GOST 23862.19-79
GOST 23862.19−79 Rare-earth metals and their oxides. Method of determining titanium (with Change No. 1)
GOST 23862.19−79
Group B59
INTERSTATE STANDARD
RARE EARTH METALS AND THEIR OXIDES
Method of determining titanium
Rare-earth metals and their oxides. Method of determination of titanium
ISS 77.120.99
AXTU 1709
Date of introduction 1981−01−01
The decision of the State Committee USSR on standards on October 19, 1979 N 3989 date of introduction is established 01.01.81
Limitation of actions taken by Protocol No. 7−95 Interstate Council for standardization, Metrology and certification (ICS 11−95)
EDITION with Change No. 1, approved in April 1985 (IUS 7−85).
This standard specifies the extraction-photometric method for the determination of titanium (5·10% up to 1.5·10
%) in rare earth metals and their oxides (except cerium and its dioxide).
The method is based on extraction with chloroform ternary complex titanium-diantipyrylmethane tin from hydrochloric acid solution with subsequent measurement of optical density of the extract on the photoelectrocolorimeter.
(Changed edition, Rev. N 1).
1. GENERAL REQUIREMENTS
1.1. General requirements for method of analysis according to GOST 23862.0−79.
2. APPARATUS, REAGENTS AND SOLUTIONS
Photoelectrocolorimeter FEK-56 or similar device.
Muffle furnace with thermostat providing temperatures up to 900 °C.
Tile electric.
Cup platinum or quartz with a capacity of 100 cm.
A quartz crucible (or platinum) with a capacity of 40−50 cm.
Measuring cylinders with capacities of 10, 20 and 50 cm.
Volumetric flasks with a capacity of 200 and 1000 cm.
Pipettes with a capacity of 1, 5, 10 and 15 cm.
Conical flasks with a capacity of 100 cm.
Glasses glass with a capacity of 100 cm.
Funnels, conical.
Filters red ribbon.
Potassium preservatory according to GOST 7172−76, h.d. a.
Diantipyrylmethane, h. e. a., a solution with a concentration of 20 g/DM2 mol/DM
hydrochloric acid.
Tin dichloride in NTD, h, a solution with a concentration of 200 g/DM2 mol/DM
hydrochloric acid.
Chloroform, h.d. a.
Hydrochloric acid of high purity according to GOST 14261−77, 12; 6; 4 and 2 mol/DMsolutions.
Tartaric acid according to GOST 5817−77, h. e. a., a solution with a concentration of 150 g/DM.
The water is deionized.
Titanium dioxide, C. D. and.
A standard solution of titanium (spare) containing 1 mg/cmtitanium: a sample of titanium dioxide ground 0,3336 g is placed in a platinum or quartz Cup with a capacity of 100 cm
, add 4 g of potassium persulfate, put the Cup in a muffle furnace, and fuse the mixture at 800−900 °C to produce a clear float. The cooled melt is dissolved in 60 cm
of tartaric acid solution, transferred to a volumetric flask with a capacity of 200 cm
and the volume was adjusted to the mark with water.
A solution of titanium (working) containing 1 µg/cmtitanium, is prepared by diluting 1 cm
of a standard solution of titanium (1 mg/cm
) 1000 times with a solution of 4 mol/DM
of hydrochloric acid.
3. ANALYSIS
3.1. A portion of the sample mass of 0.1−3.0 g (depending on the content of titanium) is placed in a beaker with a capacity of 100 cm, flow 20 cm
6 mol/l
hydrochloric acid and dissolved by heating. After cooling the solution was filtered through a filter «red ribbon», washed with 10 cm
6 mol/DM
of hydrochloric acid, then 25 cm
of water. The resulting filtrate 1 kept. The filter with precipitate was placed in a quartz crucible with a capacity of 50 cm
, dried on a hotplate and burned in a muffle furnace. To the residue in the crucible add 0.5 g of potassium pyrosulphate and fused at 600−700 °C until a clear melt. The smelt is cooled and dissolved in the filtrate was 1. The crucible is washed 5−7 cm
of water, adding her to the obtained solution. The solution was poured 15 cm
solution diantipyrylmethane and then do as under construction of calibration curve.
Simultaneously with the samples through all stages of the analysis carried out control experience in chemicals. The obtained value of optical density is subtracted from the value of optical density of test solution. The optical density of the solution should not exceed 0.10; otherwise, change the reagents.
The mass of titanium in the sample find for the calibration schedule.
(Changed edition, Rev. N
1).
3.2. Construction of calibration curve
In eight glasses with a capacity of 100 cmadministered 1,0; 3,0; 5,0; 7,0; 9,0; 11,0; 13,0; 15,0 cm
working solution (containing 1 µg/cm
of titanium), poured 15 cm
diantipyrylmethane solution and the volume was adjusted to 50 cm
of 2 mol/DM
hydrochloric acid solution. After 20−30 min the solutions were transferred to a separating funnel with a capacity of 150 cm
, 30 cm, pour the
solution of dichloride of tin, 15 cm
of chloroform and extracted titanium by shaking the funnel for 1 min. After separation of the liquids, the organic layer was filtered through a dry filter red ribbon in a cuvette with the thickness of the light absorbing layer 30 mm and measure the optical density of solutions on the photoelectrocolorimeter at
In one of the glasses introduce all reagents except the solution of titanium (zero solution). The optical density of the zero solution should not exceed 0.05; otherwise, change the reagents. The value of optical density of the zero solution is subtracted from the values of optical densities of standard solutions.
The definition is repeated at least five times.
The found average values of optical densities and their corresponding masses of the Titan build calibration curve, causing the y-axis the value of the optical density of the solution, and on the x — axis is the mass of titanium in micrograms.
4. PROCESSING OF THE RESULTS
4.1. Mass fraction of titanium () in percent is calculated by the formula
where is the mass of titanium, was found in the calibration schedule, mcg;
— the weight of the portion of the sample,
The result of the analysis take the average of results of two parallel measurements.
4.2. The discrepancy between the results of two parallel determinations or the results of the two tests should not exceed the values permitted discrepancies listed in the table.
| Mass fraction of titanium, % |
Allowable difference, % |
5·10 |
2,5·10 |
2·10 |
1,0·10 |
1,5·10 |
0,5·10 |
4.1, 4.2. (Changed edition, Rev. N 1).
