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利用氟硅酸钾溶解于沸水中生成氢氟酸的原理。试样以硝酸、氢氟酸溶解,硅转化为硅氟酸,加入硝酸钾生成氟硅酸钾沉淀。经过滤、洗涤沉淀中的游离酸后,溶解于中性沸水中,生成氢氟酸,以溴麝香草酚蓝为指示剂,用氢氧化钠标准溶液滴定游离出的氢氟酸,借此测定硅锰铝合金中硅含量,其相对标准偏差小于0.0796%。 相似文献
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介绍了一种以可定量测定的滤光片为参比的硅钼蓝示差分光光度法。在浓硝酸中加15%的硝酸钾保护剂,60~70℃水浴溶解试样并加入尿素除去低级氮氧化物,对比试验确定吸取液体积,并简化为"一点法",用单标样实际吸光度值换算求得硅含量。结果表明,该法测定误差在国家标准允许差范围内,是一种准确、快速、有效的方法。 相似文献
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采用无水碳酸钠与硝酸钾混合熔剂代替过氧化钠等强碱性熔剂测定高碳铬铁中硅的含量,样品在镍坩埚中860℃熔融10min,能够完全熔解,无残余,熔块易于浸取。采用钼蓝法进行硅的测定,解决了氢氧化钠、氢氧化钾、过氧化钠等熔剂因含有空白值对低含量硅测定结果造成的不良影响。 相似文献
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将经典的氟硅酸钾碱滴定法改为硅钼蓝光度法快速测定硅。试样用硝酸和氢氟酸溶解,多余的氢氟酸用饱和硼酸溶液配合,在一定酸度下,加入钼酸铵与硅酸生成黄色的硅钼杂多酸,再加入草酸以破坏磷等与钼酸铵形成的杂多酸并络合三价铁,最后加入硫酸亚铁铵将硅钼黄还原为硅钼蓝,然后用分光光度法测定硅含量的方法。实验结果表明,在0.1~0.6mol/L的酸度下,正硅酸与钼酸铵生成硅钼杂多酸,选择硅钼蓝的吸收波长在660nm处,表观摩尔吸光系数为ε=8.69×103L·mol-1·cm-1,Si的浓度在0~500mg/100mL范围内符合比尔定律,相关系数r=0.9998。本方法应用于硅铬合金中硅含量的测定,方法选择性强,且缩短了分析周期。 相似文献
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通过对高硅锰硅合金生产过程的分析,找出制约连续生产的限制性环节,并提出了解决设备损坏和出铁口侵蚀的方案,以及工艺过程控制的关键,从而保证高硅锰硅合金的连续生产。 相似文献
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铝硅合金低温加硅研究 总被引:1,自引:0,他引:1
扼要介绍了铝硅合金生产中的五种熔配工艺,以共晶型与过共晶型两种不同牌号的铝硅合金为例阐述了低温加硅熔炼技术,获得了最佳工艺,该方法质量稳定、节约能源、环境友好。 相似文献
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论述了在高硅锰硅合金生产中,通过控制炉温的时间及采用合理的炉渣碱度制度,提高合金中硅含量,以得到稳定的高品级的高硅锰硅合金。 相似文献
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<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 相似文献
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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, 相似文献
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《China Nonferrous Metals Monthly》2014,(10)
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 相似文献
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《China Nonferrous Metals Monthly》2014,(10)
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 相似文献
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《China Nonferrous Metals Monthly》2014,(10)
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, 相似文献
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《China Nonferrous Metals Monthly》2014,(12)
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. 相似文献
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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. 相似文献
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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. 相似文献