Abstract: A powder collection unit includes a powder storage having an inlet through which powder including fibers enters and an outlet through which the powder exits, a delivery screw having an elongated shape, disposed in the powder storage, and configured to rotate about a rotation axis to send out and discharge the powder through the outlet, and a powder collection portion coupled to the outlet and having an inner space that collects the powder discharged through the outlet. An end portion of the delivery screw that is adjacent to the outlet protrudes outwardly from the powder storage through the outlet and resides in the inner space of the powder collection portion.

Abstract: A method for processing feedstock is described, characterized in that incoming feedstock is processed to selectively recover biogenic carbon material from the incoming feedstock. In some embodiments the incoming feedstock is comprised of mixed solid waste, such as municipal solid waste (MSW). In other embodiments the incoming feedstock is comprised of woody biomass. In some instances, the incoming feedstock is processed to selectively recover biogenic carbon material from the incoming feedstock to produce a processed feedstock having biogenic carbon content of 50% and greater suitable for conversion into biogenic carbon Fischer Tropsch liquids. The high biogenic carbon Fischer Tropsch liquids may be upgraded to biogenic carbon liquid fuels. Alternatively, the incoming feedstock is processed to selectively recover plastic material from the incoming feedstock to produce a processed feedstock having biogenic carbon content of 50% or less.

Abstract: A method of forming a molded article includes preparing a fiber suspension by liquidizing fibrous material in a suspending liquid using at least one high shear mixer. The fiber suspension is fed to the molding surface of a porous mold. The suspending liquid is removed via the pores of the porous mold to deposit suspended fibers on the mold surface as a molded article. Removing the suspending liquid is achieved by pressing a bladder formed of a flexible impermeable membrane against the article using pressure applied behind the membrane. The molded article is removed from the porous mold dried using microwave radiation generated using at least one magnetron. A molding apparatus is use in the method and a molded article is produced by the method.

Abstract: An industrial system for refining plant fibers by steam explosion includes: a pre-chamber; a loader for loading the pre-chamber with sheaves of a fibrous plant, a spark gap arranged under the pre-chamber, a valve upstream of the pre-chamber, a valve separating the pre-chamber from the spark gap when in the closed state and opening a passage with a diameter of at least the smallest of the diameters of the pre-chamber and the spark gap when in the open state; a washing system arranged inside the spark gap for washing the spark gap and dragging the fibers downwards; a mobile basket for receiving fibers with a position under the spark gap for receiving fibers; a liquid-recovery device, arranged under the basket and under the spark gap, a receiving chamber receiving the basket loaded with fibers; and a drying chamber.

Abstract: A raw material supply device includes a housing that stores an aggregate of small pieces, a discharge port through which the small pieces are discharged from an inside of the housing, a rotor provided in the housing and including a protruding portion, and a magnet provided on the discharge port or on a downstream side of the discharge port. In addition, it is preferable that the raw material supply device further include a passage route that communicates with the discharge port and through which the small pieces pass, in which at least one pair of the magnets is disposed on one side and the other side via the passage route.

Abstract: A housing portion includes first and second inclined surfaces facing each other and inclined such that a distance between the first and second inclined surfaces decreases downward in a vertical direction. A third inclined surface located between the first and second inclined surfaces, facing the first inclined surface, inclined such that a distance between the third and first inclined surfaces decreases downward in the vertical direction, and having a first gap with respect to the first inclined surface is provided. A fourth inclined surface located between the first and second inclined surfaces, facing the second inclined surface, inclined such that a distance between the fourth and second inclined surfaces decreases downward in the vertical direction, and having a second gap with respect to the second inclined surface is provided. A suction blower causes a mixture to pass through the first and second gaps, and collects the mixture.

Abstract: Pulp fiber containing little ash is effectively recovered from a used sanitary product containing the pulp fiber and a polymer absorbent. The method according to the present invention comprises: a step for treating the used sanitary product with an ozone-containing gas and thus decomposing and removing at least a portion of the polymer absorbent in the used sanitary product; and a step for stirring the used sanitary product, that has been treated with the ozone-containing gas, in water or an aqueous solution containing an antiseptic and thus decomposing the used sanitary product into constituents. If required, the method may further comprise a step for separating the pulp fiber from the decomposition product obtained by the decomposition step.

