Recently, the official website of the Liaocheng Municipal Market Supervision Administration in Shandong Province published the results of the 2025 municipal-level supervision and random inspection for coal product quality.
The inspection was organized and carried out in accordance with laws and regulations such as the "Product Quality Law of the People's Republic of China" and the "Interim Measures for the Administration of Product Quality Supervision and Sampling," as well as the city's product quality supervision sampling plan and implementation rules.
The sampling inspected honeycomb briquette products for items including calorific value (Qgr,d), total sulfur (St,d), volatile matter (Vd), cold crushing strength (SCC), phosphorus content (Pd), chlorine content (Cld), arsenic content (Asd), mercury content (Hgd), and fluorine content (Fd), based on the GB 34170-2017 "Quality of Commercial Coal - Civil Briquette" standard and the "Liaocheng City Coal Product Quality Supervision and Sampling Implementation Rules" (2024).
For other types of briquettes, inspections covered calorific value (Qgr,d), total sulfur (St,d), volatile matter (Vd), cold crushing strength (SCC), shatter strength, undersize rate for 25mm aperture (b), phosphorus content (Pd), chlorine content (Cld), arsenic content (Asd), mercury content (Hgd), and fluorine content (Fd).
A total of 26 batches of coal products were sampled and inspected, all of which passed the tests.
A list of enterprises from which samples were not obtained was also provided.
Coal products are civil coal processed into shape using appropriate techniques and equipment, including honeycomb briquettes and other formed briquettes.
When selecting and purchasing, it is recommended that qualified coal products should exhibit a physical form characterized by being "regular, uniform, and free of obvious defects."
They should appear predominantly jet-black and shiny with uniform gloss, lacking grayish, dull, or mottled marks; shaped products like honeycomb briquettes should be consistently regular in shape without significant deformation, missing corners, or cracks.
Qualified formed briquettes should show no significant shedding of residue or powder, featuring a smooth, compact surface without issues like looseness or crumbling corners.
Gently tap a lump of coal by hand or strike two pieces together; qualified products have moderate hardness, producing a clear, crisp sound upon impact and are not easily crushed into powder.
To judge moisture content, pinch the surface or fragments of the coal product; qualified products have moderate moisture, feeling dry to the touch without being sticky, and leave no obvious water mark after finger pressure.