用失效的C－Pd催化剂生产氯化钯

介绍了用锌镁粉直接还原与处理失效废弃的Ｃ－Ｐｄ催化剂，并用自制混酸直接生产氯化钯的工艺。该工艺比传统的铝粉置换法更快捷，钯收率更高。     

从失效的C—Pd催化剂中回收钯

采用氧化焙烧、盐酸浸出处理失效C—Pd催化剂,并从浸出液中用氨络合或离子交换精炼钯的工艺,钯的直收率>98％。     

从Pd/C废料中回收钯及制备试剂PdCl2的新工艺

以国内某制药企业使用过的废钯炭催化剂为原料,研究了用王水溶解-氯化铵直接沉淀法回收钯的新工艺,取代了传统的王水溶解-氨水配合法.新工艺实现了钯和贱金属的有效分离,贵贱金属分离效果好,大幅度缩短了生产周期,降低了生产成本,提高了生产效率.经过10批次的实际生产验证,钯的平均直收率为99.20％,平均总收率为99.94％.采用氯气微压催化溶解钯的新工艺制备二氯化钯,保证了产品中无硝基,质量稳定、操作简单、环境更友好.     

从环氧乙烷用失效催化剂中回收银

采用流态化浸出技术研究了从环氧乙烷用失效银催化剂中银的工艺。考察了流化状态、硝酸用量、反应时间等参数对银浸出效果的影响,得到了最佳工艺条件。采用自制流化态溶解装置,使废催化剂处于流动翻滚状态,硝酸用量为理论用量的1.2倍,反应时间不低于1 h,银的浸出率可达到99.88%。浸出液氯化沉淀后采用传统方法精炼提纯,得到99.95%纯度的银。     

从失效催化剂中回收铂的工艺

本文对Ｒ－３２和１－５的二种催化剂（含Ｐｔ≈０．３％）回收铂的工艺进行了实验室研究。采用高温焙烧－盐酸＋氧化剂浸出－溶剂萃取铂新工艺。一次浸出作业可使废渣含Ｐｔ降至５０ｇ／ｔ以下，用Ｎ２３５萃取代替现行的锌粉置换，铂回收率可提高１％以上；用水解法精制后，可获得９９．９８％铂产品，实收率９７％以上。     

从失效Pt-V/C催化剂中回收铂的新工艺

由于化学性质相似,铂钒分离提纯比较困难。对失效Pt-V/C催化剂中铂的回收进行了研究,重点考察了盐酸浓度、温度和氯化铵的用量3种工艺参数对铂钒分离的影响,得出优化的工艺条件:在室温下,盐酸浓度为3.0 mol/L,氯化铵与铂的质量比为4~5,可以实现铂的有效沉淀分离。经精炼可以获得纯度为99.95%的海绵铂,铂的回收率大于99.5%。     

从失效载体催化剂回收铂的工艺研究

用硫酸溶解γ-Al2O3-焚烧脱炭-“消化”转溶α-Al2O3-铂精矿精炼铂的火湿法冶金工艺处理复杂成份失效载体催化剂效果好,铂产品纯度＞99.5%,回收率＞97.5%.     

从失效丙烷脱氢催化剂中回收铂

失效丙烷脱氢催化剂以α-Al2O3为载体,由于载体α-Al2O3酸碱不溶的性质,采用盐酸-氯酸钠浸出回收其中的铂。由于失效催化剂积碳较高,为38.84%,先焙烧除碳预处理,再研究温度、液固比、时间等浸出条件对铂浸出率的影响。结果表明,失效催化剂中铂的适宜浸出条件为浸出温度80 ℃,液固比8:1 (mL/g),反应时间60 min,HCl浓度6 mol/L,饱和氯酸钠溶液与原料质量比1:6 (mL/g),此时铂浸出率98.64%,铂得到有效回收。     

用乙酰丙酮钯作前驱物制备Pd/C催化剂的研究

分别采用乙酰丙酮钯、氯化钯和硝酸钯作前驱物,用浸渍-还原法制备了一系列Pd/C催化剂,以松香歧化反应评价其活性,研究了活性炭类型、载体预处理、溶剂、还原方法及温度等因素对Pd/C催化剂活性的影响.结果表明,采用具有较大比表面积和孔容的活性炭作载体有利于钯在其表面的均匀分布和催化剂活性的提高;以Pd(acac)2作前驱体,以及使用极性较强的溶剂与用无机配合物前驱体相比,制备的Pd/C催化剂活性较高;TG-DTA分析表明Pd(acac)2在350℃下完全分解,基于此结果,作者在350℃条件下采用氢气干法还原,制备出活性略高于从日本进口的Pd/C催化剂.     

生产氢气用的廉价催化剂

美国特拉华州立大学由化工系教授Chen J G等所组成的研究小组，新近研制成功一种可取代水电解制氢过程中所用白金催化剂的新型催化剂——表面镀铂的碳化钨基催化剂，它是以WC为基体在其表面涂镀了一层单原子铂。     

从废炭-钯催化剂中提取钯

本文根据大庆石化总厂乙醛装置排出的废C -Pd催化剂的组成 ,阐述了经焚烧、王水溶解、氨水络合、酸化、烘干、煅烧等从废催化剂提取金属钯的工艺流程及生产方法。该回收工艺简单 ,成本低 ,Pd的总回收率 >90 % ,纯度 >99%     

