Study On Improving Activity Of Natural Anhydrite

Natural anhydrite is rich in naturnal resources, but activity is very low and gelatinization property is not good. Its utilization ratio is not high and so vast scale of abolition, lead to great enviromental contamination and great resource waste. Considering energy conseration and protect the environment against pollution and to increase economic efficiency and to enlarge the raw material source of construction. It become urgent affairs to appripriately and effectively utilize the natural anhydrite resource. By increasing the activity to produce various construction materials and products is a important technology measure to improve present state and a effecive way to improve utilization ratio.The composition, structure and hydration properties of natural anhydrite were analysed. Activity and the way how to improve it are studied, too. The process to improve the activity of natural anhydrite such as grinding, the effect of grinding aid, incineration and excitation by sulphate, and so forth are the focal points in this article. By means of research technology such as SEM ,XRD, the crystal shape of gypsum in anhydrite hardenite and crystal structure of heated anhydrite. Experiments indicated that if fineness is invariable, the natural anhydrite has hydration-hardening property, but because of the low solubility, its degree of hydration and strength are low. The soluble salt which containing in natural anhydrite may accelerate its solution and crystallization.the gypsum have seed crystal effect and be able to induce re-nucleation. The seed crystal in addition is able to accelerate early hydration and nucleation of natural anhydrite. And it has no obvious influence on final hydration. If the amounts of seed crystal exceed the limit, the acceleration will exhibit fall tendency. Temperature has large influence on solution and hydration ratio of natural anhydrite. In the low temperature circumstance, the degree of supersaturation of solution is high, so crystallization is easy to occur. As the temperature rises, the hydration ratio is falling. Therefore, it is not suitable for natural anhydrite to hydrate and curing in too high temperature.If natural anhydrite in the acidic circumstance, the degree of solution is high and degree of supersaturation is big, it is good for crystallization. If gypsum is in the acidic circumstance, its solubility will increase higher than in the ordinary circumstance. It is harm to degree of supersaturation. So the acidity shouldn't too big and it is necessary to...