CSA Global congratulates first author, Principal Consultant, 1Maxim Seredkin, and authors 2Mikhail Savenya, 2Sergey Sukleta, 3Baurzhan Duisebayev on their recently accepted technical paper: ‘ISR – Emerging Technology for the Extraction of Nickel and Cobalt from Laterite Deposits.’
Dr Seredkin will present at ALTA 2020 between 7-14 November in Perth, Western Australia.
In-situ recovery (ISR) transfers hydrometallurgical processing of mineralised bodies to the subsurface to directly obtain solutions of commodities. As a result, there is little surface disturbance. For ISR to be successful, however, deposits need to be permeable. Furthermore, commodities need to be readily amenable to dissolution by leaching solutions over a reasonable period, with an acceptable consumption of leaching reagents.
Modern processing of nickel-cobalt ores generally involves pyrometallurgical / smelting and hydrometallurgical methods. Hydrometallurgical methods include AAL, PAL, HPAL and heap leaching technologies. All these methods are not economical; however, for deposits in the Urals and Kazakhstan. Nickel pyrometallurgical plants of the Urals are currently closed, and AAL, PAL and HPAL test work did not demonstrate viable economic parameters.
The Ural-Kazakhstan province hosts Mesozoic nickel-cobalt laterite deposits with Mineral Resources containing 0.2 to 3 Mt of nickel metal. The deposits occur within zones of ultramafic massifs of various ages and genesis. These deposits were silicified in Cenozoic time under cover of young sediments and are mainly represented by silicate mineralisation with quite low nickel and cobalt grades: Ni 0.3–1.3%, Co 300–500 ppm.
ISR has never been used for nickel-cobalt laterite deposits at the industrial scale. Successful laboratory and field pilot ISR tests have been completed in the past years however at several Urals deposits including Tochilnogorskoe (Lipovskaya group), Kungurskoye and Rogozhinskoe (Cheremshanskaya group), and Ekibastuz-Shiderty (Seredkin et al., 2016; Seredkin et al., 2019).
The most successful and complete ISR test was completed at the Ekibastuz-Shiderty deposit where sulphurous acid was used as the leaching agent. The nickel grade in pregnant solutions (PS) reached 120 mg/l and nickel was extracted in the form of nickel cathode. Nickel grades in PS in laboratory column tests reached 500–2,000 mg/l. The liquid to solid ratio is 12–15. These values are comparable with heap leaching on the Murrin-Murrin project (ALTA, 2009).
Hydrogeological conditions are quite favourable. Permeability is 0.1–0.3 m/day and higher in fragile and fault zones, comparable with uranium deposits in Wyoming. The ISR process will be applied above and below the water table with a collection of PS from the water table in fractured serpentinite.
Clean TeQ (Fairfield et al., 2018) has developed a process for the treatment of Ni-Co PS using a complex hydrometallurgical method (a combination of IX, SX and neutralisation of pregnant solutions after HPAL). This method is applicable for Ni-Co deposits in the Urals and Kazakhstan with some improvements for the treatment of PS after ISR.
CSA Global prepared an ISR process based on a combination of available modern technologies to support the Scoping Study for the Ekibastuz-Shiderty in 2019. This technology is potentially amenable to other deposits in the Urals and Kazakhstan and maybe even more favourable for laterite deposits in tropical zones (such as Indonesia).
About the Author
Dr Seredkin has more than 18 years’ experience in exploration, mining production and resource estimation. He has experience in a range of commodities and reporting codes (including JORC and NI43-101). Maxim is particularly sought after in industry and academia for his expertise in uranium, he has in-depth experience across a range of geological settings and deposit types. He has specialist skills in the application of in-situ recovery for uranium extraction based on 5 years of direct operational experience. In addition to uranium expertise, Maxim has experience in bauxite, rare earths and iron ore. Maxim has a strong scientific background, with research experience in ore genesis, petrology and the mineralisation of carbonatite, alkaline and ultramafic complexes, in hydrothermal-metasomatic gold and tungsten deposits.
1CSA Global Pty Ltd, Australia
2UGTC Ltd, Russian Federation
3JV Kazcobalt, Republic of Kazakhstan