1. Broken and pre-homogenization
(1) Broken --- In
cement production process, most of the raw materials demand to be broken, such as limestone, clay, iron ore and coal. Limestone is the largest amount raw materials for
cement production process. After mining, its particle size is larger and its hardness is stronger,so crushing limestone plays a important role in the materials' crushing of cement plant.
(2) Raw materials' pre-homogenization --- pre-equalization technology is the stacker-reclaimer technology by using technology in the
cement production process of depositing and withdrawing raw materials to achieve raw materials' initial homogenization,which can make materials stockyard have two functions: storage and homogenization.
2. Raw material preparation
In
cement production process, producing tons of portland cement should grind at least three tons of material (including a variety of raw materials, fuel, clinker, mixed materials, gypsum). According to statistics,theconsumption of power for grinding operations of the dry cement production line is above 60% of the whole plant and raw materials grinding occupy above 30%, coal grinding occupy 3% and cement grinding occupy 40%. Therefore, it is a great significance for ensuring product quality and redusing energy consumption by the means of reasonable choice for grinding equipment and process, optimization of process parameters,correct operation and controling operation system.
3. Raw meal homogenizing
In dry
cement production process, stabilizing raw materials into the kiln is the premise for stabling clinker burning thermal system, Raw meal homogenizing system plays the final control role for stabling raw material into the
rotary kiln.
4. Pre-heat and decomposition
Preheaters complete the raw materials' preheating and partial decomposition,instead of some features of
rotary kiln,which can shorten the length of kilns,transfer heart between gas materials in the accumulation state in the kiln,proceeding in the Suspended state by moving to preheater,which can make raw materials mixing with hot gas(which is exhausted by kiln), increasing the contact area of gas,transfering heat quickly,increasing heat exchange efficiency to achieve greater production efficiency of the kiln system and reduce the clinker heat consumption.
5. Sintering of cement clinker
Raw materials complete pre-heating and
precalciner in the cyclone preheater.The next process is that entering into
rotary kiln to the sintering of clinker.In the
rotary kiln, carbonate decompose rapidly and take place a series of solid-phase reaction to produce the mineral in the cement clinker.With materials' temperature rising,mineral could become liqiud, dissolved in the liquid phase and neutralization reaction take place to produce a lot of clinker.
6. Cement grinding
Cement grinding is not only the last process in the cement manufacturing process but also the most power consumption process.Its main function is to grind cement clinker(gelling agent, performance tuning materials) to appropriate particle size(fineness, superficial area),form a certain particle size distribution,increase the hydration area and accelerate the hydration rate to meet the requirements of cement slurry condensation and sclerosis.
7. Cement packing
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