磷酸淤渣综合利用的基础研究

发布时间：2017-12-27 19:03

本文关键词：磷酸淤渣综合利用的基础研究　出处：《昆明理工大学》2016年硕士论文　论文类型：学位论文

【摘要】：磷矿石及其经过加工生产的磷酸等产品在农业、食品和工业等领域中广泛应用。我国的磷矿石的总储量位居世界第二位,资源丰富、储量较大,令人担忧的是我国的磷矿石有80%以上都属于中低品位矿。随着工农业的发展和磷矿资源的逐渐开发,我国的磷矿储量在逐渐的减少,特别是高品位磷矿储量,所以我国应该重视和提高磷矿石资源的综合利用,满足可持续发展理念。磷酸淤渣是硫酸分解磷矿石制备湿法磷酸生产过程中主要的固体废弃物,它是一种很好的二次资源,所含的主要化学成分有磷、钙、铁、镁、铝等元素,可用于提取磷、铁等有价元素,用来制备较高附加值的产品。使固体废物得到综合利用,对促进磷资源的二次开发利用和经济的高速发展具有重要的意义。通过化学的分析方法得到了处理后磷酸淤渣中磷元素含量为22.07%,铁元素的含量为15.07%。通过探讨盐酸、硝酸、硫酸3种不同浸取剂对磷酸淤渣原料的浸取效果的影响,本实验选用了硫酸作为浸取剂。研究表明,采用硫酸浸出磷酸淤渣的优化工艺条件为：液固比(mL/g)为3：1,硫酸质量分数为25%,搅拌速度为300r/min,反应时间为60min,反应温度为80℃,洗涤水用量为40mL/次,洗涤3次。浸出液作为净化阶段的原料液,其中磷含量为32.0469g/L,铁含量为21.8790g/L,经过净化脱硫实验,得到的净化液中磷含量为22.1139g/L,铁含量为16.4790g/L。净化过程中脱硫率为91.39%。优化的净化脱硫工艺条件：浸出液取200mL,搅拌速度为350r/min,静置时间为80min,反应温度为60 ℃, Ca(OH)2加入量为24g,反应时间为70min。经过净化脱硫实验,得到的净化液作为制备磷酸铁的原料液,其中磷含量为22.1139g/L,铁含量为16.4790g/L。通过调节溶液pH值可制备磷酸铁,溶液中的铁回收率达到99.35%。制备磷酸铁后,滤液中的磷含量为2.6896g/L,因此,滤液可以进一步制备其他含磷产品,如磷酸钠盐、磷酸铵盐等工业级产品,或循环利用,以提高浸出液中磷资源的综合利用率。制备磷酸铁的优化工艺条件：pH值为2.0,反应温度为90℃,搅拌速度为350r/min,洗涤水用量每次为30mL,洗涤3次,反应时间为60min。
[Abstract]:Phosphate rock and its processed phosphoric acid are widely used in the fields of agriculture, food and industry. The total reserves of phosphate rock in China ranks second in the world, with abundant resources and large reserves. It is worrying that more than 80% of phosphate rock in China belongs to medium and low grade ores. With the development of industry and agriculture and the gradual development of phosphate resources, the reserves of phosphate rock in China are gradually decreasing, especially the reserves of high-grade phosphate ore. Therefore, we should pay more attention to the comprehensive utilization of phosphate ore resources and satisfy the concept of sustainable development. Phosphoric acid sludge is a solid waste sulfuric acid decomposition of phosphate rock is mainly prepared by wet process phosphoric acid production process, it is a good two resources, the main chemical composition contained elements of phosphorus, calcium, iron, magnesium, aluminum, etc., can be used for the extraction of phosphorus, iron and other valuable elements, used in the preparation of high value-added products. The comprehensive utilization of solid waste is of great significance for the two development and utilization of phosphorus resources and the rapid development of the economy. The phosphorus content in the phosphoric acid residue was 22.07% and the iron content was 15.07% after the chemical analysis. By discussing the effect of 3 different leaching agents of hydrochloric acid, nitric acid and sulfuric acid on the leaching effect of phosphoric acid sludge, sulphuric acid is selected as the leaching agent. The research shows that the optimum process conditions for sulfuric acid leaching of phosphoric sludge are: liquid solid ratio (mL/g) is 3:1, sulfuric acid mass fraction is 25%, stirring speed is 300r/min, reaction time is 60min, reaction temperature is 80 degrees, washing water volume is 40mL/ times, washing time is 3 times. The leaching solution is used as raw material for purification phase. Phosphorus content is 32.0469g/L and iron content is 21.8790g/L. After purification and desulfurization experiments, the content of phosphorus in purification fluid is 22.1139g/L and iron content is 16.4790g/L. The desulphurization rate in the process of purification is 91.39%. The optimized purification and desulphurization conditions were as follows: extraction of 200mL from leaching solution, stirring speed of 350r/min, static time of 80min, reaction temperature of 60 C, Ca (OH) 2 of 24g and reaction time of 70min. After the purification and desulphurization experiment, the purified liquid was obtained as the raw material for the preparation of iron phosphate, of which the content of phosphorus was 22.1139g/L and the iron content was 16.4790g/L. Iron phosphate can be prepared by adjusting the pH value of the solution, and the recovery of iron in the solution is 99.35%. After the preparation of ferric phosphate, the phosphorus content in the filtrate is 2.6896g/L. Therefore, filtrate can further prepare other industrial products such as sodium phosphate, ammonium phosphate and other industrial products such as sodium phosphate and ammonium phosphate, or recycle them, so as to improve the comprehensive utilization rate of phosphorus resources in leaching solution. The optimum process conditions for preparing ferric phosphate are: pH value is 2, reaction temperature is 90 centigrade, stirring speed is 350r/min, washing water volume is 30mL per time, washing time is 3 times, reaction time is 60min.
【学位授予单位】：昆明理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：X781.3;TQ126.35

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