Siliceous earth resembles diatomites in physical features and, therefore, finds similar use in the industries. It is used as carrier for catalysts in chemical processes and for mineral fertilizers and herbicides, pesticides and fungicides in agriculture as well as raw material for refination and filtration and constituent of synthetic moulding mass. Siliceous earth differs from diatomites in the mode of origin as it is the product of decalcification of opoka sedimentary rocks and mainly built of opal, a mineraloid gel.
Deposits of siliceous earth occur mainly in tectonic troughs at the margin of the Holy Cross Mts (Piotrowice and Dąbrówka deposits) and in the Lublin Upland (Lechówka deposit), in the form of sedimentary covers overlain by Oligocene rocks.
Table 1 shows resources and the current state of exploration and development of siliceous earth deposits in Poland.
Anticipated economic resources amounted to 2,223 thousand tonnes in 2013. Nowadays there is concession for exploitation issued only for Lechówka II deposit. This deposit is exploited temporarily, in 2013 raw material was not exploited.
Prepared by: Robert Bońda