Author: Publisher:
ISBN:
Category :
Languages : en
Pages : 10
Book Description
United States Patent : US4676828 : Process for the Leaching of Sulphides Containing Zinc and Iron
Author: United States Patent : US4004991 : Two-stage Pressure Leaching Process for Zinc and Iron Bearing Mineral Sulphides
Author: United States Patent : US6168766 : Process for Leaching Copper from Copper Sulfide Using Bacteria
Author: Leaching Process for Metal Sulphide Containing Minerals
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
A process for the treatment of zinc sulphide containing concentrates by leaching at lower pressures and temperatures than existing processes (Sherritt Gordon) but nevertheless has acceptable kinetics for industrial applications. The following steps are involved: 1. Contacting pulverised zinc sulphide containing material with an aqueous leach solution containing zinc, 5 to 50 gpl iron and a maximum of 20 gpl sulphuric acid, and at a temperature between 70 degrees C and 119 degrees C. (Note MP of sulphur is 119 degrees C) as the zinc dissolves iron precipitates. 2. Separate the leach liquor from the solids. 3. Purify the leach liquor from 2 as necessary and electrowin most of the zinc leaving a spent electrolyte containing regenerated sulphuric acid. 4. Contact the solids from 2 with the spent electrolyte from 3 causing re-dissolution of the iron precipitate and further leaching of zinc and other metal impurities. 5. Separate the solids and liquids from 4. 6. Utilising the leach solution from 5 as a major portion of the leach solution for step 1. By controlled conditions in leach 1 the zinc mineral-sphalerite - effectively acts as a neutralising agent enabling the iron to be precipitated from the solution. Zn + Fe2 (SO4) -- ZnSO4 + 5 degrees + 2FeSO4 (Eq 1). 2FeSO4 + 1/2O2 + H2SO4 -- Fe2(SO4)3 + H2O (Eq 2). 2FeSO4 + 1/2O2 + 3H2O -- 2 FeOOH + 2H2SO4 (Eq 3). 2FeOOH + 3H2SO4 -- Fe2(SO4)3 + 4H2O (Eq 4). Precipitation of iron (Eq 3) is associated with the production of sulphuric acid and only proceeds to equilibrium if conditions are correctly selected. Equations 1, 2 and 3 can be made to occur simultaneously and the iron precipitating as a filterable Goethite, which easily re-dissolves in return electrolyte.
The Leaching of Zinc Containing Sulphide Minerals
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
A process - an improvement on that described in our patent No. 800224 - for treating zinc sulphide materials ( and recovering at least some of sulphide as elemental sulphur) wherein the sub-divided material is firstly leached, under pressure at less than 119 degrees C, with a sulphate leach solution low in sulphuric acid and having a high iron content together with zinc and impurities in a manner causing iron to precipitate and subsequently leaching the residue and redissolving the iron precipitate with spend electrolyte containing regenerated sulphuric acid resulting from the treatment of the leach liquor obtained from the first leach step and wherein the leach solution from the subsequent leach step constitutes the starting leach solution for the first leach step. The second leach step is carried out in two stages; a first leach stage conducted at elevated pressure and elevated temperature (less than 119 degrees C - ie below the melting point of sulphur) in the presence of oxygen and a second stage at atmospheric pressure and without the supply of free oxygen to the leach solution.
United States Patent : Process of Recovering Copper and of Optionally Recovering Silver and Gold by a Leaching of Oxide-and Sulfide-containing Materials with Water-soluble Cyanides
Author: United States Patent : US5575334 : Copper and Zinc Recovery Process from Sulfide Ores
Author: United States Patent : US2727818 : Method of Leaching Copper Sulfide Materials with Ammoniacal Leach Solution
Author: Recent Advances in the Leaching of Sulphides and the Precipitation of Iron
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Recent advances in the leaching of sulphide concentrates and in the associated area of iron precipitation are examined. Sherritt Gordon's technology of pressure leaching with oxygen and sulphuric acid is being applied commercially to zinc concentrates. A Zn recovery of over 98 per cent is achieved, and the associated pyrite is largely unaffected; elemental sulphur is the principal sulphidic product. Leaching processes with ferric chloride or cupric chloride, or both, are being applied to a wide variety of sulphide concentrates. Duval's CLEAR cupric chloride leach process for copper concentrates has been evaluated at the demonstration-plant scale, and many other processes using FeCl3 or CuCl2, or both, for copper have been piloted. Several chloride leaching processes for lead or pyritic zinc concentrates have also been tested successfully at the pilot level. All the processes stress the advantages of the formation of elemental sulphur and the relative lack of pyrite attack. Equally important advances have been made in the elucidation of the fundamental leaching reactions involved. Technologies for the precipitation of jarosite, goethite, and hematite are being used routinely for the control of iron in both sulphate and chloride media, and efforts are currently being made to control metal losses (Pb, Zn, Cu, Ag, etc.) associated with these precipitates. Although ongoing research has clarified many aspects of iron precipitation, it has yet to find large-tonnage uses for the various iron precipitates.
Author: