Direct preparation of low Ni-Cr alloy cast iron from red mud and laterite nickel ore

摘要

Based on the chemical composition requirements and enhancing the utilization value of the products, this work put forward a direct preparation method for low Ni-Cr alloy cast iron from red mud and laterite nickel ore by high-temperature carbothermal reduction smelting and refining. X-ray fluorescence (XRF), optical emission spectrometer (OES), scanning electron microscopy (SEM) attached with energy dispersive spectroscopy (EDS) analysis, hardness and polarization tests were used in the characterization process. The results show that low Ni-Cr alloy cast irons contain 1.50-2.00 wt.% Ni and 0.70-0.80 wt.% Cr have been prepared as the mass ratios of red mud to laterite nickel ore vary from 80: 20 to 70: 30, in which the recovery were 93.70% for Fe and 99.83% for Ni, respectively. The alloy cast iron was consisted of ledeburite and cementite matrix with evenly distributed Ni and Cr elements and block and flake graphite precipitated phase. With the increasing of Ni and Cr contents, the hardness and corrosion resistance of the alloy cast irons improved. (C) 2016 Elsevier Ltd. All rights reserved.