摘要
随着光伏组件大规模退役期的到来,其资源化处理成为推动光伏产业全生命周期绿色发展的关键。为实现铝、银、硅等高价值材料的高效回收,提出“热处理+三级湿法分步浸出”联合工艺。退役晶硅电池片经机械破碎与800℃热处理后,依次进行三级浸出:一级盐酸/硫酸溶出铝、二级硝酸提取银、三级氢氟酸去除Si3N4减反射层并提纯硅。研究系统考察了酸种类、质量分数、反应时间、液固比和温度等参数对各阶段浸出行为的影响。结果表明,一级浸出在质量分数10%HCl、液固比5∶1 mL/g、50℃、30 min条件下,铝浸出率超过80%,银浸出率低于3%,展现出良好的铝选择性。提高HCl浓度或采用质量分数60%H2SO4虽可提升铝浸出率至94%以上,但银溶解显著增加,且高浓度硫酸易引发操作问题。二级浸出中,低浓度硝酸(质量分数15%)因减轻铝表面钝化银,浸出性能相对较高;提高液固比至8∶1 mL/g可促进银溶解,而温度升高至70℃则因硝酸挥发导致浸出率下降。三级浸出在质量分数5%HF、25℃、50 min、液固比5∶1 mL/g条件下,可有效去除减反射层,获得纯度超过60%的硅粉;HF体系对反应时间和温度敏感,低温有利于减少挥发,延长反应时间显著提升硅含量。该分级浸出工艺充分利用铝、银、Si_(3)N_(4)在不同酸介质中的反应活性差异,实现了多组分的顺序.分离与富集,显著提高了试剂利用效率,减少了强酸消耗与废液排放。与直接单步湿法处理相比,本工艺在铝/银选择性、硅回收纯度及环境友好性方面优势明显,为退役晶硅光伏组件的高值化回收与工业化应用提供了可靠的技术路径。
With the advent of the large-scale decommissioning period of photovoltaic modules,their resource treatment has become key to promoting the green development of the photovoltaic industry throughout its entire life cycle.To achieve efficient recovery of high-value materials such as aluminum,silver,and silicon,this study proposes a combined process of“thermal treatment+three-stage wet stepwise leaching”.Retired crystalline silicon cells were mechanically crushed and thermally treated at 800℃,followed by a three-stage leaching process:primary leaching with hydrochloric acid/sulfuric acid to dissolve aluminum,secondary leaching with nitric acid to extract silver,and tertiary leaching with hydrofluoric acid to remove the Si3N4 anti-reflection layer and purify silicon.The study systematically investigated the effects of parameters such as acid type,concentration,reaction time,liquid-solid ratio,and temperature on the leaching behavior at each stage.The results showed that under the conditions of HCl with mass fraction 10%,a liquid-solid ratio of 5∶1 mL/g,50℃,and 30 min,the primary leaching achieved an aluminum leaching rate exceeding 80%,with a silver leaching rate below 3%,demonstrating good selectivity for aluminum.Increasing the HCl concentration or using H2SO4 with mass fraction 60%could increase the aluminum leaching rate to over 94%,but silver dissolution significantly increased,and the high concentration of sulfuric acid easily caused operational issues.In the secondary leaching,low-concentration nitric acid(mass fraction 15%)showed relatively high silver leaching performance due to reduced aluminum surface passivation;increasing the liquid-solid ratio to 8∶1 mL/g promoted silver dissolution,while raising the temperature to 70℃decreased the leaching rate due to nitric acid volatilization.In the tertiary leaching,under the conditions of HF with mass fraction 5%,25℃,50 min,and a liquid-solid ratio of 5∶1 mL/g,the anti-reflection layer was effectively removed,yielding silicon powder with a purity exceeding 60%;the HF system was sensitive to reaction time and temperature,with lower temperatures favoring reduced volatilization and extended reaction time significantly increasing silicon content.This stepwise leaching process fully utilizes the differences in reactivity of aluminum,silver,and Si_(3)N_(4) in different acid media,achieving sequential separation and enrichment of multiple components,significantly improving reagent utilization efficiency,and reducing the consumption of strong acids and waste liquid discharge.Compared to direct single-step wet processing,this process demonstrates clear advantages in aluminum/silver selectivity,silicon recovery purity,and environmental friendliness,providing a reliable technical pathway for the high-value recycling and industrial application of decommissioned crystalline silicon photovoltaic modules.
作者
白冰
陈佩
邢楠
张敏
蒲京
张乾生
胡中发
王学斌
BAI Bing;CHEN Pei;XING Nan;ZHANG Min;PU Jing;ZHANG Qiansheng;HU Zhongfa;WANG Xuebin(CGN Environmental Technology Co.,Ltd.,Shenzhen 518031,China;MOE Key Laboratory of Thermo-Fluid Science and Engineering,Xi’an Jiaotong University,Xi’an 710049,China;School of Energy,Soochow University,Suzhou 215006,China)
出处
《洁净煤技术》
北大核心
2025年第11期197-208,共12页
Clean Coal Technology
基金
国家重点研发计划资助项目(2024YFE0111000)
国家自然科学基金资助项目(52376125)
深圳市科技研发基金资助项目(KCXST20221021111212029)。
关键词
退役晶硅光伏组件
热处理
太阳能电池片
酸浸
retired crystalline silicon photovoltaic modules
heat treatment
solar cells
acid etching
