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This standard is drafted in accordance with the rules given in GB/T 1.1-2009.
This standard replaces GB/T 176-2008 Methods for chemical analysis of cement, and the following main technical changes have been made with respect to GB/T 176-2008:
—— The inductively coupled plasma emission spectrometry is added to the scope (see clause 1 of this standard, and clause 1 of Edition 2008).
—— “Unless otherwise stated, the loss on ignition shall be determined while chemical analysis is carried out" is modified to "It is recommended to determine the loss on ignition while chemical analysis is carried out." (see 4.1 of this standard and 4.1 of Edition 2008).
—— "Unless otherwise stated, the validity period of the standard volumetric solution is 3 months. If it exceeds 3 months, the solution shall be calibrated again." is added (see 4.8 of this standard).
—— In the preparation of specimens "to completely pass through a square-mesh sieve with a pore diameter of 80 μm" is modified to "to completely pass through a square-mesh sieve with a pore diameter of 150 μm". "The metallic iron in the sieve residue shall be removed by magnet" is modified to "If the metallic iron brought in during the preparation may affect the determination of relevant chemical property, the metallic iron in the sieve residue shall be removed by magnet". "Before analyzing specimens of cement and cement clinker, there is no need to dry the specimens" is added to the note (see clause 5 of this standard and clause 7 of Edition 2008).
—— In the calibration of sodium thiosulfate standard solution, "potassium dichromate standard volumetric solution” is changed to "potassium iodate standard volumetric solution" (see 6.1.85.2 of this standard and 5.84.2 of Edition 2008).
—— Determination of loss on ignition is divided into "determination of loss on ignition of cement" and "determination of loss on ignition of portland slag cement". In the determination of loss on ignition of portland slag cement, specific requirements are set forth for the determination method of sulfate sulfur trioxide in the test portion after ignition (see 6.3, 6.4, and 6.39 of this standard, and clause 8 of Edition 2008).
—— "Sulfur trioxide" is modified to "sulfate sulfur trioxide" (see 6.5, 6.28, 6.29, and 6.30 of this standard, and clauses 10, 30, 31, and 33 of Edition 2008).
—— In the determination of sulfate sulfur trioxide - barium sulfate gravimetric method (reference method), the decomposition time of the specimen is changed from "slightly boiling for (5±0.5) min" to "slightly boiling for 5 min ~ 10 min” (see 6.5 of this standard, and clause 10 of Edition 2008).
—— In the determination of insoluble matter - hydrochloric acid-sodium hydroxide treatment, “Proceed the next wash after the washings has completely passed through the filter paper” is added following "fully wash the residue and filter paper with hot ammonium nitrate solution for at least 14 times” (see 6.6 of this standard, and clause 9 of Edition 2008).
—— In the determination of silica - ammonium chloride gravimetric method (reference method), the ignition temperature of silica precipitation is changed from "ignite it in a high-temperature furnace at 950℃ ~ 1,000℃ for 60 min" to "ignite it in a high-temperature furnace at (1,175±25) ℃ or 950℃~1,000℃ for 1 h [in case of any dispute, the results gained after igniting at (1,175±25) ℃ shall prevail]" (see 6.7 of this standard, and clause 11 of Edition 2008).
—— For the determination of iron(III) oxide, the o-phenanthroline spectrophotometry is changed to the reference method, and EDTA direct titration method is changed to the alternative method (see 6.8 and 6.21 of this standard, and clauses 12 and 24 of Edition 2008).
—— For the determination of aluminum oxide, iron-aluminum resultant titration with EDTA is added as the reference method, and EDTA direct titration method is changed to the alternative method (see 6.9 and 6.23 of this standard, clause 13 of Edition 2008).
—— In the determination of magnesium oxide - atomic absorption spectrophotometry (reference method), the method of melting specimen with sodium carbonate is added (see 6.11.2.3 of this standard).
—— In decomposing specimen with hydrofluoric acid-perchloric acid for determination of magnesium oxide - atomic absorption spectrophotometry (reference method), polytetrafluoroethylene dish is added to decompose the specimen (see 6.11.2.1 of this standard, and 15.2.1 of Edition 2008).
—— In decomposing specimen for determination of potassium oxide and sodium oxide - flame photometry (reference method), polytetrafluoroethylene dish is added to decompose the specimen (see 6.14.2 of this standard, and 17.2 of Edition 2008).
—— In the determination of carbon dioxide - caustic asbestos absorption gravimetric method, the analytical procedure is canceled that "if the mass change of the second U-shaped tube 12 continuously exceeds 0.001 0 g, the first U-shaped tube 11 shall be replaced and the test shall be restarted" (see 6.18 of this standard, and clause 22 of Edition 2008).
