A.Raw materials

1.Limestone

The particle size of limestone is required to be 10 to 40 mm, and the portion exceeding the upper limit of 40 mm and the lower limit of 10 mm shall not exceed 5%.

2.Fuel

The fuel can be gas, natural gas, coalbed methane and coal powder.

B、Product quality indicators

The quality index of active lime products meets the first grade products specified in the industry standard YB/T042-2004(See table below).

C.Process flow

1.Raw material storage and transportation

Limestone with a particle size of 10 to 50 mm is transported to the plant site, stacked in the stockyard, and the loader is operated by the stockyard. The material with qualified particle size is loaded into the receiving trough set by the loading yard by the loader, and the feeding material is quantitatively fed by the feeding trough, and the stone material is fed to the large dip angle conveyor, and then sent to the screening building, and the limestone is screened. After being weighed, the qualified particle size is weighed and sent to the top silo of the preheater by the large angle conveyor. The powder under the sieve is sent to the yard by the 3# conveyor and is regularly transported by the forklift.

2.Limestone calcination

Limestone calcination is composed of vertical preheater + rotary kiln + vertical cooler, the output is 100~800t/d, and the material is introduced into the preheater body from the top silo of the preheater through the discharge chute, and the rotary kiln is also The incoming high-temperature flue gas preheats the material to above 1000 °C, so that the limestone is partially decomposed, and then pushed into the tail of the rotary kiln by hydraulic push rods. After being calcined at a high temperature in the rotary kiln, it is discharged into the cooler and blown through the fan. Cooling by cold air, the material is cooled to ambient temperature +60 ° C below the cooler. The air blown through the cooler enters the rotary kiln as secondary air to participate in combustion.

3.Finished product delivery

The finished lime is discharged from the cooler and transported to the finished lime storage via a chain conveyor, bucket elevator and belt conveyor. The lime silo discharge valve is used to transport the lime in the silo into the car and the tanker. Set different sizes of silos according to customer reserve requirements.

The finished product silo adopts a circular silo, 2 5~50mm finished product warehouses, 1 <5mm finished product warehouse, and the amount of each silo is about 800t;

4.Flue gas treatment

The high-temperature flue gas generated by the combustion of the rotary kiln is cooled to below 250 °C after heat exchange with the limestone in the preheater, and then into the cyclone dust collector for primary dust collection, and the large particles of dust are collected, and then It enters the bag type dust collector and is discharged into the atmosphere by a high-temperature fan after dust removal. The dustconcentration of the exhaust gas is less than 30mg/m3. A cold air control system is installed at the inlet of the dust collector to protect the dust collector.

The output of the rotary kiln is stable and suitable for large, medium and small active lime production lines.

1.The rotary kiln is open-type calcination. 

2.The rotary kiln can directly calcine 10~50mm fine-grained limestone. 

3.The vertical preheater at the kiln tail can make full use of the high temperature flue gas generated by calcination in the rotary kiln, and preheat the limestone from the normal temperature to the initial decomposition state. 

4.The vertical cooler at the kiln head can not only quench the high temperature lime, improve the activity of the product, but also facilitate transportation and storage. 

5.The flue gas discharged through the vertical preheater of the kiln is low in temperature and low in dust content, so that the configuration of the subsequent flue gas treatment is simple and efficient, and meets environmental protection requirements.

6.The stable quality of the rotary kiln lime is a relatively large advantage.