service life of the system is improved through such measures as improving the structure of mixing impeller assembly, breather of reducer, flow condition of steam and steam heating tube so that stable operation of the system is realized.

In the paper, the effects of different chlorides and alkali metal vapor on the thermal properties of coke are studied. The study results showed that the damage of potassium chloride on the thermal properties of coke is the most serious, the effects of calcium chloride and magnesium chloride on degradation of coke take second place as well as the effects of sodium chloride on degradation of coke are the fewest. After the elemental potassium vapor adsorbs on coke, the thermal properties of coke are seriously damaged so that the CRI of coke increases to more than 60% and CSR reduces to less than 35%.

In this paper, it is analyzed such problems as frequent blockage of outlet pipe for sulfur melting device, unbalance of discharge for sulfur foam pump, agglomeration of foam tank and low desulphurization efficiency in the operation of ADA desulphurization system in old Coking Plant of Baotou Steel as well as proposed the improvement measures so that the stable operation of ADA system is implemented and the quality of gas is greatly improved.

In this paper, it is introduced in view of the low qualification rate of slag basicity for 6^# blast furnace of Baotou Steel, the qualification rate of blast furnace slag basicity in 2020 is increased by 19.42 percentage points compared with that in 2019 by such measures as improving the stability ratio for basicity of sinter, formulating reasonable slag-making system, detailing operations of section chief, overcoming various instability factors for furnace condition at later stage of campaign and strengthening management, which lay the foundation for trouble-free operation and improvement of indexes for blast furnace.

In the paper, it is introduced the experimental study on adding ore fines of Roy Hill in sintering is carried out with sinter pot as well as the quality indexes and pyrometallurgical performances of agglomerate with different proportions are systematically studied. The study results showed that the ore fines of Roy Hill could substitute the Australian ore fines to be used in sintering productions and it was recommended that the proportion should be controlled within 20% on the premise of guaranteeing the stability of quality indexes and pyrometallurgical performances of agglomerate.

In this paper, such performances of FMG mixed powder as chemical composition, granularity composition, assimilability and liquid phase fluidity are studied aiming at the problem of quality reduction after add FMG mixed powder into 500 m² large sintering machine of Baotou Steel. The results showed that the FMG mixed powder was with moderate content of SiO₂, low content of P, coarse particle size, better assimilability and liquid phase fluidity, so its performances are complementary to those of self-produced iron concentrate used for sintering of Baotou Steel. After add a large proportion of FMG mixed powder, the drum strength of sinter could remain unchanged by such measures as strengthening granulation, reasonable burden distribution and adjusting gas permeability of bed of material.

The effects of different TiO₂ contents on the basic characteristics of sintering and quality index of sinter are studied with small sintering method and sintering cup. The study results showed that the liquid phase fluidity index and generative capacity of calcium ferrite decreased, the strength of binder phase tended to decrease and strength of crystal stock tended to increase with the increases of TiO₂ content in iron charge and assimilative temperature; the yield and drum strength of sinter decreased as well as solid fuel consumption tended to increase; the magnetite content in mineral composition of sinter tended to increase, crystal obviously increased, production of calcium ferrite decreased, perovskite content tended to increase and the change of hematite was not obvious; the low-temperature reduction degradation index of sinter tended to get worse and melting range became narrower.

In this paper, it is introduced the baking-free high-performance permeable brick is prepared with the process tests of compression moulding and extrusion molding respectively by taking the tailings after beneficiating iron of an abandoned mine in China as the object of study. The blending strategies for compression moulding and extrusion molding processes are put forward. The permeable bricks prepared with the two processes are with excellent properties and could meet the requirements of building materials so that the business cycle of treatment of wastes with processes of wastes against one another is realized.

The causes for surface crack defect of 25Mn2RE seamless steel pipe are analyzed and detected with the metalloscope, scanning electron microscope and energy dispersive spectroscopy. The results showed that its defects were mainly due to the cracks on the surface of billet and a large amount of iron oxide was formed inside the crack by heat with high temperature. Moreover, the serious banded structure of matrix caused transverse crack defect on the outer wall of pipe and bumps formed due to the banded structure of the inner wall of pipe delaminated when the pipe was subject to bigger circumferential extrusion stress during the tubulation and forming process of user.

The product design, production as well as the tests of microstructure and properties for X42MS hot rolled coil for pipeline steel resistant to H₂S corrosion are carried out aiming at the technical demands of user. The design content includes chemical component, hot rolling process and production technology process. The performance tests include stretch, bending, impact, hardness, metallographic phase, nonmetallic inclusion, hydrogen induced cracking (HIC) and sulfide stress corrosion cracking (SSCC). The experimental results showed that the X42MS hot rolled coil for pipeline steel resistant to H₂S corrosion manufactured by Inner Mongolia Baotou Steel Metal Manufacturing Co., Ltd. could meet the technical requirements and its batch production was realized.

In this paper, it is introduced the development process for 340 MPa grade high strength galvanized auto steel sheet with IF steel of Baotou Steel. It is successfully developed through chemical composition design, formulating hot rolling and galvannealing processes as well as the r value for products reaches over 1.5. After the successful test mold by user, the product has been with supply mass at present.

