固体电解质脱氧技术的发展

目前一种采用氧化锆固体电解质脱氧的技术受到了广泛关注。文章对熔融金属液固体电解质脱氧新理论及研究现状进行了阐述,比较了电解脱和短路脱氧方法的优劣。对氧化锆固体对解质材料的晶体结构、相变、离子导电机理及力学性能进行了概述,并探讨了固体电解质脱氧技术的发展趋势。     

以氧传感器为基的辅助电极型冶金传感器的研究进展

金属熔体的化学组成是金属冶炼过程的重要参数,固体电解质传感器可以提供金属冶炼过程中成分变化的实时信息;这些信息可以提高生产效率,提升产品质量.由于缺乏以待测元素为导电离子的固体电解质,除氧以外的一些元素的测量多通过在电解质的表面涂覆一层含待测元素和电解质中导电离子元素复合物的方法来实现.总结了氧传感器及其他元素成分传感器的研究进展,介绍了以氧传感器为基础的辅助电极型成分传感器,并对辅助电极型传感器的应用和发展进行了展望.     

钢液中原子与夹杂物颗粒间的介尺度物相及二步形核

大量试验和工业生产实践表明,钢液用金属(如铝、硅)脱氧反应难以达到生成固体氧化物夹杂的热力学平衡状态,即脱氧产物不能完全转变为最稳定结构的晶体或固体氧化物夹杂,部分脱氧产物以稳定性低于氧化物夹杂的亚稳相形式存在。亚稳相是熔体中处于原子与夹杂物颗粒尺度之间的介尺度物相,同时其结构也是介于液态(包括无定型)与稳定的固态(包括晶体)结构之间的演变状态。利用第一性原理方法优化显示,金属脱氧体系中的介尺度亚稳相包括形核前的不同数目的脱氧剂原子和氧原子结合的氧化物团簇、团簇聚集体、临界核以及形核后的纳米尺寸氧化物夹杂。热力学平衡计算发现亚稳相恰好与脱氧后体系中的脱氧剂和氧元素含量达到平衡。脱氧过程中夹杂物形核服从二步机理,第一步为脱氧剂原子与氧反应生成团簇,该过程的热力学趋势大、反应速率快,反应平衡决定了脱氧后的溶解氧含量;第二步为团簇聚集成核,该过程涉及团簇的扩散和类液态结构向固态或晶体结构的转变行为,是脱氧反应的限制性环节,决定了夹杂物的形核率。因此,要实现对夹杂物尺寸分布的控制,需进一步研究影响第二步的相关因素以及控制方法。     

添加石墨粉对直接电脱氧法制备金属锆的影响

通过在固体ZrO2阴极片中添加不同量的石墨粉,采用直接电脱氧法制备金属锆,研究了经烧结并直接电脱氧后阴极的成分及形貌,考察了添加石墨粉对电脱氧反应的影响。研究结果表明,加入石墨粉可提高烧结样品中的氧空位,增加反应活性,提高金属锆的收率,降低能量消耗。     

钢液固体电解质定氧电池的改进和应用

文章总结了作者1975年以来研制和使用钢液固体电解质浓差定氧电池的经验。通过对比试验,指出了提高其测成率和信号稳定性的一些关键。对测定结果的可靠性亦用多种方法进行过鉴定。用浓差定氧对电炉冶炼工艺进行研究得知:出钢终脱氧前熔池中的氧活度与钢材的氧化物夹杂评级密切有关,降低终脱氧前的钢中氧活度对提高钢材的洁净度有利。当采用铝预脱氧工艺时,电炉还原期可以大大缩短。用浓差电池定氧还研究了氧气底吹转炉冶炼过程中熔池含氧量的变化规律。判明了在吹炼终点使用锰铁预脱氧无明显效果。而鼓入氮气可以使钢中含氧量降低约50％。浓差定氧还可用于判断和控制钢锭上涨及皮下气泡的发生。     

