GOST 26252-84

• gost-26252-84.pdf (0.98 MiB)
  ГОСТ 26252-84

GOST 26252−84 niobium Powder. Specifications (with Change No. 1)

GOST 26252−84

Group 56

STATE STANDARD OF THE USSR

NIOBIUM POWDER

Specifications

Niobium powder. Specifications

GST 17 9531

Valid from 01.01.86
before 01.01.92*
_______________________________
* Expiration removed
Protocol N 3−93 Interstate Council
for standardization, Metrology and certification
(IUS No. 5/6, 1993). — Note the manufacturer’s database.

INFORMATION DATA

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

DEVELOPERS

A. V. Elyutin, E. N. Chukal, V. M. Mikhailov, N. With. Vorobiev, V. A., Agapov, 3.X.Yamaltdinova

2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from 06.08.84 N 2753

3. INTRODUCED FOR THE FIRST TIME

4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

5. Validity extended till 01.01.92 by the Resolution of Gosstandart of the USSR from 29.06.88 N 2549

6. REPRINT (December 1989) with amendment No. 1, approved in June 1988 (IUS 11−88)


This standard applies to niobium powder for capacitor production, alloying agent and for other purposes.

(Changed edition, Rev. N 1).

1. TECHNICAL REQUIREMENTS

1.1. Niobium powder shall be manufactured in accordance with the requirements of this standard in accordance with technical documentation approved in the established order.

1.2. Niobium powder is divided by chemical composition — brands of the NBP-a and NBP-b and NBP; granulometric composition — I, II, III and IV classes.

Symbol powder, OKP codes are given in the table.1.

Table 1

1.3. The chemical composition of niobium powder shall conform to the standards given in table.2.

Table 2

Extension table 2

Notes:

1. Mass fraction of impurities of Nickel, aluminum, magnesium, manganese, cobalt, tin, copper, zirconium is provided by the technology.

2. For powder class III mass fraction of oxygen must be not more than 0.3%.

1.4. The grain size deviation on the particle size and specific surface area niobium powder shall conform to the standards given in table.3.

Table 3

Notes:

1. Mass fraction fraction +100 µm for powders all classes should be not more than 0.5%.

2. On demand of the consumer is allowed to produce niobium powder 1st class with the allowable deviations in the size of the powder was 8%.

1.2−1.4. (Changed edition, Rev. N 1).

1.5. Particle size and shape for all classes of powder — fragmentation.

2. SAFETY REQUIREMENTS

2.1. Niobium powder in aerial environment and waste waters do not form toxic compounds.

2.2. Niobium powder has on the human body toxic fibrogenic action.

2.3. Niobium powder belongs to the class of inflammable combustible materials according to GOST 12.1.044−89.

The lower concentration limit of Flammability of aerospace niobium powder ncpv equal to 308 g/m.

Temperature Flammability aerospace — 520 °C.

In the absence of close, open flames or other heat sources capable of heating the niobium powder to a temperature higher than 500 °C, the niobium powder is fireproof.

2.4. To extinguish a niobium powder used asbestos cloth, argon. The most effective means of extinguishing a niobium powder is sodium chloride (table salt).

2.5. Work with niobium powder must be made in the overalls with the use of personal protective equipment:

rubber gloves;

glasses type SN, ZN according to GOST 12.4.013−85*;
______________
* On the territory of the Russian Federation GOST R 12.4.230.1−2007. — Note the manufacturer’s database.

respirator SB-1 brand «Petal» according to GOST 12.4.034−85*.
______________
* On the territory of the Russian Federation GOST 12.4.034−2001. — Note the manufacturer’s database.

3. ACCEPTANCE RULES

3.1. Niobium powder was taken by the parties. The party must consist of a powder of the same class, uniform in its chemical composition accompanied by a document about quality that contains:

trademark or name of the manufacturer and trademark;

product name and code for GST;

batch number;

number of seats in the party, if more than one;

the net weight of the batch;

the results of the tests;

the date of manufacture;

stamp of technical control Department;

the designation of this standard.

The weight of the batch shall be not less than 100 kg. According to the agreement with the consumer allowed the weight of the batch is less than 100 kg.

3.2. To control the quality of powder with the requirements of this standard, the manufacturer selects a sample weight of 3% by weight of the party. Control of mass fraction of Nickel, aluminum, magnesium, manganese, cobalt, tin, copper and zirconium is carried out once a quarter.

3.1; 3.2. (Changed edition, Rev. N 1).

3.3. Control the quality of powder with the requirements of this standard consumer spends on a sample weighing 300 g, which is part of the sample selected by the manufacturer according to claim 3.2 and included in the weight of the batch.

3.4. If unsatisfactory results of the analysis of at least one of the indicators of repeat analysis on a doubled sample taken from the same batch.

The results of the reanalysis are final and apply to the entire party.

(Changed edition, Rev. N 1).

4. METHODS OF ANALYSIS

4.1. Sampling

4.1.1. Spot samples are taken bailing on a square grid to the full depth of the layer of product. Spot samples are combined.

The resulting merged sample kvantovanie the reduce to an average sample weight of not more than 1200 g.

An average sample is divided into four parts: one part with a mass of 350 g, the second — 50 g — 400 g, fourth — 300 g

4.1.2. Each part of the sample Packed into the package made of polyethylene film GOST 10354−82, who put in a glass jar with a glass stopper or a glass or plastic jar with a screw cap. Packages sealed or knotted.

Allowed to pack the sample in a double plastic bag.

For each can of paste or between the package and the glass jar (or layer package) put a label containing:

the designation of this standard;

product name or its symbol and code-OKP;

class of powder;

the date of sampling;

batch number;

stamp of technical control Department.

4.1.3. A sample mass of 350 g is intended for determining the granulometric composition of the powder and the measurement of specific surface area.

A sample of 50 g is intended to control a mass fraction of impurities according to claim 1.3.

A sample weight of 400 g are stored with the manufacturer within one year in case of disagreement in assessing the quality of the powder.

A sample mass of 300 g is sent to the consumer for quality control of powder and included in the net weight.

4.2. Spectral method for the determination of Nickel, aluminum, magnesium, manganese, cobalt, tin, copper and zirconium in niobium

The spectral method is preceded by the transfer of the sample into the niobium pentoxide.

