GOST 22518.1-77

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  ГОСТ 22518.1-77

GOST 22518.1−77 Lead of high purity. Chemical-spectral method of determination of impurities (with Amendments No. 1, 2, 3)

GOST 22518.1−77

Group B59

STATE STANDARD OF THE USSR

LEAD OF HIGH PURITY

Chemical-spectral method of determination of impurities

Lead of high purity.
Chemical spectral method for the determination of additions

AXTU 1709

Date of introduction 1978−01−01

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of nonferrous metallurgy of the USSR

DEVELOPERS

HP Garcin, L. K. Larina

2. APPROVED AND promulgated by the Decree of the State Committee of standards of Ministerial Council of the USSR from 10.05.77 N 1170

3. INTRODUCED FOR THE FIRST TIME

4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

5. The expiration time limit is removed by the Resolution of Gosstandart from 08.04.92 377

6. The re-release (Dec 1996) Amendments No. 1, 2, 3, approved in January 1983, June 1987, April 1992 (IUS 5−83, 9−87, 7−92)


This standard specifies the chemical-spectral method of determining the mass fraction of bismuth, aluminum, cadmium, indium, zinc, sodium, iron, magnesium, silver, copper, calcium, antimony, arsenic, Nickel, lead of high purity grades S0000, S000, S00.

The method is based on obtaining a concentrate of impurities by separating the main mass of lead in the form of nitrate and spectral determination of impurities in the concentrate.

The method provides at 300-fold enrichment determination of the mass fraction of impurities in the lead in percents:

1. GENERAL REQUIREMENTS

1.1. General requirements for method of analysis according to GOST 22306.

1.1.1. Sampling — according to GOST 22861.

1.1.2. Numeric values of analysis results are rounded in expressing a number with the last digit of the same rank as that of the numeric value of the corresponding allowable differences.

1.1.3. Control of the correctness of the results of the analysis carried out according to GOST 22306 each time at replacement of a batch of samples comparison, in the repair of installations, after long interruptions and other changes that affect the result of the analysis.

Sec. 1. (Changed edition, Rev. N 3).

1a. SAFETY REQUIREMENTS

1A.1. In the analysis of lead in high purity in the laboratory of spectral analysis should be carried out on appliances and electrical installations, serially manufactured according to the specifications and drawings of the manufacturers, the relevant regulations for electrical installation, approved by Gosenergonadzor. Samples of lead submitted for analysis should be stored in plastic bags and reagents used for the analysis in the original packaging, in cupboards or boxes made of Plexiglas, equipped with a ventilation system.

1A.2. When used in electrical equipment and electrical installations in the process of spectral analysis must comply with the rules of technical operation of electrical installations and safety rules at operation of electrical installations, approved by Gosenergonadzor, and according to GOST 12.3.019. All appliances should be equipped with devices for grounding corresponding to GOST 12.2.007.0 and GOST 2.721. Grounding must conform to the rules of arrangement of electrical installations, approved by Gosenergonadzor.

(Changed edition, Rev. N 3).

1A.2.1. In the analysis of lead in high purity using the following reagents and materials which have a deleterious effect on the human body: lead, cadmium, indium, copper, antimony, arsenic, Nickel, mercury, thallium, ammonia, chloroform, carbon tetrachloride, ethyl alcohol, nitric, hydrochloric, sulphuric and acetic acids, carbon electrodes, when sharpening which is formed of carbonaceous dust. When working with these substances should observe the safety requirements contained in the normative-technical documentation on their production and application. When working with flammable and combustible substances should fulfil the requirements of GOST 12.1.004.

(Changed edition, Rev. N 2).

1a.2.2. When performing tests, it is necessary to observe the basic rules of safe work in chemical laboratories*.
________________
* On the territory of the Russian Federation the document is not valid. Acts PND f 12.13.1−03. — Note the manufacturer’s database.

1A.3. To prevent contact with the air, ozone, nitrogen oxides, metals and carbon, which are the sources of spectra excitation and bad acting on the body in quantities exceeding the maximum allowable concentration, each excitation source spectra must be located inside of the device, equipped with local exhaust ventilation.

