Ammonia Solution Of Extraction Of Copper And Crafts Ammonia Experimental Research

Tangdan copper ore, located near Dongchuan City in Yunnan Province, having copper reserve of 1.16×106 tons, is a refractory oxidized ore with high-alkaline gangues. Its average copper content is 0.46%, this oxidized copper mineral has 40% content of alkaline gangue. If acid-leaching method is adopted, it has high production cost because of huge acid consumption of alkaline gangue. In the "ammonia leaching-solvent extraction-electrowinning" process, there was a problem of ammonia extraction in the loaded organic phase when the two phase were contacted. The ammonia presented in the loaded organic phase should be removed before attempting copper stripping with the spent electrolyte. Otherwise, ammonia in the loaded organic phase is transferred to the pregnant electrolyte after copper stripping, which may result in the accumulation and the precipitation of (NH4)2SO4 in the pregnant electrolyte. The extraction of ammonia may bring many problems to the whole process and may be a waste of ammonia.In this paper, two different extractants were used to decrease the ammonia extraction in the loaded organic phase by deploying simple factor experiments. (1) A laboratory synthesized sterically hinderedβ-diketone was applied as a kind of extractant; (2) The other kind of extractant was LIX84 (a commercial extractant) adding TBP. The effects of the concentration of copper ion, the total ammonia concentration and initial pH in the aqueous phase, the concentration of extractant in organic phase, and the phase ratio on copper extraction ratio and ammonia extraction in loaded organic phase were studied.The experimental results show as follows:(1) When the laboratory synthesized sterically hinderedβ-diketone was applied, the copper extraction ratio was up to 95% at proper conditions, and the ammonia extraction content was no more than 40 mg/L. (2) Compared with absence of TBP, the high copper extraction ratio was almost unchanged while the ammonia extraction content was decreased manifestly. When the copper concentration in the aqueous phase and total ammonia concentration were 25 g/L and 3 mol/L, respectively, the pH of aqueous phase was 9.1. The organic phase was LIX84 concentration of 40% adding TBP of 0.1 mol/L. The phase ratio was 1:1. The contact time was 30 min. The result showed that the copper extraction ratio was 81% and the ammonia extraction in the loaded organic phase was 85 mg/L. While the copper extraction ratio and ammonia extraction in the loaded organic phase in the absence of TBP were 81% and 260 mg/L.