In this paper, the operation mode of power supply, protective relaying setting and ability of anti-interference electricity for medium and low voltage power network are discussed, the causes for tripping of electric equipment caused by voltage dip are analyzed as well as the corresponding control measures are proposed to reduce the economic losses caused by accidents by taking an accident of voltage dip caused by the fault of short circuit of power network as an example.

In this paper, the main causes for influencing the accuracy of coal blending in large capacity silos are obtained by analyzing its factors. The corresponding solutions are proposed based on the process flow and characteristics of equipment for large capacity silos so that the accuracy of coal blending is effectively improved.

Since the 7^# blast furnace of Baotou Steel was blown on, its operations have been stable based on strengthening the quality management of crude fuel. The furnace condition is gradually stable and trouble-free as well as various technical indicators are greatly improved through actively adjusting various systems as well as quantifying, standardizing and optimizing operations.

Due to the overall downward trend of quality of crude fuel and the material leakage of central throat pipe, the air flow of blast furnace was disordered and the furnace condition was seriously abnormal. The trend for deterioration of furnace condition is significantly remitted and the blast furnace conditions gradually tend to be stable by such means as shrinking material batch, reducing coke load, increasing furnace temperature, decreasing alkalinity, strengthening the management of tapping, replacing central throat pipe and distributing chute, adjusting the distributing system, shrinking the area of intake air from tuyere, increasing the amount of water inflow of cooling wall and decreasing the temperature of water inflow.

The whole campaign life for 4^# blast furnace of Baotou Steel is up to 18 years, which is at the advanced level in the technical practices of long campaign technology for large and medium-sized blast furnaces in China. It was found that the elephant foot shaped erosion was at the junction of hearth and furnace floor by investigation and sampling analysis for the state of erosion for hearth and furnace floor of 4^# blast furnace of Baotou Steel. Moreover, its reasons are analyzed emphatically.

In the paper, it is introduced such difficulties as the poor thermal property of coke, high content of the harmful element in the furnace, poor air permeability of stock column and difficult adjustment of initial air flow distribution are overcome by such measures as adjusting the blowing-in system and charging system under the condition of the two 4 150 m³ blast furnaces of Baotou Steel with economic furnace burden so that the problems of bending and damage of tuyere are solved as well as the period of trouble-free operation for blast furnace is prolonged.

In the pellet production, the amount of bentonite is an important factor affecting the grade of pellet ore, utilization coefficient of blast furnace and coke ratio. Its affecting factors are discussed and the solutions are put forward combining with the production reality that the amount of bentonite leaps in Rare Earth Steel Iron-making Plant, which play an important role in effectively reducing the amount of bentonite in pelletizing, improving the grade and metallurgical properties of pellet ore.

The flame cutting of continuous casting billet is the key link of continuous casting as well as the flame cutting with high efficiency and low energy consumption is the development direction for the flame cutting of continuous casting. The two dual-flow slab continuous casting machines in Rare Earth Steel Plate Plant of Baotou Steel adopt new oxyhydrogen cutting technology, which is with such advantages as neat cutting section, small kerf, few burr and low energy consumption.

In this paper, the life cycle assessment (LCA) results for U76CrRE rail produced by Baotou Steel were calculated and obtained by carrying out its LCA study. The distribution of its environmental influencing factors at each stage was analyzed as well as the energy consumption of each production process and the composition for carbon emission of outsourced products are further analyzed. The study results provide the scientific data support for the ecological design and green manufacturing of U76CrRE rail.

There are adverse effects of residual Ti on the final magnetic property of silicon steel, so the Ti content should be strictly controlled to be as low as possible when smelting silicon steel. In the paper, the sources and increment for the content of harmful element Ti are analyzed based on the data of Ti content after adding the ferrosilicon and ferro-aluminium into 60 heats of silicon steel with different thicknesses of slag layer. With the increase of silicon steel grade, the Si contentin in siliconstal is increased and the quantity of the ferrosilicon added is also increased so that the Ti content rises correspondingly; it is crucial for controlling the end-point Ti content of molten steel to reduce the thickness of slag layer simultaneously.

The fracture, inclusions and morphology of cracked BT510L were analyzed with the scanning electron microscope and metalloscope aiming at the cracking in cold bending of BT510L steel for a car factory supplied by Rare Earth Steel Plate Plant. Meanwhile, the influences of impurities such as P and S in the batch of steel were invesgated. The results showed that the inclusion of manganese sulfide at the fracture of crack was the main cause. The content of sulfur in molten steel is reduced and such defects are avoided by optimizing the control technology in refining process.

The 590 MPa grade cold rolled dual-phase steel was developed in the laboratory, its chemical composition, rolling and continuous annealing processes were studied, the mechanical properties were measured and the microstructure was analyzed as well as the effects of levelling elongation on the mechanical properties of steel belt were analyzed combining with the experimental results. The results indicated that the cold rolled dual-phase steel was with good mechanical properties by heat preservation at 820 ℃, slow cooling to 680 ℃, then rapid cooling with the rate of over 30 ℃/s to 270 ℃ to be overaging with the levelling elongation of 0.8%. Its yield strength was 376 MPa, tensile strength was 652 MPa and elongation reached 21%.

The causes for such rolling instabilities of medium and high grade non-oriented silicon steel in the hot continuous rolling process as poor strip shape, drift and scrap steel are analyzed. Starting from the influence mechanisms of stable rolling, the quick open control strategy of reheating furnace is developed by analyzing such five influencing factors as the rolling phase change zone, temperature difference of the same plate by slab reheating, strip shape of rough rolling, deformation resistance and finishing rolling speed models; the rolling phase change point is calculated and the pass distribution of rough rolling is optimized; the stability of medium and high grade non-oriented silicon steel in rolling process is improved by considering the influences of all elements on deformation resistance model of finish rolling and changing the control mode of finish rolling speed.

