氰化尾渣还原焙烧酸浸提铁及氰化浸金新工艺

以氰化尾渣为原料,采用还原焙烧酸浸工艺对其进行处理。当还原温度为850℃、加入煤粉质量为氰化尾渣质量的13%、还原时间为100 min时,对氰化尾渣进行还原,氰化尾渣中Fe2O3转化为Fe3O4或FeO。还原后采用硫酸浸出,当硫酸浓度为50%、硫酸用量系数为1.2、反应温度为105℃、反应时间为3 h时,铁的浸出率达到93.66%。还原焙烧渣在600℃氧化焙烧2 h经过脱碳后氰化浸金,当氰化钠用量为4 kg/t、反应时间为28 h、液固比为2:1时,金的浸出率达到92.4%。经过还原焙烧、硫酸浸出、氧化焙烧及氰化浸金,氰化尾渣渣量减少了38.8%。     

某金铁氧化矿中矿泥对氰化浸出影响的研究

考察了高岭土、绿泥石、白云石和褐铁矿4种常见易泥化矿物对氰化浸出过程的影响,发现褐铁矿和白云石在细磨时形成的次生矿泥比原生矿泥具有更强的吸附已溶金能力,使浸出率降低。研究了原矿经粗磨-磁选后易泥化矿物的分布,对云南某金铁氧化矿采用"粗磨-分类磁选-分组氰化浸出"的新工艺,有效减少了次生矿泥的生成,与"细磨-氰化浸出-磁选"的传统工艺相比,金浸出率由85.26%提高到93.05%,铁精矿回收率由41.20%提高到70.86%。     

氰化浸出、氨预处理及氨氰浸出法处理富铜金矿（英文）

采用直接氰化浸出、氨预处理及氨氰浸出等方法处理含硫化铜的金矿。研究这些浸出体系中金和铜的溶解行为。当NaCN含量小于5g/L时,金的氰化浸出受到所含硫化铜的严重干扰,这与组分平衡计算结果一致。氨预处理可以消除铜的干扰,在后续的氰化浸出过程中,即使在剂量较小的情况下,金也可以获得较高的提取率。采用Box-Behnken试验设计研究了氨氰体系中NH3、NaCN和Pb(NO3)2的主要影响以及其相互作用。其中NH3和NaCN浓度是影响金提取率的主要因素,而Pb(NO3)2的影响有限。增加NH3的浓度可以提高金提取的选择性和提取率,同时降低氰化物的用量。统计研究结果表明试剂间的相互作用对金提取无重大影响。氨预处理和氨氰浸出法在含硫化铜的金矿的处理中具有广阔的应用前景。     

高岭石对氰化浸金的影响及助浸研究

采用电化学实验研究了在氰化浸金过程中常见矿物高岭石对金溶解速率及对溶液中金的吸附效果的影响。结果表明,高岭石的存在会使金的溶解速率加快,随着高岭石粒度逐渐降低金的溶解速率提高,且高岭石对溶液中金的吸附率增加。氰化浸出实验结果表明,高岭石存在时金的浸出率由93.21%降低到91.76%,采用柠檬酸三钠、过氧化镁和十二烷基硫酸钠助浸时,金浸出率升高至94.42%。能谱分析(EDS)发现浸出物中高岭石表面有金元素存在,表明高岭石会吸附溶液中的金。红外光谱分析和密度泛函理论计算表明,高岭石与金发生化学吸附作用,氢原子为高岭石的活性位点,C6H5O7^3-会优先吸附于高岭石(001)表面,加入助浸剂可降低高岭石与金的吸附强度,提高金的浸出率。     

