Evaluation of boron wastes in aerogel production

In this study, the borax slime (slurry) waste supplied from ETİ maden A.Ş. containing sodium content was used as raw material and the aim was to produce borasilicate aerogels by left-gel production tecnique. The aim of this study is to increase the industrial usability of boron waste. In order to change the grain size of the raw material and accelerate chemical reactions 0h, 1h and 2h mechanical activation process was applied to the starting powder. Thus 0h, 1h, 2h activated borax slime waste within left-gel production technique; the left-solution was obtained in solution with HCl acid and gelling was formed by the addition of NaOH base catalyst. After gelation occured, it was subjected to the maturation stage and then, by using various chemicals, unwanted materials was removed from the gel, as a result the strength of bond structure of the gel was increased. Borasilicate airgel powders were synthesized by using atmospheric drying and freezing dryer techniques. The synthesized aerogel powders were characterized by XRD, SEM, FESEM, EDS, FTIR, particle size analysis and thermal conductivity measurement analysis. As a result of the analyzes, it was observed that there was a high amount of pores in the structure of borasilicate airgel powders and consequently a high value-added insulating material with low density, good powder flow, B-Si and B-O bonds and good thermal conductivity coefficient is obtained. Keywords: Borasilicate aerogels, left-gel production technique, mechanical activation