Abstract: A method and apparatus treat fiber based material so as to reduce the loss of mineral fractions in the treatment of broke in paper production. Broke is a reusable raw material from a paper machine that contains mineral fractions which are desirably returned to the process as a raw material. The material containing minerals is dispersed into broke pulp, which is fractionated, and the accepts from the fractionation are returned to the paper manufacturing process providing for efficient and economical recovery of the minerals in broke. The mineral fraction provided in the rejects from the fractionation is treated separately before it is reused as filler or coating material in the production of paper or board.

Abstract: Recycled fiber pulp from a vortex cleaning plant (e.g. connected to the short circulation of a paper machine) effects the recovery and return of fillers in the recycled fiber pulp discharged from the vortex cleaning plant, in an efficient and economical manner. The loss of filler in the recycled fiber pulp discharged from the vortex cleaning plant is decreased by treating a concentrated fraction of the rejects from the vortex cleaning plant with a mixer/disperser for dispersing the filler in the recycled fiber pulp, and returning as much usable filler as possible back to the process.