锌粉置换镓锗渣高压酸浸的浸出机理

研究锌粉置换镓锗渣的高压酸浸过程,考察硫酸浓度、液固比、浸出时间、浸出温度、助浸剂种类和添加量对Ga、Ge浸出率以及浸出渣过滤性能的影响。结果表明:增加硫酸浓度有利于Ga、Ge的浸出,但硫酸浓度超过156 g/L后,反而不利于Ge的浸出。浸出时间和温度对Ga、Ge浸出率影响较小,但增加浸出时间或提高反应温度均有利于改善浸出渣的过滤性能。添加硝酸钠或硝酸钙均可促进Ga、Ge的浸出,且硝酸钙的添加还可改善浸出渣的过滤性能。在硫酸浓度156 g/L、助浸剂硝酸钙60 g/L、液固比8、浸出温度150℃下浸出3 h,Ga、Ge浸出率可分别达到98%和94%以上,且浸出料浆过滤速度较常压酸浸时的提高近20倍。     

某难选金矿加温化学预氧化浸出技术

以某实际含铜金矿为研究对象,在氯盐酸性加温体系下,分析浸出温度、时间、矿物粒度、NaCl浓度、H2SO4浓度、氧气流量等因素对化学预氧化浸出除铜和浸出渣氰化浸金的影响过程.结果表明:在90%矿样粒度小于37 μm、浸出温度95 ℃、初始H2SO4浓度0.75 mol/L、起始NaCl浓度0.7 mol/L、液固比5-1、浸出时间24 h、搅拌速度750 r/min的条件下,可使铜的浸出去除率达到80%以上,预氧化渣金的氰化浸出率达98.23%.     

选冶联合流程回收铜银金的工艺

采用ＤＸ 低碱度抑制剂， 用ＮａＯＨ 调节ｐＨ， 在ｐＨ＝ ９ ～１０ 的范围内浮铜抑硫， 使混合精矿中的有价金属与黄铁矿分离， 再选精矿产率２０ ％ ～３０ ％ ， 尾矿含金低于３ ．０ ｇ／ｔ。在较低的压力下（ 氧压０ ．４ ～０ ．６ ＭＰａ） 对所得精矿进行氧压氨浸， 使硫转化为硫酸铵， 铜进入溶液， 金银留在浸渣中。分选中金、银、铜回收率分别为９５ ％ ，９０ ％ 和８５ ％ ； 分选条件为ｐＨ＝ ９ ．５ ， 捕收剂用量２００ ｇ／ｔ， ＤＸ 抑制剂３ｋｇ／ｔ。低压氨浸铜浸出率为９５ ％ ， 浸出压力０ ．５ ＭＰａ， 温度１２０ ℃， 时间３ ｈ ， 氨浓度４５ ｇ／Ｌ。氰化浸出金、银浸出率为９７ ％ 和９５ ％ ， 置换率９９ ％ 和９８ ％ 。金、银、铜总回收率分别为９４ ％ ，８４ ％ 和８１ ％ 。     

加压碱浸处理氰化浸出法回收汽车废催化剂中的贵金属

为提高铂族金属的浸出回收率,针对前期研究提出的汽车废催化剂先经加压碱浸处理而后再加压氰化浸出铂族金属的新工艺,变动预处理反应过程各种工艺参数,考察了对后续铂族金属氰化浸出指标的影响。结果表明:预处理可打开汽车废催化剂载体对铂族金属的包裹,有利于其氰化浸出;但物料粒度过细或反应碱用量过大、温度过高、时间过长均容易形成新相重新包裹,不利于氰化试剂与铂族金属有效接触;预处理渣进一步湿磨,可消除包裹,提高氰化浸出率;在实验最佳条件下,铂族金属氰化浸出率分别可达到:Pt 96%、Pd 98%、Rh92%。     

不同含砷类型金矿的细菌氧化-氰化浸出

对含砷类型不同的金精矿和单矿物进行细菌氧化-氰化浸出研究,分析毒砂和雄黄对金精矿细菌氧化-氰化浸出效果的影响。结果表明:在细菌氧化过程中,含砷金精矿中的毒砂易被氧化分解,经过192 h的细菌氧化后,脱砷率可达93.10%;而雄黄无法被细菌氧化分解,且影响细菌活性,延长浸矿的停滞期;在氰化浸出过程中,毒砂非常稳定,不参与任何副反应;而雄黄易与CN-及保护碱发生副反应,且产生的沉淀物质会在金粒表面形成薄膜,从而降低氰化浸出效率。     

