本文選題：廢舊印刷線路板　切入點：細菌浸出液　出處：《西南科技大學》2016年碩士論文

【摘要】：利用細菌浸出的生物濕法冶金技術,實現(xiàn)了將廢舊印刷線路板(Waste Printed Circuit Boards)變成富含各種金屬離子的生物浸出液,對生物浸出液中的金屬進行回收,同時實現(xiàn)含重金屬廢水的處理與回用,成為了近年來WPCBs金屬資源化利用研究的熱點。本文以人工配制的硫酸銅溶液、廢舊印刷線路板的化學酸浸液和生物浸出液為研究對象,利用電沉積的方法回收生物浸出液中的金屬銅,探討了影響銅沉積的主要因素,獲取并優(yōu)化了金屬銅高回收率的關鍵技術參數(shù),得到結果如下:(1)通過對化學酸浸液和配制硫酸銅溶液的電沉積試驗對比,系統(tǒng)考察電沉積過程中電流密度、電解液pH值和溶液中其它金屬離子對電沉積效果的影響。當初始銅離子濃度為4.00 g·L-1、6.00 g·L-1時,陰極電流效率僅僅在前30 min達到90%,繼續(xù)電沉積,陰極電流效率下降明顯,120 min時陰極電流效率不足20%,電解槽陰極析氫現(xiàn)象明顯;在pH值2.0-4.0范圍內(nèi),提高初始pH值能顯著降低Fe3+的濃度,有利于銅的沉積,但過高的pH可能導致Cu2+的沉淀和吸附反應;優(yōu)化沉積條件(銅離子濃度9.75 g·L-1、pH=3.00、電流密度200 A·m-2)對化學酸浸液和配制硫酸銅溶液電沉積180 min后,銅回收率分別達到92.24%、89.41%,陰極電流效率分別為71.01%、62.84%。結果表明:用電沉積的方法能夠?qū)︺~進行有效回收,增加初始銅離子濃度會顯著提升陰極電流效率;銅回收率隨電流密度的增大而逐漸上升,但陰極電流效率會有所下降;酸浸液中雜質(zhì)金屬離子對銅回收有明顯抑制作用,主要表現(xiàn)在Fe3+對Cu2+的競爭還原。(2)探討影響WPCBs細菌浸出液中銅回收的因素及電沉積條件優(yōu)化。對WPCBs細菌浸出液去除部分有機物后,電沉積120 min后,銅回收率、陰極回收效率分別達到90.41%、92.14%。對比發(fā)現(xiàn),當電沉積過程中當銅回收率達到90%左右時,經(jīng)過臭氧氧化處理的細菌電解液陰極電流效率達到92.14%,明顯高于未經(jīng)處理的細菌浸出液(68.23%)。在電流密度200 A·m-2,pH=3.00,常溫條件下沉積180 min,在電沉積前期90 min時,銅回收率達到77.04%,高于酸浸液(67.66%),陰極電流效率基本保持90%以上且陰極沉積銅純度較高。結果表明:有機物含量對銅回收率、陰極電流效率有較為明顯的影響,去除有機物后銅回收率、陰極回收效率明顯提升;優(yōu)化電沉積條件,細菌浸出液的沉積效果較酸浸液好。
[Abstract]:The waste Printed Circuit boards were transformed into bioleaching solution rich in various metal ions, and the metals in the bioleaching solution were recovered by the biological hydrometallurgy technology of bacteria leaching, the waste printed circuit board (PCB) waste Printed Circuit Boardswere transformed into bioleaching solution rich in all kinds of metal ions, and the metal in the bioleaching solution was recovered. At the same time, the treatment and reuse of wastewater containing heavy metals has become a hot spot in the research of metal resource utilization of WPCBs in recent years. In this paper, the artificial copper sulfate solution, the chemical acid leaching solution of waste printed circuit board and the biological leachate are taken as the research objects. Using electrodeposition to recover metal copper from bioleaching solution, the main factors affecting copper deposition were discussed, and the key technical parameters of high recovery rate of metal copper were obtained and optimized. The results are as follows: (1) by comparing the electrodeposition test of chemical acid leaching solution with that of copper sulfate solution, the electric current density during electrodeposition is systematically investigated. The effect of pH value of electrolyte and other metal ions in solution on the electrodeposition effect. When the initial concentration of copper ion is 4.00 g / L ~ (-1) and 6.00 g ~ (-1) g 路L ~ (-1), the cathodic current efficiency is only 90 g 路L ~ (-1) at the first 30 min. The cathodic current efficiency is less than 20 when the cathodic current efficiency is decreased significantly (120 min), and the phenomenon of cathode hydrogen evolution is obvious in the electrolytic cell. In the range of pH 2.0-4.0, increasing initial pH value can significantly reduce the concentration of Fe3, which is beneficial to copper deposition. However, too high pH may lead to the precipitation and adsorption reaction of Cu2, and the optimum deposition conditions (copper ion concentration 9.75g / L ~ (-1) pH ~ (3.00), current density 200A ~ (-2)) were optimized for 180 min after electrodeposition of chemical acid leaching solution and preparation of copper sulfate solution. The recovery rate of copper is 92.240.89.41, and the cathodic current efficiency is 71.01and 62.84.The results show that the electrodeposition method can effectively recover copper and increase the initial concentration of copper ions can significantly improve the cathodic current efficiency. The recovery rate of copper increases gradually with the increase of current density, but the cathodic current efficiency decreases, and the impurity metal ions in the acid leachate can obviously inhibit the recovery of copper. The factors affecting the recovery of copper from WPCBs bacterial leachate and the optimization of electrodeposition conditions were discussed. After removing some organic matter from WPCBs bacterial leachate, copper recovery rate was obtained after electrodeposition for 120 min. The cathodic recovery efficiency reached 90.41% and 92.14% respectively. The results showed that when copper recovery reached 90% during electrodeposition, The cathodic current efficiency of bacterial electrolyte treated by ozone oxidation was 92.14%, which was significantly higher than that of untreated bacterial leachate (68.23%). At the current density of 200A m ~ (-2) and pH ~ (3. 00) at room temperature, the cathode current efficiency of bacterial electrolyte deposited at room temperature was 180 mins and 90 min during the early stage of electrodeposition. The recovery rate of copper is 77.04, which is higher than that of acid leaching solution 67.66%, the cathodic current efficiency is above 90% and the purity of cathode deposited copper is high. The results show that the organic content has obvious influence on the recovery rate and cathodic current efficiency of copper. After removing organic matter, the recovery rate of copper and the efficiency of cathodic recovery were improved obviously, and the deposition effect of bacterial leachate was better than that of acid leaching solution by optimizing the electrodeposition conditions.
【學位授予單位】：西南科技大學
【學位級別】：碩士
【學位授予年份】：2016
【分類號】：TF811;X705
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本文編號：1669250