GOST 11930.5-79

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  ГОСТ 11930.5-79

GOST 11930.5−79 Materials surfacing. Methods for determination of manganese (with Amendments No. 1, 2)

GOST 11930.5−79

Group B09

INTERSTATE STANDARD

MATERIALS SURFACING

Methods for determination of manganese

Hard-facing materials. Methods of manganese determination

ISS 25.160.20
AXTU 1709

Date of introduction 1980−07−01

The decision of the State Committee USSR on standards on March 21, 1979 N 982 date of introduction is established 01.07.80

Limitation of actions taken by Protocol No. 4−93 of the Interstate Council for standardization, Metrology and certification (ICS 4−94)

REPLACE GOST 11930−66 in part of sec. 3

EDITION (August 2011) with Amendments No. 1, 2 approved in December 1984, December 1989 (IUS 3−85, 3−90)


This standard establishes photocolorimetric method for the determination of manganese (at a mass fraction of manganese from 0.4 to 6%) and volumetric method for the determination of manganese (at a mass fraction of manganese from 6 to 8.5%) in the surfacing materials.

1. GENERAL REQUIREMENTS

1.1. General requirements for methods of analysis GOST 11930.0−79.

2. PHOTOCOLORIMETRIC METHOD FOR THE DETERMINATION OF MANGANESE

2.1. The essence of the method

The method is based on oxidation of manganese in seriesfamily environment Periodica potassium to manganese acid, the colour intensity is measured on a photoelectrocolorimeter.

2.2. Apparatus, reagents and solutions

Types photoelectrocolorimeter FEK-56, FEK-56M or any other type.

Sulfuric acid GOST 4204−77, diluted 1:1 and 1:4.

Orthophosphoric acid according to GOST 6552−80.

Potassium cognately, a solution of 50 g of potassium jednolitego placed in a flask with a capacity of 500 cm, add 100 cmof water, 200 cmof sulphuric acid, mix, add 100 cmof phosphoric acid.

Selenous acid, on the other 6−09−5407−88* a solution with a mass fraction of 2%.
________________
* THAT are authoring. For additional information, please refer to the link. — Note the manufacturer’s database.

Manganese metal according to GOST 6008−90.

Purification of manganese: 10 g of manganese treated in a mixture consisting of 50 cmwater and 5 cmof nitric acid. After 6 times washing with water the metal is dried at room temperature.

A standard solution of manganese; prepared as follows: 0.1 g of metallic manganese is dissolved in 25 cmof nitric acid, diluted 1:1, boil to remove oxides of nitrogen and transferred into a measuring flask with volume capacity of 1000 cm. The solution was diluted to the mark with water and mix.

1 cmof the solution contains 0.0001 g of manganese.

2.3. Analysis

2.3.1. The manganese determined in the filtrate after separation of the silicon GOST 11930.3−79.

Of volumetric flasks with a capacity of 200 cmtaken from 5 to 50 cmof the analyzed solution (depending on manganese content) in a glass with a capacity of 100 cm, add 10 cmof a solution of potassium jednolitego. The contents of the flask diluted to 50 cmof distilled water and heated to boiling. The hot solution is left for 30 minutes to warm the tile until the complete development of color. The cooled solution is transferred to a volumetric flask with a capacity of 100 cm, diluted with distilled water to the mark, mix and measure the optical density of colored solution on a photoelectrocolorimeter with a green optical filter (490 nm) in a cuvette with a thickness of the absorbing layer is 50 mm For preparation of a solution of comparison, using the corresponding part of the investigated solution, in which manganese acid reduced addition (with stirring) a few drops of a solution of selenous acid.

2.3.2. Construction of calibration curve

Five volumetric flasks with a capacity of 100 cmplaced 1, 2, 3, 4, 5 cmstandard solution manganese 10 cmof a solution of potassium jednolitego and further analysis are as indicated in claim 2.3.1.

2.4. Processing of the results

2.4.1. Mass fraction of manganese () in percent is calculated by the formula

,

where is the mass of manganese was found in the calibration schedule g;

 — the mass of sample, g;

 — aliquota part of the analyzed solution, cm.

2.4.2. The difference between the largest and smallest results of the three parallel measurements, and the two results of the analysis at a confidence level of 0.95, should not exceed the values of permissible differences given in table.1.

Table 1

2.1, 2.3. (Changed edition, Rev. N 2).

3. VOLUMETRIC METHOD FOR DETERMINATION OF MANGANESE

3.1. The essence of the method

The method is suitable for analysis of a mixture of powders for surfacing.

The method is based on the oxidation of manganese to pneumococcal followed by titration it with a solution of salt Mora. Chrome pre-separated zinc oxide.

(Changed edition, Rev. N 2).

3.2. Reagents and solutions specified in clause 2.2 with the addition of:

Congo red.

Zinc oxide according to GOST 10262−73, turbid water zinc oxide is prepared as follows: 20−25 g finely powdered zinc oxide was triturated in a porcelain mortar with 50 cmof hot (50−60 °C) water to a paste and transfer into a glass with a capacity of 200 cm, adding 25 cmof water. Before use the mixture is well stirred with a glass rod to give it a uniform consistency.

3.3. Analysis

Of volumetric flasks with a capacity of 200 cmaccording to GOST 11930.3−79 taken in glass from 50 to 100 cmof the analyzed solution and evaporated to 25 cm. The solution was neutralized with a piece of paper, Congo hydroxide solution sodium hydroxide prior to the deposition of sediment, which is then dissolved by the addition of a few drops of sulphuric acid, diluted 1:4. The solution is heated to a temperature of 65−70 °C, transferred to a volumetric flask with a capacity of 100 cmand poured small amounts of turbid well water zinc oxide, carefully shake each time the contents of the flask until the bottom of the flask will be a small excess of zinc oxide. The contents of the flask are heated to 70−80 °C and allowed to stand for 5 min. the solution was Then cooled, diluted to the mark with water and mix. The solution was filtered, taken 50 cmin a conical flask with a capacity of 250−300 cm, neutralized with sulfuric acid, diluted 1:4, and injected in excess of 25 cm. Add 5 cmof phosphoric acid, 2cmof a solution with a mass fraction of 0.5% of silver nitrate, 2−3 g naternicola ammonium and dilute with water to 150 cm. The solution was boiled for 10 min to completely oxidize the manganese. The cooled solution is titrated with a 0.1 M solution of Mohr salt in the presence of 0.5 cmof solution with a mass fraction of 0.2% phenylanthranilic acid.

3.4. Processing of the results

3.4.1. Mass fraction of manganese () in percent is calculated by the formula

,

where  — the volume of salt solution Mora, used for titration of manganese, cm;

mass concentration of salt solution Mora, expressed in g/cmof manganese;

 — aliquota part of the analyzed solution, cm;

 — the weight of the portion,

3.4.2. The difference between the largest and smallest results of the three parallel measurements, and the two results of the analysis at a confidence level of 0.95 does not exceed the permissible differences given in table 2.

Table 2

3.4.1, 3.4.2. (Changed edition, Rev. N 2).