Coal. Bulk weight of coal

GOST R 54246-2010
(ISO 23499:2008)

Group A19

NATIONAL STANDARD OF THE RUSSIAN FEDERATION

DETERMINATION OF BULK DENSITY

Coal. Determination of bulk density

OKS 73.040
OKP 03 2000

Date of introduction - 2012-07-01

Preface

Goals and principles of standardization in Russian Federation established by Federal Law of December 27, 2002 N 184-FZ "On Technical Regulation", and the rules for the application of national standards of the Russian Federation - GOST R 1.0-2004 "Standardization in the Russian Federation. Basic provisions"

Standard information

1 PREPARED BY Federal State unitary enterprise"Institute of Fossil Fuels - Scientific and Technical Center for the Complex Processing of Solid Fossil Fuels" (FSUE "IGI") based on its own authentic translation into Russian of the standard specified in paragraph 4

2 INTRODUCED by the Technical Committee for Standardization TC 179 "Solid Mineral Fuel"

3 APPROVED AND ENTERED INTO EFFECT by Order of the Federal Agency for Technical Regulation and Metrology dated December 23, 2010 N 1045-st

4 This standard is modified from the international standard ISO 23499:2008* “Coal - Determination of bulk density” (ISO 23499:2008 “Coal - Determination of bulk density”) by changing individual phrases (words, values, references) that are highlighted in italics in the text**
________________
* Access to international and foreign documents mentioned here and further in the text can be obtained by following the link;
** In the original paper, the designations and numbers of standards and normative documents in the “Normative references” section are given in italics, the rest of the document text is in regular font. - Database manufacturer's note.

5 INTRODUCED FOR THE FIRST TIME


Information about changes to this standard is published in the annually published information index "National Standards", and the text of changes and amendments- V monthly published information indexes "National Standards". In case of revision (replacement) or cancellation of this standard, the corresponding notice will be published in the monthly published information index "National Standards". Relevant information, notices and texts are also posted in information system common use - on the official site Federal agency on technical regulation and metrology on the Internet

Introduction

Introduction

Coal as a granular mass is characterized by bulk density. This value is determined by weighing a unit volume of loosely poured coal (without compaction).

The bulk density of coal is a relative value. This is expressed in the fact that the result of the determination depends on the test conditions, the design and size of the equipment, the method of loading coal, etc.

Under the same test conditions, the bulk density of coal depends on the moisture content, the particle size distribution of the sample, and the actual and apparent density.

Depending on these factors, the bulk density of coal varies over a relatively wide range.

A standard method for determining bulk density can only be developed for a narrow range of test objects. Accordingly, this standard applies to crushed coal or coal mixtures (burden) prepared for loading into coke ovens, and establishes methods for determining bulk density in standard equipment. The design and dimensions of the cone (hopper), receiving vessel (measuring container) and the height of dropping (or falling speed) of coal from the cone into the vessel are regulated.

As required by this standard, simultaneously with determining the bulk density of coal, a sieve analysis and determination of total moisture are carried out.

Determining the bulk density of the coal charge is necessary to calculate the operation of coke ovens. It is known that the bulk density of coal loading affects physicochemical characteristics coke and the productivity of coke ovens.

1 area of ​​use

This standard applies to crushed stone coals with piece sizes less than 37 mm and establishes a method for determining the bulk density of coals or a mixture of coals (charge) prepared for loading into coke ovens. Determination of bulk density is carried out by pouring the material into a measuring container (container) without compacting efforts using a cone (hopper).

This standard is not applicable to the determination of the bulk density of finely ground or pulverized thermal coal or to the determination of the bulk density of coal stored in piles.

2 Normative references

This standard uses normative references to the following standards:

GOST R 52911-2008 (ISO 589:2003, ISO 5068-1:2007) Solid mineral fuel. Methods for determining total moisture

GOST 2093-82 Solid fuel. Sieve method for determining particle size distribution

GOST 10742-71 Brown coals, hard coals, anthracite, oil shale and coal briquettes. Methods for collecting and preparing samples for laboratory testing

GOST 17070-87 Coals. Terms and Definitions.

