【作者】 李伟；

【导师】 丘克强；

【作者基本信息】 中南大学 ， 冶金工程， 2013， 硕士

【摘要】 锡阳极泥和锡烟尘是两种重要的锡二次资源,是锡循环工业中的重要环节。充分利用这两种二次资源,符合我国发展循环经济和建立资源节约型社会的要求。随着国家“绿色发展”理念的提出,针对这类二次资源开发清洁高效的回收新工艺具有重要意义。针对锡阳极泥的物料特征,并通过理论分析,提出了真空的方法对该阳极泥进行回收。通过两步真空碳热还原工艺,将阳极泥中铅锑复合氧化物还原并分解为PbO和Sb203后迅速挥发除去,同时脱除铅和锑；进一步还原蒸余物以回收粗锡；采用真空蒸发的方法分离冷凝物中的铅和锑。实验结果表明,在还原剂用量为4%,空气流量为400mL/min的条件下,将阳极泥在1123K下进行真空碳热还原处理60min后,铅的脱除率为99.58%,锑的脱除率为92.85%。蒸余物在还原温度为1173K,还原剂用量为12.5%,体系压强为40-400Pa的条件下进行真空还原60min后,回收得到纯度为94.22%的粗锡,锡的直收率为94.35%。冷凝物在温度为923K,体系压强为40Pa的条件下进行真空蒸发60min后,铅和锑得到较好的分离。与传统工艺相比,真空回收锡阳极泥的方法具有流程简单,能耗及成本低,无烟气污染、回收效率高等优点。采用真空蒸发的方法进行了锡烟尘的脱砷预处理,考察了蒸发温度、蒸发时间和体系压强等因素对烟尘蒸发率的影响。实验结果表明,当蒸发温度为673K,蒸发时间为30min,体系压强为40Pa时,烟尘蒸发率为16.2%,蒸余物中砷含量降至1.12%,砷的脱除率达92.7%,为锡烟尘循环利用创造了良好的条件。更多还原

【Abstract】 As two important secondary resources, tin anode slime and tin dust are both crucial parts of tin circular industry. It is very necessary to take full advantage of these two secondary resources to conform to the requirements of developing circular economy and building resource-conserving society in China. It is also of great significance to develop cleaner and more efficient process for recovering such secondary resources as the concept of "Green Development" was advocated in our country.In this work, a vacuum process was proposed for recovering tin anode slime, on the basis of the material characteristic of the tin anode slime to be processed and theoretical analysis. During two-step vacuum carbothermal reduction, the antimony and lead were removed simultaneously by reducing and decomposing the mixed oxide of lead and antimony into PbO and Sb2O3, crude tin was recovered by the reduction of the distilland. The lead and antimony in the distillate were separated mutually via vacuum evaporation. The results showed that99.58%by weight of lead and92.85%by weight of antimony could be removed at1123K for60min with4%of reductant and air flow rate at400mL/min. The crude tin with a tin content of94.22%was obtained via vacuum carbothemal reduction of the distilland under the following conditions:temperature of1173K, time of60min, reductant dosage of12.5%and system pressure of40～400Pa. Correspondingly, the direct recovery ratio of tin was94.35%. The lead and antimony in the distillate could be separated well by vacuum evaporation at the temperature of923K for60min with a system pressure of40Pa. The vacuum method for the treating tin anode slime has such features, as simple process flow, low energy consumption and cost, no smoke pollution and high recovery efficiency, when compared with the traditional process.Vacuum evaporation was developed as a clean pretreatment method of remove arsenic from tin dust. The dependence of evaporation ratio of tin dust on experimental conditions including evaporation temperature, evaporation time and system pressure was investigated. The results showed that92.7%of arsenic was removed when the evaporation experiment was conducted at temperature of673K for30min with a system pressure of40Pa, the corresponding evaporation ratio was16.2%. The content of arsenic in the distilland could be reduced to1.12%, which was very beneficial to the recycling of tin dust.更多还原