GB/T 3286.1-2012 English PDF (GBT3286.1-2012)

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GB/T 3286.1-2012: Methods for chemical analysis of limestone and dolomite -- Part 1: The determination of calcium oxide and magnesium oxide content -- The complexometric titration method and the flame atomic absorption spectrometric method
GB/T 3286.1-2012
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 73.080
D 52
Replacing GB/T 3286.1-1998
Methods for chemical analysis of limestone and dolomite -
Part 1: The determination of calcium oxide and magnesium
oxide content - The complexometric titration method and the
flame atomic absorption spectrometric method
ISSUED ON: NOVEMBER 05, 2012
IMPLEMENTED ON: MAY 01, 2013
Issued by: General Administration of Quality Supervision, Inspection and
Quarantine of the People's Republic of China;
Standardization Administration of the People's Republic of
China.
Table of Contents
Foreword ... 3
1 Scope ... 5
2 Normative references ... 5
3 Complexometric titration method ... 6
4 Flame atomic absorption spectrometric method ... 18
5 Test report ... 23
Annex A (normative) Flow chart of the acceptance procedure of sample
analysis results ... 24
Annex B (informative) Function relationships and raw data of precision test . 25
Methods for chemical analysis of limestone and
dolomite - Part 1: The determination of calcium oxide
and magnesium oxide content - The complexometric
titration method and the flame atomic absorption
spectrometric method
WARNING: Personnel using this Part shall have formal laboratory work
experience. This Part does not point out all possible safety issues. It is
the responsibility of the user to take appropriate safety and health
measures and ensure compliance with the conditions specified by
relevant national laws and regulations.
1 Scope
This Part of GB/T 3286 specifies the determination of calcium oxide and
magnesium oxide content by complexometric titration method and the
determination of magnesium oxide content by atomic absorption spectrometric
method.
This Part applies to the determination of calcium oxide content and magnesium
oxide content in limestone and dolomite. It also applies to the determination of
calcium oxide content and magnesium oxide content in metallurgical lime.
Complexometric titration method, determination range (mass fraction): calcium
oxide content is greater than 20 %, magnesium oxide content is greater than
2.5 %; atomic absorption spectrometric method, determination range (mass
fraction): magnesium oxide content is 0.1 % ~ 2.5 %.
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 2007.2 General rules for the sampling and sample preparation of
titrate the combined content of calcium oxide and magnesium oxide; or mask
the calcium with slightly excessive EGTA standard titration solution, and use
cyclohexane diamine tetraacetic acid (CyDTA) standard titration solution to
titrate the magnesium oxide content.
For samples of which the iron oxide and alumina content is greater than 2.0 %
or the manganese oxide content is greater than 0.10 %, use sodium
diethylamine dithioformate (copper reagent) to precipitate and separate iron,
aluminum and manganese ions, and take the filtrate to titrate the calcium oxide
content and magnesium oxide content with EDTA or EGTA and CyDTA standard
titration solutions.
3.2 Reagents
Unless otherwise specified in the analysis, only approved analytical reagents
and distilled water of grade 3 or higher or water of equivalent purity that meets
the requirements of GB/T 6682 shall be used.
3.2.1 Mixed flux: TAKE two portions of anhydrous sodium carbonate and one
portion of boric acid, MIX well.
3.2.2 Hydrochloric acid (1 + 5).
3.2.3 Triethanolamine (1 + 4).
3.2.4 Ammonia water (1 + 1).
3.2.5 Potassium hydroxide solution (200 g/L), stored in plastic bottles. After
preparation, it shall be placed for more than 12 h before use.
3.2.6 Sodium diethylamine dithioformate (copper reagent) solution (50 g/L).
3.2.7 Ammonia buffer solution (pH10): WEIGH 67.5 g of ammonium chloride
and DISSOLVE in water, ADD 570 mL of ammonia water (ρ = 0.90 g/mL),
DILUTE to 1 L with water, MIX well.
3.2.8 Calcium indicator (calcium carboxylic acid): TAKE 1 g of calcium indicator
and GRIND with 100 g of sodium chloride, MIX well.
3.2.9 Acid chrome blue K-naphthol green B mixed indicator solution: TAKE 0.5
g of acid chrome blue K and 0.2 g of naphthol green B, DISSOLVE in water,
DILUTE to 70 mL with water.
NOTE: The ratio of acid chrome blue K and naphthol green B can be appropriately adjusted
according to the color development sensitivity of the indicator and the color discrimination ability
of the operator.
(mL);
V2 - the average value of the volume of EDTA standard titration solution
consumed in the titration, in milliliters (mL);
V02 - the average value of the volume of EDTA standard titration solution
consumed by the titration reagent blank, in milliliters (mL).
3.2.13 EGTA (ethylene glycol tetraacetic acid) standard titration solution
[c(EGTA) = 0.01 mol/L]
3.2.13.1 Preparation
WEIGH 3.90 g of EGTA, PLACE it in a 500 mL beaker, ADD about 250 mL of
water, HEAT at low temperature, dropwise ADD potassium hydroxide solution
(3.2.5) under constant stirring until the reagent is dissolved, and COOL to room
temperature. TRANSFER to a 1000 mL volumetric flask, DILUTE with water to
the mark, and MIX well.
3.2.13.2 Calibration of the titer of EGTA standard titration solution to
calcium oxide
Same as the calibration of the tire of EDTA standard titration solution to calcium
oxide. OPERATE according to 3.2.12.2 and CALCULATE the titer T3. USE
EGTA standard titration solution (3.2.13.1) instead of EDTA standard titration
solution (3.2.12.1).
3.2.14 CyDTA (cyclohexane diamine tetraacetic acid) standard titration
solution [c(CyDTA) = 0.01 mol/L]
3.2.14.1 Preparation
WEIGH 3.70 g of CyDTA, PLACE it in a 500 mL beaker, ADD about 250 mL of
water, HEAT at low temperature, dropwise ADD potassium hydroxide solution
(3.2.5) under constant stirring until the reagent is dissolved, and COOL to room
temperature. TRANSFER to a 1000 mL volumetric flask, DILUTE with water to
the mark, and MIX well.
3.2.14.2 Calibration of the titer of CyDTA standard titration solution to
magnesium oxide
Same as the calibration of the tire of EDTA standard titration solution to
magnesium oxide. OPERATE according to 3.2.12.3 and CALCULATE the titer
T4. USE CyDTA standard titration solution (3.2.14.1) instead of EDTA standard
titration solution (3.2.12.1).
3.3 Instruments
NOTE: This test solution can be used as a stock solution for the determination of calcium oxide,
magnesium oxide, silicon dioxide, aluminum oxide and iron oxide. It can be used for GB/T
3286.1 the determination of calcium oxide and magnesium oxide content by complexometric
titration method, GB/T 3286.2 the determination of silicon dioxide content by silicomolybdic blue
spectrophotometric method, GB/T 3286.3 the determination of aluminium oxide content by
chrome azurol S spectrophotometric method, GB/T 3286.4 the determination of iron oxide
content by o-phenanthroline spectrophotometric method. If the content of these chemical
components in the sample are determined at the same time, it may prepare only one portion of
stock solution of the sample, and then the stock solution is divided for the determination
according to each analysis method.
3.5.4.3 TAKE two portions of 25.00 mL of stock solution (3.5.4.2) (it may take