Abstract: A fine flaky copper powder having an average major axis diameter of 4 to 10 &mgr;m and a flakiness of 2 to 20, has a bulk density of 2 to 4 g/cm3 and a BET specific surface area of 0.4 to 1.5 m2/g; A process for producing the copper powder includes introducing a copper slurry into a medium type agitation mill and flattening the powder.

Abstract: The present invention relates to a method of reducing particle size by the use of a supercritical fluid, generally carbon dioxide. The material is swollen by the supercritical carbon dioxide at a high pressure. After the material has been allowed to swell under a high pressure, the pressure is rapidly dropped. When the external pressure is rapidly dropped, the material explodes as the supercritical gas absorbed into the material rapidly expands outward.

Abstract: The present invention provides a method of synthesizing hydroxy apatite comprising the steps of preparing a mixed material slurry by dispersing calcium hydroxide (Ca(OH)2) powder into a phosphoric acid (H3PO4) solution; conducting a mechanochemical milling treatment in which shearing force and compressive force based on a centrifugal force of a mechanical rotating body are imparted to the mixed material slurry, and reacting the calcium hydrate component with the phosphoric acid component under normal temperature and pressure thereby to prepare hydroxy apatite (HAp) powder having fine crystals. According to the structure described above, there can be provided a method of synthesizing hydroxy apatite having fine and uniform particle size which can be directly synthesized under normal temperature and pressure in a short time through simple and single process.

Abstract: Ground calcium carbonate compositions having narrow particle size distributions and a method for producing the compositions. The method involves forming a substantially dispersant-free calcium carbonate suspension, wet-grinding the suspension, and aging the suspension. The method does not require the use of classification equipment and the aging process does not require heating.

Abstract: The invention provides a process for the fine division of pigments which comprises spraying a coarsely crystalline crude pigment and/or a poorly dispersible prepigment in suspension form through nozzles to a point of conjoint collision in a reactor chamber enclosed by a housing in a microjet reactor, a gas or an evaporating liquid being passed into the reactor chamber through an opening in the housing for the purpose of maintaining a gas atmosphere in the reactor chamber, and the resulting pigment suspension and the gas or the evaporated liquid being removed from the reactor through a further opening in the housing by means of overpressure on the gas entry side or underpressure on the product and gas exit side.

Abstract: A pulper in a stock preparation system includes a housing with a fiber inlet, at least one water inlet, at least one outlet and an inner chamber. A plurality of rotatable augers extend into the inner chamber.

Abstract: The invention provides a process for the fine division of pigments which comprises dissolving coarsely crystalline crude pigments in a solvent and precipitating them with a liquid precipitation medium by spraying the pigment solution and the precipitation medium through nozzles to a point of conjoint collision in a reactor chamber enclosed by a housing in a microjet reactor, a gas or an evaporating liquid being passed into the reactor chamber through an opening in the housing for the purpose of maintaining a gas atmosphere in the reactor chamber, and the resulting pigment suspension and the gas or the evaporated liquid being removed from the reactor through a further opening in the housing by means of overpressure on the gas entry side or underpressure on the product and gas exit side.

Abstract: An autogenous grinding mill (10) includes a support casting (12) and a drive motor (14) which rotates a drum (18) defining a generally cylindrical grinding chamber. The other end of the chamber has a discharge opening (22) through which a stationary shaft (24) passes. One or more shear-inducing members (26, 26′) are affixed to the shaft (24). A continuous feed of flowable particulate material, for example a slurry or power, is introduced to the rotating grinding chamber via feed passage (28) passing trough the stationary shaft (24). The mill also includes means for introducing a fluid into a layer of material being ground to contact that material. This means can be the same passage (28) used for the feed material or might be a separate passage.

Abstract: The present invention provides a new and improved method of using a volatile liquid color system to prepare colorant-coated polymeric resin powders for use in rotational molding. The method according to the present invention includes simultaneously feeding polymeric resin pellets or granules and a volatile liquid color system into a grinding mill to produce a colorant-coated polymeric resin powder for use in rotational molding. During grinding, the volatile liquid color system coats the surface of the freshly ground polymeric resin powder and dries, leaving no residues that will volatilize during rotational molding or exude from the surface of rotationally molded parts during molding. The method of the present invention eliminates the need for additional processing steps after resin grinding, such as distributive mixing and drying. Rotational molded articles produced according to the present invention exhibit excellent color uniformity.

