Product Name: White Cement Plant
Capacity: 300 – 5000 T/D
Equipment: Hammer crusher, jaw crusher, preheating tower, rotary kiln, cooler, conveying equipment, ball mill, other auxiliary equipment.
AGICO White Cement Plant Features:
Our company has rich experience in white cement plant design and white cement equipment manufacturing. Our design of the white cement production line is the result of our years of technical improvement and experience accumulation. AGICO white cement plant is able to produce cement clinker with high whiteness and strength, reduce the energy consumption of the production line, and ensure the quality of the white cement produced at the same time.
White Cement Manufacturing Process
The manufacturing process of white cement is similar to that of Portland cement. Compared with Portland cement, white cement has higher requirements for the calcining system in the cement plant. In the production process of white cement, the calcining system is the key part of the whole process, whose quality directly affects the product quality and energy consumption of the whole production line. Therefore, to produce white cement, it is necessary to design the calcining system reasonably.
Fuels for Calcining
In white cement production, natural gas and heavy oil are the most commonly used fuels in the calcining process. Because they do not contain many colored impurities themselves, using them as fuels could effectively reduce the content of colored impurities in the white cement clinker and improve the whiteness of white cement.
A small amount of fluorite will be added to the raw material of white cement as mineralizers to reduce the calcining temperature. In the process of production, the fluctuation of the mixing amount may become liquid phase ahead of time in the preheater and the high-temperature section of cement kiln, which will cause the material to stick and even lead to blocking. This kind of phenomenon may occur at any time in a place where there is cold air leakage.
This is a problem we must pay attention to while designing a white cement plant. We adopt the following techniques in our preheater system to solve this problem:
1. Welding all the flange connection parts of preheater air pipes to completely eliminate air leakage;
2. Using high-quality heat resistant steel as the material of blanking air locking flap valves to reduce the deformation of the valve under high temperature and ensure the air locking effect;
3. Using large-angle air ducts instead of horizontal or circular arc type air ducts to connect the air duct inlet at all levels to avoid material accumulation as much as possible.
Calciner of Kiln
In the white cement production line, the volume of the calciner of kiln needs to meet the requirements that the gas residence time in the calciner is no less than 5.5 seconds. The reason is that the clinker out of the kiln needs to be sprayed with water and fog for sudden cooling, which leads to temperature of the tertiary air in the calciner decrease, and thus the combustion time of the fuel in the calciner is prolonged. This is a key pinot to guarantee the high Carbonate decomposition rate of the raw materials in the kiln and reduce the pressure in the kiln while calcining.
In our white cement plant, we use the combination of spray fog quenching and grate cooler strong wind quenching to bleach the clinker out of the kiln. The principle of this method is to reduce the trivalent iron in clinker to bivalent iron, so as to improve the whiteness of clinker.
In the actual production of white cement, the water consumption of spray fog is determined according to the specific whiteness and strength control requirements of clinker quality. Our design ensures the rational configuration and automatic control of the spray water and the cooling air volume of the grate cooler.
Tertiary Air Duct
Because of the spray, water bleaching will reduce the temperature of the tertiary air in the calciner of the kiln. In order to minimize its adverse effects, we add a layer of 40mm-60mm calcium silicate board in the lining of the tertiary air duct to strengthen its heat preservation and insulation effect.
The recommended cement mills in white cement production are vertical roller mills or ball mills. The use of these two mills is conducive to reducing the iron pollution in the white cement production process.
How Do We Improve Whiteness of White Cement
The color of Portland cement is mainly influenced by its ratio of iron oxide. General Portland cement contains a relatively high level (3%-4%) of iron oxide, which makes it obviously gray; when the content of iron oxide drops to 0.45% – 0.7%, the color of Portland cement will turn to light green; while in white Portland cement, the content of iron oxide is only 0.35% – 0.4%, in addition, there are very few coloring substances such as manganese oxide, titanium oxide, chromium oxide, cobalt oxide, etc., so its color is very close to pure white.
Our white cement plant uses the following ways to improve the whiteness of white cement:
1. During cement clinker calcination, using weak reducing atmosphere and natural gas or liquid fuel without ash powder as fuel to improve the whiteness of white cement clinker.
2. Add a certain amount of gypsum with high whiteness in the cement grinding process to improve the whiteness and fineness of white cement.
3. The mill lining is made of granite, white ceramic, or high-quality wear-resistant special steel, and the grinding body is made of wear-resistant materials such as silicon pebble or artificial ceramic ball to prevent sundries from mixing during the manufacturing process.
About White Cement
White cement (or white Portland cement) is a kind of hydraulic cementitious material, which is made of white Portland cement clinker with less iron oxide content, an appropriate amount of gypsum and mixed materials (limestone and kiln ash).
White cement is more difficult to manufacture and has higher prices than normal Portland cement. White Portland cement clinker is made of pure raw materials, such as pure kaolin, pure quartz sand, pure lime or chalk, at a higher temperature (1500 ℃ ~ 1600 ℃). It is generally used for interior and exterior decoration of buildings. For example, the decoration of stairs, floors, walls, etc. It is not economical to use white cement for structural purposes.