Note - When using this standard, it is advisable to check the validity of the reference standards in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet or according to the annually published information index "National Standards", which was published as of January 1 of the current year, and according to the corresponding monthly information index published this year. If the reference standard is replaced (changed), then when using this standard you should be guided by the replacing (changed) standard. If the reference standard is canceled without replacement, then the provision in which a reference is made to it is applied in the part that does not affect this reference.

3 Terms and definitions

This standard uses terms according to GOST 17070.

4 Essence of the method

The essence of the method is that a sample of crushed coal or charge is loaded into a cone (hopper) located at a certain height above the receiving vessel, the volume and mass of which are previously determined. After quickly opening the cone shutter, the coal enters the receiving vessel (measuring container). The surface of the coal in the vessel is leveled with a bar and the vessel with coal is weighed.

Bulk density is calculated as the ratio of the mass of freshly poured coal to its volume.

5 Equipment

5.1 The measuring vessel (receiving vessel) is a cube-shaped container with handles with a volume of (0.0284 ± 0.000082) m (1 cubic ft), with internal dimensions equal to 305 mm (1 ft). The container has a rigid structure and a smooth inner surface. The exact volume of the container (m) is determined using water of known density.

The measuring container is made of metal of such thickness as to ensure sufficient strength of the walls and bottom under experimental conditions. The minimum recommended wall thickness is 3 mm.

Note - The internal dimensions of the cube can be rounded with a permissible deviation of up to 300 mm. The volume of the container in this case will be approximately 0.027 m. It is important to know the exact volume of the measuring container, because this value is decisive when calculating the bulk density of coal.

5.2 The cone is designed for filling a measuring container with coal (see Figure 1). Cone dimensions: height 610 mm, internal diameter of the upper part 510 mm, diameter of the round hole at the bottom of the cone 115 mm. A sliding cone valve consists of a gate valve, which is a sliding plate, and a support welded to the base of the cone so that the valve can easily open and close as the valve moves along the support guides. The cone is placed in a tripod-type frame, the upper part of which is a ring with an internal diameter of 460 mm. The cone is inserted into the frame so that the distance from the top of the valve to the bottom of the measuring container is 560 mm (see Figure 1).

a) assembled device

1 - height of the cone; 2 - height from the iron valve to the bottom of the measuring container; 3 - measuring container; 4 - adjusting nut; 5 - fixing nut; 6 - M16 bolt; A- steel 1.6 mm; b- tube with outer diameter 18 mm

Figure 1 - Apparatus for determining the bulk density of coal using a cone

5.3 The leveling bar is a narrow steel strip with approximate dimensions of 760x40x5 mm.

5.4 The weighing device is a platform for weighing up to 100 kg of cargo with a permissible error limit of 0.05 kg.

6 Sample preparation

6.1 A sample of crushed coal is prepared in accordance with GOST 10742.

During sample preparation for bulk density determination, accumulated portions of the sample should be stored in a hermetically sealed container to prevent loss of moisture. The minimum sample weight for determining bulk density is 150 kg. This quantity is sufficient to perform four tests and determine the total moisture content.

6.2 A coal sample to determine bulk density is thoroughly mixed and divided, without crushing, into four portions of 34 kg each in accordance with GOST 10742. This operation is carried out as quickly as possible to prevent moisture loss and the bulk density of the coal is determined immediately. If testing cannot be performed immediately, store samples in sealed, waterproof containers with tight-fitting lids, with minimal exposure to air prior to testing.

NOTE If the sample consists of fine coal and the total moisture content changes during the test, the discrepancy between the bulk density results may be significant. The total moisture result must be representative of the sample prepared to determine the bulk density of coal (Section 6).

