GB/T 26019-2010 Methods for chemical analysis of high impurity tungsten mineral—Determination of tungsten trioxide content—Twice separation and igniting gravimetric method (English Version)
Methods for chemical analysis of high impurity tungsten mineral—Determination of tungsten trioxide content—Twice separation and igniting gravimetric method
Methods for chemical analysis of high impurity tungsten mineral - Determination of tungsten trioxide content - Twice separation and igniting gravimetric method
1 Scope
This standard specifies the determination of tungsten trioxide content in high impurity tungsten mineral.
This standard is applicable to the determination of tungsten trioxide content in tungsten mineral with phosphorus content of less than 2%, titanium content of less than 1% and tin content of less than 2%. The determination range of tungsten trioxide is over 20%.
2 Principle
In the presence of a small amount of ammonium fluoride, the specimen is dissolved with hydrochloric acid, nitric acid and perchloric acid, concentrated until white smoke is emitted to remove excess fluoride ions and nitrate, tungsten is precipitated into tungstic acid, filtered, separated from most of the co-existing elements, tungstic acid is dissolved with aqueous ammonia, ferric nitrate and beryllium nitrate are added to precipitate and separate other impurities, and tungsten trioxide is weighed after the filtrate is evaporated, ignited, desilicated with hydrofluoric acid, and reignited. The tungsten trioxide content in residue is determined by spectrophotometry, and the result is corrected. When the molybdenum content is greater than 0.3%, the result needs to be corrected.
3 Reagents
Unless otherwise specified, analytically-pure reagents and distilled water meeting the requirements of national or professional standards shall be used for purpose of this part.
Foreword i 1 Scope 2 Principle 3 Reagents 4 Specimen 5 Analysis steps 6 Calculation of analysis results 7 Precision 8 Quality assurance and control
Standard
GB/T 26019-2010 Methods for chemical analysis of high impurity tungsten mineral—Determination of tungsten trioxide content—Twice separation and igniting gravimetric method (English Version)
Standard No.
GB/T 26019-2010
Status
valid
Language
English
File Format
PDF
Word Count
6000 words
Price(USD)
140.0
Implemented on
2011-10-1
Delivery
via email in 1 business day
Detail of GB/T 26019-2010
Standard No.
GB/T 26019-2010
English Name
Methods for chemical analysis of high impurity tungsten mineral—Determination of tungsten trioxide content—Twice separation and igniting gravimetric method
Methods for chemical analysis of high impurity tungsten mineral - Determination of tungsten trioxide content - Twice separation and igniting gravimetric method
1 Scope
This standard specifies the determination of tungsten trioxide content in high impurity tungsten mineral.
This standard is applicable to the determination of tungsten trioxide content in tungsten mineral with phosphorus content of less than 2%, titanium content of less than 1% and tin content of less than 2%. The determination range of tungsten trioxide is over 20%.
2 Principle
In the presence of a small amount of ammonium fluoride, the specimen is dissolved with hydrochloric acid, nitric acid and perchloric acid, concentrated until white smoke is emitted to remove excess fluoride ions and nitrate, tungsten is precipitated into tungstic acid, filtered, separated from most of the co-existing elements, tungstic acid is dissolved with aqueous ammonia, ferric nitrate and beryllium nitrate are added to precipitate and separate other impurities, and tungsten trioxide is weighed after the filtrate is evaporated, ignited, desilicated with hydrofluoric acid, and reignited. The tungsten trioxide content in residue is determined by spectrophotometry, and the result is corrected. When the molybdenum content is greater than 0.3%, the result needs to be corrected.
3 Reagents
Unless otherwise specified, analytically-pure reagents and distilled water meeting the requirements of national or professional standards shall be used for purpose of this part.
3.1 Sodium peroxide.
3.2 Ammonium fluoride.
3.3 Ethylenediamine tetraacetic acid disodium (EDTA).
3.4 Hydrochloric acid (ρ=1.19g/mL).
3.5 Nitric acid (ρ=1.42g/mL).
3.6 Hydrofluoric acid (ρ=1.15g/mL).
Contents of GB/T 26019-2010
Foreword i
1 Scope
2 Principle
3 Reagents
4 Specimen
5 Analysis steps
6 Calculation of analysis results
7 Precision
8 Quality assurance and control
