In this paper, the present situations, existing problems for utilizing waste heat and complementary energy as well as the main factors influencing recycling waste heat and complementary energy in iron and steel enterprises are analyzed by taking an iron and steel enterprise as an example. Moreover, such measures for recycling waste heat and complementary energy as replacing heating steam by recycling low-quality waste heat, increasing power generation users to utilize surplus steam, shuting down and optimizing dispersive bathhouses as well as establishing new high-efficiency gas-steam power generation system are proposed so that the regional heating balance can be achieved, steam consumption can be reduced and utilization efficiency of waste heat can be improved after implement them.

In this paper, the problems during the long-term low-load production of 6 m large capacity coke oven of Baotou Steel are summarized. They are effectively solved by monitoring and adjusting the heating schedule and changes of coke oven so that the normal operations of coke oven and its supporting facilities are ensured.

The performance indexes of gas coal are analyzed and mastered through the experimental study on gas coal of Shaanxi and Shanxi. The coke quality is improved to a certain extent, coal blending cost is reduced, range for coking coal of Baotou Steel is expanded, tension trend of coking coal is relieved and amount of high-quality coking coal is saved by optimizing coal blending structure, reasonably using coal type and replacing part of coking coal combining with the using status for existing coal types of Baotou Steel.

In the production process of coking, blending coal as the main raw material determines not only quality of coke, but also cost and profit of coking enterprises. At present, the adjustment for proportion of single coal with experiences is mainly applied for coal blending in coking enterprises, which lacks scientific basis, so it is difficult to achieve high cost-effective coal blending scheme to optimize the coal blending structure for coking. In this paper, it is introduced the purposes of reducing cost of blending coal, improving coke quality, reducing cost of metallurgical coke and improving benefit of enterprises are achieved by using artificial neural network to predict coke quality and using simulated annealing algorithm to optimize proportion of single coal with coke quality as the constraint condition and cost price of blending coal as the optimization objective.

In this paper, it is summarized the construction for modifying the steel structure of hot blast pipe for Kalugin top combustion stove of 4 150 m³ blast furnace of Baotou Steel as well as introduced its idea and process control of construction quality so as to provide the references for overhauling pipe of hot blast stove for large blast furnace.

In this paper, the basic characteristics of low sulfur Mongolian concentrate are studied with micro sintering method and the experimental study on adding low sulfur Mongolian concentrate instead of self-produced concentrate in sintering with sinter pot is carried out. The study results showed that the low sulfur Mongolian concentrate was with such characteristics as high assimilation temperature, poor liquidity of liquid phase and high strength of bond phase; with the increase of proportion for low sulfur Mongolian concentrate replacing self-produced concentrate, the sintering yield, utilization coefficient and drum strength of sinter showed a trend of first increasing and then decreasing, solid fuel consumption showed a trend of first decreasing and then increasing as well as composite sintering indicator was optimum when the proportion was 20%.

In this paper, it is introduced the experiment of intensifying sintering by replacing part of coke powder with natural gas using sinter pot carried out in the laboratory by taking natural gas as the object of study. The study results showed that the yield of sinter, drum strength, solid fuel consumption, reducibility of sinter, low-temperature reduction degradation index and microstructure of sinter were optimum when the jet time of natural gas was 15 min and adding proportion of heat was 25%.

In the paper, the effects of such four factors as calcination temperature, calcination time, proportion of bentonite and preheating temperature on content of FeO in pellet are studied based on the actual situation of material for the production with belt type pellet firing machine of Baotou Steel. The orthogonal experiment with four factors at four levels is adopted. The experiment results showed that the factors influencing content of FeO in pellet from strong to weak were calcination time, calcination temperature, proportion of bentonite and preheating temperature. It is optimum that calcination temperature is 1 240 ℃, calcination time is 14 min, proportion of bentonite is 2.0% and preheating temperature is 600 ℃ as well as it is the worst that calcination temperature is 1 240 ℃, calcination time is 8 min, proportion of bentonite is 3.0% and preheating temperature is 900 ℃.

In this paper, the quality index of sinter is studied by adding Mongolian ore fines instead of different iron charges with sinter pot. The study results showed that there was no obvious change for quality index of sinter with 8% Mongolian ore fines instead of 8% FMG ore fines and the quality index of sinter was improved with 15% Mongolian ore fines instead of 15% WPF ore fines.

