Sulphur dioxide leaching of uranium containing material

Claim 1

A PROCESS FOR EXTRACTING URANIUM FROM URANIUM CONTAINING MATERIAL AT LEAST PART OF THE URANIUM OF WHICH IS TETRAVALENT COMPRISING THE STEPS OF COMMINUTING SAID MATERIAL, MAGNETICALLY SEPARATING METALLIC IRON PRODUCED DURING SAID COMMINUTING FROM SAID MATERIAL, LEACHING SAID MATERIAL WITH AN AQUEOUS SOLUTION CONTAINING SULPHUR DIOXIDE AND WITH AERATION TO AN EXTENT SUFFICIENT TO FORM A PROPORTION OF OXY-SULPHUR ACIDS TO GIVE A PH OF ABOUT 1 TO 2 BUT INSUFFICIENT TO GIVE EXCESSIVE REMOVAL OF SULPHUR DIOXIDE GAS AND CONTAINING A SUBSTANCE SELECTED FROM THE GROUP CONSISTING OF SOLUBLE FERRIC IRON IN AN AMOUNT OF 1 TO 2 GRAMS OF IRON TO A LITRE OF SOLUTION AND MANGANESE IN AN AMOUNT OF 0.5 TO 1 GRAM OF MANGANESE TO A LITRE OF SOLUTION AND MIXTURES THEREOF TO PROVIDE A LEACH SOLUTION, ADJUSTING THE PH OF THE LEACH SOLUTION TO ABOUT 1.25 AND PRECIPITATING URANIUM FROM SAID SOLUTION BY ADDING METALLIC IRON POWDER IN THE PRESENCE OF A PRECIPITANT SELECTED FROM THE GROUP CONSISTING OF SOLUBLE PHOSPHATES, ARSENATES AND FLUORIDES AND MIXTURES THEREOF.