Light-weight spinel refractories were prepared by solid phase sintering method with fused spinel fine powder，sintered magnesia powder and hollow magnesia alumina spinel balls as main raw materials. The effects of magnesia powder and hollow magnesia spinel balls on phase composition，microstructure，compressive strength and thermal conductivity of refractories were studied. The results showed that the introduction of magnesia powder（less than 5%）promoted the cambination of hollow balls and surrounding particals due to the solid dissolve in spinel and the formation of secondary spinel between hollow ball and spinel powder particles. Increasing the content of magnesia powder promoted the sintering，compactness and compressive strength of refractories. Addition of magnesia powder below 5% was conductive to obtain light-weight spinel refractories with the enhanced compressive strength (22.8 ～ 27.3 MPa)，the decreased size of pores and thermal conductivity [200 ～ 1 000 ℃，0.256 ～ 0.524 W/(m•K)].

China will implement the double-carbon goal of “peak carbon dioxide emissions by 2030 and carbon neutrality by 2060”. High-temperature industries such as steel are the key areas of energy conservation and carbon reduction in China，and refractories are the important basic materials to support the implementation of new processes and technologies in high-temperature industries such as steel，which will also face a series of opportunities and challenges. In order to meet the green production of steel and other high-temperature industries and the carbon reduction requirements of refractory enterprises，it is urgent for refractories to realize green production.

Talc [Mg3Si4O10(OH)2] is a layered magnesium silicate mineral with stable chemical properties and good mechanical properties. The general situation of talc resources in China and the application research progress of talc and modified talc in the sewage treatment，ceramics， coatings，medicine，plastics and other industries in recent years are reviewed. The problems existing in the development and utilization of talc are analyzed，and the development direction and prospect of talc are prospected，so as to provide reference for the development of talc industry in China.

In this paper, the raw material formula of magnesia spinel non-fired brick is improved, and its physical and chemical indexes are determined. By analyzing the erosion of residual brick of RH furnace by SEM, it is found that the magnesia spinel non-fired brick has achieved good results in RH furnace trough, circulation pipe and RH snorkel, and its service life has exceeded that of magnesia chrome brick in smelting some steel grades. With the continuous optimization of magnesia spinel non-fired brick scheme and the scarcity of chromium ore in the domestic environment, the available magnesium spinel non-fired brick gradually replaces magnesia-chromium brick.

This paper introduces the all-carbon matrix DMT-20/T MgO-C brick for UHP electric furnace, which is made by adopting special grain size gradation and production method and increasing the amount of graphite. This brick has good resistance to oxidation, deterioration of tissue structure and erosion. It has been used in the hot area and slag line of 50 t UHP electric furnace in FS-DS steel plant, and its service life reaches 573 heats, which is 63.7% higher than that of 350 heats with the highest service life in the factory in the past, and its damage rate is 18% lower than that of our company's DMT-18A MgO-C brick. The results of microstructure study of residual brick show that the thickness of decarburized layer of all-carbon matrix DMT-20/T MgO-C brick is only 0.2～0.3 times that of traditional DMT-18A MgO-C brick, and there is no structure deterioration in the matrix between the decarburized layer and the original brick layer. This can ensure that the product has high durability and is suitable for use in UHP electric furnace.

This paper introduces the problems existing in the initial operation process of a high purity magnesia production line in Shanxi. After the on-site analysis, the solution was put forward, and the problem was solved after the transformation.

The trough of the ironmaking plant plays a role in circulating molten iron during the tapping process of the blast furnace. It is very important for the daily maintenance and repair of the refractories of the trough in the normal production process. At the same time，the furnace must be shut down for several days when the production of the blast furnace is limited by environmental protection and abnormal production. In this state，the maintenance of the refractories in the trough and the protection during the shutdown are related to the subsequent safe operation and cost reduction of the refractories in the trough. This paper summarizes the experience of some daily operation points in the process of maintenance of trough，which can be used for reference by peers.

Clay bonded SiC ceramic materials were prepared with clay and SiC fine powder as main raw materials. The effects of sintering atmosphere (air, buried carbon and nitrogen) on its phase composition, microstructure, bulk density, apparent porosity, compressive strength and other properties were studied. The results show that the main components of the samples burned in three kinds of atmosphere are SiC and glass phase, but a small amount of cristobalite and silicon oxynitride are formed in the samples burned in air and nitrogen atmosphere respectively；The high partial pressure of O2 and CO will have an adverse effect on the material. Large area "bubbling" phenomenon appears on the surface of the sample sintered in air atmosphere, and the uniformity of the macro and micro structure of the material is not good; The sintering property and strength of the samples sintered in carbon atmosphere are the worst and the lowest; The samples sintered in nitrogen atmosphere have uniform structure, the highest strength and the best comprehensive properties.

This paper introduced that the applicaiton of raw material graded charge technology in TGS lime kiln and Maerz kiln，which successfully cancels the original water washing process of Maerz kiln，solves the water pollution problem，improves the utilization rate of raw materials， improves the furnace condition and increases the output.

Calcium carbide slag is a kind of industrial waste slag mainly composed of calcium hydroxide，and it features strong alkalinity，a large output and is easy to cause environmental hazards. To be utilized as a resource，calcium carbide slag is calcined to obtain active lime as it is an important auxiliary raw material for steelmaking or other industries instead of natural active lime. The physical phase and composition of calcium carbide slag before and after calcination are examined with XRF and XRD to determine the feasibility of converting calcium carbide slag into active lime. The physical and chemical changes that occur during the heating process of calcium carbide slag are investigated via differential thermal analysis. By setting different calcination temperatures and duration，the optimum calcination regime to obtain the lime with the best activity is determined. The study unveils that the lime obtained by calcining carbide slag at 900 ℃ for 1.5 h has the highest activity.

The lime rotary kiln has high heat consumption and high cost，and the specific influencing factors are found out through the production site．By optimizing the production process and recycling resources，the production capacity is increased，the production cost is reduced， and remarkable economic effects are achieved.

In this paper，dry-discharged and wet-discharged calcium carbide slag were used as raw materials to prepare sorbents suitable for dry desulfurization of circulating fluidized beds， which were characterized by indicators such as TGA，SEM and BET etc．The results show that it is not only of good economic benefit，but also of good social and political benefit to turn calcium carbide slag into treasure.

The existing standards for quality inspection sampling and sample preparation of limestone bulk products are all artificial methods. Artificial methods are time-consuming, laborious and easily disturbed by human factors.We changed manual sampling to crane grab sampling, manual screening to mechanical screening, and determined the appropriate sampling and sample preparation parameters for the test. The results show that the sample inspection results obtained by the improved method are basically consistent with the manual method, but the improved method has shorter inspection time and can eliminate the influence of human factors. It can help to control the quality of purchased limestone in time and strictly, and provide timely data support for the stable running of production process.