Objective
The aim of this industrial process will be: the recovery of impure lead which could easily be purified in a pyrometallurgical lead refining plant; the recovery of zinc and cadmium as products easy to recycle in the nonferrous metallurgy; and the obtention of a bleed of sulphur that might be dumped and would not give any problem of sulphur dioxide emission.
The work to be carried out consists of :
process research on each of the 3 steps, leaching (iron(III) chloride and chlorine), electrolysis (electrowinning of lead) and bleed (zinc recovery and elimination of impurities);
balance calculation with a computerized model;
and technical and economical evaluation of different processes.
The research programme to be carried out is divided into different parts, which are not independent. In the leaching part, the main studies will be based upon: acid preleaching; effect of the medium on leaching efficiency; stability of the solution, treatment of the residue; and environmental problems.
In the electrolysis part the main studies will consist of: chemical studies; technological studies; and the quality of lead. The structure and chemical composition of the lead powder may influence its ability to be compacted and the yield of the melting stage. The effect of variations of the composition of the solution (major and minor impurities) will be studied.
In the bleed part of the research, 3 different processes may be used (or any combination of these): cementation; liquid liquid extraction; and the use of resins. In cementation, the reaction will lead to the reduction of cadmium, lead and thallium so a separation of cadmium has to be done previously to the cementation (a mist product lead cadmium is difficult to valorize).
The liquid liquid extraction of zinc and cadmium will be studied with acid basic or complexing extractants.
In order to evaluate all the problems dealing with any process choice, it will be necessary to have a computerized model.This model will calculate the flow of any major elements and will allow evaluation of the problems that might arise from water and chloride balances, as from the bleed flow rate.
Technico-economical performance of processes will be jointly evaluated and compared with existing processes.
Fields of science
- natural scienceschemical scienceselectrochemistryelectrolysis
- natural scienceschemical sciencesinorganic chemistrytransition metals
- natural scienceschemical sciencesinorganic chemistrypost-transition metals
- natural scienceschemical sciencesinorganic chemistryhalogens
- engineering and technologymaterials engineeringmetallurgy
Topic(s)
Data not availableCall for proposal
Data not availableFunding Scheme
CSC - Cost-sharing contractsCoordinator
78193 Trappes
France