The oxygen content at end point of ultra-low carbon steel is directly related to the subsequent fabrication processing and quality of final product. The bottom blowing in the process of converter smelting and the calculating parameters of sublance model system are optimized by company so that the intensity of bottom blowing gas supply is increased, stir of bottom blowing to molten pool is strengthened and bottom blowing gas supply mode is established for ultra-low carbon steel. The results showed that the oxygen content at end point could be reduced, hit ratio of carbon content as well as temperature and oxygen content for ultra-low carbon steel at end point could be improved with the above process, which could provide better molten steel for the subsequent processes.

In the process of converter steelmaking, the carbon in hot metal and oxygen blown in form the gas mixture of CO and a small amount of CO₂ under the condition of high temperature as well as it becomes the converter flue gas. The change trend of concentration curve for CO in flue gas provides the operator with dynamic state of slag. The slag could be effectively prevented to be thick and splashed by referring to the curve of concentration of CO in flue gas at end point of converter steelmaking and concentration of CO in flue gas in the process as well as adjusting the position of oxygen lance and opportunity of adding slag charge so that the end point control is accurate and smelting is stable and trouble-free.

In this paper, it is mainly studied the comparison of feasibility, technology method and metallurgical effects for calcium treatment of high calcium line under the existing production conditions of converter steel-making with those of original iron calcium line so as to further optimize treatment process of high calcium line, improve recovery rate of calcium and fluidity of molten steel as well as reduce cost of calcium treatment per ton of steel and dust emissions.

In this paper, the comparative experiment of non-oriented silicon steel samples with weights of 1 kg (28 pieces) and 0.5 kg (16 pieces) is mainly introduced. It was found that the accuracy of the two methods was consistent, the samples with weight of 0.5 kg were more effective in quality control, time and materials consumption were saved as well as labour intensity could be reduced through comparing the data.

In this paper, it is introduced the process of technical study on manufacturing paper-thin steel strip of grain oriented silicon steel with thickness of 0.08 mm for medium frequency equipment by taking the common grain oriented silicon steel (CGO) with thickness of 0.27 mm produced by our plant as raw material as well as studied the effects of heat treatment technology with different annealing temperatures and running speeds of unit (i.e. holding time) on magnetic property of grain oriented silicon steel. 900 ℃ × 10 m/min is determined to be the optimum heat treatment technology as well as the manufacturing process of paper-thin steel strip of grain oriented silicon steel with good medium and high frequency electromagnetic property that magnetic induction intensity B₈ = 1.846 T, iron loss P_1.5/400 = 11.15 W/kg and coercive force H_c = 53.57 A/m is obtained.

The hot rolled coil plate with thickness of 3~6 mm for high strength welded pipe is successfully developed with the composition design of low carbon and microalloying of niobium and titanium as well as controlled rolling and controlled cooling process with 2 250 mm hot rolling production line of Baotou Steel. Its yield strength is greater than 670 MPa, tensile strength is greater than 750 MPa and percentage elongation after fracture is greater than 19% so that the matching of strength and toughness is good as well as it is with good cold bending and welding performances, which could satisfy the manufacture of high strength welded pipe for customers. As a result, the batch production and supply of thin gauge hot rolled coil plate product for high strength welded pipe of Baotou Steel are realized.

In order to meet the development needs of light weight, high strength, energy-saving and cost-reducing in automotive industry, the hot-dip galvanized 380 MPa grade low alloy high strength steel HC380LAD + Z for automobiles is successfully developed by Baotou Steel through the composition design of microalloying of Nb and Ti combining with reasonable hot rolling and controlled rolling as well as pickling and galvanizing technologies based on advanced equipment and technological characteristics. The production results and using effect of users showed that all its properties could meet the requirements of EN 10346-2015 standard and operating requirement of users.

In this paper, it is studied the effects of main chemical elements P and Ti in ultra-low carbon deep drawing steel as well as main production technologies (i.e. cooling mode of hot rolling, annealing temperature and annealing speed) on strength of steel strip. The yield ratio of steel strip is reduced, punch formability is improved through optimizing the performances of DC04 of Baotou Steel according to customer requirements so that they could be met.