The method is based on measuring the intensity of the lines of the elements of the impurities in the spectrum obtained by evaporation of niobium pentoxide in the mixture with graphite powder and sodium chloride from the channel of the graphite electrode in the arc DC.

Mass fraction of impurities in niobium (table.4) is determined by calibration graphs constructed in the coordinates: logarithm of ratio of intensity of lines of the designated element and the background intensity is the logarithm of the concentration of a specific element .

Table 4

4.2.1. Apparatus, materials and reagents

The diffraction type spectrograph DFS-13 with grating of 600 and 1200 lines/mm and being light slit or similar device (photovoltaic device of the type MFS). You may use a spectrograph DFS-8 with grating of 1,800 lines.

The arc generator type DG-2 with optional rheostat or generator of the same type.

Rectifier 250−300, 30−50 A.

Microphotometer geregistreerde type MF-2 or similar type.

Spectromancer of PS-18, SP-2 or similar type.

Analytical scale.

Libra torsion bar type W-500.

Mortar and pestle made of organic glass.

Box of organic glass.

Muffle furnace with thermostat for temperatures up to 900 °C.

Cup platinum.

Grinding machine graphite electrodes.

The electrodes are graphite, machined graphite rods OS. H 7−3 6 mm in diameter, sharpened to a truncated cone with ground diameter of 1.5 mm.

The electrodes are graphite, machined graphite rods OS. H 7−3 with a diameter of 6 mm, with a channel depth of 5 mm, external diameter 3.0 mm, inner diameter is 2.0 mm, the length of the sharpened part is 6 mm.

Powder graphite OS. H 8−4 GOST 23463−79.

Photographic plates spectrographic brands SP-s and SP-2, size 9x12/or 13x18 1,2/1,2 for normal blackening of analytical lines and the surrounding background in the spectrum.

Lamp infrared ikz-500 with the voltage regulator RNO-250−0,5 or similar.

Rectified ethyl alcohol GOST 18300−87, double-distilled in quartz apparatus.

Nickel oxide black GOST 4331−78, CH.

Aluminum oxide, anhydrous, for spectral analysis, H. h

Magnesium oxide according to GOST 4526−75, h.d. a.

Manganese (IV) oxide according to GOST 4470−79, h.d. a.

Cobalt (II, III) oxide according to GOST 4467−79, h or h.d. a.

Tin dioxide, C. D. and.

Zirconium dioxide according to GOST 21907−76.

Copper (II) oxide under GOST 16539−79.

Sodium chloride OS. H 6−1.

Of niobium pentoxide in which the contents of the determined elements do not exceed established method for the lower boundary of the range of detectable concentrations.

Developer:

Fixer:

4.2.2. Preparation of the buffer mixture

A buffer mixture consisting of 90% carbon powder and 10% sodium chloride prepared by mixing to 0.9000 g of carbon powder and 0,1000 g of sodium chloride with 20 cmof ethanol for 30 min and drying under a heat lamp.

4.2.3. Sample preparation comparison (OS)

The main reference sample containing 1% of Nickel, aluminum, magnesium, manganese, cobalt, tin, zirconium and copper, prepared by mechanical abrasion and mixing buffer mixes with the oxides of the respective metals.

Hitch weight 0,0141 g of an oxide of Nickel, 0,0189 g of aluminium oxide, 0,0186 g of magnesium oxide, 0,0158 g of manganese oxide (IV) 0,0136 g (II-III) cobalt oxide, 0,0127 g of tin dioxide, 0.0125 g of copper oxide and 0,0140 g of zirconium dioxide was placed in a mortar made of organic glass and add 0,8818 g buffer mixture. Stir the mixture thoroughly, adding alcohol to maintain a mixture in pasty state, during 1 h and dried under an infrared lamp to constant weight.

Serial dilution of the primary reference sample, a buffer mixture is prepared a series of samples comparison of (OS) with decreasing concentration of the determined elements. The content of each of the designated impurities (in percent metal content in the metallic niobium) and added to the mixture of the sample buffer mixture and the diluted sample are given in table.5.

Table 5

The comparison samples stored in plastic jars with lids.

4.1.2 to 4.2.3. (Changed edition, Rev. N 1).

4.2.4. Analysis

4.2.4.1. Translation of niobium metal in the niobium pentoxide

A sample of niobium metal 1−3 g was placed in a platinum Cup and calcined in a muffle furnace at a temperature of 800−900 °C for 2 h. the Obtained niobium pentoxide in the form of a white powder was cooled in the desiccator, placed in a package of tracing paper and transferred to a spectral analysis.

4.2.4.2. The determination of Nickel, aluminum, magnesium, manganese, cobalt, tin, copper and zirconium

Samples of comparison is prepared in Boxing. For this, 100 mg of sample and 100 mg of buffer mix or 100 mg of reference sample and 100 mg of niobium pentoxide in a Styrofoam triturated in a mortar for 5 min. Prepared sample or comparison sample was Packed into the channels of the three graphite electrodes, prebaked in the arc of direct current at 7 A within 5 s.

The electrodes are installed in the tripod in a vertical position. The upper electrode is a graphite rod, sharpened to a cone. Between the electrodes ignite the arc DC power 7 And with the subsequent increase (20 C) up to 15 A. the Electrode with the sample included anode.

In order to avoid release of material from the crater of the electrodes, the current include with the serried electrodes with their subsequent breeding, the value of which is controlled by the projection on the intermediate diaphragm. Exposure time — 120 s, intermediate diaphragm — 5 mm.

Spectra in the region of wavelengths of 2500−3500 nm photographed with a spectrograph DFS-13 with grating of 600 lines/mm using being lighting system of the slit on a photographic plate type II CHUV. 15, the width of the slit of a spectrograph 15 microns.

4.2.4.3. Determination of copper

A sample prepared according to claim 4.2.4.2, is placed in the channel of the graphite electrode. The electrode and sample or reference sample is an anode (lower electrode). The upper electrode is a graphite electrode, sharpened to a cone. Between the electrodes ignite the arc DC. In the first 15 the current is 5 A, the subsequent 1 min 45 s — 15 A. Complete exposure of 120 s. the Spectra are photographed on a spectrograph DFS-13 with a grating 1200 lines/mm being the lighting system. The photographic plate of the type ES CHUV. 9. Intermediate diaphragm of 0.8 mm. Scale wavelengths set at 320 nm. The width of the slit of a spectrograph 15 microns. During exposure the distance between the electrodes is maintained at 3 mm.

