GOST R 52950-2008

• gost-r-52950-2008.pdf (258.73 KiB)
  ГОСТ Р 52950-2008

GOST R 52950−2008 Palladium. Method for determination of loss on heating

GOST R 52950−2008

Group B59

NATIONAL STANDARD OF THE RUSSIAN FEDERATION

Palladium

METHOD FOR DETERMINATION OF LOSS ON HEATING

Palladium. Method for determination of mass loss after ignition

OKS 39.060
AXTU 1709

Date of introduction 2009−07−01

Preface

The objectives and principles of standardization in the Russian Federation established by the Federal law of 27 December 2002 N 184-FZ «On technical regulation», and rules for the application of national standards of the Russian Federation — GOST R 1.0−2004 «Standardization in the Russian Federation. The main provisions"

Data on standard

1 DEVELOPED by the Open joint-stock company «Krasnoyarsk factory of nonferrous metals named after V. N. Gulidova» (OJSC Krastsvetmet)

2 SUBMITTED by the Technical Committee for standardization TC 102 «Platinum metals"

3 APPROVED AND put INTO EFFECT by the Federal Agency for technical regulation and Metrology from August 14, 2008 N 174-St

4 INTRODUCED FOR THE FIRST TIME


Information about the changes to this standard is published in the annually issued reference index «National standards», and the text changes and amendments — in monthly indexes published information «National standards». In case of revision (replacement) or cancellation of this standard a notification will be published in a monthly information index «National standards». Relevant information, notification and lyrics are also posted in the information system of General use — on the official website of the Federal Agency for technical regulation and Metrology on the Internet

1 Scope

This standard covers refined palladium powder with a mass fraction of palladium is not less than 99.8%, designed for the production of alloys, semi-finished products, chemical compounds of palladium.

The standard specifies a method of determining the weight loss during calcination of the powder of palladium in the range of mass fraction from 0.002% to 0.050%.

2 the essence of the method

The method is based on calcination of the sample of refined palladium at a temperature from 850 °C to 950 °C to constant weight and determining the loss in mass (the mass difference of the sample before and after calcination) by gravimetric method.

3 Normative references

This standard uses the regulatory references to the following standards:

GOST R 8.563−96 State system for ensuring the uniformity of measurements. Methods of measurement

GOST R ISO 5725−1-2002 Accuracy (trueness and precision) of methods and measurement results. Part 1. General provisions and definitions

GOST R ISO 5725−6-2002 Accuracy (correctness and precision) of methods and measurement results. Part 6. The use of precision values in practice

GOST R 52599−2006 Precious metals and their alloys. General requirements for methods of analysis

GOST 6563−75 technical articles made of noble metals and alloys. Specifications

GOST 9147−80 Glassware and equipment lab porcelain. Specifications

GOST 24104−2001 laboratory Scales. General technical requirements

GOST 25336−82 Glassware and equipment laboratory glass. The types, basic parameters and dimensions

Note — When using this standard appropriate to test the effect of reference standards in the information system of General use — on the official website of the Federal Agency for technical regulation and Metrology on the Internet or published annually by the information sign «National standards» published as on January 1 of the current year and related information published monthly indexes published in the current year. If the reference standard is replaced (changed), when using this standard should be guided by replacing (amended) standard. If the reference standard is cancelled without replacement, then the situation in which the given link applies to the extent that does not affect this link.

4 Terms and definitions

This standard applies the terminology according to GOST R ISO 5725−1 and GOST R 8.563.

5 Accuracy (trueness and precision)

5.1 indicators of the accuracy of the method

Indicators of accuracy of the method: limit of the interval in which with a probability of 0.95 is the absolute error of the results of the analysis (assigned error) , standard deviation of repeatability and intermediate precision , the values of the critical range (4), the limit of intermediate precision and reproducibility limit , depending on the mass fraction of the mass loss on ignition in table 1.

Table 1 — Indicators of accuracy of the method (0,95)

Percentage

5.2 Correctness

Systematic error of the present method of analysis is not meaningful within the specified ranges of mass fraction loss during annealing.

5.3 Precision

5.3.1 Range of results four definitions obtained for the same sample by one operator using the same equipment within the shortest possible time intervals may be greater than indicated in the table 1 critical range (4) to 4 on average not more than once in 20 cases with proper use of the method.

5.3.2 within one laboratory two results of the analysis of the same sample obtained by different operators using the same equipment on different days, can vary in excess of the limit of intermediate precision specified in table 1, on average not more than once in 20 cases with proper use of the method.

