The problem of recovery of cobalt products from poorly oxidised
nickel ores (Kempirsaisk deposit) and pyrite concentrates with a
low content of cobalt (Sokolovsk-Sarbaisky deposit) has not been
solved to the present time in Kazakstan. The balance reserves of
nickel ore of the Kempirsaisky deposit make up more than 35
million tons with a nickel content of 1.13 per cent and cobalt
content of 0.05 per cent; besides there are 110 millions tons of
out-balance ores (Anon, 1995). In a tailing dump of Sokolovsk-Sarbaisk Mining and
Productional Association more than 320 million tons of tailings
of wet magnetic separation have accumulated, which contain 7.2
per cent of sulphur, 0.022 per cent of cobalt, 0.012 per cent of
nickel, 0.094 per cent of copper, 0.079 per cent of zinc, 16.45 per
cent of iron, and from which a high quality pyrite concentrate car)
he separated through flotation, containing 48 - 50 per cent of
sulphur, 44.15 per cent of iron, 0.141 per cent of cobalt, 0.07 per
cent of nickel, and 0.10 per cent of copper. The well-known technological flow charts for cobalt and nickel
recovery from the tailings of sulphide-magnetite ores dressing (to
give pyrite concentrate) and from oxidised nickel ores, are not
profitable at the existing prices for metals, but are not worthless
and require significant capital investments for the realisation of
their value. The flow chart `sulphate roasting - leaching - solution processing' is used widely for combined processing of
cobalt-containing pyrite ores and concentrates.