The spectrum of each sample and each reference sample recorded on the plate three times. Exposed plates show washed with water, fixed, washed and finally dried.

4.2.4.1−4.2.4.3. (Changed edition, Rev. N 1).

4.2.4.4. Processing of the results

In each spectrogram photometric blackening of analytical lines of the designated element (table.6) and nearby background and calculate the difference of pochernenija .

Table 6

Three parallel values , , obtained three spectrograms taken for each sample, find the arithmetic mean of the results .

From the obtained average values are transferred to the values using the tables contained in the Annex to GOST 13637.1−77*.
______________
* On the territory of the Russian Federation GOST 13637.1−93, here and hereafter. — Note the manufacturer’s database.

Using the values and for samples comparison, build a calibration curve in the coordinates , . On this chart, values for samples determine the content of impurities in the sample.

The difference between the largest and smallest results of the three parallel and the results of two tests with a confidence level of 0.95 does not exceed the values of permissible differences given in table.7.

Table 7

Permitted discrepancies for the intermediate grades are calculated by using linear interpolation.

4.2.4.5. Control the correctness of the results

The correctness of the results of the analysis of a series of control samples for each specific admixture at the transition to the new set of samples comparison. For this purpose the same samples containing the impurity in a controlled range of concentrations with the use of old and new sets of samples comparisons are given four test results and calculate average arithmetic value. Then find the difference between larger and smaller values. The results of the analysis are considered correct if the difference does not exceed the permissible discrepancy of results of two analyses of samples on the content of the designated impurities.

Control over the correct conduct for each interval between the neighbouring content references on a rolling basis for analysis of appropriate samples.

4.3. The mass percent of tantalum, titanium, silicon, iron, tungsten, molybdenum determined according to GOST 18385.1−79-GOST 18385.4−79 or spectral methods (PP.4.3.1−4.3.3), oxygen and hydrogen — GOST 22720.1−77, nitrogen — GOST 22720.1−77 or GOST 22720.4−77.

Allowed to apply other methods of analysis of impurities, accuracy is not inferior to those specified.

The differences in the evaluation of the chemical composition of it is determined according to GOST 18385.1−79-GOST 18385.4−79, GOST 22720.1−77, GOST 22720.1−77 and GOST 22720.4−77.

Mass fraction of carbon is determined according to GOST 22720.3−77. In addition to the analyzer an-160 allowed to use devices an-7529 and an-7560.

4.2.4.4.-4.3. (Changed edition, Rev. N 1).

4.3.1. Spectral method of determination of impurities of titanium, silicon, iron, Nickel, aluminum, magnesium, manganese, tin, copper, zirconium, for the mass concentration of each impurity from 0.001 to 0.02.

The method is based on excitation of the arc DC and photographic registration of spectra and comparison of spectra of the analyte converted into the oxides by calcination, followed by determination of the mass fraction of impurities in the calibration graphs built in coordinates: log of the ratio of intensity of lines of the designated element to the background intensity is the logarithm of the mass fraction of the element .

The relative standard deviation characterizing the convergence of the results of parallel measurements, for the mass concentration of each impurity of 0.001% is 0.15, while the mass fraction of each impurity a 0.02% 0,11.

The total error of the analysis result with confidence probability of 0.95 in mass fraction of impurities 0,00100% shall not exceed ±0,00023% abs, when the mass fraction of impurities 0,0200% — ±0,0033% abs.

4.3.1.1. Apparatus, materials and reagents

The spectrograph DFS-13 with a grating 1200 lines/mm or similar.

A constant current source of UGE or-275−100, or similar.

Microdensitometer MD-100, or microphotometer MF-2, or similar.

Spectromancer type SS-18, or DSP-2, or similar.

Analytical scale with a weighing error of no more than 0,0002 g.

Libra torsion W-500 or similar with a weighing error of no more than 0,002 g.

Muffle furnace with thermostat, at a temperature from 400 to 1100 °C.

The drying oven of the type SPLM 3.5.3.5.3.5./3M or similar.

Grinding machine graphite electrodes.

Mortars and pestles made of Plexiglas.

Cup platinum according to GOST 6563−75.

Spectral photographic plates: slide, SP-2, SP-ES, providing in terms of analysis of normal blackening of analytical lines and the surrounding background in the spectrum.

Powder graphite OS.h. 8−4 according to GOST 23463−79 or similar to ensure cleanliness of the designated impurities.

The lower electrodes machined from graphite rods by the OS.h. 7−3 with a diameter of 6 mm, having dimensions, mm:

The upper electrodes of graphite rods OS.h. 7−3 6 mm in diameter, sharpened to a truncated cone with ground diameter of 1.5 mm and a height of the sharpened conical portion 4 mm.

Sodium fluoride, OS.h. 7−3.

Of niobium pentoxide for optical glass manufacturing, OS.h. 7−3.

Titanium (IV) dioxide, OS.h. 7−3.

Silicon (IV) dioxide according to GOST 9428−73, h.d. a.

Iron (III) oxide, OS.h. 2−4.

Nickel (II) oxide, h.d. a.

Aluminium (III) oxide, H. h

Magnesium (II), h.d. a.

Manganese (IV) oxide, OS.h. 9−2.

Tin (IV) oxide, h.d. a.

Copper (II) oxide (granulated) GOST 16539−79.

Zirconium (IV) dioxide, OS.h. 6−2.

Rectified ethyl alcohol GOST 18300−87.

Lacquer ideology, 1% alcoholic solution.

Metol according to GOST 25664−83.

Hydroquinone according to GOST 19627−74.

Sodium sanitarily (sulfite) according to GOST 195−77.

Sodium carbonate according to GOST 83−79.

Potassium bromide according to GOST 4160−74.

Sodium thiosulfate crystal according to GOST 244−76.

Potassium sanitarily Piro (sodium metabisulphite).

Distilled water GOST 6709−72.

The developer is prepared as follows: 2 g of metol, 52 g of sodium sulfite, 10 g of hydroquinone, 40 g of sodium carbonate, 5 g of potassium bromide dissolved in water, in sequence to bring the volume of solution with water to 1000 cm, mixed and filtered.