Abstract: Pulp fiber containing little ash is effectively recovered from a used sanitary product containing the pulp fiber and a polymer absorbent. The method according to the present invention comprises: a step for treating the used sanitary product with an ozone-containing gas and thus decomposing and removing at least a portion of the polymer absorbent in the used sanitary product; and a step for stirring the used sanitary product, that has been treated with the ozone-containing gas, in water or an aqueous solution containing an antiseptic and thus decomposing the used sanitary product into constituents. If required, the method may further comprise a step for separating the pulp fiber from the decomposition product obtained by the decomposition step.

Abstract: A raw material supply device includes a plurality of supply portions for supplying the raw material, a detection portion for detecting a state of the supply portion, and a control portion for controlling the supply portion, in which when the plurality of supply portions are in a normal state, the control portion switches the supply portions at a predetermined timing, and causes each of the supply portions to supply the raw material.

Abstract: Apparatus features a signal processor or signal processing module configured to: receive signaling containing information about a central air-core of an overflow pipe of a hydrocyclone where fluid flow is concentrated in an outer annular region of the overflow pipe that is against an inner wall of the overflow pipe during a normal operation of the hydrocyclone; and determine corresponding signaling containing information about a collapse of the central air-core of the overflow pipe of the hydrocyclone during an abnormal operation of the hydrocyclone, based upon the signaling received. The signaling contains information about a fluid flow rate of the fluid flow by detecting a change in the magnitude of a force and/or a moment on the probe.

Abstract: A device and method for cleaning contaminated solid-liquid mixtures by removing impurities and contaminants from an aqueous paper fiber suspension by flotation. Apparatus includes a first conduit (2) for a liquid, a second conduit (3) for a solid-liquid mixture, a third conduit (4) connecting first and second conduit (2, 3), a Venturi mixing element (5) with cones (7, 11), having small through-opening into chamber (9) which forms a cavity with small through-opening (12, 13) of the cones; the through-opening of first cone (7) connected with first conduit (2) and the rough-opening connected to second conduit (2), the small through-opening (12) of first cone (7) and the non-conical conduit sections arranged in longitudinal axial alignment, a fourth conduit (6) for conveying gas, wherein the fourth conduit (6) opens to the Venturi mixing element (5), and a fractionator arranged downstream of the second conduit (3) for removing the foam produced by flotation.

Abstract: A separation device includes a first shredding unit, and a first separation unit. The first shredding unit shreds a disposable diaper (processing target) containing a plastic (first material) and a water-absorbent polymer (second material) adhering to the plastic. The first separation unit has a first tubular portion, and a first beating member. The first separation unit separates the water-absorbent polymer passing through first holes from the disposable diaper by beating the disposable diaper with a plate surface of the first beating member with the first tubular portion being rotated in a state in which the disposable diaper shredded by the first shredding unit is accommodated therein.

Abstract: The present invention provides a method for preserving recycled fiber by using biocides and a method for manufacturing paper using recycled fiber. The method for manufacturing paper, using recycled fiber as a raw material, comprises pulping procedure: pulping the raw material containing recycled fiber, and papermaking procedure: producing the paper with the pulp slurry obtained in the pulping procedure; wherein the total starch content of recycled fiber is measured before recycled fiber is pulped, and when the total starch content of recycled fiber is higher than a predetermined value, one or more biocides are added during the pulping procedure.

Abstract: The present invention relates to a composition comprising hedgehog shaped particles, at least one binder, and at least one hydrophobizing agent and/or at least one hydrophilizing agent, a method for controlling the wettability of substrate surfaces using these compositions, as well as a material comprising these compositions.

Abstract: A method for processing ash from waste incineration plants by wet classification includes mixing the ash with a liquid in a mixing hopper. After screening, the mixture is fed to a first classifying stage, including an upflow classifier and an upstream hydrocyclone, where it is separated into a good fraction and a residual fraction. The residual fraction is drawn off as a suspension on an upper side of a fluidized bed of the upflow classifier. The good fraction is drawn off on an underside of the fluidized bed. A pass through fraction is fed back into the hydrocyclone installation and a material flow containing particles which are smaller than a separation particle size is separated as cyclone overflow. The cyclone overflow is separated in a second classifying stage into a fine particle mineral fraction and a residue which has a grain size upper limit between 20 ?m and 50 ?m.

