混合酸溶液浸出刚玉烟尘灰中的镓（英文）

为了从高硅含量的刚玉冶炼烟尘中提取镓,提出一种硫酸与氢氟酸混合酸溶液浸出的方法,并对浸出过程的各项实验参数进行优化。结果显示,当单独使用硫酸作为浸出剂时,刚玉烟尘中镓的浸出率仅为38%。从刚玉烟尘灰的微区成分分析结果中可知,烟尘中的富硅相镓含量较高;这部分镓无法溶入硫酸溶液。氢氟酸的加入对二氧化硅产生侵蚀,从而显著提高了刚玉烟尘灰中镓的浸出率。研究反应时间、温度、氢氟酸浓度和硫酸浓度对镓浸出率的影响。结果表明,在最佳浸出条件下,烟尘中镓的浸出率可达到91%。最佳的浸出参数如下:反应时间4 h、反应温度80°C、混合酸溶液中硫酸浓度1.5 mol/L、氢氟酸浓度6.4 mol/L和液固比5:1 (mL/g)。     

镓精矿中镓的提取工艺

采用"焙烧-硫酸浸出-中和沉淀"工艺提取明矾石精矿中的镓,获得含Ga 0.1%以上的镓精矿。为了实现镓精矿的高值化利用,提出"碱浸-离子交换-溶液净化-电积"回收镓精矿中金属镓的工艺,对最佳工艺条件进行研究。在最佳工艺条件下,镓精矿中Ga的碱浸浸出率达98.46%;离子交换实验表明,采用D5240树脂可以有效地富集镓,但杂质钒也得到富集,树脂解吸液中含镓2.1g/L,钒0.23g/L;在pH=12的条件下,可通过钙盐法除钒,当解吸液中Ca~(2+)添加量为0.02mol/L时,钒浓度降至1.45mg/L;镓电积过程中电流效率呈现先增大后减小的趋势,当电积时间为2h时,电流效率达到峰值4.3%;随着电积液中NaOH浓度的升高,阴极表面形貌由粗糙变得光滑。当NaOH浓度为200g/L时,阴极表面平整光滑,可获得99.94%金属镓。     

水热活化法对粉煤灰中镓浸出效果的影响研究

为了提高粉煤灰的综合利用价值,利用水热活化法对烧结处理的粉煤灰进行酸浸实验,分别探讨了烧结过程中烧结温度、烧结时间以及酸浸过程中浸取液酸度、液固比、温度和时间等因素对粉煤灰中镓的浸出效果的影响。实验结果表明:当烧结温度为800℃、烧结时间为2 h、浸取液酸度为6 mol/L、液固比为15:1(m L:g)、浸取温度为140℃、浸取时间为2 h,粉煤灰中镓的浸出率为89.7%。     

微波碱溶法对粉煤灰中镓浸出效果的影响研究

采用微波碱溶法浸取焙烧处理的粉煤灰,研究了烧结温度、烧结时间、添加剂比例、微波反应温度、钙硅比、碱液浓度、液固比、微波反应时间等因素对镓溶出效果的影响。综合镓的溶出率以及反应成本等因素,确立了浸取镓的优化条件。试验结果表明:微波碱溶的最优条件应为烧结温度850℃、烧结时间2h、添加剂比例1∶1、反应温度为90℃、钙硅比为1∶1、碱液浓度为200 g/L、液固比为14∶1、反应时间为40 min。在优化条件下,粉煤灰中镓的浸出率可达82.28%。     

赤泥酸浸的试验研究

以HCl和H2SO4为浸出剂,对赤泥中各有价金属的浸出条件进行了较系统的试验研究。结果表明,先采取低浓度HCl浸出,残渣再用高浓度H2SO4分解的两段浸出方式为佳。一段浸取盐酸浓度为6mol／L．液固比L／S=4：1．反应温度50℃,反应时间1h。Sc2O3的浸出率大于80％,TiO2的浸出率为1％左右。二段浸取硫酸浓度为92％．酸渣比为3：1．熟化温度为200℃,熟化时间为1．5h。TiO2的浸出率为96．57％。     

