Standards related to:

GB/T 7737-2007GB/T 7737-2007

NATIONAL STANDARD OF THE

PEOPLE’S REPUBLIC OF CHINA

ICS 77.100

H 42

Replacing GB/T 7737-1997

Ferroniobium

ISSUED ON: SEPTEMBER 11, 2007

IMPLEMENTED ON: FEBRUARY 01, 2008

Issued by: General Administration of Quality Supervision, Inspection and

Quarantine;

Standardization Administration of the People's Republic of

China.

Table of Contents

Foreword ... 3

1 Scope ... 4

2 Normative references ... 4

3 Technical requirements ... 5

4 Test methods ... 6

5 Inspection rules ... 7

6 Packaging, storage, marks and quality certificate ... 8

Annex A (informative) Determination of arsenic, antimony, lead, tin, bismuth and

manganese in ferroniobium ... 9

Ferroniobium

1 Scope

This Standard specifies technical requirements, test methods, inspection rules,

packaging, storage, marks and quality certificate of ferroniobium.

This Standard is applicable to ferroniobium that is made from niobium pentoxide

and niobium concentrate and is used for steelmaking or casting as an additive,

for electrode as alloying agent, magnetic material.

2 Normative references

The provisions in following documents become the provisions of this Standard

through reference in this Standard. For dated references, the subsequent

amendments (excluding corrigendum) or revisions do not apply to this Standard,

however, parties who reach an agreement based on this Standard are

encouraged to study if the latest versions of these documents are applicable.

For undated references, the latest edition of the referenced document applies.

GB/ T 3650, The general rules for inspection packing storing transportation

marking and certification of ferroalloy

GB/T 3654.1, Methods for chemical analysis of ferroniobium. The paper

chromatographic gravimetric method for the determination of niobium and

tantalum content

GB/T 3654.3, Ferroniobium - Determination of silicon content - Gravimetric

method

GB/T 3654.4, Methods for chemical analysis of ferroniobium. The

combustion gravimetric method for the determination of carbon content

GB/ T 3654.5, Methods for chemical analysis of ferroniobium. The

molybdenum blue photometric method for the determination of the

phosphorus content

GB/T 3654.6, Ferroniobium - Determination of sulfur content - Combustion-

iodate titrimetric method, methylene blue photometric method and infrared

absorption method

GB/T 3654.7, Methods for chemical analysis of ferroniobium - The methylene

blue photometric method for the determination of sulfur content

Annex A

(informative)

Determination of arsenic, antimony, lead, tin, bismuth and manganese in

ferroniobium - Inductively coupled plasma emission spectroscopy

A.1 Scope

This annex specifies the method that uses inductively coupled plasma emission

spectroscopy to determine arsenic, antimony, lead, tin, bismuth, manganese in

ferroniobium.

This Annex is applicable to the determination of arsenic, antimony, lead, tin,

bismuth, manganese in ferroniobium. Determination range: the mass fraction

of arsenic, antimony, lead, tin, bismuth is 0.001%~1.0%; the mass fraction of

manganese is from 0.001%~2.0%.

A.2 Method summary

Use hydrofluoric acid and nitric acid to decompose the sample and dilute to a

certain volume. Through matrix matching, eliminate spectral interference.

Introduce atomized solution into the inductively coupled plasma emission

spectrometer. Determine the luminous intensity values of arsenic, antimony,

lead, tin, bismuth, manganese and other elemental analysis lines. Determine

the mass fraction of the corresponding element by the working curve method.

A.3 Reagents and materials

A.3.1 Hydrofluoric acid (G.R) grade.

A.3.2 Nitric acid (G.R) grade.

A.3.3 Nitric acid 4mol/L (G.R) grade.

A.3.4 Hydrochloric acid (G.R) grade.

A.3.5 Hydrochloric acid 4mol/L (G.R) grade.

A.3.6 Ferroniobium matrix (mass fractions of arsenic, antimony, lead, tin,

bismuth, and manganese are all less than 0.0001%).

A.3.7 Arsenic standard solution 1000μg/mL: Weigh 1.3203g of spectrally-pure

As2O3. Place in a 250mL beaker. Add 150mL of hydrochloric acid (A.3.5).

Slightly heat to dissolve. Move into a 1000mL volumetric flask. Use pure water

to dilute to the scale. Mix well.

volumetric flask. Add 1mL of nitric acid (A.3.2), 1mL of hydrochloric acid (A.3.4).

Use pure water to dilute to the scale. Mix well.

1mL of this solution contains 10μg of arsenic, antimony, lead, tin, bismuth and

manganese, respectively.

A.4 Instruments and equipment

A.4.1 Inductively coupled plasma emission spectrometer (ICP-AES, equipped

with hydrofluoric acid resistant injection system).

A.4.2 50mL Teflon beaker.

A.4.3 50mL Teflon volumetric flask.

A.4.4 Heating plate.

A.4.5 Analytical balance (1 in 10000).

A.5 Analysis steps

A.5.1 Preparation of standard and blank test solutions

Use the analytical balance (A.4.5) to weigh 5 portions of ferroniobium matrix

(A.3.6), 0.30g for each portion (to the nearest of 0.0001g). Place in a 50mL

Teflon beaker. Respectively add 2mL of pure water, 2mL of hydrofluoric acid

(A.3.1), 1mL of nitric acid (A.3.2). Place on the heating plate. Heat till the sample

is completely dissolved. Remove to cool. The 4 portions are added into the

standard solution according to the following requirements as standard solution

1, standard solution 2, standard solution 3 and standard solution 4. Add 0.30mL

of arsenic, antimony, lead, tin, bismuth and manganese mixed standard solution

(A.3.14) into standard solution 1. Add 0.30mL of arsenic, antimony, lead, tin,

bismuth, manganese mixed standard solution (A.3.13) into standard solution 2.

Add 0.30mL of arsenic standard solution (A.3.7), antimony standard solution

(A.3.8), lead standard solution (A.3.9), tin standard solution (A.3.10), bismuth

standard solution (A.3.11) respectively, 0.60mL of manganese standard

solution (A.3.12) into standard solution 3. Add 3.00mL of arsenic standard

solution (A.3.7), antimony standard solution (A.3.8), lead standard solution

(A.3.9), tin standard solution (A.3.10), bismuth standard solution (A.3.11)

respectively, 6.00mLof manganese standard solution (A.3.12) into standard

solution 4. Respectively move the above 4 solutions into 50mL PTFE volumetric

flasks. Use pure water to dilute to the scale. Mix well for testing. Move the rest

one portion into a 50mL Teflon volumetric flask. Use pure water to dilute to the

scale. Mix well as the blank test solution.

A.5.2 Preparation of test sample solution

Use the analytical balance (A.4.5) to weigh 0.30g of ferroniobium test material

...