Thermal behavior of natural dolomite

Abstract

The thermodynamic analysis of the thermal decomposition reaction of carbonates showed that the temperatures of thermal stability of dolomite and magnesium carbonate are very similar. Kinetics of isothermal and non-isothermal decompositions of natural dolomite in air atmosphere were investigated. Under the examined conditions, dolomite decomposed in a one-stage process. The final solid products of dolomite's decomposition were calcium and magnesium oxides. The average value of isoconversional apparent activation energy of non-isothermal decomposition was 205.60 kJ mol -1 . The kinetics of decomposition can be described by the power-law model P2/3 with ln(A) = 20.98 for the extent of reaction a \ 0.77 and by two-dimensional diffusion model D2 with ln(A) = 21.12 for a [ 0.77.

Diammonium Hydrogenphosphate Treatment on Dolostone: The Role of Mg in the Crystallization Process

“…For this reason, untreated and treated specimens were initially analyzed at room temperature (rT); after that, the samples were heated at 400, 600 and 900 • C, and re-analyzed at rT after each heating process. The selection of the temperature steps used to investigate the T-induced "parent-to-product" phase transformation is driven by literature data [9,16,[31][32][33][34][35][36].…”

“…The heating at 600 • C acts on poorly-crystalline calcium phosphates, as the weak broad peak at~25.90 • of 2Theta becomes more pronounced. The principal phase transformation occurs after heating at 900 • C, where dolomite of the substrate is decomposed into magnesium oxide (MgO, peaks at 42.92 • and 62.30 • ) and lime (CaO, peaks at 32.27 • , 37.48 • and 53.97 • ; phase transformation probably occurred between 600-820 • C [33,34]) and the peaks of calcium phosphates become more defined. More precisely, the growth of sharp, well-defined peaks at 2Theta of 25.90 • (d 002 ), 31.77 • (d 211 ), 32.96 • (d 300 ) and 34.08 • (d 202 ) unambiguously identify crystalline HAP as heating by-product.…”

Synthesis and homogeneity range of Yb8−xYxV2O17 in the Yb8V2O17–Y8V2O17 system

“…The DTA method for testing the thermal stability of the various phases forming in the multicomponent oxide systems was described, inter alia, in [30][31][32][33]. Selected samples were investigated also by means of an electron scanning microscope-SEM (JSM-6100, Jeol, Japan).…”

Flammability, Thermal and Mechanical Properties of Polybutylene Terephthalate/Dolomite Composites

“…The decomposition of dolomite is an endothermic reaction, in which the reaction absorbs heat energy by producing metal oxides (CaO and MgO) and releasing CO 2 , hence slowing the spread of fire. 16,17 The release of CO 2 also dilutes the oxygen concentration in the atmosphere and further slows the spread of fire. 17,18 The small improvement is considered good since the amount of dolomite is also small, i.e., up to 15 wt%.…”