联碱厂碳化塔洗水制备磷酸铵镁

采用化学沉淀法，以模拟联碱厂碳化塔洗水为原料，制备磷酸铵镁，并采用SEM和XRD技术对产品的晶形和成分进行分析。通过正交实验和单因素优化实验确定较适宜的反应条件为：反应液pH 9.5，n（Mg）∶n（P）∶n（N）=1.2∶1.1∶1.0，反应温度25 ℃。在此条件下，处理氨氮质量浓度为7 500 mg/L的联碱厂碳化塔洗水，氨氮的利用率为97.4%，制备的磷酸铵镁产物晶形比较规则，呈斜立方正交结构。1 t氨氮质量浓度为7 500 mg/L的联碱厂碳化塔洗水可生产磷酸铵镁0.139 2 t，产品收益约为320.2 元，药剂成本为352.3 元，即废水的处理费用约为32.1 元/t。

Preparation of Magnesium Ammonium Phosphate from Cleaning Water of Carbonization Tower in Hou’s Process

Magnesium ammonium phosphate was prepared by chemical precipitation process using the simulated cleaning water of carbonization tower in Hou’ process as raw material. The crystal form and composition of the product were analyzed by SEM and XRD. The suitable reaction conditions determined by orthogonal tests and single factor optimization tests are as follows：reaction pH 9.5,n(Mg)∶n(P)∶n(N)=1.2∶1.1∶1.0,reaction temperature 25 ℃. When the cleaning water of carbonization tower with 7 500 mg/L of ammonia nitrogen mass concentration is treated under these conditions,the utilization rate of ammonia nitrogen is 97.4%,and the crystal form of the product is regular with oblique cuboidal shape and orthogonal structure. 0.139 2 t magnesium ammonium phosphate can be produced from 1 t cleaning water with 7 500 mg/L of ammonia nitrogen mass concentration, the product profit is 320.2 yuan/t,the reagent cost is 352.3 yuan/t,therefore the treatment cost of the wastewater is about 32.1 yuan/t.