Abstract: A sheet manufacturing apparatus can determine if the sheets supplied as feedstock have already been recycled. The sheet manufacturing apparatus has a supply unit configured to supply feedstock; a defibrating unit configured to defibrate the feedstock; an depositing unit configured to deposit defibrated material defibrated by the defibrating unit; a forming unit configured to form a sheet from a web laid by the depositing unit; a marking unit configured to apply a mark to at least one of the web and the sheet; and a reading unit configured to read the mark imparted to the feedstock when a sheet having mark imparted thereto is supplied as the feedstock.

Abstract: The present invention provides methods for deinking wastepaper by combined use of cutinase and chemical reagents, which relates to the field of enzyme engineering. The method comprises the following steps: pulp preparation, enzymatic hydrolysis, pulp washing and dewatering, and flotation. The enzyme for enzymatic hydrolysis is cutinase at a concentration of 10-20 U/g absolute dry pulp; and 0.5-4% Na2SiO3, 0.1-0.8% MgSO4, 0.1-0.8% EDTA, 0.1-4% H2O2 are used in the chemical treatment. With combined use of enzymatic and chemical treatment, the present invention has solved the problem of the current enzymatic method for deinking that requires large dosage of enzymes and thus high cost. Through proper choice of the kind and the amount of chemical reagents, synergistic effects of the enzymatic and chemical treatment can be achieved, thus increasing the effectiveness of the deinking process.

Abstract: The present invention discloses a method of utilizing refuses in urban and rural areas. The method includes a refuses collection step, a refuse distributing step, a primary magnetic separation step, a primary crushing step, a primary elutriation and floatation step, a uniform cutting step, an acidification and anaerobic treatment step, a selection and separation step, a buffering and adjusting step, an additional anaerobic treatment step and a sludge sedimentation and concentration step. The present invention can make the anaerobic treatment method continuatively dispose the refuses, thereby thoroughly solving the problem that non-anaerobic refuses such as waste plastics, water fiber etc. can not be recycled and completely recycling resources in the refuses.

Abstract: The present invention refers to a process for bacterial stabilizing aqueous preparations like e.g. calcium carbonate slurries and a composition which can be used for the biocidal treatment of such aqueous preparations.

Abstract: A sheet manufacturing apparatus includes a defibrating unit configured to defibrate stock material in a dry process, a transferring tube configured to transfer the stock material to the defibrating unit, and a magnet unit arranged such that a magnetic surface is exposed an inside of the transferring tube without being protruded inner than an inner surface of the transferring tube.

Abstract: A sheet manufacturing apparatus includes a defibrating unit configured to defibrate a defibration object, a measuring unit configured to acquire information relating to the moisture contained in the defibration object, and a controller configured to modify an operating condition of the defibrating unit based on the information.

Abstract: A sheet manufacturing apparatus includes a measuring unit configured to measure thickness and air permeability of a defibration object containing fibers, a defibrating unit configured to dry-defibrate the defibration object, and a classifying unit configured to separate and remove, by airflow classification, foreign substances other than the fibers from the defibrated material defibrated at the defibrating unit.

Abstract: The present invention relates to a fibrous material composition having a predefined fraction of fresh fibres and/or waste paper with a further fraction of sweet grass, sedge, seagrass and/or algae fibres and adjuvants and water, where the weight fraction of sweet grass, sedge, seagrass and/or algae fibres is greater than 1 and less than 100 wt. % of the total material mass, in each case calculated as oven-dry material fraction. The invention further relates to a method for producing the fibrous material mixture and its use for producing fibrous-material-containing products.

Abstract: Methods to control organic contaminants in fibers are described. One method involves contacting the fibers with a) at least one zeolite and optionally b) detackifier, or an ester hydrolyzing enzyme, or both, for a sufficient time and in a sufficient amount to control the organic contaminants present in the fibers. This method is effective to reduce stickies in paper mill furnish formed with recycled fibers. A method for pitch control in paper mill furnish formed with virgin fibers is also provided. Resulting paper products formed from the processed fibers are also described as well as methods to make them.

Abstract: A method of splitting hollow cellulosic fibers employs the steps of wetting the fibers, feeding the wet fibers to a gaseous flow, and conducting the gaseous flow carrying the fibers through a venturi tube, the pressure drop in the venturi tube throat bringing a pressure difference between liquid inside the fibers and gas outside of the fibers and causing the fibers to split in their longitudinal direction, to open the lumen inside the fibers.

