Hydrometallurgy

Extracting the elements that you need

Hydrometallurgy is the science of moving metal ions from a feed source (such as a mined ore body, concentrates, intermediate residues or recycled metallic feedstock including batteries) into aqueous solution. The valuable elements are recovered from solution as either intermediate or final saleable products produced using aqueous chemistry.

ProProcess personnel have vast experience in the hydrometallurgical field. We have experience in the research (from laboratory bench-scale scoping tests to pilot and demonstration facilities), operational and project sectors. Our engineers have an in-depth understanding of the chemistry and processes associated with base and precious metal refineries and the modularisation thereof.

Copper & Cobalt

The engineers at ProProcess have been at the forefront of setting the flowsheets for many of the copper and cobalt producers in the African Copper Belt. Our engineers have consulted on, lead and run the test work and pilot plant campaigns, performed the detailed design and commissioned the final plant for various copper and cobalt producers. We have supplied smaller individual unit operations, built and assembled pilot / demonstration plant skids and supplied modularised production plants for these operations. On cobalt we have extensive experience in producing intermediate cobalt salts for packaging and export, as well as the electrowinning of cobalt metal rounds and the subsequent treatment of the electrowon metal. The list of projects in this field which we have been instrumental in is extensive.

Gold

Gold processing plants readily lend themselves to a modular design approach because of the scale. On these plants it is desired to minimise gold lock-up within the process, and therefore these operations are far smaller than base metal refineries. ProProcess has experience in conventional and novel methods of processing gold. We have knowledge in: Cyanide Leach, Bacterial Leach, CIP, RIP, elution, reductive precipitation, EW.

Nickel

The extraction of nickel by hydrometallurgical means has seen a lot of development is the last few decades, particularly for laterite deposits. High-Pressure Acid Leach (HPAL) has gained traction as the preferred method to recover nickel from these difficult ores. ProProcess engineers have contributed to many of these new projects across the globe, and have been involved in the piloting of alternative processes. Nickel is also one of the base metals associated with PGM’s, and ProProcess’ s experience in the PGM industry has contributed to our experience in the purification and production of this metal, including electrowinning and hydrogen reduction.

Platinum

In 2020 it was reported that South Africa owns 91% of the worldwide platinum metal reserves (More info). The ProProcess engineers have been involved in numerous projects related to this PGM. The extraction and refining of PGM’s is a complex process which after mining includes flotation, smelting, base metal removal and finally separation of the various PGM’s into refined products. ProProcess engineers have experience in each of these steps and their respective unit operations, having done work at all of the top three platinum producers in South Africa. This is valuable and unique experience which is rare to find under one roof.

Manganese

South Africa also has vast resources of manganese, accounting for approximately 75% of the world’s identified manganese resources. Whilst the bulk of the manganese mined in South Africa is exported as lump ore or sintered ore, Electrolytic Manganese Metal (EMM) and Electrolytic Manganese Dioxide (EMD) are also produced. The production of EMM and EMD is ‘difficult’ and the associated process technologies are complex. The processes however include typical hydrometallurgical unit operations such as leaching, precipitation and electrowinning. ProProcess engineers have worked on conventional and novel processes for the production of EMM and EMD.