This paper briefly introduces the technical development and innovation situation,and focuses on the practice results and tackling key problems of the calcination of small particle size limestone in beam kiln.

This paper introduces the technical characteristics of Maerz kiln,analyzes the causes of the damage of the high-alumina castable at the top of the connection channel,puts forward the repair construction method,and summarizes the points for attention in the repair construction.

Based on Si powder,SiC grains and powder as the raw materials,Si3N4-bonded SiC standard bricks were prepared by reactive sintering (at maximum 1 420 ℃) through the same processes,which were then post-sintered at 1 750 ℃ for 2.5 hours in flowing N2 atmosphere. The phase compositions,micro-zone compositions,microstructure as well as pore-size distribution of Si3N4-bonded SiC samples before and after post-sintering were analyzed by means of XRD,EDS,SEM and mercury intrusion method respectively.The results showed that after post-sintering at high temperature,the Si3N4-bonded SiC refractories,in which fibrous Si3N4 disappeared and all α-Si3N4 were transformed to relatively large-sized columnar β-Si3N4,presented almost no dimensional change,only a little decrease of bulk density and a little increase of MOR and HMOR （1 400 ℃)；the average pore-size increased dramatically；the steam oxidation resistance at high temperature was also enhanced remarkably.

Majiagou group limestone in preheating and roasting process easily break into powder,seriously affect the normal production of lime,its quality cannot meet the needs of users.By comparative study of the properties of limestone in Majiagou group and Fengfeng group,the results show that the main reasons of limestone breaking in Majiagou formation include unstable aragonite phase,weak oxidation degree and a large number of closed pores and cracks in the structure,resulting in phase transition and volume expansion  of linestone in heating process.At the same time,the factors affecting the limestone breaking are analyzed,and the targeted measures are put forward.

The type of antioxidant is very important to the performance of magnesia carbon bricks.In this paper,fused magnesia,flake graphite and liquid resin are used as the main raw materials and  the effects of the antioxidant types on the bulk density,apparent porosity,cold compressive strength,modulus of rupture at elevated temperatures,permanent changes in dimension and slag resistance are studied.The result shows that firstly both bulk density and cold compressive strength of magnesia carbon brick decrease after adding the antioxidant;secondly the micro expansion of the sample by introducing the antioxidant boron carbide and metal silicon powder is beneficial to the improvement of high-temperature volume stability of magnesia carbon brick;thirdly the sample with antioxidant metal silicon powder has good comprehensive performance.

The Al2O3-SiC-C brick used in iron ladle of a steel mill was analyzed,and the erosion mechanism was studied as well. The results show that the abnormal erosion is mainly caused by MnO in the slag,and the high content of MnO makes the low-melting phase in the brick such as manganese silicate greatly increase and the molten damage generate under the scouring of high-temperature molten iron.

Self-locking structure porous ceramics with continue  mullite framework were prepared by adding NH4F to high purity active mullite powder.The effects of NH4F on micro structure and strength of sample were investigated and characterized by SEM and flexural strength respectively.When 3% NH4F was added, the length-diameter ratio of acicular mullite was 14.11, and the 3D skeleton structure was formed.The mechanical properties of the samples were improved, the strength was up to 99.43 MPa,the porosity was 52.93%.

This paper introduces the damage reason and mechanism of refractory castable during design,construction,drying-out and productive maintenance of water-cooling beam in heating furnace.To avoid damage to the castable,some reasonable technical measures are explored.

Micro-expanded mullite-bonded alumina hollow sphere bricks are prepared at 1 460 ℃ in tunnel kiln, with 0.2~3 mm alumina bubbles and ≤0.044 mm fused white corundum powder as main raw materials and adding different silicon sources into the powders.Mullite forms in the substrate of the brick, and the reaction expansion solves the products shrinkage problem in high-temperature environment for a long time and improves the high-temperature performance of the products.The experimental results show that by adding 15% silicon source C and after being heated at 1 460 ℃ for 35 h, the apparent porosity of the products is 57.7%, the bulk density is 1.49 g/cm3, the refractoriness under load at 0.1 MPa is T0.6>1 700 ℃, and the permanent change in dimension on heating is +0.14% at 1 600 ℃ for 2 h.

In this paper,the preparation technology and characteristics of aluminosilicate  refractory are reviewed.The synthesis routes of aluminosilicate refractory are mainly as follows:firstly,this kind of refractory can be made by firing clay (mixture of kaolin,clay and alumina);secendly,it can be made from mineral of sillimanite group and bauxite;thirdly,it can also be made from sol-gel synthesis,solid waste containing aluminum,slate,aluminum mud,ceramic waste and so on.The properties of the refractory prepared by these processes are described in detail.

This paper introduces the correlation of the thermal items in daily inspection of fused\|cast zirconia corundum brick,discusses and describes every detail in the inspection,and briefly analyzes the influence of different test environments, methods or parameters on the inspection.

In this paper，TGA-16 high-temperature thermogravimetric analyzer is used to study the oxidation-induced weight gain of NOx refractories at high temperatures.By measuring the oxidation-induced weight gain curve and the surface area of the material under the specified heating curves，the initial oxidation temperature，the maximum oxidation rate temperature and the oxidation-induced weight gain per unit area of the material are calculated to characterize the oxidation-resistant performance of the material.