Different types of fracture morphology of DWTT sample for X80 pipeline steel are analyzed. It is found that the causes are related to such as the microstructure, segregation and inclusions of materials by metalloscope, scanning electron microscope and energy spectrum analysis.

At the preliminary stage of production test, there were cracks on the DP590 dual phase steel of Baotou Steel in the metal spinning process of user. It is found that the main cause for cracks is the martensite banded structure in the center of steel plate by analyzing and studying the position with cracks. The measures for improving the center segregation of casting blank are proposed so that the problem is solved.

In the article, the welding preheating temperature, welding cold crack sensitivity and welding heat-input of weathering bridge steels Q370qNH and Q420qNH are studied with different welding experiment parameters. The reasonable range of welding heat-input, welding material selection and welding process parameters of Q370qNH and Q420qNH are determined by comparing the comprehensive mechanical properties and metallographic structure of welded joint so that the performances of welded joint can meet the operating requirements of product.

Under the condition of commercial production, the effects of rare earth addition in steel on low temperature impact performance of rail are studied. The results showed that the rail treated with rare earth was with good low temperature toughness and its impact value at-40 ℃ was twice as high as that of experimental steel without rare earth; the microstructure of experimental steel was pearlite and ferrite. The inclusions could be spheroidized as well as the plasticity and toughness of rail could be improved by adding the rare earth.

It is found that the main cause for surface defect of billet is low straightening temperature aiming at the problem that the surface crack rate of Q355B casting blank produced with the 280 mm × 380 mm billet and 5^# casting machine of Baotou Steel is higher through studying the correlation between straightening temperature of billet and surface cracks. The high temperature thermoplasticity of steel could be changed by adding trace Ce element so that the probability of surface cracks for billet is greatly reduced within the straightening temperature range of 850~950 ℃.

In this paper, it is analyzed the cause for frequent damage of electric butterfly valve for CSQ coke quenching car is the working condition cannot be met. The fault of water drain valve is completely solved and the moisture of coke after quenching can be ensured by taking away the electric butterfly valve, redesigning and replacing with the "cover plate valve" with pneumatic control, which could completely meet the technological requirements so that the target of transformation is achieved.

As a key spare part in the production, the working status and service life of material chute of blast furnace directly affect the stable production of blast furnace. In this paper, it is introduced the service life of material chute is improved by studying and analyzing the reasons for its shorter life as well as redesigning, remanufacturing and using new materials, which plays a positive role in the stable and trouble-free running of blast furnace.

In this paper, it is introduced the development process of video monitoring system and video protocol, analyzed the current situation and existing problems for video monitoring system as well as the purpose and significance of video monitoring system integration in Baotou Steel. The feasible integration scheme for several video monitoring systems with different private codes and transmission control protocols is proposed, which is with certain practical values.

In this paper, it is mainly introduced the principle and implementation method of double cross-limit control as well as the parallel cascade combustion control system based on double cross-limiting is designed on the basis of briefly elaborating the technological process of hot blast furnace. The practical applications show that the automatic control for combustion and blowing-in of hot blast stove can be realized as well as the combustion efficiency and control accuracy of hot blast stove are greatly improved with the system so that hot blast stove can operate safely and efficiently.

On the premise of constant production and operation of gas desulfurization system, such goals as reducing its operating load, stabilizing the operation of desulfurization facilities and reducing the emission concentration of pollutants at outlet are achieved through taking such measures as adjusting the proportioning of sintering raw material structure, controlling the temperature and flow rate of flue gas as well as improving the efficiency of main electrostatic precipitator.

In this paper, it is considered to be the main cause for decline of dissolved oxygen that the load of organic matter in aerobic tank increases rapidly by analyzing the typical example for decline of dissolved oxygen in aerobic tank of biochemical system for coking waste water. Verified by experiment, the concentration of dissolved oxygen in aerobic tank could return to normal within 1~2 days by taking such measures as increasing the aeration rate of aerobic tank, adding the water with low COD concentration into aerobic tank and strictly controlling the amount of organic matter entering aerobic tank.

It is a key link to detect the oxygen and nitrogen content in rail blanks in the production of rails. In this paper, it is mainly elaborated the method for preparing oxygen and nitrogen sample with drilling of hollow drill instead of traditional gas cutting forging. The experiment results showed that the method could meet the production requirements. Moreover, the process flow was simplified, sample preparation cycle was shortened, cost of sample preparation was reduced and timeliness of data was ensured compared with the method for preparing oxygen and nitrogen sample with gas cutting forging.

The effects of manual and automatic measurements on the measurement results are discussed through analyzing the measurement of percentage elongation after fracture of cold-rolled steel plate produced by Baotou Steel. The results showed that there were some differences between the percentage elongations after fracture with manual and automatic measurements as well as the original gauge length and fracture position were determining factors. When the measurement requirements for percentage elongation after fracture of metallic material are more accurate, manual measurement should be adopted to ensure measurement results to be closer to the mechanical characteristics of material itself.