Method of microwave selective reduction roasting-dilute acid leaching nickel oxide ore

Abstract

The invention relates to a microwave selective reduction roasting-dilute acid method for lixiviating nickel oxide ore. The nickel oxide ore, such as limonite type lateritic ore containing nickel, is mixed with a reducing agent containing carbon, such as nano carbon powder, active carbon, xylanthrax, soft coal and / or anthracitic coal, and then heated under the microwave irradiation of 2450MHz or 916MHz. As material containing carbon has excellent microwave absorption capability, microwave is used for rapidly heating the material so as to realize rapid warming of reactants, quicken the reduction of valuable elements in the ore, such as nickel and cobalt and control the reduction degree of iron so as to realize the selective reduction roasting of the ore. Selective lixiviating of nickel and cobalt is carried out on reduzate after roasting in the dilute acid solution so as to realize the effective extraction of nickel and cobalt. The method of the invention has short roasting time, low consumption of reducing agent and low energy consumption. The consumption of reagents is low during lixiviating and lixiviated residue is suitable for being used for iron making as raw material so that no damage to environment occurs.

Description

technical field [0001] The invention belongs to the field of mineral extraction metallurgy. Specifically, the invention relates to a microwave selective reduction roasting-dilute acid leaching nickel oxide ore method. Background technique [0002] Nickel is a versatile metal, often used in the production of stainless steel, superalloys, electroplating, catalysts and magnets. [0003] Although nickel exists in many kinds of minerals, there are currently two kinds of mineral raw materials for large-scale smelting and extraction of nickel, sulfide ore and oxide ore. Sulphide ore can generally be obtained by beneficiation of nickel concentrate. However, nickel-containing oxide ores such as laterite ores, due to the different origins of the minerals, nickel and cobalt exist in the minerals in the form of lattice replacement, are highly dispersed, and cannot be enriched by direct beneficiation methods, only direct chemical treatment . [0004] Nickel-containing oxide ores such ...

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Problems solved by technology

Patents GB 2435649A and US4906290A also use the method of microwave heating the mixture of minerals and carbon powder, but both adopt the method of reducing all iron-containing minerals, the consumption of reducing agent is large, and the energy consumption is high. This process is used to treat low-grade When mining, due to the large amount of slag in the process of high-temperature smelting reduction, it is easy to exceed a large amount of entrainment loss of valuable metals, and the metal yield is low

[0013] The above-mentioned methods all have disadvantages such as higher acid consumption, leaching slag harmful to the environment or low recovery rate of nickel-cobalt metal. A New Method of Treating Ni-containing Oxide Ore by Sexual Reduction Roasting-Dilute Acid Leaching