Abstract: The present invention relates to a method of reducing particle size by the use of a supercritical fluid, generally carbon dioxide. The material is swollen by the supercritical carbon dioxide at a high pressure. After the material has been allowed to swell under a high pressure, the pressure is rapidly dropped. When the external pressure is rapidly dropped, the material explodes as the supercritical gas absorbed into the material rapidly expands outward.

Abstract: A process for producing a colored wood product, comprising the steps of grinding wood in a mill until a wood compact is formed, sieving the wood compact, spraying the sieved wood compact with an aqueous solution of colorant, immersing the wood compact in a bath of aqueous solution of colorant while simultaneously moving the wood compact with a multiplicity of counterrotating augers, and then removing the wood compact from said bath. The mill preferably contains a rotor with several cutters disposed about its periphery.

Abstract: The present invention provides a process for preparing a raw material powder for producing a sintered body of aluminum titanate comprising: pulverizing a mixture containing: (1) 100 parts by weight of aluminum titanate crystals pulverized until a maximum grain size of 30 to 50 &mgr;m is attained; and (2) 2 to 6 parts by weight of spinel crystals obtained by heating a mixture containing MgO and Al2O3 at 1250° C. to 1290° a molar ratio of MgO to Al2O3 being 1:0.95 to 1:1.05, said pulverizing being conducted by wet grinding process with a ball mill or cylinder mill.

Abstract: The present invention relates to an apparatus and method for separating and processing solid waste, often but not necessarily from municipalities (and so will be generically referred to herein as municipal solid waste or “MSW”), into useful products, and for reducing biohazards and putrid odors derived from MSW. The MSW is loaded into an elongated, generally cylindrically shaped rotating pressure vessel and is subjected to heat and pressure by the application of steam in specified amounts to break down the organic portion of the MSW into a cellulose feedstock, or a de-manufactured paper product, of uniform particle size and density. This product is then easily separable from other constituents of MSW, such as glass, aluminum and other metals, and plastics. The recyclables are recovered and sold in the market. The waste water from the process is reduced by processing through a water vamping apparatus.

Abstract: Process for production of three-dimensional objects by stereolithography in which a laser hardens particular areas of constantly succeeding layers of resin fluid. Prior to or during laser light action, the particles, which define physical or mechanical qualities of the object-to-be-produced, will be added into, and/or alternatively, will be produced within the resin fluid, leading to a resin-fluid-particle-mixture. The particles are integrated into the resin and/or compound with resin and/or other particles by means of laser light action or ultrasonic mixing.

Abstract: A size reduction apparatus and process for reducing the size of a heterogeneous or homogeneous article or articles using variable and interchangeable interior parts for varying article output size and an air handling system for introducing air and/or fluid into the process of size-reduction. The components of a heterogeneous article are separated and used to aid in the size-reduction process.

Abstract: A process for producing a colored wood product, comprising the steps of grinding wood in a mill until a wood compact is formed, sieving the wood compact, spraying the sieved wood compact with an aqueous solution of colorant, immersing the wood compact in a bath of aqueous solution of colorant while simultaneously moving the wood compact with a multiplicity of counterrotating augers, and then removing the wood compact from said bath.

Abstract: A method of accelerated remediation or bioremediation of contaminated material using an apparatus comprising means for generating a treated contaminated material entraining air stream at a velocity sufficient for entraining the contaminated material therein. The contaminated material is entrained in the air stream and is then microenfractionated using the apparatus to form a microenfractionated contaminated material. Finally, the microenfractionated contaminated material is treated with at least one chemical amendment and/or one biological amendment by discharging the chemical amendment and/or one biological amendment from the apparatus thereby facilitating the accelerated remediation or bioremediation. The chemical amendment can comprise either a chemical oxidizing agent, a chelating agent, or a metallic reducing agent. The preferred metallic reducing agents are zero valent iron, zero valent zinc, zero valent tin, zero valent manganese and zero valent aluminum.

Abstract: A device for sorting raw, pre-treated or recycled bulk materials, which are comprised of individual components to be sorted, wherein the classification of the parts to be sorted occurs along empirically determined classification parameters and the material which is sorted is removed, the device including a conveyance device for supplying the bulk material, a conditioning device for wetting the bulk material, a break-down device for breaking down the bulk material into individual parts to be sorted, a sensor device for sensing the classification-relevant characteristics of the components to be sorted and for production of measurement data, which includes at least one camera, which is connected to a device for evaluation of electronically measured values with at least one micro computer for classification of the components to be sorted and for achievement of a control signal by means of a control unit, wherein the camera is associated with at least one even diffused light emitting light source.

