A. Młynarczykowska

Flotation of Polish Hard Coal in Saline Water

With the use of process water (saline), the ash content in the concentrate was 6% and in the tailings up to 70%. Of course the upgrading plants which apply flotation for coal slurries still use mine water in technological processes. The water quality, particularly the content and type of salts in water, fundamentally influences the surface properties of phases which remain in contact during the process, that is the solid, gaseous and liquid phases. The properties of these phases and interactions between them determine the probability of occurrence of elementary flotation actions (Brozek and Mlynarczykowska, 2005, Brozek and Mlynarczykowska, 2008): collision, adhesion and separation, and ultimately the upgrading process effectiveness expressed by technological parameters. The paper presents the results of flotation effectiveness analysis for coal as a model raw material. The object of evaluation was qualitative parameters of the upgrading process products on the basis of flotation tests conducted for variable pulp salinity. The principal goal was to determine the impact of process water quality on the course and effectiveness of flotation.

An analysis of the velocity field distribution inside the flotation chamber

This paper presents the experimental data of the measured velocity field of a water and air-water system within a laboratory flotation chamber at various rotational speeds of the rotor and aeration. These results were used to verify the gas-phase distribution in the flotation chamber of a process conducted under specified hydrodynamic and physicochemical conditions. The PIV technique was used to determine the flow field in a number of planes; with this method non-invasive measurements of the velocity field in single and two-phase systems were carried out. An analysis of the results allows one to determine the parameters describing the hydrodynamic conditions in the flotation chamber and evaluate the effectiveness of the flotation process.