1993 Volume 3

The effect of titanium dioxide, kaolin, calcium carbonate and talc on the properties of foams formed by sodium oleatelsodium stearate solutions and the flotation yield of these pigments in the presence of the same soaps have been investigated. In addition, the flotation of dispersed model coatings prepared from these pigments with styrene-butadiene and polyacrylate latexes was studied. The influence of coating colour composition and flotation chemicals (including silicate) was investigated using factorial experiments. The latexes strongly increase pigment floatability, but the effects are interrelated with the effects of other components in the coatings in a complex way. The flotation yield of the different pigments depend quite differently on the amounts of calcium and silicate added. This indicates that it may be possible to achieve flotation selectivity by proper design of flotation strategies. The factorial experiments also make it possible to draw some tentative conclusions with regard to mechanisms giving rise to the observed effects.

The pulp and paper industry has a fantastic potential to become the first and possibly the only truly “evergreen” industry. Our raw material is renewable, we apply sustainable forest operations, within the next decade our mills will be ecologically balanced, and our products are non-toxic and recyclable.

It is up to ourselves to “do-it-ourselves”, to take charge and to find new solutions which will prepare us for a future full of trend-breaks.

The key is knowledge and competence. Our fundamental task is to build up the knowledge-base that will be necessary if we are to proceed and if we want success.