Behavior of Slag in Ferromanganese and Silicomanganese Smelting Process

A review of studies by Safarian et al. and Kim show that the smelting reaction at equilibrium for ferromanganese and silicomanganese alloys is defined by the coupled reaction in the carbon-saturated condition $$ 2\underline{\text{Mn}} + \, \left( {{\text{SiO}}_{ 2} } \right) \, = { 2 }\left( {\text{MnO}} \right) \, + \underline{\text{Si}} $$ 2 Mn ̲ + SiO 2 = 2 MnO + Si ̲ . The behavior of slag at equilibrium is described by MnO and SiO2 as dependent variables and by non-reacting species, CaO, MgO, and Al2O3, as independent variables. Its characteristic behaviors are assessed in the pseudobinary system of MnO and SiO2 fixed by non-reacting components with analyses of ferromanganese and silicomanganese slag from one-month smelting operations. The behavior of fluid slag is defined by their melting temperature provided by phase equilibria of slag system. Liquidus of manganese slag systems by Kang et al., Zhao et al., and Roghani et al. is reconstructed in coordinates of MnO and SiO2 at fixed contents of CaO, MgO, and Al2O3. Conditions for fluid smelting slag are examined by referencing characteristic behaviors of smelting slag to liquidus of manganese slag systems to assess the effect of MgO and Al2O3. MgO facilitates fluid silicomanganese slag but would make ferromanganese slag viscous. Al2O3 makes silicomanganese slag fluid at Al2O3 content with 0.41 by weight ratio to SiO2. At higher contents of Al2O3, silicomanganese slag would be viscous with low MnO contents in slag. Al2O3 facilitates the development of fluid ferromanganese slag.

Phase relations of the Ce2Co17–Sm2Co17 pseudo-binary system

The phase relations in the Ce2Co17-Sm2Co17 system over the whole concentration range have been studied by means of Xray powder diffraction, differential thermal analysis and scanning electron microscopy equipped with energy dispersive Xray spectroscopy. The X-ray powder diffraction results reveal that all the alloys (Ce1-xSmx)2Co17 are similar to the end member of the investigated system, Sm2Co17. It is implied that continuous solid solutions are formed in this system. The lattice parameters and unit cell volumes of (Ce1-xSmx)2Co17 solid solutions increase linearly with x increasing from 0 to 1.0. The occurrence of the polymorphic transformation reaction α-(Ce, Sm)2Co17 = β-(Ce, Sm)2Co17 is confirmed in the Ce2Co17-Sm2Co17 system, but its transition temperature cannot be determined. The differential thermal analysis measurements show that both the decomposition temperature and the Curie temperature of the (Ce1-xSmx)2Co17 alloys increase gradually with increasing Sm content. Based on the X-ray powder diffraction results and differential thermal analysis data, the tentative vertical section of Ce2Co17-Sm2Co17 pseudobinary system has been constructed.