Refractory mud is composed of refractory powder, binder, and additives. Almost all refractory raw materials can be made into powder for preparing refractory mud. Ordinary refractory mud is made by adding refractory clinker powder and an appropriate amount of plastic clay as a binder and plasticizer. Its room temperature strength is relatively low, and ceramic bonding is formed at high temperatures to have higher strength. Chemical bonded refractory mud, which uses hydraulic, pneumatic, or thermally hard bonding materials as the bonding agent, undergoes a certain chemical reaction and hardens before the temperature below which ceramic bonding is formed.

The particle size of refractory mud varies according to usage requirements, with an ultimate particle size generally less than 1mm, and some smaller than 0.5mm or finer.

The selection of refractory slurry materials should consider consistency with the refractory products of masonry. In addition to being used as a joint material, fire-resistant mud can also be used as a protective coating for the lining by applying or spraying.

Characteristics and applications of refractory mud: 1. Good plasticity and convenient construction; 2. High bonding strength and strong corrosion resistance; 3. High fire resistance, up to 1650 ℃± 50 ℃; 4. Good slag penetration resistance; 5. Good thermal peeling performance. Refractory mud is mainly used in coke ovens, glass kilns, blast furnace hot blast furnaces, and other industrial kilns. The industries applied include metallurgy, building materials, machinery, petrochemicals, glass, boilers, electricity, steel, cement, etc.

Refractory mud can be divided into dry soil refractory mud, high alumina refractory mud, silicon refractory mud, magnesium refractory mud, etc. according to the different composition materials. According to the different binders, refractory mud can be further divided into the following three categories:

(1) Ceramic bonded refractory clay is a mixture composed of refractory fine aggregate and ceramic binder (plastic clay). The delivery status is dry and needs to be added with water before use. It is hardened by ceramic bonding at high temperatures.

(2) Hydraulic bonded refractory mud is a mixture composed of refractory fine aggregate and hydraulic binder (cement) that plays a major binding role. The delivery status is only dry and can be used after adding water, without heating during hardening.

(3) Chemical bonded refractory mud is a mixture of refractory fine aggregates and chemical binders (inorganic, organic-inorganic, organic). The delivery state can be either slurry or dry, hardening below the ceramic bonding temperature. According to the hardening temperature, this refractory mud can be divided into two types: gas hardening and thermal hardening. Gas hard refractory mud is commonly prepared with gas hard binders such as water glass. Thermosetting refractory mud is commonly prepared with heat-setting binders such as phosphoric acid or phosphate. After hardening, this heat-resistant refractory mud not only has high strength at various temperatures, but also has characteristics such as small shrinkage, tight joints, and strong corrosion resistance.

Refractory clay can be divided into two types: finished and semi-finished products. The so-called finished refractory mud refers to the raw material and clinker that have been prepared in proportion by the manufacturer, and only need to be mixed evenly with water according to the standard during on-site use; Semi finished or non finished refractory mud is a mixture of raw materials and clinker that is not mixed together. When used on site, it should be thoroughly mixed according to the composition of different mud and mixed evenly with water according to regulations.