Evaluation of wste silica precipitated in the process of hydrofluoric acid production from fluosilicic acid
More details
Hide details
Poznan University of Technology, Institute of Chemical Technology and Engineering
Poznan University of Technology, Institute of Chemistry and Technical Electrochemistry
Andrzej Krysztafkiewicz   

Poznan University of Technology, Institute of Chemical Technology and Engineering, M. Sklodowskiej-Curie 2 Sq., 60-965 Poznan, Poland
Publication date: 2005-01-01
Physicochem. Probl. Miner. Process. 2005;39(1):165–176
Studies were performed on the potential for purification of silica, precipitated as a by-product in the course of hydrofluoric acid production, and its possible use as an elastomer filler. The process underwent in the fluosilicic acid-sulphuric acid system. The silica surface-occluded water soluble fluoride compounds were washed off in hot water, on vacuum filters. The obtained product manifested much better physicochemical parameters (i.e., more pronounced white colour and augmented specific surface area) as compared to raw silica. Moreover, the waste silica following leaching with hot water (at its boiling temperature) exhibited a favourable particle size distribution and contained no agglomerate structures. The purified silica was employed as a filler in mixtures containing butadiene-styrene rubber. The obtained vulcanisates showed advantageous physicomechanical parameters (high tensile strength and high modulus).