Light burnt magnesia powder is an important refractory material

Light burnt magnesia powder is an important refractory material

Light-burned magnesia powder is a kind of raw material with medium alkalinity and chemical activity, which is used in other industrial fields besides refractory material and cementitious material. In addition, the development of converter slag splash protection technology has further expanded the application scope of light-burned magnesia powder. At present, the slag splashing protection technology mostly uses light-burned magnesia powder into balls, including light-burned magnesia powder balls, carbon-containing light-burned magnesia powder balls, and carbon-containing calcium-containing light-burned magnesia powder balls. Lightly burnt powder

Light-burned magnesia powder, referred to as light-burned magnesia powder, is a kind of active magnesia obtained by calcining magnesite, brucite and magnesium hydroxide extracted from seawater or brine at about 800~1000℃. Light burnt magnesium powder is light yellow and light brown powder, the particle size is mostly below 100 mesh, the periclase crystal is very small, the density is 3.07~3.22g/cm3, the lattice constant is large, the lattice defects are many, and the texture is crunchy. Porous structure, great reactivity, easy to carry out solid-phase reaction or sintering, react with water to form Mg(OH)2 and harden, and has bonding ability.

The choice of calcination method and the control of light calcination temperature are important means to obtain good activity. With the increase of calcination temperature, the specific surface area of MgO decreased significantly. When the temperature is higher than 1000 °C, the recrystallization speed of MgO is accelerated, the dispersion degree drops sharply, and the activity becomes poor. The use of different calcination methods and calcination equipment at the same temperature is also an important factor affecting the activity of MgO. If calcined in a boiling furnace or a suspension furnace, it can be rapidly decomposed in an instant, and light-burned magnesia powder with high activity can be obtained. Tunnel kiln and reflector kiln are used for large blocks, and the calcination time is long, which will often cause the surface to be over-burned and the interior to be burned, which will reduce the activity of light-burned magnesia powder. The use of rotary kiln to calcine granular magnesite, the situation is between the two, can also obtain light-burned magnesia powder with good activity.

1 The weight of each batch of finished products is not more than 120 t.

2 Samples for particle size determination should be sampled before batching, and samples for chemical analysis should be sampled after batching. Small bags (25kg) take one incremental sample per 20 bags, and one incremental sample per large bag (1000kg).

After fully mixing the obtained particle size sample, point 10-20g to measure the particle size. The mixed test samples were reduced to 200g and sent to the laboratory for analysis.

3 If a certain chemical composition is unqualified or abnormal in the inspection result, double the number of samples from the same batch of products shall be taken for re-inspection, and the re-inspection result shall be the final inspection result of the batch of products.