1.1 Refractory Grout
A material with good fluidity after adding water and stirring, also known as pouring material. After molding, it needs to be properly maintained to make it coagulate and harden, and it can be used after baking according to a certain system. The grouting material uses aluminum silicate clinker, corundum material or alkaline refractory clinker as the aggregate; the lightweight grouting material uses expanded perlite, vermiculite, ceramsite and alumina hollow spheres as the aggregate. Calcium aluminate cement, water glass, ethyl silicate, polyaluminum chloride, clay or phosphate are used as binders. The admixture depends on the usage, its role is to improve the construction performance and improve the physical and chemical properties.
The construction and molding methods of grouting include vibration method, pump injection method, pressure injection method, spray method, etc. The overall lining is made of grout, and it is often used in conjunction with metal or ceramic anchors. If it is reinforced with stainless steel fiber, its resistance to mechanical vibration and thermal shock can be improved. The grouting material is used as the lining of various heat treatment furnaces, ore roasting furnaces, catalytic cracking furnaces, reformers, etc., and also used as the lining of melting furnaces and high-temperature melt launders, such as lead-zinc melting furnaces, tin baths, salt baths Furnace, tapping or tapping trough, ladle, suction nozzle of molten steel vacuum circulation degassing device, etc.
1.2 Plastics
Plastic mud or mud. When the appropriate external force is applied, it is easy to deform without cracking; after the stress is removed, it will not deform anymore. Plastic materials include semi-silica, clay, high alumina, zircon, carbon, etc., as well as lightweight plastics. Plastics must be added with plasticizing materials, most of which are high plasticity clays, and plasticizers can also be used to improve the plasticity of this clay. Plasticizers include carboxymethyl cellulose, dextrin, lignosulfonate and the like. The binders used for plastics include plastic clay, phosphoric acid, aluminum dihydrogen phosphate, aluminum sulfate, and the like. Alumina plastics with phosphoric acid or phosphate binders will chemically react with alumina during storage to generate insoluble aluminum orthophosphate and harden the mud, so preservatives such as oxalic acid, citric acid, acetyl Acetone etc.
The construction method generally adopts the ramming method or the vibration method. When building an integral furnace lining with plastic, metal or ceramic anchors must be provided. Plastics can be used as the lining of thermal equipment such as soaking furnaces, heating furnaces, boilers, etc., and also used to wrap the water cooling pipes of heating furnaces.
1.3 Gunning Material
A refractory mixture used for gunning or spraying with a jet machine. According to the gunning method, it can be divided into wet gunning (or mud gunning), semi-dry gunning and fire (flame) gunning. Wet gunning uses compressed air to spray mud containing 20-40% refractory powder, which can achieve high fog dispersion, high adhesion rate, and can carry out relatively uniform thin-layer gunning. The semi-dry gunning is to add water to the nozzle to wet the refractory powder sprayed by compressed air. The amount of water added is 11-14%, and the adhesion rate is low, and thicker layer gunning can be carried out. Fire gunning belongs to dry gunning. The gunning material is sent to the flame of the fuel-oxygen spray gun, and the gunning material is partially melted in the nozzle flame and attached to the brick lining.
The gunning material is made of aluminum-silicon, aluminum-silicon-zirconium, magnesium, magnesium-calcium, magnesium-chromium, etc. The binders used are sodium silicate, phosphate, polyphosphate, asphalt, resin and the like. In order to improve the adhesion rate, additives such as clay, bentonite, and lime are added. In order to ensure that the gunning material can achieve good sintering, a sintering aid is also added, such as serpentine, pure olivine, lime, refractory clay, iron oxide, etc.
1.4 Refractory Coatings
The material applied to the lining of refractory bricks. Depending on the requirements of use and construction methods, refractory coatings are formulated into paste-like and mud-like forms. The binder used varies depending on the material, such as alkaline coatings phosphate, polyphosphate, magnesium sulfate for the preparation of continuous casting tundish; clay, aluminum dihydrogen phosphate, aluminum chromium phosphate, water glass, etc. for the preparation of high-alumina coatings . In order to improve the spreadability of coatings, additives such as plasticizers are generally added. The coating is mainly used as a protective coating for the lining of various thermal equipment, or for repairing local damage to the lining of bricks.
1.5 Ramming Material
A bulk refractory material with very low or no plasticity. The materials are siliceous, clay, high alumina, corundum, zircon, silicon carbide, carbon, magnesia, etc. According to the material of the ramming material and the conditions of use, inorganic binders or organic binders similar to the pouring materials can be used, such as water-soluble dextrin, carboxymethyl cellulose, lignin, sulfonate, polyvinyl alcohol; water-resistant and Thermoplastic paraffin, asphalt, tar, phenolic resin, random polypropylene, etc.
The ramming material is constructed by forced ramming, with low porosity and high density. Therefore, among the unshaped refractories, the ramming material is especially suitable for the lining of melting furnaces and various containers containing high-temperature molten metal. Such as open hearth and electric furnace hearths, various induction furnace linings, blast furnace tapping ditch, ladle and so on.
1.6 Projection Refractory Material
A semi-dry, lined mud that is projected with a projector. Mainly used to build the lining of the overall steel ladle. The materials are siliceous, alabaster, clay, high alumina and zircon. The most used are high-silica and high-alumina projection materials.
