Abstract: The invention relates to a method for fully beneficating nickel sulfide concentrates or other corresponding mixtures, unsuitable for smelting, by combining the use of both pyrometallurgical and hydrometallurgical processes, so that there are formed two separate concentrates, the first of which is suited to pyrometallurgical and the second to hydrometallurgical treatment. In the concentrate going to pyrometallurgical processing, the valuable metal content increases as a consequence of the treatment, and the Fe/MgO ratio of this concentrate is at least 2.6.

Abstract: The invention relates to a method for mixing liquids into each other or different phases into liquid by employing a double loop circulation, created below the surface zone of a reactor, in order to maintain an intensive mixing. It is characteristic of this Bottom Toroidal Roll or BTR principle that the employed mixer has a strong bottom draft and presses obliquely downwards, and that the mixer is installed according to the mixing method of this invention and that the flow pattern thereof is controlled in an exactly determined fashion. In our method the mixer jet hits the cylinder surface of the reactor, so that the jet is divided into two roughly equal parts by adjusting this distribution by means of a back-flow guiding member of the invention, which guiding member is located above the mixer. The rolling motion taking place in the reactor is controlled by means of specific baffles.

Abstract: The present invention relates to a method for concentrating a certain mineral fraction attached to air bubbles from a slurry to the foam layer accumulated on the surface, so that the concentration takes place in three different mixing zones. The apparatus of the invention is formed of a colon-like flotation arrangement and of flow guides, a flow attenuator and an agitator belonging thereto. The flotation reactions are created in the bottom zone, wherefrom air bubbles and mineral particles carried by them are directed in a controlled fashion onto the surface of the apparatus. The flotation apparatus is so designed, that a strong agitation in the bottom zone can be used without causing harmful separation of the foam in the bottom part of the apparatus.