Nickel, the dominant material of Nickel-based battery, is extracted from nickel laterite or nickel sulfide. World nickel resource consist of 72% nickel laterite and 28% nickel sulfide. However, the less nickel sulfide stock is more produced than the nickel laterite due to lower processing cost. But to fulfill nickel increasing needs, nickel laterite must be utilized.
Nickel laterite consist of Nickel, cobalt, iron, and Magnesium oxide. The depth of mining affects the amount of the elements. For instance, in the depth around 10 -15 meters, limonite can be mined which have 0,8 – 1,5% nickel content but deeper in around 15 – 20 meters, saprolite can be found which have 1.5 – 3% nickel content. Saprolite also has higher content of magnesium oxide and less cobalt than limonite.
The limonite and saprolite are then processed to refine the targeted elements. There are two well-known processes called pyrometallurgy and hydrometallurgy. Pyrometallurgy uses thermal treatment to enable valuable material recovery, while hydrometallurgy uses acid. The expected product of these process is in the form of nickel matte or MHP (mixed Ni-Co hydrate precipitate). Then, the MHP is purified to form nickel sulphate and cobalt sulphate.
|Date||:||12 October 2020|