Abstract: A system for producing a suitable fuel from waste material including a dispersion tank in which a rotating impeller is positioned in the bottom of such tank in close spaced relationship above a stationary plate and the facing surfaces of the impeller and the plate include shear blocks which intermesh to grind solid materials in the tank and disperse the solid materials in a blend stock making a suitable fuel. A cylinder is connected to raise and lower the impeller to control the spacing between the impeller and the plate and thus control the spacing between the shear blocks to control the fineness of the grinding of the waste material. Means is provided for discharging metal from the dispersion tank and means is provided for circulating liquid from the dispersion tank to an accumulation tank and for recirculating the liquid from the accumulation tank to the dispersion tank.

Abstract: A system for reclaiming carpet components such as yarn, tufting primary, binder, and secondary backing wherein the carpet is sprayed with a high velocity water spray so as to disjoint the components from one another, and thereafter, separating the secondary backing from the yarn and tufting primary. Desirably, water is removed from the disjointed carpet after spraying the carpet with high pressure water spray. This system is useful for reclaiming components of broadloom carpet and carpet tiles and cleanly and efficiently separates tie components of carpet.

Abstract: A method and apparatus is provided for the processing of polypropylene fiber from polypropylene twine. The material may be produced from feedstock after its first instance of usage. The feedstock may have residual contamination resultant from its first instance of usage. The method is provided to collect feedstock in skeins, sever the skeins into bundles, wash, disinfect and pH neutralize the surface of the feedstock, cut to length and reduce the feedstock to a fibrous clean, dry state suitable for use as a reinforcement or additive to composite material.

Abstract: A cylindrical chamber has a drive shaft rotatably mounted therein and extending along substantially the entire longitudinal extent thereof. This drive shaft is rotatably driven by a motor preferably at a speed of about 3600 rpm. Solid particles to be comminuted which may be of coal, limestone/dolomite, or hydrated lime are fed into the chamber. Pressurized air is fed into the bottom of the chamber. Uplifting pressure for driving the air and particles upwardly in the chamber may be provided by pressurized gas in conjunction with a stationary velocity head. The upwardly driven particles are first driven through a plurality of rotors which are driven by the shaft and provide a centrifugal force which comminutes the particles. The particles are then driven through a plurality of semi-permeable screens which are rotatably driven by the shaft and further comminute the particles to a micronized state. To lower NO.sub.x and SO.sub.

Abstract: Microparticles including an organic coating covalently bound to an inorganic substrate are produced in one step by grinding the substrate while immersed in a reactive coating agent. Preferably, a silicon substrate is ground in the presence of an alkene to generate alkyl-coated silicon particles. The particle coatings are robustly attached to the particle cores through Si--C bonds. Various solids such as semiconductors can be used as substrates. The coatings can include various organic radicals, halogen atoms, or hydrogen. The particles can be used as stationary phases for chromatography, as substrates for biological assays, as polymer additives, or as catalyst supports.

Abstract: In a process for granulating and comminuting molten material, the slag melt is acted upon by compressed water and discharged together with the vapour formed. The liquid slag is introduced into a granulation chamber in a free flowing jet while directing compressed water jets against the slag jet, whereupon the solidified and granulated slag is conducted through a pneumatic conveyor duct and a distributor along with the vapour formed. The partial streams leaving the distributor, via conically tapering nozzles are transferred into a grinding space exhibiting a lower pressure than the granulation space and from which the comminuted and solidified material is drawn off.

Abstract: A method for grinding silicon metalloid comprising grinding silicon metalloid in the presence of an effective amount of a grinding aid selected from the group consisting of carboxylic acids comprising at least 8 carbon atoms, alkali metal salts of carboxylic acids comprising at least 8 carbon atoms, and polydiorganosiloxanes.

Abstract: Molten matte or slag is water granulated by feeding molten matte or slag through a launder to a granulator tank. The tank includes sloping walls and is equipped with adjustable overflow weirs and one or more of spray nozzles. These nozzles are positioned such that the water that they emit impacts on substantially all of the molten matte or slag that is fed to the granulator tank. The granulation tank is optionally coated with a polymeric material to reduce the potential for phreatic explosions. The granulator is also optionally equipped with a gas offtake which can be connected directly to a quench tower which in turn can be connected to an induced ventilation system.

