The grade of fluorite ore concentrate of Bayan Obo Iron Mine is difficult to be improved under the existing reagent system since its main impurities are fine-grained disseminated iron mineral, rare earth and part of monomeric barite. The barite mineral can be restrained effectively, grade of fluorite ore concentrate could be increased from 80% to 95.72% to reach the acid grade fluorite index through the rational combination of new reagent such as sulfating water glass, aluminum sulfate, tannin extract and naphthenic acid as well as adopting the closed circuit flotation process of one-time rougher flotation and five-time concentration.

The influence of gas flow distribution on blast furnace smelting is important. After the blow-on of 3^# blast furnace of Baotou Steel for medium maintenance, the control interval of reasonable gas flow distribution of blast furnace is put forward based on the data analysis of upper and lower adjustments by taking economic indicators as reference so that the reasonable control of gas flow distribution is realized. As a result, the goals of improving utilization rate of gas and reducing coke ratio are reached so that the long-term stability and smooth operation of blast furnace are maintained.

In this article, the technology of smelting process for X80 submerged arc welding wire steel produced by Baotou Steel is discussed from such aspects as smelting conditions, deoxidation modes, refining slag system adjustment and protective pouring of casting machine. The control goals of low carbon, phosphorus and sulfur are achieved through process research and technical measures for each production process so that the high quality requirements of submerged arc welding wire steel for X80 pipeline of Baotou Steel are guaranteed.

The influencing factors of KR pre-desulfuration technology are analyzed and studied through the test of operation and technological parameters of KR desulfurization. The test results showed that the effects of consumption of desulfurization powder as well as stirring time and speed on the desulfurization rate of molten iron were obvious. Moreover, the parameters of KR desulfurization production technology are determined and the production technology is solidified, which could provide guarantee for stable production of variety steel.

In the paper, it is mainly elaborated a series of problems of Φ600 mm roughing mill since the new production line of bars was put into production in the work zone of strip steel of Long Products Plant of Baotou Steel. The pass, guide plate and tilting plate are remoulded aiming at the corresponding defects of roughing mill. The accident of seizing-up is reduced and production efficiency is improved through the systematic maintenance of Φ600 mm roughing mill so that the design capacity for production line of bars could be guaranteed to be reached smoothly.

The causes, internal and external factors of pipeline corrosion and damage are analyzed aiming at the operation situation of gaspipe network as well as the hidden danger of corrosion and leakage for gas pipeline of Baotou Steel. The corresponding method of plugging leakage accompanied with gas and pressure is pointedly adopted combining with the specific conditions of pipeline corrosion of different mediums to eliminate unsafe factors in operation of gaspipe network, ensure safe operation and normal gas transmission of network as well as safe and stable operation of gaspipe network system.

In this paper, the reasonable alloy composition system and smelting, rolling and heat treatment process routes are designed according to the performance requirements of high strength and toughness steel plate for square cabin of special off-road vehicle, the microstructure of produced high strength and toughness BT700E steel plate is tempered sorbite as well as well as the tensile, impact and cold bending properties are good. The BT700E steel plate has been tested for anti-explosion protective performance as well as there are no cracks on both of the whole protective cover of explosive parts and bending line after inspection, which could meet the protective requirements of protecting against 8 kg TNT explosives for special mine-resistant vehicle and user feedback is good.

The causes for longitudinal crack on high strength steel of wide and thick plate of Baotou Steel are found out through analyzing the chemical composition of high strength steel, water quantity and cone angle of crystallizer, casting powder and production organization combining with the casting machine and technological characteristics for wide plate of Baotou Steel. Moreover, such control measures as optimizing the production organization, properly increasing cone angle of crystallizer, decreasing water quantity of crystallizer and optimizing operation of changing ladle between heats are established so that the longitudinal crack on high strength steel is reduced obviously. The results showed that strict quality control measure was the key factor to eliminate longitudinal crack on high strength steel.

The development of beam steel 800L with the composition design of low carbon, microalloying of niobium, vanadium and titanium as well as controlled rolling and cooling process is carried out in the lab. Moreover, the chemical composition, heating and holding temperatures, rolling and cooling technologies are studied as well as the mechanical properties are tested and microstructure is analyzed. The results showed that the trial-produced 800L steel was with two-stage rolling after held at 1 250 ℃ and finishing temperature was set at 860 ℃, laminar cooling was carried out after rolling and finish cooling temperature was 600 ℃ so that the beam steel 800L with good mechanical properties was obtained as well as its yield strength, tensile strength and percentage elongation after fracture were 753 MPa, 845 MPa and 18.5% respectively as well as the 180° bending test was qualified.

A parts company stamps the parts of "dust cover of brake" and there is the situation that sheet is not suitable in the process of material switch. In this paper, the deteriorating trend of sheet is accurately expressed through two modes of contrast calculation, direction of performance adjustment is given through simulation analysis, friction coefficient is improved through increasing tensile value and optimizing surface micro-morphology so that the performances of subsequent products are improved and user feedback is good.