What types of unshaped refractory materials can be classified according to construction methods----- Henan refractory brick manufacturer
What types of unshaped refractory materials can be classified according to construction methods----- Henan refractory brick manufacturer
Refractory materials can be divided into two types: fixed and unshaped. Fixed materials refer to refractory bricks, while unshaped refractory materials refer to a type of refractory material composed of a certain particle size of refractory aggregate, powder, and binder additives, which can also be referred to as dispersed refractory materials. Unshaped refractory materials can be roughly divided into the following types based on construction methods and material properties:
1、 Castable:
A material with good fluidity after mixing with water. The pouring material is made of aluminum silicate clinker, corundum material, or alkaline refractory clinker as aggregates; Lightweight pouring materials use expanded perlite, vermiculite, ceramic particles, and alumina hollow balls as aggregates. Binders include calcium aluminate cement, water glass, ethyl silicate, polyaluminum chloride, clay, or phosphate. Admixtures depend on their usage and their function is to improve construction performance and enhance physical and chemical properties. After forming, it needs to undergo appropriate curing to solidify and harden, and can be used after baking according to a certain system.
2、 Plastic:
Plasticized clay or adobe. Plastic materials include semi silica, clay, high alumina, zircon, carbon, etc., as well as lightweight plastic materials. Plasticizing materials must be added to plastic materials, which are mostly high plasticity clay. Plasticizers can also be used to improve the plasticity of this clay. Plasticizers include carboxymethyl cellulose, dextrin, lignosulfonate, etc. The binders used for plastic include plastic clay, phosphoric acid, aluminum dihydrogen phosphate, aluminum sulfate, etc. Aluminum oxide with phosphoric acid or phosphate binder can be plastic. During storage, it will react with aluminum oxide to produce insoluble aluminum orthophosphate, which hardens the mud. Therefore, storage agents such as oxalic acid, citric acid, acetylacetone, etc. need to be added. When applying appropriate external forces, it is easy to deform without cracking; After stress relief, there will be no deformation.
3、 Spray repair material:
A refractory mixture used for patching or spraying with a spraying machine. Spray repair materials include aluminum silicon, aluminum silicon zirconium, magnesium, magnesium calcium, magnesium chromium, etc. According to the spray repair method, it can be divided into wet spray repair (also known as mud spray repair), semi dry spray repair, and fire (flame) spray repair. Wet gunning uses compressed air to spray mud containing 20-40% refractory powder, which can achieve high mist dispersion, high adhesion rate, and can be used for a relatively uniform thin layer gunning. Semi dry gunning is the process of wetting refractory powder sprayed by compressed air with water at the nozzle. The amount of water added is 11-14%, and the adhesion rate is low, allowing for thicker gunning layers. Fire gunning belongs to dry gunning, which sends the gunning material to the flame of the fuel oxygen spray gun. The gunning material partially melts in the nozzle flame and adheres to the brick lining.
4、 Refractory coating:
Material applied to refractory brick lining. According to different usage requirements and construction methods, refractory coatings can be prepared in the form of mud paste or mud. The binders used vary depending on the material, such as alkaline coatings phosphate, polyphosphate, and magnesium sulfate used in the preparation of continuous casting tundish; To prepare high alumina coatings, clay