Abstract: The purpose of the present invention is to provide technology for regenerating pulp having high quality with compact pulp regenerating equipment and less energy. In the pulp regenerating method of the present invention, pulp slurry containing 1.5 wt % or more of a solid component including waste paper pulp is separated into a long fiber fraction and a short fiber fraction by using an outward type slit screen including an opening portion having a slit width in the range of 0.1 mm to 0.3 mm. The solid component ratio of the long fiber fraction and the short fiber fraction is in the range from 10:90 to 60:40, and the difference in Canadian Standard Freeness of the long fiber fraction and the short fiber fraction is in the range of 100 ml to 300 ml.

Abstract: A method of forming a dilute water slurry for water felting a basemat for an acoustical ceiling tile comprising delivering a bale of compressed mineral wool with a density of at least 8 lbs. per cubic foot at an unbaling station, releasing a binding holding the bale in compression, mechanically separating the fibers of a mineral wool bale with mechanical instrumentalities arranged to disperse the fibers to a generally uniform density of less than 2 lbs. per cubic foot prior to passage of the fibers through the tank inlet, and causing the separated mineral fibers to pass into the mixing tank for contact with water suspended binder.

Abstract: To provide a paper recycling device capable of recycling paper of increased whiteness level that can be widely used for applications other than paper for newspapers, the paper recycling device of the present invention has a dry type defibrator for crushing and defibrating paper, a first transport pipe for transporting defibrated material that was defibrated by the dry type defibrator, a cyclone for air classifying and deinking the defibrated material transported by the first transport pipe, a second transport pipe for transporting the defibrated material that was deinked by the cyclone, and a paper forming machine for forming paper with the defibrated material transported by the second transport pipe.

Abstract: Deinking of waste paper is obtained with the use of a hydrophobic kaolin-based deinking composition. The hydrophobic kaolin-based deinking composition is produced by hydrophobizing the kaolin clay and then blending the hydrophobic kaolin-based particles with a deinking surfactant. Separation and removal of ink is achieved either by washing deinking, flotation deinking or combination of these methods.

Abstract: A system and method of producing both loose cellulose insulation and bonded fiber/cellulose insulation products utilizing shredded paper particles, including making shredded paper particles in a shredded paper particle line and diverting a portion of the shredded paper particles to a bonded fiber/cellulose product line whereby the shredded paper particle line forms an in-process production and delivery of shredded paper particles to the bonded fiber/cellulose product line. Moisture is added to the shredded paper particles at the bonded fiber/cellulose product line, and bonded fiber/cellulose insulation products are produced with the bonded fiber/cellulose product line from the diverted portion of shredded paper particles and loose cellulose insulation is produced from shredded paper particles that are not diverted from the shredded paper particle line.

Abstract: An assembly of opposing discs or cones for a disperser where each disc or cone has mounted to it a plate or an array of plate segments with a front surface on each plate or array of plate segments and each surface has a series of bars, grooves and dams. The bars are in rows, with the rows separated by annular dams at substantially fixed radial locations, and the grooves are adjacent the bars in the rows so that the grooves form a serpentine passage extending radially between the opposing plates or array of plate segments on the opposing discs or cones. The opposing plate or array of plate segments are arranged such that the annular dams on one plate or array of plate segments face roughly the middle of the row of bars on the opposing plate or array of plate segments.

Abstract: Methods and apparatus are provided for exploiting coated paper products such as coated paper cups. End products include biofuels that have a high energy density. The biofuels may be mixed with coal or other fuels and have good binding characteristics. In some embodiments, useful chemicals such as HMF are produced. The methods involve heat treatment at relatively mild temperatures and pressures under acidic conditions.

Abstract: [Object] It is to provide a process of manufacturing recycled paper pulp with high efficiency from newspaper (waste paper) or waste printed paper as a raw material, which is disposed and recovered from homes and offices, through a deinking process using a specific surfactant and electrolyzed water.

Abstract: A barrier packaging material containing a composite which comprises i) a cellulosic layer; ii) at least one metal layer which will dissolve under alkaline conditions; and iii) at least one polymer layer, in which the polymer is hydrolysable under alkaline conditions. The invention also relates to articles comprising the barrier packaging material. Further, the invention concerns the use of a polymer, which is hydrolysable under alkaline conditions, as a protective layer in barrier packaging products. In addition the present application is also concerned with a method for recycling the aforementioned barrier packaging products. Specifically the barrier packaging products are initially taken in an aqueous wastepaper suspension which is either pulped in an alkaline medium and/or treated in an alkaline medium in a deinking process and in which the metal and polymer are then separated from the cellulosic fibres contained in the cellulosic layer.

