Abstract: An apparatus for the wet attrition of particulate material comprising an attrition scrubber; a dewatering screen comprising a deck and a sump beneath the deck, the dewatering screen being mounted upstream of the attrition scrubber whereby oversize material from a downstream end of the deck of the dewatering screen passes into the attrition scrubber; and a hydrocyclone wherein an underflow, containing a coarser fraction of the feed slurry, passes out of a lower outlet of the hydrocylone while an overflow, containing a finer fraction of the feed slurry and most of the water, passes out of an outlet at the upper end of the hydrocyclone, a pump being provided for pumping material from the sump of the dewatering screen to the inlet of the hydrocyclone, wherein the underflow from the hydrocyclone is passed into the attrition scrubber.

Abstract: A multi-deck screening assembly includes upper and lower screen decks, each having first and second deck sections. The upper deck's first deck section has first-size grading apertures, and its second deck section is downstream of the first deck section with second-size grading apertures larger than the first-size apertures. The lower deck's first section has third-size grading apertures and its second section is downstream of its first section with fourth-size grading apertures larger than the third-size apertures. A gap between the lower deck's first and second sections allows oversize material from the lower deck's first section to pass through to a first collection region. A diverter is positioned between the upper and lower decks and over the gap, whereby material from the upper deck collected on the diverter passes onto the lower deck's second section, thereby preventing undersize material that passes through the upper deck from passing directly through the gap.

Abstract: A multi-deck screening assembly includes upper and lower screen decks, each having first and second deck sections. The upper deck's first deck section has first-size grading apertures, and its second deck section is downstream of the first deck section with second-size grading apertures larger than the first-size apertures. The lower deck's first section has third-size grading apertures and its second section is downstream of its first section with fourth-size grading apertures larger than the third-size apertures. A gap between the lower deck's first and second sections allows oversize material from the lower deck's first section to pass through to a first collection region. A diverter is positioned between the upper and lower decks and over the gap, whereby material from the upper deck collected on the diverter passes onto the lower deck's second section, thereby preventing undersize material that passes through the upper deck from passing directly through the gap.

Abstract: An apparatus for the wet attrition of particulate material comprising an attrition scrubber; a dewatering screen comprising a deck and a sump beneath the deck, the dewatering screen being mounted upstream of the attrition scrubber whereby oversize material from a downstream end of the deck of the dewatering screen passes into the attrition scrubber; and a hydrocyclone wherein an underflow, containing a coarser fraction of the feed slurry, passes out of a lower outlet of the hydrocylone while an overflow, containing a finer fraction of the feed slurry and most of the water, passes out of an outlet at the upper end of the hydrocyclone, a pump being provided for pumping material from the sump of the dewatering screen to the inlet of the hydrocyclone, wherein the underflow from the hydrocyclone is passed into the attrition scrubber.

Abstract: A multi-deck screening assembly includes a plurality of vertically-stacked downwardly-sloping screen decks, each with grading apertures through which under-sized material may pass, while over-sized material passes over a lower discharge end of each screen deck. The screen decks are mounted on a common frame, which is mounted on a chassis and provided with vibration device. The screen decks include an upper deck, an intermediate deck below for receiving under-sized material from the upper deck, and a lower deck below the intermediate deck for receiving under-sized material from the intermediate screen deck. A first chassis-mounted stockpile conveyor receives over-sized material from the lower deck, a second chassis-mounted stockpile conveyor receives over-sized material from the intermediate deck, and a third stockpile conveyor receives over-sized material from the upper deck.

Abstract: A screening apparatus for grading particulate material includes a grading screen having apertures for water and/or undersize particles to pass through. The grading screen is supported on a frame mounted on a chassis via resilient linkages, and the grading screen being vibrated by a vibrating device that imparts circular or reciprocating motion to the grading screen. The grading screen is set at a predetermined slope whereby material to be graded can be delivered onto an upper end while the grading screen is vibrated to convey the material over the grading screen and to cause undersize material to pass through the apertures. Oversize material is discharged from a lower end of the screen onto a conveyor or into a collection bay or hopper. A sump beneath the grading screen receives under-sized material passing through the grading screen, and a jet pump conveys material from the sump to a dewatering screen.

Abstract: A screening apparatus for grading particulate material includes a grading screen having apertures for water and/or undersize particles to pass through. The grading screen is supported on a frame mounted on a chassis via resilient linkages, and the grading screen being vibrated by a vibrating device that imparts circular or reciprocating motion to the grading screen. The grading screen is set at a predetermined slope whereby material to be graded can be delivered onto an upper end while the grading screen is vibrated to convey the material over the grading screen and to cause undersize material to pass through the apertures. Oversize material is discharged from a lower end of the screen onto a conveyor or into a collection bay or hopper. A sump beneath the grading screen receives under-sized material passing through the grading screen, and a jet pump conveys material from the sump to a dewatering screen.

Abstract: A multi-deck screening assembly includes a plurality of vertically-stacked downwardly-sloping screen decks, each with grading apertures through which under-sized material may pass, while over-sized material passes over a lower discharge end of each screen deck. The screen decks are mounted on a common frame, which is mounted on a chassis and provided with vibration device. The screen decks include an upper deck, an intermediate deck below for receiving under-sized material from the upper deck, and a lower deck below the intermediate deck for receiving under-sized material from the intermediate screen deck. A first chassis-mounted stockpile conveyor receives over-sized material from the lower deck, a second chassis-mounted stockpile conveyor receives over-sized material from the intermediate deck, and a third stockpile conveyor receives over-sized material from the upper deck.

Abstract: A sludge conditioning apparatus includes at least one hopper for receiving waste water having solid impurities entrained therein, wherein the solid impurities settle out of suspension to be collected in a lower region of the hopper as sludge. The hopper includes a sludge outlet at a lower end thereof communicating with a pump for removing sludge therefrom. A sensing device is provided for determining the amount of sludge collected in the hopper, and the rate at which the sludge is removed by the pump is controlled by a control device, the control device controlling the operation of the pump to control the rate of removal of the sludge as a function of the output of the sensing device.