TYPES OF BLOCKS
Carbon blocks are made of mainly carbonaceous material and are difficult to dissolve into carbon-saturated molten iron (carburizing dissolution). Carbon block can be used in blast furnace to create furnace bottom, hearth features of good thermal shock resistance with low thermal coefficient expansion.
Carbon refractory has high thermal conductivity and electrical conductivity, using carbon refractory in the furnace bottom and hearth can make cooler play full performance, thereby extending the life of furnace lining material to prevent burning through. Carbon blocks are made of mainly carbonaceous material and are difficult to dissolve into carbon-saturated molten iron (carburizing dissolution). Carbon blocks have relatively high thermal conductivi- ty compared with those of other refractories of oxidized metal sys- tems, and they efficiently protect the hot face.
Mullite Blocks are made of synthetic fused mullite or sintered mullite, pressed by selected shaping processes, and fired in high temperature furnaces. It is ideal for the production of refractories such as fired or unfired bricks, castables and plastic mixes.
Mullite bricks are high-alumina refractories with mullite (3Al2O3·2SiO2) as the main crystal phase. Generally, the alumina content is between 70% and 80%. Mullite Refractory bricks have high refractoriness, which can reach above 1790℃. The starting temperature of load softening is 1600～1700℃. The chemical composition of mullite in refractories is usually close to 3Al2O3·2SiO2, which corresponds to the Al2O3 content of nearly 72 wt. %. The idealized formula of the most commonly produced mullite is 3Al2O3·2SiO2, however, the ratio of alumina and silica may vary from 2:1 to 3:2.