Fire process mainly includes nickel iron process and nickel sulfonium process. Wet process mainly includes reduction roasting - ammonia leaching, high pressure acid leaching and atmospheric acid leaching. Among them, the atmospheric acid leaching process has the advantages of less investment, less technical risk, easy to operate, wide application of minerals, higher yield, and become a very attractive process choice. But so far, atmospheric acid leaching technology has not realized large-scale industrial application, its main problem is that the acid consumption is large, the leaching solution is difficult to deal with. The nickel in laterite nickel ore mainly occurs in iron ore in the form of lattice substitution.

If the ordinary neutralizer is used to precipitate and remove iron, the precipitation amount is large, the filtration is difficult, and the entrainment loss of nickel/cobalt is large. If the extraction method is used to remove iron, the amount of extraction agent is large. Therefore, how to solve the problem of high acid consumption in atmospheric acid leaching process and separation of iron and nickel in the leaching solution is the main bottleneck for the industrialization of atmospheric acid leaching process. The national engineering laboratory of hydrometallurgical clean production technology, institute of process engineering, Chinese academy of sciences has developed a new hydrochloric acid leaching process for laterite nickel ore at atmospheric pressure. The new process not only realizes the efficient separation of nickel, cobalt and iron, but also realizes the regeneration cycle of hydrochloric acid. After further impurity removal, extraction separation and sulfuric acid transformation, the nickel and cobalt solutions obtained by the process were finally obtained and used for electrolysis in this study.