🔥 Sampling and preparation of samples of hard coal and brown coal — PN-G-04502

Petrochemistry PN-G-04502

Overview

SCOPE FROM THE PKN CARD, IN FULL: "W niniejszej normie określono metody podstawowe pobierania i przygotowania próbek do badań laboratoryjnych z sortymentów węgla kamiennego i węgla brunatnego oraz wyznaczania uzyskanej precyzji pobierania, przygotowania i analizy próbek." [This standard specifies the basic methods of sampling and of preparing samples for laboratory testing from size grades of hard coal and brown coal, and of determining the precision achieved in sampling, preparation and analysis of samples.]

STATUS AND ORIGIN (state of the PKN cards on 25.09.2026). PN-G-04502:2014-11 — Polish-language version, publication 14-11-2014, 22 pages, KT 220 for Natural Solid Fuels, Mining Sector, ICS 73.040; replaces PN-G-04502:1990; the card has no "Wycofana" [Withdrawn] header and NO "Wprowadza" [Implements] field — this is a purely national standard, not a translation of an ISO standard. The previous edition of 1990 (withdrawn 14-11-2014) was, according to its card, equivalent to ISO 1988:1975 [EQV] and described the taking of primary increments from belt conveyors, wagons, mine cars and ships, the size of the gross sample depending on the size of the lot and on the particle size, and the preparation of analysis samples separately for hard coal and brown coal.

THE STANDARD IN A REGULATION — WHAT FOLLOWS FROM IT LEGALLY. The Regulation of the Minister of Energy of 27 September 2018 on the method of sampling solid fuels (Journal of Laws 2018 item 1891, in force; amended by the regulation of the Minister of Climate and Environment of 7 December 2023, Journal of Laws 2023 item 2662) designates PN-G-04502:2014-11 for solid fuels other than products of the thermal processing of coal. The annex to the regulation shows which clauses of the standard are responsible for what: • clause 5.3 — the method of taking primary increments; • clause 5.1 — the formula for the minimum mass of a primary increment (the formula uses the upper particle size of the size grade from the table in the regulation, e.g. nuts 80 mm, peas 40 mm, eco-peas and eco-fines 31.5 mm, lumps and cobbles 200 mm); • clause 5.2.1 or the formula from clause 5.2.2 — the minimum number of primary increments from a lot; • Clause 7, including Table 3 in clause 7.1 — equipment for preparing the laboratory sample, crushing, mixing, dividing and the minimum mass of the sample after division. For particle sizes other than those in Table 3, the regulation gives its own formula: y = 0.05 + 0.5x + 0.05x², where y is the mass of the sample after division in kg, and x — the largest particle after crushing in mm. Sampling locations listed in the regulation: belt conveyors (stopped, transfer point of a moving conveyor, moving conveyor), bucket elevators, railway wagons and heaps after unloading them, trucks and heaps after unloading, ships and barges, stockpiles. THE SECOND STANDARD IN THE SAME REGULATION — WITHDRAWN: for fuels from the thermal processing of coal (coke) the regulation designates PN-ISO 18283:2008. The PKN card of this standard has the "Wycofana" [Withdrawn] header and the withdrawal date 20-11-2024, without a "Zastąpiona przez" [Replaced by] row; the catalogue contains PN-ISO 18283:2025-07 in the English-language version (implements ISO 18283:2022). The wording of the regulation after the 2023 amendment still lists the 2008 edition.

