Redbank says it has achieved its goal of extending the mine's planned life from five years to 10 years, having increased the copper resource through exploration. It released a development study on Tuesday, which revealed a total project capital cost of $54.8 million. Redbank reported last week it had only $1.33 million cash on hand after saying in December it could raise up to $US7.5 million ($A8.5 million) through the issue of convertible notes to US-based institutional investor La Jolla Cove Investors Inc.