A Preliminary Study On Phase Transformation Of Coal Ash Under Water-Biochemical Condition

Coal Ash and city sewage sludge are two sources of pollution in cities. Founding on the former researches on the coal ash and the city sewage sludge, it is of important significance to study on the condition and the mechanism of both of them as soil additive.Coal ash has the similar ingredients with clay minerals and different phase. On the theory that non-crystal can transform into crystal in a certain condition, coal ash transforming into clay minerals is expected. In spite of different treatment of sewage and different microbial population, a plenty of microbial in the city sewage sludge could change the parameters indicating liquid surroundings such as pH value and oxidation-reduction potential. So it is of practical significance to explore the phase transformation of coal ash by using the microbial in the city sewage.So a simple shaking-dissolving experiment was designed: Mix the coal ash with the filtrated liquid at a certain proportion and kept shaking on the cycle-shaker. During the course of reaction pH value was measured and the phenomena was observed. Six months later, drying part of the samples in conical flask and taking the test of SED, EDS, XRD etc.The experiment results showed as follows: the microbial produced acid inflected the pH values of the high alkaline coal ash, so the acid surroundings condition provided transformation condition. Then a lot of new chlorides found on the rim of the sphere of the coal ash. The test of XRD showed the identical peaks of 4.41-4.53 of clay minerals, that to meant the existence of the clay minerals. An impurity peak marked 7.57nm was fond also. Some of new halogen salt came into being just on the surface of glass sphere.The shaking-dissolving experiment results indicated that it is of latent source value to benefit the soil by composite of coal ash and city sewage.