Obiettivo RECOVERY OF ELEMENTAL SULPHUR AND METAL FROM PYRITES WITH LOW METAL CONTENT. THE RESEARCH INTENDS TO DEVELOP A PROCESS GETTING THE WHOLE SULPHUR CONTAINED IN A PYRITIC ORE AS ELEMENTAL SULPHUR AND RECOVERING ALL THE METAL VALUE (IRON, BASE METALS AND PRECIOUS METALS). SUCH A PROCESS WOULD MAKE IT POSSIBLE TO WORK PYRITIC ORES, THE GRADE OF WHICH IS TOO LOW FOR THE RECOVERY OF BASEMETALS ONLY TO BE ECOMOMICALLY ATTRACTIVE BUT IN WHICH THE TOTAL AMOUNT OF BASE METALS CORRESPONDS TO A SIGNIFICANT POTENTIAL OUTPUT. LOW GRADE BASE METAL ORES WITH PYRITIC GANGUE COMMONLY UNDERGO AN OXIDYING ROAST WITH PRODUCTION OF S02 (AND THEN SULPHURIC ACID). A PROPORTION OF SULPHUR IS SOMETIMES RECOVERED IN ELEMENTAL FORM. THE BASE METALS ARE THEN RECOVERED FROM THE CINDERS, MOST OFTEN THOUGH A CHLORIDIZING STEP AND HYDROMETALLURGICAL PROCESSING OF THE METAL CHLORIDES. THIS RECOVERY IS NECESSARY FOR THE CINDERS TO BE USABLE IN THE STEEL - MAKING INDUSTRY. SUCH PROCESSES ARE RATHER UNATTRACTIVE FROM AN ECONOMIC POINT OF VIEW. OTHER PROCESSES RECOVERING SULPHUR IN ELEMENTAL FORM HAVE BEEN DESCRIBED IN LITERATURE BUT THEY ARE NOT FULLY KNOWN AND NONE OF THEM UNTIL NOW HAS BEEN DEVELOPED EITHER AT INDUSTRIAL OR PILOT-PLANT SCALE. THE RECOVERY OF ELEMENTAL SULPHUR RATHER THAN SULPHURIC ACID WOULD MAKE IT POSSIBLE TO INTEREST A MUCH WIDER MARKET. NOWADAYS THE ELEMENTAL SULPHUR WORLD MARKET IS BALANCED, BUT IT WILL SHOW A DEFICIT AFTER 1985. EUROPE ALREADY IMPORTS SULPHUR (IN 1981, 5,9MT CONSUMED VERSUS 3,6 MT PRODUCED). THE EUROPEAN SULPHUR PRODUCTION, COMING MAINLY FROM THE GERMAN AND FRENCH NATURAL GAS FIELDS, IS GOING TO DECREASE FROM 1983 AND THE SHORTAGE IS GOING TO WORSEN BY MORE THAN 1 MT WITHIN THE FIVE NEXT YEARS. THE PRODUCTION OF ELEMENTAL SULPHUR FROM ORE DEPOSITS SUCH AS ROUEZ WOULD MEAN THAT THE NUMEROUS SULPHURIC ACID PLANTS IN THE EEC WHICH USE ELEMENTAL SULPHUR AS A RAW MATERIAL COULB CONTINUE TO BE SUPPLIED WITH EUROPEAN SULPHUR. AFTER AN EXTENSIVE LITERATURE SURVEY, THREE PARTIALLY ORIGINAL PROCESS SCHEMES HAVE BEEN SUGGESTED : A) IN THE FIRST ONE, THE ORE IS REACTED WITH GASEOUS CHLORINE TO PRODUCE ELEMENTAL SULPHUR AND METAL CHLORIDE. THE SULPHUR AND THE NON-FERROUS METAL CHLORIDE ARE CONDENSED FROM THE GASEOUS PHASE. B) IN THE SECOND ONE, PYRITE IS THERMALLY DECOMPOSED IN THE PRESENCE OF A CONTROLLED AMOUNT OF OXYGEN SO AS TO PRODUCE SO2 ANDPYRRHOTITE. THE PYRRHOTITE IS THEN LEACHED WITH HYDROCLORIC ACID, PRODUCING H2S. ELEMENTAL SULPHUR IS PRODUCED BY REACTING HS2 AND SO2. IRON IS RECOVERED FROM THE LEACHING SOLUTION AND NON-FERROUS METALS FROM THE LEACHING RESIDUE. C) IN THE THIRD PROCESS, PYRITE UNDERGOES A THERMAL TREATMENT UNDER A NEUTRAL ATMOSPHERE TO PRODUCE ELEMENTAL SULPHUR AND PYRRHOTITE. PYRRHOTITE IS THEN LEACHED UNDER PRESSURIZED OXIGEN TO GET ELEMENTAL, IRON OXIDE AND NON-FERROUS METAL SULFATEDS. Programma(i) PRE-RAWMAT 2C - Research and development programme (EEC) in the raw materials sector, 1982-1985 Argomento(i) Data not available Invito a presentare proposte Data not available Meccanismo di finanziamento Data not available Coordinatore Bureau de Recherches Géologiques et Minières (BRGM) Contributo UE Nessun dato Indirizzo Avenue de Concyr 45060 Orléans Francia Mostra sulla mappa Costo totale Nessun dato
