关键词: 真空蒸馏, 含锡磷铁, 脱锡率, 蒸馏温度, 蒸馏时间

Abstract: This study investigates the effects of distillation temperature and time on the tin removal rate from ferrophosphorus during vacuum distillation, based on vacuum distillation separation theory.Theoretical analysis demonstrates that the majority of tin could be effectively separated from ferrophosphorus materials by controlling appropriate distillation temperature and vacuum pressure. Taking tin-rich ferrophosphorus materials as the experimental raw materials and a vacuum induction melting furnace as the separation equipment, the vacuum distillation experiments were carried out at a vacuum of 10 Pa to explore the effects of temperature and time on tin separation performance. The experimental results showed that the tin removal rate increased rapidly with the rise of temperature and reached the maximum value above 1873 K, and higher temperatures barely contributed to extra tin removal. At 1823 K, appropriately extending the distillation time was conducive to enhancing the tin removal rate, while extending the distillation time at 1873 K exerted little promoting effect on tin removal. Through process optimization, the optimal distillation process parameters were determined as follows: a vacuum pressure of 10 Pa, distillation temperature of 1873 K, and distillation time of 60 min. Under this condition, the tin removal rate reached 99.6%, and the Sn mass fraction in condensate reached approximately 90.5wt%. The theoretically calculated optimal distillation temperature was 1820 K, which deviated from the experimental optimal value. Such discrepancy was mainly attributed to the reduced activity coefficients caused by impurity elements in the actual system, which endowed the molten system with non-ideal solution characteristics.

Key words: vacuum distillation, tin-containing ferrophosphorus, tin removal rate, distillation temperature, distillation time