Abstract: A particulating apparatus for liquid filled plastic containers in preparation for recycling produced plastic particulate. The particulating apparatus includes a container hopper for accepting a supply of plastic containers to be processed by the particulating apparatus wherein at least a portion of the containers are partially liquid filled. There is a transport for conveying the supply of plastic containers from the hopper to a pulverizer. The pulverizer has a pulverizing chamber within which a pulverizing means is housed for reducing the plastic containers to plastic particulate. The chamber includes means for draining liquid held within the containers to a liquid collector. A conveyor means is provided for transporting plastic particulate from the pulverizer to a collection bin where the particulate is retained for further processing or disposal. The conveyor means is inclined at least partially vertically upwardly from horizontal to permit drainage of additional liquid from the particulate.

Abstract: A disc refiner for thermo-mechanical pulping of wood chips or other fiber source for papermaking has annular refiner discs with a plurality of axially protruding radially extending curved refiner bars. Curved bars in the refiner zone should resist erosion and corrosion. Each disc has a region of bars which curve in the direction of rotation, and a region which curves away from the direction of rotation. Two identical refiner discs are mounted to rotate with respect to one another. Because of the bar curvature, processed stock experiences different angles of bar intersection as the pulp progresses from the inside of the refiner plate to the outside of the refiner plate, yielding a reduced hit on the pulp where opposed refiner bars curve in opposite directions. Where refiner bars on opposed plates curve in a like direction as they pass over one another there is a hold back action on the stock in that region.

Abstract: Deaggregated highly disperse silicic acid, in which the average particle size is less than 100 nm, preferably less than 50 nm, is prepared by extremely high mechanical stress. The deaggregated silicic acid is employed as a filler in silicone rubber mixtures.

Abstract: Metallurgical slag is expanded to produce a lightweight solid by forming a stream of molten liquid slag of controlled rate of flow and mixing the stream of slag with a controlled quantity of water and flowing the interacting mixture of slag and water into a receptacle. The interaction between slag and water is allowed to proceed for a predetermined period of time to form an expanded solid without the addition of any additional cooling water which would otherwise quench the material and vitrify it. In the receptacle, a vaned rotor operates to segment the interacting mixture of slag and water and project the segmented mixture through the air for collection into a heap.

Abstract: A trash disposal system for a building which facilitates the process of disposing of trash created within that building. The system includes a chute having an inlet within the building which routes the trash to one or more comminutors, such as grinders, arranged in series. The particles output from the comminutors are reduced in size and pass into a collection vessel installed underground external to the building. An agitator within the collection vessel mixes the trash particles introduced therein and promotes dissolution of the trash particles into water within the collection vessel. The water within the collection vessel, and the trash particles dissolved in that water, are either pumped or flow by gravity from the collection vessel to either a sewer lateral or a drain field for distribution. A method of disposing of trash is also disclosed.

Abstract: A dispersion method for uniformly dispersing solid or liquid fine particles in a solvent utilizes a supercritical fluid. A dispersoid of a solid, a liquid or the like is mixed with a solvent, and the resulting mixture is fed to a supercritical vessel. A supercritical solvent is then fed to the supercritical vessel and heated and compressed to a level higher than the critical temperature and critical pressure thereof to convert it to a supercritical fluid. The supercritical fluid and mixture of dispersoid and solvent are mixed together to form a supercritical mixture, which is released to atmospheric pressure in an explosion-crashing tank and subjected to collision within the explosion-crashing tank to efficiently disperse the dispersoid in the solvent.

Abstract: Methods and means for grinding materials to fine powders in a media mill in which the materials are ground while immersed in a liquid. In the preferred embodiments, the liquid is a gas at room temperatures and pressures, the materials are resin mixtures and the fine powders are predominantly in a size range of from about 10 to about 40 micrometers. Other benefits may be achieved if the gas is in a supercritical state.

Abstract: A method of solid insulator destruction comprising the steps of placing electrodes on a surface of a solid insulator, covering an area of the surface the solid insulator proximate the electrodes with liquid having greater electrical insulative properties against pulse voltage than the solid insulator; and applying a pulse voltage across said electrodes having a rise time to breakdown of the solid insulator of about t where t=2.times.10.sup.-6 .times.S.sup.0.3 (sec) and S (cm) is the distance between the electrodes. The solid insulator material includes at least one of rock, permafrost, ice and artificial solids including concrete, ceramics, and plastics.

