Abstract: A mineral separating gold cube concentrator presents at least two modular portable stacking trays defining alternating inclined surfaces over which a continuing supply of water flows. A first tray provides an inclined smooth surface with controlled water flow to the incline which imparts fluidity allowing the aggregate to move downward and form a slurry that separates the aggregates into lightest first, heaviest last. A second tray is a collection tray is below the first tray and defines a G force separator, forcing all materials under the gate into vertical column within the turbulent water, the column descending upon the vortex mat upon the second tray, forcing the lighter materials within the aggregate to advance ahead of the heavier material. Any material not captured by the vortex mat travels to the end of the matting and is either expelled or subsequently transferred into another collection tray through another G force separator.

Abstract: The invention concerns a method for making a container (1) comprising two or more compartments, said method including the following steps: a first step of heat sealing (S1) performed between two sheets (111, 112) so as to form the periphery of the container and performed at a temperature such that said seal (S1) is resistant to a predetermined stress, while providing filling orifices (12), a second step of heat sealing (S2) performed to form at least one separation between the compartments (13) and performed at a second temperature lower than said first temperature and such that said seal (S2) is breakable by said stress, a third step of filling said compartments (13). The invention is characterized in that after said first sealing step, the two sealed sheets (111, 112) are arranged in a mold (2, 2?) whose shape they match under the pressure of a gas.

Abstract: A process for the production of alumina trihydrate by alkaline digestion of bauxite using the Bayer process in which aluminate liquor and insoluble residues are separated using a solid/liquid separation device (E; W2; DC) characterised in that the said slurry (21a; 41; 230?) is at least partially passed through a hydrocyclone (H1; H21; H22; H3) to improve and accelerate the separation of the sodium aluminate liquor from the insoluble residues in the slurry (21a; 41; 230?) containing the said liquor and the said residues and that supplies or is derived from the said liquid-solid separation device. In a first embodiment, at least one hydrocyclone is used at the upstream side of the settler-thickener, as clarifier of the pregnant liquor. In a second embodiment, at least one hydrocyclone is used as a thickener of insoluble residue mud. In a third embodiment, a hydrocyclone is used in combination with the causticisation settler.

Abstract: An aggregate material separating device includes a frame with a shaker mechanism. A trough is disposed on the frame and coupled to the shaker mechanism by a shaker spring. A hopper is disposed at an end of the trough and can receive a load of aggregate material. A hopper wash line is disposed adjacent the loading hopper to irrigate the aggregate material in the hopper forming a slurry. A brush and a backwash spigot form a standing wave in the trough to slow slurry movement from through the trough in order to provide additional settling time for the slurry. A mineral separation bed is disposed along a bottom and side of the trough. The mineral separation bed has a plurality of substantially longitudinal riffles that can be sized, shaped and oriented to capture minerals of a predetermined specific gravity from the slurry as the shaker shakes the trough.

Abstract: A washing liquid distribution system includes a spiral separator having a plurality of flights, each flight including at least one receiving cup for distributing liquid onto the flight. A directional outlet nozzle is mounted in cup for providing a horizontal outlet stream of a liquid. The nozzle is both rotatably and releasably mounted in a recess at the bottom of the cup. One or more outlet openings in a variety of geometric shapes to provide the desired outlet stream of wash liquid.

Abstract: A method of enhancing the magnetic separation of ores is disclosed in which a sulfonated polymeric dispersant is added to an ore slurry just prior to or during the magnetic separation operation. The sulfonated polymeric additive inhibits heterogeneous flocculation during the magnetic separation operation.

Abstract: A system for delivering the same or differing controllable amounts of washing liquid to several flights of a spiral separator including a housing, a plurality of spaced members having a respective generally vertical passage communicating with fluid in the housing and permitting fluid to flow therethrough. A plurality of fluid passageways respectively communicate with the members to provide the same or differing amounts of liquid to each of the flights. The distributor housing may include a central liquid receiving chamber, a plurality of spaced compartments located in proximity with the chamber, a plurality of passages through which fluid flows into fluid passageways respectively coupled to the compartments, a single flow controller rotatable therein to expose different portions of said passages at every rotation thereby varying the liquid flow to each compartment.