7 Carrying out the test

7.1 The cone, inserted into the tripod frame, is placed on a horizontal surface (on a metal plate or on the floor). The prepared sample (section 6) is placed on a flat surface and carefully leveled with a shovel or scoop so that the thickness of the coal layer is about 100 mm. Avoid pressing on the coal back side shovels or scoop. Then, successively take a shovelful or scoopful of coal from evenly distributed points on the surface of the coal and carefully pour it into the cone, approaching it from different sides. This will prevent the coal from segregating and compacting while filling the cone. About 34 kg of coal is loaded into the cone.

7.2 The center of the pre-weighed measuring cup (5.1) is located under the cone valve. Then the valve valve is fully opened, all the coal is poured into the container and poured over the edge. If the moistened coal does not flow freely from the hopper, carefully push the leveling bar (5.3) down through the coal from top to bottom.

7.3 After filling the measuring container (5.1), carefully remove excess coal while simultaneously leveling its surface by moving the leveling bar (5.3) in a horizontal plane with its support on the edges of the measuring container. At the same time, make sure that all corners of the measuring container are filled with coal. Avoid shaking or moving the filled container until all excess carbon has been removed. The measuring container is placed on the weighing platform (5.4) and weighed to an error limit of 0.05 kg. The difference in mass between filled and empty containers is the mass of uncompacted coal.

7.4 Determine the total moisture content and particle size distribution. The result of moisture determination is included in the test report. The results of sieve analysis are also included there for the correct interpretation of the bulk density value. Moisture determination is carried out by the method regulated in GOST R 52911, and sieve analysis - in accordance with GOST 2093.

8 Processing of results

Bulk density of coal , expressed in kg/m2, based on the dry state of coal, is calculated using the formula

where is the mass of a clean, dry measuring container, kg;

- mass of the filled measuring container, kg;

- volume of clean dry measuring container, m;

- total moisture of coal, %.

Bulk density of coal, expressed in kg/m, based on the working condition of coal, is calculated using the formula

Each result of determining bulk density, expressed in kg/m, is calculated with an accuracy of tenths.

The result of determining the bulk density entered into the test report is the arithmetic mean of the results of two parallel determinations, calculated to the nearest integer.

9 Precision

The precision of the method is characterized by the repeatability and reproducibility of the results obtained.

9.1 Repeatability

The results of two parallel determinations carried out in the same laboratory by the same person, using the same equipment on representative samples taken from the same test sample, should not differ from each other by more than 10.0 kg/ m.

If the results differ from each other by more than 10.0 kg/m, two additional determinations are carried out. If the second pair of results has satisfactory repeatability, then the first pair of results is discarded and the final result is calculated based on the second pair of determinations.

If the discrepancy between the results of both pairs of determinations exceeds 10.0 kg/m, then to obtain the final result, the average value of the results of four determinations is calculated, and the difference between the minimum and maximum results should be less than 13.0 kg/m. Otherwise, all results are canceled, the reason for obtaining incorrect results is clarified and eliminated, and two new determinations are made.

9.2 Reproducibility

It is impossible to determine the reproducibility of the results of determining the bulk density of coal in different laboratories, since coal may be crushed during transportation of samples. A change in the particle size distribution of the sample will lead to a change in the results of determining the bulk density of coal.

10 Test report

The test report must contain the following information:

b) sample identification;

c) test results calculated for the dry and working condition of the sample;

Electronic document text
prepared by Kodeks JSC and verified against:
official publication
M.: Standartinform, 2012

Coal deposits are formed in the bowels of the earth. This happens due to the accumulation of plant residues that are subject to decomposition and pressure from rocks. The most suitable environment for the occurrence of fossils is swampy peatland formed during shifts tectonic plate. Coal, undergoes significant chemical changes in its structure - it is enriched in carbon and loses moisture, oxygen and volatile substances. Mineral impurities of coal are represented by coal-forming agents and mineral new formations. They take the form of fine dispersion, crystals, thin layers of lenses and concretions. As a result of complex processes, a solid flammable form, black in color, is formed.

