GB/T 211-2017 (GB/T211-2017, GBT 211-2017, GBT211-2017) & related versions
Buy with any currencies (Euro, JPY, KRW...): GB/T 211-2017 Preview this PDF: GB/T 211-2017
GB/T 211-2017: PDF in English (GBT 211-2017)
GB/T 211-2017
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 73.040
D 21
Replacing GB/T 211-2007
Determination of Total Moisture in Coal
(ISO 589.2008, Hard Coal-Determination of Total Moisture, NEQ)
ISSUED ON. SEPTEMBER 7, 2017
IMPLEMENTED ON. APRIL 1, 2018
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 ... 4
2 Normative References ... 4
3 Method Summary ... 4
4 Reagent and Materials ... 5
5 Apparatus ... 5
6 Sample ... 6
7 Procedures ... 6
8 Precision of the Methods ... 10
9 Test Report ... 10
Appendix A (Informative) Determination of Total Moisture in Coal by Drying by
Microwave ... 12
Foreword
This Standard is drafted in accordance with GB/T 1.1-2009.
This Standard replaces GB/T 211-2007 “Hard Coal - Determination of Total Moisture”.
In comparison with GB/T 211-2007, in addition to editorial changes, the main technical
content changes are as follows.
— Method C (drying by microwave) is deleted (please refer to 3.3 in Version 2007);
— 13mm sample is added to Method B1 (please refer to 3.2.1 in Version 2007);
— Moisture loss correction of dry air during the sampling is added (please refer to
7.4);
— Informative appendix (determination of total moisture in coal through the method
of drying by microwave) is added (please refer to Appendix A).
This Standard is redrafted in accordance with ISO 589.2008 “Hard Coal -
Determination of Total Moisture”. The consistent degree between this Standard and
ISO 589.2008 is not equivalent.
This Standard was proposed by the China National Coal Association.
This Standard shall be under the jurisdiction of the National Technical Committee on
Coal Chemical Industry of Standardization Administration of China.
Drafting organization of this Standard. Coal Analysis and Test Laboratory of China
Coal Research Institute.
Chief drafting staffs of this Standard. Zhang Bo, Sun Gang and Li Hongtu.
The previous editions of the standard replaced by this Standard are as follows.
— GB 211-1963, GB 211-1984, GB/T 211-1996 and GB/T 211-2007.
Determination of Total Moisture in Coal
1 Scope
This Standard specifies the method summary, reagent and materials, apparatus,
procedures, result calculation, precision and test report for the determination of total
moisture in coal.
The method of drying under nitrogen (Method A1 and B1) shall be applicable to all
types of coals; the method of drying in air (Method A2 and B2) shall be applicable to
bitumite (excluding easily oxidized coal) and blind coal.
Method A1 shall be the arbitration method in this Standard.
Note. the method of drying by microwave that’s applicable to the rapid determination
of total moisture is also provided in this Standard. The method of drying by microwave
is applicable to bitumite and lignite. Please see Appendix A for details.
2 Normative References
The following documents are indispensable in the implementation of this Standard.
For the dated references, only the dated versions are applicable to this Standard. For
the undated references, the latest edition (including all the amendments) are
applicable to this Standard.
GB/T 212 “Proximate Analysis of Coal”
GB 474 “Method for Preparation of Coal Sample”
GB/T 19494.2 “Mechanical Sampling of Coal - Part 2. Method for Sample
Preparation”
3 Method Summary
3.1 Method A (two-stage method)
3.1.1 Method A1. drying under nitrogen
Weigh-take a certain amount of 13mm coal samples; dry them in the environment
where the temperatures do not exceed 40°C, until the constant mass is reached.
Crush the sample into particle size lower than 3mm; dry them under nitrogen at
(105~110) °C, until the constant mass is reached. Calculate the total moisture from
with a sufficiently rapid rate of atmosphere change, for instance, more than 5 times
per hour.
5.2 Nitrogen-flushed oven. with device for automatic temperature control, capable of
being controlled at (105~110)°C, able to accommodate appropriate weighing bottles
with a little more room to spare, with inlet and outlet for nitrogen, and allow more than
15 times of atmosphere change per hour.