Abstract: To provide a paper recycling device capable of recycling paper of increased whiteness level that can be widely used for applications other than paper for newspapers, the paper recycling device of the present invention has a dry type defibrator for crushing and defibrating paper, a first transport pipe for transporting defibrated material that was defibrated by the dry type defibrator, a cyclone for air classifying and deinking the defibrated material transported by the first transport pipe, a second transport pipe for transporting the defibrated material that was deinked by the cyclone, and a paper forming machine for forming paper with the defibrated material transported by the second transport pipe.

Abstract: The purpose of the present invention is to provide technology for regenerating pulp having high quality with compact pulp regenerating equipment and less energy. In the pulp regenerating method of the present invention, pulp slurry containing 1.5 wt % or more of a solid component including waste paper pulp is separated into a long fiber fraction and a short fiber fraction by using an outward type slit screen including an opening portion having a slit width in the range of 0.1 mm to 0.3 mm. The solid component ratio of the long fiber fraction and the short fiber fraction is in the range from 10:90 to 60:40, and the difference in Canadian Standard Freeness of the long fiber fraction and the short fiber fraction is in the range of 100 ml to 300 ml.

Abstract: A method of splitting hollow cellulosic fibers employs the steps of wetting the fibers, feeding the wet fibers to a gaseous flow, and conducting the gaseous flow carrying the fibers through a venturi tube, the pressure drop in the venturi tube throat bringing a pressure difference between liquid inside the fibers and gas outside of the fibers and causing the fibers to split in their longitudinal direction, to open the lumen inside the fibers.

Abstract: The present invention provides a process for deinking printed waste paper comprising the steps of: a) converting the printed waste paper to an aqueous pulp slurry in a pulper, where ink is detached from paper pulp; b) subjecting the pulp slurry to flotation in order to remove hydrophobic contaminants including ink from the pulp slurry, said flotation being carried out in the presence of a deinking chemical additive comprising modified silica obtained by treating hydrophilic silica particles with a hydrophobic organic liquid or modified metal silicate obtained by treating hydrophilic metal silicate particles with a hydrophobic organic liquid or a mixture of such modified silica and modified metal silicate. The present invention increases the yield of the flotation step without affecting the brightness of the flotation accept.

Abstract: The present invention relates to a novel pulp composition for paper or solid board production comprising an oxidized recovered paper pulp and/or an oxidized mechanical pulp into which from 1 to 500 mmol of carboxyl groups per kg and from 1 to 200 mmol of aldehyde groups per kg have been introduced by oxidation. The invention also relates to paper and solid board based on such a pulp composition and also to a process for producing such paper or solid board. The invention also relates to the use of oxidized recovered paper pulp and/or oxidized mechanical pulp for improving the retention and drainage properties of a pulp suitable for producing paper or solid board. The invention further relates to the use of oxidized recovered paper pulp and/or oxidized mechanical pulp for improving, i.e., increasing, the dry strength of paper and solid board.

Abstract: A system for forming bonded fiber/cellulose products includes a shredded paper particle manufacturing line producing shredded paper particle-based products, such as insulation, a bonded fiber/cellulose product line, and a collector for collecting a portion of the shredded paper particles generated by the shredded paper particle line for the bonded fiber/cellulose product line.

Abstract: The invention relates to a method for preparing paper pulp from recycled paper containing contaminants characterized in that it comprises a first step of agitating the paper in the presence of water in order to obtain a mixture of fibers and contaminants in suspension, a second step of coarsely screening said mixture in order to separate the coarse contaminants from the rest of the suspension, a third step of fine screening in order to separate the fine contaminants from the coarsely-screened suspension and a fourth step of washing said coarse and fine contaminants in order to separate the reusable fibrous materials from the rest of the non-reusable contaminants. In particular, the invention aims to provide a method for preparing paper pulp that is capable of producing a good quality paper pulp from highly-contaminated recycled paper, especially having a contaminant level in the dry state that is greater than or equal to 15% by weight.

Abstract: A composition and method for deinking is disclosed. The composition and method contain an activated magnesium hydroxide or a magnesium hydroxide.