Fixer, is prepared as follows: 250 g of sodium thiosulfate and 25 g of potassium metabisulfite is dissolved in the specified sequence in the 750−800 cmof water, bring the solution volume with water to 1000 cm, mixed and filtered.

Allowed to use developer and fixer recommended for used photographic plates.

The basic mixture is a mechanical mixture of niobium oxide and oxides of the identified elements with a mass fraction of each impurity of 1% based on the metal content of a mixture of metals. To prepare each drug oxide is placed in a separate Cup, calcined for 90 min in a muffle furnace at temperatures listed in table.7, cooled in a desiccator and take the sample given in table.7a. Transfer to a mortar first, approximately one-fourth of the sample of niobium pentoxide and then fully weighed portion of oxides of all elements-impurities and thoroughly RUB the mixture in a mortar for 60 min, adding alcohol to maintain a mixture in pasty condition. Then in the same mortar and carry the remaining part of the sample of niobium pentoxide and again triturated the mixture for 60 minutes, adding the alcohol to maintain the mixture in pasty condition. Thereafter, the mixture was dried in a drying Cabinet and then calcined at a temperature of (400±20) °C for 60 min and cooled in a desiccator.

Intermediate mixture and working samples comparison (РОС1-РОС4); prepared by mixing the indicated in table.7b weight of niobium pentoxide, the basic mixture, the intermediate mixture and a working sample comparison РОС2. Before taking batches of niobium pentoxide calcined for 90 minutes at (950±20) °C, and the OS, PS and РОС2 — temperature (400±20) °C for 60 min and cooled in a desiccator. Mixed by thorough grinding in a mortar for 60 min, adding alcohol to maintain a mixture in pasty condition. Thereafter, the mixture was dried in an oven, calcined at a temperature of (400±20) °C for 60 min and cooled in a desiccator.

Buffer a mixture of 95% graphite powder and 5% of sodium fluoride. The sample is placed in a mortar and triturated for 30 min.

4.3.1.2. Analysis

A portion of the powder of niobium metal with a mass of 0.5 g was placed in a platinum Cup, calcined in a muffle furnace at a temperature of 800−850 °C for 2 h and cooled in a desiccator. Transfer to a mortar and mixed with the buffer mixture in the ratio 2:1 (by weight) was placed in a package of tracing paper.

Each of the working samples comparison РОС1-РОС4 is also mixed with the buffer mixture in the ratio 2:1 (by weight).

The upper and lower electrodes are fired in the arc AC at a current of 10 A for 10 s.

Each of the resulting mixtures (a mixture obtained from a sample of samples, and obtained from РОС1-РОС4) densely fill the craters of the six lower electrodes by repeated immersion of the electrodes in a package with the mixture. After that, each lower electrode is placed 2 drops of the alcoholic solution infolavoro varnish. The electrodes are dried in a drying Cabinet at a temperature of 80−90 °C for (15±1) min.

In the cassette of the spectrograph is placed:

in the shortwave region of the spectrum — slide photographic plate;

in the long-wave — plate brand SP-2.

The lower electrode (the sample material or with a material working reference) include anode of a DC arc. The spectra photographed under the following conditions:

Photographed three times each working range of the reference sample and three times the spectrum of each sample, using for each reference sample (or samples) three of the six bottom electrodes. Then the photographing of the spectra was repeated, using the remaining three filled breakdown (the reference) of the lower electrode.

Exposed photographic plates show washed with water, fixed, and finally washed with water and dried.

4.3.1.3. Processing of the results

Each photographic plate photometric blackening of analytical lines of the designated element (table.7b) and the surrounding background and calculate the difference of pochernenija .

On three values , , derived from three spectrograms taken for each sample on one plate, find the arithmetic mean . From the received values are transferred to the values using the tables given in GOST 13637.1−77.

Table 7a

Using the values of (where  — mass fraction determined by the impurities at the table.7b) and obtained the first photographic plate values for work samples comparison РОС1-РОС4, build a calibration curve in the coordinates , . On this schedule, using the received on the same photographic plate the value for the sample, determine the mass percent of impurities in the sample — first two results of parallel measurements of the impurity.

Table 7b

Table 7b

The result of the second parallel determination get in the same way on the second plate.

The difference between the greater and lesser results of parallel measurements with a confidence probability of 0.95 does not exceed the allowable differences specified in table.7G.

Table 7G

Permissible variation for intermediate values of the mass fraction of impurities not specified in the table, find by linear interpolation.

If this standard is met, calculate the result of the analysis is the arithmetic mean of the results of two parallel measurements.

4.3.1.4. Control the correctness of the results — p. 4.2.4.5.

4.3.2. Spectral method of determination of impurities of tungsten, molybdenum and cobalt when the mass fraction of each impurity from 0.001 to 0.01%

The method is based on excitation of the arc DC and photographic registration of spectra and comparison of the analyte converted into the oxides by calcination, followed by determination of the mass fraction of impurities in the calibration graphs.

The relative standard deviation characterizing the convergence of the results of parallel measurements of each impurity, is 0,17 — when the mass fraction of the impurities and 0.10 — for the mass concentration of impurities 0,005−0,010%.

4.3.2.1. Apparatus, materials and reagents

The spectrograph DFS-13 — with the grating 600 gr/mm or similar.

A constant current source YOU-275−100 or similar.

Microphotometer MF-2 or similar.

Spectromancer DSP-2 or similar.

The drying oven of the type SPLM 3.5.3.5.3.5/3 M or equivalent.

Analytical scale with a weighing error of no more than 0,0002 g.

Libra torsion W-500 or similar.

Muffle furnace with thermostat for temperatures from 400 to 1000 °C.

Electric with a closed helix and coating, excluding pollution-defined elements.

Grinding machine graphite electrodes.

Mortars and pestles made of Plexiglas.

Cup platinum according to GOST 6563−75.

Desiccators.

Photographic plates format 9x12 cm spectral type II, and ES or similar, providing in terms of analysis of normal blackening of analytical lines and the background in the spectrum.

The bottom electrodes of the type «glass», machined from graphite rods by the OS.h. 7−3 with a diameter of 6 mm, having dimensions, mm:

The upper electrodes are rods with a diameter of 6 mm graphite OS.h. 7−3, sharpened cylinder with a diameter of 4 mm.

Hydrochloric acid according to GOST 14261−77, OS.h.

Of niobium pentoxide, OS.h. 7−3, in which the spectrum in terms of analysis there is no analytical lines of the designated impurities.

