GB/T 4701.1-1984 Chemical analysis methods for ferrotitanium - Ammonium ferric sulfate volumetric method for determination of titanium content
Some standard content:
National Standard of the People's Republic of China
Methods for chemical analysis of ferrotitaniumThe ammonium ferric sulfate volumetric method forthe determination of titanium contentThis standard is applicable to the determination of titanium content in ferrotitanium. Determination range: 20.00～80.00%. UDC 669.15' 295
:543.24±546
GB 4701.1--84
ISO7692-1988
This standard complies with GB1467-78 "General Principles and General Provisions for Chemical Analysis Methods of Metallurgical Products". This standard is equivalent to the international standard ISO7692-1983 (Titanium Ferro-Determination of Titanium Content-Titration Method). 1 Method Summary
The sample is dissolved with sulfuric acid, hydrofluoric acid, nitric acid and panic acid. If there are interfering elements such as chromium, vanadium, molybdenum and tin, titanium hydroxide can be precipitated and separated from the interfering elements in the presence of hydrogen peroxide. Titanium is reduced to trivalent with metallic aluminum in a carbon dioxide or nitrogen atmosphere. With sulfur fluoride as the indicator, titrate with standard ammonium ferric sulfate solution. 2 Reagents
2.1 Aluminum (purity above 99.5%), thickness 0.10mm, aluminum foil without titanium. When using, fold 1 piece of aluminum foil to a length of about 3-4cm and a width of about 1 cm rectangle. wwW.bzxz.Net
2.2 Sodium bicarbonate.
2.8 Nitric acid (specific gravity 1.42).
Sulfuric acid (specific gravity 1.84).
2.5 Hydrochloric acid (specific gravity 1.19).
Hydrofluoric acid (specific gravity 1.15).
Sulfuric acid (1 +1).
2.B Sulfuric acid (1 +4).
2. 9 Sodium hydroxide solution (10%).
Sodium hydroxide solution (2%).
Ammonium thiocyanate solution (10%).
2.12 Nitrogen: oxygen-free (oxygen less than 10 ppm by volume), purity 99.998% or carbon monoxide of similar purity. 2.13 Hydrogen peroxide solution (specific gravity 1.10). 2.14 Ferrous sulfate solution
Weigh 2g of pure iron, dissolve in 50ml of hydrochloric acid (2.5), add 10ml of nitric acid (2.3) to oxidize, add 40ml of sulfuric acid (2.7), heat until sulfuric acid fumes appear, cool, dilute to 200ml with water, boil for about 15 minutes, cool and transfer to 50 0ml volumetric flask, dilute to scale with water, and mix well.
2.15 Titanium standard solution
Weigh 0.8340g of titanium dioxide (purity of 99.9% or more) pre-calcined at 800℃ for 2h, place in a platinum crucible with a platinum cover, add 10g of potassium pyrosulfate and melt carefully, take out and cool, place in a 400ml beaker, add 50ml sulfuric acid (2.8), 100ml warm water, heat carefully on a low-temperature electric furnace to leach the melt, take out the platinum, wash with water, continue to heat until the solution is completely clear, cool, and transfer to the National Bureau of Standards. Issued on October 4, 1984
Implementation on September 1, 1985
GB 4701.1—84
1000ml volumetric flask, dilute to scale with water, and mix. This solution contains 0.5mg titanium in 1ml. 2.16 Ammonium ferric sulfate standard solution
2.18.1 Preparation
Weigh 10.2g ammonium ferric sulfate [FeNH(SO>z·12H,O], place it in a 400ml beaker, add 100ml water and 50ml sulfuric acid (2.7), after dissolution, transfer it to a 1000ml volumetric flask, dilute to scale with water, and mix. 2.16.2 Calibration
Pipette 50.00ml titanium standard solution (2.15), place it in a 500ml conical flask, add 5ml sulfuric acid (2.7) and 180ml hydrochloric acid (2.5), and proceed as per 5.3.4~5.3.6. Perform a blank test at the same time.
The titer of ammonium ferric sulfate standard solution on titanium is calculated according to the following formula. In the formula, 7—
—1 ml of ammonium ferric sulfate standard solution is equivalent to the amount of titanium, the amount of titanium removed, g;
V,—-the volume of ammonium ferric sulfate standard solution consumed during calibration, mlV——the volume of ammonium ferric sulfate standard solution consumed during blank test, ml. 3 Instruments
3.1 Bunsen valve or covered funnel
The Bunsen valve (see Figure 1) consists of a rubber stopper (1), which passes through two glass tubes (2 and 6). The rubber tube (3) is connected to the glass tube and the upper end is closed with a glass stopper (5).
Use a blade to cut a 10-15 mm long incision (4) in the middle of the rubber tube (3) above the glass tube (2). The lower end of the glass tube (6) is about 5 cm above the horizontal surface of the solution to be measured, and nitrogen or carbon monoxide gas is introduced to replace the gas in the bottle and release the meter from the rubber tube (3).
3.2 Magnetic stirrer with a stirring rod wrapped with polytetrafluoroethylene. 3.3 Titration device in nitrogen atmosphere (see Figure 2). 4 Sample
Figure 1 Bunsen valve
GB 4701.1--B4
Figure 2 Nitrogen protection titration device
1-Rubber plug 2-Glass tube, 3-Rubber tube; 4-Incision: 5-Glass plug
The sample should pass through a 0.125 mm sieve.
5 Analysis steps
5.1 Sample quantity
Weigh 1.0000g of sample.
