⛽ Moisture content — SIMPLIFIED methods for coal, coke and char (PN-G-04611)

Petrochemistry and fuels PN-G-04611

Overview

THE WORD "SIMPLIFIED" IS PART OF THE TITLE AND THE MOST IMPORTANT INFORMATION IN THIS ENTRY. The title on the PKN catalogue card reads: "Węgiel kamienny, koks i półkoks z węgla kamiennego oraz karbonizat -- Oznaczanie zawartości wilgoci -- Metody uproszczone" [Hard coal, coke and semi-coke from hard coal and char — Determination of moisture content — Simplified methods]. The scope quoted from the card: "W niniejszej normie przedstawiono uproszczone metody oznaczania zawartości wilgoci przemijającej w węglu kamiennym, zawartości wilgoci w próbce analitycznej węgla kamiennego, koksu i półkoksu z węgla kamiennego oraz karbonizacie, zawartości wilgoci całkowitej w węglu kamiennym, koksie i półkoksie z węgla kamiennego oraz karbonizacie" [This standard presents simplified methods for determining the free moisture content of hard coal, the moisture content in the analysis sample of hard coal, coke and semi-coke from hard coal and char, and the total moisture content of hard coal, coke and semi-coke from hard coal and char]. That is, the same measured quantity as in PN-G-04511 and PN-ISO 589, but a different procedure — simplified compared with the basic methods. WHAT EXACTLY THE SIMPLIFICATION CONSISTS OF AND HOW IT AFFECTS THE RESULT, WE HAVE NOT ESTABLISHED: we did not have the text of the standard (18 pages, available for a fee).

STATUS AND A SUBJECT SCOPE WIDER THAN THAT OF ITS NEIGHBOURS. The PKN card (reading of 22.09.2026): publication 01-06-2020, 18 pages, Mining Sector, Technical Body KT 220, ICS 75.160.10; NO "Wycofana" [Withdrawn] header and no "Data wycofania" [withdrawal date] row — the standard is current. The card also has NO "Zastępuje" [Replaces] field: this standard did not replace anything, it was added alongside. The materials covered are hard coal, coke and semi-coke from hard coal AND CHAR — the scope of PN-G-04511 does not mention the latter.

HOW IT GOT INTO THE PROVISION AND SINCE WHEN. The Regulation of the Minister of Climate and Environment of 7 December 2023 (Journal of Laws 2023 item 2661) amended item 8 of the annex to the regulation on methods of testing the quality of solid fuels: the words "PN-G-04511:1980 albo PN-ISO 589:2006" were replaced by the words "PN-G-04511:1980, PN-ISO 589:2006 albo PN-G-04611:2020" [albo = or]. The amendment entered into force on 9 December 2023. THIS MEANS THAT THE LEGISLATOR ADDED THIS STANDARD ALONGSIDE THE OTHER TWO, NOT IN THEIR PLACE — and did so in the act by which it opened this item, having the possibility of removing the standard withdrawn since 2012. It did not remove it.

THE EQUIVALENCE IS LEGAL, NOT TECHNICAL — AND THAT IS THE MOST IMPORTANT DISTINCTION FOR THE READER. The provision permits each of the three bases for determining total moisture, so from the point of view of legal compliance the choice is free. The documents are not the same, however: the other two describe basic methods, and this one — simplified ones. A laboratory choosing this standard should be able to say why the simplification is acceptable in its case; the entry does not decide this, because it does not have the text of any of the three standards.

DO LABORATORIES USE IT INTERCHANGEABLY — A MEASUREMENT. Our own measurement on the database of accreditation scopes (22-09-2026, 17 h): PN-G-04611 appears in 88 entries in 23 laboratories; this standard only, without the other two — 57 entries in 19 laboratories; together with PN-G-04511 — 20 entries; together with PN-ISO 589 — 7; all three at once — 4. The most frequent methodologies: moisture content in the analysis sample (23), total moisture content (20), free moisture content (11), total moisture content, calculated (10). The matrix in 49 entries is "Paliwa stałe: węgiel kamienny" [solid fuels: hard coal]. THE DISTRIBUTION OF METHODOLOGIES IS THE SAME AS WITH THE OTHER TWO STANDARDS — a picture of an alternative, not of a division of activities between documents.

