Our company provides complete sets of equipment for the active lime production line. The production capacity can reach up to 1,200 tons per day. Active lime is widely used in the production of steel, alumina, magnesium metal, calcium carbide and power plant desulfurization paper. Activated lime can assist steelmaking. The use of activated lime can increase the quality and capacity of steel and reduce the loss and cost of steelmaking. Active lime can also be operated stably. Actual production has shown that the use of activated lime in the steelmaking industry is very profitable. In recent years, the steel industry has used lime and steel production capacity has increased by 40%. High-quality lime with an activity higher than 300ml increased from 27% to 29.5%.
600 Tons Of Active Lime Production Line Equipment Explaination
1. Practice has proved that active lime can improve the desulfurization and dephosphorization efficiency by 80% and shorten the smelting time. It takes only 3 to 5 minutes for the active lime to react completely with the acidic material in the molten steel. The lime reaction time in the shaft kiln takes at least 6 to 10 minutes. It can also increase the ridge by more than 40% and reduce the furnace load by 5-8Kg/t steel. According to the calculation of 10,000,000 tons, it can save about 15 million per year. Its production efficiency is remarkable.
2. Active lime can improve the efficiency of desulfurization and dephosphorization. The average sulfur removal rate of activated lime in steel is 34.5%. Especially high S iron (S ≥ 0.06%), the efficiency is more obvious. Desulfurization remover consumption can be reduced by about 45%.
3. Using active lime to make iron, iron material consumption can be reduced by 5-15Kg / t steel than non-active lime, can also reduce steel splash and oxygen gun adhesion; sticky mouth; flue adhesion phenomenon.
4. Lime consumption is reduced: steel is produced using inactive lime, and the consumption is greater than 65~70Kg. The steel is made from activated lime and the consumption is 40~41.5Kg / t steel. Compared with non-active lime steelmaking, the consumption of reactive lime steel can be reduced by 20~25Kg / t steel.
5. Active lime has remarkable desulfurization and dephosphorization ability. It increases production efficiency by 5% to 10%.
6. Quality requirements of activated limestone: CaO ≥ 52% SiO2 ~ 2.0% MgO ≮ 1.5%
Process and equipment of 600 Tons Of Active Lime Production Line
1. Raw material delivery system
Limestone and dolomite are crushed in the mine and transported to the factory. Screen from material pits and transport to raw material storage. The qualified limestone particles are 10~50mm in size. The qualified limestone is conveyed to the top silo of the preheater by the lifting device. The feed size of limestone is 10~50mm. More than 90% of the finished product has a limestone size of 5 to 40 mm.
2. Active lime calcination system
The active lime calcination system consists of a vertical preheater, a rotary kiln and a cooler.
Vertical preheater: It consists of a preheater body, a storage bin, a feed pipe, and a hydraulic push rod device. The preheater uses compartment dividers in polygonal and circular shapes. The limestone is first heated slowly to avoid violent heating and rush into the kiln to produce a large amount of powder. The decomposition rate of limestone is 30% to 40%. The average temperature of the exhaust gas is 230 ° C ~ 260 ° C, reducing heat consumption.
The rotary kiln consists of a cylinder, a support device, a transmission, a wheel stop device, a kiln tail, a kiln head seal, and a kiln head cover. The kiln body inclination is 3.5%. The kiln body is equipped with two sets of support devices. Roller bearings are water-cooled, oil-lubricated bearings. It can be automatically aligned with the spherical tile. A hydraulic blocking wheel is also arranged near the ring gear. The kiln body is driven by a variable frequency motor to drive the kiln. Spring-loaded seals are installed at the kiln head and at the kiln end. The variable frequency motor driven kiln has a preheater decomposition rate, which can effectively control the calcination temperature and time to meet the combustion and combustion requirements.
The coal burner uses a four-channel burner of coal and gas. It is flexible and convenient to operate and flexible to operate. The jet speed can be adjusted during operation. It is possible to call out a flame suitable for different furnace conditions. It is easy to control the calcination temperature.
The vertical cooler consists of a cooler body, a fixed screen, a cooling device, an electric vibration discharge machine, and the like. The vertical cooler has multiple cooling discharge zones. The discharge speed of each zone can be controlled separately. The cooling effect is good. The ash temperature is low. The ash temperature is 40 ° C above ambient temperature. After cooling the lime, the air is cooled and the temperature can be preheated to above 600 °C. Half is used for the second combustion air of the rotary kiln, and the rest is used to dry the pulverized coal. The cooler has no moving parts, simple structure and good quality.