Tungsten (VI) oxide, h.d. a.

Molybdenum (IV) oxide, h.d. a.

Cobalt (II, III) oxide according to GOST 4467−79.

Antimony (III) oxide, H. h

The lead chloride.

Potassium sulphate, OS.h. 6−4.

Rectified ethyl alcohol GOST 18300−87.

Metol according to GOST 25664−83.

Hydroquinone according to GOST 5644−75.

Sodium sanitarily (sulfite) according to GOST 195−77.

Potassium bromide according to GOST 4160−74, h.d. a.

Sodium carbonate according to GOST 83−79, h.d. a.

Sodium thiosulfate crystal according to GOST 244−76.

Potassium sanitarily Piro (sodium metabisulphite).

Distilled water GOST 6709−72.

Chemical resistant glassware: beakers capacity 100, 500 and 1000 cm, funnel.

The developer is prepared as follows: 2 g of metol, 52 g of sodium sulfite, 10 g of hydroquinone, 40 g of sodium carbonate, 5 g of potassium bromide dissolved in water in the specified sequence, the volume was adjusted solution with water to 1000 cm, mixed and filtered.

Fixer, is prepared as follows: 250 g of sodium thiosulfate and 25 g of potassium metabisulfite is dissolved in the specified sequence in the 750−800 cmof water, bring the solution volume with water to 1000 cm, mixed and filtered.

Allowed to use developer and fixer recommended for used photographic plates.

The buffer mixture is prepared as follows: thoroughly ground in a mortar 7,4900 g of chloride of lead, 2,5000 g of potassium sulfate, 0,0100 g of antimony oxide. The time of abrasion on fibroidsmiracle 40−50 min, manually — 90−120 min.

The basic mixture is a mechanical mixture of the oxides of niobium and identify the impurities with a mass fraction of each impurity of 1% based on the metal content of a mixture of metals. For mixing each drug oxide is placed in a separate Cup, calcined for 90 min in a muffle furnace at temperatures listed in table.7D, cooled in a desiccator and take the sample given in table.7D. Transfer to a mortar of approximately the first part of the sample of niobium pentoxide and then fully weighed portion of oxides of all impurities and thoroughly RUB the mixture in a mortar for 60 min, adding alcohol to maintain a mixture in pasty condition. Then in the same mortar and carry the remaining part of the sample of niobium pentoxide and again triturated the mixture for 60 minutes, adding the alcohol to maintain the mixture in pasty condition. Thereafter, the mixture was dried in an oven, and then calcined at a temperature of (400±20) °C for 60 min and cooled in a desiccator.

Intermediate mixture and working samples comparison (РОС1-РОС4) is prepared by mixing the indicated in table.7E sample of niobium pentoxide, the basic mixture, the intermediate mixture and a working sample comparison РОС1. Before taking batches of niobium pentoxide calcined for 90 minutes at (950±20) °C, and the OS, PS and РОС1 — temperature (400±20) °C for 60 min; cool in a desiccator. Mixed by thorough grinding in a mortar for 90 min, adding alcohol to maintain a mixture in pasty condition. Thereafter, the mixture was dried in an oven, calcined at a temperature of (400±20) °C for 60 min and cooled in a desiccator. Alcohol added at the rate of 1 cmby 1 OS.

4.3.2.2. Analysis

A portion of the niobium powder with a mass of 0.5−0.6 g was placed in a beaker with a capacity of 100 cm, pour diluted 1:1 hydrochloric acid (30 cm) and kept on a hotplate until boiling. Thereafter, the acid is drained, the powder washed with distilled water, 3 cmalcohol, dried and calcined in a muffle furnace at 800 °C to complete oxidation. Cooled, transferred to a mortar, mixed with the buffer mixture in the ratio 3:1 (by weight) and placed in a package of tracing paper.

The resulting mixture was placed in the lower six electrodes (without weighing), filling the crater completely and removing the mixture from the ends of the electrodes are repeated immersion of the electrode in the bag with the mixture.

Each of the working samples comparison РОС1-РОС4 is also mixed with the buffer mixture in the ratio 3:1 (by weight) and placed in the lower six electrodes, filling the crater completely and removing the mixture from the ends of the electrodes.

Photographing the spectra produced in the following conditions:

On one photographic plate photograph of three samples of the spectrum, and the spectrum of each of the working samples in the comparison. Get two plates. Exposed photographic plates show washed with water, fixed, washed with water and dried.

4.3.2.3. Processing of the results

In each of the three spectra of the sample (sample or reference) taken on one photographic plate, photoretrieval find the blackening of analytical lines of the designated element (see table.7G), black line comparison of antimony Sb 323,25 nm and blackening of the background near the analytical line of tungsten W 400,87 nm.

Table 7D

In the determination of tungsten for each of the three spectra (samples or specimen for comparison) I find the value and calculate the arithmetic mean of the three values  — the value . According to the obtained average values to find the value using the tables according to GOST 13637−77. Using the values of (where  — mass fraction of tungsten at the table.7E) and obtained the first photographic plate values for work samples comparison РОС1-РОС4, build a calibration curve in the coordinates , . On this schedule, using the received on the same photographic plate values for the sample, determine the mass fraction of tungsten in the sample — the first of two results of parallel measurements. The result of the second parallel determination of tungsten is obtained in the same way on the second photographic plate.

In the determination of molybdenum and cobalt for each of the three spectra (samples or specimen for comparison) taken on the same photographic plate, find the value and calculate the arithmetic mean of the three values — the value . According to the obtained average values for samples comparison, build a calibration curve in the coordinates , where is the mass fraction of the element in samples of comparison according to table.7. On this schedule, using the received on the same photographic plate values for the sample, determine the mass fraction of the element in the sample — the first of two results of parallel measurements. The result of the second parallel determination get in the same way on the second photographic plate.

Table 7E

The difference between the larger and the smaller of the results of the parallel element definitions with confidence probability of 0.95 does not exceed the permissible differences given in table.7G and table.7з.

If this standard is met, calculate the result of the analysis is the average of the two results of parallel measurements.

Table 7G

Allowable differences for intermediate values of the mass fraction of impurities not specified in the table, find using linear interpolation.

4.3.2.4. Control the correctness of the results — p. 4.2.4.5.

4.3.3. Extraction-photometric method for the determination of tantalum (from 0.02 to 0.10%)

The method is based on measuring the optical density of the toluene extract of fortuntate brilliant green.

