초록 ▼

A method for reducing or eliminating the formation of salt scale upon process equipment caused by precipitation of insoluble salts during the bleaching of pulp. The pulp is subjected to a bleaching sequence which includes a plurality of pulp treatment steps, wherein at least one pulp treatment step

A method for reducing or eliminating the formation of salt scale upon process equipment caused by precipitation of insoluble salts during the bleaching of pulp. The pulp is subjected to a bleaching sequence which includes a plurality of pulp treatment steps, wherein at least one pulp treatment step is conducted under alkaline conditions and at least one pulp treatment step is conducted under acidic conditions. A filtrate stream which contains dissolved insoluble salts therein is thus generated, and at least a portion of the filtrate stream is combined with an alkaline stream and pulp to cause the salts to associate with the pulp, thus removing the salts from the filtrate stream to reduce or eliminate the formation of salt scale upon process equipment during the bleaching of the pulp.

대표청구항 ▼

A method for reducing or eliminating the formation of salt scale upon process equipment caused by precipitation of salts during the bleaching of pulp which comprises: (a) subjecting the pulp to a bleaching sequence which includes a plurality of pulp treatment steps, wherein at least one pulp treatme

A method for reducing or eliminating the formation of salt scale upon process equipment caused by precipitation of salts during the bleaching of pulp which comprises: (a) subjecting the pulp to a bleaching sequence which includes a plurality of pulp treatment steps, wherein at least one pulp treatment step is conducted under alkaline conditions and includes an alkaline oxygen delignification stage, and at least one pulp treatment step is conducted under acidic conditions and includes an acidic ozone delignification stage; (b) washing or pressing the pulp after the acidic ozone delignification stage, thus generating a filtrate stream which contains salts therein; (c) combining at least a portion of the filtrate stream with caustic material and pulp which has been subjected to at least one treatment step of the bleaching sequence to cause the salts to associate with the pulp, thus removing the salts from the filtrate stream to reduce or eliminate the formation of salt scale upon process equipment during further processing of the pulp; and (d) subsequently treating the pulp with associated salts in a brightening stage.