3. Pulverized coal preparation system
The pulverized coal preparation system is an important part of the active lime rotary kiln system. It consists of two systems, one is a pneumatic sweeping coal mill tubular crushing mechanism powder system with a bag filter. It is easy to operate and clean. The production process is as follows: the lime is fed into the belt from the bucket elevator and then conveyed to the coal bunker through the belt. The hot air is introduced from the rotary kiln system or the flue gas discharged from the auxiliary combustion chamber to dry. The pulverized coal is discharged from the coal mill and then separated into the separator. The coarse pulverized coal is then returned to the mill through an automatic ash discharge valve. The fine powder is driven by the airflow into the baghouse to separate the powder and the gas. The gas is discharged from the separator and purified by an exhaust fan to discharge the dust. A part of the exhaust gas is recovered in the coal mill, and another part of the exhaust gas is discharged into the atmosphere through the chimney. The pulverized coal collected by the dust collector is discharged into the kiln coal storage tank. According to the needs of the coal bunker, the combustor is used to burn the air blower for burning limestone.
4. Finished product delivery system
The finished lime is conveyed to the bucket elevator by a chain bucket machine, and then enters the top screen granary through the elevator. Qualified finished lime is conveyed to the finished product bin by a belt conveyor. The finished lime with a powder of 5 mm or less is delivered to the powder bin. The finished product delivery system includes an electric discharge valve, a finished product warehouse and a powder bin. The finished product warehouse is used to buffer measurements. The finished product is sent to a carbon steel plant for use with reduced powder.
5. Flue gas treatment system
After the high-temperature flue gas burned in the rotary kiln exchanges heat with the limestone in the preheater, the temperature drops below 260 °C. The high-temperature flue gas is first cooled by a multi-tube cooler and then into a high-temperature bag filter. After that, the high-temperature flue gas enters the atmosphere through the chimney, and the dust concentration is less than 30 mg / Nm3.
The system meets the modern process requirements of the active lime precalciner kiln production line and ensures reliable operation of the process equipment. Its process parameters are stable and can guarantee product quality. It has the advantage of saving energy and increasing the operating rate of the production line. The whole process uses advanced technology to control PLC control and DCS control. It can not only improve product quality, reduce consumption, but also improve the reliability and maintenance of electronic control equipment, and realize the modernization of control, monitoring and operation.
6. Product quality
CaO ≥ 93, MgO ≤ 4.5, SiO2 ≤ 1, P ≤ 0.01, S ≤ 0.025 ignition loss ≤ 3, active degree ≥ 350ml ~ 380ml ≤ 1.5%, burning, burning ≤ 1.5%.
Qualified limestone is transported to the top of the silo by a hoist. The top silo consists of a 2-stage controlled feed. The limestone is then evenly distributed in each room of the preheater. The limestone is heated from 1150 ° C to 900 ° C by kiln flue gas in a preheater and decomposed by about 30%. The limestone sintered in the rotary kiln is decomposed into calcium oxide and carbon dioxide. The cold air was blown into a cooler and cooled to 100 ° C for discharge. The kiln and gas mixed combustion is carried out by hot air heat exchange at 600 °C. The gas mixes with the cold air and enters the dust collector through the fan and enters the chimney through the exhaust fan. Lime is transported from the cooler to the lime product warehouse by vibrating feeders, chain bucket conveyors, bucket elevators and belt conveyors.
Vertical preheaters are one of the main active lime equipment. The main function of the vertical preheater is to transport the limestone material to the preheater and to use the high temperature exhaust gas to calcine the effluent from the kiln. During the preheating process, 30% of CaCO3 decomposes under the preheater and is then calcined by a hydraulic push rod into the rotary kiln. In the calcination process, not only the limestone calcination time is greatly shortened, but also the lime activity is higher.
The vertical preheater system is mainly composed of six parts.
1. The feeding system mainly includes an upper chamber and a discharge tube. The feeding system is a material and structure that ensures the safety of the feed of the preheater seal, so that the outside of the cold air cannot enter the interior of the preheater. A glue valve can be used for feeding.
2. Preheater: Its purpose is to ensure that the material is preheated to 900 degrees Celsius. The preheater consists of a preheating chamber, suspension, refractory lining and other parts. Most of this structure is a metal part material. It is necessary to choose high temperature heat resistant steel working at 1000~1100 degrees Celsius. The refractory lining structure has novel design and good sealing performance, which can ensure the preheating of the materials in the preheater and reach the preheating temperature.
3. Push device: It mainly includes the push rod, frame and connecting rod parts. It is cast or welded from propelled heat resistant steel. It is resistant to high temperatures. Hydraulic pushers automatically control the program with electric and hydraulic systems.
4. Hydraulic system: It is mainly composed of fuel tank, pump, motor, solenoid valve and hydraulic oil pipe. Its main function is to control the pushing device to complete the pushing action.
5. Charging chamber: It mainly includes a chute feeding chamber, a charging port and a valve body. Its main function is to put the material into the rotary kiln for preheating and calcination.
6. Frame: It consists of a column and a ring beam. Its main function is to carry the superstructure of the preheater.