The main component of Limestone is calcium carbonate , and lime is composed mostly of calcium oxide. The basic principle to produce lime is with high temperature, to decompose the calcium carbonate into calcium oxide and carbon dioxide.
Lime production process:
1. limestone crusher
Limestone broken is an important link in calcined lime production line, cement production line. Limestone crusher often generally selects hammer crusher, but the traditional hammer crusher has some shortcomings, our department of technology do a renovation, such as extend screen frame, mounting combat balance hammer, which greatly improves the service life of the crusher and crushing yield.
2.limestone rotary kiln
After crushing, qualified limestone is deposited in the storage bin, transported into the silos on top of preheater by the hoister. Preheater top bin has upper and lower material level meter controling feeding amount, and then material through the feeding tube to be uniformly distributed to each room of the limestone preheater.Limestone in the preheater is heated to 1150 degrees Celsius, kiln flue gas is heated to 900 degrees Celsius, approximately 30% of decomposition, and by the hydraulic push rod is pushed into the rotary kiln, limestone in a rotary kiln sintering, decomposited into calcium oxide and carbon dioxide. After decomposition, the genetated limestone into the cooler, by the cold air cooling to 100 degrees Celsius, then discharged. The heat exchanged hot air of 600 degrees Celsius into the kiln and mixing combustion with gas. Waste gas in the cold through the induced fan enter into the bag type dust remover, then by the exhaust fan into the chimney. Thel ime ,out of cooler, by vibrating feeder, bucket chain conveyor, bucket elevator, belt conveyor is deliveried into the lime product storeroom. According to customer requirements decide whether it needs screening process.
In the production of metallurgical lime, the main types of kiln are rotary kiln, vertical kiln, etc. In the world limestone rotary kiln is widely used, which has the following advantages:
first, the quality of lime by roasting kiln type is the best of all;
second, it can burn more than 5mm gravel materials, be helpful for mine resource utilization;
third, a high degree of mechanization, simple control system, production and easy operation;
Fourth, the highest capacity of single kiln .
Different kiln type has different preheating, calcining, cooling and discharging method. But a few technology principles are the same : the raw materials of high quality, good quality of lime; high calorific value of fuel, the quantity consumed less; and calcining time proportional to the particle size of limestone; quicklime activity inversely proportional to calcination time and calcination temperature.