Process parameters

(1) Clinker production: ≥ 3000 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 and proportioned into raw materials, and then fed into a cement rotary kiln to calcine mature materials. The clinker is then added with an appropriate amount of gypsum, mixed with some mixing materials or additives, ground into cement through cement grinding, and transported out of the factory by packaging machines or bulk machines. The dry cement production process commonly used in cement production equipment. The method of simultaneously drying and grinding raw materials into raw material powder, and feeding them into a dry rotary kiln for calcination into clinker. The main advantage of dry production is low heat consumption.

Technological process

5.1 Limestone crushing
The factory has installed a limestone crushing plant. The limestone after quarrying is poured into a hopper made of concrete by truck, and there are steel plates with bars. It is extracted by a heavy-duty skirt feeder with a processing capacity of 550 tons/hour The crusher is a hammer crusher with a capacity of 550 tons/hour. It can crush limestone blocks with a maximum size of 1000 millimeters to less than 75 millimeters. In order to prevent overload of the crusher, the speed of the crusher feeder is changed by a hydraulic drive unit to respond to the power consumption of the crusher drive motor. Equipped with a scraper conveyor to collect the spilled material from the skirt feeder onto it. Crushed limestone is transported by a belt conveyor to a circular premix bed. Provide a belt scale with an accumulator for measuring crushing capacity. Provide pulse jet cleaning bag filter for dust removal of crushing equipment
5.2 Limestone pre homogenization
The crushed limestone is laterally cantilevered, with a stacking capacity of 600 tons/hour and a cyclic storage capacity of 24000 tons. Provide a bridge type reclaimer with a capacity of 300 tons/hour for extracting limestone onto the subsequent belt conveyor
5.3 Crushing and transportation of auxiliary materials and coal
Additives (clay, iron ore, etc.) and coal will be transported to the factory by dump trucks. The crusher will be fixed in a covered warehouse. The skirt feeder feeds materials with a moisture content below 10 into the crusher. The crushed material will be transported by a belt conveyor to a long premix yard
5.4 Additives and Coal Premixing
The additive is dumped into a concrete dumping hopper by truck, lined with steel plates with bars, and extracted by a heavy-duty skirt feeder The crushed material will be stored on a longitudinal material premix bed. Provide a belt scale with an accumulator for measuring crushing capacity Coal is transported to the premix warehouse through a belt conveyor. These materials are stacked through horizontal suspension rods to form two vertical inventories. Provide two cantilever reclaimers for extracting corrective materials onto subsequent belt conveyors for delivery to the raw material proportioning hopper and coal hopper
5.5 Raw material batching and transportation
The raw material batching station has four silos: limestone silo, mixing silo, clay silo, and iron silo. Below each bin, a weighing feeder automatically and smoothly discharges materials from the bin according to a given ratio. The mixed raw materials are transported to the factory through a belt conveyor
5.6 Raw material grinding and waste gas treatment
The vertical grinder will be used for grinding raw materials. The production capacity of the raw material mill is 210t/h. The raw materials will be proportioned according to the set ratio and then sent to the grinder for drying. The ground material will be carried by air into the cyclone separator, and the coarse particles will be collected by the integrated separator and then sent back to the crusher for further grinding. The dusty air coming out of the cyclone separator will be processed in a bag filter before entering the atmosphere. The raw materials collected by the cyclone separator and bag filter will be sent to the raw material homogenization bin The hot air used for drying raw materials will be extracted from the cyclone preheater
5.7 Raw Material Homogenization Warehouse
The mixing system includes a multi feed system and a continuous mixing bin with a capacity of 7500 tons. The multiple feeding system ensures the formation of uniform layers across the entire cross-section of the silo. The homogenization effect is influenced by the funnel flow during the discharge process activated by circulating aeration in the bottom region. This hybrid system exhibits high homogenization efficiency and low energy consumption. Homogeneous raw materials are fed into the kiln feeding system at the bottom space of the mixing silo Homogenized raw materials are fed through electric flow valves and belt scales, and then sent to the upstream pipeline of the preheater through conveying equipment and bucket elevators. The air in the homogeneous silo should be provided by a Roots blower
