Based on the present situation of production consumption and equipment development of metallurgical lime industry,the influence of “two carbon” target on metallurgical lime industry in China is analyzed.

In recent years,high-entropy alloys have developed many systems,and some of them have been applied.High-entropy ceramics is another important breakthrough of high-entropy concept after high-entropy alloy,it has developed steadily.High-entropy ceramics usually refer to multi-principal components solid solution formed by five or more ceramic components,and perform excellent mechanical,thermal,electrical and magnetic properties,which is of great application value.This review described the high-entropy ceramics research progress at home and abroad,and look forward to the future development.

Referring to relevant building materials industry standards and building lime test methods,the calculation methods of the lime underburing rate,the lime overburning rate,the lime underbuning and overburning rate are put forward.It has certain reference value for evaluating the calcining level and quality of lime and accelerating the process of promoting lime complete sets of technical equipment and process to high yield and low energy consumption.

MgO-SiO2-H2O based Al2O3-MgO castables have been prepared with 86% Al2O3 homogenized bauxite and 88% Al2O3 down-draft kiln bauxite as aggregates,respectively.The slag resistance of the castable specimens was investigated by a dynamic testing method via an induction furnace,and the results were studied by SEM,EDS and FactSage 6.2 thermodynamic modeling. The results show that the slag penetration resistance of castable with 88% Al2O3 down-draft kiln bauxite is a little better than the castable with 86% Al2O3 homogenized bauxite,and there is not much difference on slag resistance between the two castables;Cracks were formed at the aggregate-matrix interface near the hot face after the corrosion test,which adversely affects the slag resistance of the sample; After the above two castables respectively reacted with the slag,corundum,composite spinel,CA6,C2AS and CAS2 were coexsited.

The steel rolling heating furnace refractory needs to be dried after maintenance to ensure that the refractory will not crack and collapse during the subsequent high temperature process.In this paper, the processes of refractory drying in steel rolling  heating furnace with firewood and gas are described and summarized.At the same time, the overhaul and drying curves are formulated according to the condition of refractory maintenance, and the attention details in the drying process are summarized.Good practical results are obtained.

Copper slag is a kind of high-silicon and high-iron industrial waste produced in the process of copper smelting and zinc hydrometallutgy.It has many valuable components and it is a potential secondary resource.Based on the latest research progress at home and abroad in recent years,the extraction and recovery of valuable components from copper slag,including copper dilution recovery,iron recovery and recovery of other valuable components have been introduced.At the same time,the progress of preparing glass ceramic matericals,building materials and other high value-added products with copper slag is reviewed,the utilization status of copper slag at present is summarized,the existing problems are pointed out,and the application prospect is forecasted.

This paper introduces the operation process of ignition and heating-up for the Maerz kiln,analyzes the common problems in the furnace,and puts forward some solutions and corresponding optimization measures to ensure the smooth running of the kiln.

High-calcium magnesite is used as raw material to produce high-calcium fused magnesia through electric melting furnace.High calcium fused magnesia and MgO-CaO clinker are used as raw materials.After crushing,sieving,batching,mixing and other processes by hydraulic press under pressure of 2 500 t, MgO-CaO green brick is made.Then by firing the green brick at the temperature of 1 580 ℃ in the tunnel kiln,a special MgO-CaO brick is obtained.The fired brick has high volume density,high modulus of rupture and cold crushing strength,good thermal shock stability,low impurity content,good erosion resistance and strong scour resistance.The anti-spalling behavior and anti-slag permeability of MgO-CaO brick are better than the existing ones.The service life of the fired brick in stainless steel kiln is increased by 20%.

Sulphide ore,laterite nickel ore and nickel-manganese nodules on the seabed are three main types of nickel resources in the world.However,nickel-manganese nodules on the seabed are difficult to exploit and the sulphide ore resources are also depleted.The extraction of nickel from laterite nickel ore has become an important research direction.Combined with the research results of the treatment processes of lateritic nickel ore in recent years,the pyrometallurgy (small blast furnace smelting process and RKEF process,etc.),hydrometallurgy (normal pressure acid leaching,pressure acid leaching,etc.),combined hydro-pyrometallurgical process (reduction roasting-magnetic separation,etc.) are emphatically introduced in this paper,and their development trends are also prospected.

This paper discusses the technical characteristics of the sleeve kiln,and sums up the advantages of the sleeve kiln by comparing it with other kiln types,such as the raw materials with  a wide range of particle size,fuel adaptability,high equipment operating rate,simple operation and easy maintenance,low energy consumption,covering a small area,high degree of automation,high lime activity.Through the technical innovation,the sleeve kiln has gradually developed into one of the mainstream kiln types of lime production,and has a broad development prospect.

In order to further improve the performance of Al2O3-SiC-C iron ditch castable,the iron ditch castable was prepared with super bauxite,brown corundum,SiC,Al2O3 micropowder,white corundum,silica micropowder,silica powder(SiO2>97%) and Si3N4 powder as main materials,and high alumina cement as binder.The effect of Si3N4 content on the performance of iron ditch castable was studied.The results show that the castable with Si3N4 has better mechanical properties,thermal shock resistance and oxidation resistance at high temperature.On the other hand,because of the β-sialon phase formed during the sintering process and tightly combined with corundum,the structure of the sample is compact and the slag resistance of the material is improved.