Combined Photometric Determination of Manganese and Phosphorus in High Carbon Ferric-manganese Alloy
Duan Ping-Chang
(Cnbm Kaisheng Zhonggong Co.,Ltd,Quality Guaranteed Department,Huainan 232058 China)
Abstract :Two elements (manganese and phosphorus) in high carbon ferro-manganese alloy were determined by combined absorptiophotometric method .In this determining process, high carbon ferro-manganese alloy was sampled and solubilized for only once .The methed is simple ,rapid and easy to operate .The cost of analysis is lower .The accuracy and practicality are better .It has filled the gap in the mothed of combined absorptiophotometric determination of manganese and phosphorus in high carbon ferro-manganese alloy , too .
Key words :Photometry ;Combined absorptiophotometric absorptiophotometric determination ;High carbon ferro-manganese alloy ;Manganese and phosphorus
锰铁作为合金元素添加剂和炼钢脱氧、脱硫剂,是钢铁和铸造行业最常用的铁合金之一。尤其是高碳锰铁,因其相对于中、低碳锰铁来说,价格较为低廉,所以它的应用最为普遍。高碳锰铁的质量优劣,一般是以C、Mn、P三个元素的含量来鉴别。对于碳元素,可用微机碳硫自动分析仪快速测定之;而对于锰、磷元素,常用硝酸铵氧化三价锰滴定法和磷钒钼黄光度法分别单独称样测定【1~3】,此二法溶样环节皆需冒烟处理,空气污染较大,毒害作用较强,操作手续较复杂且不易掌握,而且需两次称样溶解,既费时费事,又浪费成本。笔者经大量查阅资料和实验探索,采用光度法,实现了一次称样溶解联合测定高碳锰铁中Mn、P两个元素的目的,方法简便、快速、易操作,结果准确性好,分析成本低,生产实用性强,并且填补了仅需一次称样溶解用光度法可联合测定高碳锰铁中Mn、P两个元素的方法空白,为快速鉴别高碳锰铁的质量等级寻找了一条捷径。
1 主要仪器与试剂
721E型分光光度计
HNO3(1+3);三乙醇胺溶液(1+4);EDTA溶液(0.1mol/L):称取乙二胺四乙酸二鈉3.7226g溶解于100ml水中;KOH溶液:20%;KMnO4溶液:4%;NaNO2溶液:2%;钼酸铵—酒石酸钾钠溶液:钼酸铵溶液(10%)和酒石酸钾钠溶液(10%)等体积混匀;NaF—SnCl2溶液:每100ml氟化钠溶液(2.4%)中溶解0.2g氯化亚锡,摇匀。
2 分析方法
称取制备的200目试样0.1000g于125ml的三角瓶中,加入HNO3(1+3)40ml,在电炉上低温加热至试样完全溶解后,煮沸驱除氧化氮黄烟,取下冷却,以水定容于50ml容量瓶中,摇匀。
(1)锰显色试液 分取母液2ml于300ml烧杯中,加三乙醇胺溶液15ml,EDTA溶液10ml,KOH溶液10ml,通氧1~2min(或充分摇动3~5min)。
(2)磷的测定 分取母液15ml于150ml锥形瓶中,滴加KMnO4溶液3~4滴,使试液呈稳定的红色,在电炉上加热并煮沸至试液中有棕色MnO2沉淀生成,滴加NaNO2溶液至试液恰好变清,煮沸驱除氮氧化物,取下,加钼酸铵—酒石酸钾钠溶液10ml,摇匀,加NaF—SnCl2溶液40ml,摇匀,用1cm比色皿,以水为参比,在680nm波长处测吸光度A磷。
(3)在测定磷后,将锰显色试液用1cm比色皿,以水为参比,在630nm波长处测吸光度A锰。
3 分析结果
为验证方法的可靠性和准确度,分别采用本法和单独称样的厡方法对4个不同的高碳锰铁样品进行对比测定,分析结果见表1:
表1 样品分析结果(ω%)
序号
|
样品
|
原方法测得值
|
|
本法测得值
|
|
标准值
|
|
|
Mn
|
P
|
|
Mn
|
P
|
|
Mn
|
P
|
1
|
YSBC 18602-08
|
64.51
|
0.191
|
|
64.53
|
0.192
|
|
64.78
|
0.194
|
|
高碳锰铁
|
|
|
|
|
|
|
|
|
2
|
84-13 锰铁
|
66.03
|
0.329
|
|
66.01
|
0.330
|
|
66.28
|
0.325
|
|
|
|
|
|
|
|
|
|
|
3
|
GBW 01124
|
73.20
|
0.160
|
|
72.68
|
0.163
|
|
72.96
|
0.162
|
|
高碳锰铁
|
|
|
|
|
|
|
|
|
4
|
YSBC 11602-99
|
73.62
|
0.153
|
|
73.98
|
0.151
|
|
73.88
|
0.152
|
|
高碳锰铁
|
|
|
|
|
|
|
|
|
实验证明,本法无需冒烟处理试样,操作步骤简单、易掌握,分析速度较快,结果准确度较高,分析成本较低,大气污染较小,生产实用性很强。
4 说明
(1)本法测定锰的机理是Mn2+在碱性三乙醇胺介质中,能被空气氧化生成绿色的Mn3+与三乙醇胺络合物。
(2)KOH的加入量须将酸中和以后,尚过量浓度达0.1mol/L以上。
(3)本法测定磷适当加大了NaF和SnCl2的用量,以提高磷显色试液的色泽稳定性。
(4)硅对测定磷的干扰用酒石酸钾钠消除之;砷含量小于0.3%时不干扰磷的测定。
参 考 文 献
【1】 徐盘明,赵祥大. 实用金属材料分析方法[M].合肥:中国科学技术大学出版社,1990.
【2】 吴诚,等. 机械工程材料测试手册(化学卷)[M].沈阳:辽宁科学技术出版社,1996.
【3】 鄢国强. 工厂实用化学分析手册[M].北京:机械工业出版社,1995.
Combined Photometric Determination of Manganese and Phosphorus in High Carbon Ferric-manganese Alloy
Duan Ping-Chang
(Cnbm Kaisheng Zhonggong Co.,Ltd,Quality Guaranteed Department,Huainan 232058 China)
Abstract :Two elements (manganese and phosphorus) in high carbon ferro-manganese alloy were determined by combined absorptiophotometric method .In this determining process, high carbon ferro-manganese alloy was sampled and solubilized for only once .The methed is simple ,rapid and easy to operate .The cost of analysis is lower .The accuracy and practicality are better .It has filled the gap in the mothed of combined absorptiophotometric determination of manganese and phosphorus in high carbon ferro-manganese alloy , too .
Key words :Photometry ;Combined absorptiophotometric absorptiophotometric determination ;High carbon ferro-manganese alloy ;Manganese and phosphorus