Predicting plant scale flash flotation performance - Validation of laboratory methodology and applications for use

摘要

A method has been developed in which laboratory batch flotation test results can be used in conjunction with mineralogical analysis to determine whether an ore is amenable to successful recovery via the flash flotation processing route. In the original development work, using a high grade refractory gold ore, a direct correlation was found with the particle properties of the plant flash flotation cell concentrate and a concentrate produced by a targeted laboratory batch flotation test. The respective concentrates were observed to have nearly identical distributions of the target elements (Au, S and Fe) by size as well as almost identical liberation characteristics of the key mineral (pyrite) for flotation. A second ore from the same mine, but of significantly lower grade and different grinding characteristics has now been tested to determine if the same correlations exist that were observed with the previous work and to provide fur-ther insight into the differences between laboratory and plant response in order to potentially refine the procedure further and enhance its usability as a predictive tool. Testing of the second ore confirmed the original findings that a targeted laboratory batch flotation test can produce a concentrate with a target mineral (pyrite) distribution by size and liberation that matches the concentrate produced by the industrial scale flash flotation cell whilst treating the same feed mate-rial. Further to this, grades of the intermediate size classes in the laboratory concentrates were found to be similar to those of the plant flash cleaner cells. From the correlations in performance observed with both ore types in the laboratory batch cell and plant flash flotation cell, methodologies are proposed that can be used to determine: whether a new ore could be treated by flash flotation in a plant with an existing flash flotation circuit; whether a plant operating without an existing flash flotation circuit could benefit from installing one; and the amenability of an ore to the flash flotation process for greenfield flow sheet development. A step wise approach is given for each to allow the method to be applied to and adapted for other ores and valuable mineral types. The advantage of following this methodology exists in that no specialised equipment or analysis methods are required to perform the test. Standard laboratory equipment has been used throughout the test-work and mineralogical analysis performed via commercially available MLA. The procedure is kept as basic as possible to allow for maximum usability on sites where only essential laboratory equipment exists.