Abstract: A system for separating construction debris into low density debris and high density debris. The construction debris is delivered into a rotating drum having front and rear discharge openings. The lower portion of the drum is filled with water, and the debris is deposited onto the water, with the low density debris floating at the surface and the high density debris descending to the bottom of the drum. A plurality of high velocity water jets are positioned forwardly of the debris receiving location to create a turbulent high velocity water flow at an upper zone of the water in the drum to move the wood and other low density material toward a rear converging passageway that leads into the rear discharge opening. The higher density material is carried by a scroll type conveyor forwardly in the drum to a forward discharge location where rotating paddles lift the high density debris upwardly and thence move it into the front discharge opening.

Abstract: Disclosed herein is a method and system for sorting recycled solid waste materials, such as plastics, by a liquid-fluidized bed classifier (LFBC) technique. The application of a LFBC to the separation of plastics, and in particular plastic particles, is shown to be advantageous for a number of reasons. Firstly, the primary fluidization medium, i.e., water, is present in large quantities during conventional chopping, washing, and flotation operations that are performed during plastics recycling operations. Secondly, the natural density distribution of the major types of recycled plastics favors segregation by density in water, i.e., the "lighter-than-water" polyolefins, polypropylene (PP) and polyethylene (PE) from the "heavier-than-water" polystyrene (PS) PVC and PET plastics. The latter types of plastics have been found to separate spatially in an upflow LFBC, while the "lighter-than-water" plastics can be collected at the top of the column, thereby combining flotation and classification in a single step.

Abstract: An improved jig screen for a centrifugal jig includes a recovery zone and a stratification zone adjacent to one another. The stratification zone is constructed to prohibit outward radial passage of slurry particles while permitting fluid pulsations to be imparted to the slurry during jig screen rotation. The stratification zone axially leads to the recovery zone. The recovery zone has openings permitting passage of particles in the slurry and through which fluid pulsations are directed to the slurry during jig screen rotation. The combination of applying centrifugal force and fluid pulsations to a pre-stratified slurry more effectively separates the heavy particles passing through the recovery zone of the jig screen from the lightweight particles discharged at its exit end.

Abstract: The apparatus includes a funnel, connected to a section of clear hose. The clear hose has installed in line, 3 valves, for regulating water flow to the funnel for the process of separating gold from gold bearing soil.

Abstract: A sluicing operation for entertainment comprises a two portion unit, having storage facilities and sluicing area with at least one trough at approximately a 2.degree. angle. The storage facilities have a water/ore separation unit, precious material holding bin with measuring device, conveyor and ore weighing device. The conveyor transports the precious material and ore to a holding unit where it is dispensed. Pipes circulate the water or ore/water combination. The bottom of the trough can be mesh, the ore filtering through onto a second conveyor where it is carried to an ore receiving area. A flared side sluicing pan with a perforated base separates the highly polished ore and precious material. A controlled artificial river forms a permanent sluicing operation using passive filtration dams with controlled inlet ports. The water is filtered through filtration matting before entering the inlet ports. The riverbed is filled with gemstone and gold enriched sand and gravel.

Abstract: A particle concentrator and method of operation are disclosed wherein the concentrator includes a concentrator deck, preferably having an inverted frustoconical configuration with substantial portions of the deck being vertically inclined, an eccentric drive for producing rotary oscillating movement of the deck with low density and high density particle outlets respectively formed on an axially central portion of the deck and a peripheral portion of the deck. Riffle elements are angularly formed on the deck to facilitate particle separation with a mechanical stop limiting travel of the deck in a direction selected for propelling the higher density particles along the riffle elements toward the high density outlet. The concentrator may be operated either dry or submerged under standing liquid, with annular inclination of the deck, angular pitch of the riffle elements and height of the riffle elements on the concentrator deck being selected to facilitate classification and separation of the particles.

Abstract: A centrifugal jig screen with a rotating hutch is supplied with inwardly directed pulses by overlapping fluid supply nozzles and pulse blocks coaxially arranged about the jig axis. Fluid not directed to the hutch interior in sharply defined pulses is diverted into a surrounding shroud, permitting the incoming fluid flow to be substantially uninterrupted during jig operation. Wedge surfaces about the hutch prevent buildup of separated materials as the are discharged from the hutch.

Abstract: A pulsator for enriching, particularly, hard coal has mounted in a pulsating compartment a hoisting wheel and a bracket both mounted on a drive shaft, or a ratchet wheel mounted on a drive shaft which runs in bearings above the liquid level of a working trough. The pulsating compartment is of cylindrical shape and is connected to working trough along its longer side and separated from the working trough with a wall. The pulsating compartment consists of an outer wall to which is welded a bottom wall shaped as an arc and connected via a vertical wall to an oblique wall of the working trough. The bottom wall is provided at its lowest point with a grate encased with a pulp outlet stub pipe. The hoisting wheel consists of a side wall connected with an outer screen which is connected in turn to an outer ring along the periphery of the outer screen.