5.2 Blank test
Carry out a blank test with the sample.
6.8 Determination
6.3.1 Preparation of test solution
1-500ml conical flask, 2-chlorine inlet 13-nitrogen outlet, 4-burette
Put the sample (5.1) in a 250ml polytetrafluoroethylene beaker, add 20ml water and 35ml sulfuric acid (2.7), when the reaction is slow, add 20ml hydrochloric acid (2.5) and 1ml hydrofluoric acid (2.6), with polytetrafluoroethylene Cover the beaker with fluoroethylene table blood, slowly add 5ml nitric acid (2.3) to oxidize while cooling, remove the table blood after the reaction is complete, heat until sulfuric acid smoke appears, continue heating for about 5min, remove and cool, add 30ml hydrochloric acid (2.5), stir carefully, cover: polytetrafluoroethylene table blood, heat until the solution is clear, remove, wash the table dish with 5ml hydrochloric acid (2.5), cool and transfer to a 500ml volumetric flask, dilute to the scale with water, and mix well. 5.8.2 No interfering elements
If the titanium content in the sample is expected to be 20~45%, transfer 50.00ml test solution (5.3.1), if the titanium content is 45~75%, transfer 25.00ml test solution (5.3.1). Place the test solution in a 500ml conical flask, add 85ml hydrochloric acid (2.5) and 25ml water, and proceed as per 5.3.4 and 5.3.5 or 5.3.4 and 5.3.6. 5.3.3 Separation of interfering elements
If the titanium content in the sample is expected to be 20~45%, transfer 50.00ml of the test solution (5.3.1); if the titanium content is 45~75%, transfer 25.00ml of GB 4701.1-04
test solution (5.3.1). Place the test solution in a 250ml beaker containing 10ml ferric sulfate solution (2.14), add 50ml sodium hydroxide solution (2.9) and 2ml hydrogen peroxide solution (2.13), heat and boil for 5min, remove and wait for the precipitate to sink, filter it with double-layer quick filter paper, and then transfer the precipitate to the filter paper. Wash the beaker and the precipitate 6 times with about 10ml sodium hydroxide solution (2.10) each time, then wash the filter paper and the precipitate with sodium hydroxide solution (2.10), wash the funnel jaw with water, and then place the funnel in a 500ml conical flask 1, add 45ml hydrochloric acid (2,5) and 15ml sulfur (2.8) to the original 250ml beaker 4, heat to 60~70℃, and add this mixed acid to the filter paper 6 times to dissolve the precipitate (each time, wait until the acid solution has drained out before adding the next time). Then wash the filter paper three times with 35 ml of 60-70℃ hydrochloric acid (2.5), and finally wash the beaker, filter paper and funnel neck with no more than 40 ml of 70-80℃ water. The following is carried out according to 5.3.4 and 5.3.5 or 5.3.4 and 5.3.6.
Reduction of 5.3.4
Add 2g of sodium bicarbonate (2.2) and 4g of aluminum foil (2.1) to the test solution (5.3.2 or 5.3.3), and immediately cover it with a Bunsen valve or a cover funnel filled with saturated sodium bicarbonate solution. The solution should be stirred continuously during the reduction. Note that at the end of the reduction, negative pressure is generated in the cover funnel, so saturated sodium hydrogen iodide solution must be added. 5.8.5 Titration in nitrogen atmosphere
Before the lead is completely dissolved, remove the rubber (3) at the upper end of the Bunsen valve downtube (6), then connect the downtube (6) to nitrogen and adjust the nitrogen flow rate to 0.7±0.11/min. When the aluminum is completely dissolved (bubbles stop), immerse the conical flask in cold water and allow nitrogen to escape from the cut of the rubber tube (3) until the solution reaches room temperature (about 7 minutes). While continuing to pass nitrogen, remove the Bunsen valve, add 10ml of ammonium thiocyanate solution (2.11) and a magnetic stirring bar (see 3.2), rinse the downtube (6) with boiled cold water, replace the Bunsen valve with a titration device connected to nitrogen (see Figure 2), place it on a magnetic stirrer (see 3.2), and then titrate with ferric sulfate plating standard solution (2.16) until a stable red color is reached, which is the end point.
5.3.6 Titration in carbon dioxide atmosphere
After aluminum is dissolved, cool to room temperature with cold water, remove the Bunsen valve or cover funnel, add 10ml of ammonium thiocyanate solution (2.11), and titrate with ammonium ferric sulfate standard solution (2.16) until a stable red color is obtained, which is the end point. 6 Calculation of analysis results
Calculate the percentage of titanium according to the following formula:
Ti (%) =
T.(V2-Vo2)
Where: 7——1ml ammonium ferric sulfate standard solution is equivalent to ten titanium, g3V—volume of ammonium ferric sulfate standard solution consumed by the test solution during titration, ml, ×100
Vp2—volume of ammonium ferric sulfate standard solution consumed along with the sample blank during titration, ml; mn——sample volume, g
rTest solution fraction ratio.
Analysis results are expressed to two decimal places. 7 Allowable difference
The difference in analysis results between laboratories should not be greater than the allowable difference listed in the following table. %
Titanium content
20.0040.00
>40.00-80.00
Allowable difference
Additional instructions:
GB 4701.1-84
This standard is proposed by the Ministry of Metallurgy of the People's Republic of China. This standard was drafted by Jinzhou Ferroalloys of the Ministry of Metallurgy. From the date of implementation of this standard, the former Ministry of Metallurgy Standard YB581-65 "Chemical Analysis Method of Titanium" will be used.
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