The Guide to Nickel Processing Methods

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The beneficiation process of nickel ore is the process of extracting nickel metal from nickel ore, which varies depending on the type and composition of the ore. According to the nature of the ore, nickel ore can be roughly divided into nickel sulfide ore and nickel oxide ore, which have different beneficiation processes. This article will introduce the nickel ore beneficiation process and key processes in detail.

Nickel sulfide ore is one of the most common nickel ores in the world, usually coexisting with copper, cobalt and other associated metal ores, has a high economic value. The beneficiation process of nickel sulfide ore mainly adopts flotation method, which is suitable for the separation of fine-grained nickel sulfide ore. The specific process flow is as follows:

1. Crushing and screening

The raw ore is preliminarily crushed by jaw crusher or cone crusher, and the crushed ore is screened to get the particle size suitable for grinding. The ore with larger particle size will return to the crushing process and continue to be crushed to a suitable size.

2. Grinding 

After crushing, the ore enters the ball mill for grinding, so that the ore size reaches the fineness required for flotation. Generally, the ore needs to be ground until 80% passes through a 200 mesh sieve to ensure that the minerals are fully dissociated.

3. Flotation 

The ore slurry after grinding enters the flotation machine through pharmaceutical adjustment. Commonly used agents in the flotation process include trapping agents (e.g., yellows, butyl yellows) and frothing agents (e.g., turpentine oil). The trapping agent promotes the separation of nickel minerals from other minerals, while the frothing agent helps to generate air bubbles that attach to nickel ore particles and float them to the surface of the slurry, thus separating them from the vein minerals.

4. Concentrate Dewatering 

The nickel concentrate obtained after flotation usually contains a large amount of water, which needs to be reduced by thickening and filtration. Commonly used equipment includes thickeners and filters, resulting in a lower moisture nickel concentrate for subsequent smelting.

5. Tailings treatment 

The tailings after flotation will be properly treated, generally the tailings contain a small amount of valuable metals, after recovery treatment, the wastewater will be discharged or recycled after treatment to meet the standards.

Oxidized nickel ore ore properties are more complex, usually accompanied by a large number of silicon, magnesium and other impurities, and nickel minerals and veinstone dissociation is more difficult. Because the flotation method is not suitable for the treatment of nickel oxide ore, nickel oxide ore beneficiation process is mainly used for pyrometallurgical smelting and hydrometallurgical smelting. 

Pyrometallurgical smelting is suitable for high nickel grade ores, while hydrometallurgical smelting is suitable for low grade ores.

1. Ore nature analysis 

Before designing the beneficiation process, the composition and nature of the ore should be analyzed in detail. Different ore types and nickel endowment state will affect the selection of beneficiation process. Especially oxidized nickel ores, which are often accompanied by more impurities such as magnesium and silicon, require special design of the treatment process.

2. Environmental protection measures 

The tailings, wastewater and exhaust gas generated in the nickel ore beneficiation process have a certain impact on the environment. Therefore, the beneficiation plant needs to take necessary environmental protection measures, such as tailings recovery and treatment, wastewater recycling and exhaust gas emissions to meet the standards, in order to reduce the pollution of the environment.

3. Control of energy consumption 

Nickel ore beneficiation, especially the pyrometallurgical smelting process is more energy-consuming, so in the process design should try to choose energy-saving equipment and optimize the production process, in order to reduce energy consumption and reduce production costs.

Nickel ore beneficiation process varies according to the type of ore, nickel sulfide ore usually adopts flotation method, while nickel oxide ore is mainly smelted by pyrometallurgy or wet smelting. In actual operation, it is necessary to choose the appropriate process according to the nature of the ore and production conditions, and pay attention to environmental protection and energy saving measures. With the continuous progress of beneficiation technology, the nickel ore beneficiation process will develop in the direction of more efficient and environmentally friendly, providing better technical support for the extraction and utilization of nickel metal.