HOW ACCREDITATION SCOPES CITE THE STANDARD — BY CLAUSES. Measurement of 25.09.2026 on the database of PL accreditation scopes (1310 laboratories with entries): 35 entries at 19 laboratories and as many as 32 different notations — almost every laboratory lists its own set of clauses, e.g. "pkt 5.3.1.2; 5.3.1.3; 5.3.1.4; 5.3.3; 5.3.4; 5.3.6", "pkt. 5.3.1.3", "p. 5.3.6", "pkt 5.1, pkt 5.2, pkt 5.3.1.2, pkt 8", "pkt. 10", "z wył. pkt. 5.3.2, 5.3.5" [pkt, p. = clause; z wył. pkt. = excluding clause]. The listed clauses are subclauses of clause 5.3, which the regulation calls the "method of taking primary increments" — that is, each laboratory is accredited for a DIFFERENT set of locations or methods of sampling. Which subclause 5.3.x corresponds to which location does not follow from the notations, and we do not have the text of the standard — therefore we DO NOT GIVE this assignment. Object: "Paliwa stałe: węgiel kamienny" [solid fuels: hard coal] (20 and variants), in single entries also brown coal and coke. Methodology: "Pobieranie próbek do badań chemicznych i fizycznych" [sampling for chemical and physical testing] (24), "Pobieranie i przygotowanie próbek do badań fizycznych i chemicznych" [sampling and preparation of samples for physical and chemical testing] (2). In two entries PN-ISO 18283:2008 stands alongside — a standard withdrawn on 20-11-2024.

THE KEY OF THE "LABORATORIES" TAB: "PN-G-04502" — 18 laboratories and 34 entries, without any foreign entries; it will not show one laboratory (AB 883) with the notation "PN G-04502:2014-11" without a hyphen.

WHAT WE DO NOT GIVE. We did not have the text of the standard — PKN makes it available for a fee. We DO NOT GIVE the formulas for the mass and number of primary increments, the methods of sampling at individual locations, Table 3 with the sample masses or the method of determining precision. The numbers in this entry come from the regulation, not from the standard.

Method principle

From a lot of coal, many primary increments are taken at specified locations (conveyors, wagons, trucks, ships, stockpiles), each with a mass at least as large as follows from the upper particle size, in a number depending on the lot. All of them are combined into a gross sample, which — according to the regulation — is divided into a test sample and a reference sample, and then crushed, mixed and divided down to the laboratory sample and the analysis sample. The standard also gives a method of determining the precision of sampling, preparation and analysis. We DO NOT GIVE the formulas and masses — we did not have the text of the standard.

Applications

• Sampling of hard coal and brown coal for quality testing — calorific value, ash, sulphur, moisture
• Quality control of solid fuels placed on the market — the regulation on the method of sampling solid fuels
• Acceptance of coal deliveries from conveyors, wagons, trucks, ships and stockpiles
• Determining the precision of the sampling — preparation — analysis chain

Key parameters

Standard

Standard number

PN-G-04502:2014-11 (wersja polska)

Title (PL)

Węgiel kamienny i brunatny — Pobieranie i przygotowanie próbek do badań laboratoryjnych — Metody podstawowe

Step-by-step procedure

1. Establishing the lot and the size grade

   Upper particle size of the size grade from the table in the regulation — for the formula for the minimum mass of a primary increment (clause 5.1 of the standard).

2. Number and mass of primary increments

   According to clause 5.2.1 or the formula from clause 5.2.2 (number) and the formula from clause 5.1 (mass). WE DO NOT GIVE the formulas.

3. Sampling

   At the location indicated in the accreditation scope (subclauses 5.3.x) — conveyor, wagon, truck, ship, stockpile.

4. Gross sample

   Combining all primary increments from the lot; according to the regulation, division into a test sample and a reference sample in a 1:1 ratio and packing at the sampling location.

5. Laboratory sample and analysis sample

   Crushing, mixing and dividing according to Clause 7 of the standard down to the masses from Table 3 (for other particle sizes — the formula from the regulation).

6. Report

   State the edition of the standard and the clauses according to which sampling was done — without them it is not known which method of sampling was applied.

Required equipment and apparatus

Health and safety (OHS)

• Sampling from conveyors — only from a stopped conveyor or from places intended for sampling during operation; protection against being drawn in
• Work on wagons, ships and stockpiles — protection against falls and slides of material
• Coal dust — respiratory protection; risk of spontaneous combustion of stockpiles

Frequently asked questions