Abstract: In making paper from an aqueous papermaking stock a binder comprising colloidal silicic acid and cationic starch is added to the stock for improving the paper or the retention of the stock components, or is added to the white water for reducing the pollution problems or recovering values from the white water.The cationic starch of the binder has a degree of substitution of not less than 0.01, and the weight ratio of cationic starch to SiO.sub.2 is between 1:1 and 25:1.

Abstract: A papermaking process in which an aqueous papermaking stock containing a cellulosic pulp is formed and dried. The stock includes a binder comprising colloidal silicic acid, and cationic starch which is added to the stock before the sheet is formed. The manner of addition involves first adding and intermixing in the stock a portion of the colloidal silicic acid and then the cationic starch and, after an agglomerate has formed, adding and intermixing the remainder of the colloidal silicic acid prior to the formation of the sheet. The method results in improved sheet properties and improved retention of filler and fines on the wire.

Abstract: A glue, substantially based on chlorolignin, for gluing cellulose materials such as wood, particle board etc. Chlorolignin, which is a waste product from the cellulose industry, is an environmentally dangerous substance. It is recovered by membrane filtering of waste liquor, separating out compounds with a molecular weight lower than 1000-2000. It is then used alone, or mixed with common synthetic glues such as melamine-formaldehyde resins, fillers, hardeners etc. Formaldehyde, paraldehyde or ammonium chloride are suitable hardeners and the chlorolignin can also be prepolymerized with formaldehyde and/or paraldehyde.

Abstract: A method for cleaning effluents from bleaching plants which use ultrafiltration for cleaning, preferably after the first extraction stage, by dividing the ultrafiltration into two stages, and between them inserting an alkali treatment stage. The high molecular chlorine compounds are thereby split into innocuous sodium chloride in the permeate from the second ultrafiltration stage, which can be returned to the extraction stage so that with the alkali excess after the splitting, it can cover all or part of its alkali requirement.