Study On Preparation And Properties Of Ceramsite With Non-Metallic Minerals

Ceramsite is a kind of artificial lightweight aggregate. It usually could be calcined at high temperature with shale, clay rock and industrial waste, which should be crushed, screened and granulated. It has light-weight density, high-strength, good thermal insulation performance, low engineering cost, good chemical stability and the other advantages. Generally, Ceramsite are widely used in lightweight construction materials, soilless cultivation and sewage treatment and other fields.In this thesis, a non-metallic minerals ceramsite was prepared at high temperature with perlite, kaolin, bentonite, zeolite and tuff as the main raw materials, adding moderate foaming agent and fluxing agent. Effects of the sintering process and the foaming mechanism on the properties of ceramsite were investigated. The research works includes the following aspects:(1) The main raw materials, additives, foaming and fluxing mechanism, preparation method were analyzed and investigated. The suitable raw materials, additives and technological processes were determined;(2) Effects of preparation conditions on the properties of products were studied, such as the proportion and mixing time of raw materials, the foaming agent and fluxing agent dosage, preheating temperature, preheating time, calcination temperature and time by the single factor experiment method. The parameters of the influencing factors were preliminarily confirmed;(3) Influences of calcination temperature, calcination time and the foaming agent dosage on the properties of ceramsite were studied through the orthogonal experiment, the combination of parameters were also optimized.(4) The tuff ceramsite with light-weight and high-strength properties was prepared by optimizing the foaming agents and fluxing agents dosage. The optimal conditions for the preparation were attained with tuff as main raw material.(5) Characterizations of the ceramsite product have been performed including density, strength, structure and chemical composition.Favorable performance of the non-metallic minerals ceramsite can be achieved through the optimized preparation conditions, including perlite, kaolin, bentonite, zeolite and tuff proportion of3:2:3:1:1, the mixing time of20min, SiC content of1.0%, MgO dosage of1.0%, preheating temperature of450℃, preheating time of15min, calcination temperature of1200℃and calcination time of10min. For this sample, the granule density was0.4813g/cm3, the granule strength was602N. Perfect performance of the tuff ceramsite can be attained through the optimized preparation conditions, including the tuff content of80%, the mixing time of20min, SiC content of1.0%, fluorite content of2.0%, calcination temperature of1200℃and calcination time of10min. For this sample, the granule density was0.4680g/cm3, the granule strength was574N. According to the method of the GB/T17431.1-2010, the cylinder compressive strength of the non-metallic minerals ceramsite and the tuff ceramsite was measured as10.86MPa and9.734MPa, respectively.The composite ceramsite with light-weight and high-strength was prepared by high temperature fast firing with non-metallic minerals. This study not only utilizes ore resources comprehensively, but also prepares a ceramsite with light-weight and high-strength properties. This ceramsite product can be extensively applied in construction indusity.