CO2 mineralization and concurrent utilization for nickel conversion from nickel silicates to nickel sulfides

Global warming due to increased greenhouse CO2 gas emissions and increasing nickel demand are two issues that are challenging the sustainable development of the modern world. These challenges can be met in one process whereby CO2 mineralization can be utilized for simultaneous mineral carbonation to stabilize CO2 gas and concurrent nickel sulfidization. The newly formed nickel sulfide may be recovered by conventional means to enhance industrial nickel supply. Mineral carbonation provides the pre-condition for nickel sulfidization to release nickel into aqueous solution from the crystal structure of olivine as a secondary nickel resource. The released nickel ions can be converted to nickel sulfide for further recovery while other bivalent metal ions such as Mg2+ can concurrently react with CO2 to form stable carbonates. The continuous supply of sulfide ions and CO2 is important to achieve selective nickel conversion and mineral carbonation. A mixed gas containing 5% H2S - 95% CO2 can accelerate mineral carbonation and form nickel sulfide.

Automated summary

The study proposes a method to address the dual challenges of global warming and nickel supply by utilizing CO2 mineralization for simultaneous mineral carbonation and nickel sulfidization. By releasing nickel ions, converting them into nickel sulfide, and reacting with other metal ions, stable carbonates are formed. Continuous supply of sulfide ions and CO2 is crucial for achieving selective nickel conversion and mineral carbonation.