The rare earths are important elements for improving the properties of iron and steel material. In recent years, there are some important progresses for the researches of electrical steel containing the rare earth. In this paper, the functions and research progresses of rare earth in electrical steel are discussed. The influencing rules of rare earth on inclusions, texture, microstructure and properties of non-oriented silicon steel and oriented silicon steel are summarized respectively. It is one of the important ways to add rare earth into electrical steel for improving its performances, which is the important direction of the development of electrical steel in the future.

The whole process from the occurrence of cracks to slumping of 4^# slip mass in 1 626 m south D area of main stope of Bayan Obo Iron Mine was monitored. The formation mechanism and evolving regularity were analyzed and summarized so that the slumping time was predicted timely and accurately. As a result, the safe production around and at lower step was effectively guided, the damages of equipment and personnel when slip mass caving were avoided and the effective treatment scheme after slumping was put forward simultaneously, which were with significant meanings to the side slope management of the mine.

Bayan Obo ore deposit is an ultra large multi-metal ore deposit with such as Fe, rare earth and Nb. In recent years, the deep prospection has been carried out in the main east mine and the deepest drill hole designed is up to 1 700 m. Part of stratum (especially the part of ore reception and removal) is with such complicated features as fragmentation, leakage, collapse and chip off-falling. In order to avoid such accidents as sticking of tool, tools truck or obsolescence of drill hole caused by instability of drill hole, the low (no) solid drilling mud, anti-deflection drill + anti-deflection technology with packed hole assembly and the relative technical measures are applied so that the drilling is smooth, the construction quality and efficiency are good, which could provide the technical assurance measures and experiences for the construction of main mine in future.

Due to the changes of the industry situations, mining enterprises face many difficulties in the production organization, so the production and equipment efficiency is improved and the consumption is reduced with the lean production management methods in practical applications as well as taking the innovations as the power and taking the projects as the central tasks by constructing the lean production management system of enterprises and combining with the actual productions. Moreover, such problems as the existing bottleneck restriction, inventory, equipment failures and blocked information in the process are eliminated by using a variety of innovative approaches and tools to carry out the lean production management and construct lean production management system to help the healthy development of enterprises.

In 2016, the rate for bending and damage of tuyere of large blast furnace of Baotou Steel achieved 70%, which became the main restraining factor for intensified smelting of blast furnace. In this paper, it is introduced the bending and damage of tuyere were eliminated through such methods as adjusting the lower blast parameters, controlling the middle heating load and optimizing upper charging system to maintain the reasonable operational furnace profile. The results showed that the bending and damage of tuyere could be effectively eliminated by controlling reasonable operational furnace profile.

In Coke Chemical Engineering Branch Co. of Inner Mongolia Baotou Steel Union Co., Ltd., there are four 6-m coke ovens heated with blast furnace gas. Due to the production technology of blast furnace, the temperature fluctuation of blast furnace gas is bigger, the adverse effects of blast furnace gas temperature increased from about 35 ℃ to over 45 ℃ on energy consumption of processes for coke ovens, heating equipment, gas flowing rate and thermal losses of oven body in the production are mainly analyzed.

In this paper, the solutions for the existing problems of configuration of measuring equipment, metrological confirmation of verification or calibration, monitoring of measurement process and formulating interval of periodical confirmation for non mandatory verification measuring equipment are proposed aiming at the existing prominent problems of weak links in the present metrological management of company in product certification as well as the significance of metrological management for the product quality assurance of enterprise. Moreover, the risk for inaccuracy of metrical data is prevented and controlled to realize the sustainable development of enterprise.

The gelatinous layer index of coking coal is with the important guiding significance and consideration value for guiding coal blending for coking and predicting coke strength. In the paper, the main factors affecting the data accuracy are determined and the implementation measures for testing data accuracy are put forward through analyzing such influence factors as coal sample preparation, testing equipment and detection process.

