Research Of Separateing SCN～- From Desulfurization Waste Solution By D241 Resin

In this paper, it was researched and discussed the method and techniques of using anion exchange resin to exchange the SCN^- in desulfurization waste solution and the relationship was explored between the proportion of K₂S₂O₃/KOH and KSCN crystal free liquids,the saturation solution volume when crystal appear,the content of KSCN in crystal. The results showed that the dynamic exchange capability of D241 anion exchange resin against SCN^- from KSCN solution and S2O32- form K₂S₂O₃ solution is 296.4mg/g resin and 61.6mg/g resin separately, the multiple is 4.81. Aptly condition of using D241 exchange resin to exchange the SCN^- form desulfurization waste solution also was got, when the flow velocity is 60-100mL/h, the dynamic exchange capability of D241 resin against SCN^- in 1/10 times waste water is 92.79-86.70mg/g resin. The concentration of waste water also has effect on the exchange capability of the resin. When the dilute multiple is 1/2.5, the exchange capability is 93.61mg/g resin. When the dilute multiple is 1/12.5, the exchange capability is 57.04mg/g resin. Bring the two into comparison, the former is 164.1% to the latter.Comparing with NH3 and CH3COONa, the result of using 0.1mol/L KOH to elute the SCN^- which has been exchanged into D241 resin is better. The concentration of KOH has great effort on elute the SCN. The aptly concentration of KOH is 0.5mol/L. And the aptly eluting velocity of flow is 60mL/h. In this condition, use the resolution which volume is 7 times of the resin weight can elute all the SCN. The efficiency have boost 18.39% against the elute velocity of flow is 100mL/L .Remains S2O32- in eluent was removed by CH3COCH3 and CH3OCH3, then the acicular crystals were got. The crystals were dried at 80℃and then analyzed with IR. The results show that the crystals have characteristic absorption peak at 2068cm-1 it is very close to the characteristic absorption peak of KSCN which can be conclude that this crystals is sulfocyanate. The SCN^- containing in the crystals is 53.34%, convert to KSCN is 89.2%.The results of study the crystal relationship of KS2O3 and KSCN solution mixed ratio shows that when the ratio of K₂S₂O₃/KOH is between 0.15 and 0.25, the content of SCN^- and KS2O3 in the crystals is show direct ratio; when the ratio of K₂S₂O₃/KOH is...