4.3.3.1. Apparatus, materials and reagents

Analytical scale.

Table 7з

Tile electric laboratory with a closed spiral with a capacity of 3 kW.

Centrifuge laboratory, brand of CLK-1 or similar.

The photoelectric concentration colorimeter KFK-2 or similar.

Pipettes 1−2-2; 2−2-5; 2−2-10; 2−2-20; 2−2-25; 2−2-50; 6−2-10 according to GOST 20292−74*.
________________
* On the territory of the Russian Federation there are 29169−91 GOST, GOST 29227−91−29229−91 GOST, GOST 29251−91-GOST 29253−91, here and hereafter. — Note the manufacturer’s database.

Cylinders 1−500; 1−2000 according to GOST 1770−74.

Burette 6−2-5; 1−2-100 according to GOST 20292−74.

Bulb 2−100−2; 2−200−2; 2−500−2 according to GOST 1770−74.

Glass-1−100 TC GOST 25336−82.

The Teflon beaker with a spout with a capacity of 100 cm.

Bank bn-0,5, GOST 17000−71.

Cans BDC-5,0 GOST 17000−71.

Tube made of plastic according to GOST 1770−74.

The cylinders are made of polyethylene with a capacity of 60 cm.

Centrifuge tubes made of polyethylene with a capacity of 10 cm.

Pipettes made of polyethylene with a capacity of 10 cm.

Sulfuric acid GOST 4204−77, H. h, a solution of 5 mol/land 1.4 mol/DM.

Nitric acid GOST 4461−77, H. h

Hydrofluoric acid according to GOST 10484−78, H. h, a solution of 7.5 mol/DM.

Solution for washing of the extracts with concentrations of sulfuric acid and 1.18 mol/land hydrofluoric acid 0.98 mol/DM. To prepare 5 DMof solution in a plastic pail placed 245 cmof a solution of hydrofluoric acid of 20 mol/DM, 1175 cmof sulfuric acid solution 5 mol/DM, 3580 cmof distilled water and stirred for 30−40 C.

Brilliant green, h, a solution of 3 g/DM, is prepared by dissolving 3 g of dye in 1 DMof water on cold for 1 h with stirring using an Electromechanical stirrer.

Toluene according to GOST 5789−78, h.d. a.

Acetone according to GOST 2603−79, h.d. a.

Ammonium sulfate according to GOST 3769−78, H. h

Tantalum powder (high purity), with a mass fraction of tantalum is not less than 99.5%.

Distilled water for TH

ST 6709−72.

4.3.3.2. Preparation for measurement

4.3.3.2.1. Preparation of the main solution and working solutions

Stock solution of tantalum pentoxide 0,200 g/DM: a portion of the metal tantalum powder 0,0819 g, weighed to ±0.0005 g, placed in a Teflon beaker, add plastic pipette 5.0 cmof concentrated hydrofluoric acid, 0.5 cmof nitric acid, heated on a heating plate until complete dissolution of the sample and evaporated to a volume of 1−2 cm. The solution was transferred to volumetric flask with a capacity of 500 cm, which had previously placed 250 cmof distilled water, adjusted to the mark and stirred for 30−40 C. the Prepared solution stored in a plastic container.

Working solutions of tantalum pentoxide is 2.0 and 20.0 µg/cmpipetted 2.0 and 20.0 cmcore solution in a volumetric flask with a capacity of 200 cm, add 56,0 cmof sulfuric acid solution 5 mol/l, adjusted to the mark with water and stirred for 30

40 C.

4.3.3.2.2. Construction of calibration curve

In the polyethylene ampoule is placed from burette 2,0; 4,0; 6,0; 8,0; 10,0 cmworking solution of 2.0 mg/cmand 1,0; 2,0; 3,0; 4,0; 5,0 cmworking solution of 20.0 µg/cm. Bring the sulfuric acid concentration of 1.4 mol/DM(2,8 m) to 10.0 cm, plastic pipette add 1.5 cmof a solution of hydrofluoric acid 7.5 mol/DM, 25,0 cmof toluene, is added from burette 11.0 cmof brilliant green solution and shaken for 60 s on Electromechanical shaker or manually. After separation of the phases within 60 to 90 with 10 cmof the extract was placed in a centrifuge tube and centrifuging for 3 min with a speed of 3000 min.

The optical density was measured at KFK-2 in cuvettes with a layer thickness of 5.0 mm absorption in the range of 20−100 micrograms of tantalum pentoxide and 30.0 mm in the range of 4−20 µg of tantalum pentoxide with (590±10) nm. A solution of comparison used toluene.

At the same time through all stages of the two parallel spend control experience. The optical density of control experience of not more than 0.03 in a ditch of 30 mm and 0.005 — 5 mm. in the cell According to the received data build two calibration g

Rafik.

4.3.3.3. Measurements

The sample mass 0,1000 g, weighed with accuracy up to 0,0005 g, placed in a Teflon beaker, add plastic pipette 10 cmof concentrated hydrofluoric acid, then pipette 2.0 cmof nitric acid and 8.0 cmof concentrated sulfuric acid, heated on a tile to start the selection of vapors of sulfuric acid, then continue heating for another 2−3 min. the Glasses are cooled to a temperature of (25±5) °C, add 3.0 g of ammonium sulfate, dilute with water to 10 cmand transferred to volumetric flask with a capacity of 100 cm, bring to the mark with water and mix 30−40.

Aliquot part of the obtained solution containing 4−100 µg of tantalum pentoxide, was placed in a plastic cylinder with a capacity of 60 cm, adjusted with sulfuric acid solution of concentration 5 mol/lto 10.0 cm, add 1.5 cmof a solution of hydrofluoric acid concentration of 7.5 mol/DMand leave for 8−10 min. Then added to the pipette 25,0 cmof toluene, 11.0 cmof a solution of brilliant green and produce extraction as described in section 4.3.3.2. After separation the phases were separated and the extract in the amount of 20−25 cmoff. Add 10.5 cmsolution for washing of the (plastic pipette), 10.0 cmof a solution of brilliant green from a burette and shaken as described in step 4.3.3.2. After separation the phases were separated and the extract of at least 16,0 cmagain subjected to a cleaning operation. After separation of the phases 10 cmof the extract was placed in a centrifuge tube and centrifuging for 3 min at a speed of 3000 rpm.

