The refractory products use the selection principle of the bonding agent, especially the non-fired refractory products and the unshaped refractoriess, and their mechanical strength (structural strength) is mainly provided by the bonding agent. However, there are many kinds of binders for refractory materials, and the bonding mechanism is also different. Therefore, in actual production and use, suitable binders should be selected according to refractory materials, molding or construction methods, and use conditions. The selection principles are as follows:

The nature of the binder must be compatible with the properties of the refractory material being bonded. Acidic, neutral and weakly alkaline binders are available for acidic and neutral refractories. For alkaline refractories, acidic binders cannot be used directly. Neutral or alkaline binders can only be used. If used under reducing conditions, organic binders with high residual carbon can also be used.

The binder to be used should be compatible with the molding method or workability (construction performance) of the material. Sintered refractory products generally use temporary bonding agents (such as lignosulfonates, etc.), non-sintered refractory products generally use chemical bonding agents (such as aluminum dihydrogen phosphate, water glass, etc.); casting refractory materials should be used at room temperature a binder that produces coagulation and hardening, such as hydration-bound, or chemically bonded (hardener), or agglomerated (additional) binder, and the binder and plastic may be adhesively bonded or chemically bonded. Or a ceramic bonded bond; and the spray refractory may use a binder similar to the cast refractory.

The binder selected must be compatible with the high temperature performance of the material and should not reduce or reduce the high temperature structural strength, corrosion resistance (corrosion) and slag penetration resistance of the material. For high alumina or fireclay castables, ordinary calcium aluminate cement or combined clay can be used as a binder, while corundum or corundum spinel castables should be combined with pure calcium aluminate cement or reactive alumina. Agent.