1A.3.1. Each source of spectra excitation must have the metal casing for protection against electromagnetic radiation and burns by ultraviolet rays.

1A.3.2. The machine is used for grinding carbon electrodes must have a built-in pleasepray exhaust ventilation to prevent carbon dust in the air of working zone in quantities exceeding the maximum allowable concentration.

1A.3.3. Preparation of samples for analysis (the capture batches, dissolution, evaporation) has to carry out in boxes equipped with local exhaust ventilation.

1A.4. The content of harmful substances contained in item 1A.2.1, in the air of working zone shall not exceed the standards specified in GOST 12.1.005.

Analyses of air samples for the content of harmful substances in the air of working zone according to the technical specifications on methods of determination of harmful substances in the air, approved by the USSR Ministry of health, and the techniques developed in accordance with GOST 12.1.016.

(Changed edition, Rev. N 2).

1A.5. Samples of lead of high purity, the remainder of the analysis must return to the manufacturer (customer). With the aim of environmental protection, recycling, disposal and destruction of hazardous substances — waste from the production tests should be carried out in accordance with normative-technical documentation, agreed with the USSR Ministry of health.

1A.6. The premises of the laboratory of spectral analysis and their coverage must meet the SN 245−71 and SNiP II-4−79.

1A.6.1. The laboratory of spectral analysis must have a common supply and exhaust ventilation according to GOST 12.4.021.

1a.6.2. The laboratory should have fire extinguishers and boxes of sand according to GOST 12.4.009.

1a.6.3. In the analysis of lead high purity laboratory spectral analysis should be provided with special premises and devices in accordance with SNiP II-92−76 (group III and production processes).

1A.7. In the analysis of high purity lead all work must be performed in the dry the proper clothing, using protective equipment (rubber gloves, goggles, respirator), in accordance with GOST 12.4.011 and standard industry regulations of free issue of workwear, footwear and protective equipment to workers and employees of the enterprises of nonferrous metallurgy, as approved by the State Committee for labor and social Affairs. Clothing should be stored in racks separately from your own clothes, weekly, handing it to the Laundry. Not allowed to make clothing, and also reside in it outside of the working space.

1a.7.1. Working with lead should provide food products replacing milk, in accordance with the rules of free issue of milk or other equivalent food products to workers and employees in factories, workshops, stations and other departments with hazardous working conditions, approved by the State Committee for labor and social issues, which need to be taken before and after work.

1A.7.2. To work in the spectral laboratories should be open to persons trained in the basic techniques of working with instruments for electrical units and methods of analysis.

1A.7.3. Coming to work and working should be held: preliminary and periodic medical examinations, pre-training in the work with hazardous substances and the rules for the treatment of protective equipment; safety instructions with the corresponding record in the prescribed manner according to GOST 12.0.004.

Sec. 1a. (Added, Rev. N 1).

2. APPARATUS, MATERIALS AND REAGENTS

The quartz spectrograph medium dispersion type of ISP-28 or ISP-30 (complete set).

The spectrograph diffraction type IPS-8 or IPS-13 (complete installation).

A constant current source providing a voltage of 200−400 V and currents up to 16 A.

Microphotometer of any type, allowing to measure the density of the blackening of analytical lines.

Hot plate heating according to GOST 14919.

Muffle furnace with temperature up to 1000 °C.

Grinding machine carbon electrodes.

Analytical scale with a weighing error of no more than 0.0002 g and a torsion scales with a weighing error of no more than 0.001 g.

The stopwatches.

Caps glass.

Boxes of organic glass.

Volumetric flasks according to GOST 1770 with a capacity of 100; 200 cm.

Quartz flask with a capacity of 250 and 500 cm.

The quartz crucibles with a capacity of 50 and 100 cm.

Pipettes with a capacity of 1, 2, 5 and 10 cmaccording to GOST 29169.

Apparatus quartz distillation water and acids.

Stand for electrodes of organic glass.

Chrome-plated tweezers with tips made of PTFE.

