超细γ-Al_2O_3粉体化学沉淀法的合成及表征

分别以碳酸氢铵和氨水作为沉淀剂,采用化学沉淀法制备超细Al2O3粉体。研究沉淀剂对制备氧化铝前驱体的影响,分散剂对颗粒尺寸和形貌的影响及煅烧温度对产物晶型和颗粒尺寸的影响。利用SEM、XRD、DSC对γ-Al2O3粉体的性能进行了表征。结果表明:以碳酸氢铵为沉淀剂制备出的Al2O3粉体的平均粒径最小;该方法制备出的氧化铝前驱体在900℃下煅烧保温2h可制备出粒径细小,粒径为70nm左右的Al2O3粉体。     

水热法制备纳米氧化镁

以氯化镁与氨水为原料,聚乙二醇为分散剂,用水热法制备出纳米氧化镁。通过X射线衍射仪和扫描电子显微镜表征产物的晶体结构、显微形貌和颗粒尺寸,探讨了MgCl₂和氨水的摩尔比、反应温度、反应时间对前驱体的影响。对前驱体进行差热分析,研究前驱体煅烧温度和煅烧时间对纳米MgO的影响。结果表明：当MgCl₂和氨水的摩尔比为1.0:2.5,反应温度为200℃,反应时间为3.0 h,前驱体煅烧温度为600℃,煅烧时间为2.0 h时,得到的纳米MgO颗粒呈圆盘状,分散均匀,基本无团聚现象,颗粒直径约为100 nm,厚度最小约为10 nm。     

水热水解法制备钇稳定纳米氧化锆工艺研究

以氧氯化锆、氯化钇和氨水为原料,聚乙二醇为分散剂,采用水热水解法制备钇稳定氧化锆(YSZ),系统研究了锆离子浓度、反应温度、钇掺杂量、分散剂添加量以及煅烧温度对氧化锆产品形貌、分散性、粒度和晶型的影响。结果表明：在锆离子浓度0.8 mol/L、反应温度180℃、钇掺杂量3%(摩尔分数)、分散剂添加量2%(质量分数)和煅烧温度1 000℃的条件下,可制得分散性好、粒度分布均匀的类球状钇稳定纳米氧化锆粉末。     

亚微米氧化镧的制备技术研究

本文以硝酸镧为原料,采用燃烧法、溶胶-凝胶法、水热法制备氧化镧粉体,研究不同制备方法对粉体粒度和形貌的影响,同时系统地研究了水热法中反应温度、反应时间和料液浓度对粉体粒度的影响。实验结果表明,水热法制备的氧化镧在粉体颗粒的均匀性和分布上更有优势,通过对水热法各参数的研究,在反应温度140℃、反应时间8h、料液浓度0.75mol/L时,可稳定地制备出D50<0.3μm,分布<0.8的亚微米氧化镧粉体。     

沉淀法制备ITO粉体及其性能研究

以InCl3、SnCl4、尿素和氨水为主要原料,采用化学共沉淀法制备出ITO粉体,探讨了沉淀剂种类和煅烧温度对ITO粉体性能的影响。结果表明：采用氨水可制备针状、粒度分布窄的纳米粉体,沉淀剂为尿素时则为块状、粒度分布较宽的微米粉体;随煅烧温度的提高,粉体的比表面积呈下降趋势,从700℃的28．65m2／g下降到900℃的12．23m2／g;氨水作沉淀剂且煅烧温度为700℃时可获得粒度均匀、分散性好、物相单一的纳米ITO粉。     

