The CONI Process – Pilot Plant for the Recovery of Copper, Cobalt and Nickel

This article presents the CONI process implemented at the pilot-plant scale by the Łukasiewicz Research Network – Institute of Non-Ferrous Metals (Łukasiewicz–IMN), a partner in the METALLICO project.

The CONI process focuses on the recovery of valuable metals such as copper (Cu), cobalt (Co), and nickel (Ni) from waste iron-arsenic (Fe-As) alloy generated during the pyrometallurgical processing of lead (Pb). The main objective of the CONI process is to convert metallurgical waste into valuable secondary raw materials – copper(II) carbonate concentrate and cobalt-nickel carbonate concentrate – that can be reused in industrial applications, particularly in the battery materials sector. In response to the growing demand for metals used in modern technologies such as energy storage and electromobility, this process supports the principles of the circular economy. It also contributes to strengthening Europe’s raw material independence.

The CONI process consists of the following unit operations:

-            crushing of the Fe-As alloy from the Pb pyrometallurgical process,

-            leaching of the Fe-As alloy,

-            precipitation of Fe and As in the form of scorodite (FeAsO₄·2H₂O),

-            removal of the remaining amount of Fe and As in the form of iron concentrate,

-            precipitation of Cu in the form of copper(II) carbonate concentrate (>30% Cu),

-            precipitation of Co and Ni in the form of cobalt-nickel carbonate concentrate (>20% Co+Ni).

Currently, the final stages of validation and optimization of the parameters of the individual unit operations are being carried out, based on conditions previously established at the laboratory scale. The leaching of the Fe-As alloy, precipitation of iron and arsenic in the form of scorodite, and removal of their remaining iron and arsenic contents are conducted in a newly installed reactor equipped with a mechanical stirrer and a cooling system (reflux condenser). The reactor is thermally insulated with mineral wool, which ensures stable process operation and maintains the required operating conditions. The precipitation of copper(II) carbonate concentrate and cobalt-nickel carbonate concentrate is carried out in reactors that are part of the existing equipment at Łukasiewicz-IMN.

Reactor equipped with a stirrer and cooling system (a reflux condenser).

Pilot-scale tests conducted to date have indicated the need for further optimization of process parameters, particularly in the stages of iron and arsenic precipitation as scorodite and the removal of their remaining iron and arsenic content in the form of iron concentrate. Optimization efforts are focused on improving the quality of the obtained precipitates and reducing the co-precipitation of copper in the sludge.

The pilot-scale operation results in the production of two CONI process products: a copper(II) carbonate concentrate (containing between 30.3 and 47.9 wt% Cu) and a cobalt–nickel carbonate concentrate (containing between 19.1 and 21.2 wt% Co and between 11.4 and 12.4 wt% Ni). The obtained materials exhibit high application potential, particularly for use in the production of cathode materials for batteries.

Copper(II) carbonate concentrate and cobalt-nickel carbonate concentrate.