Decree No. 5 / 1994 Coll.
Order of the Czech Mining Authority laying down the method of sampling and analysis of samples of inert and coal dust and mixtures of inert and coal dust in coal mines
Valid
Effective from 18.01.1994
Contents
5
DECLARATION
Czech Mining Office
of 6 December 1993
laying down the method of sampling and analysis of inert and coal dust samples and mixtures of inert and coal dust in coal mines
According to § 6 paragraph 6 (a) of the Act of the Czech National Council No. 61 / 1988 Coll., on Mining Activities, Explosives and State Mining Administration, as amended by the Act of the Czech National Council No. 425 / 1991 Coll., Act of the Czech National Council No. 542 / 1991 Coll. and Act No. 169 / 1993 Coll.:
INTRODUCTORY PROVISIONS
Scope
This Decree sets out the conditions for sampling inert and coal dust and mixtures of inert and coal dust (hereinafter referred to as dust mixture) and their analysis in coal mines.
Interpretation of terms
(1) Inert dust is limestone or other dust intended for the disposal of settled coal dust in the mine.
(2) Dust is the spraying of inert dust in the mine to inert settled coal dust.
(3) The inertization of coal dust is to prevent the ability of coal dust contained in the mine to explode and transmit the explosion during ignition and ignition.
INERT DRIVER
Sampling of inert dust
(1) Sampling of inert dust is carried out by the manufacturer to determine its properties. 1)
(2) All sampling methods shall be carried out in such a way that the sum of incremental samples represents the average of all product quality indicators.
(3) For technological tests and chemical analysis, the sample shall have at least 3 kg mass.
(4) The data on sampling and the results of the tests and analyses must be documented with the manufacturer together with a quality certificate for the product.
(5) The collector shall carry out tests where he has doubts about the properties of the inert dust supplied.
Analysis of inert dust samples
(1) The analysis of inert dust must be carried out according to the methodology (1) approved by the Czech Mining Authority.
(2) The analysis of inert dust shall determine:
(a) granulometric composition,
(b) hygroscopic,
(c) curvature;
(d) free silica, the presence of fibroplastic and toxic substances and the content of flammable components.
_
Sampling of coal dust
(1) In order to determine the intensity of the deposition of coal dust, the organisation2) must carry out sampling after the source point of its formation in the direction of wind flow.
(2) Samples shall be taken from horizontal shelves or samples. The shelves and samples are placed along the walls of the mine in the lower third of the section. The shelves consist of two to four straight and on the surface of smooth plates.
(3) Samples may be plastic bags suspended in frames with a pre-determined weight and a standard hole area. At the end of the measurement, the samples shall be closed and their mass determined to the nearest 0,1 g.
(4) On shelves, the coal dust placed on the shelves shall be swept with a hairbrush into the sample panel and weighing it to the nearest 0,1 g. The time of measurement shall be determined in such a way that the mass of the sample taken is not less than 2 g. The measurement period shall be set at least for one day.
(5) The sampling shall be recorded in accordance with Annex 1, which is part of this Order.
Intensity of coal dust installation
For the sample taken and weighed, the density of the coal dust shall be calculated according to the relation:
Ip = 4.35. b. mS. S1. t
Ip - Intensity of coal dust in g.m-3.d-1
b - bright width of the mine work on the beginning in m
m - mass of sample taken in g
S - area of light section of the work in m2
S1 - area of shelves or holes of samples in m2
t - the time of settling coal dust in days.
COLLECTION AND DISTRIBUTION OF THE SAMPLES OF PRE-ORDER
Time limit for sampling of dust mixture
According to the determination of the density of coal dust, the sampling period for dust mixture shall be calculated from the relation:
T = k. SMVIp
T - time limit for sampling of dust mixture in days
k - coefficient dependent on methane content in air to be determined according to the table:
| Koncetrace CH4 v obj.% | 0,5 | 0,75 | 1,0 | 1,5 | 2,0 |
| k | 0,75 | 0,6 | 0,5 | 0,35 | 0,25 |
SMV - the lower limit of the explosives collected by the settled coal dust is 600 g / m3, unless a different value is determined by an organisation designated by the Czech Mining Authority.
Where the calculated time limit for sampling of a dust mixture is shorter than those laid down in the Regulation, 3) sampling of the dust mixture shall be carried out within the calculated time limit and measures shall be taken to reduce the establishment of coal dust.
Sampling of dust mixture
(1) A sample of the dust mixture is taken:
(a) in a continuous belt of a mine,
(b) from different places of the mining work.
(2) The sampling of the dust mixture shall be carried out by personnel designated by or authorised by the factory mine.
(3) For the sampling of a powder mixture in a continuous belt, a belt of a width of about 50 cm extending to the whole number, both sides and, where appropriate, the ceiling, shall be defined on the circumference of the work, provided that there is a greater degree of coal dust on it. The sample of the mixture shall be taken from the reinforcement and equipment of the corridor and from the number, the width of the belt being chosen so that the weight of the sample is at least 100 g after its treatment.
(4) When sampling from different places of the mine, at least 10 sampling points shall be selected on a section of a long work of between 5 and 15 m, with half being on the sides and ceiling of the work and half being on its number.
(5) A flat hairbrush shall be used to collect only the upper part of the layer of dust placed on the sample panel, not more than 5 mm thick.