The phosphorus content in phosphating wastewater generated in the coupling production line of a steel tube company was higher and the effect of original coagulation treatment process was not good, so the technical transformation was necessary. The experiment was with three stage coagulating sedimentation and dephosphorization filter unit for adsorption filtration of high concentration phosphorus wastewater. The results showed that the TP of effluent discharging after treatment is nearly completely removed (lower than the national primary standard for comprehensive wastewater discharge 0.5 mg/l) for the phosphating waste liquid with the TP concentration of 5 000~15 000 mg/l and the phosphating wastewater with the TP concentration of 100~200 mg/l as well as the removal rate of TP can be stabilized at about 99%.

In the paper, some basic characteristics of rare earth in Bayan Obo Mine and the present situation of grading rare earth concentrate in North Rare Earth High-tech Co., Ltd. are introduced; the concentration, grade and granularity of overflow mine obtained by the first section permanent magnetic tailings of Bayan Obo Magnetite after stage-grinding and stage-separating in Dressing Plant of Baotou Steel with swirler are analyzed; the technical route and technical index for grading high grade rare earth concentrate with overflow mine of swirler are established, which lay a foundation for the smooth development of industrial test. The industrial grading for overflow of swirler has been realized in the Rare Earth Dressing Plant with the original production technology.

The chemical pickling is intended to be used for iron concentrate slurry pipeline descaling, but it may cause the pipeline leakage. In the paper, the type, concentration, reaction time and the influence degree on iron concentrate slurry pipeline of acid were determined through the scale quality analysis, scale dissolution experiment, experiment for test block of pipeline material, weld experiment and tube test. The experimental results showed that the hydrochloric acid pickling was safe.

In this paper, it is described that when rolling the H630 mm × 200 mm × 15 mm × 20 mm H beam with Q420NQR1 produced by Baotou Steel, there are such situations as abnormal microstructure and low temperature impact toughness fluctuation. The abnormal microstructure are eliminated, homogeneity of microstructure is greatly improved and low temperature impact toughness fluctuation is effectively controlled through optimizing the composition and rolling process.

In the article, it is discussed the technology for producing the bridge steel products with the yield ratio no more than 0.84 is found out with the advanced steelmaking and steel rolling equipment of Rare Earth Steel Plate Plant of Baotou Steel through adopting the composition design of medium carbon + high manganese + microalloying as well as reasonable technology and measure of controlled rolling and controlled cooling. As a result, the bridge steel with such characteristics as good formability, weldability and low temperature toughness could be produced with volume production.

At the initial stage of producing cold rolled low carbon steel SPCC with the continuous annealing cold rolling production line of Baotou Steel, there were the problems that the yield strength was higher and the yield platform. In the paper, the effect of dislocation pinning is achieved through reducing the content of [N] in the chemical components of SPCC aiming at the above problems. In view of the differences between continuous annealing and cover annealing, the performance optimization for cold rolled steel SPCC with continuous annealing is finally realized through increasing the hot rolling coiling temperature of strip steel from 650 ℃ to 710 ℃ and controlling the precipitated phases of carbides and nitrides for strip steel after hot rolling to reduce the yield strength and eliminate yield platform.

In the paper, the basic reasons for the qualified rate for negative deviation of screw-thread steel are determined and the control level of basic reasons is established by taking φ25 mm screw-thread steel as an example, combining with the idea of six sigma using DMAIC steps to solve problems and supporting by data. As a result, the qualified rate for negative deviation of screw-thread steel is increased from 65.6% to 91.36% in order to better adapt to the delivery of screw-thread steel by theoretical weight, increase product profit and reduce costs of per ton of steel.

There was obvious center porosity in the production of Q345B round continuous casting billet, so the gas content and hot acid of continuous casting billet were tested as well as the solidification process of continuous casting billet was analyzed. The results indicated that the lower strength of mold electromagnetic stirring and final electromagnetic stirring caused fewer nuclear of grain, the lower strength of secondary cooling caused the full growth of grains, the grains piled up at the end of liquid core and divided the molten steel, the volume of molten steel in enclosed cavity was shrinked in the solidification process and formed small contraction cavity. The relative improvement measures are put forward based on this.

