The Thermal Conductivity of Magnesite, Dolomite and Calcite as Determined by Molecular Dynamics Simulation

Abstract

In this study, the phonon-based thermal conductivity of magnesite (MgCO3) and dolomite (CaMg(CO3)2) is calculated and compared with an earlier recent calculation on calcite (CaCO3). Equilibrium molecular dynamics simulation by way of the elegant Green-Kubo formalism is used for calculating the thermal conductivity. The thermal conductivity is investigated over a wide temperature range (from 200 K to 800 K) for all of the above mentioned materials. The most reliable potential parameters are used for characterising the interatomic interactions. In all of the models, two independent mechanisms are considered. The first is temperature independent, which is relevant to the acoustic short-range and optical phonons, and the other is temperature dependent, which is linked to the acoustic long-range phonons. In the study, the heat current autocorrelation function (HCACF) is calculated over the averages of the NPT, NVT and NVE ensembles in the x- and z- directions. In addition, it is shown that the optical, acoustic short- and long-range phonon modes are the main contributors to the decomposition model of the thermal conductivity. In a further investigation, the effects of the computational cell sizes on the thermal conductivity are investigated with five different simulation blocks containing 30, 240, 810, 1920 and 6480 atoms. Finally, this research provides a comparison of the thermal conductivity from this study and experimental studies: they are in good agreement.

Molecular Dynamics Simulation of Forsterite and Magnesite Mechanical Properties: Does Mineral Carbonation Reduce Comminution Energy?

“…This potential is a bond-order and short-range interaction-based potential which is attributed to the partial charge of the atoms. Several prior studies have used this potential to reproduce the structural properties of both forsterite and magnesite polycrystals [30,31]. The Buckingham potential can be expressed as follows:…”

Study of the thermal conductivity of natural carbonates

“…Исследованию теплопроводности природных карбонатов посвящены работы [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16]. Теоретические расчеты приведены в [17]. Однако в найденных нами публикациях приводятся значения коэффициента теплопроводности при комнатной температуре или рассматривается поведение теплопроводности как горных пород, так и кристаллических кальцита и доломита, при повышенных температурах.…”

Separation of magnesite and calcite based on flotation solution chemistry

“…Sodium oleate is a commonly used anionic collector with strong collection capacity with poor selectivity for many minerals, including magnesite . Other traditionally used fatty acid type collectors have similar limited selectivity (Gao et al, 2015;Momenzadeh et al). Tang et al analyzed the surface chemistry of magnesite and calcite in a potassium cetyl phosphate flotation system and observed strong displacement of the zeta potential of the adsorbed magnesite in the negative direction (Tanget al, 2020).…”