Raw material workshop: limestone crusher (hammer crusher, jaw crusher, etc.), stacker reclaimer for limestone pre homogenization, raw material mill

Combustion workshop: coal pre homogenization equipment, coal mill, rotor scale, preheater, rotary kiln, cooling machine, etc

Cement workshop: cement mixing, roller press, cement mill, packaging machine, etc

There are also various measuring belts, belt conveyors, fans, etc

technological process

1. Crushing and pre homogenization

(1) In the process of crushing cement production, most of the raw materials need to be crushed, such as limestone, clay, iron ore, and coal. Limestone is a raw material with a large amount of cement production. After mining, the particle size is large and the hardness is high. Therefore, limestone is a raw material with a large amount of cement production. After mining, the particle size is large and the hardness is high. Therefore, the crushing of limestone plays an important role in the material crushing of cement plants.

The crushing process is more economical and convenient than the grinding process, and it is very important to choose crushing and grinding equipment reasonably. Before the material enters the grinding equipment, try to crush the large pieces of material into small and uniform particle sizes as much as possible to reduce the load on the grinding equipment and increase the output of the grinder. After the material is crushed, it can reduce the separation of materials of different particle sizes during transportation and storage, resulting in the production of uniformly composed raw materials and improving the accuracy of batching.

(2) Pre homogenization technology for raw materials refers to the use of scientific stacking and retrieval techniques during the storage and retrieval process of raw materials, to achieve preliminary homogenization of raw materials and enable the raw material storage yard to have both storage and homogenization functions.

The basic principle of pre homogenization of raw materials is to continuously stack the incoming raw materials into as many parallel, overlapping, and equally thick layers as possible in a certain way by the stacker during material stacking. When picking up materials, try to cut all layers at the same time in the direction perpendicular to the material layer, and cut them in sequence until they are all picked up, that is, "flat and straight".

significance:

(1) Homogenize the composition of raw materials, reduce quality fluctuations, facilitate the production of higher quality clinker, and stabilize the production of the firing system.

(2) Expand the utilization of mining resources, improve mining efficiency, maximize the coverage and interlayer of the mine, and minimize or eliminate waste rock during the mining process.

(3) The quality and control requirements for mining can be relaxed to reduce the mining cost.

(4) Strong adaptability to sticky and wet materials.

(5) To provide long-term stable raw materials for the factory, and also to mix different components of raw materials in the yard, making it a pre batching yard, creating conditions for stable production and improving equipment operation rate.

(6) High degree of automation.

2. Raw material preparation

In the process of cement production, for every ton of Portland cement produced, at least 3 tons of materials (including various raw materials, fuels, clinker, mixtures, and gypsum) need to be ground. According to statistics, the power consumption of the dry cement production line grinding operation accounts for more than 60% of the total power consumption of the plant, of which raw material grinding accounts for more than 30%, coal grinding accounts for about 3%, and cement grinding accounts for about 40%. Therefore, reasonable selection of grinding equipment and process flow, optimization of process parameters, correct operation, and control of operating systems are of great significance for ensuring product quality and reducing energy consumption.

working principle:

The electric motor drives the grinding disc to rotate through the deceleration device, and the material falls into the middle of the grinding disc through the air locking feeding device and the discharge chute. Under the action of centrifugal force, it is thrown towards the edge of the grinding disc and crushed by the grinding roller. The crushed material overflows from the edge of the grinding disc and is dried by the high-speed upward hot air flow from the nozzle. According to the different airflow speeds, some of the material is carried into the effective powder selection machine by the airflow, and the coarse powder is separated and returned to the grinding disc for re grinding; Fine powder flows out of the mill with the air and is collected in the dust collection device of the system, which is the product. Coarse particles that are not carried by the hot air flow overflow the grinding disc and are fed into the powder mill by the external circulation bucket elevator. The coarse particles fall back into the grinding disc and are squeezed and ground again.

3. Raw material homogenization

In the production process of new dry process cement, stabilizing the composition of raw materials entering the pit is a prerequisite for stabilizing the thermal system of clinker burning, and the raw material homogenization system plays a role in ensuring the stability of the composition of raw materials entering the pit.

