Quantitative determination of respirable quartz in bulk samples of organoclay by combined air classification / x-ray diffraction
✍ Scribed by Lawrence E. Morgan; L. DiCarlo
- Publisher
- Elsevier Science
- Year
- 1994
- Tongue
- English
- Weight
- 526 KB
- Volume
- 286
- Category
- Article
- ISSN
- 0003-2670
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✦ Synopsis
There are a multitude of sampling techniques and quantitative methods for respirable silica in airborne materials but no sampling techniques exist to determine respirable silica in bulk samples. In order to determine the respirable quartz portion in an organoclay, a scheme was devised to employ air classification to separate the fines or respirable portion from the non-respirable or coarse portion. We chose < 10 pm material to represent the respirable portion. The total quartz content of the organoclay was determined on the "as-is" bulk sample by x-ray diffraction (XRD), using standards prepared in the laboratory and matrix matched to the organoclay being analyzed. The organoclay was then passed through an air classifier and separated into two fractions. Both the fines ( ( 10 pm organoclay) and the coarse (> 10 pm) portions were analyzed by XRD for percentage of crystalline silica. Preliminary results appear encouraging in that air classification can separate respirable material and XRD is capable of measuring quartz quantitatively to the < 1% level.