磷石膏一步法制取硫酸钾研究

发布时间：2018-02-22 16:32

  本文关键词： 磷石膏 硫酸钾 一步法 氨水 乙醇　出处：《昆明理工大学》2011年硕士论文　论文类型：学位论文

【摘要】：针对氨溶液中磷石膏制备硫酸钾工艺(正在研究,并无生产,只有方法)存在的问题,一些有机溶剂的加入能改善反应体系状态,从而促进反应的进行,考察了向反应体系中添加不同有机溶剂(甲醇、乙醇等11种不同的有机溶剂)对氧化钾收率的影响。根据不同溶剂及其浓度对氧化钾收率影响的实验结果初步筛选出甲醇、乙醇、正丙醇、异丙醇和丙酮这五种对提高氧化钾收率影响较大的溶剂。 筛选出来的甲醇等五种对氧化钾收率影响较好的溶剂分别与氨形成混合溶剂。考察了混合溶剂体系下对氧化钾收率影响较大的5种主要影响因素。结果表明,氨-乙醇混合溶剂最佳,氨-乙醇溶液体系有利于工艺条件的改善,能有效的提高氧化钾收率。 对氨-乙醇溶液中磷石膏直接制备硫酸钾的工艺进行了进一步的研究。其优化后的适宜工艺条件为：乙醇浓度为8%、氨初始浓度为25%、反应时间为1.0h、液固比为5.5：1、物料配比为1.20：1。 在上述实验条件下,反应的氧化钾收率可以达到75%左右,其中产品中氧化钾含量在40%左右,氯离子含量为1.74-1.85%。产品硫酸钾质量达到国家农业合格品,副产品氯化钙达到工业合格品。母液中的乙醇可于90℃的条件下蒸馏回收,回收率可达85%。
[Abstract]:In view of the problems existing in the process of preparing potassium sulfate from phosphogypsum in ammonia solution (no production, only method), the addition of some organic solvents can improve the state of the reaction system and thus promote the reaction. The effect of adding different organic solvents (methanol, ethanol, 11 different organic solvents) to the reaction system on the yield of potassium oxide was investigated. According to the experimental results of different solvents and their concentration on the yield of potassium oxide, methanol was preliminarily selected. Ethanol, n-propanol, isopropanol and acetone are the five solvents which have great influence on the yield of potassium oxide. Five kinds of solvents, such as methanol, which have a better effect on the yield of potassium oxide, are mixed with ammonia to form a mixed solvent. The five main factors which have a great influence on the yield of potassium oxide in mixed solvent system are investigated. The results show that, The ammonia-ethanol solution system is beneficial to the improvement of the process conditions and the yield of potassium oxide. The process of direct preparation of potassium sulfate from phosphogypsum in ammonia-ethanol solution was further studied. The optimum technological conditions were as follows: ethanol concentration 8, ammonia initial concentration 25, reaction time 1.0 h, liquid-solid ratio 5.5: 1, material ratio 1.20: 1. Under the above experimental conditions, the yield of potassium oxide can reach about 75%, in which the content of potassium oxide in the product is about 40%, the content of chlorine ion is 1.74-1.85. The by-product calcium chloride reached the industrial standard. The ethanol in the mother liquor could be distilled and recovered at 90 鈩，

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