Molecular scale approach towards DTP behaviour on sulphide surfaces
Understanding of the adsorption mechanisms of collectors on mineral surfaces can lead to improved selectivity and recovery of the valuable minerals.
To separate valuable minerals from each other and from the gangue material, flotation is used. In this process certain chemicals called collectors are added to a water pulp of finely ground ore.
Typical collectors are dithiophosphates (DTP) and xanthates (Xan). These collectors bind to the mineral particles which then become hydrophobic and float to the surface of the flotation cell.
The binding is stronger to some minerals than others and for this reason different minerals can be separated, for instance are the collectors more strongly attached to galena (PbS) than to sphalerite (ZnS) so PbS can then be separated from ZnS.
The collectors do not bind to the undesired gangue material which is then left behind.
Two important problems are that some of the ZnS floats together with the PbS and that some of the gangue material also floats.
It would be beneficial to avoid these problems and a deeper understanding of what happens when the collector attaches to the mineral surfaces can be of importance for the solution.
In this project solid state NMR is combined with DFT calculations as a way to explain the behaviour of the collectors on the mineral surfaces of PbS and ZnS.
Adsorption of DTP will be performed on two or three component mixtures of ZnS/PbS/SiO2 (gangue material) to see the effect of the various components on the attachment of DTP.
Adsorption of a mixture of DTP and Xan will be performed on the same mineral mixtures to see the effect of two collectors in combination, because this is known to have synergistic effects on the flotation.
DFT calculations will be used on the systems to facilitate the interpretation of the NMR data and to give additional insight into the adsorption processes occurring.
Because of the large size of the systems to be studied these calculations must be performed on the national high performance computer clusters.
The project is financed by the Strategic Mining Research Program at the Swedish Governmental Agency for Innovation Systems (Vinnova) together with the mining companies Lundin Mining and New Boliden.
Contact
Anna-Carin Larsson
- Associate Professor
- 0920-491694
- anna-carin.v.larsson@ltu.se
- Anna-Carin Larsson
Updated: