Method for preparing high-calcium fly-ash cement with high-calcium fly-ash

Abstract

The invention discloses a process for preparing high calcium fly ash cement by high calcium fly ashes. A combustion chamber is arranged at the head part of the existing ball mill for pre-mixing measured high calcium fly ashes and a digesting agent and then feeding measured cement clinker, gypsum, blast furnace slag, etc. into a ball mill for ball grinding; and the material temperature in the mill is rising under the mechanical action of the mill, additionally, the grinding head combustion chamber provides heat, so the water in the digestion solution is evaporated and the digestion solution and free calcium oxide in the high calcium fly ashes have the mechanical and chemical action, the free calcium oxide digestion is realized during the cement grinding process, and finally the high calcium fly ash cement is prepared. The process is simple and needs not to add the special high calcium ash treating process before producing the cement, the free calcium oxide digestion effect is obvious, the mixing amount of the high calcium ashes in the cement can be greatly increased and the cement manufacturing cost is reduced. The process overcomes the defect that the humidity-control and digestion of fly ash free calcium oxide need two to seven days, and can implement the continuous production, and the ball-milling efficiency of the cement mill is improved by over 10 percent in the meantime.

Description

technical field [0001] The invention relates to a preparation method of fly ash cement, in particular to a method for preparing high calcium fly ash cement with high calcium fly ash. Background technique [0002] As we all know, the fly ash with calcium oxide content greater than 10% (weight) in the fly ash is called high calcium fly ash. Because high calcium fly ash contains free calcium oxide, if it is directly used in cement and concrete, it will often cause unqualified volume stability of cement or concrete, and bring hidden dangers to construction projects. The content of free calcium oxide in ash is strictly limited. According to the national technical standards on high-calcium fly ash, most high-calcium fly ash cannot be directly added to cement or concrete, and high-calcium fly ash needs to be modified. [0003] According to relevant national standards, the hydraulic cementitious material made of Portland cement clinker, fly ash, and appropriate amount of gypsum is...

AI Technical Summary

Problems solved by technology

The outstanding feature of this method is the high cost of the added chemical substances, resulting in the high cost of modified fly ash

[0008] There is also a method of humidity control treatment, which is simple and low in cost, but the process of fly ash humidity control is not easy to operate, and there are defects such as it is not easy to realize the automatic operation of environmental protection in the process, which brings difficulties to large-scale production.

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