A liquid solids separator includes a liquid receiving tank, a cascade tank, and a settling tank fluidically connected in series. Wastewater is recycled through the tanks beginning with the liquid receiving tank and contacted with hot gas in the cascade tank to concentrate the wastewater and remove solids that settle in the settling tank.

A liquid solids separator includes a liquid receiving tank, a cascade tank, and a settling tank fluidically connected in series. Wastewater is recycled through the tanks beginning with the liquid receiving tank and contacted with hot gas in the cascade tank to concentrate the wastewater and remove solids that settle in the settling tank.

A process for producing alumina trihydrate includes a digestion step, a separation step, and a precipitation step the separation step including: b1) pretreating a slurry from the digestion step by adding a flocculant to said slurry and mixing the flocculant and the slurry, b2) settling the resulting flocculated slurry in a gravity settler vessel, b3) determining a measured value representative of the concentration of solid particles in the resulting clarified liquor, b4) comparing the measured value with a predetermined threshold, b5) feeding said clarified liquor directly to the precipitation step, while the measured value is less than said predetermined threshold, and b6) redirecting said clarified liquor to the pre-treatment step b1), when the measured value is more than said predetermined threshold. An installation may be configured for operating said process.

A process for producing alumina trihydrate includes a digestion step, a separation step, and a precipitation step the separation step including: b1) pretreating a slurry from the digestion step by adding a flocculant to said slurry and mixing the flocculant and the slurry, b2) settling the resulting flocculated slurry in a gravity settler vessel, b3) determining a measured value representative of the concentration of solid particles in the resulting clarified liquor, b4) comparing the measured value with a predetermined threshold, b5) feeding said clarified liquor directly to the precipitation step, while the measured value is less than said predetermined threshold, and b6) redirecting said clarified liquor to the pre-treatment step b1), when the measured value is more than said predetermined threshold. An installation may be configured for operating said process.

A settler for decanting mineral slurries includes a tank having a side wall, a bottom and a top, an outlet for a thickened slurry at the bottom of the tank, a first overflow outlet for withdrawing an overflow stream of a clarified liquid, a slurry inlet means for introducing fresh slurry into the tank, the slurry inlet means having a slurry opening through which fresh slurry joins a body of slurry in the tank, and a stirrer having a vertical axis around which the stirrer rotates or reciprocates, in said settler the slurry opening is displaced laterally relative to said vertical axis of the stirrer and said slurry inlet means comprises mixing means. A separation installation includes the above settler and a method for separating a clarified liquid from a thickened slurry of a mineral slurry.

A settler for decanting mineral slurries includes a tank having a side wall, a bottom and a top, an outlet for a thickened slurry at the bottom of the tank, a first overflow outlet for withdrawing an overflow stream of a clarified liquid, a slurry inlet means for introducing fresh slurry into the tank, the slurry inlet means having a slurry opening through which fresh slurry joins a body of slurry in the tank, and a stirrer having a vertical axis around which the stirrer rotates or reciprocates, in said settler the slurry opening is displaced laterally relative to said vertical axis of the stirrer and said slurry inlet means comprises mixing means. A separation installation includes the above settler and a method for separating a clarified liquid from a thickened slurry of a mineral slurry.

An apparatus for wastewater filtration having a barrel, a basket and a screw on a shaft rotating therein for pushing solid in a distinct output. A removable cartridge comprises a cover for the barrel, the cartridge comprising a pre-sealed shaft connector which releasably connects to at least the upper shaft portion or the lower shaft portion to form the shaft. The screw comprises a brush on an outer rim thereof, the brush having radially outwardly oriented bristles that scrape an inner surface of the basket. The screw comprises a winged wiper at a bottom thereof for sweeping a bottom surface of the barrel, and the solid-material output is provided at the bottom surface of the barrel and is shaped as a rectangular opening which is offset from a central axis of the screw. Solid removal efficiency and maintenance are thereby improved.

An apparatus for wastewater filtration having a barrel, a basket and a screw on a shaft rotating therein for pushing solid in a distinct output. A removable cartridge comprises a cover for the barrel, the cartridge comprising a pre-sealed shaft connector which releasably connects to at least the upper shaft portion or the lower shaft portion to form the shaft. The screw comprises a brush on an outer rim thereof, the brush having radially outwardly oriented bristles that scrape an inner surface of the basket. The screw comprises a winged wiper at a bottom thereof for sweeping a bottom surface of the barrel, and the solid-material output is provided at the bottom surface of the barrel and is shaped as a rectangular opening which is offset from a central axis of the screw. Solid removal efficiency and maintenance are thereby improved.

A headrace system 1 improving a scum generation function of the headrace distributing and supplying raw water to a sedimentation basin provided in a sewage treatment plant to contribute to energy savings in the sewage treatment plant as a whole and contribute to solving environmental problems, which is provided with a buoyant imparting means 20 configured with including an ejector 22, in a side in which the raw water of a headrace body 2 to which the raw water is supplied or in the raw water flowed into the headrace 2 to impart buoyant force to solid matters contained in the raw water, and scum removing means 4, 8, 9, 10, 40a, and 40b removing scum S floating on a water surface of the headrace body 2.

A headrace system 1 improving a scum generation function of the headrace distributing and supplying raw water to a sedimentation basin provided in a sewage treatment plant to contribute to energy savings in the sewage treatment plant as a whole and contribute to solving environmental problems, which is provided with a buoyant imparting means 20 configured with including an ejector 22, in a side in which the raw water of a headrace body 2 to which the raw water is supplied or in the raw water flowed into the headrace 2 to impart buoyant force to solid matters contained in the raw water, and scum removing means 4, 8, 9, 10, 40a, and 40b removing scum S floating on a water surface of the headrace body 2.