氰化厂浸金贫液除杂工艺生产实践

简要介绍了招远市罗山金矿氰化厂酸化－氧化净化浸贫液工艺，该工艺可将贫液中的铜，氰化物，铅，锌的含量分别降至1．5mg/L,0.5mg/L,1.0mg/L,1.0mg/L以下，满足了贫液返回使用的要求，另外，该工艺有效地回收利用了贫液中氰化物，取得了良好的环境效益，社会效益和经济效益。     

高钴硫酸锌溶液两段高温锑盐净化除钴的生产实践

介绍了两段高温锑盐净化工艺的基本原理,操作条件及生产实践。该工艺可将高钴硫酸锌溶液中的钴从60～90mg／L除至1mg/L以下。     

饮用水中有机氯化物高级氧化工艺去除特点及机理分析

采用O3,UV,UV/空气和UV/O3工艺对三氯甲烷和氯苯2种重要氯化物的去除效果进行了比较,并就UV/O3工艺对2种有机物去除机理展开分析.试验90 min时,UV(253.7 nm)工艺氯苯分解产物氯离子浓度为2.03 mg/L,UV(253.7 nm)/O3工艺为1.80 mg/L,150 min时二者分别为2.28和2.48 mg/L;不同初始浓度下,UV/O3工艺在2 h内对三氯甲烷的去除率均高于60%;2种试验条件下,UV/O3工艺对三氯甲烷去除率分别为55.6%和56.1%,UV/空气工艺则分别达到了48.9%和53.8%;UV/空气工艺静态试验中,随着三氯甲烷的去除,水中溶解氧浓度从初始的7.25 mg/L降低为1.28 mg/L.试验结果表明,UV/O3工艺去除有机物机理较为复杂,与目标有机物自身性质密切相关.     

改良型双污泥工艺处理低C/N城市污水

[目的]优化双污泥工艺存在的缺陷.[方法]采用改良型双污泥工艺处理人工配制模拟生活污水,测定处理前后水质并进行比较.[结果]系统出水COD<40mg/L、TN<15 mg/L、氨氮<3 mg/L、TP<0.5 mg/L,均达到了<城镇污水处理厂污染物排放标准>(GB18918-2002)的一级A 标准.[结论]改良型双污泥工艺不仅可以解决硝化细菌与除磷菌之间的泥龄矛盾问题,而且较适合处理低C/N条件下的城市污水.     

400系热轧铁素体不锈钢无氟酸洗工艺生产实践

针对400系热轧铁素体不锈钢常规酸洗工艺中存在的问题,引进无氟酸洗工艺,使得酸洗板表面粗糙度由3.4～3.5μm降低到≤2.9μm,盐雾试验防护评级由6级提高到5级,废酸中氟离子浓度由1 213 mg/L降到272.4 mg/L,刷洗水中氟离子浓度由352.2 mg/L降低到16.2 mg/L。400系铁素体不锈钢酸洗板质量得到了稳定提升,取得了较好的经济效益和环保效益。     

高含砷冶炼污酸单级硫化脱砷试验

硫化法是目前冶炼污酸除砷应用最广泛的方法。常规硫化法采用阶梯式硫化、多级硫化、高效硫化反应器等工艺,或产出大量危废渣且后液不能回用只能排放,或成本高、流程长,或对高含砷污酸处理效果不理想。对含砷16 060 mg/L、铜28.04 mg/L、铅9.80 mg/L的高含砷污酸的除杂工艺进行研究,考察了硫化钠（Na2S?9H2O）加入量、加入方式及时间、反应温度等因素对除杂效果的影响,确定了“硫化+絮凝”的工艺,通过优化药剂加入方式从而减少药剂加入量,探索出了最佳工艺控制条件,达到“流程短、加药精准、污染小”的目的。结果表明,污酸中的砷可降至0.23 mg/L甚至<0.1 mg/L,铅、铜分别降至<0.1 mg/L,远低于工业硫酸一级品的限值。     

造纸废水处理工艺研究

采用高速上流式厌氧污泥床反应器(HUASB)联合供气式低压射流(FAS-Jet)曝气氧化沟工艺处理造纸废水,对整个工艺及调试运行过程进行了详细介绍.实际运行结果表明,该工艺设计合理,运行稳定可靠,总排放口出水COD≤90 mg/L、SS≤30 mg/L、BOD5≤20mg/L,出水水质可达到<造纸工业水污染排放标准>(GB3544-2008)的要求.且该工艺基本达到封闭运行,实现了系统的零排放.     