基于隔膜电积的硫酸铅渣湿法提铅新工艺及电化学机理

根据物料平衡和电荷平衡原理,对Pb(Ⅱ)-Ac~--H~+-H_2O体系进行热力学分析,分析结果表明在接近于实际浸出液的pH值范围内,溶液中PbAc~+平衡浓度最高。以湿法炼锌产出的硫酸铅渣为原料,采用单因素实验法优化"乙酸盐配位浸出-隔膜电积提取铅"的主要工艺条件,采用单因素试验法优化乙酸铅溶液隔膜电积工艺条件,采用线性扫描、循环伏安等电化学测试手段研究Pb(Ⅱ)-Ac~--H_2O体系铅电积过程中阴极电化学行为。结果表明:在反应时间1h、浸出温度70℃、乙酸铵浓度4mol/L、液固比4:1的优化条件下浸出硫酸铅渣,铅浸出率93.28%。在电积温度30℃、Pb~(2+)浓度50 g/L、电流密度100 A/m~2的条件下阴极电流效率98%左右,每吨Pb直流电耗约700 kW·h。在此条件下以硫酸铅渣浸出液直接作为电积液隔膜电积8 h在阴极可以获得纯度99.2%较为致密平整的电铅,阴极电流效率96.16%。铅的还原沉积过程是一个不可逆过程,铅在电沉积初期遵循三维连续成核与颗粒长大机制,升高温度和提高阴极液Pb~(2+)浓度可以促进溶液离子扩散,提高电流效率。     

有机硅废触体中铜的高效提取及高纯铜制备EI北大核心CSCD

针对有机硅行业生产过程中产生的废触体,提出水浸预处理-氧化酸浸-旋流电积制备高纯铜的工艺。采用单因素实验法,分别考察反应温度、液固比、反应时间等因素对水浸预处理及氧化酸浸效果的影响。结果表明:在反应温度80℃、反应时间30 min、液固比3∶1 mL/g的优化条件下进行水浸预处理,处理后氯、铁的去除率可分别达到93.95%、5.25%,而铜不浸出;在双氧水用量为理论用量的2.0倍、反应温度为30℃、硫酸浓度为1.25 mol/L、液固比为3∶1 mL/g、反应时间为20 min的优化条件下,氧化酸浸过程中铜的浸出率可达93.59%,溶液中铁含量仅为0.25 g/L,且循环浸出时浸出率保持稳定。经循环浸出富集后的硫酸铜浸出液采用旋流电积制备高纯铜,得到的产品形貌平整,铜含量大于99.98%,达到GB/T467—2010的要求。     

矿浆电解法浸出广西某银矿粉中银的工艺条件研究

以广西某新开采的独立银矿的矿石所制得精矿粉为原料,加入适量软锰矿粉(MnO_2)和硫酸,在95℃下预处理2 h后,采用矿浆电解法,在自行研制的电解槽中进行单因素提取银的实验研究.在温度50℃,电流密度0.035 A/cm~2,液固比7:1,电解时间10h的电解条件下,银的浸出率可达95.9%.     

高硫砷金矿焙砂的硫酸熟化法预处理

基于氧化铁与硫酸反应的热力学原理,采用硫酸熟化-水浸法对高硫高砷金精矿氧化焙砂进行预处理,以脱除铁氧化物,破坏其对金的包裹,提高金浸出率。结果表明,在适宜的硫酸含量下,赤铁矿与硫酸反应的产物硫酸铁可转化为板铁矾HFe(SO4)2·4H2O晶体,降低了产物浓度,从而使赤铁矿继续溶解,提高了铁脱除率;适当升高温度可促进扩散的进行,从而使铁的脱除更加彻底。焙砂的氰化浸金率在脱除铁氧化物后显著提高。对于某铁含量为31.25%(质量分数)金含量为84.27 g/t的焙砂,当熟化条件为硫酸含量75%、硫酸过剩系数1.4、熟化温度250℃、熟化时间1 h时,焙砂中残余铁含量降至7.23%,此时金浸出率可达97.51%。     

复杂硫化铜矿热活化-加压浸出工艺

针对以黝铜矿为主体矿物的复杂硫化铜矿开展热活化-加压浸出工艺研究.结果表明:复杂铜精矿经573 K温度热活化1～2 h后,在浸出温度453 K,氧分压0.6 MPa,初始硫酸浓度1.23 mol/L,液固比5:1,木质素磺酸钙用量为精矿质量的1.25%等条件下,浸出仅2 h就可使铜和锌浸出率分别高达94.08%和96.95%,而铁浸出率仅为22.37%;在复杂铜精矿热活化预处理过程中,未见铅、锌、硫和砷等元素挥发损失,并探讨了复杂铜精矿的热活化机理.     

