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This standard is developed in accordance with the rules given in GB/T 1.1-2009.
This standard was proposed by the China National Coal Association.
This Standard is under the jurisdiction of the National Technical Committee on Coal Standardization Administration of China (SAC/TC 42).
General Rules for Testing Methods of Coal Preparation
1 Scope
This standard specifies the relevant terms and definitions, symbols, test coal samples, dense preparation, expression of results, test records and test reports for the testing methods of coal preparation.
This standard is applicable to various standards, specifications, reports, books, textbooks and manuals concerning the testing methods of coal preparation.
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 474 Method for Preparation of Coal Sample
GB/T 475 Method for Manual Sampling of Commercial Coal
GB/T 483 General Rules for Analytical and Testing Methods of Coal
GB/T 3715-2007 Terms Relating to Properties and Analysis of Coal
GB/T 7186-2008 Terms Relating to Coal Preparation
GB/T 8170 Rules of Rounding Off for Numerical Values & Expression and Judgment of Limiting Values
GB/T 19494.1 Mechanical Sampling of Coal—Part 1:Method for Sampling
GB/T 19494.2 Mechanical Sampling of Coal—Part 2:Method for Sample Preparation
3 Terms and Definitions
For the purpose of this standard, the terms and definitions specified in GB/T 3715-2007 and GB/T 7186-2008 as well as the following ones apply. For the convenience of application, some terms and definitions in GB/T 3715-2007 and GB/T 7186-2008 are listed again.
3.1
coal sample
representative portion of coal taken from coal to determine certain characteristics
[GB/T 3715-2007, Definition 3.1.1]
3.2
sampling
process that a representative portion of coal is taken from a large amount of coal
[GB/T 3715-2007, Definition 3.1.2]
3.3
increment
portion of sample taken by the sampler operating once or cutting a full cross-section of the coal flow
[GB/T 3715-2007, Definition 3.1.10]
3.4
gross sample
coal sample of all increments taken from one sampling unit
[GB/T 3715-2007, Definition 3.1.11]
3.5
coal sample for production
under normal production conditions, coal sample taken during a full-scale coal mining process that represents the physical, chemical, and process characteristics of the coal produced
[GB/T 3715-2007, Definition 3.1.17]
3.6
bulk density
mass of bulk coal per unit volume under specified conditions
[GB/T 3715-2007, Definition 3.2.26]
3.7
size analysis
test that the coal sample was divided into groups of different particle sizes using sieves of different pore sizes and then subjected to the measurement of the particle size characteristics
[GB/T 7186-2008, Definition 4.1.3]
3.8
dense
liquid or solution with a density greater than that of water for use in coal float-and-sink tests. Dense is divided into organic dense, zinc chloride dense and inorganic high-density dense.
[GB/T 7186-2008, Definition 5.4.1]
3.9
float-and-sink analysis; float-and-sink test
coal samples are separated into different density levels by the dense of different densities.
[GB/T 7186-2008, Definition 3.2.2]
3.10
test coal’s degradation in water
test that coal or its associated minerals were added with water in the rotary bucket for overturn of different duration, for the purpose of measuring recrushing degree, including the coal’s degradation test in water in rotary bucket and degradation degree measurement for associated minerals of coal.
3.11
the ratio of degradation in water
ratio of the mass of fine slime less than 10 μm to the total mass of the 0.5 mm undersize, in the degradation measurement results
3.12
flotation test
test to determine the floatability and flotation process conditions of pulverized coal (slime).
3.13
batch-flotation test
flotation test carried out using a single tank flotation machine
[GB/T 7186-2008, Definition 5.6.40]
3.14
timed-release analysis
batch-flotation test using one roughing and multiple cleaning
[GB/T 7186-2008, Definition 5.6.41]
3.15
natural falling test
discrete falling test on a slime water sample without any flocculant or coagulant
3.16
flocculant performance test
test that flocculant of different mass is added to the slime water to measure the free falling speed and the initial falling speed of the flocs to reflect the flocculant falling performance
3.17
determination of content of magnetic material
operation process of measuring the content of magnetic material in the magnetite powder for coal preparation by a magnetic material analyzer
3.18
slime pressure filtration test
pressure filtration test carried out with a pressure filter in order to determine the process parameters affecting the slime pressure filtration effect and to study the slime pressure filtration characteristics
3.19
determination of filter aiding effect of flocculants
operation process of measuring the filter aiding effect of flocculants by a laboratory-use vacuum filtration system
3.20
determination of angle
operation process of measuring the angle of repose of coal sample of certain particle size
3.21
determination of percentage of refuse content
operation process of measuring the refuse content of coal samples
3.22
determination of undersize fraction
operation process of measuring the undersize fraction of coal samples
3.23
error
difference between the observed value and the acceptable reference value
3.24
accuracy
degree of closeness between the observed value and the true value or the agreed true value
3.25
precision
degree of compliance between the independent test results obtained under specified conditions
3.26
tolerance
maximum allowable difference between two or more observed values obtained under specified conditions
3.27
repeatability
certain value. critical value of the difference (at 95% probability) between the results obtained during the repeated measurements carried out in the short term under repeated conditions, i.e. by the same operator, with the same instrument, on the same sample, in the same laboratory
4 Coal Samples
4.1 Sampling and preparation
In accordance with GB/T 474, GB/T 475, GB/T 19494.1 and GB/T 19494.2.
4.2 Storage of coal samples
The moisture samples shall be placed in a closed container. After the test samples are air-dried, they are sealed and stored in a water-proof sample bag.
4.3 Sampling for analysis test
The coal sample shall be thoroughly mixed before sampling and sampled from several points.
5 Preparation of Dense
5.1 Commonly-used dense
The dense commonly used in the experiment is inorganic dense and organic dense. The inorganic dense is high-density dense and zinc chloride solution, while the organic dense is prepared with carbon tetrachloride and benzene or with carbon tetrachloride and bromoform.
5.2 Preparation of dense
The inorganic high-density dense is prepared by a dilution method, and the diluted dense can be concentrated by evaporation to increase the density. Zinc chloride and organic dense can be prepared with reference to Table 1.
Foreword i
1 Scope
2 Normative References
3 Terms and Definitions
4 Coal Samples
5 Preparation of Dense
6 Expression of Results
7 Test Records and Test Reports
