Verfahren zum Ablösen von Druckfarbe aus Altpapier

摘要

To separate ink and/or other foreign matter from used paper, a suspension of the used paper is prepared using water containi tenside. The pH value is set to at least 8 by an alkali reagent containing or composed of lime. The alkali reagent is slaked lime and/or calcinated lime in a solid form or as a watery suspension containing it or compose it. A watery lime suspension is used as the alkali reagent. To set the pH value at least at 8, the lime product and preferably calcium hydroxide, is used at a rate of 0.05-1.5 wt% and preferably 0.2-1.0 wt% and especially 0.3-0.6 wt%. Additional additives be used of silicate of soda, bleaching agents, or optical brighteners in the suspension.