Nitric Acid → HCID 178443865, compound

Participants

Reaction Steps

3.03 g of neodymium oxide containing 72.4% by weight of neodymium, 16.15 g of di(2-ethylhexyl)phosphoric acid (DEHPA), 80 g of methylcyclohexane (MCH) and 1.8 ml of nitric acid at 0.5 mol/l are introduced into a reactor made inert beforehand with argon. This amount of nitric acid corresponds to 0.06 molar equivalent of HNO3 relative to the neodymium. The mixture is stirred and brought to 80° C. until the presence of solid can no longer be distinguished visually, i.e., in this case, 3 h. The mixture is cooled. Three washes with 20 g of water are successively carried out in order to remove the inorganic residues. Each wash comprises a step of stirring for 30 minutes and then a step of separating by settling out, also for 30 minutes. 20 g, 19.5 g and then 19.5 g are thus recovered. The water/MCH azeotrope is subsequently distilled with a Dean Stark apparatus. A solution of neodymium di(2-ethylhexyl)phosphate in MCH, with a clear appearance, is thus obtained. It is characterized by a content of neodymium in solution of 2.05%, a residual free acidity expressed as percentage by weight of DEHPA of 1.59%, and a water content of 209 ppm. In this case, the molar ratios are the following: DEHPA/Nd=0.34 and water/Nd=0.08. The attack yield is 95%.

Provenance & Evidence