废铅蓄电池胶泥低温熔盐熔炼热力学分析及试验验证  

Thermodynamic Calculation and Verification Experiments of Low-temperature Molten Salt Smelting of Spent Leadacid Battery Paste

作　　者：叶龙刚[1] 胡宇杰[1] 王宇菲[1] 阳海棠[1] 文平[1] 

机构地区：[1]湖南工业大学冶金工程学院,湖南株洲412007

出　　处：《金属材料与冶金工程》2015年第3期35-40,43,共7页Metal Materials and Metallurgy Engineering

基　　金：国家自然科学基金资助项目(51104182;51234009)

摘　　要：针对废铅酸蓄电池胶泥回收困难和硫酸厂及冶炼厂产出大量黄铁矿烧渣及次氧化锌烟灰利用的难题,提出了低温熔盐还原固硫熔炼。对熔炼体系进行了热力学分析,计算了在500-1 000℃温度下体系中各可能发生的反应的标准吉布斯自由能变化值（ΔGθT）,并绘制了相应的ΔGθT-T图。分析结果表明,在500-1000℃温度范围内,铁和锌的氧化物被还原成金属较难,PbSO4既可能与FeO和ZnO发生还原固硫反应生成FeS和ZnS,也很容易与Na2CO3发生反应生成Na2S,三个反应的ΔGθT都很负,但与ZnO、FeO反应的热力学趋势更大,生成的Na2S在有CO2存在的条件下也很容易被FeO和ZnO再生成Na2CO3。以Fe2O3和ZnO为固硫剂的验证试验中考察了温度对铅直收率和固硫率的影响,在温度达到850℃时,铅直收率和固硫剂都能分别达95%和90%以上,熔炼渣XRD分析显示其主要成分分别为Na Cl、Na FeS2、Na2CO3和NaCl、Na2CO3、ZnS,熔盐介质Na Cl-Na2CO3的主成分没有变化。In view of the difficulties in recycling of spent lead-acid battery paste and utilization of pyrite cinder and secondary Zn O ash generated in sulphuric acid plants and smeltries, a technique of reduction and sulfur-fixing smelting in low-temperature molten salt was proposed. A thermodynamic analysis was carried out on the smelting system. The values（ΔGT^θ） of Gibbs free energy changes of various probable reactions at the reaction temperature（ΔGT^θ-T） of500 ~1 000 ℃ were calculated and plotted. The results of thermodynamic analysis show that it is difficult to reduce the oxides of Zn and Fe into metals. Pb SO4 not only can react with both FeO and ZnO to produce Fe S and Zn S, respectively, but also can react with Na2CO3 to produceNa2S. The ΔGθTof the three reactions all are negative, but the reaction with Fe O and Zn O show a high thermodynamic tendency. However, the produced Na2 S can be regenerated into Na2CO3 by reacting with Fe O and Zn O in the presence of CO2. In conformation experiments, the effect of temperature on the direct recovery rate of Pb and sulfur-fixing rate were investigated in detail when FeO and ZnO were used as the sulfur-fixing agent. The recovery rate of Pb and sulfur-fixing rate were 95% and 90% respectively at the temperature of 850 ℃. The XRD analysis of the smelting slag show that the main compositions are NaCl, Na FeS2 and Na2CO3 and NaCl, Na2CO3 and Zn S, respectively. The main component of the molten salt medium did not change.

关 键 词：废铅蓄电池 低温熔盐 黄铁矿烧渣 次氧化锌烟灰 清洁冶金 

分 类 号：F426-32[经济管理—产业经济]