金属液电化学无污染脱氧方法

本发明属于冶金技术。本发明以炉渣作为金属液内溶解氧向外传输的通道，在金属液与覆盖于其上的熔渣之间施加直流脉冲电场，控制氧离子在熔渣体系中的传导方向和速度，从而实现金属液的无污染脱氧。该发明具有设备操作简单，脱氧速度及强度易控制且成本低廉等一系列优点。     

透氧膜法直接制备LaNi_4Al合金的研究

采用固体透氧膜(SOM)法电解La_2O_3-NiO-Al_2O_3烧结片,直接制备储氢合金LaNi4Al。该工艺用只允许氧离子通过的固体透氧膜隔开阴极和阳极,可采用较高的电解电压(3.8V)以获取更高的电解速率。采用SEM和XRD分析了烧结阴极片形貌、组成以及在熔盐中浸蚀后的变化,通过电解中间产物相组成分析了反应机理。结果表明:SOM法由La_2O_3-NiO-Al_2O_3直接制备LaNi4Al是可行的;La_2O_3-NiO-Al_2O_3阴极片1150℃烧结后的组成为LaAlO_3、NiO;烧结片电解机理为LaAlO_3脱氧生成LaOCl、Al,NiO脱氧反应生成Ni,随后LaOCl、Al、Ni反应生成LaNi4Al;反应的电流效率为92.7%,能耗3.55kW·h/kg。工艺流程短、效率高,有良好的应用前景。     

LiCl-NaCl熔盐中金属钽电化学脱氧过程研究

通过循环伏安法、恒槽压电解并结合SEM、XRD和氧氮分析法研究了LiCl-NaCl熔盐中金属钽的电化学脱氧过程,并考察了石墨阳极气体对脱氧过程的影响.研究结果表明:在LiCl-NaCl熔盐体系中,利用电解可有效降低金属钽中的氧含量,脱氧反应包括Ta2O5→Ta(O)+LiTaO3和Ta(O)+LiTaO3-Ta.熔盐电...     

Fe-Nb-O系平衡及其热力学参数的研究

用ZrO_2(MgO)固体电解质氧浓差电池测定了1833、1873、1913KFe-Nb-O熔体(0.004～3.8％Nb)平衡时的氧活度,用X射线衍射物相分析方法对铁液中铌的脱氧产物进行了检验,计算出了1833～1913K温度范围内的Nb-O平衡常数和其它有关热力学参数。实验结果表明:当铁液中铌含量约高于0.2％时,铌的脱氧产物是具有金红石结构的正方型NbO_2;在0.05～0.2％的铌含量范围内,脱氧产物是Nb_2O_5;当铁液中铌含量低于0.05％时,脱氧产物是FeNb_2O_6。随着铁液中铌含量的降低(即氧活度增大),铌的脱氧产物形态发生转变,其顺序是:NbO_2→Nb_2O_5→FeNb_2O_6     

Ca-CaCl2熔盐法制备低氧金属钇的研究

主要开展了用Ca-CaCl2熔盐法制备低氧金属钇(Y)的研究.采用Ca-CaCl2熔盐法,在高温电阻炉内,利用溶解于CaCl2中的化学活性钙与氧的反应,除去钇中的氧,而熔融的CaCl2可降低副产品CaO的活度,从而得到低氧金属钇.通过对不同助熔剂用量、不同材质坩埚、不同脱氧时间、不同脱氧温度进行的研究,我们找到了在钇试样为5g时,用Ca-CaCl2熔盐法脱氧的最佳助熔剂用量为40g,较佳脱氧时间为7天,较佳脱氧温度为950℃,使用钽坩埚可以使块状的钇脱氧后的最低氧含量达到0.17%(质量分数,下同),使氧的去除率达到了73%.     

China's Major Non-ferrous Metals Imports & Exports

正~~     

Zinc Production by Province in 2014

正~~     

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.