Abstract: A used paper recycling apparatus capable to be installed in small office or general household, friendly to environment and low in running cost, and assuring high confidentiality. A used paper recycling apparatus comprising a pulp making section for crushing and beating used paper and making into pulp, a paper making section for recycling paper by making used paper pulp from the pulp making section, and a control section for driving and controlling by interlocking the pulp making section and paper making section, which are incorporated in a furniture size apparatus case, in which the pulp making section includes a crushing unit for stirring and grinding the used paper, and a beating unit for beating the crushed used paper from the crushing unit, and the crushing unit and beating unit are circulating the used paper pulp.

Abstract: The present invention provides methods for deinking printed waster paper—particularly methods that use a deinking composition that includes a hydrophobically-modified inorganic particle (“MIP”) to improve ink collection efficiency under traditional alkaline, reduced alkali, and true neutral deinking conditions. Deinking compositions are provided that include a hydrophobically-MIP substrate, a nonionic surfactant, and a fatty acid, or mixtures thereof. The improved ink collection of the present invention can result in deinked pulp of high quality and/or yields that has excellent brightness and effective residual ink concentrations (“ERIC”) values.

Abstract: A fiber mass suspension is produced by mixing together a fiber material (FM) and water (W) in a pulper (1). The formed fiber mass suspension is divided into an accept fraction and a reject fraction. The reject fraction is supplied continuously to a first secondary pulper (2) for further screening and defibring. The accept fraction formed in the first secondary pulper (2) is supplied continuously for further processing and the reject fraction formed in the first secondary pulper (2) is supplied continuously to a second secondary pulper (3) for further processing. The accept fraction formed in the second secondary pulper (3) is supplied continuously for further processing.

Abstract: A process for reclaiming food-contaminated solid waste streams from fast food restaurants, casual dining restaurants, cafeterias, schools, colleges and universities, concession stands, arenas, stadiums, movie theaters, large city street trash bins and other entertainment venues, and other places that offer simple food items for dine in or carry-out that are currently sent to a land fill. The inventive process offers total solid waste reclamation with zero waste water discharge, zero landfill and minor source air emissions, resulting in 100% reclamation and a 100% sustainable process. This process can also be used on solid waste from reclamation centers and manufacturers who currently land fill their waste.

Abstract: An ink coating composition is disclosed herein. The ink coating composition includes a polymer latex and an adhesion promoting agent. A non-ionic surfactant is also included in the ink coating composition. The non-ionic surfactant has an HLB value ranging from about 6 to about 15. The ink coating composition also includes a balance of water.

Abstract: An injector for a flotation cell, comprising a feed channel for feeding a fiber suspension flow to the flotation cell, a flow distribution element for distributing the fiber suspension flow fed to the injector into partial flows, a mixing apparatus for mixing air with the fiber suspension flow, and at least one air input point for sucking air to be mixed with the fiber suspension flow into the injector. The feed channel, the flow distribution element and the mixing apparatus are in the injector arranged with respect to one another such that a flow direction of the fiber suspension flow in the feed channel is substantially opposite to a flow direction of the fiber suspension flow through the flow distribution element and the mixing apparatus.

Abstract: An injector of a flotation cell, the injector comprising a feed pipe for feeding a fiber suspension flow into the flotation cell, a mixing apparatus for mixing air into the fiber suspension flow and at least one air feed connection arranged before the mixing apparatus for feeding air into the injector. The injector further comprises a nozzle section which is arranged before the mixing apparatus and comprises an aperture plate provided with apertures and nozzles fixed to the aperture plate substantially at the apertures after the aperture plate, there being open spaces between the nozzles. The air to be fed from the air feed connection is arranged to flow into the spaces between the nozzles and further into the mixing apparatus with the partial flows of the fiber suspension flow entering from the nozzles.

Abstract: There are provided a method of recovering a base paper for gypsum board for continuously and efficiently recovering a base paper for gypsum board from a waste material of gypsum board including a gypsum core and the base paper for gypsum board adhering thereto. The method of recovering a base paper for gypsum board includes steps of breaking the waste material of gypsum board, separating a gypsum component and a paper piece of the base paper for gypsum board from the broken waste material of gypsum board, and washing the separated paper piece with water using a rotary drum-type washing device so as to eliminate a gypsum component adhering to the paper piece.