(6) The sampling form shall bear a permanent number and a mine marking.
(7) After collection, the sample list shall be sealed tight and an entry drawn up in accordance with Annex 2, which is part of this Order. The record shall be made three times, one of which shall be kept by the racing mine or by its authorised staff and the other two shall be transmitted to the laboratory together with the sample.
(8) The sample of dust mixture collected shall be submitted to the laboratory for analysis no later than the following day after collection.
Analysis of dust mixture samples
(1) In the laboratory, the sample shall be sifted with a mesh size of 1,0 mm and the excess sieve removed. A sieve weighing not less than 100 g shall consist of a laboratory sample.
(2) The analysis of samples of a dust mixture determines the content of flammable substances.
(3) Analysis of samples of dust mixture must be carried out no later than two days after delivery to the laboratory.
(4) The detection of more flammable components in the sample than is permitted, (4) shall be notified immediately to the head of the laboratory to the factory mine or to the worker authorised by it, who shall immediately ensure the removal of the non-compliant condition and to order measures to avoid recurrence of that condition.
(5) The result of the analysis of the determination of flammable components shall be recorded by the laboratory on the record which has been transmitted to it with the sample and, after signature by the head of the laboratory, shall transmit that record to the factory mine or to the worker authorised by it.
Methods of analysis of dust mixture
(1) Analysis of dust mixture samples shall be carried out:
(a) the exact weighting method;
(b) the simplified weighting method.
(2) The exact weighting method shall be determined in the sample:
(a) Wa water content by weight;
(b) ash Aa content by weight,
(c) the CO2a carbon dioxide content by weight.
The content of flammable components in% by weight shall be calculated by reference to:
Oh = 100-Wa + Aa + CO2a
(3) Simplified dragonfly methods may only be used to check dust efficiency with inert dust. The content of flammable components shall be determined from at least two batches of the same sample and calculated according to the relation:
Oh = m1-m2m1.100
Oh - content of flammable components in% weight
m1 - weight of sample weight in g
m2 - weight of the rest of the sample weight after annealing in g.
Accuracy of determination of the content of flammable components
(1) In the case of two parallel determinations of the content of flammable components of the same sample, the exact weighting method shall allow a difference between the results of not more than 0,25%; if the difference is not exceeded, the final result shall be the arithmetic mean of the two parallel determinations.
(2) In the case of two parallel determinations of the contents of the flammable components of the same sample by a simplified weighting method, the difference between the results shall not exceed 1%; if the difference is not exceeded, the final result shall be the arithmetic mean of the two parallel determinations.
(3) If the difference in the determination of the flammable component content is greater than those referred to in paragraphs 1 and 2, further determination shall be made and the result shall be taken to be the arithmetic mean of the two nearest values within the tolerance range. If the value of the third determination is within the range of the permissible difference for each of the two determinations, the arithmetic mean of the three determinations shall be considered the result of the test.
Records
The sampling and analysis of samples of coal dust and dust mixtures shall be recorded in accordance with the models set out in Annexes 1 and 2 to this Decree.
FINAL PROVISIONS
Efficacy
This decree shall take effect on the day of its publication.
Chairman:
Ing. Bartoš v. r.
Příloha č. 1
Annex No 1
Record of sampling of coal dust
| Datum | Číslo vzorku | Místo odběru | Staničení | Poznámka |
| Světlá šířka díla v m | ||||
| Hmotnost odebraného vzorku v g | ||||
| Plocha světlého průřezu díla v m2 | ||||
| Plocha polic nebo otvorů vzorkovnic v m2 | ||||
| Doba usazování uhelného prachu ve dnech | ||||
| Vypočtená intenzita usazování uhel. prachu | ||||
| Vypočtená lhůta pro odběr vzorků prach. směsi | ||||
| Podpis vzorkaře: | Podpis pracovníka organizace: | |||
Příloha č. 2
Annex No 2
Record of dust mixture sampling
| Datum | Číslo vzorku | Místo odběru | Staničení | Hořlavé součásti v % | Poznámka |
| Podpis vzorkaře: | |||||
| Datum předání k rozboru: | |||||
| Datum provedení rozboru v laboratoři: | |||||
| Datum předání výsledku rozboru: | |||||
| Metoda rozboru vzorku: | Podpis vedoucího laboratoře: | ||||
1) § 157 of the ČBÚ Decree No. 22 / 1989 Coll., on safety and health at work and safety at operation in mining and mining activities in underground.
2) § 5a of Act No. 44 / 1988 Coll., on the Protection and Use of Mineral Wealth (Mining Act), as amended by Act No. 541 / 1991 Coll.
3) § 155 of Decree No. 22 / 1989 Coll.
4) § 154 of Decree No. 22 / 1989 Coll.
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Regulation Information
| Citation | Decree of the Czech Mining Office No. 5 / 1994 Coll., laying down the method of sampling and analysis of samples of inert and coal dust and mixtures of inert and coal dust in coal mines |
|---|---|
| Regulation Type | - |
| Author | - |
| Collection | Code of Laws |
| Date of Promulgation | 18.01.1994 |
|---|---|
| Effective from | 18.01.1994 |
| Effective until | - |
| Status | Valid |
The regulation text is for informational purposes only.
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