환원 조건에서 석탄 슬래그의 Tcv 예측

Abstract

slag viscosity is an important factor determining the operation temperature of entrained flow type ofgasifiers. The temperature of critical viscosity, Tcv, for 5 crystalline slags was predicted by empirical models and Fact-Sage equilibrium calculations, and the validity of each method was tested. Two empirical models were employed: oneusing Th from the ash fusion test, and the other using the concentrations of 5 major components. The first model usingTh over-predicted Tcv by 20~100oC, while the model based on the slag composition under-predicted Tcv by 80~120oC.In the equlibrium calculations, Tcv was obtained from the liquidus temperature. When the 4-major component concen-trations were used in the calculation, the predicted temperatures were higher than the observed. The liquidus tempera-ture was very sensitive to the concentrations of minor components, and the addition of MgO and Na2liquidus temperature. The results with 4 major and 3 minor components most closely described experimentally observedTcv. In the case that a chromia refractory was used, it was shown that Cr2O3 concentration in the slag also needs to beincluded for more acurate prediction of Tcv.