The stable operation of heavy duty mining truck is beneficial to safe production of mines. The failure rate of heavy duty mining truck in a mine is high and it is even higher in winter. It is found through analysis that the main causes are structural designs of accumulator and steering pump themselves for hydraulic system are not reasonable as well as control of mixture ratio of fuel to oil for engine is not accurate. The seal wear is reduced through changing single-point support to oriented multi-point support for piston of accumulator and adding unload groove; such problems as high pressure and temperature rise are solved as well as loss of parts is reduced through adding unloading valve on steering pump; temperatures of solidification point for different mixing ratios of 0^# and -35^# diesel are determined through experiments as well as auxiliary fuel tank is installed to choose different mixture ratios of fuel to oil and oil supply modes based on weather conditions. The failure rate of heavy duty mining truck is reduced through implementing the above measures.

The integrated control platform system of special steel requires to adopt industrial private cloud architecture. The upper monitoring system needs to establish virtual machines in the private cloud as well as install the Windows 7 operating system and WinCC7.0 SCADA. The private cloud server and switch in central control room are connected to the two core switches separately to establish redundant network structure in core layer. The systems in control layer and switch in central control room form ring network through respective switches, which takes into account the economical efficiency and security of network.

The rare earth inclusions in rare earth steel sample are separated from the matrix by electrolysis. The separations of rare earth sulfides, rare earth sulfur oxides and rare earth oxides are studied through different solvents, water bath time and chemical tests so that the scientific and reliable analytical method is established. The verification tests indicated that the results of precision for sample detection were good and relative standard deviation was less than 10%; for the comparative experiment of inductively coupled plasma mass spectrometry and spectrophotometry, detection results of the two methods were consistent. The analytical method could provide important technical supports for mechanism studies of rare earths in steel.

In the paper, the simultaneous determination for elements of vanadium, manganese, phosphorus and silicon in vanadium-carbon alloy is carried out with inductively coupled plasma-atomic emission spectrometry (ICP-AES), calibration curve is drawn with matrix matching method to eliminate the effects of matrix effects as well as instrument parameters are optimized. The precision experiment results showed that relative standard deviation (RSD, n = 11) for elements of vanadium, manganese, phosphorous and silicon was 0.5%~3.0%. The recovery rate experiment results showed that recovery rate was 95%~110% through adding standard solutions of different concentrations. The accuracy experiment results showed that the experimental results of each determination element were consistent with standard values, which could meet the requirements of detection method so that rapid and accurate determination for elements of vanadium, manganese phosphorus and silicon in vanadium-carbon alloy is realized.

In this paper, the current situations of implementation, advantages, challenges and optimization strategies for co-investment mechanism of employees in state-owned enterprises are discussed. Its connotation, characteristics and application situations in state-owned enterprises are elaborated through literature research and case analysis. It is found in the research that the co-investment mechanism of employees is with significant advantages in motivating employees, promoting enterprise innovation and optimizing governance structure, however, it is also facing such challenges as imperfect improvement and difficult risk control of co-investment mechanism in enterprises. In this paper, such suggestions as perfecting relevant systems of enterprises, optimizing system design as well as strengthening risk management and control are proposed, which could provide references for deepening reform of co-investment mechanism of employees in state-owned enterprises.

In this article, it is introduced the nitrogen content and oxygen concentration in heating furnace are reduced to inhibit NO_x to be generated through taking such specific measures as strictly implementing cooling system for rolling delay, improving hot charging rate and strengthening furnace body maintenance from the aspect of strengthening management of heating furnace as well as such means as taking minimum coefficient of excess air, refining air-fuel ratio, reasonably distributing thermal load, accurately controlling combustion temperature, prohibit negative pressure operations and increasing preheating temperature through analyzing the generation mechanism and influencing factors of NO_x based on current thought and methods of treatment for NO_x combining with working principle and characteristics of regenerative heating furnace. As a result, the accuracy of production operation is improved, generation of NO_x is reduced so that ultra low emission of NO_x is achieved.

