A slurry mixer comprises a container assembly and pressurized air delivery system for mixing gravitationally separable heavy particulate of target slurry. The container assembly essentially comprises an inferior container portion, a superior container portion, a vertical container diameter, and accumulator plates, which plates are spatially located in superior adjacency to the inferior container portion orthogonal to the vertical container diameter. The air delivery system delivers compressed air to a gas outlet cooperable with the accumulator plates for outletting gas into the container assembly. The accumulator plate feature functions to plate-shape the outlet gas into a substantially planar initial bubble shape. The initially planar bubble shape is upwardly directed toward the superior tank portion in radial adjacency to the vertical container diameter. The outlet gas displaces slurry components via dynamic matter-displacing bubble action, and the initially planar bubble shape maximizes the matter-displacing effectiveness of the bubble action for mixing the slurry.