Abstract: Apparatus for dampening fibrous material using the alternating pressure process with an airtight and vapor-tight housing (1), with a vacuum line (6), wherein a first directional valve (7) is provided in the vacuum line (6), the housing (1) has at least one closable opening (2, 21, 23) for loading and unloading the housing (1) and a ventilating line (11), and wherein a third directional valve (12) is provided in the ventilating line (11).

Abstract: Apparatus for dampening fibrous material using the alternating pressure process with an airtight and vapour-tight housing (1), with a vacuum line (6), wherein a first directional valve (7) is provided in the vacuum line (6), the housing (1) has at least one closable opening (2, 21, 23) for loading and unloading the housing (1) and a ventilating line (11), and wherein a third directional valve (12) is provided in the ventilating line (11).

Abstract: In order to recover the various components of multiple layer materials, a method uses a refiner or disperser including mutually opposing rotating discs having material engaging surfaces or elements such as teeth. The method includes: adjusting a gap between the discs so that a material is subjected to a shear force that mutually separates its material layers in the form of pieces or fragments in the absence of any substantial disintegration of the layers; pumping the separated pieces of the various layers together with a supplied suspension liquid to a separator; and, separating readily pulped or slushed pieces of the material suspended in the suspension liquid from pieces of the suspended material that are not readily pulped or slushed. The pumping of the separated pieces and suspension liquid to the separator can be via a collection vessel.

Abstract: Method of recovering calcium carbonate from waste material or contained natural calcic material. Calcium is recovered by prepariag an aqueous suspension the material containing calcium to be recovered and by lowering the pH of the suspension to pH<6, preferably pH<4, for providing a spension including an acidic liquid phase containing the calcium compounds in soluble form. Thereafter the pH of the liquid is raised to pH>6, preferably pH>7, by mixing a base therein, for precipitating the main portion of aluminium therein. Thereafter the neutral or basic liquid phase is carbonized by introducing Na2CO3 or NaHCO3 therein, for precipitation of the calcium compounds as CaCO3.