In order to achieve effective logistics control for metallurgical waste slag, the intelligent management and control system is realized, in which such transportation and sale processes as contract, plan, clean transportation, weighing, confirmation of loading and unloading in stock ground as well as automatic transportation to outside of plant are integrated through the remote access and control technology, automatic license plate recognition technology with surveillance camera at guard room and development of App on cell phone. As a result, the loopholes in the processes of sales, transportation and measurement for metallurgical waste slag are eliminated as well as the cheating behaviors are completely eradicated so that the levels of measurement control and informatization management for enterprise are improved.

In order to improve the engineering construction quality and promote the construction efficiency of building engineering, construction teams need to reasonably apply digital technologies in engineering management process to meet the requirements of current era for engineering management. The feasible application strategies for digital technologies in engineering management could be formulated by analyzing the specific application values of digital management methods and application characteristics of digital technologies to promote effective reform and improvement of construction management, which makes the engineering management play a certain role in ensuring specific engineering construction process to reduce the probability of accidents so that the engineering construction could be completed as planned.

In the paper, the relations between such factors as the microstructure of rails, inclusions, excessive hydrogen and residual stress and Crack Length-Cycle curve are analyzed through the data and diagrams obtained by the tests based on the test of threshold value of crack expansion ΔK_th for U71Mn, U75V and U20Mn quenched rails as well as U75V test steel with the rare earth, lanthanum and cerium. Moreover, the effects of adding the rare earth, lanthanum alloy and cerium alloy into rails on crack growth of rails are analyzed, which could provide new means for analyzing the performances of rails and prolonging service life of rails.

The internal audit, as an important part of audit supervision, plays a role of fundamentality and source of self-regulation in the audit supervision system as well as has become the effective complement and extension of national audit. It is the significant problem faced by management layer and internal auditors of state-owned enterprises how to adapt to new circumstances, give play to the supervisory role of internal audit as well as establish the immune mechanism with self-perfection and healthy development within enterprises. In the paper, the practices and experiences of internal audit reform in enterprises are arranged and summarized from such aspects as establishment of auditing offices, construction of audit teams, analysis of auditing cases, audit rectification and achievement transformation of audit as well as the future development direction is pointed out.

The industry is the pillar industry of national economy. In the process of industrial production, its virtual simulation is carried out with the computer simulation technology, the running conditions of production line could be simulated by the simulation technology so that the rhythm of production and technological process are optimized as well as production efficiency and capacity are improved; the layout of production line, process arrangement and equipment configuration are optimized to improve production efficiency, reduce production costs and waste of resources. In the paper, the solutions for intelligent production line of rare earth oxides are designed with the computer virtual simulation technology by taking the intelligent manufacturing project for production line of rare earth products as example. It plays role in optimizing the technological process of intelligent manufacturing and layout of production line of rare earth oxides products. Moreover, the real scenarios of industrial production and virtual reality simulation are deeply integrated with the simulation technology so that customers could truly feel and understand the intelligent manufacturing process of production line of rare earth oxides.

In order to reduce the content of gangue minerals in iron concentrate, improve the grade of iron concentrate as well as reduce the consumptions of reagents and steam in the flotation process flow of iron, the magnetic separation with elutriation is added in the original process of Baoshan Mining Co. and the operation of a set of flotation system is reduced. The process of elutriation-flotation shows the good function of improving grade of iron as well as reducing contents of silicon, potassium and sodium. The grade of iron of iron concentrate reaches 67.07%, content of SiO₂ is 1.98%, content of K₂O and Na₂O is 0.172%, total operating productivity is 79.60% and recovery rate is 93.27%.

In the paper, the production practices on increasing production and reducing fuel ratio for 7^# blast furnace of Baotou Steel are summarized. In September 2022, the average daily output reached 9 370.7 t/d, utilization coefficient of effective volume for blast furnace was 2.258 t/m³·d and fuel ratio was reduced to 548 kg/t through taking a series of effective measures such as strengthening the management of crude fuel, increasing wind-warm syndrome, furnace top pressure, oxygen enrichment rate, batch weight of ore and coke ratio of ore into furnace as well as optimizing the charging system, reducing the amount of central coke and improving gas utilization rate.

The stability of moisture of mixture is directly related to the granulation effect of sintering and heat transfer rate in sintering process so that the quality index of sinter is affected. It is found out that the main factors influencing stability of moisture of mixture include the moisture of iron charge, blending process as well as addition of fly ash and cold return fine through the comprehensive analysis on moisture of each crude fuel for 500 m² sintering machine of Baotou Steel and factors influencing moisture of mixture. The stability of moisture of mixture is obviously improved and black pipes at sintering machine tail are reduced through producing process monitor and control of moisture of each iron charge, adjusting and optimizing production technologies as well as formulating corresponding measures such as production and operation methods and technical improvement of equipment so that such indexes as the qualified rate of alkalinity for finished sinter, stability of FeO, qualified rates of drum strength and average particle size are with year-on-year increase.

In this paper, the effects of rare earth on the quality, metallurgical performances and mineral composition of sinter are systematically studied with sinter cup as well as the occurrence states of rare earth in different minerals of sinter are analyzed with scanning electron microscope and energy spectrum. The results showed that the sinter product ratio, utilization coefficient and drum strength tended to be increased first and then decreased, reducibility and low-temperature reduction degradation index of sinter tended to be improved first and then deteriorated, melting range was widened as well as the amount of formation for calcium ferrite in the mineral composition of sinter tended to be decreased with the proportion of rare earth increased. During the sintering process, the rare earth is into hematite, calcium ferrite and glass phase as well as it exists as columnar rare earth mineral in glass phase.

In order to expand the coal resources for coal injection of Baotou Steel and reduce the fuel cost of blast furnace injection, the laboratory study on applying hydrogenated semi-coke with destructive distillation in blast furnace injection is carried out by Baotou Steel. The results showed that the hydrogenated semi-coke with destructive distillation was high quality fuel of blast furnace injection with such characteristics as low moisture, volatiles and sulfur content as well as high fixed carbon, however, its bulk density was much smaller than that of mixed pulverized coal as well as its combustion rate was better than that of existing mixed pulverized coal and without explosiveness so that its combustion and safety performances could meet the safety requirements of blast furnace injection.