{"cited_by_count":369767,"description":"This cluster of papers focuses on the geochemistry, utilization, and environmental impact of coal and its byproducts. It covers topics such as trace elements in coal, fly ash characterization, rare earth elements recovery, alumina extraction, phytoremediation of coal ash disposal sites, and the distribution of heavy metals.","display_name":"Coal and Its By-products","domain_id":"3","external_ids":{"openalex":"https://openalex.org/T12218","wikipedia":"https://en.wikipedia.org/wiki/Coal_geochemistry"},"field_id":"19","id":"T12218","keywords":[{"display_name":"coal geochemistry","id":"coal-geochemistry","score":0.8531,"url":"https://openalex.org/keywords/coal-geochemistry"},{"display_name":"coal rank","id":"coal-rank","score":0.2263,"url":"https://openalex.org/keywords/coal-rank"},{"display_name":"coal fly ash","id":"coal-fly-ash","score":0.2155,"url":"https://openalex.org/keywords/coal-fly-ash"},{"display_name":"coal ash","id":"coal-ash","score":0.2301,"url":"https://openalex.org/keywords/coal-ash"},{"display_name":"coal petrography","id":"coal-petrography","score":0.5018,"url":"https://openalex.org/keywords/coal-petrography"},{"display_name":"coal combustion by-products","id":"coal-combustion-residuals","score":0.2224,"url":"https://openalex.org/keywords/coal-combustion-residuals"},{"display_name":"vitrinite","id":"vitrinite","score":0.3501,"url":"https://openalex.org/keywords/vitrinite"},{"display_name":"coal petrology","id":"coal-petrology","score":0.5529,"url":"https://openalex.org/keywords/coal-petrology"},{"display_name":"coalification","id":"coalification","score":0.4049,"url":"https://openalex.org/keywords/coalification"},{"display_name":"coal macerals","id":"coal-macerals","score":0.4324,"url":"https://openalex.org/keywords/coal-macerals"},{"display_name":"inertinite","id":"inertinite","score":0.4043,"url":"https://openalex.org/keywords/inertinite"},{"display_name":"coal mineralogy","id":"coal-mineralogy","score":0.7623,"url":"https://openalex.org/keywords/coal-mineralogy"},{"display_name":"maceral composition","id":"maceral-composition","score":0.3901,"url":"https://openalex.org/keywords/maceral-composition"},{"display_name":"trace elements in coal","id":"trace-elements-in-coal","score":0.8975,"url":"https://openalex.org/keywords/trace-elements-in-coal"},{"display_name":"coal formation","id":"coal-formation","score":0.3194,"url":"https://openalex.org/keywords/coal-formation"},{"display_name":"liptinite","id":"liptinite","score":0.4773,"url":"https://openalex.org/keywords/liptinite"},{"display_name":"coal chemistry","id":"coal-chemistry","score":0.2041,"url":"https://openalex.org/keywords/coal-chemistry"},{"display_name":"coal composition","id":"coal-composition","score":0.2752,"url":"https://openalex.org/keywords/coal-composition"},{"display_name":"macerals","id":"macerals","score":0.3562,"url":"https://openalex.org/keywords/macerals"},{"display_name":"tonstein","id":"tonstein","score":0.4549,"url":"https://openalex.org/keywords/tonstein"},{"display_name":"huminite","id":"huminite","score":0.6538,"url":"https://openalex.org/keywords/huminite"},{"display_name":"Permian coal","id":"permian-coal","score":0.5621,"url":"https://openalex.org/keywords/permian-coal"},{"display_name":"coal-forming environment","id":"coal-forming-environment","score":0.5929,"url":"https://openalex.org/keywords/coal-forming-environment"},{"display_name":"coal mineral matter","id":"coal-mineral-matter","score":0.4158,"url":"https://openalex.org/keywords/coal-mineral-matter"},{"display_name":"fusinite","id":"fusinite","score":0.476,"url":"https://openalex.org/keywords/fusinite"}],"legacy_keywords":["Coal Geochemistry","Trace Elements","Fly Ash","Rare Earth Elements","Mineralogy","Environmental Impact","Alumina Recovery","Phytoremediation","Heavy Metals","Element Distribution"],"openalex_id":"https://openalex.org/T12218","source_created_date":"2024-01-23T15:27:13","source_updated_date":"2026-10-17T03:02:00","subfield_id":"1906","url":"/topics/T12218","works_api_url":"https://api.openalex.org/works?filter=topics.id:T12218","works_count":31418,"label":"Coal and Its By-products","provider":"openalex","revision":"cf7eae7afa93b303","taxonomy_revision":"f050b5d4780b1289","title":"Coal and Its By-products","kind":"topic-directory","aeo_cohort":"topic-directory","catalogue_revision":"f050b5d4780b1289","numeric_address":"36183607048306931","address_version":"morton4x16-v1","coordinates":[3,19,1906,12218],"answer_status":"Directory metadata; local answer requires separate source review","truth_status":"Subject descriptor, not a factual answer or a demonstrated knowledge gap","reviewed_answer":null}