Pilot Plant Scale Development Of E-HNBPO Characterisation And Performance

摘要

Hydroxy Nonyl Benzo Phenone Oxime (HNBPO) has been used extensively singly or in combination with other oximes as extractant in solvent extraction of Copper and Nickel and other base metals from leach liquors of lean and off grade minerals for more than two decades. Henkel's Lix 64N was standard in industrial applications during seventies through early nineties. Several processes have been developed at RRL, Bhubaneswar for recovery of base metals from Indian Ocean nodules or complex sulphide minerals or from secondary sources, through Hydro metallurgical routes utilizing LIX 64N or its variants. With the objective of meeting the requirement of these reagents indigenously, work was taken up for developing economic processes for these materials from cheaply available raw materials. HNBPO, the main ingredient, which constitutes more than 95% of the active matter of LIX 64N, was hitherto being produced by the highly corrosive AlCl_3 catalysed Friedel-Crafts synthesis. We have developed a non-corrosive new process for the intermediate Hydroxy Nonyl Benzo Phenone utilizing the Phase transfer catalysed reaction of Nonyl phenol with benzotrichloride. The ketone was oximated with hydroxylamine sulphate, a bye product of GSFC and by a novel cold separation process, purified the HNBPO. Based on the bench scale studies on 500 g scale, pilot plant studies at GSFC have been carried out and the product was generated. Process on 250 g scale was developed for the kinetic promoter DEHDO starting from the commercially available 2-ethyl hexanoic acid. Different aspects of the development and its evaluation and experience in the scale up studies are described in the paper.