Adastra Minerals has resumed talks with Congo's state mining company Gecamines to bring the Kipushi zinc and copper mine near the Zambian border back into production after 11 years of 'care and maintenance', in partnership with the local Kumba group. Headed by UK finance and investment man Tim Read, Adastra cites a measured and indicated resource there of 16.9m tonnes at 16.7% zinc and 2.2% copper. Kumba paid £2m for a half share and Read reckons it will cost £27.5m to extract 100,000 tonnes of zinc concentrate. Adastra, whose losses trebled to £1.8m in the six months to April, is also looking at gem targets in the Cuango flood plain of Angola but its key project is its 82.5%-owned Kolwezi tailings deposit in southern Congo, with an estimated resource nearly 113 million tonnes at 1.49% copper and 0.32% cobalt. With funding from the IFC (World Bank) and IDC (South Africa), Adastra says it could cost £166m to bring it into production in 2007, with an initial 30,000 tonnes of copper and 5,000 tonnes of copper a year - which could later be doubled - and achieve cash margins of more than 65% at assumed prices well below today's market levels. Read is in the Far East negotiating potential cobalt off-take deals. The shares have halved since April, but could reward a strong-nerved long-term punt.