Effective method for recrystallization of raw materials to achieve high yield

Effective method for recrystallization of raw materials to achieve high yield

If the filtrate of the recrystallization raw material is cooled to room temperature, a9g can be precipitated (regardless of the operation loss), while B remains in the mother liquor. The loss of a is very small, that is, the recovery rate of the purified product reaches 94%. If the solubility of a in this boiling solvent is 47.5g/100ml, the mixture can be fully dissolved when boiling as long as 20ml solvent is used. At this time, a9.4g can be precipitated from the filtrate, and B can still remain in the mother liquor, and the recovery rate of the purified product is as high as 99%. If the solubility of impurities in cold is large and the solubility of products in cold is small, or the solubility of solvents to products changes greatly with temperature, these two aspects are conducive to improve the recovery. And accordingly improve the physical and chemical properties of raw materials. Generally, the calcination temperature of carbonaceous raw materials is 1250 ~ 1350 ℃.

The calcination temperature of needle coke shall reach about 1450 ℃, and the temperature of anthracite calcined in electric furnace shall reach 1500-2000 ℃. When calcining carbon raw materials, the oxidation loss should be reduced as much as possible. The quality of raw material calcination has a significant impact on the quality of finished graphite electrode or other carbon products. The calcination of foreign petroleum coke is generally carried out in raw material manufacturers, and most of the calcination of carbon raw materials used in carbon products in China is carried out in carbon plants. The storage yard of modern large-scale raw material yard (the yard for storing raw materials) includes ore yard, coal yard, auxiliary raw material yard and mixing yard; It not only stores foreign iron ore, iron concentrate, pellet, manganese ore, limestone, dolomite, serpentine, silica, coking coal and power coal, but also stores part of sinter, pellet and circulating materials in the iron and steel plant, such as iron oxide scale, blast furnace ash, crushed coke, sintering powder, homogenizing end materials, etc. Processing raw materials and mixing sintering materials before smelting is one of the important reforms of blast furnace ironmaking technology in industrial developed countries in recent 30 years. It is an effective method for blast furnace ironmaking and iron ore sintering to achieve high yield, high quality, low coke ratio and low fuel ratio.

In the 1960s, some iron and steel enterprises in China had relatively simple raw materials. Most of them used concentrate with stable composition and short transportation distance. Only covered concentrate warehouses were set up in iron and steel plants without special raw material yards.