Determination of Quartz

Abstract

Differential thermal analysis (DTA) was evaluated for the determination of quartz after comparing it with other methods now in use. The effect of particle size on peak height was studied by preparing calibration curves for sized quartz in silicon carbide (SiC). It was found that thermal response decreases with decreasing particle size, indicating the necessity for size analysis of unknown samples. Commercial talc and granite samples were analyzed for quartz after size determination and dilution with 30% SiC. Results were found to compare favorably to those obtained by phosphoric acid digestion. Foundry samples were similarly analyzed after preheating to combust carbonaceous material. These settled dusts were also analyzed using standard addition and internal standard techniques. X-ray diffraction analysis was used for comparison with the thermal procedures and agreement was found between the x-ray and DTA results.