After years of operation, there are such problems for the crushing system in submontane dressing area of Baoshan Mining Co. as large number of equipment, low technical level and high maintenance costs. The factors affecting crushing operation indexes are found out through investigating and analyzing the current situation of existing crushing technology. The existing crushing circuit is transformed, the original crushing circuit is changed from “one closed circuit each three sections” to “one closed circuit each two sections”, add HP800 fine crusher to realize the matching running of two types of crushers and carry out the size optimization of sieve plate. The particle size of entering grinder is greatly reduced after the transformation, which creates favorable conditions for subsequent grinding and separation operations, the number of equipment as well as workload of equipment maintenance and inspection are reduced so that the comprehensive benefit of RMB 8.54 million yuan per year can be created.

In the paper, the transformation plan of increasing four sub lines in the area of car dumper inside station is proposed based on the weak transportation organization as well as study of capacity expansion and transformation of station aiming at the problem that the holding volume of cargo trains in railways bureau is so great that the lines inside rare earth steel station are limited. The effect of limited lines on efficiency of fetching and delivering train is relieved, traffic congestion inside plant is avoided as well as unloading capacity of goods allocation is improved so that the unloading of raw materials and productions are further ensured.

The effect of no visible smoke dust is achieved through deeply analyzing the more serious emission of smoke dust after transform the unorganized emission of 1^# and 2^# coke ovens of Baotou Steel Qinghua Coal Chemical Engineering Co., Ltd. as well as transforming equipment and facilities of coal car and relevant equipment of gas export system, which is with a certain reference value to transform unorganized emission of tamping coke oven as well as control fugitive emission of smoke dust in the coaling process of tamping coke oven.

The waste emulsion is the oily wastewater in high concentration discharged in steel rolling process and the key of treatment is demulsification. In this paper, the suitable demulsification methods are selected through experimental study as well as the experimental conditions of electrooxidation demulsification and chemical flocculation demulsification are selected. The results showed that the most suitable demulsification method was electrooxidation, its optimum current range was 2.0~3.8 A and optimum voltage range was 140~200 V; the optimum coagulant for chemical flocculation demulsification was polyaluminum chloride. When the quantity added to is 1.5 g/L and pH value is adjusted to 7~9, the chemical oxygen demand (COD) in waste emulsion reduces to less than 8 000 mg/L, oil content reduces to less than 1 000 mg/L and suspended solids reduces to less than 1 500 mg/L.

In the paper, the scheme of establishing a self diagnosis model for high speed rolling bearing is proposed considering the complexity of rolling bearing fault diagnosis and combining with the difficulties of rolling bearing fault diagnosis for equipment on site. The original vibration signal of rolling bearing for high speed gear box is decomposed using the wavelet packet, then frequency domain signals in different frequency bands in decomposed original vibration signal are reconstructed and the characteristics of shock pulse energy for rolling bearing fault of reconstructed frequency domain signals are extracted respectively. The extraction of characteristics for rolling bearing fault of high speed gear box is realized and they are used for establishing the self diagnosis model for high speed rolling bearing through comparing the characteristics of impact energy for rolling bearing extracted from each frequency band after reconstruction as well as extracting frequency band signals sensitive to energy changes aiming at different types of rolling bearings.

In this paper, a new-type accurate online measurement system of quantity of dry ore in pulp pipeline is introduced. The system is with the diaphragm pump as pulp conveying power and measuring equipment of pulp volume, pulp density is measured with γ-densitometer and grade of iron concentrate is with manual measurement, quantities of dry ore and backwater in pulp are calculated accurately with mathematical model; various data are processed automatically with information technology and results are published through the server of settlement report. Meanwhile, an automatic online calibration system is designed and manufactured to calibrate the calculated values regularly.

The material characteristics of seamless pipe for 850 MPa drill pipe of rotary drilling rig manufactured by Baotou Steel Tube Co., Ltd. such as mechanical properties, microstructure, ductile-brittle transition temperature, torsional strength and bending fatigue are tested and analyzed. The results showed that its such technical indexes as the mechanical properties, content of nonmetallic inclusions, grades of grain size and banded segregation could all satisfy the requirements of applying 850 MPa high strength and high toughness drill pipe of rotary drilling rig. Moreover, it is with such advantages as low ductile-brittle transition temperature, high torsional strength and good resistance to bending fatigue.

In this paper, the dimensional changes of austenite grain for X80 pipeline steel with such conditions as different heating temperatures and heating times are studied with the thermal simulation method. The results showed that the austenite grain coarsening was obvious, which was from the minimum, about 35 μm to about 120 μm with the increase of heating temperature and soaking time; but if the soaking time was shorter (1 min), the austenite grain size still remained within 80 μm even if it was heated at 1 280 ℃, which showed the essence of fine grained steel. As a result, the mathematic model of austenite grain growth for X80 pipeline steel was obtained by the regression of experimental data, which could provide basis for industrial production.

In this paper, the causes of cracks are analyzed with the macro morphological observation, chemical composition analysis, metallographic microstructure inspection, scanning electron microscopy and energy spectrum analysis aiming at the surface cracks of H beam web of a large domestic steel plant. The results showed that there was decarburization in the microstructure near cracks as well as there were secondary oxide particles containing silicon and manganese and the characteristic element sodium near matrix, which indicate that the cracks are generated during continuous casting of casting blank and finally formed on the surface of web.

The 550 MPa grade hot rolled axle housing test steel is rolled in laboratory with the design of medium carbon content+micro alloy Nb and Ti as well as controlled rolling and controlled cooling process. The results showed that the effects of adding moderate rare earth Ce into test steel on its microstructure and strength were not obvious, rare earth Ce reduced the grade of inclusion (class B) in test steel, low temperature impact energy of test steel with rare earth was obviously better than that of test steel without rare earth and fatigue property of axle housing test steel was improved by rare earth Ce.