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钨精矿部颁标准分析方法中硅。钙是分别测定的。现我们改为连续测定,精简了操作,节省了试剂及人力,符合多、快、好、省的精神。矿样经焦硫酸钾分解以后,用草酸浸取,调整酸度为HC1 10%左右,过滤残渣以重量法测定硅。滤液及洗液合并加氨水调整pH至3～4,加草酸铵得草酸钙沉淀,过滤后与大量铁、锰、铜、铅、钨等分离。然后,加三乙醇胺掩蔽少量铁、铝,在pH大于12的碱性溶液中以钙黄绿素—百里酚酞为指示剂,用EDFA标准溶液滴定。
Tungsten concentrate ministerial standard analytical methods of silicon. Calcium was measured separately. Now we change to a continuous measurement, streamline the operation, saving reagents and manpower, in line with more, faster, better, the province’s spirit. After the sample is decomposed by potassium pyrosulphate, it is leached with oxalic acid and the acidity is adjusted to be about 10% HC1. The filtered residue is gravimetrically determined for silicon. The filtrate and washings were combined with aqueous ammonia to adjust the pH to 3 to 4, add ammonium oxalate to precipitate calcium oxalate, and then be filtered and separated from a large amount of iron, manganese, copper, lead and tungsten. Triethanolamine was then masked to a small amount of iron, aluminum and titrated with EDFA standard solution using calcein-thymolphthalein as an indicator in an alkaline solution having a pH greater than 12.