Obiettivo THE AIM OF THE STUDY IS TO PRODUCE, INSTEAD OF JAROSITE AND GEOTHITE, RELATIVELY STABLE FERROUS RESIDUES ABLE TO BE DUMPED WITHOUT CAUSING POLLUTION, AND TO ENSURE GOOD RECOVERY OF THE METALS PRESENT IN ZINC ORE. FOR SEVERAL ZINC PROCESSING PLANTS IS A CRUCIAL PROBLEM FROM BOTH POINTS OF VIEW: OPTIMUM METAL RECOVERY AND ENVIRONMENTAL CONSIDERATIONS. Plants for the electrolytic recovery of zinc produce a neutral leach residue which may be treated in a number of ways. This work aimed to develop another treatment which would have a low operating cost and would produce an iron residue suitable for dumping.Pyrometallurgical routes appear to be the most attractive, producing an inert iron residue for disposal. Electric furnaces seem to be the most economical of those tested, although requiring a high initial investment. Nevertheless, these furnaces also produce flue dusts containing metals of value to the economy of the total procedure. Another alternative would be the treatment of the iron residue in the blast furnace of a nearby lead plant.The objective of the research was to find alternative ways of performing the iron bleed of electrolytic zinc plants through new routes of treating the neutral leach residue. Processes were tested which enabled the production at low operating costs, of iron residues that are more easily dumpable than the present ones.The study looked at the feasibility of changing the hot leaching and iron precipitation steps in present electrolytic zinc plants for a pyrometallurgical step (electric furnace smelting of the neutral leach residue). This would enable the bleeding of the iron content of zinc concentrates treated in electrolytic zinc plant and the recovery of the zinc content of the neutral leach residue in the fumes of the pyrometallurgical furnace.Knowing the partitioning and the constitutive phases of neutral leach residue and the possible reactions in reducing conditions. It was possible to calculate, through mass and heat balances, working conditions and size of an electric furnace for the treatment of zinc ferrites.A comparison was made of different pyrometallurgical furnaces for the treatment of neutral leach residue in reducing conditions. Electric and Cupola furnace processes had the advantage of producing a silver bearing matte for silver recovery. The electric furnace process was very attractive because of the smaller energy consumption and gas output flow rate.The Waelz kiln did not need any feed preparation, whereas the electric furnace process needed only small feed preparation but the Cupola furnace needed a larger one.So, the electric furnace remained the most attractive and could be the most interesting to invest in even if its investment cost is high.THE AIM OF THE RESEARCH IS TO MODIFY THE ANACONDA PROCESS (ELECTROLYTIC RECOVERY OF ZINC IN AN AQUEOUS MEDIUM) IN ORDER TO AVOID CONTROLLED DUMPING OF FERROUS RESIDUES, WHETHER GOETHITE OR JAROSITE, AND TO ENSURE GOOD RECOVERY OF THE METALS AND LOW OPERATING COSTS. THE RESEARCH WILL BE CARRIED OUT ON SAMPLES FROM THE PREUSSAG-WESER-ZINC AND PERTUSOLA SUD PLANTS AND WILL CONCENTRATE ON TWO MODIFICATIONS TO THE PROCESS. 1.- FIRST MODIFICATION STUDY OF CALCINE ENRICHMENT BY ELIMINATION OF ALL PHASES OTHER THAN THOSE CONSISTING OF SOLUBLE ZINC SALTS AND OXIDES IN A SULPHURIC MEDIUM, THUS REDUCING THE FERRITE CONTENT. 2.- SECOND MODIFICATION TO LEAVE THE LEACH INTACT WITHOUT DISSOLVING THE FERRITE AND TO MODIFY THE TREATMENT OF THE RESIDUE. TWO METHODS ARE TO BE TESTED: .- DIRECT REDUCTION SMELTING OF THE ANACONDA RESIDUE IN AN ELECTRIC OVEN. IF SUCCESSFUL, THE METHOD WILL BE TESTED FOR VERSATILITY. .- PHYSICAL SEPARATION (EG BY MAGNETIC SEPARATION OR FLOTATION) OF THE ANACONDA RESIDUE, WITH THE AIM OF RECOVERING A) A HIGH VALUE SILVER ZINC CONCENTRATE AND B) A RESIDUE CONTAINING MOST OF THE ZINC AND LEAD, WHICH COULD BE TREATED EXPERIMENTALLY IN A WAELZ TUBE. Campo scientifico natural scienceschemical sciencesinorganic chemistrytransition metalsnatural sciencesearth and related environmental sciencesenvironmental sciencespollution Programma(i) FP1-RAWMAT 3C - Research programme (EEC) on materials (raw materials and advanced materials), 1986-1989 Argomento(i) Data not available Invito a presentare proposte Data not available Meccanismo di finanziamento CSC - Cost-sharing contracts Coordinatore Preussag-Weser-Zink GmbH Contributo UE Nessun dato Indirizzo Rammelsberger Straße 2 38640 Goslar Germania Mostra sulla mappa Costo totale Nessun dato Partecipanti (1) Classifica in ordine alfabetico Classifica per Contributo UE Espandi tutto Riduci tutto Métaleurop Recherche SA Francia Contributo UE Nessun dato Indirizzo 1 avenue Albert Einstein 78193 Trappes Mostra sulla mappa Costo totale Nessun dato
