The diamond miner decided to offload those units to focus on its Tongo-Tonguma project in Sierra Leone, which has the potential to generate earnings of $45 million a year.
Chalkstone was born out of counter-insurgency tactics used by troops in Afghanistan, but its unique methodology is now being used by miners, which can map-out power structures and counter the potentially crippling risk of strikes and political opposition.
The Canadian diamond miner now expects to produce between 265,000 carats and 285,000 carats, compared with the previously targeted 290,000-310,000 carats.
Authorities seek to settle differences with the Canadian miner over Skouries, one of the gold projects the firm is currently developing in northern Greece.
Miner said country offers more favourable conditions to start new projects than Chile, where Antofagasta has majority stakes in four copper mines and has just opened a new one — Antucoya.