Several stages of the development of unshaped refractory castables

The refractory castable can be made into a seamless furnace lining body, and has strong integrity, good air tightness, less heat dissipation loss, and can save energy in the furnace.

The production of refractory castables also has great advantages. It does not require brick presses and firing equipment. The energy consumption is only 1/20 of the refractory shaped bricks, and the production efficiency is 3-8 times that of the refractory bricks. And it is easy to transport, and the construction efficiency is 5-15 times that of refractory bricks.

The production history of refractory castables has gone through several stages:

The first stage is a relatively long process in the 1960s. The main bonding methods are high alumina cement, water glass, phosphate, etc. The main raw materials are made of aggregates and powders mixed with binders.

The second stage was in the 1970s. Aluminum sulfate, polyaluminum chloride, sodium polyphosphate, aluminate cement and clay binder were developed, and castables, gunning materials, refractory plastics and clay-bonded castables were also developed. developed successively. This expands the range of unshaped refractory castables. The successful development of refractory plastics is an important symbol of the upgrading of refractory castables. Overcome the defects of furnace peeling.

The third stage is after the 1980s, using composite binders, ultrafine powders and high-efficiency admixtures. During this period, a series of low-cement refractory castables were successfully formulated, which are characterized by self-bonding, self-sintering, and low calcium content, increasing service life and strength. The application of low-cement and micro-powder technology at this stage is an important sign that the castable enters the high-temperature furnace lining.

At present, the production of silica sol and aluminum sol binders on the market has reduced the iron content and the existence of calcium-free materials, which is also the future development direction. At present, the materials of sol combination method are only produced by a few castable manufacturers in China, and have not been widely popularized.

The above stages prove that refractory castables are more favored by the market because they meet the requirements of environmental protection, and are easy to construct, have strong integrity, and increase their service life.