Laterite nickel ore adopts HPAL high-pressure acid leaching smelting+extraction of nickel and cobalt, with recovery rates of 96% and 94%

Release time:

2023-08-04

Source:

In the era of energy transformation, nickel, as the third metal under electrification, will experience explosive growth in power battery nickel with the explosion of terminal demand for new energy vehicles and the gradual promotion of high nickel content. About 60% of global land nickel resources exist in the form of laterite nickel ore. With the development of more and more laterite nickel ore projects, the nature of laterite nickel ore resources is also increasingly understood. Currently, the smelting process of laterite nickel ore includes pyrometallurgy There are two main directions for wet method, generally fire method is suitable for silicon magnesium type nickel ore with relatively high nickel content, and wet method is suitable for brown iron type nickel ore with relatively low nickel content.

1、 Why HPAL high-pressure acid leaching is used in the wet smelting of laterite nickel ore

The wet smelting process of laterite nickel ore mainly includes three types: reduction roasting ammonia leaching (Caron process), high-pressure acid leaching (HPAL), and atmospheric acid leaching (AL). The three wet processes are suitable for laterite nickel ores with different MgO contents. Due to the unnecessary consumption of acid in the reaction caused by MgO, which increases costs, HPAL is generally suitable for treating brown iron type ores with Mg content less than 5%.

Although HPAL has strict reaction conditions, strict equipment requirements, and a relatively high level of capital expenditure, due to its obvious advantages in nickel cobalt recovery rate and relatively small energy consumption emissions, it is the current and future mainstream route and development direction of wet processes.

2、 What is high-pressure acid leaching? What are the advantages of the high-pressure acid leaching process?

The high-pressure acid leaching process, also known as the HPAL process, generally uses dilute sulfuric acid as the leaching solution. In a high-temperature and high-pressure environment of 240-270 ℃ and 4-5MPa (about 40-50 times the standard atmospheric pressure), the process parameters are adjusted to allow nickel and cobalt to enter the leaching solution, while most of the iron and silicon enter the slag. After subsequent neutralization and impurity removal precipitation, MHP (nickel cobalt hydroxide) or MSP (nickel cobalt sulfide) are obtained.

The core of the HPAL process is to ensure the full leaching of nickel and cobalt in a high-temperature and high-pressure reaction environment under the control of fine parameters. The entire process is divided into four parts: feed preparation, high-pressure acid leaching, neutralizer CCD countercurrent washing, and precipitation.

After years of development, the HPAL process has made significant improvements in process design. Currently, the recovery rates of nickel and cobalt in the entire process can reach nearly 96% and 94%. As the manufacturing process of large high-pressure reactors gradually matures and the level of equipment improves, the advantages of high-pressure acid leaching process will become increasingly apparent. After several generations of development, there will be significant improvements in capital expenditure, construction cycle, and climbing cycle. The HPAL process is the main direction for the future development of laterite nickel ore hydrometallurgical processes.

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Extracting scandium from laterite nickel ore using extraction method with low investment cost

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Extracting scandium from laterite nickel ore using extraction method with low investment cost