氟盐取代络合滴定法测定铝锰合金中铝含量

采用一种无需预先分离铁、锰,直接用氟盐取代络合滴定法测定铝锰合金中铝含量。试样经盐酸和H2O2溶解后,在一定量的铜离子存在下,加入过量的EDTA溶液,使其与溶液中铁、锰、铜等金属离子络合,煮沸溶液使铝也全部形成络合物,以PAN为指示剂,用铅的标准溶液回滴过量EDTA,加入氟化物使Al EDTA络合物解蔽,释放出与铝等量EDTA,再用铅的标准溶液滴定,由此计算铝的质量分数。试验并确定了测定过程中的最佳分析条件。方法用于分析铝锰合金中铝含量,其相对标准偏差小于0.2%,结果与经典的碱分离EDTA滴定法相符。该方法可用于测定铝锰合金中铝质量分数为15%～30%的样品。     

氟化物取代EDTA滴定法快速测定铝锰镁合金中铝

试样以酸溶解后,采用定量的氯化钡与过量的氢氧化钠一次性沉淀分离铝锰镁合金中的锰、铁、镁干扰元素,再用氢氧化钠沉淀分离铁、镁的二次沉淀与铝分离。滤液中加过量于铝的EDTA标准溶液,调节pH。左右使铝与其它少量干扰元素配位络合物,以PAN为指示剂,用硫酸铜标准溶液滴定过量的EDTA。加氟化铵煮沸取代出与铝定量络合的EDTA,再用硫酸铜标准溶液滴定被’氟化铵配位取代的EDTA,借此测定合金中的铝量。     

硅铝坝合金中铝量的快速测定

阐述了硅铝钡合金中铝量的快速测定方法。试样经酸溶解后，在一定条件下使铝与酒石酸的络合物被氟化钠破坏，定量地游离出碱，然后以酚酞作指示剂用硝酸标液滴定碱，进而计算出铝量。     

EDTA容量法测定铝锰合金中铝

采用氯化钠和氢氧化钠联合一次性沉淀锰、铁、钛等干扰元素,铝离子与EDTA络合后,用硫酸铜滴定氟盐取代释放的与铝络合的EDTA,测定铝锰合金中之铝.     

锰铝碳合金中铝的EDTA快速络合滴定

EDTA络合滴定铝时,大量锰存在严重干扰,需分离后测定。为了减少高锰材料中测定铝的复杂性,R.Pribit等采用TTHA为滴定剂,甘氨酸邻甲酚红为指示剂不分离测铝;刘传文研究了Cu—EDTA—PAN为指示剂,邻菲啰啉为催化剂直接测铝的方法。本文采用Cu—PAN—Phen三元络合物为指示剂,pH6.5～7.2,过量EDTA络合铝锰、氟化物释放与铝结合的EDTA,铜锌混合标准溶液返滴     

铬天青S分光光度法测定锰铁合金、锰硅合金、金属锰中铝

铝在锰铁合金、锰硅合金、金属锰中属于有害元素,在后续钢铁冶炼中易形成夹杂物而使钢铁材料变脆,为此建立了铬天青S分光光度法测定锰铁合金、锰硅合金和金属锰中铝的方法。以硝酸、氢氟酸分解样品,利用高氯酸冒烟提供高温和强氧化作用,硅与氢氟酸反应生成四氟化硅挥发除去,碳被氧化分解或生成微小碳粒从而达到铝完全释放。在酸性溶液中加入铬天青S显色剂,然后调节溶液pH值为5.7~6.0,在室温条件下静置30min,即可使铝完全生成稳定的络合物,达到最佳分析效果。实验结果表明,通过在系列标准溶液中进行锰、铁基体匹配,同时在系列标准溶液和样品测量溶液中加入EDTA-Zn作掩蔽剂,并针对不同锰、铁含量的样品显色溶液,以氟化铵络合铝抑制其显色,配制专门的参比溶液,再将测得的吸光度减去试剂空白显色吸光度,可以消除锰、铁基体效应的影响。在铝的校准曲线线性范围内,线性相关系数可达0.9998,铝的检出限为0.0075%,定量限为0.025%。实验方法用于锰铁合金、锰硅合金、金属锰中铝的测定,结果的相对标准偏差(RSD,n=11)为6.3%~8.1%,回收率为94%~107%。按照实验方法测定锰硅合金标准样品YSB C 26605-2013中铝,测定结果与认定值相吻合;向锰硅合金标准样品YSB C 26605-2013中加铝标准溶液配制锰硅合金合成样品,按照实验方法进行测定,结果与参考值基本一致。选择6个实验室按照实验方法对锰铁合金、锰硅合金中铝进行测定,结果的相对标准偏差为2.0%~4.6%,平均值与电感耦合等离子体质谱法基本一致;按照实验方法测定金属锰中铝,测定结果与电感耦合等离子体质谱法相符。     

