A drum assembly for a ball mill system may comprise: a drum having a first flange extending axially forward from a first radial wall, a second flange extending axially aft from a second radial wall, and a cylinder shell extending axially from a first radially outer end of the first radial wall to a second radially outer end of the second radial wall; a frame coupled to the first flange; and an inlet liner coupled to the frame, the inlet liner comprising a plurality of inlet segments disposed circumferentially adjacent to each other, the inlet liner defining an inlet radius for the drum assembly.

Methods for cost effectively transforming lower quality silica sands into higher quality silica sands for use as proppants in fracking operations involving subterranean hydrocarbon formations. A process of exposing silica sand proppants to locally-sourced electromagnetic radiation, and systems therefor, are disclosed and shown to increase the performance of those silica sands as proppants in hydrocarbon formation fracturing operations.

Methods for cost effectively transforming lower quality silica sands into higher quality silica sands having increased crush resistance for use as proppants in fracturing operations involving subterranean hydrocarbon formations. One or more of an attrition process, a microwaving process and a tumbling process are disclosed and shown to be applied to silica sands having inferior physical properties in order to increase the performance of those silica sands as proppants in hydrocarbon formation fracturing operations.

A discharge end wall system including a discharge wall assembly in which a number of pulp chambers are defined, and one or more plug elements at least partially occupying one or more of the pulp chambers.

A sleeve insert for covering one or more selected surfaces of one or more pulp lifters of a discharge end assembly including a discharge end wall of a mill shell partially defined by an outer perimeter wall thereof, the pulp lifters being mounted on the discharge end wall. The sleeve insert is formed to cover the selected surfaces to mitigate wear to which the selected surfaces are subjected when the sleeve insert is located in a predetermined position relative to the selected surfaces.

Disclosed is a method for manufacturing calcium zincate crystals including: placing calcium hydroxide.sub.2 and zinc oxide, one of the precursors thereof, or one of the water mixtures thereof in a starting suspension, the mass ratio of water to calcium hydroxide and zinc oxide, or one of the precursors or mixtures thereof, being greater than or equal to 1; milling the starting suspension to an ambient temperature less than or equal to 50 C. in a wet-phase three-dimensional micro-ball mill for a residence time less than or equal to 15 minutes and in particular from 5 to 25 seconds; recovering a calcium zincate crystal suspension coming out of the mill; and optionally, concentrating or drying the calcium zincate crystal suspension so as to obtain a calcium zincate crystal powder. Also disclosed are uses associated with the calcium zincate crystals obtained according to the method described above.

A preliminary size reduction device for a ball mill or agitator ball mill and a ball mill with a preliminary size reduction device, wherein the preliminary size reduction device is disposed between a grinding stock inlet of the ball mill or agitator ball mill and a grinding chamber and includes a first size reduction mechanism constituted stationary and a second, rotationally mobile size reduction mechanism, between which a size reduction gap is formed. The first size reduction mechanism constituted stationary is a size reduction ring disposed in the grinding container.

An insert for covering one or more selected surfaces of a discharge end assembly including a discharge end wall of a mill shell partially defined by an outer perimeter wall thereof and a number of pulp lifters mounted on the discharge end wall. The insert is formed to cover the selected surfaces to mitigate wear to which the selected surfaces are subjected when the insert is located in a predetermined position relative to the selected surfaces.

Methods and systems for cost effectively transforming lower quality sands into higher quality sands for use as proppants in fracking operations. One or more of an attrition process, a microwaving process and a tumbling process, and systems therefor, are disclosed and shown to be applied to sands having inferior physical properties in order to increase the performance of those sands as proppants in hydrocarbon formation fracturing.

A monitoring device in the form of a camera in a protective housing is fixed to an outlet assembly of a feed chute and in a particular embodiment to a flange that extends outwardly about an outlet of the outlet assembly. The flange also supports a light also in a protective housing. The feed chute feeds ore into a grinding mill. The housings for the camera and light contain a viewing window which is cleaned by water jets and the window is protected by a visor which can be opened when the interior of the mill is to be recorded. The arrangement allows the interior of the mill to be monitored while the mill is grinding the ore.