5.3.3 Results of the analysis of the same samples, obtained in two laboratories in accordance with sections 7 and 8 of this standard may vary in excess of the limit of reproducibility according to GOST R ISO 5725−1 specified in table 1, on average not more than once in 20 cases with proper use of the method.

6 Requirements

6.1 General requirements and safety requirements

General requirements for method of analysis, the requirements for security of works and ensuring environmental safety is regulated in GOST R 52599.

6.2 qualifications of performers

To perform analysis allowed persons over the age of 18, trained in the prescribed manner and allowed to work independently on used equipment.

7 measurement Means, auxiliary devices, materials and reagents

Furnace with thermostatic control, ensuring the heating temperature up to 1000 °C.

Laboratory scales according to GOST 24104 with a limit of permissible absolute error no more than ±0,0001 g.

From Kipp apparatus for generating hydrogen.

Desiccator, according to GOST 25336.

Platinum crucibles N 100 N 101 covers according to GOST 6563.

Crucibles porcelain N 3 according to GOST 9147.

Watch for General use.

Allowed the use of other measuring instruments and auxiliary devices subject to receipt of the accuracy rate that rivals those in table 1.

8 analysis

8.1 Clean platinum crucible placed in a porcelain crucible and calcined in a furnace for 10−15 min at temperatures from 850 °C to 950 °C. after calcination porcelain crucible with a platinum crucible is removed from the oven, recover platinum crucible flame of hydrogen to obtain the gray surface of the crucible, cool in a desiccator to room temperature (15 °C to 30 °C) for 40 min, weighed with an error not more than ±0,0001 g.

The operation of the incineration, recovery, cooling and weighing the crucible is repeated until obtaining constant weight.

Criterion bring the crucible to constant weight is the difference of the results of successive weighings not exceeding 0,0001 g.

8.2 In the same platinum crucible, brought to a constant weight, is placed from 4.5 to 5.5 g of analyzed metal and weigh the crucible with the metal with the error not more than ±0,0001 g. the crucible with the metal is placed in a porcelain crucible and calcined in a furnace at temperatures from 850 °C to 950 °C for 40−45 minutes, then remove the porcelain crucible with the platinum crucible from the furnace, restore the analyzed metal in the crucible flame of hydrogen within 2−3 min, cool in the desiccator to room temperature from 15 °C to 30 °C for 40 min and weighed, determine the mass of the crucible with the charge of calcined metal.

The operation of the incineration, recovery, cooling and weighing the crucible with metal is repeated to obtain a constant weight by reducing the time of calcination to 10−15 min.

Criterion bringing the crucible with the metal to constant weight is the difference of the results of successive weighings not exceeding 0,0001 g.

9 Processing of results, evaluation of their acceptability and the achievement of a final result of the analysis

9.1 mass-Loss on ignition (mass fraction) , %, is calculated by the formula

, (1)

where is the difference of the mass of the platinum crucible with a suspension of palladium before and after calcination and recovery, g;

 — linkage of palladium,

The result of the analysis take the average of results of four parallel measurements calculated to the fourth decimal place and rounded to the third decimal place.

9.2 the acceptability of the results of parallel measurements was evaluated in accordance with GOST R ISO 5725−6 by matching range, results () with the critical range . The critical range is calculated by the formula

, (2)

where  — the ratio of the critical band;

is the number of parallel definitions;

 — standard deviation of repeatability.

Values and shown in tables 1 and 2, respectively.

Table 2 — Coefficients of the critical range

If the range of the results of four parallel samples () does not exceed the critical range (4), all results recognize acceptable and for the final result of the analysis take the average of results of four parallel measurements.

If the range of the results of four parallel measurements exceeds (4), conduct four parallel determinations.

If the received eight parallel measurements, the value () does not exceed the critical range (8), as a final result of the analysis taking the arithmetic mean of results of eight parallel measurements. Otherwise, as a final result of the analysis taking the median of the results of eight parallel measurements.

10 Control precision (intermediate precision and reproducibility)

When monitoring intermediate precision (variable factors of the operator and time) is the absolute difference of the two results of the analysis of the same sample obtained by different operators using the same equipment on different days, should not exceed the limit of intermediate precision specified in table 1.

Under the control of the reproducibility of the absolute disparity of the two results of the analysis of the same samples, obtained in two laboratories, in accordance with the requirements of this standard must not exceed the limit of reproducibility shown in table 1.