Process parameters

(1) Clinker production: ≥ 2500 t/d ； (2) Heat consumption during clinker burning
(3) Comprehensive electricity consumption of clinker
(4) Comprehensive electricity consumption of cement
(5) 28 day strength of clinker
(6) Dust emission concentration

Production method

Cement production mainly uses limestone and clay as raw materials, which are crushed, proportioned, and ground into raw materials through a vertical mill. The raw materials are then fed into a cement rotary kiln to calcine the mature materials. The clinker is then mixed with an appropriate amount of gypsum and some mixed materials or additives, ground into cement through cement grinding, and transported out of the factory by a packaging machine or bulk machine. The cement production equipment adopts the dry cement production process, which involves drying and grinding the raw materials into raw material powder, feeding them into a dry rotary kiln for calcination into clinker. The main advantage of dry production is low heat consumption.

Process description

1. The limestone crushing dump truck pours the limestone into the hopper, and after being crushed by a hammer crusher, it is transported by a belt conveyor to the limestone pre homogenization yard. The cantilever stacker is used for layered stacking and material retrieval. The extracted limestone is transported by a belt conveyor to the limestone batching bin at the raw material batching station. An electromagnetic iron remover is installed on the incoming belt conveyor to remove potential iron components from limestone. A metal detector is installed at the head of the belt conveyor to detect any remaining iron parts in the raw materials, in order to prevent damage to the raw material grinding roller press. The raw material batching station is equipped with batching warehouses for limestone, clay, and other materials. Plate feeders and quantitative feeders are installed at the bottom of each ingredient bin. The four types of raw materials are discharged by their respective quantitative feeders according to the required proportion of ingredients, and the mixed materials are fed into the raw material vertical mill through a belt conveyor 2. The raw material grinding adopts a vertical roller grinding system, which uses the high-temperature exhaust gas discharged from the kiln tail as the drying heat source. After the material is ground by a vertical mill, it is dried and classified by a V-shaped powder selector. The fine powder is selected by an efficient powder selector, and a portion of the fine powder is sent to the raw material homogenization warehouse through an air conveying chute and a bucket elevator 3. The coal mill is located at the kiln tail, and a portion of the kiln tail exhaust gas is collected by a cyclone dust collector and used as a drying heat source for raw coal. After the kiln tail exhaust gas is humidified and cooled by the humidification tower, it directly enters the kiln tail electric dust collector. The amount of water sprayed by the humidification tower is automatically controlled according to the outlet exhaust gas temperature of the humidification tower, so that the exhaust gas temperature is within the allowable range of the kiln tail electric dust collector. The purified exhaust gas from the dust collector is discharged into the atmosphere by the exhaust fan. The kiln ash collected by the humidification tower is transported by conveying equipment to the kiln feeding system or raw material homogenization silo. Set up a continuous raw material homogenization silo, where the raw materials in the silo are aerated in alternating zones and discharged from the surrounding annular zone to the mixing chamber. The raw materials are aerated and stirred evenly in the mixing chamber. The required bottom inflation is supplied by the configured Roots blower. After homogenization, the raw material powder is metered and then fed into the two feed ports of the dual series preheater through an air conveying chute and a bucket elevator, and then through a distribution valve and a lock valve 4. The firing workshop consists of a five stage dual series suspension preheater, decomposition furnace, rotary kiln, grate cooler, and corresponding dust removal system, with a daily output of 2500 tons of cement clinker. The raw materials fed into the preheater are preheated by the preheater and decomposed in the decomposition furnace before being fed into the kiln for calcination; The high-temperature clinker discharged from the kiln is cooled in the grate cooler. The large clinker is crushed by the crusher and then combined with the small clinker leaked to the air chamber, and sent to the clinker storage by the clinker chain bucket conveyor. The hot air from the clinker bed not only provides high-temperature secondary and tertiary air to the kiln and decomposition furnace respectively, but also purifies the exhaust gas through an electrostatic precipitator and discharges it into the atmosphere through an exhaust fan. After the clinker is unloaded by the bottom unloading device of the warehouse, it is transported to the bulk truck station by a belt conveyor. The bulk clinker is directly loaded onto the truck through dust-free bulk heads located at the bottom of each warehouse 5. The coal powder preparation adopts a grinding system, which uses the high-temperature exhaust gas discharged from the kiln tail as the drying heat source. The raw coal is fed into the coal mill by a quantitative feeder under the raw coal bin for drying and grinding. The ground coal powder enters the bag filter with the airflow, and the qualified coal powder is collected and sent to the coal powder bin with a load sensor by a screw conveyor. After being measured, the coal powder is sent to the burner at the kiln head and the decomposition furnace at the kiln tail for combustion. The dusty gas is purified by an anti-static bag dust collector and discharged into the atmosphere through an exhaust fan. Both the coal powder silo and bag filter are equipped with CO detector devices and explosion-proof valves. A central laboratory is established throughout the factory, responsible for the inspection of raw materials, semi-finished products, and finished products; And set up an air compressor station to supply compressed air for the entire factory's production 6. The cement ingredients are prepared using a grinding head bin, and the grinding machine is a φ 3.2 × 13 meter cement mill. The roller press machine is matched according to the situation to achieve a cement output of 180 t/h The finished cement is pneumatically transported to the original cement warehouse by a double bin pump There are four circular warehouses with a diameter of 12 × 42m for cement storage, with a total storage capacity of 20000 tons and a storage period of 4.6 days. The cement finished products from the cement grinding system are transported by pneumatic conveying to the cement storage system. The cement warehouse is equipped with a discharge pressure reducing conical chamber and an inflation device, and the required air source for inflation is provided by a Roots blower. The cement packaging workshop is equipped with two eight nozzle rotary packaging machines, with a single output of 90-100t/h.

Technical Parameter