ScreenFloat – Screening of flotation reagents–minerals interactions: a surface chemistry approach

Purpose and goal
There are several industrial relevant advantages with a fast screening method compared to the normal procedure used for testing of new ideas, i.e. batch-wise laboratory flotation tests. The main objective of this project was to provide a cost and time effective approach for testing of new reagents and new conditions in mineral flotation processes. The approach focused on evaluating a fast screening method to identify potential flotation reagents for a few specific minerals, combined with surface chemical characterisation for increased understanding.

Structure and implementation
The project included six technical work packages. The aim of WP1 was to perform a literature study and select materials. In WP2–5 tests using QCM method were followed by surface chemical characterisation of flat mineral surfaces. Focus in the different cases was to study adsorption on mineral surfaces and follow the effect of changes in pH and water quality, and the use of different collectors and depressants. Since more tests than planned were needed for the QCM method, WP5 with adsorption on mineral particles could not be included. In WP6 the result were compared to known flotation response.

Expected results
In this project, a screening method for in-situ studies of interactions between minerals and reagents was evaluated. For the minerals and process conditions chosen in the project the results show that ions are dissolved from the mineral surfaces, complicating the evaluation of data. Therefore, for the minerals and process conditions used the method did not work as planned, as a straightforward screening method. The surface chemistry characterisation method on the other hand provided very interesting information of adsorption of different flotation reagents on mineral surfaces.