Jars-plastic or plastic with lids with capacity of 50 and 100 cm.

Knife made of titanium or tantalum.

Electrodes, carbon, high purity having the following dimensions: the bottom — with a crater depth of 4 mm, a diameter of 4 mm and a wall thickness of 0.5 mm; upper diameter of 6 mm, a length of 30−50 mm, one end sharpened to a cone.

Graphite powder of high purity according to GOST 23463.

Nitric acid according to GOST 11125 (if necessary, double-distilled in quartz apparatus) and diluted 1:2.

Sulfuric acid according to GOST 14262 (distilled in quartz apparatus), diluted 1:1.

Tartaric acid according to GOST 5817, h.d. a.

Acetic acid according to GOST 18270, OS. h solution with a concentration of 30 g/DM.

Ammonia water according to GOST 3760, h.d. a.

Sodium chloride according to GOST 4233, H. h

The technical rectified ethyl alcohol according to GOST 18300.

Lead of high purity according to GOST 22861.

Distilled water according to GOST 6709, distilled in a quartz apparatus, the freshly prepared.

Lead sulfate; prepared as follows: 40 g of lead of high purity is dissolved in 150 cmof nitric acid, diluted 1:2, the precipitated lead sulfate by gradual addition of concentrated sulphuric acid. The solution is decanted from the precipitate and discarded. The precipitate is washed twice with 130 cmof water, acidified with nitric acid, dried and calcined in a muffle furnace at 550 °C. lead Sulphate is stored in a plastic jar.

The solution of nitrate of bismuth containing 1 mg of bismuth at 1 cm.

The solution of nitrate of aluminium, containing 1 mg of aluminium 1 cm.

A solution of cadmium nitrate containing 1 mg of cadmium in 1 cm.

India nitrate solution containing 1 mg India 1 cm.

A solution of zinc nitrate containing 1 mg of zinc 1 cm.

The solution of nitrate of iron, containing 1 mg of iron per 1 cm.

A solution of magnesium nitrate containing 1 mg per 1 cm.

A solution of silver nitrate containing 1 mg of silver in 1 cm.

A solution of copper nitrate containing 1 mg of copper in 1 cm.

The solution of nitrate of calcium, containing 1 mg of calcium in 1 cm.

The solution of nitrate of Nickel containing 1 mg of Nickel per 1 cm.

These solutions were prepared by dissolving calculated quantities of metals, their oxides, carbonate or nitrate salts in nitric acid. The resulting solutions are transferred to volumetric flasks, adjusted to the mark with water and mix. In solutions is not allowed the presence of chlorine ions.

The solution of nitrate of antimony, containing 1 mg of antimony 1 cm; prepared as follows: into a glass with a capacity of 50 cmis placed 200 mg of finely ground antimony GOST 1089 and poured 20 cmof concentrated nitric acid. The contents of the beaker heated in a water bath before the transfer of all of the antimony in measuremenu acid. Then, without stopping the heat, pour 10 cmof water and add 4 g of tartaric acid. The obtained clear solution is transferred to a volumetric flask with a capacity of 200 cm, adjusted to the mark with water and mix.

The arsenic solution containing 10 mg of arsenic to 1 cm; prepared by dissolving calculated quantity of the arsenious anhydride according to GOST 1973 in the water with a few drops of ammonia in low heat. The solution was transferred to a volumetric flask, adjusted to the mark with water and mix.

A sodium solution containing 1 mg of sodium per 1 cm; prepared by dissolving sample of sodium chloride in water. The solution was transferred to a volumetric flask, adjusted to the mark with water and mix.

Spectrographic plates of types I, II, S., UFS-3, slide and «pangram».

Developer metagitnionom.

Fixer is acidic.

Samples comparison.

Note. Allowed the use of devices with photovoltaic spectra and other spectral instruments, reagents, materials, and photographic plates, generating accuracy metrics that are regulated by this standard.

(Changed edition, Rev. N 1, 2, 3).

