The effects of the scratch defect at rail bottom on fatigue life of rail are studied by MTS100T fatigue testing machine. The results showed that the ability of bearing load for rail was declined and its fatigue life was shortened with the transverse scratch defect at rail bottom. The depth of scratch defect at rail bottom obviously influences the fatigue life of rail. With the scratch defect at rail bottom of 75 mm long, if its depth is 0.3 mm, the fatigue life decreases by 27.2% on average, while if its depth is 0.5 mm, the fatigue life decreases by 31.4% on average.

The distribution law of apatite mineral in a tailing of Inner Mongolia is 9.25% and content of P₂O₅ is only 3.73% so that it is low-grade phosphorus mineral. Based on the condition experiment, the open circuit test of primary rougher flotation and secondary concentration is carried out with sodium carbonate as the pH adjusting agent, water glass and HSL as the depressor as well as modified fatty acid TQHY as the collecting agent aiming at the difficult problems of low grade of apatite, many types of gangue mineral containing calcium and similar floatability. Finally, the phosphate concentrate with the grade of P₂O₅ of 33.02% and recovery rate of 78.67% is obtained as well as good separating indexes are obtained.

With the growth in the people’s living standard, the demand of resources is more and more, which leads to continuous exploitation of a large number of mineral resources in our country so that there are many ecological problems. In this paper, the ecological impacts of strip mining in desert steppe are analyzed from such aspects as plant and animal resources, land resources as well as landscape through field investigation in project area by taking the strip mining project in Dongkekeyiligeng mining area of Darhan Muminggan Liahheqi in Inner Mongolia as an example. Moreover, the suggestions on ecological conservation measures of strip mining are put forward based on the theory of restoration ecology.

In this paper, the production practices on reducing unit process energy consumption of 4 150 m³ blast furnace of Baotou Steel are analyzed and summarized. The unit process energy consumption of molten iron in 2021 reduced by 9.26 kgce/t compared with that in 2020 through strengthening the quality management of furnace burden, recovery of waste heat and power, technology-improving of energy saving and energy-saving management as well as reducing power consumption and making full use of secondary energy sources so that better economic benefits are achieved.