FORM OF THE NUMBER: THREE SOURCES, THREE NOTATIONS — AND HERE THE ACT IS LESS PRECISE THAN THE LABORATORIES. The catalogue card gives "PN-G-04611:2020-06". Accreditation scopes use exactly this form: 80 entries out of 88. The regulation writes "PN-G-04611:2020" — without the month element. This is the opposite direction from PN-G-04511, where the act gives the form from the card ("PN-G-04511:1980") and the scopes the old scheme ("PN-80/G-04511"). THERE IS THEREFORE NO RULE THAT THE ACT WRITES STANDARDS MORE CAREFULLY OR LESS CAREFULLY THAN THE LABORATORIES — the discrepancy goes both ways and must be checked separately for each standard. In one scope entry there is also a typo "PN-G-04611:2020-0606"; we mention this not as a curiosity, but because a search by the exact number will not find such an entry.

WHAT WE DO NOT GIVE. We did not have the text of the standard. WE DO NOT GIVE: what the simplification compared with the basic methods consists of, drying temperatures and times, requirements for the apparatus, the method of calculating total moisture or the precision of the method — and it is precisely the precision that would decide whether the results are comparable with PN-G-04511 and PN-ISO 589. Nor have we checked whether ISO has published a newer version of a source document; the standard is national, and the card does not indicate an implemented document.

Method principle

The sample is dried under the conditions given in the standard and weighed; the loss of mass gives the moisture content. The standard describes simplified variants for determining three quantities: free moisture, moisture in the analysis sample and total moisture — the latter also by calculation from the previous two. We do not quote the procedures themselves, because we did not have the text of the standard.

Applications

• Determination of total moisture content in testing the quality of solid fuels — as one of the three bases permitted by item 8 of the annex to the regulation (since 9 December 2023)
• Testing of char, which is not covered by the scope of PN-G-04511
• Recognising the citation "PN-G-04611:2020-06" in an accreditation scope and checking whether the laboratory applies the basic or the simplified method
• Assessment of older documentation: before 9 December 2023 this standard was not indicated by the provision

Key parameters

Standard

Standard number

PN-G-04611:2020-06 (wersja polska)

Title (PL)

Węgiel kamienny, koks i półkoks z węgla kamiennego oraz karbonizat — Oznaczanie zawartości wilgoci — Metody uproszczone

Title (EN)

Hard coal, coke and semi-coke from hard coal and carbonizate — Determination of moisture content — Simplified methods

Step-by-step procedure

1. Checking whether the simplified method is permissible in the given test

   When testing the quality of solid fuels placed on the market, item 8 of the annex permits this standard since 9 December 2023 on an equal footing with PN-G-04511:1980 and PN-ISO 589:2006. For tests performed on another basis (a contract, a customer's specification), it must be checked whether the client accepts the simplified method.

2. Sampling and securing the sample

   Place the sample in an airtight container and limit the time until the first weighing. Water lost at this stage makes the result too low, while the subsequent operations proceed correctly — the error leaves no trace.

3. Choice of the quantity to be determined

   The standard covers three: free moisture, moisture in the analysis sample and total moisture. The report must state which, because they are not interchangeable and have different uses.

4. Drying and weighing according to the simplified variant

   The conditions (temperature, time, form of the sample) are specified by the text of the standard and we do not quote them. Materials covered: hard coal, coke, semi-coke and char.

5. Calculation of total moisture, if determined in two stages

   Total moisture arises from free moisture and moisture in the analysis sample. We do not quote the formula. The result is a CALCULATED quantity — a change in the methodology of either component changes it without any change in the formula.

6. Recording the result with the basis and the type of method stated

   In the report, give the full designation ("PN-G-04611:2020-06"), the type of moisture determined and the fact that a SIMPLIFIED method was applied — otherwise the recipient of the result will not distinguish it from the basic method according to the other two standards.

Required equipment and apparatus

Reagents, media and consumables

Health and safety (OHS)

• Coal dust is combustible and explosive as a suspension — limit dusting during sample preparation
• The sample removed from the oven is hot
• Char and coke produce finer dust than raw coal — use extraction when pouring

Frequently asked questions