Recovery of gallium from phosphorus industry flue

The flue dust generated during electric furnace production of elemental phosphorus was investigated for the recovery of gallium. Then the flue dust was slurried with water and blended with concentrated sulfuric acid, followed by ageing. The gallium in the dust was thereby converted to soluble sulfate. The factors affecting the dust curing were investigated to understand the process chemistry of the pretreatment. The optimal curing conditions are determined as follows: the mass ratio of dust to water and acid is 1 : 1 : 1, ageing temperature and time are 200℃ and 2h, respectively. Almost all the gallium available to acid dissolution in the dust, about 90% gallium, can be extracted by leaching the cured dust at 80℃ for 1h.     

Leaching of gallium from corundum flue dust using mixed acid solution

In order to extract gallium from a high-silica-content flue dust generated in corundum production, a mixed acid solution of H₂SO₄ and HF was used for leaching, and test parameters of the leaching process were optimized. Experimental results show that the leaching rate of gallium was only 38% when H₂SO₄ was used as leaching agent. Composition analysis results of micro areas in this corundum flue dust indicate that the content of gallium in silica-enriched phases was high; this portion of gallium was insoluble in H₂SO₄ solution. The leaching rate of gallium increased significantly with addition of HF due to corrosion of silica. Effects of reaction time, temperature, and concentrations of HF and H₂SO₄ on leaching rates of gallium were investigated. The leaching rate of gallium reached 91% when this corundum flue dust was leached in a mixed acid solution of H₂SO₄ and HF for 4 h, at a temperature of 80 °C, with a liquid-to-solid ratio of 5:1 (mL/g). The optimal concentrations of H₂SO₄ and HF in the mixed acid solution were 1.5 and 6.4 mol/L, respectively.     

Processing to obtain high-purity gallium

Gallium has become increasingly popular as a substrate material for electronic devices. Aside from ore, gallium can be obtained from such industrial sources as the Bayer process caustic liquor that is a byproduct of bauxite processing, flue dust removed from the fume-collection system in plants that produce aluminum by the electrolytic process, zinc refinery residues, gallium scrap materials, and coal fly ash. The purification process for gallium can start with solvent-extraction processes where the concentrations of impurities, especially metals, are reduced to the ppm range. This article describes how ultra-purification techniques can be employed to reduce the undesirable impurities to the low ppb range. The various procedures described give an idea as to the extent of work needed to obtain and prepare high-purity gallium for electronic application. For more information, contact R.G. Bautista, University of Nevada, Department of Metallurgical and Materials Engineering, Reno, Nevada 89557; e-mail bautista@mines.unr.edu.     

大功率密闭直流电弧炉冶炼钛渣烟气净化工艺研究

根据国内引进的第一台30MW密闭直流电弧炉钛渣生产线的工艺流程,对采用云南省钛铁矿冶炼钛渣过程中产生的烟气进行了气体及烟尘的流量、含量、化学成分等分析。由于产生的烟气具有温度高、含尘量大(1.75%~9.60%)、SO2含量低、CO含量高的特点,选择烟气净化设备时,除了处理能力要符合生产要求,还需要考虑粉尘粒径和烟气温度这两个因素,以实现烟气回收利用的目的。经过研究,烟气净化工艺首先对烟气进行直接水冷使烟气降温,然后选用德国进口涤气机对烟气进行精处理,除尘效率可以达到99.983%。处理净化后的烟气,热值高,气体性质稳定,净化后可安全用于无烟煤/钛渣干燥及渣包/铁包的烘烤,实现节能减排的目标;烟尘可以回收利用。     

