THIS RESEARCH WILL ALLOW TO ADOPT THE IMPERIAL SMELTING FURNACES OF THE EC TO TREAT ALL COMPLEX ZINC/COPPER CONCENTRATES. THE ECONOMIC BENEFIT WILL RESULT FROM THE POSSIBILITY OF TREATMENT OF COMPLEX CONCENTRATES (AVOIDING THE SEPARATION OF ZINC FROM COPPER) AND FROM THE RECOVERY OF COPPER.
The imperial smelting furnace (ISF) is an efficient means of producing zinc and lead from lower grade materials both of primary and secondary origin.
Since its initial development changes in concentrate mixes have increased the copper input into the furnace. This creates problems after the recovery of the zinc in the condenser and after the furnace is tapped.
These problems will need to be solved if the ISF is to be used in preference to electrolysis plants.
The copper at the top of the furnace originates mainly from carryover of fine materials charged and is transferred therefore not causing too many problems if the physical quality of the charge is high enough.
The ISF can not be economically operated with a continuous lead tapping since these new investments are heavy and do not bring improvements. In particular, the slag zinc content remains in average above those of furnaces running with a discontinous tapping.
However it has been shown that the ISF can accept during short periods, amounts of copper in their input corresponding to a content up to 12% in the lead buillon.
It is possible, using a special tapping procedure to decopperize continuously by quenching the raw lead tapped from the furnace. The copper dross is then a powdery material, and can be handled easily.
The kinetics of copper separation from lead is increased by a higher temperature, but the current technology can not accept it, because the materials used do not resist corrosion by lead at 700 to 800 C.
In consideration of this, a new scheme has been proposed for comprises a slow cooling in the 700 to 800 C temperature range in order to impose high demixition rates followed by quenching at 400 C of the lead bullion in order to succeed in the drossing/drying step, or a separation of the copper rich phase and then a quenching in order to produce a fractional product. This step is necessary for the development of new materials for lead strring at 800 C.
THE IMPERIAL SMELTING PROCESS, USED IN DIFFERENT COUNTRIES IN EUROPE CANNOT TREAT ORES WITH MORE THAN 1-2% COPPER. THE AIM OF THIS RESEARCH IS TO MAKE ALTERATION TO IMPERIAL SMELTING FURNACES IN ORDER TO IMPROVE THEIR FLEXIBILITY AS REGARD COPPER. IN THIS WAY ZINC-COPPER CONCENTRATES RESULTING FROM COMPLEX ORE BODIES COULD BE ECONOMICALLY TREATED.
THE RESEARCH IS DIVIDED IN THE FOLLOWING STEPS:
- MINERALOGICAL STUDIES OF CALCINES, ZINC-COPPER COMPOUNDS, ETC...
- INFLUENCE OF INCREASING COPPER CONTENT ON CRUDE ZINC COMPOSITION
- STUDIES CONCERNING THE BOTTOM OF THE FURNACE
- LEAD-COPPER BEHAVIOUR
- COPPER AND LEAD SEPARATION
- USE OF ELECTRIC FURNACE TO SEPARATE COPPER-LEAD.
Funding SchemeCSC - Cost-sharing contracts