Abstract: Apparatus is provided to separate heavier metal particles from lighter particles gangue in a fluidic medium by gravity and fluid flow. A vertical container provides a lower fluid input chamber that communicates through a medial structure providing a plate defining a plurality of valve ports, a screen, and a plate defining a plurality of holes to an upper chamber carrying particulate material to be beneficiated. Pressurized water flows upwardly through the medial structure to separate more dense metal bearing particles in the medial structure and gangue exits from a central orifice defined in the medial portion of the separating structure. The apparatus uses small amounts of water which may be recycled. The beneficiator is unusually efficient in recovering particulate gold from alluvial sands.

Abstract: An electronic control method and apparatus for controlling the sloughing strokes in sloughing machines for coal and other minerals, has a stroke frequency generator which supplies recurrent signal codes to parallel-connected inlet and outlet stroke generators. Power amplifiers are connected to the stroke generators for amplifying command pulses therefrom, the pulses being supplied to inlet and outlet valves of the machine. A signal code is supplied from the stroke frequency generator through a divisor in a freely selectable clock sequence to the outlet stroke generator or alternatively the divisor releases the command pulse from the outlet stroke generator to the outlet valve in a freely selectable clock sequence.

Abstract: Separating elements (14) arranged about a central shaft (1a) rotate in common about the main axis (A) and individually about their longitudinal axes (B). A centrifugal distributor (6) distributes fine-grain mineral mixture mixed with fluid uniformly to the separating elements (14). In each separating element (14) the partial material flow (2a) is set in rotation about the longitudinal axis (B) by entrainment vanes (18) arranged in a first separating element section (15a) and the heavy fraction is centrifuged on to the separator wall (16a). In the second section (15b), formed as conical tubular worm conveyor, which contains no entrainment vanes, the heavy fraction is transported to the collecting chamber (21) and discharged through first discharge openings (22), the fine-grain mineral mixture being fluidized in pulsation on the separating wall (16b) by the combined rotating movements and the heavy fraction being concentrated.

Abstract: A centrifugal separator has a rotating tub with annular dams to trap the heavier components of the slurry fed into the tub through a centrally located feed tube. The latter rotates at a speed slightly different from that of the tub and supports radially extending spokes that have depending tines provided with lower nozzle defining ends in the annular spaces between the dams. Water under pressure emanates from these nozzles. An alternative tub configuration has annular water manifolds inside these annular spaces to provide water under pressure to nozzles in the tub itself for supplementing the action of the nozzles in the depending tines.

Abstract: A portable sluice box for classification of mineral particulate from detritus or placer deposits containing the same is comprised of an infeed table including upstanding sidewalls and a bottom wall for receiving and confining a charge of mineral-containing deposits for fluid compelled movement along a path lying in a material handling plane generally coincident with the bottom wall of the table; a classification table member, including upstanding sidewalls and a foraminous separation plate having downwardly depending, opposed marginal skirts for proximal engagement with the sidewalls of the separation table interiorly thereof, the separation plate also lying within the material handling plane; a plurality of riffles disposed transversely in a laterally and longitudinally extending spaced array between the skirts, defining a series of upper flow channels intermediate the separation plate and the top edge of the riffles and a lower, mat channel intermediate the bottom wall of the classification table and the bo

Abstract: A centrifugal jig to beneficiate ore by separating a heavier particulate fraction from a lighter particulate pulp. The jig provides a rotor with a vertical cylindrical jig screen rotating in a fluid filled hutch to support a vertical jigging bed. The jigging bed is pulsed sequentially as it is rotated past plural spaced pulsing elements positioned in the hutch externally of the jigging screen. Pulsing may be by pressurized air in the form of fine bubbles, by pressurized fluid or a combination of both. Pulp material is fed at the bottom of the jigging screen to move upwardly thereacross with the lighter gangue material exiting above the screen for exhaustion and the heavier mineral bearing fraction exiting through the screen for subsequent recovery from the bottom periphery of the hutch area. The jig may be used as a bedded centrifuge or in the fashion of a traditional jig especially as when provided with ragging.