—— Determination of zinc oxide - atomic absorption spectrometry is added (see 6.19 of this standard).
—— In the determination of silica - potassium fluosilicate volumetric method (alternative method), "add 10 mL to 15 mL of nitric acid" is changed to "add 15 mL of nitric acid"; "Place the solution at 30 ℃ for 15 min to 20 min" is changed to "Place the solution at a temperature of 10 ℃ to 26 ℃ for 15 min to 20 min" (see 6.20 of this standard, and clause 23 of Edition 2008).
—— In the determination of iron(III) oxide - EDTA direct titration (alternative method), "pH 1.8 ~ 2.0" is changed to "pH 1.8" (see 6.21 of this standard, and clause 12 of Edition 2008).
—— In the determination of aluminum oxide - copper sulfate back titration (alternative method), it is added that if the consumption of copper sulfate standard volumetric solution is less than 10 mL, increase the amount of EDTA standard volumetric solution added and test again (see 6.24 of this standard, and clause 26 of Edition 2008).
—— In the determination of sulfate sulfur trioxide - coulometric titration (alternative method), "In addition to sulfide (S2-) and sulfate, there are other forms of sulfur in the specimen, which will cause errors to the determination results" is modified to "If the specimen contains a large amount of sulfide (S2-) or sulfur in other forms, it is possible that the sulfide or sulfur in other forms is not completely decomposed by formic acid, which will cause positive errors to the determination results, such as cement mixed with a large amount of slag." (see 6.29 of this standard, and clause 33 of Edition 2008).
—— In the determination of sulfate sulfur trioxide - ion exchange method (alternative method), the requirement is added that "This method is only used for enterprise production control" (see 6.30 of this standard, and clause 31 of Edition 2008).
—— Determination of sulfur trioxide - barium chromate spectrophotometry (alternative method) is deleted (see clause 32 of Edition 2008).
—— Determination of chloride ions - (automatic) potentiometric titration (alternative method) is added (see 6.31 of this standard).
—— Determination of chloride ion - ion chromatography (alternative method) is added (see 6.32 of this standard);
—— Determination of chloride ions - phosphoric acid distillation-mercury salt titration (alternative method) is canceled (see clause 35 of Edition 2008).
—— In the determination of free calcium oxide - ethylene glycol method (alternative method), air suction and filtration after heating for 4 min in the analytical procedure are canceled and changed to titrate immediately after heating for 5 min (see 6.37 of this standard, and clause 39 of Edition 2008).
—— Determination of free calcium oxide - ethylene glycol extraction-EDTA titration (alternative method) is added (see 6.38 of this standard).
—— Determination of loss on ignition of portland slag cement - correction method (alternative method) is added (see 6.39 of this standard).
—— Determination of total sulfur in portland cement raw meal is added (see 6.40 of this standard).
—— Modification is made to the repeatability limit and reproducibility limit for the determination results of methods for chemical analysis of cement (see 6.41 of this standard, and clause 41 of Edition 2008).
—— The contents of "Building and verification of calibration curves and equations" in X-ray fluorescence analysis method are modified and supplemented (see clause 7 of this standard, and clause 40 of Edition 2008).
—— Determination of the following by inductively coupled plasma mass spectrometry is added: iron(III) oxide, aluminum oxide, magnesium oxide, titanium oxide, potassium oxide, sodium oxide, manganese oxide, zinc oxide, phosphorus pentoxide, and sulfate sulfur trioxide (see clause 8 of this standard).
This standard is redrafted by reference to and not equivalent to ISO 29581-1: 2009 Cement - Test methods - Part 1: Analysis by wet chemistry
This standard was proposed by China Building Materials Federation.
This standard is under the jurisdiction of SAC/TC 184 National Technical Committee on Cement of Standardization Administration of China.
The previous editions of this standard are as follows:
—— GB/T 176-1956, GB/T 176-1962, GB/T 176-1976, GB/T 176-1987, GB/T 176-1996, and GB/T 176-2008;
—— GB/T 19140-2003.
Methods for chemical analysis of cement
1 Scope
This standard specifies the determination of loss on ignition (LOI), SO3, insoluble matter (IR), SiO2, Fe2O3, Al2O3, CaO, MgO, TiO2, Cl-, K2O, Na2O, S2-, MnO, P2O5, CO2, ZnO, F-, free calcium oxide (fCaO), and SrO by methods for chemical analysis of cement, X-ray fluorescence analysis method, and inductively coupled plasma optical emission spectrometry. Methods for chemical analysis of cement are divided into reference method and alternative method. If multiple determination methods are listed for the same component, the reference method shall prevail in case of any dispute.
