羟基乙叉二膦酸(HEDP),具有良好的化学稳定性,能耐高温,兼有缓蚀和阻垢等特点,广泛用于循环冷却水、锅炉水、油田注水及输油管线防腐蚀、防垢等方面,而且也常用作金属离子的掩蔽剂、萃取剂等。根据合成工艺路线,产品中的主要杂质有磷酸和亚磷酸,它们的离解常数(分别为K_1=7.5×10~(-3)、K_2=6.2×10~(-8)和K_1=1.0×10~(-2)、 Hydroxy ethylidene diphosphonic acid (HEDP), with good chemical stability, high temperature resistance, both corrosion and scale inhibition and other characteristics, is widely used in circulating cooling water, boiler water, oil field pipelines and pipeline corrosion, anti-scale And so on, but also commonly used as metal ion masking agent, extractant and so on. According to the synthetic route, the main impurities in the product are phosphoric acid and phosphorous acid, and their dissociation constants (K_1 = 7.5 × 10 -3, K_2 = 6.2 × 10 -8 and K_1 = 1.0 × 10 ~ (-2),