A concrete recycling system and a method of use thereof is disclosed. The concrete recycling system may recycle aggregates and sand from fluid-concrete based on their grain size. Particularly, the concrete recycling system may have a slurry refiner that allows for the finer aggregates in the fluid-concrete to be recycled. The fluid-concrete may be diluted by water and fed to the slurry refiner via a fluid outlet having a turbulent discharge. The slurry refiner may allow the finer aggregates to settle to the bottom of said device for an auger system to uniformly mix the aggregates and transfer them along the length of the slurry refiner. The uniformly mixed slurry may then be pumped to a hydrocyclone to separate the finer aggregates from the cement and water in the slurry.

An agitator for a gypsum wallboard mixer is provided and includes a circular disc with an upper surface, a drive shaft extending vertically from the upper surface, a lump ring secured to the upper surface, the lump ring being provided in a plurality of spaced, adjacent arcuate segments.

A mixer (1) comprises a drum (2) having at least one inlet (6) and one outlet (7). The mixer (1) furthermore comprises a drive (3) and a stirring shaft (4), which is arranged in the drum (2) and is coupled to the drive (3). Furthermore, the mixer (1) comprises a conveying device (5), which is arranged in the drum (2) and which is arranged on one and the same axis as the stirring shaft (4).