Natural Mineral Particles extraction in filters from Gran Canaria dust collectors

Abstract

In this study, a humid-ultrasonic method of Saharan dust particles extraction from the collecting filters was set-up. Saharan dust samples were collected in cellulose filters (Whatman 41) with high volume dust collectors installed on Tafira Baja Campus. Two ultrasonic-humid extraction cycles were carried out. Subsequently, an image analysis (ImageJ program) was carried out, from a Leika MZ6 stereomicroscope photographs. The particle identification and parametrization (area, perimeter and circularity) were used to calculate the Saharan dust concentration, the cumulated grain size distribution curves, and the statistical parameters (mean size, sorting, skewness and kurtosis) with Gradistat V9.1 program. As study results it can say that the optimal time of cellulose filter extraction is less than 20 minutes; that the ultrasonic-humid extraction method could be consider texturally stable; that the more sample weight, the more sequential extractions could be obtained; and respect to the Saharan dust texture, the mean particle size was coarse silt, the sorting was poorly, the skewness very negative and, the kurtosis very leptokurtic. Furthermore, this extraction method for Saharan dust particles had not been studied before from this type of cellulose filters and will facilitate textural and mineralogical future studies.