阳离子对弗氏盐法除氯产物特性的研究

The effects of cations（Na⁺，Ca²⁺，Mg²⁺）on crystal structure，settling performance，dewaterability and ion exchange properties of the chloride removal precipitates were studied in order to improve their recovery potential.It was found that in terms of crystal structure，the FS layers formed in MgCl₂ and CaCl₂ solutions were more widely spaced，the FS was more unstable，and the interlayer ions were prone to ion exchange.In addition，the FS products in MgCl₂ showed the largest grain size，which could be attributed to the grain boundaries with doping of Mg²⁺ to change the grain boundary mobility and thereby the local grain growth rate by several orders of magnitude.In addition，differences in FS settling performance produced by the three solutions existed due to differences in Zeta potential.The dosing of PAM could increase the settling velocity by increasing the average particle size of the precipitates，but it did not improve the settling performance much.PAM significantly improved the settling performance of the chloride removal sludge of MgCl₂.The addition of 200 mg/L PAM to the dechlorinated precipitate in MgCl₂ solution reduced SV₁₂₀ from 100.0% to 43.0%.Among the three mechanical dewatering methods，vacuum，plate and frame，and centrifugal，the chloride removal sludge of NaCl was suitable for vacuum dewatering，while the dechlorinated sludge of CaCl₂ and MgCl₂ was suitable for plate and frame dewatering，and the addition of PAM could reduce the bound water content of the sludge cake.