What are the main components of refractory cement?
SiO powder is often used. Ultra-fine powder refers to less than 1 / zm particles which are made by hydrolysis of ethyl silicate or made from recycled dust in the smelting process of ferro-silicon alloy. Non-cement castable refractory are castable refractory material which contains no cement instead it relies on the coagulation and combination by adding ultra-fine powder or sol (see refractory castable), and it is an amorphous material with high activity. Silica sol is made through Ion-exchange of sodium silicate after Na ions are removed. The easiest method is to prepare by reaction of aluminum metal with hydrochloric acid or alchlor. It is a thermodynamically unstable system which has certain requirements for ultra-fine powder and sol. It is different from non-cement refractory castable, Cr2zrOz and etc. It has low impurity content, and can bond with itself, so it has good binding strength. Ultrafine powder used in non-cement castables are SiO2, Al2O3, Cr2zrOz, etc. Such recycled SiO2 powder has an average particle diameter of 0.5 pm, therefore when adding the gelling agent (electrolyte), it can coagulate and give the products some bonding strength. Non-cement castable refractory is made up of refractory aggregate and powder and it is round. Since the use of superfine powder or sol as binder. The size of sol particles are of 0.1 ~ 1 m. Non-cement refractory castable takes oxide or synthetic compound ultra-fine powder or oxide sol-gel which is similar to the chemical composition of material in tungsten castable. There are several ways to prepare alumina sol. The sol used are mainly alumina oxide and silica sol. The surface area is large, and it helps to improve high-temperature structural strength. Non-cement castable refractories rely on oxide ultra-fine powder or sol to coagulate and combinate. It is a refractory castable (also known as chemical bonding castable) which uses chemical binder instead of cement for combination.
Refractory cement, also known as aluminate cement, can also be gray. Aluminate cement is often yellow or brown. Aluminate cement takes bauxite and limestone as raw materials, alumina content of about 50% as the clinker. And it is a hydraulic cementing material made by grinding. The main mineral of aluminate cement is mono calcium aluminate (CaO · Al2O3, abbreviated CA) and other aluminates, and a small amount of dicalcium silicate (2CaO · SiO2), etc.
