The percentage of iron in the titanium plate analysis method

Determination of titanium content of pig iron , general sample dissolution with sulfuric acid , nitric oxide , methane two diantipyrine spectrophotometry . In actual production , refining steel silicon content is not high , to the determination of silicon content in pig iron titanium is generally 0.50o / c ~ 0.70%. Can refer to the determination of titanium steel , acid-soluble salt samples directly , hydrogen peroxide , acid when adding color color , color accelerate the reaction rate . This test uses standard pig iron produced by the Panzhihua Iron and Steel Institute , the titanium content was 0.043% , 0.066% , 0.078% , 0.150% , 0.225% and 0.237% .

l Test Methods
1.1 Reagents and Instruments
Hydrochloric acid and p = 1.19g/ml
Hydrogen peroxide w (H202) = 30%
1% ascorbic acid solution
Chromotropic acid solution 1% ( chromotropic acid 1g, 5g ascorbic acid dissolved in 100ml of water and shake )
Two diantipyrine methane solution of 1% [ per 100mlHCI (1 +
1O) added 1g two diantipyrine methane ]
721 spectrophotometer

1.2 Analysis Methods

Sample Weigh 0.05g, placed 5Om1 dual vial , 5ml of hydrochloric acid were dissolved by heating . After the dissolution of the sample basically remove , add 1.5ml hydrogen peroxide coolish , reheating the sample is completely dissolved and evaporated to near dryness . Add 5ml of water , 20ml ascorbic acid solution , 2ml Chromotrope Rongrong , 5ml two diantipyrine chloride solution , diluted with water to the mark,
Shake well , dry with absorbent cotton filter . At 510nm wavelength, with 3cm cuvette with water as a reference, the absorbance was measured with a 721 spectrophotometer .

1.3 Work curve plotted
Respectively, with a titanium content of 0.043% , 0.15% , 0,237 % of
Standard iron , a method of operating at 1.2 , measured absorbance are shown in Table
Table 1 iron standard sample absorbance measured values
According to Table 1, the calibration curve data is plotted in Figure 1.

2 test data and analysis
2.1 Test Data Analysis
By 1.2 test method, the addition of three different titanium content of raw
Sample test repeated iron , based on the measured absorbance from Figure 1
Richard results are listed in Table 2 . According GBT223.16-91, National
Tolerance r:
lgr = a 1.5359 +0.80131 gm
Suitable titanium content of O. O1% ~ 2.4%.
2.2 Analysis of test results
1 ) the determination of titanium , the sample decomposition is an important part. Because the color is sulfuric acid or hydrochloric acid medium , using sulfuric smoke treatment is routine operation, but with a small amount of sulfuric smoke operations more difficult to master , easy to form insoluble salt precipitation , resulting in the failure analysis . So this experiment, a hydrochloric acid sample decomposition of hydrogen peroxide , so not only speed up the operation and avoid the muddy appearance .

2 ) sample dissolution process of hydrogen peroxide can be added or applied too early , otherwise it will lead to surface oxidation sample , the sample can not be completely dissolved. Hydrochloric acid can not be too much if the amount of hydrochloric acid, must be evaporated to near dryness .
3 ) If the silicon content in the sample is too high, decomposition of hydrofluoric acid may be added medical titanium plates. In general , the silicon content of the steel smelting between 0.35% to 0.85 %, so this method is suitable for blast furnace analysis .
4 ) high iron , alum and chromotropic acid and two diantipyrine methane can be color , but can be masked with ascorbic acid to eliminate interference . 5ml of water before adding ascorbic acid to reduce the temperature to avoid ascorbic
Acid when exposed to heat decomposition.
5 ) single color with chromotropic acid , not only low sensitivity , poor reagent stability and reagents dark background , not water as a blank , not suitable for rapid analysis . Single with two diantipyrine methane, although higher sensitivity , but the reagent consumption, the most important is the reaction is slow , not suitable for rapid analysis . With chromotropic acid twelve diantipyrine color can complement both defects.

3 Conclusion
1 ) This method highlights the rapidly this feature , the original method was some improvement, the test results are satisfactory, in line with national standards allowable error .

2 ) The test is simple to operate, only 5min to analyze a sample of pig iron - 6min. Suitable for rapid analysis of blast furnace .

3 ) analysis of the test reference titanium steel titanium whole distributors, high silicon iron has certain limitations.