Calcium carbonate powder is made with natural calcite, marble or chalk as raw material. After ground and classified by mechanical equipment, calcium carbonate can reach a certain fineness. At present, there are many types of processing equipment for calcium carbonate in our country, such as: impact mill, jet mill, roller mill, vibration mill and ball mill. Combine these equipment with classifier can form an ultra-fine powder processing system, this processing system can produce ultra-fine carbonate powder.
In the processing of dry ultra-fine powder, water, as grinding aid, plays an important role . As a professional powder machinery manufacturer, Qingdao Epic Powder Machinery Co., Ltd. will introduce to you the effect of water ratio on processing calcium carbonate by mill.
Generally, the effect of water ratio on processing calcium carbonate by mill mainly includes the follwoing three aspects:
➊ Thermal effect
The grinding mill generates a lot of heat during processing. An appropriate amount of water can take away some of the heat and lower the temperature inside the mill, thereby reducing equipment failures and improving production efficiency.
➋ Particle shape
Too much or too little moisture content will result in agglomeration of particles or unevenness of particle size, which will affect product quality and application effect. Appropriate amount of moisture can make particles disperse evenly and obtain a better particle size distribution.
➌ Equipment maintenance
Excessive moisture may block filter bag of dust collector, then increase maintenance cost and cause pollution to the environment. Only when moisture content of raw materials is within an appropriate range can the system achieve optimal operating condition.
As we know, the collision and friction of the particles will generate excess charges in the mill. These charges accumulate on the surface of particles, the particles would have a certain amount of power. When particles with positive and negative charges approach to a certain extent, electrostatic attraction F=QQ/R’ is generated. This force attracts multiple charged particles together, forming agglomeration. The finer the particles, the more serious the agglomeration, and the more difficult the depolymerization.
The specific effects of different water ratios on mill processing of calcium carbonate:
★ When moisture content of the raw material is less than 0.05%, the positive and negative charges accumulated on the surface of the particles cannot be quickly neutralized, and the agglomeration caused by electrical attraction cannot be fundamentally solved.
★ When the moisture content is gradually increased to about 1%, affected by high temperature in the mill, the water is vaporized and dispersed in the air together with the particles. When two charged particles collide, due to the conductivity of water, the positive and negative charges are quickly neutralized, and no obvious agglomeration will be formed.
★ While when moisture content of the raw material increases to over 3%, the vaporized water molecules are adsorbed on the surface of tiny particles. Even though they can quickly neutralize the positive and negative charges on particles, and avoid electrostatic agglomeration, the excess water will wrap the particles and form a thin water film. This layer of water film, affected by surface tension, would act like adhesive to re-bond the particles.
Conclusion
From the above we can see, during processing of heavy carbonate powder, only when raw material maintains appropriate amount of water can the mill run better.
There are many kinds of mills for producing powders, including: impact mill, jet mill, валковая мельница, vibration mill and ball mill etc. Qingdao Epic Powder Machinery Co., Ltd, a professional powder machinery manufacturer, can produce numerous mills for powder grinding.
If you have relevant needs, please feel free to contact Qingdao Epic.
Below are several mill from Qingdao Epic for your reference.
