气相中碘分子的吸收工艺研究

采用H_2O_2将湿法磷酸中的碘离子氧化成碘分子,之后采用空气萃取法将碘分子以气相吹出,气相中碘分子经还原剂循环洗涤吸收后便于富集回收。气相中碘分子的吸收最佳工艺条件为:以亚硫酸为还原剂,亚硫酸溶液质量分数为8%,反应温度为35℃,吸收塔内含碘气相停留时间为15 s。最佳工艺条件下,气相中碘分子的吸收率为88.37%。50 t/a碘回收装置中,含碘气相冷凝器换热面积为3 000 m~2,吸收塔规格为ф4 300 mm×15 000 mm,材质为钢衬PO,吸收液喷淋量为175 m~3/h。

Study on absorption process of iodine molecule in gas phase

Iodine ions in wet-process phosphoric acid is oxidized into iodine molecules by hydrogen peroxide,then the iodine molecules are blown off by air extraction.The iodine molecules in the gas phase are easy to enrich and recover after recycling and absorbing by the reducing agent.The optimum conditions for the absorption and enrichment of iodine molecules are as follows:the mass fraction of sulfurous acid solution is 8％,which is used as reducing agent;The reaction temperature is 35 ℃;And the residence time of gas containing iodine in absorption tower is 15 s.Under these conditions,the absorption rate of iodine molecules in gas phase is 88.37％.In the 50 t/a iodine recovery device,the heat transfer area of condenser is 3 000 m2,the specifications of absorption tower is φ4 300 mm × 15 000 mm,its material is PO steel,and the spray quantity of absorption liquid is 175 m3/h.