Fire-resistant clayclinker castable Refractory Materials Iron and steel smelting
Fire-resistant clayclinker is an industrial name. The main minerals are clay minerals and aluminum hydroxide, such as diaspore boehmite, trihydrate, pearlite, kaolinite, dikaite, aluminite, edgestone, illite pyrophyllite Montmorillonite (table 4.4.1) refractory clay, such as in common of clay minerals are quartz, feldspar, mica, followed by iron and manganese oxide hydroxide sulfate sulfide, carbonate, as well as other oxide and silicate minerals In general, more focused on clay minerals is less than 2 microns fraction, the clay mineral is concentrated in the graded part of greater than 2 microns.
The chemical composition of refractory clay is one of the important factors affecting its quality. AlO is a beneficial component of refractory clays. It occurs mainly in aluminum hydroxide minerals (diaspore, boehmite, bauxite), followed by aluminosilicate minerals (kaolinite, illite, montmorillonite, etc.). In general, soft and semi-soft clays contain 30% ~ 45% AlO, hard clays 35% ~ 50%, and high alumina clays 55% ~ 70%.
SiO2 mainly occurs in clay minerals, and there is also trace of primary quartz residue. SiO2 content varies greatly, from 3% to 35% in high alumina clay and 43% to 66% in hard clay.
Fe2O3 mainly occurs in hematite, magnetite, goetite, siderite, is the main harmful component of refractory clay.
The content of Fe2O3 in high alumina clay is 0.5% ~ 2.2%, hard clay is 0.5% ~ 2.5%, soft clay is generally 1.0% ~ 2.5%.
K2O and Na2O are also harmful impurities of refractory clay, which mainly occur in illite and mica, and their contents vary greatly.
CaO and MgO are harmful impurities, but the content is generally very small.
The impurity content in the product shall not exceed 3% for special grade and 4% for other grade; The products shall not be mixed with limestone, loess and other high calcium, high iron and other foreign inclusions. For high bauxite clinker used as refractory material, the technical standard (YB2212-82) is shown in Table 4.4.5. In addition to the physical and chemical indexes listed in the table, it is also required that no more than 10% of the products calcined in contact with coal shall pass through the 10 mm standard sieve, and no more than 10% of the products calcined in rotary kiln and external combustion kiln shall pass through the 5 mm standard sieve. The impurity content in the product shall not exceed 4%; In the same grade, adjacent mixed grade products are not more than 10%; The products shall not be mixed with limestone, loess and other high calcium, high iron and other foreign debris.