硫酸盐体系非均匀电场提镉工艺研究

以铜镉渣浸出液为原料,首先考察均匀电场和非均匀电场对提取金属镉的影响,再对非均匀电场的提镉工艺进行研究。单因素法获得非均匀电场提镉最佳工艺条件是：电流密度200 A/m²、温度40℃、脉冲占空比30%、溶液pH=3.0、电源频率200 Hz、反应时间2.5 h。最后,在不同温度和不同溶液pH下,对镉锌硫酸盐溶液进行循环伏安扫描,探究锌置换提取镉的阳极反应机理。结果表明,升高温度能促进镉的还原析出,减小pH不利于锌对镉的置换反应。铜镉渣浸出液中镉的提取回收对实现镉的源头减排与污染控制有重大意义。     

高镉烟尘氧化酸浸试验

采用氧化酸浸法从高镉烟尘中高效浸出锌、镉,研究了过氧化氢用量、浸出温度、浸出时间、液固比及硫酸浓度对锌、镉浸出率的影响。结果表明,在硫酸浓度50 g/L、过氧化氢用量60 g/L、液固比3 mL/g、浸出温度80 ℃、浸出时间2.0 h的条件下,锌、镉浸出率分别可达93.50 %、95.97 %。     

低品位铅冰铜硫酸氧化浸出动力学

采用H₂SO₄-H₂O₂体系对低品位铅冰铜进行了氧化浸出研究,利用ICP、XRF、粒度分析、XRD和SEM-EDS等手段对铅冰铜进行了物质组成研究,并分析了浸出动力学过程。结果表明：在初始硫酸浓度210 g/L、浸出温度70℃、搅拌速度400 r/min、过氧化氢与铅冰铜的质量比5、浸出时间180 min和液固比11的条件下,铜浸出率可达90.69%。动力学分析表明,低品位铅冰铜的硫酸氧化浸出过程符合未反应收缩核模型,反应活化能为9.67 kJ/mol,浸出过程受扩散控制。     

载镉废啤酒酵母中金属镉的回收

以水洗废啤酒酵母为吸附剂,对废水中镉离子进行生物吸附及固液分离后,获得载镉废啤酒酵母。采用焙烧-酸浸-置换法回收"载镉菌体上的镉",在700℃焙烧24 h,菌渣中镉富集比为31.72,烧渣经15 g/L的硫酸、温度85℃条件下,浸出2 h,再用锌粒置换,得海绵镉,镉总回收率在98%以上。     

废触媒浸出液中铁镍合金的电沉积

以人造金刚石废触媒的硫酸浸出液为基础,采用L₁₆(4⁵)正交试验方案,在1 200 C恒定通电量下,进行直流静态电解沉积Fe-Ni合金,研究了各工艺参数对电沉积电流效率、镀层镍质量分数,以及Ni、Fe析出的分电流密度的影响规律,并以电流效率为主要指标优化得出最优工艺参数。结果表明,对电流效率影响因素由大到小的顺序为镀液pH>电流密度>温度>糖精钠浓度>硫脲浓度。最优工艺参数为平均电流密度500 A/m²、温度45℃、pH=3.55、糖精钠浓度3 g/L、硫脲浓度0.15 g/L。最优条件验证试验结果表明了正交试验结果的可靠性。     

从钴渣中浸出钴、锌、镉试验研究

研究了采用水洗—焙烧—还原酸浸工艺从A药剂钴渣中高效回收钴等有价金属,考察了焙烧温度、浸出时间、浸出温度、硫酸浓度、还原剂用量等对有价金属浸出率的影响。结果表明:钴渣在液固体积质量比5/1、常温下搅拌水洗1 h,然后在500℃下焙烧2 h,最后在80℃下用质量浓度80 g/L硫酸、10 g/L亚硫酸钠浸出1 h,钴浸出率在90%以上,锌浸出率在96%以上,镉浸出率大于99%,浸出液中的有价金属可高效回收。     

核桃壳还原浸出软锰矿的动力学

探究以核桃壳为还原剂硫酸浸出氧化锰矿过程的动力学。考察了搅拌速度、反应温度、硫酸浓度、反应时间以及核桃壳用量对锰浸出率的影响。结果表明,锰的浸出率随着搅拌速度、硫酸浓度、核桃壳用量的增大和温度的升高而增大。浸出前60 min浸出率的增长速度较快。在反应温度为369 K、硫酸浓度3.5 mol/L、核桃壳加入量40 g/L、反应时间2.5 h、转速200 r/min时,锰浸出率达93.18%。浸出过程属于化学反应控制,对应的活化能为45.5 kJ/mol,硫酸浓度和核桃壳用量的反应级数分别为0.897、0.2。     

铅冶炼烟尘浸出液中镉的电积行为的规律

镉常伴生于锌矿、铅锌矿和铜铅锌矿石中,约95%的镉作为铅锌冶炼过程中的副产品被回收,其中冶炼烟灰是镉回收的主要原料之一。本文以铅冶炼烟尘为对象,研究了其硫酸浸出液中镉的电解沉积行为,主要考察了电流密度、温度以及镉离子的浓度对电流效率、单位电耗、阴极镉纯度及形貌的影响规律。结果表明:在电流密度150 A/m2、温度30 ℃、浸出液中镉浓度40 g/L的条件下,电沉积4 h的电流效率可达96.14%,单位电耗为1.769 kW·h/kg,阴极镉的纯度可达到97.75%。升高温度、增大电流密度、镉离子的消耗都在不同程度上降低了电流效率并增加了单位电耗。电极反应动力学表明,镉离子在阴极区的还原过程受离子扩散控制。      

