关键词: 红土镍矿, 转底炉, 还原, 磨矿, 弱磁选

Abstract: The low-iron， low-nickel and high-magnesium nickel laterite ore was investigated， in which contains 17.68% iron， 1.62 nickel and 19.06% MgO， respectively. Nickel mainly replaces iron and magnesium and exists in the form of isomorphism in iron oxides and silicate minerals， accounting for 39.65% and 54.72%. To determine the high-efficiency development utilization process， small-scale basic tests were conducted to obtain the parameters of the reduction-roasting and grinding-separation process and pilot-scale test was carried out on a rotary hearth furnace with a pitch diameter of 8 m. The results showed that the sample was treated by coal-based direct reduction， water quenching and two-stage grinding and low-intensity magnetic separation. The mass ratio of laterite nickel ore， limestone and TN was 100∶10∶3， mole ratio of C to O was 1.2 (anthracite) ， the reduction time was lasted 40 min in the temporary of 1 280 ℃. The water-quenched calciation products at first stage grinding fineness of -0.074 mm accounting for 83.31%， and the magnetic field intensity of first stage low-intensity magnetic separation was 190.98 kA/m， second stage grinding fineness of -0.074 mm accounting for 97.43%， and the magnetic field intensity of second stage low-intensity magnetic separation was 127.32 kA/m. Under the optimal conditions， ferronickel powder product which contains 5.63% nickel and 60.39% iron with recovery of 80.83% and 75.14% can be obtained. The pilot product of the rotary hearth furnace was ground and separated. The obtained ferronickel powder product contains 5.26% nickel and 59.20% iron， while the recovery of nickel and iron were 80.84% and 74.98%， respectively. The research results can be used as the basis for engineering， and can also provide a technical reference for the efficient development and utilization of the same type of laterite nickel ore resources.

Key words: Nickel laterite ore, rotary hearth furnace, direct reduction, grinding, low-intensity magnetic separation