First, the refractory castable binder is a material that binds refractory aggregates and powders and produces refractory castables. The cementing method is divided into hydration, chemical combination, polymerization and condensation and other combinations, or a combination of several ways of combining. Bonding agent is an important component of refractory castables, the type is divided into two kinds of inorganic binder and organic binder, and the most commonly used inorganic binder. Inorganic binder can be divided into cement and other types of binder before a Portland cement, aluminate cement and magnesite cement, mainly through the hydration of cement leaving the refractory castable to produce strength; A kind of water glass, phosphoric acid, phosphate, sulfate, soft clay and ultrafine powder, mainly through its chemical, polymerization and coagulation and other effects, so that refractory castables produce strength; organic binder mainly sulfite pulp waste Liquid, dextrin, starch, carboxymethyl cellulose, ethyl silicate, tar pitch and phenolic resin, etc., mainly through its adhesive bonding, polymerization or condensation of carbonization and other effects to obtain strength, mainly in the following categories.
(1) hydration bonding - by means of the joint agent at room temperature and water hydration reaction to produce hydration products and produce a combination.
(2) chemical combination - by means of binding agent and hardener, or between the binder and refractory material at room temperature chemical reaction, or chemical reaction occurs when heated with a binding agent to produce a combination of compounds.
(3) Polymerization knot - The bonding strength is generated by polycondensing the binder to form a network structure by means of a catalyst or a crosslinking agent.
(4) ceramic combination - refers to the combination of low temperature sintering, that is, in the bulk refractory can be added to reduce the sintering temperature of the additives or metal powder to greatly reduce the liquid phase temperature, promote low temperature solid-liquid reaction and low temperature sintering.
(5) Adhesive binding - is combined by one of the following physical effects: 1) Physical adsorption: Combining the interaction between molecules - van der Waals forces; 2) Diffusion: Under the action of thermal motion, the binder and the molecules of the binder are interdiffing to form a diffusion layer, thus forming a strong combination; 3) electrostatic interaction: the interface between the binder and the adhesive there is a double electric Layer, by the double layer of electrostatic attraction and produce a combination.
(6) Agglomeration bonding - by adding a coagulant to microparticles (colloidal particles) cohesion and produce a combination.
HOME