PREPARATION PROCESS OF THE TRIVALENT CHROME COMPOUNDS WHICH ARE INSOLUBLE IN WATER AND WHICH ARE MADE FROM RESIDUAL PRODUCTS FROM THE CHROME ORES-WORKING

摘要

The present invention concerns a new process and the relative plant for reducing hexavalent chromium contained in the resultant earth after the production of chromium, in order to obtain the transformation from water-soluble compounds into insoluble compounds, the process comprising the phases of mixing the said residual products with one or more reducing agents and of indirectly heating the said mixture substantially without the presence of oxygen.