Low - grade Laterite Nickel Ore Beneficiation: Unlocking New Potential of Nickel Resources

Low - grade laterite nickel ore usually has a high iron content and a low nickel grade. Traditional beneficiation methods are difficult to achieve effective enrichment. The high - pressure acid leaching (HPAL) process has emerged as the mainstream technology for processing such ores. In the HPAL process, the nickel - cobalt precipitation and enrichment technology is a core link, which directly affects product quality and production costs.

In the early days, the hydrogen sulfide method and the magnesium oxide method were commonly used nickel - cobalt precipitation technologies. Although the hydrogen sulfide method has good selectivity for nickel and cobalt and high - purity products, the high toxicity of hydrogen sulfide brings serious safety and environmental hazards. Its preparation and storage systems are complex and have poor compatibility with the main process. The magnesium oxide method is highly safe and can produce products with good purity. However, the activity problem of magnesium oxide restricts its wide application. High - activity magnesium oxide is costly, and it is easy to lose its activity due to improper transportation and storage, resulting in an increase in the magnesium content of the product.

The Alkali Activation Controlling Precipitation (AACP) technology developed by China ENFI Engineering Corporation has brought new breakthroughs to the nickel - cobalt precipitation of low - grade laterite nickel ore. The AACP technology skillfully uses the in - situ base conversion of sodium hydroxide to reconstruct sodium hydroxide into magnesium hydroxide, maintaining a low introduction rate of hydroxide ions in the system, making the precipitation particles grow mainly through the growth mechanism and realizing secondary construction. Pre - seeding reforming and template - induced growth activate the seed crystals, creating favorable conditions for particle growth. The convergent system regulation establishes the logical relationship between phenomena and essence in the production process, which can quickly judge and solve problems in production and ensure stable product quality.

The AACP technology has been successfully applied in many projects. After the Ruimu Nickel - Cobalt Project in Papua New Guinea adopted the AACP technology, the product quality was significantly improved. The nickel content increased steadily from 36% at the initial stage to about 39%, the water content dropped below 61%, the amount of flocculant used was greatly reduced, and a large amount of transportation costs and fuel consumption were saved. The production capacity utilization rate far exceeded that of projects in the same period. The Ningbo Liqin Project and the Huayue Laterite Nickel Ore Hydrometallurgy Project also achieved high production after applying this technology. The products had high nickel content, low magnesium content, and low water content, bringing huge economic benefits to the enterprises.

In addition, China ENFI has also developed the High - Pressure Acid Leaching Process Equipment Engineering System (ENFIHPAL). Its unique process engineering leap - level simulation system and equipment coupling optimization system can predict problems in the initial stage of the project, optimize equipment design, shorten the project implementation cycle, and ensure the stable operation of the equipment system under complex conditions.

With the continuous development of the new energy industry, the demand for nickel will continue to grow. The progress of low - grade laterite nickel ore beneficiation technology, especially the application of the AACP technology, provides a strong guarantee for the efficient utilization of this rich resource. In the future, relevant technologies will continue to innovate, bringing broader development prospects for the nickel ore beneficiation industry.