An analysis of the chemistry, mineralogy and texture of waste dolomite powder used to identify its potential application in industry

Abstract

In this work, characterization of dolomite powder was carried out in order to specify possible industrial applications. After the technological use of dolomite aggregates, the remaining fine powder becomes a waste. Raw and calcined powder samples were subject to mineralogical, textural and chemical studies involving leaching tests. The results of the calcination process indicate that the carbonate minerals present in the material sample undergo complete decomposition to form oxides. After the calcination, the material is practically non-porous, and its surface area is more than five times lower than that of the raw material. However, due to the high content of calcia in the calcined sample (CaO > 45% wt.), the material cannot be used as an additive in cement. The leaching tests showed that the concentration of metals released from the dolomite powder is low enough to classify the material as hazardous waste according to the TCLP test. Moreover, the concentration of metals that can get into the environment does not exceed permissible values as set by Polish law. Thus, it is recommended and justified to carry out detailed tests for the purpose of environmental protection, i.e. wet flue gas desulfurization, heavy metals absorption, and $CO_2$ capture.