Solidification effect of modified hydrotalcite and calcium carboaluminate on chloride ions in FGD gypsum
To improve the solidification effect of chloride ions in FGD gypsum,the solidification of modified hydrotalcite and calcium carboaluminate on chloride ions in desulfurization gypsum is studied.The results show that both solidifying agents have a significant solidification effect on the chloride ions in FGD gypsum,and the content of chloride ions firstly decreased and then increased with the amount of solidifying agents used.When the dosage of modified hydrotalcite and calcium carboaluminate is 5%and 20%respectively,the content of chloride ions in FGD gypsum is the lowest,which is below 400 ppm and meets the requirements for chloride ion content in gypsum products.There is a large interlayer structure space in modified hydrotalcite,whose adsorption capacity for chloride ions exceeded for sulfate ions,so modified hydrotalcite can achieve the adsorption of chloride ions in sulfate solution.At the same time,because the adsorption belongs to a dynamic equilibrium process,there is an optimal dosage for modified hydrotalcite.Calcium carboaluminate belongs to the X-AFm system,and both chloride ions and carbonate ions can serve as X.According to the priority order of X entering the AFm interlayer,chloride ions can replace carbonate ions to enter the AFm interlayer and achieve solidification effect on chloride ions.
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维普
