A process for recovery of solids from a drilling fluid includes the steps of passing a solids-containing drilling fluid through a grinder, grinding the solids from the drilling fluid to a desired size, pumping the ground solids and the drilling fluid to hydrocyclone such that the hydrocyclone produces an overflow and an underflow. The overflow contains low-density solids and the underflow contains high-density solids. The high-density solids are passed to a container. The solids-containing drilling fluid is shaken prior to the step of grinding so as to remove oversize solids from the drilling fluid. The ground solids are pumped to the hydrocyclone at a generally constant pressure.