铜矿矿山废水的物化净化处理研究

针对某铜矿矿山酸性废水与选矿废水的所形成的混合废水的pH值较低,COD及重金属离子浓度较高的特点,研究利用Fenton氧化-电石乳中和-絮凝联合工艺处理酸碱混合废水的效果,试验表明:联合工艺对废水中的COD和重金属有着较高的去除率,当双氧水、电石乳及PAM投加量分别为340mg/L、12g/L以及2mg/L时,废水经处理后,COD<100mg/L,重金属Zn2+、Cu2+无检出,总铁<0.1mg/L、总锰<0.1mg/L,出水达到国家《污水综合排放标准》(GB8978-1996)一级排放标准。     

高碳酸盐型铀矿床微酸中性地浸采铀试验

某砂岩铀矿碳酸盐含量高,为避免常规酸法或碱法地浸的化学堵塞,开展了微酸中性地浸试验。以0.3g/L的硫酸溶液为溶浸剂,双氧水、氧气为氧化剂。浸出体系pH控制在6.1~6.7避免了碳酸钙沉淀;Ca~(2+)、SO_4~(2-)分别不超过900mg/L和2 100mg/L,硫酸钙沉淀得到有效控制。酸液与矿石碳酸盐反应可获得400~450mg/L的HCO_3~-作为浸铀剂,在双氧水氧化条件下可使浸出铀浓度达到24~31mg/L,改用300~350mg/L的氧气则使铀浓度进一步升高到48~62mg/L。与常规酸法和碱法工艺相比,微酸中性工艺更有利于在浸铀的同时对硫酸钙和碳酸钙沉淀进行有效控制。     

氟碳铈镧精矿制取氯化稀土的研究

研究了氟碳铈镧精矿制取氯化稀土的工艺流程 ,试验确定了纯碱焙烧法分解氟碳铈镧精矿的工艺条件 ,该工艺能有效地除去碱土金属和钍等杂质 ,得到的稀土溶液REO>170g/L,Fe约5mg/L,ThO2相似文献   

Microstructure characteristics of spray-formed high vanadium and cobalt high speed steel

The microstructure of high vanadium and cobalt high speed steel(high-V/Co HSS) and the morphology of its carbides were analyzed by optical microscope(OM),scanning electron microscope(SEM),electron probe microanalysis(EPMA),X-ray power diffraction(XRD),atomic force microscopy(AFM) and single phase erosion(SPE).The results suggest that the as-sprayed high-V/Co HSS has fine equiaxed grains(about 20 μm in size),which were homogeneously distributed.The carbides have two classical morphologies:one is fine particles(about 2 μm in size) distributed along the grain boundaries and the other is needle-like one,distributed on the grain boundaries.There are MC carbides,M2C carbides,M6C carbides and Cr2WC2 carbides in the as-sprayed high-V/Co HSS samples,however,in the as-cast high-V/Co HSS,there are MC carbides and Cr2WC2 carbides only.The SPE results show that there are two types of MC carbides in the as-sprayed HSS:the sphere one and the particle-like one.The former is about 2 μm in size and the latter is less than 1 μm,dispersed inside the grains,quite different from the MC carbides in the as-cast HSS.According to the AFM results,the skeleton-like M6C carbides of the as-sprayed high-V/Co HSS are embedded in the matrix along the grain boundaries.It is found that there are sharp membrane pieces on the carbides.Some small bamboo-shoot-like MC carbides grow from the matrix and are dispersed inside the grain.Those larger MC carbides are spherical particles embedded at the grain boundary junctions.     

Reaction mechanism of cobalt cementation from high cobalt zinc sulphate solution by zinc dust

Abstract

The experiments in this paper were performed to research the mechanism of cobalt cementation from high cobalt zinc sulphate solution by zinc dust. The reduction potential of zinc during cementation was determined to investigate the morphology of products. Residues after the cementation process from zinc sulphate solution were analyzed by SEM and EPMA to investigate the morphology of products. Different temperature will cause different structure of particles. The reaction mechanism of cobalt removal by zinc dust is thought to be as follows: first, the Co2+ forms Co–Zn alloy with zinc particles, and the reaction reaches equilibrium quickly; second, the Co–Zn alloy continues reacting to Co with Co2+, which is the control process of the whole reaction.     

