The classification of light weight refractory castable
Jun 27,2017
Light refractory castable is a lightweight material for the aggregate and get the cast material. Among them, lightweight aggregate includes expanded vermiculite, expanded perlite, ceramsite, porous refractory and alumina hollow sphere.
According to the use of temperature, light castable can be divided into the following three categories.
(1) low temperature light refractory castable. Low temperature light castable use temperature below 900 ℃, often use expanded vermiculite, expanded perlite, ceramsite as aggregate, with ordinary Portland cement, bauxite cement or water glass as a binder. For example, the castable material with a particle size of 8 to 10 mm and the bauxite cement prepared by the ratio of perlite: cement (35 to 50): (50 to 65) Bulk density 0.3 ~ 0.7 g / m3, compressive strength of 0.5 ~ 0.9 MPa, thermal conductivity (700 ℃) 0.06 ~ 0.18 W / (m · K).
(2) medium temperature light refractory castable. Medium temperature light castable use temperature of 900 ~ 1200 ℃. Usually with porous clay particles, clay clay, shale ceramsite as aggregate. With bauxite cement, calcium aluminate cement or aluminum dihydrogen phosphate for the combination of Jing.
Fine powder can be added to a small amount of silica powder and floating beads to reduce its bulk density. Cement and other binding agent dosage can be determined according to the strength requirements, the higher the strength requirements, the greater the amount of binding agent.
(3) high temperature light refractory castable. High temperature light castable use temperature higher than 1200 ℃ above. They are corundum, high alumina, mullite, clay and magnesia, magnesium aluminum spinel and other lightweight particles or hollow ball as aggregate, calcium aluminate cement, aluminum dihydrogen phosphate, silica sol , Aluminum sol, silica powder as a binding system. Which can be added to the refractory fiber to improve their strength. The most common for the clay and mullite light castables. The following describes the physical and chemical indicators of lightweight refractory castables.
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