化学还原法原位制备石墨烯/纳米银复合粉体及其导电性能

以水合肼为还原剂,PVP为分散剂,在反应温度为60℃,p H为6条件下同时还原氧化石墨烯和硝酸银,原位制备石墨烯/纳米银复合粉体。通过扫描电镜、X射线衍射、红外吸收光谱和拉曼光谱等手段研究溶液中硝酸银的质量浓度对石墨烯/纳米银复合粉体形貌与结构的影响。用石墨烯/纳米银复合粉体替代部分微米银粉制备低温固化导电浆料,对其导电性能进行研究。结果表明:银纳米粒子分布于石墨烯片层之间。当反应溶液中硝酸银的质量浓度为0.75 g/L,氧化石墨烯质量浓度为0.25 g/L时,获得分散性好,粒径均匀的石墨烯/纳米银复合粉体,且负载在石墨烯片层上的银纳米粒子的粒径集中在100 nm左右。用石墨烯/纳米银复合粉体替代4%微米银粉制备导电浆料,浆料的体积电阻率为1.8×10-5Ω·cm,与未添加石墨烯/纳米银复合粉体的导电浆料相比,电阻率降低61.7%。     

均匀沉淀法合成纳米Y2O3研究

以硝酸钇为原料,尿素为沉淀剂,低分子量聚丙烯酸钠为分散剂,研究了采用均匀沉淀法合成纳米Y2O3的工艺过程.制备条件为钇离子浓度0.3mol/L; 尿素与硝酸钇的摩尔比为41;分散剂聚丙烯酸钠的用量为1%(体积分数);反应时间4h,反应温度95℃;煅烧温度为850℃,煅烧时间3 h.制备得到粒径为32nm、无团聚、粒径均匀的纳米Y2O3.     

电池级Co3O4的制备

研究了用碳铵直接沉淀氯化钴制备前躯体进而煅烧制备电池级Co3O4的工艺.主要考察了氯化钴溶液中钴离子浓度、溶液起始pH值、沉淀反应温度、沉淀反应时间等对前躯体粒度分布的影响,以及前躯体煅烧温度、煅烧时间对产物Co3O4颗粒形貌、粒度的影响.XRD研究表明,用该方法制备的前驱体粉末为无定形的碱式碳酸钴,经过煅烧后生成均匀分散的Co3O4粉末.XRD、SEM、粒度分布、振实密度等测试对煅烧产物进行了性能表证,结果显示产物具有标准Co3O4晶型结构,结晶良好,粉末具有规整的颗粒形貌,并且具有较好的分散性,平均粒径l～5 μm,振实密度2.1 g·cm-3,满足电池级Co3O4的要求.     

中和结晶过程对Ta2O5粉末粒度特性的影响

采用中和结晶-煅烧法制备Ta2O5粉末,分别考察了中和结晶过程中钽液浓度、钽液起始pH值、结晶温度、氨水浓度、氨水流速和搅拌速度等六个因素对Ta2o5粉末粒度的影响.试验结果表明,在钽液浓度c(Ta2O5)为95g/L,钽液起始pH=1.80,水浴温度60℃,氨水浓度8.0 mol/L,氨水流速1.0 mL/min,搅拌速度40 r/min的条件下,制得的Ta2o5粉末最大平均粒径可达180μm,完全满足生产需求.     

喷雾热分解法合成BaTiO_3超细粉末及其形貌控制

以钛酸四异丙酯(TTIP)及醋酸钡为前驱体,采用超声喷雾热分解法制备了钛酸钡超细粉体。在分析了BaTiO3粉体喷雾合成机理的基础上,考察了反应温度、前驱体溶液浓度、溶液流量和载气流量等工艺参数对粉体粒度和形貌的影响。结果表明:反应温度、前驱体溶液浓度、溶液流量及载气流量与产物颗粒的粒度及分布、球形度、纯度以及结晶度等密切相关;当反应温度为900℃、前驱体溶液浓度为0.1mol/L、溶液流量为2ml/min、载气流量为2 L/min时,得到的BaTiO3粉体平均粒径为2.4μm,粒度分布较均匀、结晶度高、球形度好、空心破壳少。     

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.     

Seven Rare Earth Projects Involving Close to 3 Billion Yuan Investment Landed In the HighTech Zone

正On May 22,Baotou Rare Earth Industry Cooperation Consultation MeetingProject Agreement-signing Ceremony was held in Ningbo,nearly 40 enterprises from Ningbo,Guangdong,Hunan,and Shanxi participated in project consultation.After multi-lateral communication,agreements were signed for a total of 7 rare earth projects successfully.