以荧石氟化钙（ＣａＦ２）或者磷肥厂尾气用水吸收的含氟化氢（４．０４ｍｏｌ／Ｌ）的废水为原料，在常温常压下合成氟化氢铵ＮＨ４ＨＦ２。经测定０８０３ｍｏｌ的ＮＨ３与０８４６ｍｏｌＣａＦ２制得的Ｈ２Ｆ２（０８ｍｏｌ）可以完全反应，制得含０６６５ｍｏｌＮＨ４ＨＦ２的溶液，收率为８３２％。该溶液对织物有明显的除锈退色作用，性能优于普通除锈剂草酸或氟化钠溶液。当ＮＨ４ＨＦ２的浓度为０９１８ｍｏｌ／Ｌ时，对白色织物上的深棕色锈斑退色效率可达８５％以上，比同浓度的氟化钠和草酸溶液分别提高１５％和２０％相对标准 Ammonium bifluoride (NH4HF2) was synthesized from waste water containing hydrogen fluoride (4.04 mol / L) absorbed by the fluorite calcium fluoride (CaF2) or the tail gas from the phosphate fertilizer plant. After the determination of 0  803mol of NH3 and 0  846molCaF2 prepared H2F2 (0  8mol) can be completely reacted to prepare a solution containing 0  665molNH4HF2, the yield was 83  2%. The solution has obvious rust and fading effect on the fabric, and the performance is better than that of ordinary rust remover oxalic acid or sodium fluoride solution. When the concentration of NH4HF2 is 0918mol / L, the dark brown rust stain on the white fabric can reach more than 85%, which is 15% and 20% higher than the same concentration of sodium fluoride and oxalic acid respectively