EDTA返滴定法测定高含量氯化亚汞

在pH9.5-10氨缓冲溶液中，以甲基黄、铬黑T为指示剂，样品溶液中加入过量的EDTA与Hg^2 等离子生成络合物，多余的EDTA用镁标准溶液反应完全后，再加入碘化钾，碘离子与汞离子形成更稳定的络合物，由此释放出等量的EDTA，然后用镁标准溶液滴定释放出的EDTA，求得氯化亚汞的含量，该法适应于Hg2Cl2含量在98％以上样品的测定，方法的相对标准偏差为0.087％-0.12％。     

沉淀分离-连续滴定法测定电解液中氟硅酸和铅

在电解液中加入硫酸钾,使氟硅酸和铅生成沉淀与其它元素分离,再将沉淀转化为可滴定的溶液,用氢氧化钠标准滴定溶液滴定氟硅酸后,再用EDTA标准滴定溶液滴定铅.沉淀分离-连续滴定的方法准确、快速,满足生产分析要求.     

多元校正电位络合滴定法同时测定合金中铜铅锌

建立了一种可同时测定合金中铜、铅、锌等多组分含量的电位络合滴定方法。用ED-TA与氟化钠的混合溶液作为滴定剂,被滴定液中同时插入了汞膜电极和氟离子选择电极,在滴定过程中的任一滴定点,溶液中汞离子的浓度和滴定剂的加入体积可由两个电极的电位测定值同时获得,从而可应用多元校正法由相应的滴定曲线求得混合金属中每一种组分的含量。该方法免去了直接读取滴定剂的体积,且不需确定滴定终点。应用本方法同时对合金样品中的铜、铅、锌进行了测定,其相对标准偏差为0.18%~0.45%,回收率为99.5%~101.6%。     

高含量铜、钴、钼精矿试样中铁的分析测定

试样经硝酸-氯酸钾饱和溶液分解，于盐酸溶液中，用氢氧化铵-氯化铵沉淀分离。在强盐酸溶液中用二氯化锡溶液还原铁的三价离子，过量的二氯化锡用碘酸钾、硫酸银氧化还原，以二苯胺磺酸钠为指示剂，用重铬酸钾标准溶液滴定。     

EDTA差减滴定法测定汞污染土壤中汞

提出了快速测定汞污染土壤中汞含量的EDTA差减滴定法。土壤样品用H3PO4和H2SO4混合酸溶解,用焦磷酸钠掩蔽Cu2+,调至pH5～6,以二甲酚橙为指示剂,用EDTA标准溶液滴定溶液中能与EDTA络合的全部金属离子的总量;然后在另一份相同试液中,先加入硫脲掩蔽Hg2+,再用EDTA标准溶液滴定除汞外的其它金属离子,利用二者之差计算汞的含量。改进后的方法,简单、快捷、干扰小,测定结果与国家标准方法一致,相对标准偏差小于2.0%,加标回收率在97.2%～100.1%之间。     

硫酸亚铁铵滴定法连续测定铝钒锡铬合金中钒和铬

铝钒锡铬合金是冶炼钛合金的一种中间合金,为了准确、快速测定该合金中钒和铬,对硫酸亚铁铵滴定法连续测定该合金中高含量钒和高含量铬的条件进行研究并建立了测定方法。试样以硫酸-磷酸-硝酸的混酸分解后,在常温下,以高锰酸钾氧化钒,亚硝酸钠还原过量的高锰酸钾,同时用尿素分解多余的亚硝酸钠,用硫酸亚铁铵标准滴定液滴定钒,根据消耗的硫酸亚铁铵标准滴定液体积,求得钒含量;在加热情况下,将滴定钒后的溶液在硝酸银的催化作用下,用过硫酸铵溶液将钒和铬同时氧化至高价,再用硫酸亚铁铵标准滴定液滴定钒和铬的合量,两次滴定所消耗滴定液的体积之差即为滴定铬所需滴定液的体积,据此求得铬的含量。方法用于铝钒锡铬合金样品中钒和铬的测定,测定结果的相对标准偏差(RSD,n=10)分别为0.22%和0.75%,加标回收率分别在101%～105％和96％～101％之间。     

炉甘石中ZnCO_3,ZnO,PbCO_3,Fe_2O_3,(CaCO_3+MgCO_3)含量测定的研究

（１）以氨水（１＋４）溶解样品，用ＸＯ作指示剂，ＥＤＴＡ滴定，测定ＺｎＣＯ３含量。（２）以１５％的硫酸铵溶解样品，用ＸＯ作指示剂，ＥＤＴＡ滴定，测定（ＺｎＣＯ３＋ＺｎＯ）含量。（３）以１５％的氯化铵溶液溶解样品，用ＥＢＴ作指示剂，ＥＤＴＡ滴定，测定（ＺｎＣＯ３＋ＺｎＯ＋ＣａＣＯ３＋ＭｇＣＯ３）含量。（４）以１６％的乙酸铵溶液溶解样品，以ＸＯ作指示剂，ＥＤＴＡ滴定，测定（ＰｂＣＯ３＋ＺｎＣＯ３＋ＺｎＯ）含量。（５）以稀盐酸溶解样品，用磺基水杨酸作指示剂，ＥＤＴＡ滴定，测定Ｆｅ２Ｏ３含量。     

利用金电极极谱测定矿石中的铁

矿石中高含量铁一般均采用容量法进行测定,虽然近年来铁的容量法进行了改进,均采用无汞测铁的方法,改去汞对环境的污染,但滴定的标准溶液还是用重铬酸钾溶液,而铬也将对环境带来一定的污染。为此考虑到铁在氢氧化钠—三乙醇胺,或盐酸溶液中均能得到很好还原波的性能,利用金电极在硫磷混酸—盐酸溶液中对三价铁     

还原钛铁矿中全铁的无污染法测定

关于矿石中全铁的测定,经典方法系采用二氯化锡还原,加入饱和氯化汞后,以重铬酸钾标准溶液滴定,求得全铁量。日常分析则多用SnCl_2—TiCl_3还原,加钨酸钠或靛蓝等作指示剂,用重铬酸钾溶液氧化过量TiCl_3,或加入催化剂使剩余TiCl_3在空气中自然氧化后,再用重铬酸钾溶液进行滴定。后者可消除汞对环境的污染,但需消除过剩TiCl_3,给操作带来了麻烦。     

溴酸钾滴定法测定矿物中的砷

试样硫酸分解，硫化钠为还原剂，并于硫酸介质中，在60—80℃之间，以亚甲基兰为指示剂，用溴酸钾标准滴定溶液滴定砷（Ⅲ）至紫红色为终点。本法适于矿物中大于0．1％砷的测定。     

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.