废催化剂中钯的回收

用硫酸溶解载体－盐酸＋氧化剂浸出－离子交换提取３１－１Ａ催化剂（含Ｐｂ０．０３１％）中的钯，可获得纯度９９．９７％Ｐｄ产品，实收率〉９７％。     

从生产乙醛废催化剂渣中回收钯和铜

以盐酸为浸出剂,H_2O_2为氧化剂,采用二段逆流浸出法先将Pd和Cu从废催化剂泥渣中浸出,然后采用乙基黄原酸钠为沉淀剂,进行钯的富集,达到钯和铜的分离。还比较了不同的盐酸浓度对钯的浸出效果以及不同pH值及乙基黄药的加入量对钯沉淀的影响。     

从含Pt废催化剂回收Pt,Al的新工艺

用消化－水浸分离含Ｐｔ废催化剂（Ｉ５）中Ｐｔ和Ａｌ。铂富集物经氯化溶解，精制纯铂；铝溶液制含铝产品。     

氯化钯制备过程中赶硝工艺的研究

研究了以Pd(NH3)2Cl2作原料,用水合肼还原成金属钯,王水溶解钯制备PdCl2的工艺,着重研究了采用MxOy+HCl复合赶硝剂对降低PdCl2产品中NO3-含量和赶硝过程中NO2生成的影响。结果表明,加入MxOy可大大降低PdCl2中NO3-的含量,当每公斤海绵钯加入7L(1∶1)王水,在30℃左右溶解后加入1L浓HCl和1.5LMxOy(35%)时,一次性赶硝,PdCl2中NO3-的含量<0.03%。复合赶硝剂的应用可解决采用HCl作赶硝剂,反复赶硝,不仅产生大量NO2污染环境,而且导致PdCl2产品中NO3-含量高的问题。     

A Technology for Recovering Silver and Palladium from MLCC Scraps

ＡＴｅｃｈｎｏｌｏｇｙｆｏｒＲｅｃｏｖｅｒｉｎｇＳｉｌｖｅｒａｎｄＰａｌａｄｉｕｍｆｒｏｍＭＬＣＣＳｃｒａｐｓＨｅＸｉａｏｔａｎｇａｎｄＺｈａｏＹｕｎｋｕｎ（贺小塘）（赵云昆）ＩｎｓｔｉｔｕｔｅｏｆＰｒｅｃｉｏｕｓＭｅｔａｌｓ,Ｋｕｎｍｉｎｇ６５０２...     

A New Energy-Efficient and Environmentally Friendly Process to Produce Aluminum

The Hall–Heroult process to produce aluminum is more than 125 years old. Larger, more efficient cells have been developed, and process control has improved, but the process is basically unchanged. A new process has been under development since 1990 that promises 20% lower capital cost and 20% lower operating cost and no CO₂ or fluorocarbon emissions. A new cell design, new anode and cathode materials, new electrolyte, and new operating conditions are based on experience over the past six decades. The evolution of this technology to its present state is described here.     

Plasma Spray-CVD: A New Thermal Spray Process to Produce Thin Films from Liquid or Gaseous Precursors

New dedicated coating processes which are based on the well-known LPPS™ technology but operating at lower work pressure (100 Pa) are being actively developed. These hybrid technologies contribute to improve the efficiencies in the turbine industry such as aero-engines and land-based gas turbines. They also have a great potential in the domain of new energy concepts in applications like Solid Oxide Fuel Cells, membranes, and photovoltaic with the adoption of new ways of producing coatings by thermal spray. Such processes include Plasma Spray-Thin Film (PS-TF) which gives the possibility to coat thin and dense layers from splats through a classical thermal spray approach but at high velocities (400-800 m/s) and enthalpy (8000-15000 kJ/kg). Plasma Spray-PVD (PS-PVD) which allows producing thick columnar-structured Thermal Barrier Coatings (100-300 μm) from the vapor phase with the employment of the high enthalpy gun and specific powder feedstock material. On the other hand, the Plasma Spray-CVD (PS-CVD) process uses modified conventional thermal spray components operated below 100 Pa which allows producing CVD-like coatings (<1-10 μm) at higher deposition rates using liquid or gaseous precursors as feedstock material. The advantages of such thermal spray-enhanced CVD processes are the high ionization degree and high throughput for the deposition of thin layers. In this article, we present an overview of the possibilities and limitations encountered while producing thin film coatings using liquid and gaseous precursors with this new type of low pressure plasma spray equipment and point out the challenges faced to obtain efficient injection and mixing of the precursors in the plasma jet. In particular, SiO _x thin films from Hexamethyldisiloxane (HMDSO or C₆H₁₈OSi₂) can be deposited on wafers at deposition rates of up to 35 nm/s at an efficiency of about 50%. The process was also used for producing metal oxide coatings (Al₂O₃, ZnO, and SnO₂) by evaporating different metals in combination with an oxygen gas flow. The effect of process parameters on the deposition rate, coating build up, uniformity, and quality of the coatings are discussed. An overview of different potential applications of this new technology will be also presented.     

减径机生产中空六角钢的工艺方法

介绍了生产中空六角钢的工艺方法,提出了一种新方法——穿轧减径成型法,并采用模拟软件重点模拟了减径成型过程的成型阶段.结果表明：利用减径机直接生产中空六角钢的工艺是可行的,即穿轧减径成型工艺可行.采用穿孔减径成型法生产中空六角钢时,减径机成型机架须采用合适的孔型尺寸,成型机架单机架延伸系数及孔型尺寸须满足金属合理流动的要求;成型机架单机架延伸系数取1.15～1.25较合适.