This standard is applicable to common portland cement, the clinker and raw meal for preparing the said cement, and other types of cement and materials for which this standard is designated.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
GB/T 5762 Methods for chemical analysis of limestone, quicklime and hydrated lime for building materials industry
GB/T 6682 Water for analytical laboratory use - Specification and test methods
GB/T 8170 Rules of rounding off for numerical values & expression and judgment of limiting values
GB/T 12573 Sampling method for cement
GB/T 15000 (All parts) Directives for the work of reference materials
GSB 08-1110 X-ray fluorescence analysis of cement raw meal - Series reference sample
GSB 08-1355 Composition analysis of cement clinker - Reference sample
GSB 08-1356 Component analysis of ordinary portland cement - Reference sample
GSB 08-1357 Component analysis of ordinary portland cement - reference sample
GSB 08-2985 X-ray fluorescence analysis of cement - Series reference sample
3 Terms and definitions
For the purposes of this document, the terms and definitions given in GB/T 15000 (all parts) and the following apply.
3.1
repeatability conditions
conditions where independent test results are obtained on the same test object by the same operator using the same equipment according to the same method in the same laboratory in a short time
3.2
reproducibility conditions
conditions where test results are obtained on the same test object by different operators using different equipment according to the same method in different laboratories
3.3
repeatability limit
a value delimiting a probability of 95% that the absolute difference of two test results is less than or equal to it under the repeatability conditions (3.1)
3.4
reproducibility limit
a value delimiting a probability of 95% that the absolute difference of two test results is less than or equal to it under the reproducibility conditions (3.2)
3.5
series certified reference materials for x-ray fluorescence analysis
a complete set of reference samples associated with chemical compositions, which is used to calibrate analytical instruments such as X-ray fluorescence analyzer
4 General requirements for testing
4.1 Number of tests and requirements
The number of tests for determination of each chemical property shall be two. The absolute difference between the two results shall be within the repeatability limit (Tables 3, 4 and 5). The mean of the two test results shall be used to express the test result.
During routine production control analysis, determination of each chemical property by a single test shall be the minimum required.
It is recommended to determine the loss on ignition while chemical analysis is carried out.
Except for determination of loss on ignition, blank test shall be carried out in parallel, and the determination results shall be corrected.
4.2 Expression of masses, volumes, titers and results
Express masses in “grams (g)” to the nearest of 0.000 1 g and volumes from burettes in “milliliters (mL)” to the nearest of 0.01 mL. Express the titers of solutions in “milligrams per milliliter (mg/mL)”.
Express the titer of benzoic acid-anhydrous ethanol standard volumetric solution for calcium oxide with three significant figures, while the concentration, titer and volume ratio of other standard volumetric solutions with four significant figures.
Unless otherwise stated, all analysis results shall be based on mass fraction. The analysis result of chloride ion shall be expressed in % to three decimal places, and the analysis result of other items shall be expressed in % to two decimal places.
The rounding off of numerical value shall comply with the requirements of GB/T 8170.
4.3 Repeatability limit and reproducibility limit
The repeatability limit and reproducibility limit in this standard are expressed in mass fraction (%) as absolute deviation(s).
When the same specimen is analyzed by the methods given in this standard under the repeatability conditions (3.1), the difference between the two analysis results shall be within the repeatability limits listed (Tables 3, 4 and 5). If the repeatability limit is exceeded, a third determination shall be carried out in a short time. If the difference between the determination result and both or either of the previous ones meets the repeatability limit, the mean shall be taken. Otherwise, the reason shall be found and analysis shall be carried out again according to the above requirements.
When the same specimen is analyzed by the methods given in this standard under the reproducibility conditions (3.2), the difference between the two analysis results shall be within the reproducibility limits listed (Tables 3, 4 and 5).
4.4 Blank determinations
Carry out a blank determination without a specimen, following the same procedure and using the same amounts of reagents. Correct the results obtained for the analytical determination accordingly.
4.5 Ignition
Place the filter paper and its contents into a crucible that has been previously ignited and tared. Dry it, then incinerate slowly in an oxidizing atmosphere in order to avoid immediate flaming, while ensuring complete combustion. Ignite the crucible and its contents at the stated temperature, then allow it to cool to the room temperature in a desiccator (6.2.6). Weigh the crucible and its contents.
4.6 Constant mass
After the first ignition, cooling and weighing, determine constant mass by making successive 15 min ignitions followed each time by cooling and then weighing. Constant mass is reached when the difference between two successive weighing is less than 0.000 5 g.
