SILICA DISSOLUTION AT LOW pH IN THE PRESENCE AND ABSENCE OF FLUORIDE

SiO2 is the most abundant oxide in the earth and its properties, behaviors and interactions are of immense scientific and technological importance. Of particular importance are the interactions of silica with aqueous fluids because these fluids are present in nearly every natural setting. The dissolution of silica and glass by HF plays a very important role in technology and is widely used for the etching of silica and silicate glasses in the glass industry, in the flint industry, in surface micromachining, in etching of glass fibers for near-field optical probes, in the creation of frosted surfaces for decorative applications like frosted glass and cosmetic vials. I performed 57 batch reactor experiments in acidic fluoride solutions to measure the dissolution rate of quartz. Quartz dissolution rate data from other published studies were combined with the rate data from my experiments and these 75 data were analyzed using multiple linear regression to produce an empirical rate law for quartz € rqz =10 −4.53 e −18932 RT       aHF a H + −0.39