In the paper, the effects of different hardening and tempering technologies on mechanical properties of 27SiMn seamless steel tube for hydraulic support are studied. The results showed that the yield strength and tensile strength of 27SiMn test steel were gradually decreasing as well as its impact work and elongation were on the rise with temper temperature increased within the range of 580~680 ℃; the comprehensive mechanical properties could meet the requirements of user's technology agreement, batch production was realized and performances were stable when temper temperature was 610~630 ℃.

In this paper, it is introduced the experimental study on high temperature plasticity of GCr15 steel, compared and analyzed its interior surface quality at different perforation temperatures. The experimental results showed that the plasticity of GCr15 steel was good at 850~1 200 ℃, the main reason for infolding of internal surface for steel tube was that perforation temperature of tube blank was beyond high temperature plastic range and it could be reduced if perforation temperature could be controlled within 1 200 ℃.

In the paper, the experimental study on microstructure transformation of bainite steel with different contents of Mn and Cr using full automatic transformation measuring apparatus is introduced. The effects of different contents of Mn and Cr on transformation point of undercooled austenite are compared and analyzed as well as the effects of different transformation temperatures on microstructure transformation of bainite steel are also studied. The experimental results showed that the optimum temperature of microstructure transformation for bainite steel was 330 ℃, which provides theoretical basis for developing production process of bainite steel.

In the article, it is found that the decrease of pressure of chuck can effectively improve the stability of single value for thread by checking mechanical reasons and workpiece programme starting with solving the product quality problem causing unstable main single value for thread in production. The normal pressure of main chuck is 4 MPa, it is reduced to 2 MPa by using cooperatively commands M05 and M25 of workpiece programme. Practices proved that the unstable change for stand off and taper of coupling thread could be effectively avoided and waste products with ultra-poor single value could be reduced by reducing the pressure of chuck for coupling thread to contribute to cost reduction.

The ball mill is very important equipment in the process of grinding and classification in Baoshan Mining Co. as well as its energy consumption is the most in the whole plant. Its energy consumption generally accounts for 50%~70% of that of the whole plant. It is of great significance for saving energy consumption to use rolling bearing instead of sliding bearing on ball mill. At present, the five series of secondary mills are transformed and installed with two sets of rolling bearings as well as the operation effect is better so far. The comprehensive energy consumption saving is over 10%, annual electricity fee is saved by about RMB 0.44 million Yuan through comparing the electric current before and after transformation. Moreover, the roughness could be avoided and a lot of lubricating oil could be saved.

The traditional business model of mutual feeding in Baotou Steel is with such disadvantages as manual input, data verification is difficult and influencing financial cost accounting. In the paper, it is introduced that the management system for mutual feeding is designed aiming at the low efficiency of mutual feeding business combining with the traditional mutual feeding mode, which includes project context, process flow, system and key point design. The online verification of data as well as real-time refreshing, inquiry and statistics of statement are completed by automatically collecting business data so that the synergy of business flow and data flow is realized.

In the paper, the method for analyzing titanium, arsenic and tin in cast iron with X-ray fluorescence spectrometer is discussed. With such condition experiments as sample preparation, selection of abrasive grain and drawing of working curve, the detection method determined is with simple operation and the results are reliable, which could meet the requirements for on-site rapid analysis of titanium, arsenic and tin in cast iron as well as provide technical guarantee for providing high-quality molten iron for manufacturing test steel.

In this experiment, the mercuric thiocyanate ethanol solution is as color-substrate solution and the chlorine ion content in organic amine is determined with spectrophotometry at the wave length of 460 nm. Such conditions as the amount of chromogenic agent, chromogenic time and amount of acid added are optimized by the experiment as well as the elimination test of interfering ion is carried out. The detection limit of this method is 0.034 2 μg/mL, adding standard recovery is 93.10%~104.60% and RSD≤1.75%. The method is fast, accurate as well as with high sensitivity and precision, which is suitable for determining the chloride ion content in organic amine.

In the process of magnetic separation of steel slag, the particle size and water content all change. The water content of steel slag is low, so it is easy to raise dust. In this paper, the economical and environment-friendly as well as practical and effective measures for dust suppression are formulated by analyzing the problem, reason of raising dust for magnetic separation processing line and on-site materials combining with on-site environmental monitoring data. The overall dust suppression efficiency could reach over 92% when water content of steel slag is increased to about 20% by reasonably setting fog-spray nozzle. The systemic application of wet process operation method could effectively solve the problem of raising dust in the process of magnetic separation of steel slag.