由磷肥企业副产氟硅酸制备氟化钠的研究

Study of Prepared the Sodium Fluoride from Fluosilicic Acid by Product of a Phosuhate Fertilizer Factory

重点介绍了以磷肥企业副产氟硅酸为原料制备氟化钠的新工艺。首先用氨水氨化脱硅得到氟化铵溶液,再向氟化铵溶液加氯化钠合成氟化钠。对影响反应的温度、时间、物料配比等因素进行了探讨,得出具体工艺为:(1)氨化反应:H2SiF6浓度在12%～14%之间,氨水过量25%,反应温度为60～70℃,反应时间120min。(2)氟化钠合成:氯化钠过量15%～20%,反应温度85～90℃。产物氟化钠纯度大于98%,收率大于80%。

This article introduce the new craft that prepared sodium fluoride from fluosilicic acid by product of a phosphate fertilizer factory.First the ammonium fluoride solution prepared by,desilica with ammonia,then ammonium fluoride solution reacting with sodium chloride to produce sodium fluoride.Factors such as reaction temperature,reaction time,ingredient ratio and so on influence reaction is discussed.The idiographic procee condition： （1）aminate reaction： density of silicofluoric acid is 12%-14%,the excessive ratio of ammonia is 25%, reaction temperature is 60-70℃ ,reaction time is 120 minutes.（2）Synthesize sodium fluoride： the excessive ratio of sodium chloride is 15%-20% ,reaction temperature is 85-90 ℃.Purity of sodium fluoride 〉98% ,yield 〉80%.