盐酸法制备饲料级磷酸氢钙联产氯化铵工艺研究

发布时间：2018-06-22 22:59

本文选题：饲料级磷酸氢钙 + 脱氟　；参考：《河北科技大学》2015年硕士论文

【摘要】：盐酸法制备饲料级磷酸氢钙工艺由于具有磷收率高、可使用低品位磷矿、可使用市场上的副产盐酸及能耗低等优点,具有广阔的应用前景。本论文使用氯碱工业副产盐酸(质量分数约为21%)分解磷矿制备湿法磷酸,系统的研究了盐酸用量,反应时间,反应温度对萃取过程的影响,得到了较优工艺条件为:盐酸用量为1.05倍理论用量;反应温度为35℃;反应时间为0.5 h,在此条件下经计算可得萃取率为99.02%。我国的磷矿一般氟含量较高,但国家标准要求饲料级磷酸氢钙中的氟含量不得超过0.18%,因此除氟显得尤为关键。脱氟过程使用氯化钠、氯化钾、碳酸钠、氢氧化钙、碳酸钙做脱氟剂,结果表明氢氧化钙脱氟效果较好。设计了二次循环萃取无脱氟工艺路线,最终确定循环过程中液固比为2.15,此时的萃取率可达到95%左右。该工艺省去了脱氟过程,减少了原材料的消耗。中和结晶过程采用石灰乳、碳酸钙作为中和剂,并进行了分段中和结晶实验,结果表明分段中和结晶效果最好,得到的磷酸氢钙结晶颗粒较大,且较均匀。在氯化钙废液中加入碳化剂联产碳酸钙和氯化铵,控制反应条件,得到了符合国家标准的碳酸钙和氯化铵产品。
[Abstract]:The preparation of feed grade calcium hydrogen phosphate by hydrochloric acid method has the advantages of high phosphorus yield and low grade phosphate ore. It can use the byproduct of hydrochloric acid and low energy consumption in the market. It has a broad application prospect. In this paper, hydrochloric acid is prepared by decomposition of hydrochloric acid (mass fraction of about 21%) in chlor alkali industry, and the amount of hydrochloric acid is studied systematically. The effect of reaction time and reaction temperature on the extraction process has been obtained. The optimum technological conditions are as follows: the amount of hydrochloric acid is 1.05 times the theoretical dosage, the reaction temperature is 35, and the reaction time is 0.5 h. Under this condition, the extraction rate is 99.02%., the general fluorine content in the phosphate rock in China is higher, but the national standard requires fluorine in the feed grade calcium hydrogen phosphate. Not more than 0.18%, so the removal of fluorine is particularly critical. Defluorination process uses sodium chloride, potassium chloride, sodium carbonate, calcium hydroxide, calcium carbonate as defluorination agent. The result shows that the defluorination effect of calcium hydroxide is better. Two cycles of circulating extraction without defluorination are designed, and the ratio of liquid to solid in the cycle process is 2.15, and the extraction rate can reach 9 at this time. About 5%. The process saves the defluorination process and reduces the consumption of raw materials. Lime milk and calcium carbonate are used as neutralizer in neutralization crystallization process. The results show that the results of subsection neutralization and crystallization are best, and the crystalline particles of calcium hydrogen phosphate are larger and more uniform. The addition of carbonation agent in the waste liquid of calcium chloride is combined. Calcium carbonate and ammonium chloride were used to control the reaction conditions, and calcium carbonate and ammonium chloride products conforming to the national standard were obtained.
【学位授予单位】：河北科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ132.32

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