In this paper, the whole process flow of development, production and applications for 500 m finished rail in iron and steel enterprises is studied. The large-scale, standardized and continuous production technological system of 500 m rail is established through production process control of series of rails as well as optimization, adjustment and control of joints combining with single system quality control. The production operation modes of 100 m and 500 m rails are realized so that the goals of the shortest transfer process of production materials as well as low carbon and green for long rails have been realized in the enterprise. The control goals that sulphur content of heavy rail steel≤0.005%, ratio of equiaxed crystal for continuous casting billet reaches 42% and segregation index of manganese for rail≤1.03 are realized through deep desulfurization of refining, tundish metallurgy and narrow composition control; dimensional deviation of rail height at both ends of head and tail for 100 m rail is ensured to be ≤0.40 mm as well as differences of high-low points at the ends are ≤0.20 mm based on high precision rolling technology of rail; joint quality is effectively improved and qualified rate of joint could reach over 99% combining with rail production quality improvement and welding process optimization.

In the paper, the rock and ore are divided into three main classes and five subclasses based on iron grade and data of perforating for production in Main Mine of Bayan Obo in recent years as well as distribution rules and space coupling characteristics of contents of F and S in various types of rock and ore are summarized. The research results showed that the main occurrence minerals of element F in Main Mine of Bayan Obo were fluorite and bastnaesite as well as main occurrence minerals of element S were pyrite, pyrrhotite and galena. In terms of distribution of contents of elements F and S, it generally shows the change rule of “increasing first and then decreasing” with the increase of iron grade of ore; in terms of space distribution, elements F and S are most closely related to iron ore, space distribution range of elements F and S is gradually decreased as well as overlapping area is gradually decreased and separated, which shows the distribution characteristic of “alternate zoning with variants” with the increase of contents of F and S.

The propagation model of shock gas is established by taking the shock gas induced by instability of goaf as research background as well as the change rules of propagation rate are analyzed with the laboratory test that simulates shock gas and numerical simulation method. The study results showed that the model of flow past body of shock gas consisted of stages of uniform motion and accelerated motion; the larger the falling height of roof of goaf, the smaller the proportion of duration of uniform motion stage and the larger the proportion of duration of accelerated motion stage. The study results could provide references for prevention and treatment of shock gas disaster induced by instability of goaf.

After the separation of iron and rare earth for ore in Main and East Mines of Bayan Obo, the content of Nb₂O₅ in rare earth flotation tailings is enriched from 0.14% to 0.19%. The bulk flotation is adopted to separate easy-floating minerals in advance so as to reduce the impacts of easy-floating minerals in desilting on subsequent niobium flotation as well as the combined process of flotation and magnetic separation that bulk flotation of tailings-selective flotation of sulfur-flotation of iron-niobium flotation of iron tailings-high intensity magnetic separation of niobium concentrate is adopted to separate niobium industrially aiming at the high content of easy-floating minerals as well as close paragenesis and inclusions of niobium minerals and iron minerals. The bulk flotation is carried out under the conditions that the proportion of size fraction of -0.043 mm for grind fineness is 90%, dosage of TD-V collecting agent is 1.0 kg/t and dosage of depressor, the sodium silicate is 2.0 kg/t, sulfur flotation is carried out under the condition that dosage of butyl xanthate is 1.4 kg/t, iron flotation is carried out under the conditions that dosage of ammonium fluosilicate is 8.5 kg/t and dosage of collecting agent, the SZ fatty acid sodium salts is 0.5 kg/t as well as niobium roughing is carried out under the condition that dosages of CMC, C_5-9 and alum are 1.2 kg/t, 2.2 kg/t and 0.72 kg/t respectively. The niobium concentrate of flotation with grade of Nb₂O₅ of 2.21% is obtained by adopting the niobium flotation process of one roughing and one concentration as well as the niobium concentrate with grade of Nb₂O₅ of 4.41% and sub-niobium concentrate with grade of Nb₂O₅ of 0.96% are obtained through high intensity magnetic separation of 1.7 T so that recovery rate of niobium metal is 34.85% with the combination process of flotation and magnetic separation.