Low cement refractory castable with different material for different usages
Low-cement refractory castable refers to castable refractories with less than 8% calcium aluminate cement. Requires castable CaO content of less than 2.5%. The main varieties of low-cement (calcium oxide content of 1% ~ 2.5%), ultra-low cement (calcium oxide content of less than 1%) and no cement (calcium oxide content of less than or equal to 0.2%) refractory castables, with high density, low porosity , High strength, low wear, heat shock and corrosion resistance, etc., but also has the characteristics of high volume stability and low construction water consumption.
Low-cement series of castables, according to their material varieties, can be divided into aluminum silicate, mullite, corundum, magnesium aluminum, sharp stone, carbon and silicon carbide and other low-cement refractory castable series. According to its use, it can be divided into furnace cast iron refractory castable and ladle refractory castable and so on.
Common low-cement refractory castable has 3 kinds, here refers to the low cement content. Castable cement content up to 10 ~ 30%, and low cement castable cement content between 3% -8%, then there is a content of 1% called ultra-low cement castable, the last one is without cement casting Material known as cementless castables.
Clay and aluminous low-cement castable for heating furnace, soaking furnace and other heat treatment furnace and rotary kiln lining;
Corundum and chromium-containing corundum low-cement castable used in some parts of the lining of the molten steel refining device lining, but also for the frequency induction furnace lining, petrochemical catalytic cracking reactor high temperature wear-resistant lining;
Low-cement castable used as high-temperature burner lining, heating furnace water pipe wrap; blast furnace trenches, iron furnace taphole, iron pretreatment with the overall spray gun lining and so on.
The use of micronized and ultrafine powders and admixtures is one of the key technologies of low-cement series refractory castables. The mechanism of coagulation and hardening is the result of the combined action of hydration of cement and cohesion of fine powders. It is characterized by high strength, and with the heating temperature increases, the strength increased significantly, the poor permeability of castable, easy to cause peeling or burst during the baking process. Should be based on their species, the thickness of construction and parts, a reasonable system of baking. At the same time, can also add refractory castable refractory agent, such as aluminum metal, aluminum lactate and organic fiber.