| 摘要 |
A process is disclosed for incinerating tannery waste solids containing organic material and chromium which comprises burning at least one ton per day of said waste in the combustion zone of an industrial furnace at a low temperature, preferably between about 800 DEG F. and 1200 DEG F., to convert at least a portion of the organic material to gases and the chromium to ash, removing the gases from the combustion zone and subjecting them to further oxidation, and removing the ash from the furnace. The waste solids include sludge separated from liquid waste, leather scrap, or preferably both. By controlling temperature, waste composition, or both, the chromium in the ash can be obtained in either trivalent or hexavalent form. The hexavalent chromium can be extracted with solvent for reuse in the tanning process. Trivalent chromium, with or without carbon, can be recovered as chromic oxide in an improved stable form for landfill, storage or shipment to a reprocessing center.
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