The optical density of the extract is measured at KFK-2, as described in section 4.3.3.2.2. In closed plastic test tubes extracts is stable for 4 h. allowed carrying out the extraction and washing of the extracts simultaneously in sixteen tubes. A lot of tantalum pentoxide is determined by graduirovannam

mu schedule.

4.3.3.4. Processing of the results

Mass fraction of tantalum in percent is calculated by the formula

,

where is the mass of tantalum pentoxide, was found in the calibration schedule, mcg;

 — weight of sample, g;

 — aliquota part of the solution was selected for extraction, cm;

 — volume of the volumetric flask of 100 cm;

1,221 — factor.

The measurement result should be the arithmetic mean of the results of two parallel measurements.

The permissible discrepancy between two parallel definitions should not exceed the values of permissible differences given in table.7.

Table 7

4.3.3.5. Control of the correctness of the analysis

Control of the correctness analysis is carried out by additives.

Total mass fraction of tantalum in the sample with the additive should be at least tripled lower boundary value determined by a mass fraction and not more than the upper boundary of the detectable concentrations.

The total content of tantalum in the sample with the additive percentages is calculated by the formula

,

where  — mass fraction of tantalum in the alloy, %;

 — weight of tantalum, introduced with the Supplement, mcg;

 — the weight of the portion of the sample,

Analysis think is right (0,95), if the difference between the larger and the smaller of the two quantities and the result of the analysis of the sample with the additive does not exceed

,

where  — the allowable difference between the results of two parallel measurements in the sample without the additive;

 — permissible difference between results of two parallel measurements in the sample with the additive.

4.3.1−4.3.3.5. (Added, Rev. N 1).

4.4. Determination of specific surface

4.4.1. Specific surface area niobium powder is determined by the device ADP-1 or T-3 method of air permeability, which measured the duration of prosushivanija a certain volume of air through the layer of powdered material, depending ceteris paribus on the magnitude of the specific surface.

4.4.2. Determination of specific surface on the device ADP-1

4.4.2.1. Determination of the mass of the sample

Sample mass , g, is determined by the formula where 3,33, 2.

 — density niobium powder, equal of 8.57 g/cm.

Then 57 g. Sample is weighed with an error not more than 0.01 g.

The specific surface area determined by the formula

,

where is the constant of the instrument,

 — the amount dependent on the air temperature and the height of the layers of the sample , is found from tables of the user to the device.

* where  — the height of the layer of sample 2.
________________
* Formula conforms to the original. — Note the manufacturer’s database.

 — time pressure measurement within the prescribed limits of the scale of the manometer, p

(Changed edition, Rev. N 1)

.

4.4.2.2. Equipment — GOST 23620−79.

4.4.2.3. Analysis — according to GOST 23620−79.

4.4.2.4. Processing of the results — according to GOST 23620−79, with the Supplement.

The permissible discrepancy between the results of the analysis in the determination of the specific surface area of at least 500 cm/g is 7% Rel.

(Changed edition, Rev. N 1).

4.4.3. Determination of specific surface on the device T-3

4.4.3.1. Determination of the mass of the sample

Sample mass is determined based on the size of the calibrated casings of the device.

4.4.3.2. Equipment

Device T-3.

The stopwatch according to GOST 5072−79.

Thermometer according to GOST 27544−87.

4.4.3.3. Analysis

Sample mass of niobium powder, dried at 100 °C for 30 min, weighed with an accuracy of at least 0.01 g, placed in a casing of the device, the bottom of which is placed a perforated disk, on top of which a circle of filter paper.

Record the temperature of the surrounding air.

Tapping within 30−60 with powder is spread, compacted and covered on top with a circle of filter paper.

The powder is compacted by the plunger as long as the Circlip plunger will not come into contact with the upper edge of the sleeve.

A sleeve attached to the manometer to aspirator and include water-jet pump or other source of vacuum.

Open the faucet. Fluid into the closed knee pressure gauge-suction should rise to the height of the upper level marked on the tube.

Then prosushivayut air through a powder layer (closing the faucet) located in the sleeve.

4.4.3.4. Processing of the results

The specific surface of the powder of niobium , cm/g, is calculated by the formula

,

where is the constant of the instrument specified in the passport of the device or determined by the powder with known specific surface is attached to the device;

 — density niobium powder, g/cm,

the porosity of the powder fraction;

 — time reduction of the fluid level above the upper extension to the level between the two extensions;

 — the viscosity of air at temperature experience, P.

For continuous monitoring of niobium powder specific surface area calculated by the formula

,

where

.

4.5. Granulometric composition of the powders of the first and fourth grades and very valuable fractions of the second and third classes define the sieve method according to GOST 18318−73*.
______________
* On the territory of the Russian Federation GOST 18318−94. — Note the manufacturer’s database.

4.5.1. Equipment

A set of sieves according to GOST 6613−86 with the size of cells 1,0; 0,20; 0,14; 0,10; 0,071; 0,063; 0,040 mm.

Analyzer sieve, vibrating 236Б-G or similar type.

4.5.2. Analysis

Depending on the class of powder select a set of sieves with their location in decreasing the cell size (largest at the top).

100 g of niobium powder, weighed with an accuracy of at least 0.1 g, placed on the top sieve. A set of sieves with the sample mounted on the sieve analyzer, and include a time relay.

Sieving of powder is carried out for 20−30 min.

4.5.3. Processing of the results

Mass fraction of residue powder of niobium on the sieve , %, is calculated by the formula

,

where  — mass of the sieve residue, g;

 — the weight of niobium powder,

The analysis result should be the arithmetic mean of two parallel definitions, allowable differences between them should not exceed specified in table.7K.

Table 7K

4.5.2; 4.5.3. (Changed edition, Rev. N 1).

4.6. Granulometric composition of the powders of the second and third classes of the negative fractions was determined by photosedimentation.

4.6.1. Sampling and sample preparation — according to GOST 22662−77.

4.6.1.1. To remove large particles from the dried sample is sieved through sieve N 0063 mesh according to GOST 6613−86.

4.6.1.2. A sample taken in the quantity necessary for preparation of the suspension with powder concentration of 0.3−0.45%, which corresponds to the position of the potentiometer from 0 to 5 mV.

