Cement Plant equipments
In the cement plant, we need not only the crushing machinery , but also the grinding machine. stone crusher : limestone crusher Limestone is the main raw materials for making cement, so we need the limestone crusher to crush limestone to small particle sizes to make cement.
Raw mill: it is used to crush limestone particles and additive materials
coal crusher and coal mill : They are used for crushing and grinding coal into powder in cement plant.
Gypsum crusher and mill: In cement plant, they are used for crushing and grinding gypsum into powder.
cement mill : ball mill : They are used to grind cement clinker into powder to make cement.
The main raw materials used in the cement manufacturing process are limestone, sand, shale, clay, and iron ore . The main material, limestone, is usually mined on site while the other minor materials may be mined either on site or in nearby quarries. Another source of raw materials is industrial by-products. The use of by-product materials to replace natural raw materials is a key element in achieving sustainable development.
Raw Material Preparation
mining of limestone requires the use of drilling and blasting techniques. The blasting techniques use the latest technology to insure vibration, dust, and noise emissions are kept at a minimum. Blasting produces materials in a wide range of sizes from approximately 1.5 meters in diameter to small particles less than a few millimeters in diameter.
Material is loaded at the blasting face into trucks for transportation to the crushing plant . Through a series of crushers and screens, the limestone is reduced to a size less than 100 mm and stored until required. Depending on size, the minor materials (sand, shale, clay, and iron ore) may or may not be crushed before being stored in separate areas until required.
In the wet process, each raw material is proportioned to meet a desired chemical composition and fed to a rotating ball mill with water. The raw materials are ground to a size where the majority of the materials are less than 75 microns. Materials exiting the mill are called “slurry” and have flow ability characteristics. This slurry is pumped to blending tanks and homogenized to insure the chemical composition of the slurry is correct. Following the homogenization process, the slurry is stored in tanks until required.
In the dry process, each raw material is proportioned to meet a desired chemical composition and fed to either a rotating ball mill or vertical roller mill. The raw materials are dried with waste process gases and ground to a size where the majority of the materials are less than 75 microns. The dry materials exiting either type of mill are called “kiln feed”. The kiln feed is pneumatically blended to insure the chemical composition of the kiln feed is well homogenized and then stored in silos until required.
Whether the process is wet or dry, the same chemical reactions take place. Basic chemical reactions are: evaporating all moisture, calcining the limestone to produce free calcium oxide, and reacting the calcium oxide with the minor materials (sand, shale, clay, and iron). This results in a final black, nodular product known as “clinker” which has the desired hydraulic properties.
In the wet process, the slurry is fed to a rotary kiln, which can be from 3.0 m to 5.0 m in diameter and from 120.0 m to 165.0 m in length. The rotary kiln is made of steel and lined with special refractory materials to protect it from the high process temperatures. Process temperatures can reach as high as 1450oC during the clinker making process.
In the dry process, kiln feed is fed to a preheater tower, which can be as high as 150.0 meters. Material from the preheater tower is discharged to a rotary kiln with can have the same diameter as a wet process kiln but the length is much shorter at approximately 45.0 m. The preheater tower and rotary kiln are made of steel and lined with special refractory materials to protect it from the high process temperatures.
Regardless of the process, the rotary kiln is fired with an intense flame, produced by burning coal, coke, oil, gas or waste fuels. Preheater towers can be equipped with firing as well.
The rotary kiln discharges the red-hot clinker under the intense flame into a clinker cooler. The clinker cooler recovers heat from the clinker and returns the heat to the pyroprocessing system thus reducing fuel consumption and improving energy efficiency. Clinker leaving the clinker cooler is at a temperature conducive to being handled on standard conveying equipment .
Finish Grinding and Distribution
The black, nodular clinker is stored on site in silos or clinker domes until needed for cement production. Clinker, gypsum, and other process additions are ground together in ball mills to form the final cement products. Fineness of the final products, amount of gypsum added, and the amount of process additions added are all varied to develop a desired performance in each of the final cement products.
Each cement product is stored in an individual bulk silo until needed by the customer. Bulk cement can be distributed in bulk by truck, rail, or water depending on the customers needs. Cement can also be packaged with or without color addition and distributed by truck or rail.
Single-stage hammer crusher
Single-stage hammer crusher is used for limestone crushing. This type of crusher is suitable in crushing medium strength ore such as limestone, marlite, slag, gypsum and coal. It can crush big ore to required size. Moreover, it can crush ore which has moisture and earth in it because it adopts discharging grates in the same direction. It has special iron feeding protection device, which can rebound the uncrushed metals to the feeder , so the operator can stop it if he hears peculiar sound to deal with this matter.