In the paper, the characteristics and production of H08A wire rod for arc welding are introduced. The requirements for chemical composition of steel grade are achieved by studying the control for low carbon and low silicon content of H08A steel for welding electrode, especially controlling the low silicon content; the trouble-free operations of continuous casting process is realized through studying the pourability, especially controlling the Ca/Al ratio; the billet quality is accepted through control study for the defect of rimhole of billet, especially controlling the oxygen content; the ideal microstructure of pearlite and ferrite is obtained through studying controlled cooling process of rolling. Finally, the batch industrial trial production of H08A is realized and all indicators could meet the requirements of users.

The effects of layer thickness of wind turbine blade with composite material on performance of blade are obvious and the effects of fibre cloth with different angles on structure property of blade are different since it occupies different layer thickness. The characteristics and law on effects of layer thickness of unidirectional fiber fabric on the performance of fan blade are investigated by taking the genetic algorithm as the optimization algorithm and taking a 1.5 MW mature fan blade as the research model. According to the structural features of wind turbine blade, the appropriate modeling method is determined as well as the objective function, genetic operators (selection, crossing and variation) suitable for the asymmetric laminate are found out. On this basis, the optimal solution of the layer thickness for fan blade laid with different fiber cloth is obtained.

The production practices show that the 12Cr1MoVG steel tube with medium thick wall is easily to be with lower tensile strength, low impact toughness value, uneven even unqualified impact value after the treatment of "normalizing + tempering", the tensile strength could be over the upper limit due to the influence of cooling speed after normalizing if with the treatment of complete "quenching + tempering". In the paper, it is introduced the overall performances of 12Cr1MoVG steel tube are excellent by adopting the method of intermittent" quenching + tempering" with the existing quenching equipment of Baotou Steel.

In the paper, it is introduced the content of silicon carbide in warming agent was determined with the combustion gas volumetric method by burning the sample at about 800 ℃ to remove the free carbon, dissolving carbonate with acid, filtration and washing. The determination conditions such as the temperatures of starting decomposition and complete decomposition for silicon carbide, preheating time and selection of sample weights are discussed as well as the optimum working conditions are found out. The measurement range of content of silicon carbide with this method was 1.00%~45.00%. 11 times of determination were carried out with 4 types of warming agent samples and the relative standard deviation (RSD) were 0.952%, 0.446%, 0.590% and 0.490% respectively. Compared with other methods, the results were the same.

The thermal performance is an important index for coal injection production technology of large blast furnace. In order to quickly and accurately analyze the reactivity and post-reaction strength of coke, the effects of cold charge and hot charge of coke sample on analyzing speed were studied. The comparison results of experiment showed that there were not great differences between the thermal performance analysis result of charging sample after the furnace body was cooling from 1 100 ℃ for 2 hours and that of charging sample when the furnace body temperature was at room temperature, which could meet the requirements of quickly analyzing sample and guiding the production on site.

In the paper, the technological process of modified pitch is introduced. The forms and causes of damages for reaction kettle are summarized through tracking the maintenance and operation of reaction kettle for many years. Moreover, the damages of reaction kettle are retarded and its service life is prolonged through transforming and strengthening the operations so that the accidents are avoided, equipment maintenance costs are reduced and composite economic results are improved.

In order to reduce the energy consumption and production costs of enterprise, the energy saving technology of speed control device with wrapping connector driving of permanent magnet eddy is applied on the dust-removing fan for steel rolling. As a result, the speed control of dust-removing fan can be realized with the condition of meeting the requirements of production technology so that the dust-removing fan is operated efficiently and a lot of electric energy is saved.

In the paper, the 10-year operating experiences for desalting water station of Coking Plant are summarized. The common problems and treatment for reverse osmosis equipment are discussed combining with the on-site situations and operating data for reverse osmosis membrane and components of desalting water station. The method for judging the pollution of reverse osmosis membrane and main points of chemical cleaning are mainly proposed as well as the reasonable solutions for the problems and failures of pipeline and accessories are found out.

The ammonia distillation system in Coking Plant is studied with the idea and tool of six sigma management as well as its typical improved mode-DMAIC. The operating parameters affecting the stability of ammonia distillation system are found out and the mathematical model is established to determine the range of the parametric optimal solution so that the scientific control of operations is realized, the stability of ammonia distillation system is improved and the economic benefits are created.