Aureus Mining has temporarily suspended operations at the New Liberty gold mine in Liberia due to a cyanide leak caused by problems with the process plant's detoxification circuit.
The company said that the circuit stopped operating according to design specifications, which resulted in higher concentrations of cyanide WAD (weak acid dissociated cyanide) in the process effluent.
Aureus has since been operating with process water in a closed circuit.
The company is performing repair work to resolve the issues in the circuit and manage future water discharge from the tailings storage facility (TSF).
The discharge took place within the mining area, with no adverse impacts reported in residential areas 5km away.
Further investigations are being carried out to determine the cause of the leak.
The company engaged SRK Consulting (UK) to assist with evaluation of the adjustments that are needed to the detoxification circuit's waste neutralisation section.
Aureus and its 100%-owned subsidiary Bea Mountain Mining (BMMC) are working with the Environmental Protection Agency of Liberia (EPA) and the Ministry of Lands, Mines and Energy (MLME) and local downstream communities to avoid any environmental risks.
The EPA will review the proposed remediation work. Prior to restarting gold processing operations at the mine, Aureus must obtain approval from the EPA and MLME.
The company is continuing mining operations at New Liberty to build up ore stockpiles and undertaking waste stripping.