Akzo Nobel N.v.

Eka Chemical Ab

Roy Hammer-Olsen

John Charles Sokol

Magnus Linsten

Roland Pudas

G&ouml;ran Sundstr&ouml;m

Ingrid Velander

Johan Sundqvist

Bjorn Svedin

The invention relates to a process for production of an alkaline hydrogen peroxide solution and an acidified alkali metal salt solution containing chlorate in an electrochemical cell including an anode compartment provided with an anode and a cathode compartment provided with an oxygen reducing cathode. In the cathode compartment an aqueous alkali metal hydroxide and hydrogen peroxide is formed, wherein the molar ratio MOH:H,O,for the net production thereof is maintained from about 0.1:1 to about 2:1. Also a process for simultaneous production of chlorine dioxide is disclosed.

Chemical method

A substantial and increasing problem with the pulping chemical recovery system, is the presence of chloride and potassium in the spent liquor entering the recovery boiler. Chloride and potassium increase the stickiness of carryover deposits and dust particles to the recovery boiler tubes, which accelerate fouling and plugging in the upper part of the recovery boiler. The present invention relates to a process by which the content of potassium ions in a recovery system for pulping chemicals can be reduced. The process comprises bringing spent liquor to a recovery boiler, burning said spent liquor, collecting precipitator dust formed, forming a solution by dissolving the precipitator dust in a liquid, where the solution of precipitator dust is subjected to a treatment with an inorganic ion exchange material in order to remove at least a part of the potassium therein.

Recovery process in a pulp mill

Growing community of inventors

Ljungaverk, Sweden

Roy Hammer-Olsen