5.3 Analytical balance. division value is 0.001g.
5.4 Industrial balance. division value is 0.1g.
5.5 Dryer. contain allochronic silica gel or granular anhydrous calcium chloride.
5.6 Flow meter. with a measuring range of (100~1000)mL/min.
5.7 Drying tower. with a volume of 250ml and contain allochronic silica gel or granular
anhydrous calcium chloride.
6 Sample
6.1 According to GB 474 or GB/T 19494.2, prepare the sample for total moisture. In
which, for 13mm coal sample for total moisture, it shall not be less than 3kg; for 6mm
sample for total moisture, it shall not be less than 1.25kg.
6.2 Before determining the total moisture in coal sample, it shall firstly check the
sealing condition of the container. Afterwards, clean the surface; weigh the sample
with an industrial balance to the nearest 0.1% of its total mass; check the result with
the total mass indicated on the label. If there’s a loss of mass and it can be
ascertained that there is no sample loss during transportation or storage, then the
mass reduced shall be regarded as that of the lost moisture. Calculate the percentage
of moisture loss and make correction in accordance with what’s mentioned in 7.3. If
the loss of mass is greater than 1.0%, then, it is not allowed to perform correction of
moisture loss; when reporting the results, it shall indicate that “the moisture loss is not
corrected” AND report the container label and sealing condition.
6.3 Before weighing-taking the sample, it shall well mix (mixing time is not less than 1
min) the sample.
7 Procedures
7.1 Method A (two-stage method)
7.1.1 Free moisture (Methods A1 and A2, drying in air)
Use a pre-dried and weighed tray to quickly take-weigh 490g~510g (accurate to 0.1g)
two continuous inspections is not more than 0.01g or the mass increases. In the latter
case, the mass of the previous inspection shall be adopted as the reference for
calculation.
7.2.2 Method B2 (drying in air)
7.2.2.1 Total moisture in 13 mm coal sample
7.2.2.1.1 Use a pre-dried and weighed tray to quickly weigh-take 490g~510g
(accurate to 0.1g) of 13 mm coal sample; spread it evenly.
7.2.2.1.2 Put the tray in an air-drying oven which has been preheated to
(105~110)°C. Under the condition of air-blowing, for bitumite, dry for 2h; for blind coal,
dry for 3h.
7.2.2.1.3 Remove the tray and weigh it (accurate to 0.1g) while it is still hot.
7.2.2.1.4 Conduct drying inspection, 30min each time, until each mass reduction in
two continuous inspections is less than 0.5g or the mass increases. In the latter case,
the mass of the previous inspection shall be adopted as the reference for calculation.
7.2.2.2 Total moisture of 6mm coal sample
Except that the nitrogen-flushed oven is replaced by the air-drying oven, the
procedures are the same as that in 7.2.1.
7.2.3 Result calculation
Total moisture in coal shall be calculated in accordance with Formula (4);
Where,
Mt — the total moisture in coal sample, %;
m — the mass of weighed coal sample, unit is gram (g);
m1 — the mass loss after the coal sample is dried, unit is gram (g).
7.3 Moisture loss correction in the sample
If there is a need for moisture correction, the value of corrected total moisture shall be
calculated in accordance with Formula (5).
......
| Standard ID | GB/T 211-2017 (GB/T211-2017) | | Description (Translated English) | Determination of total moisture in coal | | Sector / Industry | National Standard (Recommended) | | Classification of Chinese Standard | D21 | | Classification of International Standard | 73.040 | | Word Count Estimation | 10,115 | | Date of Issue | 2017-09-07 | | Date of Implementation | 2018-04-01 | | Older Standard (superseded by this standard) | GB/T 211-2007 | | Drafting Organization | Coal Science and Technology Research Institute Co., Ltd. Detection Branch | | Administrative Organization | National Coal Standardization Technical Committee (SAC / TC 42) | | Proposing organization | China Coal Industry Association | | Issuing agency(ies) | General Administration of Quality Supervision, Inspection and Quarantine of the People Republic of China, China National Standardization Administration Committee |
|