The problems of very limited resources in our country accelerated the drive to find out waste mineral resources and their recovery processes.
In this project the recovery process of vanadium pentoxide from waste oil-slag was developed by solvent extraction technique with di (2-ethyl hexyl) phosphoric acid.
In initial batch tests, the effects of numerous variables on each unit process, that is, leaching, solvent extraction, stripping, precipitation were evaluated and methods for increasing the yield of each unit process were explored.
In continuous solvent extraction and stripping system, the effects of operating parameters such as pH, mixing time, settling time, concentrations of solvent and acid, ratio of organic to aqueous flow rate were investigated in box-type mixer-settlers.
The experimental results showed that optimum operating conditions in continuous extraction system were as follows:
concentration of vanadium in feed
for 0.572M D2EHPA 7g/l
mixing time 5 minute
settling time 12 minute
initial pH 1.6
ratio of organic to aqueous 3
Based on our operation conditions the total yield of this recovery process was evaluated as 82% and the purity of vanadium pentoxide was 99% after final treatment such as washing, drying, and calcination.
The economic aspects of the process was considered by plant design. With a production of 100 tons/year of vanadium pentoxide the total investment was 1.45 million dollars with the rate of return on investment of 17.8% and payout period was 3.7 years.
