▎ 摘　　要

NOVELTY - Upgrading (M1) coal, comprises: cleaning coal to form a cleaned coal residue; and at least one of reacting the cleaned coal residue with an oxidizable inorganic metallic agent, and reacting the cleaned coal residue with a reducing agent, to form the upgraded coal. USE - The methods are useful for upgrading coal which is used in graphene film or a graphene quantum dot (claimed). ADVANTAGE - The methods provides upgraded coal that: has an ash content of 4-15 wt.% lower than an ash content of the coal prior to the cleaning and of less than 5 wt.% or 1-50% less oxygen concentration than the coal prior to the cleaning and/or 1-30% higher carbon concentration than the coal prior to the cleaning; has a lower volatile matter (VM) content than other lignite coals, e.g. VM of 13-19% lower relative to the starting naturally-sourced coal, and a sulfur content that is lower than the sulfur content in the starting raw coal, e.g. 4% lower or more; can be converted to energy with greater efficiency (e.g. higher energy density) and with less production of ash; and can be converted to graphene films and/or graphene quantum dots more efficiently and/or with a higher quality of product than other coals. DETAILED DESCRIPTION - INDEPENDENT CLAIMS are also included for: (a) a graphene film formed by the method (M1); (b) upgrading (M2) coal, comprising cleaning coal having a largest dimension of less than or equal to25 mm using a strong mineral acid at a temperature of 30-100degrees Celsius to form a cleaned coal residue and at least one of reacting the cleaned coal residue at 100-500degrees Celsius under an inert gas with an oxidizable inorganic metallic agent comprising iron(II) sulfate heptahydrate and/or iron(II) chloride tetrahydrate and reacting the cleaned coal residue at 0-50degrees Celsius in an organic solvent with a reducing agent comprising lithium aluminum hydride and/or sodium borohydride to form the upgraded coal, where the upgraded coal has a lower ash content, as compared to the coal used to form the upgraded coal, and the upgraded coal has at least one of a lower oxygen concentration and a higher carbon concentration, as compared to the naturally-sourced coal used to form the upgraded coal; (c) an upgraded coal formed by the method (M1); (d) an upgraded coal (C2) comprising an ash content of less than 5 wt.%, an oxygen concentration of 10-25 wt.% and a carbon concentration of 40-75 wt.%; (e) a graphene film or a graphene quantum dot formed from the upgraded coal (C2); and (f) a graphene quantum dot comprising at least one fluorescence emission maxima at 395 nm excitation of 450-550 nm. DESCRIPTION OF DRAWING(S) - The figure illustrates a schematic of an autoclave reactor system. Autoclave reactor system (10) Stirrer assembly (20) Stirring motor (30) Reactor vessel (40)