In the welding process for X65Q steel grade line pipe, there were such defects as microcrack and contraction cavities in the weld joint, so the chemical composition and microstructure of tube body were tested as well as the solidification process of weld joint was analyzed. The results indicated that the higher energy intensity of weld line and the lower cooling intensity after welding were the main causes for the above welding defects. Based on this, the corresponding improvement measures are proposed.

The hardenability of Y37MnCrBS steel is improved through a series of measures such as micro-alloying, formulating rigorous and reasonable manufacturing technique as well as controlling narrow component of molten steel to make all the properties of steel could meet the requirements of technical condition and all the performance indexes of Y37MnCrBS free-cutting steel produced by Baotou Steel could reach the level of the same industry.

In this paper, the main causes for leakage of cooling jacket are found out through analyzing the inner structural style of cooling jacket, quality of circulating water, production process and operation aiming at the problem that the cooling jacket of first dust remover for 200 t/h large coke dry quenching device often leaks in production run. Moreover, the optimization and improvement measures are proposed to extend its service cycle.

In this paper, the technical scheme for replacing middle section of furnace shell and cooling wall by suspending upper furnace shell in the medium repair of blast furnace is introduced, the finite element strength check for suspending tie rod and support beam was carried out with the SolidWorks Simulation software as well as it is compared and analyzed with the monitoring data for sinking of furnace shell in engineering practices.

In this paper, it is mainly elaborated the current situation and existing problems of electric blower with high electricity consumption of per ton of iron as well as analyzed its causes according to the actual situations. Moreover, the optimization aiming at the existing problems in production run ensures the safe and stable trouble-free operations and productions of blower and blast furnace, which can be generalized and for reference.

In the paper, the operable technical scheme is analyzed, summarized and concluded through field practices based on some accident cases of hot rolling strapping machine so that the maintenance personnel in the same industry can use for reference as well as quickly and accurately determine the causes of failures and take effective measures.

In this paper, it is introduced the current situation of the weighing equipment and printing system of scutcheon in the three work zones of Long Product Plant as well as the effective design scheme is put forward based on it. The system development is completed as well as the tripartite communication among the ERP system, weighing system and printing system of scutcheon is realized through software programming technology so that the desired effects of the software are achieved.

The experimental reform of replacing desulfurizer of limestone with steel slag is carried out for the gas desulfurization system of 3^# sintering machine of No.1 Sintering Workshop of Iron-making Plant of Baotou Steel to examine its desulfurization performance and stability in the ore sintering flue gas desulfurization system; the optimal relations between the desulphurization efficiency and such related parameters as the density of slurrying tank and recirculating tank, pH value and density of discharging slurry in operating regulation process are found through the experimental reform.

The limestone-gypsum wet desulphurization process was originally adopted in a desulfurization system for sintering flue gas of Iron-making Plant of Baotou Steel and the raw material of desulfurizer was the finely ground limestone powder. In this industrial experiment, the desulfurizer of calcium hydroxide was as the research object and the experimental study on part or all of limestone was replaced by calcium hydroxide was carried out. The experimental results showed that the sulfur dioxide at outlet is discharged with standard level and the consumption of desulfurizer is reduced, but the pH value of seriflux in absorption tower fluctuates greatly with the desulfurizer of calcium hydroxide in the desulphurization system for flue gas of sintering machine, which has greater influences on its long-term stable operations.

In the paper, it is elaborated the gas seepage model of goaf was established with the technical conditions for actual mining of fully mechanized top-coal caving face of a mine as well as the widths of oxidized zone of goaf with different horizontal distances and vertical distances of high drainage tunnel were analyzed with the Fluent numerical simulation software combining with the actual layout requirements of high drainage tunnel aiming at the autoignition of goaf caused by gas extraction in high drainage tunnel. The results showed that when the vertical distance of high drainage tunnel was 35 m and its horizontal distance was 25 m, the width of the oxidized zone of goaf was the smallest. The determination for reasonable position of high drainage tunnel is with the practical guiding significances in improving the gas extraction efficiency, reducing danger of autoignition of coal and ensuring green, safe and efficient fully mechanized top-coal caving face.

In this paper, the main revision content and explanations are elaborated in detail by the research work practice of revising the basic and programmatic technical standard for detection of coking products-General Rules for Detection Methods of Coking Products. Moreover, the current situation and future trend change for development of coking are discussed and analyzed to make the whole industry understand the revised standard correctly and use it normatively to boost the healthy and stable development of coking industry.

In the paper, the optimum test conditions are obtained through studying the determination for content of carbon and sulfur in all kinds of ferroalloy with high-frequency induction combustion-infrared method as well as emphatically discussing the effects of selecting such parameters as the compensation and comparison level, the shortest parsing time, amount of fluxing agent and weighing sample on the determination results. The results showed that the method was suitable for determining the content of carbon and sulfur in ferroalloy, the detection limits for carbon and sulfur were 0. 000 3% and 0. 000 2% respectively as well as their relative standard deviations were both less than 3% through determining the samples of ferromanganese and ferromolybdenum 11 times. The estimated values for all kinds of ferroalloy standard samples determined with this method were the same as their certified values.

In this paper, it is introduced the three common methods for quality detection of concrete: the resiliometer method, drilling method and ultrasonic method as well as their advantages and limitations respectively. The insufficient detection results of concrete and the low detection level can be solved by reducing structural load, structural strengthening and cast-in-place as well as strengthening the quality management, personnel training and on-site force of supervision.