Cleaved surfaces of dolomite were studied using ex-situ X-ray photoelectron spectroscopy (XPS) following exposure of the surfaces to various experimental conditions. Dolomite samples exposed to air, to a highly undersaturated solution (0.1 M NaCl, pH = 9), and to solution with a supersaturation ( Dl/kT) of 5.5 (pH = 9) were investigated with semiquantitative methods of analysis to ascertain the...

Magnesium oxide suitable for the use in basic refractories was prepared from dolomite (CaMg(CO3)2) by hydrochloric acid leaching, precipitation with CO2 and thermal hydrolysis. Leaching of the dolomite ore in aqueous hydrochloric acid solution was investigated with respect to the effects of time on dissolution of the dolomite sample. The dependence of the observed dissolution rate on pH was est...

Recent solubility, electrokinetic, spectroscopic and flotation studies in our laboratory on apatite and calcite in aqueous electrolytes indicate complex mineral_olution interactions which can alter surface characteristics of these minerals markedly in the presence of each other. In the case of systems containing such sparingly soluble minerals, understanding of the mineral_olution chemical equi...

Thermal decomposition of dolomite in the presence of CO2 in a calcination environment is investigated by means of in situ X-ray diffraction (XRD) and thermogravimetric analysis (TGA). The in situ XRD results suggest that dolomite decomposes directly at a temperature around 700 °C into MgO and CaO. Immediate carbonation of nascent CaO crystals leads to the formation of calcite as an intermediate...

introduction: recently, air pollution due to the occurrence of dust storms is one of the worst environmental problems in western and southwestern iran, especially the khuzestan province (12, 13). according to the reports of the meteorological organization of iran the average number of dusty days in the cities of ahvaz and abadan in the khuzestan province reaches 68 and 76 days each year, respec...

Reflectance spectra of carbonate minerals in the shortwave infrared (SWIR) and thermal infrared (TIR) wavelength regions contain a number of diagnostic absorption features. The shape of these features depends on various physical and chemical parameters. To accurately identify carbonate minerals or rocks in pure and mixed form, it is necessary to analyze the effects of the parameters on spectral...

Abstract—Surface characteristics of Bacillus megaterium strain were investigated; zeta potential, FTIR and contact angle were measured. Surface energy components including Lifshitz-van der Waals, Hamaker constant, and acid/base components (Lewis acid/Lewis base) were calculated from the contact angle data. The results showed that the microbial cells were negatively charged over all pH regions w...

Principal component regression (PCR) was used to develop calibration and prediction models for determination of mineral content of complex mineral mixtures by utilizing attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectra. The typical constituents of oil shale such as dawsonite, nahcolite, quartz, dolomite, illite, albite, analcime, and kerogen were used to prepare samples...

The paper reports on a current research on fluidised bed gasification of biomass and coals. The focus is on the bed material agglomeration and fragmentation phenomena that are well known to affect the reliability and the efficiency of fluidized bed combustion processes. Preliminary results of dedicated tests at high temperature are reported and discussed in the paper. On the whole, agglomeratio...