The treatment of high-salt wastewater has always been a problem for production enterprises since its salt content is high as well as it is difficult to be treated and cannot be directly discharged into the environment. The harmless treatment of high-salt wastewater is achieved by combining such technologies as membrane treatment, ozonation and evaporation crystallization as well as the salt in water is concentrated into such crystalline salts as sodium chloride and sodium sulfate. As a result, the treated water is for recycling circuit.

In order to remove the calcium and magnesium ions in ammonium sulfate wastewater, ensure subsequent trouble-free operations of water treatment process, improve quality of ammonium sulfate solid and recover magnesium resource, the calcium and magnesium ions in ammonium sulfate wastewater are removed with solvent extraction method in experiment. The P₂₀₄ and kerosene are used as extractant as well as pH value of ammonium sulfate wastewater and saponification degree of P₂₀₄ are adjusted so that the step-by-step removal of calcium and magnesium ions in ammonium sulfate wastewater is realized. The data support for industrial applications of this method is provided by such experimental conditions as determining pH values of the solution and comparing.

With the rapid development of society, the requirements of market for quality and performance of steel products are constantly increasing. The competition in the steel industry is increasingly fierce. The stable product quality is an effective way to improve market competitiveness on the basis of ensuring supply on time. In the paper, it is introduced such problems as unstable product quality and high costs are solved as well as the reform and exploration of quality management on new models of professional user-centered quality management and contract-centered steel rolling management are carried out for Baotou Steel Union Co., Ltd. in order to improve the market competitiveness of products. As a result, the stability of product quality and production efficiency are increased so that good economic benefits are created.

In the traditional quality optimization process of stamping parts, the optimization is mainly through mold adjustment so that the time and quality costs are both higher. With the early vendor involvement (EVI) of professional quality management, the computer aided engineering (CAE) analysis technology is gradually applied in the simulation of stamping automobile parts. In the paper, it is introduced the self-owned material card of Baotou Steel is successfully developed by correctly selecting such characteristic parameters as typical representative performances and yield criterion through taking the DX53D+Z product as an example as well as the research on reliability of material card is completed by the analysis on forming property of products in the Autoform software. It is verified that the self-owned material card of Baotou Steel is with higher reliability and the database of simulation material could provide data support for EVI service.

In this paper, the causes of defect of longitudinal crack on surface of Q420NQR1 continuous casting billet and rolled products with hypo-peritectic steel are analyzed as well as the control measures are put forward. The results indicated that the defect of longitudinal cracks for rolled products originated from longitudinal cracks on surface of casting blank, most of which were on the web of beam blank away from submerged entry nozzle. The inner flow field of crystallizer is studied by physical simulation. It is found that there is single circulation flow on the web of crystallizer, which directly causes the melt cinder layer of casting powder away from submerged entry nozzle to be thinner so that effective heat control is difficult to be realized at this position. The flow velocity of surface layer of liquid steel could be reduced and even distribution of melt cinder could be promoted through appropriately increasing the insertion depth of submerged entry nozzle; the quality of casting blank and rolled products could be improved combining with the uneven burden distribution mode of casting powder so that the longitudinal crack rates of casting blank and rolled products are reduced by 30% and 34% respectively.

The longitudinal crack is the main defect of Q235B steel belt manufactured by CSP production line of CSP Plant. Such measures as restore the accuracy of associated equipment, reasonably use casting powder as well as improve temperature difference of water inlet and outlet for crystallizer are summarized through the correlation analysis of process control points causing longitudinal crack by analyzing the causes of longitudinal crack for hot rolled steel belt combining with the actual situation of CSP production line. As a result, the longitudinal crack defect rate of Q235B steel belt is effectively reduced and qualified rate of hot rolled steel belt is improved.

The optimum pickling process parameters are studied through analyzing the effects of pickling process before phosphating on the quality of phosphating film and phosphating time on the premise of without changing process route aiming at the problems of discontinuous phosphating film and poor adhesive force on the surface of 25CrMo44 alloy steel. The optimum pickling process parameters are that the concentration of pickling solution is 90~110 points, pickling temperature is 40~60 ℃ and pickling time is 10~16 min., the phosphating film generated under this condition is compact, uniform and continuous as well as the adhesive force is qualified.

In order to solve the difficult problem for long distance transmission of large scale hydrogen energy with low costs, the X52M hot rolled steel strip for pipeline added with hydrogen is designed, researched and developed as well as its engineering applications are realized. It is with the design of low C and Mn, Nb and Ti alloying, extreme low contents control of P and S as well as smelting with high cleanliness and reasonable controlled rolling and cooling process. It is with excellent comprehensive performances, good low temperature toughness and resistance to hydrogen brittleness. Its dimensional precision is high and surface quality is good so that the properties of pipe body and weld seam could meet the requirements and satisfy the operating requirements of steel pipe. It is applied in the Baotou-Linhe gas pipeline for western natural gas so that the first pipeline engineering application of spiral submerged arc welded pipe added with hydrogen is realized.

In the paper, the composition design and industrial trial production process of BNS, X60QS and X65QS grade acid corrosion-resistant line pipe are introduced, the effects of normalizing, quenching and tempering processes on metallographic structure and mechanical properties of the hot rolled steel pipe are studied as well as acid corrosion resistance of the product is analyzed. The trial production results showed that the mechanical properties and acid corrosion resistance of BNS grade line pipe produced with normalizing process as well as X60QS grade and X65QS grade line pipes produced with quenching and tempering process could fully satisfy the API Spec 5L standard requirements.

The thermos mechanical control process (TMCP) has been difficult to apply in the field of seamless steel pipe. The control cooling equipment after rolling is developed combining with process flow of seamless steel pipe, the X52N seamless pipeline steel pipe is produced with on-line accelerated cooling after rolling through industrial practices as well as its physical and chemical properties and microstructure are studied. The practices showed that the costly alloy elements did not need to be added into the production with C-Mn steel, microstructure of material was regulated and controlled by on-line accelerated cooling after rolling so as to ensure mechanical properties of material to meet the standard requirements as well as follow-up offline heat treatment was not needed. As a result, the requirements of physical and chemical properties for long distance pipeline steel pipe X52N could be met so that low cost, short process and economic production are realized.