Abstract: A method of and apparatus for feeding and discharging air for pneumatic jigs, includes feeding and discharging pressure air to and from air chambers, which are opened at their respective lower ends, and which are formed in water-filled tanks, to vertically vibrate water in the water tanks, and separate a pulverulent body on the water. The air feeding and discharging steps are carried out repeatedly, and with having overlapping periods. The apparatus comprises an outer cylindrical casing, and an inner casing provided rotatably in the outer casing, the outer casing being provided in a circumferential wall thereof with a communication port communicated with air pipes opened into the air chambers. A plurality of air ports communicate with an air feeding unit which is capable of feeding air of a plurality of different pressures to the air chambers, and a discharge port is provided.

Abstract: A wet jigging mechanism for handling coal or other minerals including a mineral containing tank, a pulsed air chamber opening downwardly into the tank, a compressed air source with a conduit and a vent conduit with valves in the conduit, the valves including pivotal butterfly valves on a shaft with a swing flap operator operated by the compressed air to move the butterfly valve and the swing wing engaging a variable positioned rubber stop damper at the open position of the butterfly valve, and a rubber seat for the butterfly valve in closed position acting as a damper.

Abstract: Gold flakes and small nuggets are separated from heavy sand by fluidizing the mixture with an upwardly flowing water column having a very uniform velocity across its section. The upwardly flowing water column has sufficient flow to fluidize the suspended material but not enough to carry the heavy sand over the top of the column. Heavy sand is withdrawn from the upper portion of the fluidized mixture to leave the gold below the withdrawal point.

Abstract: An expansible chamber is expanded to create a partial vacuum within the chamber. Following expansion, a burst of fluid pressure, attended by fluid flow and an acoustical wave, is introduced into the chamber. Simultaneously, the chamber is forcibly contracted. This transducer produces a square acoustical wave. When the transducer is incorporated into the hutch of a mining jig, it results in the pulling of agglomerations of minute particles down out of the gangue and into the hutch chamber. An annular valve member is movable axially towards and away from a valve seat. The valve member includes a concave sealing surface which mates against a convex valve seat having a smaller radius of curvature. Sealing contact is made adjacent the high pressure side of the valve. A gap is created which widens from the zone of contact towards the low pressure side of the valve.

Abstract: A control apparatus for a rotary valve-driven jigging machine for processing coal or other minerals, particularly for a rotary valve-driven throughput jigging machine whose pulse chambers periodically are charged with compressed air in order to generate a pulse motion and are disposed under the jig screen, is characterized in that the level of the working air pressure in the pulse chambers is changed as a function of changes of the size of the stroke of the separating liquid. The change of the level of the working air pressure in the pulse chambers occurs by a controlled throttling of the outgoing air and/or of the incoming air.

Abstract: A sluice box apparatus for recovering heavy material, such as gold, comprises a fine recovery channel and a coarse recovery channel. The recovery channels have receiving ends, riffles and matting for collecting fines of the material. A hopper at the receiving end of the channels has a receiving end for aggregate, a discharge end adjacent the receiving ends of the channels, a bottom, an open top and water distributing means near the top and the discharge end for washing fines from the aggregate. A perforated plate extends substantially across the hopper near the discharge end. The plate is spaced-apart from the bottom. There is a coarse material discharge opening adjacent the coarse recovery channel for a flow of water and aggregate passing over the perforated plate to the coarse recovery channel and a fine material discharge opening between the bottom end and the perforated plate and adjacent the fine recovery channel.

Abstract: A hydraulic bean cleaner for removing rocks from beans has a hopper for gravity-feeding uncleaned beans down an inner cylindrical tube into a cylindrical separator tank. The inner tube has a bean discharge opening centered just above the bottom of the tank. An outer cylindrical tube concentrically surrounds the inner tube, providing an annular passageway therebetween and a water discharge opening surrounding the bean discharge opening. A first vibrator vibrates the tubes as a unit to help feed the beans down the inner tube. A second vibrator vibrates the hopper independently of the tubes to aid in feeding the beans to the inner tube. The beans drop into the bottom of the tank and water is expelled downwardly into the tank around them. The water entrains and fluidizes the beans, carrying them laterally away from the bean discharge opening and buoying them upwardly. The turbulent flow of water agitates the beans.

