Department of Chemistry of Xiangtan University, Xiangtan 411105, PR China.
Department of Environment and Resources, Xiangtan University, Xiangtan 411105, PR China.
Waste Manag. 2022 Jan 1;137:319-328. doi: 10.1016/j.wasman.2021.11.011. Epub 2021 Nov 24.
The traditional sodium desulfurization process for waste lead-acid batteries is beneficial to the environment; however, it is limited by poor economic viability as the cost of desulfurizer is much higher than the value of desulfurization by-products. This study proposes a new closed-loop pre-desulfurization process for lead paste, which consumes only lime as the indirect desulfurizer, produces sodium sulfate as a by-product, and regenerates sodium hydroxide as the direct desulfurizer. The concentration of prepared sodium hydroxide reached 2.57 mol/L when the reaction was conducted at room temperature for 2.0 h, with a sodium oxalate: calcium oxide molar ratio of 1:1.3, a CaO: water mass ratio of 1:6, and magnetic stirring at 600 rpm. Cost estimation and economic analyses were also conducted. The cost of lead paste generated by this new pre-desulfurization process was 37.62 dollars/ton lower than traditional high-temperature smelting, and 44.42 dollars/ton lower than direct sodium pre-desulfurization. Thus, this process provides a practical and feasible clean recycling method for waste lead-acid batteries with significant environmental and economic benefits.
传统的废铅酸电池钠脱硫工艺有利于环境，但由于脱硫剂成本远高于脱硫副产物的价值，其经济可行性较差。本研究提出了一种新的铅膏闭路预脱硫工艺，该工艺仅使用石灰作为间接脱硫剂，生成硫酸钠作为副产物，并再生氢氧化钠作为直接脱硫剂。当在室温下反应 2.0 h 时，反应产物中氢氧化钠的浓度达到 2.57 mol/L，草酸鈉与氧化鈣的摩尔比为 1:1.3，氧化钙与水的质量比为 1:6，在 600 rpm 的磁搅拌下进行反应。同时进行了成本估算和经济分析。与传统的高温熔炼相比，这种新的预脱硫工艺生产的铅膏成本每吨降低了 37.62 美元，与直接的钠预脱硫相比，每吨降低了 44.42 美元。因此，该工艺为废铅酸电池的清洁回收提供了一种实用可行的方法，具有显著的环境和经济效益。
