is a carbonate mineral, mainly composed of calcium carbonate and magnesium carbonate, including iron dolomite and manganese dolomite, respectively. Dolomite is a relatively common mineral. Dolomite can be used in building materials, ceramics, glass and refractory materials, chemical industry, agriculture, environmental protection, energy saving and other fields. It is mainly used as a flux for alkaline refractory materials and blast furnace ironmaking; production of calcium-magnesium phosphate fertilizers and preparation of magnesium sulfate; and ingredients for the production of glass and ceramics.
The comprehensive utilization value of dolomite is very high, so how to process dolomite? What machines are used in the processing of dolomite powder?
Production process of dolomite powder
The processing flow of dolomite powder is divided into 4 parts, namely crushing, grinding, collecting and packaging.
1. Crushing part
First, the large pieces of dolomite mined are initially crushed by jaw crushers or hammer crushers
. If necessary, it can be sent to the cone crusher
for further medium and fine crushing. The reason why the two-stage crushing is selected is to realize the full dissociation of the useful materials of the raw ore and provide better ore raw materials for the grinding stage.
2. Grinding part
The crushed dolomite fragments will be transported from bottom to top by bucket elevator to the silo, and then sent to the dolomite milling machines
for deep grinding processing evenly and quantitatively by the electromagnetic vibrating feeder.
Eventually it becomes dolomite powder that can be used in various fields.
3. Dolomite powder collection part
The dolomite powder processed by the dolomite milling machines
will be classified by the classifier
, and the unqualified fine powder will be sent back to the host
for re-grinding, and the dolomite powder that meets the fineness requirements will enter the finished product silo through the pipeline device.
4. Dolomite powder packaging part
Finally, the packaging machine
is used for packaging.
Dolomite Milling Machines
According to the different dolomite powder size, CLIRIK recommends the following 3 dolomite milling machines:
1. 30-325 mesh (613-33 micron) dolomite powder - YGM Raymond Mill
2. 150-3000 mesh (74-5 micron) dolomite powder; D97=5 micron-HGM micro powder grinding mill:
3. 600-3000 mesh (20-5 micron) dolomite powder; D50=2 micron D97=4 micron-CLUM vertical roller mill:
Application range of dolomite
Dolomite is one of the important raw materials for alkaline refractories, mainly used for steel-making converter lining, open hearth furnace, electric furnace wall, and secondly used for thermal equipment such as external refining devices and cement kilns. Dolomite can be used to make dolomite bricks; when dolomite bricks are used as furnace lining, the method of spraying dolomite gunning materials can significantly increase the life of the furnace.
2. Magnesium smelting industry
Dolomite with a raw ore particle size of 30-120mm is an important raw material for the production of metallic magnesium. The method of smelting magnesium from dolomite is mainly divided into two categories, electrolysis and silicothermal reduction. The electrolysis process is complex and difficult to obtain economic benefits, so small magnesium plants should not use this method; the silicothermal reduction method is to calcinate dolomite It is mixed with ferrosilicon and fluorite to make balls, which are heated in a vacuum furnace at 1100°C to reduce magnesium vapor and other substances, and then the magnesium vapor is cooled and recovered and cast into magnesium ingots.
3. Production of magnesium compounds
Dolomite can produce magnesium compounds such as magnesium carbonate, magnesium oxide, magnesium sulfate, and magnesium hydroxide. At present, there are mainly three types of magnesium carbonate produced: light magnesium carbonate, light spherical magnesium carbonate and light transparent magnesium carbonate. Light magnesium carbonate is the basic raw material of inorganic chemical industry. It is mainly used in the manufacture of magnesium salts, magnesium oxide, elemental magnesium, fireproof materials, printing inks, ceramics, household chemicals, fillers and reinforcing agents for rubber products. It can also be used in shipbuilding, Boiler, steelmaking, glass, paint, medicine and other industries. As a filler, magnesium oxide is widely used in industries such as rubber, enamel, wire and cable. Magnesium sulfate crystals (MgSO4·7H2O), also known as diarrhea salt, are used in medicine, agriculture, cement, printing and dyeing, and food.
4. Production of glass
Dolomite and limestone are the third largest components of glass raw materials except silica sand and soda ash. In the production of bottle glass, soda ash is the most expensive component. The addition of limestone can partially replace soda ash, but it will have adverse effects. The introduction of magnesium oxide in dolomite can further reduce costs. Dolomite can also provide calcium oxide in the glass industry, adding soda-ash-silica system to act as a flux. In addition, dolomite can also reduce glass aging, prevent chemical corrosion caused by the atmosphere or moisture, improve the plasticity of colored glass, and increase the strength of glass.
5. Production of ceramics
Dolomite is used in blanks and glazes, and MgO and CaCO3 are introduced to replace talc and calcite. The role of MgO is to change the composition of the mixing system, thereby reducing the firing temperature of the green body; promoting the dissolution of quartz and the formation of mullite, increasing the amount of quartz and reducing the amount of feldspar, thereby increasing the transparency of the green body. Adding dolomite to the glaze is less prone to smoke than the calcite-added glaze, and crystallization rarely occurs.
6. Production of paint
Dolomite can produce new type extender pigments. Its chemical composition is stable, and it has many advantages such as weather resistance, anti-settling property, fine powder, easy dispersion, high whiteness, low cost, and unique craftsmanship. It can be used in various paints. The coating produced has the characteristics of reducing the amount of titanium dioxide, high hardness, good hand feeling, good flu, strong adhesion, etc., and the application effect is better than that of heavy calcium carbonate.
7. Garden decoration materials
Dolomite is not only the main mineral raw material for artificial marble and terrazzo (light) stone, but also some densely structured and fine-textured dolomites are also used as decorative materials and craft materials. Dolomite is processed into new types of decorative materials such as floor tiles, wall tiles and boards. It has many characteristics such as light weight, high strength, anti-aging, and beautiful appearance, and is deeply favored by people. Decorative railings and ornaments made of dolomite as the main material are also very popular.
8. Adjust soil pH
Since long-term use of urea and other fertilizers is likely to cause the soil to be acidic, dolomite can be added directly to the urea to keep the soil at an appropriate pH value, which can generally increase crop yields by 15-40%, and can also improve the efficacy of herbicides. Dolomite can also compensate for the loss of magnesium content in the soil. It can be used as a fertilizer filler to improve the conditions for plants to use soil nutrients, reduce agglomeration, and facilitate the adjustment of the fertilizer ratio.