超声辅助电积法回收铜镉渣中镉、锌的试验研究

采用电积置换法回收铜镉渣中镉时,电积过程会产生漂浮海绵镉,导致镉回收效率低,且不利于后续的压团冶炼。本文在分析镉电积的原理基础上,利用超声波的空化作用,进行了超声波辅助镉电积试验,考察了电流密度、温度、超声功率、阴阳极面积比和电积时间等因素对镉回收率的影响,得到以下主要结论。循环伏安测试结果表明,在硫酸盐体系中,电积可将电解液中的镉置换出来,且镉优于锌先电积析出,随着电积的进行,镉外层的锌会部分返溶;有无超声波辅助的镉电积对比试验表明,无超声波辅助时镉回收率为16.25%,且电积出的镉组织蓬松、孔隙多,易漂浮,180 W超声波辅助下镉回收率为25.11%,且电积出的金属镉致密,易掉落;单因素试验结果表明,在电流密度150 A/m²、温度35℃、超声功率240 W、阴阳极板面积比1∶3、电积时间2.5 h条件下,浸出液中镉回收率能达到100%;不同温度的电化学试验表明,温度升高有利于镉的析出,而且析出的金属锌易被氧化溶解,金属镉难被氧化溶解,从而提高镉的回收率和纯度。     

蔗糖还原浸出锰阳极泥中锰的研究

采用蔗糖还原浸出阳极泥中的锰,通过正交实验和单因素实验,探讨了搅拌速率、液固比、反应温度、反应时间、硫酸浓度、蔗糖浓度等因素对阳极泥锰浸出率的影响,正交实验表明,各因素影响锰浸出率的大小顺序为:硫酸浓度蔗糖浓度浸出温度浸出时间。较优的工艺条件为:硫酸浓度3.5 mol/L,蔗糖浓度70 g/L,液固比为4∶1,搅拌速率100 r/min,反应温度70℃,反应时间40 min,锰浸出率达到98%。     

熔炼次数对M17返回料合金成分、组织和性能的影响

实验结果表明,M17铸造高温合金(%:0.16C、8.79Cr、5.79A1、4.93Ti、3.29Mo、15.20Co、0.78V、0.015B、0.073Zr、0.002S、0.001P、0.001 1O、0.001 0N)经25 kg真空感应炉返回重熔后,Si含量随重熔次数的增加而略有增加,合金中主要元素和其它杂质元素S、P、H的含量变化不大,而氧、氮略有增加;合金中初生碳化物由新合金中的草书体逐渐向返回合金块状转变,初生碳化物的遗传性堵塞合金凝固时的补缩通道,使返回料合金的疏松倾向增大,高温塑性下降较大。     

China's Major Non-ferrous Metals Imports & Exports

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Zinc Production by Province in 2014

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80% of Chinese Firms Purchasing Overseas Mines Ended up in the Red

<正>Minmetals Resources acquired the world’s largest copper mine under construction for USD5.85 billion.One after another,listed companies Jien Nickle,China Molybdenum and Chihong Zinc and Germanium raised money to get involved in overseas mining projects…SOEs and private enterprises are engaged in a frenzy of overseas mine purchasing.A reporter with Economic     

Copper Processing Profit Dropped Sharply,Copper Consumption Will Face Impact in the Second Half of the Year

正Judging from China’s copper consumption field,the biggest consumption unit is electric power,which accounts for 47%of total consumption;it is followed by light industry sector,including household electrical appliance,machinery,durable goods and hardware etc,which accounts for 22%of total consumption;followed by transportation field,     

Central Geological Prospecting Fund Newly Added 16.47 Million Tonnes of Bauxite in 2013

正In 2013,the Central Geological Prospecting Fund(CGPF)Project newly discovered 15 ore fields,including 3 large above ore fields,and 5medium sized ore fields.The reporter learned from the recently published"Annual Report of Central Geological Prospecting Fund Project(2013)"that,from 2006 to 2013 the CGPF     

Manufacturers of Copper Tube for Central Air Conditioner Use Face Mounting Pressure in the Final Quarter of the Year

正This year,the investment growth rate of real estate industry continued to slow down,sold area of commercial housing also dropped significantly,which brought huge pressure to the domestic air conditioning manufactures.In the first half of the year,by relying on high growth in national financial expenditure,along with investment in public infrastructure     

Xinjiang Ranks No.1 in Production of Primary Aluminum in China

正Kang Yi,Honorary Chairman of China Nonferrous Metals Industry Association,said recently at the Forum on Development of the Non-ferrous Metals Industry in Central and Western China held in Zhengzhou that,as more and more electrolytic aluminum factories in Xinjiang came into operation,the electrolytic aluminum output of Xinjiang had reached2,275,000 tons in the first 7 months this year,     

Shenhuo Coal Industry and Electricity Power Completed800,000 t/a Aluminum Project in Xinjiang

正"Xinjiang project has been completed according to schedule,but total completion and total start of production are two different concepts,after completion it still needs a gradual process of reaching production target."On the morning of November 3,Shenhuo Coal Industry and Electricity Power told investors the above statement on the investor interaction platform.     

Guangdong Metal Transaction Center has Become the Second Largest Precious Metal Transaction Platform Nationwide

正The reporter learned from Guangdong Province Precious Metal Transaction Center that in 2013the Center maintained healthy development momentum,and had become the second largest precious metal transaction platform in China in terms of market size;currently Guangdong is quickening steps of financial innovation for the Center,aiming to build a transaction center with international core competitiveness.