Cement grinding aids for cement production and grinding aid
The beneficial effects of scientific and rational use of cement grinding aids on cement production: (1) Improve grinding efficiency, increase bench production, and reduce power consumption. This is the most direct effect of using cement grinding aids. Since the grinding aid disperses the particles of the grinding material and increases the fluidity thereof, the grinding medium in the grinding machine strengthens the pulverizing action of the material, thereby improving the grinding efficiency and increasing the production time of the cement. At the same time, the relative power consumption is reduced. (2) The amount of clinker is reduced, and the amount of mixed materials is increased. Since the grinding aid can increase the fine particle content and a part of the grinding aid material itself to promote the hydration of the cement, the cement strength performance can be improved. Therefore, compared with the original cement without the aid of grinding aid, the amount of clinker can be reduced and the mixed material can be incorporated to achieve the same cement grade requirement. (3) Improve cement properties such as strength, setting time, rheological properties, etc. Grinding aids are usually a combination of several surfactants. In addition to grinding, these materials often change the particle size and particle morphology of the cement and affect the hydration process of the cement. Thus showing the strength of the cement, the setting time,
Changes in performance such as liquidity. (5) Reduce CO2 emissions. CO2 emissions from cement production are mainly derived from calcination of limestone, coal for calcination, and coal-consuming electricity. Therefore, the grinding aid increases the amount of mixed materials and reduces the power consumption, which can greatly reduce the CO2 emissions from cement production.
(4) Reduce costs and increase profits. Grinding aids reduce natural costs by increasing grinding efficiency and reducing clinker usage.
The grinding aid effect of cement grinding aids is generally affected by the following factors: (1) the nature of the grinding aid material itself. The main components of the grinding aid are generally surface active substances, and the type and molecular weight of the constituent groups affect the adsorption and dispersion properties of the grinding aid. For example, the effect of monohydric alcohol organics is not obvious, while the polyol organics have better grinding effect. The more the number of hydroxyl groups, the better the grinding effect; the alcohol amines can significantly reduce the cement residue and the number of hydroxyethyl groups. The increase will increase the fluidity of the cement. (2) The amount of grinding aid. The actual amount of grinding aid is generally low, depending on the type of grinding aid and the grinding aid efficiency, which is about 0.01% to 0.10%, which is less than the standard limit of 0.5%. Each grinding aid has its optimum dosage range. If the amount is too small, the best effect will not be achieved, and excessive addition will not only cause waste, increase cost, but also may cause excessive grinding and wear between the grinding media due to excessive fluidity of the powder. Decreasing the grinding efficiency has an adverse effect on the quality of the cement. The current view is that , when the single-molecule adsorption film is formed on the surface of the fine particles, the amount of the addition should be the most reasonable amount of the grinding aid.