Cobalt Blue Holdings (ASX:COB) completed a scoping study for its Halls Creek copper-zinc project in Western Australia, which showed a 10-and-a-half-year mine life, according to a June 6 filing with the Australian bourse.

The project in which the company has a 51% stake, is under a joint venture agreement with Koongie Park, a unit of AuKing Mining (ASX:AKN) requires an initial capital investment of around AU$73 million and up to AU$67million in working capital, the filing said.

The staged plan for the project includes one year of construction, five years of open-pit mining at the Onedin deposit, and four and a half years of underground mining at the Sandiego deposit, the company added.

Onedin is expected to produce up to 5,000 tonnes per annum of copper and 15,000 tonnes of zinc sulphate monohydrate, while Sandiego will yield copper and zinc concentrates averaging 7,300 tonnes and 13,300 tonnes annually, respectively, the company said.