For powders of the second and third classes, the mass of the sample should be accordingly — 2, 3 g and 1.6 g (depending on the amount of fine fraction).

The sample is weighed with an error not more than 0.01 g.

4.6.2. Photosedimentation method

4.6.2.1. The essence of the method — according to GOST 22662−77.

4.6.2.2. Equipment and reagents

Photosedimentometer types of AFS-2, AFS-3, FSM-70 or similar device.

Libra.

Water jet or vacuum pump.

Thermometer according to GOST 27544−87.

The stopwatch according to GOST 5072−72.

The metallographic microscope type h-3 or similar with magnification of 400.

Set of hydrometers.

The metal ruler according to GOST 427−75.

Glycerin according to GOST 6259−75, h. d. a. or h

Sodium hexametaphosphate.

Rectified ethyl alcohol GOST 18300−87.

Dispersion liquid, 30−50% solution of glycerol in water.

The volume of the dispersion liquid is 500 cm.

(Changed edition, Rev. N 1).

4.6.3. Preparation for assay

4.6.3.1. Selection of the dispersion liquid

According to the Stokes equation governs the time for sedimentation of the largest particles of powder is detected by microscopic analysis , since, according to the formula

,

where is the viscosity of the fluid, P;

 — sedimentation height, cm (32 cm);

 — free fall acceleration, cm/s;

 — micrometrically density of powder, g/cm;

is the fluid density, g/cm;

 — particle diameter, cm

This time should not be less than 40 C. At time less than 40 sec. select the more viscous dispersion liquid. The time of sedimentation of large particles is multiplied by a factor of 1.11; the number you typed on the panel when

Bora.

4.6.3.2. The density of the dispersion liquid is determined according to GOST 22662−77 or hydrometer.

4.6.3.3. The viscosity of the dispersion liquid must be expressed with an accuracy of 0.001 P.

4.6.3.4. The height of the subsidence is defined as the distance from the top edge of the suspension to the plane of measurement (32 cm).

4.6.4. Analysis

4.6.4.1. Preparation of a suspension of powder

The sample is placed in a porcelain Cup, add sodium hexametaphosphate 0.05 g, 3−5 cmdispersion liquid (allowed instead of sodium hexametaphosphate to add 3−5 cmof ethanol).

A sample of the powder was triturated for at least 2 min, to prevent any crushing of the individual particles of the powder, then diluted dispersion liquid and transferred to the cuvette.

Bring the suspension volume to the mark corresponding to the height of 32 cm, the cuvette is installed in the socket of the device and the suspension was stirred for 2−3 min, avoiding the formation of bubbles.

After mixing the powder should be evenly distributed over the height of the cell.

4.6.4.2. The device is switched on by pressing button «AUTO» and starts the registration process of the sedimentation of particles, removed, photosedimentometer. At the initial moment of the registration arrow of the potentiometer must be in the range of 0−5 mV range of the instrument.

If when setting the cuvette into the slot of the device pointer of the device shows more than 5 mV, the dispersion liquid is added a small amount of powder (0.1−0.2 g) prepared according to claim 4.6.4.1.

When deflection to the left of the zero indication you need to take a sample a little smaller than the original (the sample mass is determined experimentally).

4.6.4.3. The end of the process the photometry data is recorded by turning the green light bulb. Thereafter, the carriage with the photometric device is returned to the original position and remove the second photosedimentometer.

Photosedimentometer consists of nine steps. Each step corresponds to the total of the projection areas of particles of this fraction on a plane perpendicular to the beam of light.

4.6.5. Processing of the results

4.6.5.1. Calculation photosedimentometer

Photosedimentometer calculation is carried out in accordance with the specification of the device.

For the results analysis be the arithmetic mean of two parallel definitions.

The allowable divergence of the two parallel definitions depend on the fraction of the powder (tab.8) at a confidence probability of 0.95.

Table 8

5. PACKING, MARKING, TRANSPORTATION AND STORAGE

5.1. Niobium powder forms I-III are Packed in plastic jars with screw caps capacity 1 or 5 DMmade in NTD or in consumer packaging for NTD. Plastic cans are Packed in boxes of the type P-1 and P-2 according to GOST 2991−85. To prevent movement of cans inside the box set stencil cut from polyethylene or other material in the form of cans and box, or wooden spacer bars. Allowed free space boxes to fill with sawdust, shavings or rags. The size of the box according to GOST and GOST 18573−86 21140−88 (380х190х304±10), (380х190х317±10) mm, gross weight not over 50 lbs. Boxes must be banded in accordance with GOST 2991−85 wire according to GOST 3282−74 or metal tape according to GOST 3560−73, bonded in a «lock» or overlap.

Niobium powder class IV is Packed in bags of polyethylene film according to GOST 10354−82 with thickness not less than 0.06 mm, made in NTD or in polyethylene bags according to GOST 17811−78; which brewed and packaged in steel drums with detachable lid, made according to GOST 25750−83, or in boxes of the type P-1 and P-2 according to GOST 2991−85. The gross weight of the box should be no more than 50 kg, the gross weight of the drum — 500 kg.

On demand of the consumer is allowed to attach a bag made of polyethylene film according to GOST 10354−82 in consumer packaging and plastic cans.

For products intended for long-term storage, the document certifying its quality, must be attached to each packing location.

5.2. Transport marking — according to GOST 14192−77* (main, additional and informational inscriptions) indicating the manipulation of the sign «Afraid of heat» and a sign of danger to hazard class 4, division 4.1, classification code 4111 according to GOST 19433−88. On the lid of each box or barrel (drum) labeling, comprising:
_______________
* On the territory of the Russian Federation GOST 14192−96. — Note the manufacturer’s database.

the name and code of the product pigment, or the label,

batch number.

In each box or drum put a label indicating:

name or cipher of the products;

class of powder;

batch number;

the weight of one container space;

the date of manufacture.

stamp of the controller of the technical control Department;

designation of this standard.

5.3. Niobium powder transporterowych small shipments by railway and motor transport in covered vehicles in accordance with the rules of transportation of cargoes effective for this transport.

When transporting two or more units of product packaging the packaging load — according to GOST 21650−76, 24597−81 GOST, GOST 26381−84.

5.1−5.3. (Changed edition, Rev. N 1).

5.4. Niobium powder is stored in the manufacturer’s packaging in covered warehouses.