Rio Tinto Alcan International Limited

Alcan International Limited

Guy Simard

Alain Boivin

Guy Peloquin

Andrew N Carruthers

Matthieu St-Laurent

Renald Dufour

Deane Labrum

Pascal Vandal

Marie-Louise Bouchard

Alain Larouche

Veronique Savard

Régis Girard

Simon Gravel

Rock Lemyre

Regis Girard

A screw press for separating liquid from a solid-liquid mixture includes a casing having inlet and outlet sections, and a filter section there between. The filter section includes an axially extending stack of coplanar filtration plates defining a core passage for receiving a screw configured to convey the solid-liquid mixture from the inlet section to the outlet section while compressing and dewatering the solid-liquid mixture by forcing at least part of the liquid content of the mixture to be expelled out of the casing through inter-plate gaps defined between each pair of adjacent filtration plates. The filtration plates are fixed relative to one another and clamped in direct intimate face-to-face contact by a clamping assembly operable for applying a predetermined axially clamping pressure substantially uniformly about the core passage. The inter-plate gaps are controlled by the surface roughness of the plates and the clamping pressure.

Screw press with filter plates

A screw press includes a filter casing having inlet and outlet sections and a filter section therebetween. A screw is mounted in the casing for conveying a solid-liquid mixture from the inlet section to the outlet section while compressing the solid-liquid mixture and forcing at least part of a liquid content thereof to be expelled out of the filter casing. The casing and the screw are of modular construction. The filter section has at least first and second serially interconnectable filter sections, and the screw has at least first and second serially interconnectable screw sections respectively disposed in the first and second filter sections for joint rotation as a unitary component. The first and second screw sections have a continuous screw flight having a flight outside diameter. The first and second screw sections are detachably coupled to one another by a coupling provided at the outside diameter of the flight.

Modular screw press

An apparatus for refining a process liquor that includes solids, which apparatus includes a vessel having a base and a side wall that define an internal volume for containing the process liquor and for allowing gravity settling of the solids in the liquor, whereby to produce a refined liquor toward a top of the internal volume and a slurry toward a bottom of the internal volume, the apparatus further includes solids displacement elements disposed within the internal volume for directing settled solids and/or settling solids in the vicinity of the side wall or of the base toward a flow path of the slurry being extracted from the slurry outlet. A processing plant including the above refining apparatus and a method for refining a process liquor.

Apparatus and method for refining a process liquor by gravity settling

The invention relates to a settler for decanting mineral slurries and a method thereof. The settler comprises a tank for holding and decanting a body of slurry to form a thickened slurry as a lower layer and a clarified liquid as an upper layer, the tank having a side wall, a bottom and a top, an outlet for the thickened slurry at the bottom of the tank, an outlet for the clarified liquid layer near the top of the tank, a slurry inlet means near the top of the tank for introducing fresh slurry into the tank, the slurry inlet means having a slurry opening through which fresh slurry joins the body of slurry in the tank, and a stirrer having a generally vertical axis around which the stirrer rotates or reciprocates. The slurry opening is displaced laterally relative to the generally vertical axis of the stirrer and the slurry inlet means is configured to allow the fresh slurry to enter the slurry body without accumulating solids from the fresh slurry at the slurry opening.

Apparatus for and method of settling of mineral slurries

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La Malbaie, Canada

Guy Simard