Dissolution Behavior of Papermaking Grade PCC Filler and Dissolution-inhibiting Effects of Different Inhibitors

摘要

The dissolution behavior of papermaking grade PCC filler was evaluated,and the dissolution-inhibiting effects of alum,alum/sodium silicate,sodium silicate/hydrochloric acid,zinc chloride,and sodium silicate/zinc chloride on PCC filler were evaluated.The results showed that,PCC dissolved strikingly in distilled water with pH 5.85 and alum solution with pH 3.50,and its dissolution in buffer solution was strongly dependent upon the solution pH.Under controlled experimental conditions,alum,alum/sodium silicate,sodium silicate/hydrochloric acid,zinc chloride,and sodium silicate/zinc chloride were all found to be effective to inhibit the dissolution of PCC in distilled water with pH 5.85,and the suspension pH decreased to a certain degree.Alum,zinc chloride and sodium silicate/diluted hydrochloric acid were found to have negligible dissolution-inhibiting effects for buffer solution with pH 5.95,and sodium silicate/zinc chloride was found to be relatively more effective in dissolution-inhibiting performances,and the calcium ion concentration of the suspension filtrate decreased by approximately 30%.The results also indicated that,under certain conditions,sodium silicate/hydrochloric acid was quite effective in dissolution-inhibiting of PCC in alum solution with pH 3.50.