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Comprehensive analysis of limestone processing technology2020-10-14 15:00:56

Limestone raw materials can be roughly divided into:
1. Sand and gravel, when used as building aggregate: generally processed to 1-4cm.
2. Production of active lime and pure lime, used in cement industry, metallurgical desulfurization and dephosphorization agent.
3. Chemical powders are used in papermaking, rubber, plastics, coatings, coatings, and inks. The product price depends on the product size, whiteness, and surface treatment. The price difference is about ten times.
4. Limestone cast machine-made sand is 28-75 mesh. This kind of sand has better collapsibility than quartz sand, and the surface of the casting is smoother. Desulfurization gypsum production line, the general processing particle size is 0-2mm.
5. Feed calcium supplements that directly or indirectly supplement calcium to the human body.
There are three main processing techniques:
⑴. Sand and gravel; when used as construction aggregate: generally processed to 1-2cm. Production of sand; feeder-sand making machine-conveyor belt-sand washing machine for sand and gravel aggregates. Making casting sand: The particle size of the casting sand produced by limestone is 28-75 mesh. This kind of sand has better performance than quartz sand, has good collapsibility, is easy to clean up, improve the surface quality of castings, and increase the surface finish of castings.
⑵. Quick lime production: (limestone -> calcination (rotary kiln) -> calcium oxide (calcined generally in block)) rotary kiln production process of lime: ⑴ limestone → vibrating feeder → belt conveyor, from The raw material silo is upgraded to the screening equipment, the limestone of appropriate size enters the preheater, and the kiln tail is preheated at a high temperature of 1000°C, and 20%-25% of the limestone is decomposed → pushed into the rotary kiln. ⑵Further calcined in the rotary kiln, completely decomposed at 1300℃.
⑶ When entering the cooler, its temperature is 1100℃, and the lime is cooled to 70-100℃ by the blower at the bottom of the cooler. Then there is a vibrating feeder in the lower part of the cooler and is discharged to the conveyor, and then sent to the finished product warehouse through conveying, screening and lifting equipment, which is the final active lime product.
⑶. Grinding powder as chemical filler.
Papermaking: more than 200 mesh
Rubber, plastic: above 400 mesh
Coating, coating: 600 mesh or more
Ink: above 1500 mesh
The finished products of milling powder mainly include: light calcium, heavy calcium, calcium hydroxide, ash calcium, double fly powder.

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