Research On Scale Inhibition And Dispersion Of Modified Lignosulfonate LSA

This paper studied that industrial lignosulfonate LS was modified to graft carboxy by the free radical copolymerization reaction, which was initiated by H2C>2-Fe( II). The structure of modified lignosulfonate LSA was characterized by the infra-red spectrogram. Through measuring, the content of carboxy in LSA obviously improved and the grafting rate of LSA was 11.6%.LSA's scale inhibition property for calcium carbonate, calcium phosphate and zinc scales and dispersing iron oxide were tested by the static scale inhibition test and the bubble test. Through the experiment of three-factor quadratic regression orthogonality, this paper studied quantitatively the relationship between the antiscale rate and the amount of LSA added, the calcium ion content of the solution and the pH value. The regression equation fairly fitted the result of the experiment and can be used for the study of the scale inhibition property and the applicable condition of LSA. Compared LSA's scale inhibition and dispersion properties with some common scale inhibitors', it showed that LSA was a kind of relatively desirable green scale inhibitor.Analysis of the result of scale inhibition test and electron microscope scanning calcium carbonate crystal showed: LSA has strong chelation action for metal ions such as Ca2\ Fe3\ Zn2* and etc. LSA has dispersion action for corpusclesof scale, and it can affect the formation and sticking intensity of scale, resulting in the loosing scale-layer and poor adhesion. LSA leads to crystal's lattic distortion, which can inhibit crystals growing and make the particles of scale loosing to reach the desire of scale-inhibiting.