Introduction of raw mill and cement mill using in cement production process. NFLG ball mills and vertical mills are the best choice for your cement plant.
Summary of production process
Cement is typically made from limestone and clay or shale. These raw materials are extracted from the quarry crushed to a very fine powder and then blended in the correct proportions.
This blended raw material is called the ‘raw feed’ or ‘kiln feed’ and is heated in a rotary kiln where it reaches a temperature of about 1400 C to 1500 C. In its simplest form, the rotary kiln is a tube up to 200 metres long and perhaps 6 metres in diameter, with a long flame at one end. The raw feed enters the kiln at the cool end and gradually passes down to the hot end, then falls out of the kiln and cools down.
The material formed in the kiln is described as ‘clinker’ and is typically composed of rounded nodules between 1mm and 25mm across.
After cooling, the clinker may be stored temporarily in a clinker store, or it may pass directly to the cement mill.
The cement mill grinds the clinker to a fine powder. A small amount of gypsum – a form of calcium sulfate – is normally ground up with the clinker. The gypsum controls the setting properties of the cement when water is added.
Cement Grinding Details
1. Raw mill for cement production process
Why raw material grinding?
To make the different ingredients into products of a certain granularity, in order to get required size for clinker calcinations.
Smaller size particular has larger surface area to be completely contacted with each other, bringing fast chemical reaction, which is good to make clinkers of high quality.
When the degree of grinded raw material is too high, it has no obvious positive impact for calcinations, but costs too much electricity. So you have to control the grinded particular finesse in a reasonable range.
The best suitable finesse and granularity: 1.0-1.5% of grinded particular under 0.2mm, 8-12% under 0.08mm
NFLG raw mill development—from ball mill to vertical mill
The ball mill is given priority to high-performance vertical mill, roller machine and so on. Many kinds of mills can be mixed to acquire high yield self-overtaking.
New vertical mill and new technology applications make grinding process more various and more perfect. Grinding and drying integration is realized. You can even use kiln waste gas as drying heat source
Operating control process has got has high level automation with material analysis, inspection automatic control, ingredients measurement, and operating system control.
2. Cement mill
Cement grinding is last process of cement production, also the most power consumption process. Its main function lies in grinding cement clinker (and gelling agent, performance adjusting grinding materials) into suitable particle (by fineness and specific surface area, etc), to form certain particle gradation, increasing its hydration area, accelerating the hydration speed, satisfying the slurry condensation and hardening requirements.
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.