Degradation of hydroxyoxime extractants by nitration and remedies with inhibitor reagent

Abstract In this study, degradation of hydroxyoxime extractants by nitration was studied in nitrate media. The effect of nitrate concentration in the range of 10–40 g/L, pH value range of 1.5–2.3, temperature in the range of 25–35 °C and different modifiers including 2,2,4-trimethylpentanediol diisobutyrate, tridecyl alcohol and nonyl phenol on the nitration of hydroxyoxime extractants was investigated. A new type of inhibitor reagent consisted of tertiary butylhydroquinone (TBHQ) and styrolfenol blend (1:2, w /w) was investigated in a nitrate media under 180 g/L H 2 SO 4 at 30 °∁ for required time. It is shown that the new inhibitor reagent (3%, w /w) can reduce the nitration to half for hydroxyoxime extractants. In addition, other measures such as increasing the pH to above 2.3, using more stable reagents like ketoximes, to reduce nitration were suggested.