铬天青S分光光度法测定锰铁合金、锰硅合金、金属锰中铝

铝在锰铁合金、锰硅合金、金属锰中属于有害元素,在后续钢铁冶炼中易形成夹杂物而使钢铁材料变脆,为此建立了铬天青S分光光度法测定锰铁合金、锰硅合金和金属锰中铝的方法。以硝酸、氢氟酸分解样品,利用高氯酸冒烟提供高温和强氧化作用,硅与氢氟酸反应生成四氟化硅挥发除去,碳被氧化分解或生成微小碳粒从而达到铝完全释放。在酸性溶液中加入铬天青S显色剂,然后调节溶液pH值为5.7~6.0,在室温条件下静置30min,即可使铝完全生成稳定的络合物,达到最佳分析效果。实验结果表明,通过在系列标准溶液中进行锰、铁基体匹配,同时在系列标准溶液和样品测量溶液中加入EDTA-Zn作掩蔽剂,并针对不同锰、铁含量的样品显色溶液,以氟化铵络合铝抑制其显色,配制专门的参比溶液,再将测得的吸光度减去试剂空白显色吸光度,可以消除锰、铁基体效应的影响。在铝的校准曲线线性范围内,线性相关系数可达0.9998,铝的检出限为0.0075%,定量限为0.025%。实验方法用于锰铁合金、锰硅合金、金属锰中铝的测定,结果的相对标准偏差(RSD,n=11)为6.3%~8.1%,回收率为94%~107%。按照实验方法测定锰硅合金标准样品YSB C 26605-2013中铝,测定结果与认定值相吻合;向锰硅合金标准样品YSB C 26605-2013中加铝标准溶液配制锰硅合金合成样品,按照实验方法进行测定,结果与参考值基本一致。选择6个实验室按照实验方法对锰铁合金、锰硅合金中铝进行测定,结果的相对标准偏差为2.0%~4.6%,平均值与电感耦合等离子体质谱法基本一致;按照实验方法测定金属锰中铝,测定结果与电感耦合等离子体质谱法相符。     

EDTA滴定法快速测定铝锰合金中铝

采用定量的氯化钡与氢氧化钠一次性沉淀分离铝锰合金中的锰、铁等干扰元素 ,代替以往的先以六次甲基四胺分离锰 ,再以氢氧化钠分离铁的二次沉淀分离 ,然后用EDTA滴定法测定铝量     

EDTA络合滴定法连续测定铁矿石中铝铅锌

试样经盐酸、硝酸溶解后,加硫酸加热至冒浓白烟,在稀硫酸介质中,使铅生成硫酸铅沉淀,沉淀用乙酸-乙酸钠缓冲溶液溶解后,以二甲酚橙为指示剂,用EDTA络合滴定法测定铅,然后向滤液中加入过量氢氧化钠溶液,在pH>12强碱介质中,使滤液中的铁、锰、镍等离子生成沉淀,而铝、锌则以偏铝酸盐和偏锌酸盐存在于溶液中,从而使铝、锌与铁、锰、镍等离子分离。分取滤液两份,分别将溶液调至微酸性后加入pH5.5～6.0乙酸-乙酸钠缓冲溶液,在一份溶液中加入相应的掩蔽剂,以二甲酚橙为指示剂,用EDTA络合滴定法测定锌;在另一份溶液中加入过量EDTA标准溶液,使之与溶液中的铝、锌等金属离子络合,以二甲酚橙为指示剂,用氯化锌标准溶液滴定过量的EDTA标准溶液,然后用氟化钾破坏EDTA-Al络合物,再用氯化锌标准溶液回滴释放出来的EDTA,从而间接测定铝。用本方法对铁矿石标准样品中的铝、铅、锌进行测定,测定结果的相对标准偏差在1.2 %～2.5 %之间,且测定值与认定值相符。     

EDTA容量法测定铝、钙、镁时钒、钛、锰、铬、的允许量

钒、钛、锰、铬等元素,对EDTA容量法测定铝、钙、镁都有不同程度的干扰.钛定量干扰测定铝.钒(V)与PAN或二甲酚橙指示剂生成红色络合物,对测定铝的终点判断带来严重困难.锰使滴定铝的终点提前使结果偏低.铬(Ⅲ)和EDTA形成紫色络合物,影响铝、钙、镁滴定终点判断.当钛量高时,由于水解产生的沉淀吸附钙离子,使结果偏低.锰封闭滴定钙的指示剂.pH=10时,微克量的钛就使铬黑T指示剂封闭.钒(V)和钒(Ⅳ)在络合滴定镁时,使铬黑T指示剂终点返回.锰(Ⅱ)在 pH=10时和镁一起被EDTA络合,使结果偏高.     

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.