Transformacja muskowitu w kaolinit w złożu kaolinu Andrzej w Żarowie

Abstract

Przedstawiono wyniki badań łyszczyków z kaolinu rezydualnego złoża Andrzej w Żarowie, które obejmowały analizę granulometryczną, rentgenograficzną, termiczną oraz chemiczną. Badania wykazały, że kaolinit powstał nie tylko na drodze kaolinityzacji skaleni, ale również przez równolegle przebiegającą transformację muskowitu.TRANSFORMATION OF MUSCOVITE INTO KAOLlNITE IN THE ANDRZEJ KAOLIN DEPOSIT AT ŻARÓWThe Andrzej residual kaolin deposit from Żarów originated in result of kaolinitization of Strzegom granitoid. Samples no. 1 and 2 were taken in lower, the least alterated part of the deposit sample no. 3 - in upper part and sample no. 4. in top most strongly alterated part Table 1 shows granulometric composition of the samples. The studies covered micas separated in natural way from regolith and those separated from fractions over 250, 250 – 125, 125 – 63, and below 2 μm of the samples no. 1 and 2. X-ray studies showed that micas yield admixtures of muscovite kaolinite and quartz (Table 2). The share of kaolinite increases proportionally with decrease in size of mica grains. The increase in share of kaolinite may, according to the present author, be explained by transformation of muscovite into kaolinite. The process of transformation and simultaneous diminution of muscovite is accompanied by removal of Na, Mg, K, Fe, V, Zn and Sn (Table 3). Gradual transformation of muscovite into kaolinite takes place with retaining of external macroscopically noticeable features of the former, including luster, outline and cleavage.