Aqueous slurry which includes solid foreign matter and paper dust is pressed by means of a screw press, provided with a mesh having openings not less than 1.5 mm and not greater than 3 mm, to separate the aqueous slurry into the solid foreign matter and the paper dust, and liquid component passing through the mesh. Then, the liquid component is sieved by means of a sieve having openings not greater than 1 mm to separate from the liquid component the solid foreign matter and the paper dust.

An apparatus and process mechanically remove hydrocarbons and other contaminants from solids through high energy slurry impact with a stationary plate or through high energy slurry impact of two or more slurry streams. In addition to the mechanical process, a gas additive, such as CO.sub.2, in solid, liquid or gas form, can be introduced into the slurry stream. The presence of gas additive can aid in the liberation of the contaminant. The process can increase efficiencies, reduce costs and improve thoroughness of contaminate cleaning in conjunction with aqueous pressure and sheer energy.

An apparatus and process mechanically remove hydrocarbons and other contaminants from solids through high energy slurry impact with a stationary plate or through high energy slurry impact of two or more slurry streams. In addition to the mechanical process, a gas additive, such as CO.sub.2, in solid, liquid or gas form, can be introduced into the slurry stream. The presence of gas additive can aid in the liberation of the contaminant. The process can increase efficiencies, reduce costs and improve thoroughness of contaminate cleaning in conjunction with aqueous pressure and sheer energy.

A treatment device for treating a mixture of at least a liquid, organic solids and inorganic, mineral solids, includes a container for receiving the mixture. The container tapers in a funnel shape in a direction of a longitudinal axis of the container. An inlet tangentially supplies the mixture to the container. An outlet discharges the liquid essentially containing the organic solids from the container. A discharge apparatus serves for discharging the inorganic, mineral solids. The treatment device also includes a sleeve adapted to guide the mixture between an outer wall of the sleeve and an inner wall of the container and to guide the liquid containing the organic solids within an inner wall of the sleeve for discharge from the outlet.

An apparatus for washing and grading sand includes a first vibrating screen having a deck arranged to receive a feed material. Oversize material passes over the deck of the first vibrating screen for collection as a first product, and undersize material and water are collected in a sump of the first vibrating screen before being pumped to a hydrocyclone. A second vibrating screen receives an underflow from the hydrocyclone upon a deck thereof, with oversize material passing over the deck of the second vibrating screen for collection as a second product. An overflow from the hydrocyclone passes into a settling tank, and a water storage reservoir receives water overflowing from the settling tank while sludge is collected and removed from a lower end of the settling tank. Water is passed from the water storage reservoir to the first and second vibrating screens to wash and fluidise material thereon.

A solid-liquid separator that separates solid particles from a fluid in which the solid particles are dispersed includes: a flow channel part where a linear flow channel into which the fluid is introduced is formed; and an ultrasonic vibrator as a secondary flow generation mechanism that generates a secondary flow in a cross-section direction in the fluid flowing on an upstream side of the flow channel. The flow channel includes a rectangular cross section defined by a flow channel width and a flow channel height perpendicular to the flow channel width. An aspect ratio of the cross section at least on a downstream side from the secondary flow generation mechanism in the flow channel is in a range from 10 to 100, the aspect ratio being expressed by a ratio of the flow channel width to the flow channel height.

Disclosed herein is a method comprising discharging a slurry from a vessel to a conduit; where the slurry comprises a liquid and a composition comprising at least two materials having different densities-a first material having a higher density and a second material having a lower density than that of the first material; creating a surge in velocity in slurry flow as it is transported through the conduit; separating the first material from the second material; where the first material is disposed on an inner surface of the conduit and where the second material flows through the conduit to a container; and removing the first material from the inner surface of the conduit.

The invention provides a novel filtration apparatus for the selective separation of metals from a mixture thereof. The invention also provides a method for the separation and isolation of metals from a sample using electrochemical precipitation.

The invention provides a novel filtration apparatus for the selective separation of metals from a mixture thereof. The invention also provides a method for the separation and isolation of metals from a sample using electrochemical precipitation.

In a method for separating low density particles from feed slurries, a bubbly mixture is formed in a downcomer and issues into a mid region in a chamber. An inverted reflux classifier is formed by parallel inclined plates below the mid region allowing for efficient separation of low density particles which rise up to form a densely packed foam in the top of the chamber, and denser particles which fall downwardly to an outlet.