Abstract: This invention relates to a method of using an apparatus is provided for the accelerated remediation of treated contaminated material. The material is treated with chemical amendments for facilitating accelerated remediation thereof. The apparatus comprises means for generating a treated contaminated material entraining air stream at a predetermined velocity for entraining the treated contaminate material therein for micro-enfractionating the treated contaminated material. In this way, accelerated remediation is facilitated. In another form of the invention, a method of accelerated remediation of treated contaminated material is provided.

Abstract: A process is dislcosed for recovering chips and fibers from residues of ter-derived materials, old pieces of furniture, production residues, water and other timber-containing materials glued with urea-formaldehyde binders or other binders capable of being hydrolysed or chemically disintegrated by disintegrating the timber-derived materials at a high temperature. In a first step of the process, the residues of timber-derived materials are impregnated with an impregnating solution and previously swollen until they have absorbed at least 50% of their own weight of impregnating solution. In a second step, the thus impregnated residues of timber-derived materials are heated up to 80.degree. C. to 120.degree. C. The thus disintegrated residues of timber-derived materials are then sorted by sieving and/or wind screening. The residues of timber-derived material have edges of at least 10 to 20 cm length.

Abstract: A clean refractory metal sponge fines product is made from refractory metal sponge fines free of refractory metal oxides, carbides, nitrides and binary iron alloys; silicon carbide, oils, greases and organic compounds; salt; dust; dirt; pieces of iron, iron alloy and tungsten carbide; and light contaminants. The sponge fines are vigorously washed and rinsed with a displacement wash to remove the bulk of the wash fluid and subject to a counter-current wash to yield clean refractory metal sponge fines. The clean sponge fines can be pressed into briquettes and sintered at elevated pressures, or mixed with an alkali metal refractory metal halide slat, pressed at elevated pressures into sponge fines/salt briquettes and dried or pressed into briquettes, dried and packaged, or pressed into briquettes and stored wet. The briquettes are non-pyrophoric.

Abstract: A method for producing solid fertilizer from liquid manure or from sludge includes mixing the same with harvest leftovers. The liquid substance (manure, sludge) is intimately mixed with the harvest leftovers during grinding. The solids are ground to a particle size of a few microns. The particles adsorb and absorb the liquid substance fully, so that a solid fertilizer product results which neither smells nor endangers the ground water. All of the valuable materials from the liquid substance and from the harvest leftovers are retained in the finished product, which is a high potency fertilizer. The fertilizer can be applied with methods and devices which are conventionally used in agriculture. An apparatus for performing the method includes a grinder/blender which is supplied independently from a harvest leftover storage and from a liquid substance storage. The materials are measured for exact mixture and the pH value may be adjusted.

Abstract: A process for preparing toner compositions comprising: coinjecting into a continuously operating fluid energy mill, feed toner particles, and a liquid component; and separating the resulting comminuted toner particles.

Abstract: A poultry and swine pulverizing or grinding apparatus comprises an enclosed housing having an inlet end and an outlet end. A grinding drum is rotatably mounted within the enclosed housing and provided with raised cutting teeth extending in a helical orientation along the longitudinal length of the grinding drum. A carcass retention element is positioned adjacent the length of the grinding drum and cooperates therewith to facilitate pulverizing or grinding of animal carcasses by the grinding drum into small size particles which exit the housing through the outlet end. The grinding drum of the apparatus is motivated by an operatively connected motor. Also described is an automated system for preparing animal carcasses for lactic acid fermentation and/or further processing utilizing the aforesaid grinding apparatus.

Abstract: A method for the contamination-free comminution of semiconductor material cludes an apparatus by which the method is carried out. The method includes creating at least one liquid jet by applying pressure to a liquid and forcing it through a nozzle, and directing the liquid jet against the semiconductor material, so that it impinges on its surface at high velocity. The apparatus includes a container for receiving comminuted semiconductor material, at least one nozzle through which a liquid jet is directed at high velocity against the semiconductor material to be comminuted, a conveyor device for removing the comminuted semiconductor material from the container, means for releasing and interrupting the liquid jet, and means for positioning the nozzle and/or advancing the semiconductor material.

Abstract: The invention relates to a method of effecting a physico-chemical reaction, in which method a crystalline or amorphous substance is crushed or ground. In the method according to the invention, as soon as a new fractured surface is formed, it is brought into immediate contact with an environment V1 the physico-chemical property of which is so selected that a firm bond or compound is formed between the fractured surface and the molecules of the environment, at least one molecule of said bond or compound being adapted to its purpose for the further treatment of the crushed or ground material in another environment V2, whereby the physico-chemical property of the environment V1 is further so selected that components disadvantageous in view of the further treatment of the crushed or ground material are prevented from getting to the fractured surface.

