• Tel:0086-371-67816766
    Fax: +86-371-68617124
  • Kevin: +86-15038005999
    Angela: +86-15638227908
  • Add : Gongye Road and Tonghang Er Road crossing, Shangjie District, zhengzhou, Henan, China

The process of cement production

Published 2014/10/16 13:29:08

1. Crushing and pre-homogenization
(1) Crushing: Most of raw material such as limestone, clay, iron ore and coal needs to be crushed in the process of cement production. As lime stone is the most consumable raw material in the production of cement with relative granularity after mining and high hardness, the crushing of limestone plays a very important role in the crushing of materials.
(2) Pre-homogenization of raw material: Pre-homogenization technique is to realize preliminary homogenization of raw material to endow raw material storage area with functions of storage and homogenization by applying scientific stacker- reclaimer technology in the storage and removal process of raw material.
2. Preparation of raw material
At least 3 tons of material such as material, fuel, clinker, compound and gypsum shall be grinded for every ton of Portland cement produced. According to statistics, the power consumed by grinding operation in dry cement production line accounts for 60% of power in cement plant, among of which raw material grinding is more than 30%, coal grinding is about 3%%, cement grinding is about 40%. Therefore, reasonable selection of grinding equipment and technological process, optimization of process parameters, proper operation and control of operation system has an important signification to quality assurance and reduction in energy.
3. Homogenization of raw meal
The stability of raw material component is prerequisite to stability of thermal regulation of clinker calcinations in the production process of new dry cement, and raw material homogenization system play an important role in checking the possible problems.
4. Preheating and decomposition
The preheating and partial decomposition of raw material shall be completed by pre-heater to replace partial function of rotary kiln and shorten the length of rotary kiln. At the same time heat transfer process of raw material shall be conducted within rotary kiln in accumulation state and moved to pre-heater to be conducted in state of suspension to ensure intensive mixing of incandescent gas from kiln, which increased contact area of gas material with rapid heat transfer rate and high heat exchanger effectiveness to improve production efficiency of kiln system and reduce kiln system clinker burning into the heat consumption
(1) Deconcentration of material
80% of heat exchange is conducted in the entrance of pipe. The material turns back toward upward and moves with air flow and is dispersed at the same time under the impact of raw material feeding into the pipe in the pre-heater and high speed up flow.
(2) Separation of gas-solid
When air flow carries powder into cyclone, it is forced to rotate and move annular space between cyclone body and internal cylinder, and rotate downward from cyclone body to cone, which can be extended to the end of cone and turned upward for rotating upward. Finally, it is discharged from exhaust pipe.
(3) Pre-decomposition
The emergence of pre-decomposition is a technical leap in cement calcinations process, which ensures that the exothermic process and fuel burning and endothermic process decarbonation of raw material are conducted quickly in suspended state or fluidized state within decomposing furnace and decomposition rate of material is increased to 90% as it is added decomposing furnace between pre-heater and rotary kiln and equipped with fuel injection device by using uptake fuel at kiln back end. Decarbonation conducted in rotary kiln originally is moved to decomposing furnace. Most of fuel is added from decomposing furnace and small part of is added from kiln end, which reduced thermal load of kiln calcining zone, extended the life of lining, and be helpful for large-scale production. Due to homogeneous mixing of fuel and raw material, combustion heat of fuel is transmitted to material to optimize process of combustion, heat transfer and decarbonation.

5. Calcinations of cement clinker

After raw material completes pre-heating and pre-decomposition in the cyclone pre-heater, next procedure is to enter into rotary for calcinations of clinker, and carbonate rotary kiln will be further decomposed quickly and undergoes a series of solid-phase reaction to produce mineral in the cement clinker. The mineral will become liquid phase as the temperature of material is rose, the mineral dissolving in liquid phase will be reacted to produce large amount of clinker. After calcinations of clinker, temperature began to fall. Finally high temperature clinker discharged from rotary kiln will be cooled to the temperature that downstream conveyor, storage and cement mill can bear by cement clinker cooler, recycling sensible heat of high temperature clinker and improving thermal efficiency of system and quality of clinker.
6. Grinding of cement
Cement grinding is not only the last process of cement manufacturing but also most power consumption process. Its principal function is to grind cement clinker, gelatinizing agent and performance controlling material into suitable granularity (fineness and specific area are indicated) so as to form certain grain composition, increase its hydration area, accelerate the hydration speed, and meet condensation and hardening requirements of cement mortar.
7. Cement packaging
There are two shipping methods, namely shipping in bag and bulk when the cement is delivered.

UP:Notes on the Installation of Rotary Dryer
NEXT:The effect of the flow gas within the rotary kiln

Address:Gongye Road and Tonghang Er Road crossing, Shangjie District, Zhengzhou, Henan

Copy Right: Henan Hongke Heavy Machinery Co., Ltd. All rights reserved.