Nickel ore Beneficiation

Nickel ores mainly include sulfide copper-nickel mine and nickel oxide mine. The two ores have totally different beneficiation and processing methods.

Beneficiation of sulfide copper-nickel mine

Beneficiation of sulfide copper-nickel mines mainly includes flotation, with magnetic separation and gravity concentration as supplementaries. In the flotation of sulfide copper-nickel mines, we usually concentrate the sulfide copper-nickel mines with collector and blowing agent. In the flotation process, we must follow one principle, that is, avoid the presence of copper in the nickel concentrate, still less nickel in the copper concentrate. This is because we will lose much of nickel in the smelting of copper concentrate while in the smelting of nickel concentrate, we could recycle nearly all of the copper.

The flotation of copper-nickel mine includes the following four processes.

Preferential flotation or partially preferential flotation process: We adopt the process when the mine has much more copper than nickel to smelt the copper into copper concentrate. By the process, we could get copper concentrate with a low level of nickel.

Mixed flotation process: The process is used to separate mines that has more nickel than copper. The copper-nickel mix concentrate could be directly smelted into nickel matte.

Mixed-preferencial flotation process: The process carries out mixed flotation of copper and nickel, and then separate copper concentrate with few nickel and nickel concentrate with few copper from the mixture. We could get nickel matte after the smelting of the nickel concentrate, and then carry out another flotation of the nickel matte.

Mixed-preferential flotation altogether with recycling of nickel from the tailings: When nickel ores in the mines differ greatly from each other in flotability, we could further recycle nickel ores with low flotability from the trailings.

The beneficiation process consists of three-section closed circuit crushing, phase-based grinding, mix-separation flotation of copper-nickel mines, three-section dehydration of nickel concentrate, and two-section dehydration of copper concentrate.

Separation of nickel oxide ores

Before the separation of nickel oxide ores, we must get rid of low-weathered bedrocks that contain few nickel through crushing and screening process. As nickels in the nickel oxide ores are small and usually scattered in gangue minerals as isomorphism, we could only concentrate the ores through direct smelting instead of mechanical separation.

We get the concentration of nickel oxide ores through burning or wet process. The former process can be divided into sulfer smelting, nickel-iron method and ferrite method while the latter include reduction roasting- atmospheric ammonia leaching and high-pressure acid leaching.