亚硫酸钠回收碘的空气氧化

Air Oxidation of Sodium Sulphite during the Process of Recovery of Iodine

在用亚硫酸钠和碳酸钠混合液吸收含碘废气的过程中遇到了亚硫酸钠被空气氧化的问题.本文研究了在静止吸氧和鼓泡充氧二种条件下亚硫酸钠被空气氧化的各种影响因素.实验表明,在吸氧条件下,pH值对Na_2SO_3的空气氧化速率有很大的影响,该氧化过程是一个比较复杂的过程.在鼓泡充氧的条件下,Na_2SO_3被氧化速率显著加快.在不同的pH值、温度以及催化剂存在情况下,Na_2SO_3的浓度均随时间呈直线下降.本文也给出了用亚硫酸钠和碳酸钠混合溶液吸收含碘废气的实际工艺过程,回收碘的质量符合中国药典的标准.为减少空气氧化造成Na_2SO_3的损失,亚硫酸钠溶液宜新鲜配制。

Mixed solutions of sodium sulphite and sodium carbonate arc used in the absorption of iodine from the waste-gas. Sodium sulphite solutions are ready to be oxidizid by air. Experimental results show that the oxidation rate is remarkable but not very high and greatly influenced by pH values. When Na2SO3 is oxidized by dissolved oxygen. However, when sufficient oxygen is supplied through bubbling air into the solution the concentration of sulphite in the solution decreases rapidly with a character of linear concentration-time relation. The actual process of iodine recovery is described in this paper. It is suggested that fresh solution of sodium su'phite be used for the purpose of decreasing the oxidation.