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 General requirements for testing
4.1 Number of tests and requirements
4.2 Expression of masses, volumes, titers and results
4.3 Repeatability limit and reproducibility limit
4.4 Blank determinations
4.5 Ignition
4.6 Constant mass
4.7 Check for absence of chloride ions (silver nitrate test)
4.8 Reagents - General
4.9 Test method verification
5 Preparation of specimens
6 Chemical analysis methods
6.1 Reagents and materials
6.2 Instruments and apparatus
6.3 Determination of loss on ignition of cement - ignition subtraction method
6.4 Determination of loss on ignition of portland slag cement - correction method (reference method)
6.5 Determination of sulfate sulfur trioxide - barium sulfate gravimetric method (reference method)
6.6 Determination of insoluble matter - hydrochloric acid-sodium hydroxide treatment
6.7 Determination of silica - ammonium chloride gravimetric method (reference method)
6.8 Determination of iron(III) oxide - o-phenanthroline spectrophotometry (reference method)
6.9 Determination of aluminium oxide - iron-aluminium resultant titration with EDTA (reference method)
6.10 Determination of calcium oxide - EDTA titration method (reference method)
6.11 Determination of magnesium oxide - atomic absorption spectrophotometry (reference method)
6.12 Determination of titanium dioxide - diantipyrylmethane spectrophotometry
6.13 Determination of chloride ion - ammonium thiocyanate volumetric method (reference method)
6.14 Determination of potassium oxide and sodium oxide - flame photometry (reference method)
6.15 Determination of sulfides - iodometric method
6.16 Determination of manganese oxide - potassium periodate oxidation spectrophotometry (reference method)
6.17 Determination of phosphorus pentoxide - phosphomolybdate blue spectrophotometry
6.18 Determination of carbon dioxide - caustic asbestos absorption gravimetric method
6.19 Determination of zinc oxide - atomic absorption spectrometry
6.20 Determination of silica - potassium fluosilicate volumetric method (alternative method)
6.21 Determination of iron(III) oxide - EDTA direct titration method (alternative method)
6.22 Determination of iron(III) oxide - atomic absorption spectrophotometry (alternative method)
6.23 Determination of aluminum oxide - EDTA direct titration method
6.24 Determination of aluminum oxide - copper sulfate back titration (alternative method)
6.25 Determination of calcium oxide - sodium hydroxide melting - EDTA titration (alternative method)
6.26 Determination of calcium oxide - potassium permanganate titration (alternative method)
6.27 Determination of magnesium oxide - EDTA titration solution subtraction method (alternative method)
6.28 Determination of sulfate sulfur trioxide - iodometric method (alternative method)
6.29 Determination of sulphate sulfur trioxide - coulometric titration (alternative method)
6.30 Determination of sulfate sulfur trioxide - ion exchange method (alternative method)
6.31 Determination of chloride ion - (automatic) potentiometric titration (alternative method)
6.32 Determination of chloride ion - ion chromatography (alternative method)
6.33 Determination of potassium oxide and sodium oxide - atomic absorption spectrometry (alternative method)
6.34 Determination of manganese oxide - atomic absorption spectrophotometry (alternative method)
6.35 Determination of fluorine ion - ion selective electrode method
6.36 Determination of free calcium oxide - glycerol method (alternative method)
6.37 Determination of free calcium oxide - ethylene glycol method (alternative method)
6.38 Determination of free calcium oxide - ethylene glycol extraction-EDTA titration (alternative method)
6.39 Determination of loss on ignition of portland slag cement - correction method (alternative method)
6.40 Determination of total sulfur in portland cement raw meal
6.41 Repeatability limit and reproducibility limit for the determination results of methods for chemical analysis of cement
7 X-ray fluorescence analysis method
7.1 Principle
7.2 Reagents
7.3 Instruments and apparatus
7.4 Preparation of test piece
7.5 Calibration and verification
7.6 Calculation and expression of results
7.7 Repeatability limit and reproducibility limit for the determination results of X-ray fluorescence analysis method
8 Inductively coupled plasma - optical emission spectrometry (ICP-OES)
8.1 Principle
8.2 Reagents
8.3 Instruments and apparatus
8.4 Determination of iron(III) oxide, aluminum oxide, magnesium oxide, titanium oxide, potassium oxide, sodium oxide, manganese oxide, zinc oxide and phosphorus pentoxide
8.5 Determination of sulfate sulfur trioxide
8.6 Repeatability limit and reproducibility limit for the determination results of inductively coupled plasma - optical emission spectrometry
Annex A (Informative) Example for calculation of stoichiometric point for determination of chloride ion by potentiometric titration
Annex B (Informative) Reference chromatographic conditions and chromatograms of carbonate eluent
Annex C (Informative) Recommended wavelengths for inductively coupled plasma - optical emission spectrometry