Abstract: A clean refractory metal SWARF particle product is made from refractory metal SWARF. The SWARF particles are produced with coolant at a temperature less than 650.degree. C. to prevent formation of refractory metal oxides and nitrides. The SWARF particles are comminuted to reduce the particle size of the SWARF slivers and to liberate residual coolant The comminuted SWARF slivers are washed with a displacement wash to remove the bulk of the coolant and subject to a counter current wash to remove substantially all of the coolant components to produce to clean SWARF particles. The clean SWARF particles can be pressed into briquettes and sintered at elevated pressures or mixed with an alkali metal refractory metal halide salt, pressed at elevated pressures into SWARF/soft briquettes and dried. The briquettes are non-pyrophoric.

Abstract: This invention relates to a method of using an apparatus is provided for the accelerated bioremediation of treated contaminated material. The material is treated with chemical and/or biological amendments for facilitating accelerated bioremediation thereof. The apparatus comprises a system for for generating a treated contaminated material entraining air stream at a predetermined velocity for entraining the treated contaminate material therein for microenfractionating the treated contaminated material. In this way, accelerated bioremediation is facilitated. In another form of the invention, a method of accelerated bioremediation of treated contaminated material is provided.

Abstract: A kaolin clay slurry having a reduced viscosity is manufactured by a process which comprises the sequential steps of mechanically working an undispersed crude kaolin clay material having a solids content of at least about 65 percent, by weight, under conditions which insure that the kaolin clay material will be subjected to an energy level of at least 10 horsepower-hours per ton of dry kaolin clay material and then subjecting the mechanically worked kaolin clay material to centrifugation to substantially remove any particles having a diameter less than about 0.2 microns.

Abstract: Aggregate is separated from sludge consisting of, what is called, "the residual raw concrete" remaining in a raw concrete mixing truck from which raw concrete has been discharged, and waste water resulting from washing the mixing truck. Then, the air is forced into the sludge to form bubbles. A chemical admixture in the sludge is allowed to adhere to the bubbles, and an admixture coating within the sludge is destroyed, thereby promoting the hydration of the cement. Subsequently, the resultant sludge is dehydrated to obtain a dehydrated cake of high hardness. Powder formed of the same quality of the cake is spread over the cake, which is then cured for a few hours. The resultant cake is then crushed so that granular aggregate can be formed.

Abstract: This invention is directed to a shredding machine utilizing a lubrication process to increase the shredding capacity and service life of the machine. More specifically, the invention discloses a distribution manifold containing a plurality of uniformly dispersed pores which discharge fluid across the cutting elements of the shredding machine in a precise and even manner. The pore diameter and length can be chosen to provide for variable fluid discharge rates. Additionally, this invention relates to a lubrication discharge system which utilizes an actuating means that controls the discharge intervals over which the porous manifold releases the fluid. Provisions are included which allow for the lubrication discharge system to operate by use of a pump, or by the mere force of gravity in combination with a control valve.

Abstract: A method for reducing the size of coal particles includes the steps of inoculating a coal sample with an anaerobic bacteria or decarboxylating enzyme therefrom and incubating the inoculated sample. The microbes and/or decarboxylating enzymes biochemically modify the coal to reduce the size of the coal to ultra-fine particles. The biotreatment modifies the coal so as to improve its dispersibility in coal-water slurries.

Abstract: A method and apparatus for the cleaning of plastic flakes to be recycled. Water is added to the plastic flakes and high shear agitator is provided so that dirt, paper and other contamination are removed from the surface of the plastic flakes. The contaminant containing water is then separated from the cleaned plastic flakes. Batch and continuous embodiments of the present invention are disclosed.

Abstract: A method of treating plasterboard production scrap wherein the pieces of the plasterboard scrap having the plaster attached to paper components, is passed through an apparatus which comprises a cylindrical housing in which radial arms carry ploughshares riding along the wall of the vessel and cutting heads are provided between the paths of the ploughshares. The apparatus so reduces the pieces that a homogeneous mixture of fibers of the paper components and granular gypsum is formed. This product mixed with raw gypsum provides a calcinable mixture which can be calcined for use in producing additional plasterboard.