六十年代初,弗赖堡选矿研究所曾在膦酸类中,探寻到含有锡石有效捕收剂的化合物。许多矿床的锡矿石,用膦酸浮选得到了良好结果。近年来,继续对膦酸类做了系统的研究,特别注意了适于工业运用的那些膦酸。对于其他的含磷有机化合物(磷酸、膦酸、焦磷酸、次膦酸、复杂的磷酸单酯和磷酸二酯)对锡矿石的捕收性能,也进行了试验。同膦酸类相反,亚磷酸和次膦酸类是一元酸。曾经用各种烷基、芳基化合物和烷基苯化合物进行试验,由于未表现出任何捕收作用或仅有微弱作用,停止了进一步的研究。焦膦酸是膦酸这类有效捕收剂的衍生物,通过将相应的两个膦酸分子缩合成焦膦酸,达到增强捕收能 In the early 1960s, the Freiburg Mineral Processing Institute explored phosphonates and found compounds that contain an effective cassiterite collector. Many deposits of tin ore, with phosphonic acid flotation get good results. In recent years, systematic studies of phosphonic acids have continued, paying particular attention to those phosphonic acids that are suitable for industrial use. Other phosphorus-containing organic compounds (phosphoric acid, phosphonic acid, pyrophosphoric acid, phosphinic acid, complex phosphoric monoesters and phosphoric acid diesters) were also tested for tin ore collection performance. In contrast to phosphonates, phosphites and phosphinates are monobasic. Experiments with a variety of alkyl, aryl and alkylbenzene compounds have been conducted and no further studies have been stopped as no catching effect or only a weak effect has been demonstrated. Pyrophosphoric acid is a derivative of such an effective collector as phosphonic acid, which achieves enhanced trapping energy by condensation of the corresponding two phosphonic acid molecules into the phosphonic acid