KU has a number of physical features, it:

According to the above data, weight of 1 m3 of coal, ranges from 1200 kg/m³ to 1500 kg/m³. CU is suitable for industrial use, provided >30% ash content.

Most important criterion for a given mineral is the heat of combustion. HRH is characterized by high heat transfer; the wet ashless mass emits about 23.8 MJ/kg or 5700 kcal/kg. The composition of the coal deposits depends on the place of formation of the deposits, and has a number of complex components:

Scope of application of coal.

CU is widely used in many areas of production:

Calculations of volumes and mass of coal.

Due to the extensive use of mineral resources, there is a justified need to know volumetric weight of coal. Specific coal weight are distinguished into 2 types:

For industrial purposes, to calculate the need for a fuel component, such division is extremely important.

Specific gravity of coal, has the following calculation formula:

SVKU = Weight of solids ⁄ Volume of solids

HC tends to change depending on the type of coal rock; calculations of its changes are given in the table.

DEFINITION

Coal is one of the most important natural resources located in the bowels of the earth. This is a combustible sedimentary rock of plant origin, which mainly contains carbon, as well as a number of other chemical elements(Fig. 1).

Rice. 1. Coal. Appearance.

Depending on the time of coal formation, I distinguish brown coal, hard coal and anthracite. The “older” the fossil, the higher its carbon content and the lower the concentration of volatile components, mainly water. For example, the moisture content of brown coal is 30-40%, and the content of volatile components is at the level of 50%, while for anthracite both of these parameters are in the range of 5-7%.

In addition to the above components, non-flammable ash-forming additives and sulfur can be mentioned as the fundamental components of coal. The density of coal is 1 to 1.7 g/cm 3, and this value depends not only on the type of coal, but also on the mineral content in it. In addition to the usual density for coal, the value of the so-called bulk density is often indicated. This is due to the fact that despite the fact of compaction, compaction, moistening and other “construction” operations, the density of coal still does not reach its true physical density. The bulk density of coal is 800 - 850 to 1000 kg/m 3.

Examples of problem solving

EXAMPLE 1

EXAMPLE 2

In addition to the main components, coal contains “rock”: various non-flammable ash-forming additives. The presence of breed reduces specific heat of combustion coal, increases wear on boiler mechanisms, complicates coal preparation (crushing coal to the desired fraction). Depending on the variety and mining conditions, ash content can vary greatly. Thus, the ash content of Kuzbass coal is 15-17%, brown Balakhtin coal ( Krasnoyarsk region) less than 10%, but in Russia there are coals with an ash content of up to 30-35%.
Ash is hazardous waste, polluting environment, and must be disposed of at special landfills. For ease of removal, the ash pan in Termorobot is made removable and transportable.
There are also " fly ash", which determines the environmental performance of the boiler, its quantity is taken into account when environmental assessment of the boiler house project. Dust emissions depend on the type of coal, power and boiler design.
An important indicator of coal is ash melting point, depending on the chemical composition of the rock in a particular coal, it determines the caking (slaging) of coal in the boiler furnace.

There is another harmful component of coal - sulfur. When sulfur is burned, its oxides are formed, which, interacting with water, turn into sulfuric acid. It pollutes the environment and produces acidic condensate, which destroys boiler elements. The sulfur content is usually in the range of 0.1-1%.

The main fuel indicator is specific heat combustion. The certificates indicate " higher" And " lowest"heat of combustion, their difference is described. When choosing coal and when choosing, you should pay attention to lowest heat indicated in certificates Q i r . U brown coal its value is 3000-5000, for ordinary stone coal 5000-5500 kcal/kg. In reference books you can find a value of 7000 kcal/kg, this refers to coal concentrate (“standard fuel”), such coal is not sold at ordinary coal warehouses.

Coal Density- from 1 to 1.7 t/m 3 depending on the content of mineral substances, but in practical calculations one should use " bulk density". For the Balakhta 3B coal we recommend, it is 0.8 t/m 3 (the 5 m 3 boiler room bunker of Termorobot-300 holds 4 tons of coal). The bulk density of graded hard coal is about 0.85 t/m 3.