5.8 Kiln feeding system
Send the raw materials from the raw material homogenization silo to the weighing bin. After being measured by the impact flow meter below the hopper, the raw material is sent to the preheater system through a belt type bucket elevator. When the kiln temporarily stops, the raw materials are returned to the raw material homogenization silo
5.9 Clinker sintering system
A dry rotary kiln with a diameter of 4.0x60m will be used, which has a single series of 5-stage cyclone dust collectors, a pre decomposition furnace, and a grate cooler. The system capacity is 2500t/d and the heat consumption is 740kcal/kg. Weigh the raw material, then send it to the preheater for preheating and partial decarbonization, and then send it to the pre decomposer for calcination. The decarbonization rate of CaCO3 in the raw material at the kiln inlet is about 95%. Raw materials are further decarbonized and burned in the kiln. The clinker with a temperature exceeding 1350 ℃ will enter the grate cooler for quenching. The clinker temperature at the outlet of the cooler is 65 ℃ plus the ambient temperature The exhaust gas discharged from the preheater has a temperature of about 310 ℃ and will be used for drying raw materials. The exhaust gas from the cooler will be discharged into a bag filter for purification before being discharged
5.10 Storage of clinker
The clinker is discharged from the cooler onto the clinker bucket chain conveyor and transported to a 27000 ton clinker silo. A 500 ton unburned clinker bucket will be installed inside the silo. The clinker will be transported to the clinker batching bin through a belt conveyor
5.11 Grinding and transportation of gypsum and additives
Gypsum is transported from the mine to the site, directly discharged from a dedicated discharge port, and then crushed in a PEX250 × 1000 crusher. When the crusher is closed, the gypsum is retained in a dedicated material pile and then sent to the crusher by the front-end loader. After crushing, the gypsum is then transported to the silo through a belt conveyor
5.12 Cement Grinding
Clinker, gypsum, limestone or other additives are extracted from their respective hoppers in predetermined proportions by a weighing feeder equipped with a speed controller The two units of the φ 3.8 × 13m ball mill are the main equipment of the cement grinding department. The weighing feeder below the material box will feed according to the set ratio. The mixture will be fed into the mill through a belt conveyor. The ground cement material will be sent to the separator through a bucket elevator and an air slide. The finished product will be sent to the cement silo through an air slide valve, while the coarse particles will be returned to the ball mill. The exhaust gas discharged from the mill will be purified in the bag filter and discharged into the atmosphere
5.13 Cement Storage
Four cement silos with a diameter of 15m and a storage capacity of 20000t. The cement from the cement plant is transported to the top of the silo by elevator. The cement in the silo is transported to the intermediate silo through a skateboard, and the cement discharged from the intermediate silo is transported by a cement bulk truck (3 × 150 t/h) or by an air chute to the cement packaging machine
5.14 Cement Packaging
Two sets of cement packaging machines (8-port rotary packaging machines, 100t/h) will be used for cement packaging The dust caused by packaging is collected by a bag filter and sent to a bucket elevator through a screw conveyor, and then discharged into the packaging machine through the screw conveyor, while the exhaust gas is discharged through a fan
5.15 Coal Grinding
The coal grinding system will use ball mills. When the moisture content of the raw coal is ≤ 10%, the moisture content of the product is ≤ 1%, the particle size of the raw coal is ≤ 25mm, and the fineness of the product is 80m and the sieve residue is ≤ 10%, the overall system output is 18t/h
5.16 Central Control Room and Central Laboratory
In the central control room, routine process operations and controls will be performed, while in the central laboratory, quality control and testing will be carried out on raw materials, fuels, finished products, and semi-finished products
5.17 Air Compression Station
An air compressor station will be installed, with 5 screw booster air compressors installed at a displacement of 23m3/min and a pressure of 0.8Mpa, to provide dry, oil-free, and waterless compressed air to consumers in the production line.

Technical Parameter