Diatomites are firm sedimentary rocks mainly built of diatom skeletons composed of amorphous silica – opal. A closely related mineral raw material is diatomaceous earth, a loose rock. Diatomites and diatomaceous rocks are widely used as a filtration aid, absorbents for liquids, carriers for herbicides and fungicides and contact agent carriers in chemical industry. They are also used as thermal insulators and a mild abrasive. Up to the present, no typical diatomites with SiO2 content over 80% have been found in Poland. Therefore, despite of differences in origin and mineralogical composition, siliceous earth is treated as a substitute of diatomites and diatomaceous earth. The siliceous earth is discussed in a separate section of this report.
In the Leszczawka area (Carpathian Mts) diatomite rocks with SiO2 content equal 72% at the average occur in the Menillite Series of the Krosno Beds. Products obtained from that mineral raw material are of fairly limited usability. Their major uses comprise production of light building aggregates and carriers for herbicides and fungicides. It should be noted that technological tests show that appropriate processing (grinding and calcination) may improve quality of this raw material to that of proper diatomites.
Anticipated economic resources of diatomite rocks equal more than 10 million tonnes. Since 2000 there has been only one deposit – Jawornik – exploited. In the year 2015 extraction of diatomite was being carried out at a small scale (0.60 thousand tonnes) (Table 1).
Further detailed and preliminary exploration may markedly increase the hitherto known resources of this raw material. Perspective resources of diatomaceous rock in the Leszczawka area are estimated at about 10 million tonnes. Chances for discovery of new large diatomite deposits seem to be the highest in the case of the Menillite Series of the Krosno Beds in areas of Godowa, Błażowa-Piątkowa-Harta-Bachórz and Dydnia-Krzywe (Podkarpackie Voivodeship).
Prepared by: Robert Bońda