Hydrometallurgical route normally has lower energy consumption and less carbon dioxide emission than high-temperature smelting route. However, efficient removal of impurities is a common challenge for hydrometallurgical process. A facile recovery route of spent lead-acid battery pastes, including efficient desulfurization and pH-controlled acid leaching, is proposed. Effects of two typical desulfurizers (NaOH and Na₂CO₃) on desulfurization efficiency and removals of major impurities (Ba and Fe elements) were comparatively investigated for the first time. NaOH was more effective than Na₂CO₃ with a higher desulfurization efficiency of 99.3 wt% in 10 min. Approximately 26.2 wt% of BaSO₄ in the raw spent lead paste was converted into BaCO₃ in the Na₂CO₃ desulfurization system, causing more Ba element entered into the acid leaching solution. The significant decrease of pH in the acid leaching solution caused a high concentration of Fe element impurity, which was efficiently removed by further pH adjustment. The optimal conditions were determined to be: a NaOH/PbSO₄ molar ratio of 2.0 in the desulfurization step, a HNO₃/Pb molar ratio of 2.2 in the acid leaching step, and followed by adjusting the pH of the acid leaching solution to about 3.48. Up to 98.4 wt% of the Pb was recovered, while 99.8 wt% of Ba and 99.9 wt% of Fe element impurities were removed. The obtained low-impurity lead nitrate solution was further converted into high-purity PbCO₃ and α-PbO products, providing a viable alternative for the recovery of the spent lead pastes.

湿法冶金路线通常比高温冶炼路线具有更低的能耗和更少的二氧化碳排放。然而，有效去除杂质是湿法冶金工艺的普遍挑战。提出了一种简便的回收废铅酸电池浆料的途径，包括有效的脱硫和pH控制的酸浸。首次比较研究了两种典型的脱硫剂（NaOH和Na ₂ CO ₃）对脱硫效率和去除主要杂质（Ba和Fe元素）的影响。NaOH比Na ₂ CO ₃更有效，在10分钟内的脱硫效率高达99.3 wt％。约26.2 wt％的BaSO ₄在Na ₂ CO ₃脱硫系统中，废铅浆中的Ba转变为BaCO ₃，导致更多的Ba元素进入酸浸液中。酸浸溶液中pH的显着降低导致高浓度的Fe元素杂质，可通过进一步的pH调节将其有效去除。确定最佳条件为：脱硫步骤中的NaOH / PbSO ₄摩尔比为2.0，HNO ₃/ Pb摩尔比在酸浸步骤中为2.2，然后将酸浸溶液的pH调节至约3.48。回收了高达98.4 wt％的Pb，同时去除了99.8 wt％的Ba和99.9 wt％的Fe元素杂质。将获得的低杂质硝酸铅溶液进一步转化为高纯度PbCO ₃和α-PbO产品，为回收废铅膏提供了可行的替代方法。