1. The molecular ratio is high and can be stabilized between 2.8-3.0; the main content is high, the impurity content is low, and the actual yield is high.
2. The use of polymers in the new start-up tank has the advantages of being more stable than cryolite electrolytes, shrinking more slowly, and changing molecular ratios more gently, which is conducive to the stable maintenance of electrolyte components; the cathode absorbs sodium evenly, which is conducive to extended The electrolytic cell has a long service life; the electrolysis temperature is reasonable, has small changes, and is easy to control; and has low volatilization loss, which can effectively improve on-site operating conditions.
3. It can save a lot of sodium fluoride or soda ash and reduce production costs.
4. There are three states: sandy (80 mesh), powdery (200-325 mesh), and granular (0-10mm).
- Powdered cryolite (200-325 mesh) This product is particularly suitable for electrolytic aluminum groove opening. It is also suitable for wear-resistant fillers for resin grinding wheels, metal flux glass opacifiers, enamel opal whitening agents, etc. The adding method is simple and easy to operate.
- Sand-like cryolite (80 mesh) Sand-like cryolite is developed using national patented technology and jointly developed by many fluoride salt experts and electrolytic aluminum experts. This product has been tested by the "National Light Metal Quality Supervision and Inspection Center" and all performance indicators have reached or exceeded the national standard for cryolite. The product has the characteristics of low melting point and fast melting speed. It can shorten the time to enter normal working state. Sand-like cryolite particles are larger and have good fluidity. Most of the particles are concentrated in 240 mesh-80 mesh, which is convenient for mechanization and automatic cutting.
- Granular cryolite (0-10mm) is mainly used as a flux for aluminum electrolysis, especially suitable for start-up and normal production of electrolytic aluminum. The actual yield in electrolytic aluminum production is high, which can reduce the cost of electrolytic aluminum; it has the advantages of good fluidity and no dust pollution, and is suitable for mechanized blanking. This product is a new generation of green and environmentally friendly product developed by Duofuo Company based on the international market's requirements for cryolite.
High molecular weight cryolite is a new product independently developed by Duofuo Company and is listed as a national high-tech product.
Types: According to the ratio of sodium fluoride to aluminum fluoride molecules, cryolite can be divided into high molecular ratio cryolite and low molecular ratio cryolite. At present, most of the electrolytic aluminum plants in China use low molecular weight cryolite with a molecular ratio of 1.8 to 2.2 as the electrolyte for aluminum electrolysis. Since the use of high molecular weight cryolite is superior to low molecular weight cryolite in terms of environmental protection and economic benefits, various electrolytic aluminum plants in China generally use high molecular weight cryolite as the electrolyte for aluminum electrolysis. Cryolite can be divided into sandy cryolite, granular cryolite and powdery cryolite according to its physical properties.
Cryolite
1. The characteristics of sand-like cryolite are: ① Low melting point, fast melting speed, which can shorten the time to enter normal working state; ② The molecular ratio can be larger Adjustable within the range, it can adapt to the different requirements for cryolite molecular ratio in different periods of the electrolytic cell; ③ low moisture content, small fluorine loss; ④ granular, good fluidity, easy to transport; ⑤ raw materials are easy to obtain, low production cost.
2. The characteristics of granular cryolite are:
①Good fluidity, dust pollution, suitable for mechanized cutting; ②High actual yield in electrolytic production, which can reduce the consumption of electrolytic aluminum Cost; ③ The molecular ratio is between 2.5 and 3.0, which is especially suitable for opening the groove of electrolytic aluminum; ④ Most of the particles are 1~10mm.
3. The characteristics of powdered cryolite are:
① It can reach a higher particle size, usually above 200 mesh; ② The molecular ratio can reach 1.75~2.5, which has better Adjustability; ③ Ultra-fine products, with a pass rate of 325 mesh of more than 98, which can meet the requirements of cryolite in special industries.
1. Physical and chemical properties of cryolite
Molecular formula Na3AlF6, molecular weight is 209.94, it is a complex compound or a double salt of NaF and AlF3, and its color is white due to impurities. , off-white, yellow powder or crystalline particles, with a melting point of 1025°C, a bulk density of 0.6~1.0g/L, a true density of 2.95~3.05g/cmamp; sup3;, a generated heat of 225KJ, and a specific gravity of 2.75~3.00g/cmamp ;sup3;, heat of fusion 107KJ.