Principle of homogenization:

By using air agitation and gravity, a "funnel effect" is generated, which allows the raw material powder to cut multiple layers of material surfaces as much as possible and mix thoroughly when unloading downwards. By using different fluidized air, the parallel material surfaces in the warehouse undergo varying sizes of fluidized expansion, with some areas unloading and others fluidized, resulting in the tilting of the material surfaces in the warehouse for radial mixing and homogenization.

4. Preheating decomposition

The preheating and partial decomposition of raw materials are completed by the preheater, replacing some of the functions of the rotary kiln, to shorten the length of the kiln. At the same time, the heat exchange process of the stacked feed in the kiln is moved to the suspended state inside the preheater, so that the raw materials can be fully mixed with the hot gas discharged from the kiln, increasing the gas contact area, fast heat transfer speed, and high heat exchange efficiency, achieving the goal of improving the production efficiency of the kiln system and reducing the heat consumption of clinker burning.

working principle:

The main function of Yongxian Machinery for preheaters is to fully utilize the waste heat from the exhaust gas discharged from the rotary kiln and decomposition furnace to heat the raw materials, preheat the raw materials, and partially decompose carbonates. In order to maximize the heat transfer efficiency between gas and solid, achieve high yield and low consumption of the entire calcination system, it has three functions: uniform dispersion of gas and solid, rapid heat transfer, and effective separation.

(1) Material dispersion

80% of the heat exchange occurs within the inlet pipeline. The raw material fed into the preheater pipeline is deflected upward by the high-speed rising airflow and dispersed.

(2) Gas-solid separation

When the airflow carries the powder into the cyclone, it is forced to rotate and flow in the annular space between the cyclone body and the inner cylinder (exhaust pipe), and moves downwards while rotating, from the cylinder to the cone, extending all the way to the end of the cone, and then turning upwards to be discharged through the exhaust pipe.

(3) Pre decomposition

The emergence of pre decomposition technology is a technological leap in cement calcination process. It involves adding a decomposition furnace between the preheater and the rotary kiln, utilizing the kiln tail rising flue, and installing a fuel injection device to enable the exothermic process of fuel combustion and the endothermic process of carbonate decomposition of raw materials to rapidly occur in a suspended or fluidized state inside the decomposition furnace, thereby increasing the decomposition rate of raw materials into the kiln to over 90%. Move the carbonate decomposition task that was originally carried out in the rotary kiln to the decomposition furnace; Most of the fuel is added from the decomposition furnace, with a small amount added from the kiln head, which reduces the heat load on the calcination zone inside the kiln, prolongs the life of the lining material, and is conducive to large-scale production; Due to the uniform mixing of fuel and raw materials, the combustion heat of the fuel is promptly transferred to the material, optimizing the combustion, heat exchange, and carbonate decomposition processes. Therefore, it has a series of excellent performance and characteristics such as effectiveness and low consumption.

4. Burning of cement clinker

After the raw material is preheated and pre decomposed in the cyclone preheater, the next process is to enter the rotary kiln for clinker burning.

In the rotary kiln, carbonate further decomposes rapidly and undergoes a series of solid-phase reactions, producing minerals such as,,, etc. in cement clinker. As the temperature of the material increases, minerals such as,,, etc. will turn into liquid phase, and those dissolved in the liquid phase will react to produce a large amount of clinker. After the clinker is burned, the temperature begins to decrease. The high-temperature clinker discharged from the rotary kiln is cooled by a cement clinker cooler to a temperature that downstream transportation, storage, and cement mills can withstand. At the same time, the sensible heat of the high-temperature clinker is recovered to improve the thermal efficiency and clinker quality of the system.

5. Cement grinding

Cement grinding is a later process in cement manufacturing and also a process that consumes a lot of electricity. Its main function is to grind cement clinker (as well as gelling agents, performance adjusting materials, etc.) to the appropriate particle size (expressed in fineness, specific surface area, etc.), form a certain particle size distribution, increase its hydration area, accelerate the hydration rate, and meet the requirements of cement slurry setting and hardening.

6. Cement packaging

Cement can be shipped in two ways: bagged and bulk.