The suitable temperature of light weight acid resistance refractory castable
Lightweight, acid-resistant castable is a granular and powdery material made by adding a certain amount of binder to a refractory material. It has high fluidity and is suitable for amorphous refractory materials that are cast by casting.
Lightweight castable acid resistant to 800 ~ 1200 ℃ acidic medium (nitric acid, hydrochloric acid, sulfuric acid, acetic acid, etc.) corrosive pouring refractories. It is based on water glass as a binder, with acidic or acid-based refractory as aggregate and powder, plus a small amount of coagulant configured.
As the main varieties of amorphous materials, light-weight castables have the common features that they can be directly used without firing. In many kinds of unshaped materials, the production process is relatively simple and does not require special equipment. The mechanized construction is the most Simple, high material utilization, in addition generally has a high room temperature strength, can be made prefabricated in the rotary kiln site installation, such as the chimney lined casting. Acid-resistant castable is mainly used in metallurgical furnaces, but also in the petroleum, chemical, building materials, electric and mechanical industrial kilns and thermal equipment widely used.
Lightweight acid-resistant castable is not resistant to alkali, hot phosphoric acid, hydrofluoric acid and high-fat corrosion. Casting material configured with such sources of raw materials rich, low prices, so in metallurgy, for the configuration of refractory castable aggregate mainly silica, cast stone, wax stone, andesite, diabase and other several raw materials used Acid resistance (gravimetric method,%): 98% of castings, more than 97% of silica, 92% ~ 97% of clay clinker, 92 ~ 96% wax stone, andesite greater than 94%. Choose what kind of raw materials according to the conditions of use. However, when using silica, it is necessary to pay attention to the polycrystalline transformation of quartz during heating and the volume change (expansion) during the transformation. Therefore, it is better to use waste silica bricks to replace part of the silica raw material for aggregate, and to configure this castable powder The main use of silica fume powder, porcelain powder, high silica clay clinker powder, which cast stone is the use of more acid, the general modulus 2.6-3.2, a density of 1.38-142, g / g. The results of water glass should be higher water glass M, in order to reduce the amount of sodium silicate water into Na2O, improve the acid resistance, cubic centimeter of water glass solution. There are many compounds that can be used as water glass promoters, including fluorochemicals (such as fluorosilicic acid, fluoboric acid, alkali metal salts of fluorotitanic acid), esters, acids (such as ethyl acetate), metal oxides Such as lead, Azusa, barium and other oxides), as well as carbon dioxide (CO2), but the most widely used is sodium silicate (Na2SiF6), easy to use, easy to control the condensation hardening time. Acid refractory castable is mainly used for anti-corrosion flue and chimney lining, acid storage tank, pickling tank lining, nitric acid purge tower lined, acid recovery furnace lining and other acid.