Preparation And Application Performance Of Multifunctional Composite Additive Bao Gan

Productions of ceramic industry is generally divided into three procedures: rawmaterial processing, molding and sintering. And ceramic additives is indispensable inevery step. This thesis, based on Bao Gan mineral soil of Pingchuan district, aimed atdeveloping a new kind of additive with multifunctions of dispersion, water reduction,grinding and strength enhancement, which provides technical support for developinghigh performance ceramic production utilizing the soil resource of PingChuan district.This thesis firstly studied the effect of different commercial additives on theflowing properties of Bao Gan raw material and formulate composite additive withsodium tripolyphosphate (STPP), sodium polyacrylate (PAAS), humic acid sodium(HA-NA) and modified layered crystalline sodium disilicate (MLCSD), based on theevaluation of their grinding and strength enhancement for raw material. Then, thedispersion, grinding and strength enhance performance of Bao Gan raw slurry in thepresence of the additive was further systematically studied and corresponding resultsindicated that raw slurry had the best performance when the ratio of each component(STPP, PAAS, HA-NA and MLCSD) was3:1.5:3.5:1, the slurry had the shortestflow-out time (41.9s) and best thixotropy (1.48) with moderate viscosity (249.1mpaï¹'s) when adding ratio of composite additive is0.25%, which greatly improved theprocessability of the Bao Gan slurry. Meanwhile, when adding ratio is0.35%to0.40%, the additive owned the best grinding and strength enhancement performance,resulting in mechanical property improvement of Bao Gan products with sieveallowance and bending strength being2.411%,3.82MPa, respectively.Comprehensive characterization for the composite additive had also been carriedout: Infrared Absorption Spectrum (IR) and X-ray diffraction (XRD) were utilized todetermine the composition and structure of the additives while the influence to theslurry system by the solution pH was revealed by Zeta potential measurement.Particle size, distribution and morphology in Bao Gan slurry and fracture section ofthe production were detected by particle granularity analysis and scanning electronmicroscopy (SEM). In the end, optimum sintering temperature was determinedthrough comprehensive thermal analysis (DSC and TG). Results indicated that in the presence of the multifunctional composite additives, the particle size was obviouslydecreased due to better grinding performance. Meanwhile, with well mixing of eachcomponent and fully sintering, molten glass phase, which was more stable, wasformed in material, yielding more smooth fracture section surface and few apertures.The analysis and mechanism also provides theoretical basis for mechanical propertyimprovement of the Bao Gan ceramic productions with the composite additive.