Extract Iron from High Acid Electrolyte

摘要

Iron can be transferred into electrolytes by chemical extraction and physical entrainment in the process of extraction and stripping stages. The current efficiency in the electrowinning operation decreases as the iron concentration in the electrolyte increases. As current efficiency decreases, electrowinning costs increase. Therefore, it is very important and necessary to remove iron from the electrolyte. The paper will discuss the use of a new reagent, Mextral Fe-180 (developed and investigated by KopperChem) to remove iron from the electrolyte. Results showed that: (i) when the concentration of Mextral Fe-180 is 10 %(v/v), it has a better extraction effect. The iron extraction efficiency can reach up to 90 % in a single stage contact with the electrolyte containing 3.0 g/L Fe, 35 g/L Cu and 180 g/L H_2SO_4 at an O/A ratio of 3:1. Under the same operating conditions, the iron extraction efficiency was almost 80 % in a single stage for the electrolyte which containing 6.0 g/L Fe, 35 g/L Cu and 180 g/L H_2SO_4; (ii) the addition of modifiers, such as TBP, MIBK, TDA, N503 and isooctyl alcohol into Mextral Fe-180 can improve the phase separation performance of the organics; (iii) the Fe extracted can be completely stripped with 2 mol/L NaOH at O/A ratio of 2:1; and (4) Test results show that any organic entrainment from the Mextral Fe-180 that is transferred into the main copper extraction circuit, does not affect the phase separation performance and the extraction performance of the main copper extraction system.