GB/T 46288-2025Maceral classification for brown coals and lignites (English PDF)

Foreword

This document complies with the provisions of GB/T 1.1-2020 "Standardization Work Guidelines Part

1.Structure and Drafting Rules of Standardization Documents". Drafting. Please note that some content in this document may involve patents. The issuing organization of this document assumes no responsibility for identifying patents. This document was proposed by the China National Coal Association. This document is under the jurisdiction of the National Coal Standardization Technical Committee (SAC/TC42). This document was drafted by: China University of Mining and Technology (Beijing), China Coal Technology & Engineering Group Xi'an Research Institute Co., Ltd., and Jiangsu Geological and Mineral Resources Design Institute. Research Institute. The main drafters of this document are. Tang Yuegang, Wang Shaoqing, Xiao Wenzhao, Zhang Qun, Zhang Guchun, and Zhu Shifei. Classification of microstructures of lignite

1 Scope

GB/T 46288-2025 is the Chinese national standard covering the microscopic constituents of lignite - the huminite group that replaces vitrinite at this rank, the liptinite and inertinite, their subdivisions and how each is recognised under the microscope, and the naming that petrographic reports use. First edition, under the China National Coal Association. In force from 1 May 2026. Issued on 5 October 2025, it has been in force since 1 May 2026.

This document specifies the classification criteria and classification scheme for the microscopic components of lignite. This document applies to lignite with a random reflectance of humus less than or equal to 0.40%.

2 Normative references

The contents of the following documents, through normative references within the text, constitute essential provisions of this document. Dated citations are not included. For references to documents, only the version corresponding to that date applies to this document; for undated references, the latest version (including all amendments) applies. This document.

GB/T 5751 Classification of Chinese Coal

GB/T 12937 Coal and Petrology Terminology

3 Terms and Definitions

The terms and definitions defined in GB/T 5751 and GB/T 12937, as well as the following terms and definitions, apply to this document.

3.1 Huminite The microscopic components of lignite, formed from the lignocellulosic tissue of plants through humification and gelation, have a reflectivity intermediate between that of the same coal. Between the darker lipid bodies and the brighter inert bodies in the sample, there is a gray micro-component.

Note. Huminite group is abbreviated as huminite group, and when emphasizing an individual, it is called huminite.

3.2 structural humus telohuminite Subgroups of septic tissue microstructure in plant cells.

3.3 wooden structure textinite A humic substance with clearly identifiable plant cell structure.

3.4 ulminite The humic body, a structure of plant cells whose structure is faintly discernible.

3.5 Detrihuminite Subgroup of humic microstructure with unidentifiable plant cell structure and particle size less than 10 µm.

3.6 attrinite Loose and porous detrital humus.

3.7 densinite Amorphous, dense detrital humus.