A Comparative Study of Kinetics of Flotation of a Copper-Nickel Ore by N-Hydrocinnamoyl-N-Phenylhydroxylamine (HCNPHA) Vis-A-Vis Potassium Amyl Xanthate (PAX)

Flotation kinetics was studied for the flotation of Canad-ian nickel ore using N-hydrocinnamoyl- N-phenyl-hydrox-ylamine (HCNPHA) as the collector. The differential flotation between pentlandite and pyrrhotite of HCNPHA was compared by repeating the experiments with potassium amyl xanthate (PAX). However, the pH for the flotation was 9.0 and 9.5, respectively, for using HCNPHA or PAX as collec-tor. Time-recovery plots were fit using the modified first order rate equation for flotation kinetics, namely, 12, = ev"), and flotation rate constant and the cumulative recovery at time infinite (R,) were computed. HCNPHA was found to react with pentlandite slightly faster than PAX. However, HCNPHA was found to float more pyrrhotite and silica than PAX thus the grade of the concentrates were adversely affected

Structure-Activity (Flotation) Relationship Modeling of Flotation of Sphalerite by N-Arylhydroxamic Acids

Molecular structure is known to play a vital role in the efficiency of chleating collectors in mineral flotation. Hence, flotation efficiencies of congeneric organic compounds used as mineral collectors are amenable to QSAR modeling. Sphalerite grade of the floats of a set of flotation tests conducted with a copper-zinc ore using a series of twenty seven Narylhydroxamic acids of the generic structure Ar-N(OH)C(=0)-R (R= arylialkyliaaralkyl) were modeled using calculated molecular descriptors such as, topochemical, topostructural, quantum chemical, and geometrical parameters. In addition to these molecular descriptors, calculated physicochemical properties such as octanol-water partition coefficient (ClogP), and orga-nic carbon-water partition coefficient (logKoe) were also used to build the regression models. The collectors were classified into C-aryl, C-alkyl, and C-aralkyl. Octanol-water partition coefficient (ClogP) was found to give the best quadratic fit for C-aryl, and the combined set of C-aralkyl and C-alkyl. It was interesting to note that the data for individual sets namely, C-alkyl, and C-aralkyl gave linear fits with positive and negative slopes, resp-ectively. This indicated that the points were distributed on the right hand and left hand sides of the parabola that fits the combined data set

QSAR modeling of flotation collectors Part 1-Application of valence connectivity indices to the flotation of a uranium ore using substituted-cupferrons^†

130-134Cupferron and substituted-cupferrons are used as collectors for the flotation of a Canadian uranium ore. Valence connectivity indices are calculated for these compounds and stepwise multiple regression analysis is performed to select a best regression model to predict the separation efficiencies. Four of the compounds, p-fluoro, p-chloro, p-mothoxy and 2,4,6-trimethyl-cupferrons are found to be the outliers. Stepwise regression analysis using the topological indices selects fifth order connectivity index, 5v to form a regression model with the highest F-score and a correlation coefficient of 0.908