3. PREPARATION FOR ASSAY

3.1. The basis for the preparation of samples of comparison is sulphate of lead. To prepare a sample No. 1 (series 1) in a quartz Cup with a capacity of 200 cmplace of 43.9 g of sulfate of lead and introduce the standard solutions so that they do not touch the surface of the Cup. The solutions are injected alternately, after drying the previous batch. The volume of fluids and their mass concentrations are given in table.1.

The mixture is cautiously evaporated, dried, calcined in a muffle furnace at 550 °C for 1 h and triturated quartz pestle.

Table 1

The resulting sample contains in percent based on the lead:

Samples No. 2, 3 and 4 prepared by dilution of the sample N 1, 3, 10, 30 times lead sulfate used as the basis. Sample No. 5 is prepared by diluting a sample of N 4 three times.

Each of the prepared samples are mixed with graphite powder in a ratio of 5:1 (by weight). The samples of the comparison is stored in tightly sealed jars made of polyethylene. To the received set of samples of the comparison is attached in a separate jar a basis of sulphate of lead, mixed with powder graphite in a ratio of 5:1 (by weight), which serves as the zero sample. Mass fraction of impurities in the basis determined by supplements, for photographing the spectra recommended in this standard method, and introduce the amendment in the estimated mass fraction of impurities in the samples comparison.

A separate series of samples of the comparison serves to determine the mass fraction of arsenic. For the preparation of sample No. 1 in a quartz Cup place of 43.9 g of lead sulfate, moisten it with alcohol and injected 3 cmstandard solution containing 10 mg of arsenic in 1 cm. The mixture was dried, triturated and mixed. Sample N 1 contains 1·10% of arsenic per lead.

A series of working samples comparison with declining three times the mass fraction of arsenic receive serial dilution of each newly obtained sample with lead sulfate.

Prepared samples of the comparison is mixed with carbon powder in a ratio of 5:1 and stored in plastic jars with lids.

To determine the mass fraction of sodium in the lead is preparing a third number of samples comparisons on the same basis. For the preparation of the first sample is weighed in a quartz Cup of 43.9 g of lead sulfate, moisten it with alcohol and injected 3 cmstandard solution containing 1 mg of sodium per 1 cm. The mixture was dried, triturated and mixed. The resulting sample contains 1·10% of sodium based on the lead.

A series of working samples comparison with declining three times the mass fraction of sodium get a serial dilution of each newly obtained sample with lead sulfate. The resulting samples are stored in jars with lids.

Mass fraction of sodium in the basis of the additives was determined by photographing the spectra recommended in the standard methods, and introduce the amendment in the estimated mass fraction of impurities in the samples comparison.

(Changed edition, Rev. N 1, 2, 3).

4. ANALYSIS

4.1. Chemicals concentration of impurities

To analyze a sample of lead cut into pieces weighing 50−500 mg, take two sample weighing 40 grams and placed in flat-bottomed flasks with a capacity of 500 cm(bulb pre-made label 200 cm). Poured 30 cmof acetic acid. Intensively mixed, the acid is drained. The sample washed twice with water. Pour 150 cmof nitric acid, diluted 1:2, and the lead is dissolved by heating. The solution is heated to boiling, then pour 150 cmof boiling concentrated nitric acid. Acid is added in portions of 30 cmthree times, at 20 cmdouble 10 cmtwo times with vigorous stirring. In a precipitate of nitrate of lead. The contents of the flask evaporated to a volume of 200 cm, cooled in ice water for 1 h. the Solution was decanted to another flask (labeled 100 cm). The precipitate is washed twice with concentrated nitric acid in portions of about 15 cm, carefully mixing. After settling, the wash solution decanted into a flask containing the main solution. The solutions were evaporated to a volume of 100 cm, cool 20 min, then poured into a previously weighed quartz crucible. The precipitate is washed with 5 cmof concentrated nitric acid. Wash solution poured into the same crucible and evaporated to a volume of 5−10 cm. The walls of the crucible is washed with water, priliva it until complete dissolution of the precipitate. Add 1 cmof sulfuric acid diluted 1:1, evaporated, dried and calcined in a muffle furnace at 550 °C for 30 min.