Abstract: An air valve for a wet settling machine includes a trapezoidal cross-section valve seat and a valve disk carried on a shaft. The shaft is directly actuated in alternate directions via an electromagnet surrounding the shaft and including a pair of oppositely poled magnetic sections.

Abstract: Apparatus and process for the beneficiation, or for the continuous hydraulic elutriation of particulate solids. The apparatus is characterized generally as an elongate vessel, with a width of V-shaped cross-section. The upper side of the vessel is provided with launders, or overflow weirs, suitably arranged in series along the two side walls of the vessel. An elongate upwardly faced compartment is provided at the bottom of the vessel by the converging side walls, and preferably it is compartmented. The vessel is provided at one end with a particulate solids inlet, and the opposite end with a particulate solids outlet; and means are provided at the bottom of the vessel for the introduction of liquid. Pumps are employed to withdraw overflow liquid from the launders, and inject same into the vessel bottom compartment, or compartments.

Abstract: A wet settling machine having a jig screen has the separating liquid mechanically pulsed and the energy of the pulsations is stored in and released from sealed air chambers which open downwardly into the settling liquid.

Abstract: A wet settling machine for processing mineral mixtures, particularly fine-grained coal and other minerals, has the separating liquid energized into a pulsating motion with a basic wave and an upper harmonic superimposed on the base wave. The harmonic wave may proceed longitudinally with respect to the base wave or transversely with respect to the base wave. The base wave is pneumatically generated and the harmonic wave is mechanically generated.

Abstract: A starting method for an electro-pneumatically actuated wet-settling machine, for the separation of mineral mixtures, particularly coal, into their constituent components, in which the separation of the mineral mixture takes place through the pulsation of a separating liquid which is energized and controlled by means of compressed air in pulsation chambers which have electrically controlled air inlet and outlet valves, and in which the initiation of the wet-settling process takes place after a standstill, at least partially automatically, particularly through an electrically or electronically operating automatic starter, which starts at least some settling machine apparatus and/or their components in a predetermined dependency upon one another.

Abstract: An electropneumatically actuated wet settling machine for the separation of mineral mixtures, having a separating liquid to carry out a pulsating movement set in motion by the introduction of compressed air into exciter chambers via inlet and outlet valves, is controlled so that the start of the pulsation movement of separating liquid from a rest condition takes place through a gradual filling of the excitation chambers with compressed air, at least partially automatically controlled, and in particular by an electrical automatic starting control.

Abstract: An automatic control for an electropneumatic wet settling machine, for the separation of mineral mixtures, in particular coal, through the pulsation of the separating liquid, provides that the separating liquid is energized and controlled by means of compressed air in pulsing chambers, and that measuring devices for measuring the movement of the separating liquid are provided to signal, advantageously on an analog basis, the movement of the separating liquid in order to control the introduction and exhaust of compresssed air from the pulsing chambers.

Abstract: A wash box for separating materials produced in, for example a mining operation, into fractions of different densities. The machine is divided vertically into compartments, including at least one stratification compartment and at least one reject compartment, the raw material being delivered onto the grid, the level of water in the compartments being higher than the grid. Vertical pulsations are applied to the water in the compartments, causing the water to travel through the perforations of the grid. The pulsations applied to the stratification compartment are effective to stratify the material on the grid, movement of the water through the wash-box tending to carry the lighter fraction from the wash-box while the pulsations applied to the reject compartment determine the rate at which the heavier fraction reject material falls from the grid plate into a reject extraction chamber adjacent to the reject compartment.

Abstract: An apparatus for cleaning coal of extraneous matter such as gravel and the like includes a stratifying and classifying oscillating screen submerged in a liquid confining tank wherein stratification is produced by motion of the oscillating screen. The screen bottom slopes downwardly and water flow is induced from either end of the screen to aid in the stratification. The coal which rises to the top is removed by several skimmers powered by a vacuum controlled materials handling pump.

Abstract: Simple, flow regulating tap-off means are provided in the bottom of a helical eluent supply conduit which is co-axial with a helical separator sluice in a gravitational separator. The tap-off means is an insert in the floor opening of the eluent conduit having an aperture in the insert and an inner lip at the top of the insert that does not extend above the floor of the eluent conduit. A portion of the inner lip is broken away to facilitate directing the eluent to flow through the aperture. Rotating the insert varies the amount of the broken away portion in contact with the downward flowing eluent which in turn regulates the amount of eluent flow through the aperture.

