| The production of solid clay brick occupies a lot of land resources and the rapid economic development leads to serious deposition of silt in some areas, both of which are negative to the sustainable economic and environmental development of our country. After publishing the country policy of forbidding using solid clay brick, new building materials are in great need. Therefore, brick making with silt is of important significance.In this thesis, experiments are conducted on chemical dewatering, mechanical dewatering, and brick making. The effects of the type and amount of flocculant on the dewatering of silt are discussed based on the experimental data. By combining with mechanical dewatering through plate and frame filter press and centrifuge, an optimum dewatering scheme is determined and a detailed analysis is made on the dewatering phenomena. Based on the scheme, a reasonable process of brick making is proposed. By measuring various indexes of sintered brick, the effects of admixture and burning temperature on the properties of sintered brick with a low dosage of fly ash are studied and the causes why the specimens fail to meet Chinese national standards are analyzed. The experimental results show that, by adding a same volume flocculant C with a concentration of0.3mg/mL to slit with a high moisture content and dewatering5to10minutes with centrifuge at a maximum speed, a type of silt that satisfies the requirements of transportation can be obtained. Another type of silt with a moisture content close to20%and suitable for brick making can also be obtained by diluting silt into slurry with a moisture content of80%, adding a same volume flocculant C with a concentration of0.3mg/mL, standing for24hours after stirring and mixing fully, and dewatering through plate and frame filter press. With the increase of the dosage of fly ash and burning temperature, the volume density and compressive strength of sintered brick increases but the water absorption rate decreases. |
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