Each concentrate is thoroughly mixed with powder graphite in a ratio of 5:1 (by weight).

In determining the sodium concentrates of samples and control experience with powder graphite don’t mix.

The enrichment coefficient () is calculated by the formula

,

where is the initial mass of sample, g;

 — mass of the concentrate obtained after ignition, g;

0,683 — stoichiometric ratio of lead sulfate to lead.

At the same time through the entire course of the analysis are controlling experience for inclusion in the analyses adjusted for purity of the reagents and the conditions of experience. For this into the conical flask pour all reagents required for the dissolution of lead, deposition and separation of nitrate (as the enrichment of samples). The contents of the flask is evaporated, poured into a quartz Cup, the wall of the flask is washed with water. The solution is evaporated to a volume of 5−10 cm. The walls of the Cup is washed with water. Add a Cup of 100−200 mg of lead sulfate, 1 cmof sulfuric acid diluted 1:1. Then the solution was evaporated to dryness, dried, calcined and the concentrate is mixed with powder graphite in a ratio of 5:1 (by weight).

The enrichment coefficient () in the reference experiment is calculated by the formula

,

where  — weight of lead, taken for analysis, g;

the weight of lead sulphate, is taken as the basis for the reference experiment,

Concentrates of samples and control experiences analyzed by the spectral method.

(Changed edition, Rev. N 1, 2).

4.2. Spectral analysis of the concentrate of impurities

References N 5, 4, 3, 2, 1 (series 1) and N 4, 3, 2, 1 (series 2), the concentrates of the samples and the reference experiment weighed 30 mg on a torsion scale (from each reference sample three sample, and from concentrates of samples and control experience on two hinges), placed in carbon electrodes craters depth and diameter of 4 mm and burned in the arc of DC power 13 A. Exhibit «to complete combustion of the sample» plus 10 C. the pre-fired Electrodes in the arc of direct current at 12−13 And in 10−15 s.

The spectra are photographed on the spectrograph ISP-28 or ISP-30. The width of the slit of a spectrograph of 0.010 mm. coverage of the two-slit. Using a quartz lens of 75 mm, which is set from the light source at a distance of 100 mm from the slit 316 mm in Front of the slit establish a three-step attenuator, which has a step with a transmittance of 30% cover black paper.

In the cassette placed three plates: type OFS-3 (for region 210−250 nm), type II and ES (for the area 250−390 nm) and slide or type I (region 390−440 nm).

Spectra of the samples and comparison samples are photographed on the same plate at least two times. On this same plate photographed range of lead through a nine-reliever for building a characteristic curve.

In determining the sodium spectra of samples comparison concentrates of samples and control experience photographing the spectrograph DFS-8 DFS or-13 with being light cracks through the filter ВС4.

Current of 13 A; the time of exposure to complete combustion of the sample and 10 s; the width of the slit of a spectrograph 0,015 mm.

The cassette is placed a photographic plate of the type «pangram».

(Changed edition, Rev. N 1, 3).

5. PROCESSING OF THE RESULTS

5.1. On microphotometer measure the blackening of analytical lines and background around each of these lines .

Photometric the following analytical lines (wavelength in nanometers):

According to the measured values , find the values of the logarithms of the intensity and . With the help of tables of logarithms find the values of the intensities , . The value of the intensity of the line () is calculated by the formula

.

Calibration graphs constructed in the coordinates , and find the content of impurities in the concentrates the sample () and reference experiment ().

The concentration of impurities determined in the sample is calculated by the formula

.

For the results analysis be the arithmetic mean of results of two parallel measurements obtained on the same photographic plate.

(Changed edition, Rev. N 1, 3).

5.2. Discrepancies in the results of parallel measurements () and the results of two tests () at a confidence probability of 0.95 should not exceed the values given in table.2.

Table 2

Permitted discrepancies for the intermediate mass fraction of impurities is calculated by the formula

for a mass fraction of 7·10% 1·10%:

,

for a mass fraction of more than 1·10%:

,

where is the arithmetic mean of the results of parallel measurements;

 — the average of the two results of the analysis.

(Changed edition, Rev. N 3).