Tangshan Tangbao Refractories Co., Ltd.
Address：Beijiadian Third Street, Guye District, Tangshan
Dry material is an amorphous refractory which is directly constructed by dry powder (vibration, tamping). In the 1970s, foreign countries began to develop dry materials, which have been successfully applied in some fields.
Application in induction furnace. It is used for cast iron, cast steel, melting and refining non-ferrous metals. Silica and fused quartz-silica are commonly used in cast iron. Fused quartz can improve thermal shock resistance and restrain cracking. Boric acid can be used as sintering agent, zircon can be added to the batching to improve high temperature corrosion resistance; cast steel is made of many materials, such as Al 2O 3, fused quartz, Al 2O 3-MgO, Al 2O 3-MgO-MA, A-MA, MgO, MgO, MgO-Al 2O 3, MgO-MA, MgO-Cr 2O 3 and MgO. O-Cr_2O_3-Al_2O_3, MA-MgO-Al_2O_3, and non-ferrous metals, such as Al_2O_3, Al_2O_3-mullite, can be supplemented with fused quartz and silicon carbide. SiC volume expansion during oxidation can restrain sintering shrinkage, avoid cracking and improve service life.
MgO-CaO-Fe_2O_3 dry-type material can be prepared with magnesia-calcium iron sand at the bottom of DC electric furnace and ferroalloy electric furnace. In recent years, in order to reduce the power consumption and lime consumption of electric furnaces abroad, the slag produced is low alkalinity slag, so the magnesia-alumina ramming material prepared with non-aqueous binder is used instead of magnesia-calcium ramming material.
Dry material made of clay clinker and alumina material mixture can be used as pressing repairing material for blast furnace, etc. Dry material made of silica and zircon can be used as sealing material for tundish cover, etc. Dry material can also be used as hot repairing material, repairing converter, ladle and so on. Magnesium dry-type material prepared with magnesia aggregate has been successfully used as tundish lining in China, replacing tundish coating.
Another application area of dry material is the blast furnace tapping ditch. In this respect, information has been reported abroad since the 1980s. The material is Al 2O 3-SiC-C. Binders can be used in many ways. Referring to foreign materials and using sodium silicate as binder, we have successfully developed Al 2O 3-SiC-C dry material for iron trench, i.e. baking-free material. After vibration and filling during construction, it can be put into use immediately after construction. The service life of the tapping trench of the small blast furnace is about 15 days. There is room for improvement in this material. The service life of Al2O3-SiC-C dry material for tapping trench abroad can reach 20-25 days. The advantages of the dry baking-free material for the tapping ditch are that the material can be stored for a long time, the construction is simple, convenient and the cost is not high.
Dry material is prepared without water or any liquid binder. There are also so-called "semi-dry materials" abroad, in which a small amount of water or other liquids are added to the ingredients. At present, liquid phenolic resin is widely used in tapping ditch without baking, which has achieved great technical and economic benefits. The liquid phenolic resin used in the tapping ditch of large blast furnace is different from that in China. The tapping ditch of large blast furnace is used continuously without repairing. The iron flux reaches 132,422 tons and the service life is very long.