GOST R 52518-2006

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  ГОСТ Р 52518-2006

GOST R 52518−2006 Platinum. Method for determination of loss on heating

GOST R 52518−2006

Group B59

NATIONAL STANDARD OF THE RUSSIAN FEDERATION

Platinum

METHOD FOR DETERMINATION OF LOSS ON HEATING

Platinum. Method for determination of mass losses after ignition

OKS 39.060

Date of introduction 2006−07−01

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 State Agency for the formation of the State Fund of precious metals and precious stones of the Russian Federation, storage, holiday and use of precious metals and precious stones (Gokhran of Russia) under the Ministry of Finance of the Russian Federation, Moscow state Academy of fine chemical technology. M. V. Lomonosov (MITHT M. V. Lomonosov)

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 February, 6th, 2006 N 1-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 applies to affilirovannuju platinum powder with a mass fraction of platinum not less than 99.8%, designed for the production of alloys, semi-finished products, chemical compounds of platinum and other purposes.

The standard specifies a method of determining the weight loss during calcination of the powder of platinum in the range of mass fraction from 0% to 0.05%.

The method is based on determining the mass difference of the sample before and after calcination.

2 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 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 document is replaced (modified), then the use of this standard should be guided by the replaced (modified) document. If the reference document is cancelled without replacement, then the situation in which the given link applies to the extent that does not affect this link.

3 Terms and definitions

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

4 Accuracy (trueness and precision) of the method

4.1 indicators of the accuracy of the method

Indicators of accuracy of the method: the limit of absolute error of the results of the analysis (the boundaries of the interval in which the measurement error is determined with a probability of 0.95), the standard deviation of repeatability and intermediate precision, the values of the critical range of the limit of intermediate precision and reproducibility limit depending on the mass fraction of the element — impurities are listed in table 1.


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

Percentage

4.2 Correctness

Systematic error of the present method of analysis is not meaningful at all levels of the designated contents.

4.3 Precision

4.3.1 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 to 4 on average not more than once in 20 cases with proper use of the method.

4.3.2 within a single laboratory result 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.

4.3.3 the results of the analysis of the same samples, obtained in two laboratories in accordance with sections 6 and 7 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.

5 Requirements

5.1 General requirements and safety requirements

General requirements, requirements for security of works and environmental safety — according to the normative documents on the General requirements for methods of analysis of precious metals and their alloys.

5.2 qualifications of performers

In the analysis by this method is open to persons under the age of 18, trained in the prescribed manner and allowed to work independently.

6 of a measuring instrument and used assistive devices

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.

Desiccator, according to GOST 25336.

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

Crucibles porcelain N 3 according to GOST 9147.

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

7 analysis

7.1 Clean platinum crucible with constant mass is placed in a porcelain crucible and calcined in a furnace for 10−15 min at temperatures from 700 °C to 900 °C. after calcination porcelain crucible with a platinum crucible is removed from the oven, cooled in a desiccator to a temperature of (20±5)°C and determine the mass of the platinum crucible with an accuracy of 0,0001 g.

7.2 In the same platinum crucible weighed 5 g of the analyzed metal with accuracy up to 0,0001 g. the Crucible with metal and placed in a porcelain crucible and calcined in a furnace at temperatures from 700 °C to 900 °C for 20−25 min, remove the porcelain crucible with the platinum crucible from the furnace and cooled in a desiccator to a temperature of (20±5)°C.

7.3 a Platinum crucible with a charge of metal is weighed, placed in a porcelain crucible and calcined at temperatures from 700 °C to 900 °C for 10−15 min, then cooled in the desiccator to the temperature of (20±5)°C and re-weighed. The operation of calcination and cooling, the crucible is repeated until obtaining constant weight of the platinum crucible with metal.

7.4 the difference between the mass of the crucible with the metal before and after incineration gives the mass loss during annealing in the sample.

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

8.1 loss of mass on ignition (mass fraction) , %, is calculated by the formula

, (1)

where the difference in mass of the crucible with the platinum before and after ignition, g;

 — hanging platinum,

8.2 acceptance 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 range, where

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 , all the results and recognise acceptable 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 , spend four parallel determinations.

If the received eight parallel measurements, the value () does not exceed the critical range , 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.

9 precision Control

9.1 Control of 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 2.