The Performance Of Mixed Limestone Cement Under Respectively Grinding And Common Grinding

In recent years, the demand of mixed material in cement industry is increasing,but the traditional mixing materials, such as slag, fly ash is increasingly scarce, the natural resources of limestone as a kind of large storage capacity, cheap and easy to obtain will has great economic value and use prospect. Mixed with proper amount of limestone, can improve many performance of cement such as enhance early strength, reduce the hydration heat, increase liquidity, and improve the compactness, but currently the vast majority of cement enterprises use common grinding way to preparation of limestone cement, and because of different grinding performance,this kind of grinding process for limestone and cement clinker grinding use to have obvious selectivity grinding phenomenon in the process of grinding, It is necessary to study that under the condition of common grinding and grinding respectively the limestone cement particle distribution and its influence on the properties of cement hydration process, and that will have important practical significance to guide the actual production process in the future.This paper used the laser particle size analysis, thermal comprehensive analysis, the hydration heat analysis, XRD and SEM test technology, Firstly studies the rule of Portland cement hydration rate, as a compare parameters for further research analyses the differences performance of limestone cement under common grinding and respectively grinding. The results show that:Clinker hydration depth and its hydration ages present a well logarithm relationship, cement early hydration depth is about 3.5μm, the depth of the middle and later hydration in 5.10 to 6.39μm, the hydration depth of long age is about 9μm; Separately grinding system can reasonably control the distribution of limestone cement particles, and lead clinker to the finer particles scope,and improve the grinding efficiency; In conditions of the same energy consumption, the compressive strength, liquidity and hydration rate of respectively grinding limestone cement is superior to the common grinding limestone cement; Thin limestone powder can promote the early hydration reaction of cement, the hydration rate of later period mainly depends on the fineness of clinker particles; At the same age, limestone cement under reasonable respectively grinding preparation will have more hydration products,and the hydration products’link will be closely, cement structure is more dense as a whole.