Chlorine dioxide prodn. as part of paper paste mfr. - by reacting sodium chlorate with sodium sulphate and hydrochloric acid and removing the salt (BR270776)

摘要

In a process in which a paper paste is produced by contacting a cellulosic fibre with a paste forming liquor contg. Na2S and NaOH, sepg. the paste from the used liquor and regenerating the liquor to obtain a white liquor which is recycled as part of the liquor added to the fibres together with added Na2SO4 to compensate for the loss of soda and S, and bleaching using chlorine dioxide and purifying the paste, the ClO2 is formed by reacting NaClO3 with HCl in the presence of H2SO4 and a mixt. of NaCl and Na2SO4 is recovered, the Na2SO4 being used to supply the Na and the S as above. The amount of feedstock for making the ClO2 is reduced compared with prior art and since the NaCl is sepd. from the Na2SO4, no build up of salt occurs to produce a dead charge.