No abstract

The corrosion of refractories by sodium salts in waste liquid at high temperature has become a serious problem. This paper focuses on the thermodynamic characterization of sodium carbonate (Na2CO3) corrosion of six refractories by FactSage modelling in combination with X-ray diffraction (XRD). Three of the refractories are oxides (Fe2O3, Al2O3, and Cr2O3), and the other three are synthetics spinels (magnesium chromium, MgO·Cr2O3; magnesioferrite, MgO·Fe2O3; and, magnesium aluminium, MgO·Al2O3). First, thermodynamic simulations were carried out with the FactSage thermodynamics model using the reaction package to predict the direction of the Na2CO3 corrosion reaction in terms of the Gibbs free energy. Then, the reactions between the six refractories and Na2CO3 were conducted through a series of refractories/Na2CO3 reaction tests. The XRD analytical method was used to describe and understand the chemistry and interpret mineral matter transformation. The products of the tests were also determined by X-ray diffraction and the experimental observations were compared with the results of the thermodynamic simulations. Furthermore, the strength of sodium corrosion of the refractory materials was comprehensively discussed. The results show that MgO·Al2O3 has the best thermal stability and it is hard to corrode by Na2CO3, while the chrome-containing refractory reacts easily with Na2CO3 with a considerably high amount of corrosion product at a temperature of 600 °C. These experimental results are in agreement with the thermodynamic calculations.

No abstract

No abstract

No abstract

Incineration of high-content sodium salt organic waste liquid will corrode the refractory material in the incinerator, causing the refractory material to peel off and be damaged. A thermodynamics method was used to study the thermodynamic properties of three common sodium salts (NaCl, Na2CO3 and Na2SO4) on the corrosion of refractory materials (MgO·Cr2O3, MgO·Al2O3, Al2O3, MgO and Cr2O3). The results determined that MgO has the best corrosion resistance and is not corroded by the three sodium salts. On this basis, the thermodynamic corrosion experiments of NaCl corrosion of magnesium oxide at three temperatures of 600, 1000 and 1200 °C were carried out. Analysis of the corrosion product by X-ray diffraction (XRD) showed no corrosion product formation. Studies have shown that thermodynamic calculation can accurately predict the thermodynamic mechanism of alkali metal corrosion to refractory materials, and MgO is a good anti-alkali metal corrosion refractory material.

No abstract

No abstract