Effect of basicity on the flow and crystallization behavior of synthetic nickel–iron alloy residue

Abstract

The new technology of mineral wool production with Nickel–Iron alloy waste residue has excellent prospect of development and application. The viscosity and crystallization behavior of Nickel–Iron alloy waste residue significantly influence the production process of the mineral wool. In current work, the influences of basicity on the viscosity and crystallization for four Nickel–Iron alloy waste residues have been investigated by confocal scanning laser microscope and viscometer, respectively. The crystals morphologies are characterized by field scanning electron microscope, and the compositions are analyzed by energy dispersive spectroscopy. According to the results, it is obvious that the experimental slag crystallization behaviors are consistent with crystallization kinetic model (Johnson-Mehl-Avrami equation). The crystallization rate, the crystal size, and the crystallization ability of Nickel–Iron alloy waste residue increases with increasing the slag basicity from 0.03 to 0.53. The main crystalline product is protopyroxene for No. 1 and No. 2 slags, and olivine for No. 3 and No. 4 slags. However, the viscosity of Nickel–Iron alloy waste residue decreases with the increase of basicity. The precipitation process of crystal has great influence on the viscosity of slag, and the influence degree of different crystal types is different. When the crystals in the slag grow up to a certain extent, the viscosity of the slag will increase dramatically.