Abstract: A wash box for separating materials produced in, for example, a mining operation, into fractions of different densities. The machine is divided vertically into compartments, including at least one stratification compartment and at least one reject compartment, the raw material being delivered onto the grid, the level of water in the compartments being higher than the grid. Vertical pulsations are applied to the water in the compartments, causing the water to travel through the perforations of the grid, to stratify the material on the grid, while movement of the water through the wash box tends to carry the lighter fraction from the wash box.

Abstract: A riffled ore concentrating table of the reciprocating type is connected to a table support by ball bearings. The table support has one of its edges pivotably connected to one edge of a base member and the other of its edges supported by the other edge of the base member in a manner such that the elevation of one edge of the table may be adjusted with respect to the other edge of the table.

Abstract: A separator for mixed solid particulate materials such as gold or heavy minerals which are dispersed in a host material such as sand. A circular disc has a slanting surface with a plurality of riffles for catching the heavy materials. The riffles are defined by a plurality of annular baffles each having short radial walls projecting toward the center of the disc. A water turbine having off-center weights is used to vibrate the disc.

Abstract: Fractions of different densities contained in an ore or other solid material are separated by directing the solid material in a liquid suspension on to a surface of an endless belt, moving in the direction of its length and inclined transversely to its direction of motion, along a first part of the length of a higher portion of the belt and subjecting said moving surface of the belt to a shaking motion so that lighter fractions are separated from the material and flow off a lower side edge of the belt into a receptacle. Washing liquid is directed on to the moving surface from another part of the length of the higher portion of the belt that is downstream of the first part so that washing liquid flows transversely across the shaking, moving surface to separate middling fractions from the material and carry them off the lower side edge of the belt into a second receptacle.

Abstract: A method and apparatus for the preparation of mineral mixtures, particularly of rough washed coal, on a jig which is controlled by compressed air in which the separating liquid, with the aid of control valves arranged in the supply conduits for air and/or separating liquid, is moved periodically up and down through the openings in the settling material carrier, wherein the pulsating movement of the separating liquid is effected with the aid of an electronic valve impulse control of the compressed air and/or the quantity of separating liquid conveyed to the settling tank.

Abstract: A Baum Jig for gravitational enrichment of minerals, particularly hard co in which a screen deck is transversely located to the axis of the jig. Air chambers are made of plates as cut-outs of a cylindrical surface. The axes of symmetry are deflected from the perpendicular by an angle of 5.degree. to 15.degree. in the direction of the mineral to be enriched. The chambers are provided with asymmetric guide vanes adjustable in the horizontal direction. The side walls of a water cistern possess at the height of the screen decks, horizontal off-sets outside the cistern. Spring-loaded protection plates are provided in the off-set supports. The lower edge of one wall of each chamber is shaped as a conduit of back water provided from the bottom with a deflectable arched diaphragm.

Abstract: A Process and Apparatus for use in concentrating an aggregate mixture of particles, such as minerals and non-minerals wherein the mixture is introduced onto an inclined endless conveyor adjacent one edge of the incline and is advanced along or parallel to the incline while water is flowed across the inclined surface and the aggregate mixture during the advancement causing the lighter particles to flow with the water down and off of the inclined conveyor while the heavier particles cling to and are advanced with the conveyor surface to a collection area. The endless conveyor includes a plurality of slightly raised ribs on the upper surface which define recesses therebetween for catching and holding the heavier particles during advancement of the conveyor. The raised ribs can be formed into a number of various patterns. The endless conveyor also includes a plurality of horizontally spaced, downwardly projecting tits which form a reduced friction support surface and conveyor engagement drive means.

Abstract: Dewatering apparatus is provided, for use in the treatment of particulate material in water, particularly suspensions of sand in water. The apparatus is also provided with means for classifying sand or like particulate material by size. The apparatus employs a sloped trough extending upwardy from a well having sand and water therein, and with a longitudinally moveable rake being provided, with a particularly novel mechanized raking motion, preferably hydraulically operated. The classifying is done by varying the inflow and consequently the overflow of water through the apparatus, varying the water flow from spray pipes extending along side of the discharge trough, or by speeding up the operation of the apparatus.

Abstract: A dredge unit having a buoyant support carrying a sluice box suspended beneath, a water suction system connected to an outlet end on the box and a suction hose operatively connected to an inlet end thereof. The water suction system operates to draw water and material through the suction hose and into the sluice box where material of relatively high specific gravity is contained while the remainder and the water is discharged from the system.