压缩空气加过氧化钙在金氰化中的协同作用

研究了湖南某金矿氰化浸金工艺，结果表明，通压缩空气同时添加过氧化钙的浸金效果比单一效果好，提高Ａｕ的浸出速度和浸出率，并降低过氧化钙的用量。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

The Mirror with Patterns of Auspicious Animals and Grapes——Exquisite cast mirror and the technology of surface tin-enrichment by rubbing-in and infiltration of tin-rich powder

<正>Bronze mirrors were used by the Chinese people before the introduction of the glass mirror.Only after it was replaced by the glass mirror did the bronze mirror gradually retreat from people's lives.Different styles of bronze mirrors were made in different historical periods,particularly in the Warring States Period,the Han and Tang Dynasties,which were the three peaks of the development of bronze mirror arts in ancient China.The casting techniques were exquisite.The surface of the bronze mirror was smooth and bright enough to reflect one's image,and there were scarcely any casting defects on the mirror surface.On the back of the bronze mirror,there were rich depictions of Arts and Humanities,and the ornamentations were also     

The 9th China International Diecasting Congress & Exhibition

The 9th China International Diecasting Congress ＆ Exhibition was held on July 22-24, 2014 at Shanghai New International Expc Centre. This exhibition was the most successful over the years, with over 6890 visitors and 155 exhibitors, and the exhibition area increased by 30% from 9,500 square meters in 2012 to 12340 square meters. Die casting enterprises from a total of 24 countries and regions, including China mainland, Chinese Taiwan and Hong Kong, South Korea, Japan, Germany, India, Thailand, Malaysia, the United States, Russia, Australia, Iran, Ukraine, Brazil, Colombia, Singapore, Austria, Canada, Croatia, France, Turkey, United Kingdom, Vietnam, attended the congress and exhibition.     

Introduction of the Fluid Control Engineering Institute of Kunming University of Science and Technology

正The Fluid Control Engineering Institute of Kunming University of Science and Technology was set up in 1996.The researches of institute concentrate on electro-hydraulic(pneumatic)servo/proportional control and hydromechatronics.The Institute is committed to research and development of electro-hydraulic control of high-end technical equipment in ferrous metallurgy refining produc-     

RARE METALS Volume Contents

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Antimony Induced Crystallization of Amorphous Silicon

Antimony induced crystallization of PVD (physics vapor deposition) amorphous silicon can be observed on sapphire substrates. Very large crystalline regions up to several tens of micrometers can be formed. The Si diffraction patterns of the area of crystallization can be observed with TEM (transmission electron microscopy). Only a few and much smaller crystals of the order of 1μm were formed when the antimony layer was deposited by MBE (molecular beam epitaxy) compared with a layer formed by thermal evaporation. The use of high vacuum is essential in order to observe any Sb induced crystallization at all. In addition it is necessary to take measures to limit the evaporation of the antimony.     

A CUMULATIVE FATIGUE DAMAGE RULE UNDER THE ALTERNATIVE OF CORROSION OR CYCLIC LOADING

Fatigue damage increases with the applied loading cycles in a cumulative manner and the material deteriorates with the corrosion time. A cumulative fatigue damage rule under the alternative of corrosion or cyclic loading was proposed. The specimens of aluminum alloy LY12-CZ soaked in corrosive liquid for different times were tested under the constant amplitude cyclic loading to obtain S-N curves. The test was carried out to verify the proposed cumulative fatigue damage rule under the different combinations among corrosion time, loading level, and the cycle numbers. It was shown that the predicted residual fatigue lives showed a good agreement with the experimental results and the proposed rule was simple and can be easily adopted.