the Effectiveness of the Grinding Aid

Grinding aids are generally  the surface-active substances, has the features of reducing the role of surface energy and particle cracking"wedge". When the material in the fine grinding process, the particles gradually refined , the surface area is increased, due to bond breaking,the surface is charged , particles adsorb to each other and reunite, so that the grinding efficiency declines. After adding a small amount of grinding aids, we can prevent particle reunite and improve material mobility, thereby improving the milling efficiency, and short the grinding time. Such as when the aluminum oxide is experienced dry grinding ,add an appropriate amount of oleic acid, wet grinding a small amount of aluminum chloride. Grinding ordinary ceramic material by adding a certain amount of sulfite pulp waste. A wide range of grinding aids vary with the grinding material, generally is polymer: pairs Kay polymer polyols, Bo polyol amine, triethanolamine, etc. for the material of choice. For cement grinding aids,it can be defined as:  improve the material grindability of the cement processing performance, and improve the grinding efficiency of the mixing amount of not more than 0.5% a or more surface active substances.

 

The  effect of grinding aids have several effects. Among them, the grinding aid of the rotary kiln clinker's effects is the  best ,the fineness can be increased by 40.0%. But the grinding effect of slag and stone cinder is general. This is due to the difference nature of their material. Rotary kiln adopts the grate cooler cooling clinker and clinker from the firing zone out immediately by the second cooling air cooling, the temperature difference is good, the cooling rate speed is faster. A mine edges and corners is complete, the B ore is mostly spherical particles, the intermediate distributes more uniform,  vitreous is more, due to the different coefficient of thermal expansion of clinker each phase, and differences in the pace of change of the polycrystalline, rapid temperature changes, the phasic contraction uneven thermal stress resulting particles are prone to micro-crack.
 In the presence of the grinding aids, grinding aids molecules to penetrate into the crack inside,  break the crack-tip stress concentration and crack side, destroy the chemical bonds between atoms, leading to crack growth, until fracture. The slag is a good potential activity of the material, slag activity is related to the chemical composition, but depends on the cooling conditions. Quench water quenched prevent the mineral crystallization, thus giving rise to a large number of active amorphous vitreous structure or network structure, has a high potential activity. But a variety of mineral crystal structure of clinker, and slag by the same vitreous composition, microcracks than clinker, and thus the better the effect of grinding aids. By 1 # 2 # cement Looking at the results, after mixing BWJ grinding aids, fineness decreased by 13.3%, 14.3%, and 28 days compressive strength were improved 5Mpa 4.2Mpa. This shows that  the BWJ grinding aids has better adaptability to different materials.