Możliwości zastosowania metody Scheiblera w badaniach zawartości węglanu wapnia w litych skałach węglanowych

Abstract

This paper presents the opinion of application of the pedological Scheibler method in estimation of the CaCO[3] from cemented carbonate deposits. The Scheibler method belongs to volumetric analysis in which content of СаСO[3] is calculated from volume of emitted carbon dioxide as a consequence of reaction of the rock sample with HCl. Investigations are realized using Scheibler apparatus - fig.1. - taking the readings of CO[2] volume from the measuring pipe. Percentage calculation of carbonate content is calculated on the base of formula "1". Marls and limestones from middle Cretaceous profile in Stare Bystre (Pieniny Klippen Belt) were exposed to the action of this method - fig. 2. Results of researches have been listed in tab. 1. In order to verify the correctness of these results, thermo- gravimetric analysis has been done for ten selected samples. On the basis of TG and DTA curves the content of calcite has been estimated. Calcite have suffered desintegration in temperature 850-900°C, during warmig up. It was strong endothermal reaction (fig. 3). The results of these investigations and their comparison with results based on Scheibler analysis have been compiled in table 2 and fig. 4. In this comparison concurrence of results from these methods for light (oxidized) deposits is well visible. However the value of the findings from Scheibler method are a little higher (6,8%) for dark grey and dark deposits. This is effect of additional CO[2] cummulation of sulphuretted hydrogen (H[2]S) which created as a result of HCl reaction with sulphides. Consequently, this surplus is approximate content of sulphides in the rock. The above mentioned results give possibility to adopt Scheibler method in researches of this type of deposits. This way, time-consuming and expensive indications of СаСO[3] by thermogravimetric, chemical and others methods can be successfully replace by this one.