Tin-containing slag from pyrometallurgical recovery process of spent lead-acid battery is a valuable secondary Sn resource. However, the low content of Sn (~4 wt%) in this slag with complex impurities (Fe, Al, Pb, Zn, and Cu, etc.) makes it challenging for efficient tin separation. In this study, a low-temperature chlorinating process is proposed for tin recovery from the tin-containing slag by using ammonium chloride as the chlorinating reagent. Under the optimized chlorinating conditions, tin volatilization ratios of above 96% under both air and vacuum atmospheres could be achieved. However, the discrepancy between the temperatures of tin chlorinating and impurity metal chlorinating is more dramatic under the air atmosphere than that under vacuum, which facilitates the separation of impurities. Meanwhile, the decomposition rate of NH₄Cl in air is much lower than that under vacuum atmosphere, resulting in less consumption of NH₄Cl. The obtained chlorinated condensation product in air is subjected to a subsequent water leaching-alkali smelting-leaching-crystallization process to effectively separate Fe impurity and obtain the final sodium stannate product with a total tin recovery ratio of 94%. This study provides a promising strategy for the recovery of tin, and significant environmental benefit could be generated simultaneously with solid waste recycling.

废铅酸电池火法回收过程中的含锡矿渣是宝贵的二次锡资源。但是，这种炉渣中的Sn（〜4 wt％）含量低，带有复杂的杂质（Fe，Al，Pb，Zn和Cu等），这对有效分离锡具有挑战性。在这项研究中，提出了一种低温氯化工艺，通过使用氯化铵作为氯化试剂从含锡矿渣中回收锡。在优化的氯化条件下，在空气和真空气氛下锡的挥发率均可以达到96％以上。但是，在空气中，锡氯化和杂质金属氯化的温度之间的差异比在真空下的差异更为显着，这有利于杂质的分离。同时，NH的分解率空气中的₄ Cl远低于真空环境下的₄ Cl ，从而减少了NH ₄ Cl的消耗。将获得的空气中的氯化缩合产物进行后续的水浸-碱熔-浸-析结晶过程，以有效地分离出Fe杂质，得到最终的锡酸钠产物，总锡回收率为94％。这项研究为锡的回收提供了一种有希望的策略，并且在回收固体废物的同时还可以产生巨大的环境效益。