【摘要】 试样在750℃灼烧40 min,以Na2CO3与Na2B4O7混合熔剂高温熔融处理,采用动物胶重量法测定SiO2含量,然后将滤液制成母液,用三乙醇胺掩蔽铁(Ⅲ)、铝(Ⅲ)的干扰,以EDTA滴定法测定CaO和MgO的含量。对沉淀的条件进行了选择,由于滤液中已除去硅酸,避免了二次沉淀分离。方法用于连铸保护渣中SiO2,CaO和MgO的测定,相对标准偏差分别为0.35%~0.44%,0.38%~0.51%和1.91%~2.25%;与标准方法测定结果相符合。更多还原

【Abstract】 Systematic method for analysis of SiO2,CaO,MgO in continuous casting protective slag was studied.Sample speciments were pretreated by ignition at 750 ℃ for 40 min and then melt in mixed flux of Na2CO3 and Na2B4O7 at high temperature.The content of SiO2 was determined by animal glue gravimetric method.After the filtrate was prepared into mother liquid,the content of CaO and MgO was determined by EDTA titrimetry using triethanolamine as the masking agent for Fe and Al.The conditions of precipitation were also investigated.Since silicic acid had been removed from the filtrate,secondary precipitation separation could be avoided.The method had been applied to the determination of SiO2,CaO and MgO in continuous casting protective slag with the relative standard deviation of 0.35%-0.44%,0.38%-0.51% and 1.91%-2.25%,respectively.The determination results were accordant with those obtained by the national standard method.更多还原