“Emission standard of air pollutants for magnesia refractory industry”(DB21/3011-2018) is the first mandatory air pollutant emission standard in Liaoning province and the first mandatory emission standard in the industry.This paper introduces the background and basis of the standard preparation, and analyzes the standard execution time,emission limits and other relevant provisions,which is convenient for magnesium refractory enterprises,environmental protection enterprise and environmental authorities to  accurately grasp the main technical contents of the standard and actively promote the implementation of the standard.

Unfired dense Al₂O₃-MgO bricks for steel ladle were prepared with corundum,spinel,alumina micro powder and magnesia as main raw materials,magnesium aluminate gel as binder.The properties of the brick were studied and compared with the existing steel ladle prefabricated brick.The results show that the mechanical pressed dense brick exhibits superior strength,apparent porosity,thermal shock resistance,erosion resistance and thermal expansion.It can be predicted that the application effect on the steel ladle will be better,which conforms to the concept of energy saving,environmental protection and high efficiency,and becoms one of the development trends of carbon-free refractories for steel ladle.

Anhydrous tap-hole mix samples were selected from different large blast furnaces of five iron works to investigate the preparation method.The firing temperature before preparation and the moulding pressure for the anhydrous tap-hole mix were determined.The necessity of carbonization before testing the high-temperature performance testing of anhydrous tap-hole mix was discussed.The carbonization temperature,time and atmosphere were determined by analyzing the mass loss rate,flexural strength at room temperature,bulk density and apparent porosity of the samples after heat treatment at different temperatures.

Different types of anti-explosion fiber used for castables are selected as samples to study and analyze the fiber structure,dry state and water-solubility at different temperatures.The result shows that in drying and heating process,the melting temperatures of 6# and 7# samples are the lowest,as low as below 130 ℃;the carbonation of 5# sample has begun before hardening at 250 ℃;in room temperature water,the dispersion effect of 5# sample is the best;in boiling water,5# sample completely dissolves into water,6# and 7# samples soften and contract into clusters,and the other samples arrange irregularly and gather and float on the water surface.

Carbon-free skimming cones of converter were prepared with used high alumina bricks,slag steel and iron grit as main starting materials,high alumina cement as binder.The effects of refractory grain,slag steel and iron grit and light burned magnesia on the performance of skimming cones of converter were studied and analyzed.More than 10 000 novel carbon-free skimming cones have been successfully applied to 120 t carbon steel converter,110 t stainless steel dephosphorization converter and 50 t carbon steel converter of Jiu steel.The success rate of skimming was over 99% and the application effect was good.Metallurgical solid waste has been replaced more than 80% of high quality raw materials in skimming cone of converter,greatly reduced the cost of iron and steel smelting,and reduced the discharge of solid waste,with good economic and social benefits.

Multiple hole plug (MHP) was one of the main type of converter gas plug and widely used in combined blowing converter.The manufacturing process,wear mechanism,service life influencing factors,such as the materials and structure of the MHP,installing,steel-making technology,maintenance were introduced in this paper.

Silicon nitride combined with silicon carbide brick production widely uses the reaction sintering method,namely the elemental silicon powder mixed with silicon carbide sintered under nitrogen atmosphere and the production of silicon nitride.In the production process,the forming bulk density has an important influence on the nitridation reaction and the properties of the brick.This paper mainly studies the influence of forming bulk density on physical properties,chemical composition and electrolyte erosion resistance of Si3N4 bonded silicon carbide bricks.The results show that the physical properties and electrolyte erosion resistance of the samples improve with the increase of bulk density,while the content of Si3N4 in the samples decreases.

This paper analyses the effects of calcining temperature,calcining zone,calcining time,air distribution coefficient,lime stone physical and chemical properties and fuel value on production of high quality metallurgical lime in Maerz kiln with nature gas as fuel.Our company proposes control requirements and optimizes the process and stables product quality.

This paper introduces the design parameters and characteristics of the environmentally friendly ultra-low emission process of tail gas dust removal and desulfurization and denitration,which is an effective environmental protection technology for reaching emission standards in the refractory production industry.