Do you know what process is involved in cement production?
Date：2019-06-20 09:07 Source：未知Views:
(1) dry cement production process.
The raw materials are dried and grinded at the same time, or the raw materials are first dried and grinded into raw materials and then fed to the dry kiln to calcinate the mature materials.
However, there is also a method of adding raw powder to water to make raw pellets and feeding them into libo kiln to calcinate mature materials, which is called semi-dry method and still belongs to one of the dry production methods.
(2) wet production process.
A method of calcining mature materials in a wet kiln after grinding the raw materials into raw slurry with gouache.
There is also a method to make raw material block into calcinated mature material after dewatering the raw material pulp prepared by wet method, which is called semi-wet method and still belongs to one of the wet production methods.
The main advantages of dry production are low heat consumption (for example, the heat consumption of dry kiln clinker with preheater is 3140 ~ 3768 coke/kg). The disadvantages are not easy to uniform raw material composition, large dust in the workshop and high power consumption.
Wet production has the advantages of simple operation, easy control of raw material composition, good product quality, convenient slurry transportation, and less dust in the workshop, but the disadvantage is high heat consumption (clinker heat consumption is usually 5234 ~ 6490 coke/kg).
A set of cement production process to produce cement, generally can be divided into three processes: raw material preparation, clinker calcination and cement grinding.
(1) raw material grinding in cement production process
There are dry and wet methods.
The dry method generally adopts closed-circuit operating system, that is, raw material after grinding fine cement, into the separator separation, coarse powder back into cement grinding grinding operation, and most of the materials in the mill at the same time drying and grinding technology, cement equipment used tube grinding, middle unloading grinding and roller grinding.
Wet method usually use pipe mill, baseball mill and other once through the cement mill will not return to the open circuit system, but also use a classifier or arc screen closed circuit system.
(2) calcining in cement production process
The cement equipment for calcining clinker mainly consists of vertical kilns and rotary kilns.
(1) vertical kiln:
A vertical kiln is one in which the shaft is not rotated.
Divided into ordinary vertical kilns and mechanized vertical kilns.
Common vertical kiln is manual feeding and unloading or mechanical feeding, manual unloading;
Mechanical vertical kilns are mechanical loading and unloading.
Mechanical kiln is continuous operation, its production, quality and labor productivity are higher than ordinary kiln.
In recent years, most foreign vertical kilns have been replaced by rotary kilns, but in China's cement industry, vertical kilns still play an important role.
According to the requirement of building materials technology policy, small cement plant applies mechanization vertical kiln, gradually replace the ordinary vertical kiln.
(2) rotary kiln:
Kiln shell is horizontal (slightly inclined, about 3%), and can do rotary motion is called rotary kiln.
Dry kiln for mixing raw powder and wet kiln for mixing slurry (usually with a water content of about 35%).
Cement production process -- grinding:
The fineness grinding of cement clinker is usually carried out by circle flow grinding process (i.e. closed circuit operating system).
In order to prevent the dust flying in the production, cement plant are equipped with dust collection equipment.
Electric dust collector, bag type dust collector and cyclone dust collector are commonly used in cement factories.
In recent years, due to the use of new technologies and new equipment in the aspects of raw material pre-homogenization, homogenization of raw material powder transportation and dust collection, especially the emergence of outside kiln decomposition technology, a new dry cement production process comes into being.
Using this cement production process makes the dry production of clinker quality is no less than wet production, and the electricity consumption is also reduced, which has become the trend of cement industry development in various countries.