Kerogen—Mineral bonding and beneficiation studies with a carbonate oil shale,using carbonic acid attack and a novel explosive disintegration technique

CO₂ and water under pressures up to 5.2 MPa and temperatures up to 200°C have been used to attack the mineral matrix of a carbonate oil shale from Julia Creek, Australia. In most experiments the chemical attack was coupled with an explosive depressurisation process (Siropulper) which produced considerable comminution of the shale. Changes in kerogen—mineral bonding and potential for beneficiation were assessed by float—sink separations. No kerogen was liberated, and only small amounts of kerogen-enriched material were freed by these treatments, even where all the carbonate minerals had been dissolved. Carbonate minerals do not appear to play any special role in bonding kerogen in this shale, and these disintegration techniques show no promise for gravity beneficiation processes with it.