Magnetic properties of Pr-Dy-Fe-Co-B sintered materials with a high cobalt content

Materials (Pr_1?x Dy _x )_12–17(Fe_1?y Co _y )_balB_5–15 (x = 0.44–0.51 at %, y = 0.15–0.87 at %) have been studied. It is shown that the abrupt decrease in the coercive force of the (Pr_1?x Dy _x )_12–17(Fe_1?y Co _y )_balB_5-15 sintered materials with x = 0.44–0.51 and y > 0.25 is determined by the amount of boron-containing phases. In this case, an increase in the boron content in the (Pr_0.72Dy_0.28)_14.5(Fe_0.50Co_0.50)_balB _z material with an unchanged dysprosium content leads to an increase in the coercive force by 4.5 times. It is assumed that the escape of boron from the near-surface areas of R ₂ F ₁₄B-phase grains leads to the formation of regions characterized by a low anisotropy constant, which serve as nuclei for the formation of reverse-magnetization domains.     

Production of high purity cobalt oxalate from spent ammonia cracker catalyst

A process was developed to produce > 99.9% pure cobalt oxalate from spent ammonia cracker catalyst pellets containing ∼ 20% Co generated at heavy water plants. A pilot plant for producing kilograms of cobalt oxalate of required purity has been set up. The process consists of leaching, oxidation, solvent extraction, ion exchange and oxalate precipitation. The major impurities present in the leach liquor after nitric acid oxidation were Fe³⁺, Al³⁺ and Ni²⁺. Fe³⁺ and Al³⁺ were separated from the leach liquor by using a solvent extraction (SX) process employing a mixed extractant system consisting of D2EHPA and TBP. Ni²⁺ was separated by ion exchange (IX) employing Dowex M4195 resin.     

火焰原子吸收光谱法测定催化剂中高含量钴和镍

提出了用火焰原子吸收光谱法测定加氢精制催化剂中高含量钴和镍的方法。在聚四氟乙烯高压釜内,用王水溶解样品。钴、镍的最灵敏吸收线波长分别为240 .7nm,232.0nm。空气-乙炔火焰测定高含量钴、镍时,用波长分别为352 7nm,341 5nm的次灵敏线,可提高测定的精密度、又能使工作曲线的线性范围变宽。钴量在0～70μg/mL、镍量在0～150μg/mL范围内呈良好线性关系。对催化剂样品进行分析时,相对标准偏差为1.15%～3.85%。对样品进行加标回收实验,回收率在98.1%～101.5%。方法的精密     

Fatigue crack initiation and propagation behavior of high cobalt molybdenum stainless bearing steel

The crack initiation and propagation behavior of high cobalt molybdenum stainless bearing steel was studied by rotating bending fatigue test with smooth cylindrical specimens and notched specimens (theoretical stress concentration factor Kt=3). The fatigue limit and S- N curve of bearing steel were measured by up- and- down method and group method, respectively. The fractures of the specimens were observed by scanning electron microscopy. The results show that the cracking type of the smooth specimens is single source initiation. The crack source is surface defects and subsurface inclusion. The surface defects are surface roughness, persistent slip band and machining dent, while the subsurface inclusion is Al2O3- CaO- MgO- SiO2 composite inclusion. The fatigue limit of notched specimens is significantly decreased. The cracking type of the notched specimens is multi- source initiation. The notch sensitivity factor qf of bearing steel is 1. 18. The fatigue failure of the smooth specimens is transferred from the surface roughness with high stress amplitude to the persistent slip bands, the machining dents and the inclusions with low stress amplitude. The fatigue crack initiation life accounts for more than 94. 1% of the whole fatigue life.     

Mechanisms in the simultaneous erosion-oxidation attack of nickel and cobalt at high temperature

An apparatus is described by which a specimen may be exposed to a well-defined erosive gas stream containing 20 μm alumina particles. Samples of nickel and cobalt were exposed to conditions of erosion and high temperature oxidation simultaneously, using 90 deg impact angle, at velocities up to 140 m/s^-1 and at temperatures up to 800 °C. From the results of erosion kinetics, surface morphologies, and cross section metallographic observations it is concluded that several definite regimes of interaction between erosion and oxidation exist. These regimes are described in qualitative terms, and it is shown how they arise as a result of the balance between the relative intensities of the erosion and oxidation processes.