How coal burns

At the first stage of combustion there is coal gasification: volatile substances are released from it; When there is enough oxygen, they burn quickly, producing a long flame. Then the coke residue burns out; The intensity and temperature of its combustion depends on the type of coal (brown, hard, anthracite): the higher the degree of coalification (it is the highest for anthracite), the higher the ignition temperature and heat of combustion, but the lower the combustion intensity.

Coal grades B, D, G
Because of high content volatile substances Such coal flares up quickly and burns quickly. Coal of these grades is available and suitable for almost all types of boilers, but for complete combustion this coal must be supplied in small portions so that the released volatile substances have time to completely combine with atmospheric oxygen (for example, in the Termorobot TR-200, TR-300 boilers, coal is supplied almost continuously ). Complete combustion of coal is characterized by a yellow flame and clear flue gases; incomplete combustion of volatile substances produces a purple flame and black smoke.

What do we want to learn today? How much does 1 cube of coal weigh, the weight of 1 m3 of coal? No problem, you can find out the number of kilograms or the number of tons at once, the mass (weight of one cubic meter, weight of one cube, weight of one cubic meter, weight of 1 m3) is indicated in table 1. If anyone is interested, you can skim small text Below, read some explanations. How is the amount of substance, material, liquid or gas we need measured? Except for those cases when it is possible to reduce the calculation of the required quantity to the counting of goods, products, elements in pieces (piece counting), it is easiest for us to determine the required quantity based on volume and weight (mass). IN everyday life The most common unit of volume measurement for us is 1 liter. However, the number of liters suitable for household calculations is not always an applicable method for determining the volume for economic activity. In addition, liters in our country have not become a generally accepted “production” and trade unit for measuring volume. One cubic meter, or in its abbreviated version - one cube, turned out to be a fairly convenient and popular unit of volume for practical use. We are accustomed to measuring almost all substances, liquids, materials and even gases in cubic meters. It's really convenient. After all, their costs, prices, rates, consumption rates, tariffs, supply contracts are almost always tied to cubic meters (cubes), and much less often to liters. No less important for practical activities It turns out that we know not only the volume, but also the weight (mass) of the substance occupying this volume: in this case we're talking about about how much 1 cube weighs (1 cubic meter, 1 cubic meter, 1 m3). Knowing mass and volume gives us a fairly complete idea of ​​quantity. Site visitors, when asking how much 1 cube weighs, often indicate specific units of mass in which they would like to know the answer to the question. As we noticed, most often they want to know the weight of 1 cube (1 cubic meter, 1 cubic meter, 1 m3) in kilograms (kg) or tons (t). Essentially, you need kg/m3 or t/m3. These are closely related units that define quantity. In principle, a fairly simple independent conversion of weight (mass) from tons to kilograms and vice versa is possible: from kilograms to tons. However, as practice has shown, for most site visitors a more convenient option would be to immediately find out how many kilograms 1 cubic (1 m3) of coal weighs or how many tons 1 cubic (1 m3) of coal weighs, without converting kilograms into tons or vice versa - quantities tons to kilograms per cubic meter (one cubic meter, one cubic meter, one m3). Therefore, in Table 1 we indicated how much 1 cubic meter (1 cubic meter, 1 cubic meter) weighs in kilograms (kg) and tons (t). Choose the table column that you need yourself. By the way, when we ask how much 1 cubic meter (1 m3) weighs, we mean the number of kilograms or the number of tons. However, from a physical point of view, we are interested in density or specific gravity. The mass of a unit volume or the amount of substance contained in a unit volume is bulk density or specific gravity. In this case, the bulk density and specific gravity of coal. Density and specific gravity in physics are usually measured not in kg/m3 or tons/m3, but in grams per cubic centimeter: g/cm3. Therefore, in Table 1, specific gravity and density (synonyms) are indicated in grams per cubic centimeter (g/cm3)