盐酸蒸馏-磷酸三丁酯萃取法从锗煤烟尘中综合回收锗和镓

先采用二氧化锰氧化-盐酸蒸馏提取煤烟尘中的锗,经提纯后制备得到高纯二氧化锗,同时煤烟尘中的镓在蒸馏过程中充分溶解到了锗蒸馏残渣液中,过滤后镓和蒸馏后残留的锗进入到了蒸馏残液中,调节蒸馏残液的酸度至5.6mol/L,采用磷酸三丁酯的260#溶剂油溶液对镓进行萃取,蒸馏残液中的少量锗亦被同时萃取进入到有机相中,用氢氧化钠溶液进行反萃取,反萃取完后调节pH至6.5~6.7,升温至85~95℃水解,得到氢氧化镓沉淀和二氧化锗沉淀,经过滤烘干后得到含锗镓精矿。锗的蒸馏回收率可达到92.37%以上,残液中锗的萃取率可达到86.18%以上;镓的盐酸浸出率可达81.23%以上,镓的磷酸三丁酯萃取率可达98.81%以上,反萃取率可达99.11%以上,中和沉淀直收率可达93.20%以上;工艺方法具有工艺流程简短、设备简单、过程易于控制,所用生产辅料较少,是一种从煤烟尘中综合回收锗和镓的高效且经济的方法。     

Purification technology of flue gas from remelting process of aluminum alloy tailings

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Chloride-process treatment of smelter flue dusts

A low-pressure, low-temperature chloride leach process called the Cashman process can be used to extract metals from arsenical flue dusts and residues and fix the arsenic in an environmentally stable form as ferric arsenate (scorodite). The process has been pilot tested in an integrated plant including continuous recycle; during the tests, several tonnes of flue dust were processed. Based on this pilot program, the process was deemed technically feasible, and its products are commercially salable. Residues from this pilot program were also subjected to a long-term stability test.     

高磷鲕状赤铁矿添加脱磷剂还原焙烧脱磷机理(英文)

高磷鲕状赤铁矿是一种典型的难处理铁矿石,采用常规的选矿方法难以得到较好的提铁降磷指标。采用添加脱磷剂还原焙烧,然后对焙烧产物进行两段磨矿磁选来处理此类矿石,获得了较好的选别指标。实验结果表明,铁的品位从43.65%(原矿)提高到90.23%(磁选精矿),磷含量从0.82%(原矿)降低到0.06%(磁选精矿),铁的回收率达到87%。采用XRD、SEM、EPMA等分析方法对焙烧产物进行脱磷机理研究。结果表明,在还原焙烧过程中,原矿中有20%的磷灰石生成单质磷随气体挥发,80%的磷灰石没有参与生成单质磷的反应,仍以磷灰石的物相存在于焙烧产物中,而通过磨矿磁选被脱除到尾矿中。磁选精矿中少量的磷以磷灰石的形态存在。在焙烧过程中,加入的脱磷剂与原矿中的脉石矿物(SiO2、Al2O3)反应生成铝硅酸钠,此反应部分破坏原矿的鲕状结构,充分改善焙烧产物中矿物的单体解离程度,有利于后续的磨矿磁选。     

不锈钢电弧炉粉尘直接还原回收工艺研究

电弧炉粉尘巳被列为有害废物，直接还原回收粉尘中有价金属不仅可保护环境，而且可充分利用宝贵的金属资源。采用中频感应电炉模拟电弧炉冶炼工艺进行了A、B、C和D系列实验研究。通过气体成分的检测、钢锭和炉渣的成分分析，了解工艺参数对还原过程的影响，认为电弧炉粉尘直接还原回收工艺切实可行，不影响钢产品质量，为该新工艺的生产实践提供了依据。     

Electrochemical corrosion of Ti6Al4V,Ti and AISI 316L SS after immersed in concentrated simulated body fluid

The biomimetic method is used to obtain hydroxyapatite (HAP) coatings on Ti6Al4V, Ti and AISI 316L SS substrates. These substrates with different pretreatment surface operations (HNO₃, anodic polarization, base-acid) were immersed in concentrated simulated body fluids (SBF) for different days at physiologic conditions of 37°C, initial pH of 7.4. Then the corrosion behaviours of substrates after immersion in concentrated SBF were examined by electrochemical methods in Ringer’s and 0.9 wt% NaCl solutions at a temperature of 37°C. Ions concentrations and pH analyses were carried out after incubation in concentrated SBF. After immersion in SBF for different days, the surface morphology remains almost unchanged and no apatite formation is observed. Corrosion currents of substrates increased after immersion. Ions concentrations and pH values were shown variability according to soaking time and pretreatment surface operations.