Method of polysulphide treatment of lignocellulose material in alkalic pulp production

Abstract From the Canadian patent

The invention relates to the production of polysulphide for the treatment of wood chips so that the consumption thereof is reduced in sulphate digestion of paper pulp. The pulp is preferably subjected to such a bleaching that implies access to oxygen in the pulp factory. In an impregnation stage the wood chips are caused to react with black liquor, or digestion liquor prepared from white liquor and containing black liquor while introducing, oxygen of appropriate concentration. The content of monosulphide and to a certain extent other sulphur compounds also of the liquors then forms polysulphide in contact with the wood chips which instantaneously adsorb polysulphide. The generation of …