{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,2,26]],"date-time":"2026-02-26T20:43:04Z","timestamp":1772138584514,"version":"3.50.1"},"reference-count":43,"publisher":"MDPI AG","issue":"6","license":[{"start":{"date-parts":[[2025,6,15]],"date-time":"2025-06-15T00:00:00Z","timestamp":1749945600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2023YFC2907305"],"award-info":[{"award-number":["2023YFC2907305"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["52204167"],"award-info":[{"award-number":["52204167"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2024JJ6504"],"award-info":[{"award-number":["2024JJ6504"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100012166","name":"National Key Research and Development Program of China","doi-asserted-by":"publisher","award":["2022XQLH106"],"award-info":[{"award-number":["2022XQLH106"]}],"id":[{"id":"10.13039\/501100012166","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["2023YFC2907305"],"award-info":[{"award-number":["2023YFC2907305"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["52204167"],"award-info":[{"award-number":["52204167"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["2024JJ6504"],"award-info":[{"award-number":["2024JJ6504"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["2022XQLH106"],"award-info":[{"award-number":["2022XQLH106"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Hunan Provincial Natural Science Foundation of China","award":["2023YFC2907305"],"award-info":[{"award-number":["2023YFC2907305"]}]},{"name":"Hunan Provincial Natural Science Foundation of China","award":["52204167"],"award-info":[{"award-number":["52204167"]}]},{"name":"Hunan Provincial Natural Science Foundation of China","award":["2024JJ6504"],"award-info":[{"award-number":["2024JJ6504"]}]},{"name":"Hunan Provincial Natural Science Foundation of China","award":["2022XQLH106"],"award-info":[{"award-number":["2022XQLH106"]}]},{"name":"Graduate University-Enterprise Joint Innovation Program of Central South University","award":["2023YFC2907305"],"award-info":[{"award-number":["2023YFC2907305"]}]},{"name":"Graduate University-Enterprise Joint Innovation Program of Central South University","award":["52204167"],"award-info":[{"award-number":["52204167"]}]},{"name":"Graduate University-Enterprise Joint Innovation Program of Central South University","award":["2024JJ6504"],"award-info":[{"award-number":["2024JJ6504"]}]},{"name":"Graduate University-Enterprise Joint Innovation Program of Central South University","award":["2022XQLH106"],"award-info":[{"award-number":["2022XQLH106"]}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["BDCC"],"abstract":"<jats:p>Real-time ash content control in dense medium coal separation is challenged by time lags between detection and density adjustment, along with nonlinear\/noisy signals. This study proposes a hybrid model for clean coal ash content in dense medium separation by integrating empirical mode decomposition, long short-term memory networks, and sparrow search algorithm optimization. A key innovation lies in removing noise-containing intrinsic mode functions (IMFs) via EMD to ensure clean signal input to the LSTM model. Utilizing production data from a Shanxi coal plant, EMD decomposes ash content time series into intrinsic mode functions (IMFs) and residuals. High-frequency noise-containing IMFs are selectively removed, while LSTM predicts retained components. SSA optimizes LSTM parameters (learning rate, hidden layers, epochs) to minimize prediction errors. Results demonstrate the EMD-IMF1-LSTM-SSA model achieves superior accuracy (RMSE: 0.0099, MAE: 0.0052, MAPE: 0.047%) and trend consistency (NSD: 12), outperforming baseline models. The study also proposes the novel \u201cVector Value of the Radial Difference (VVRD)\u201d metric, which effectively quantifies prediction trend accuracy. By resolving time-lag issues and mitigating noise interference, the model enables precise ash content prediction 16 min ahead, supporting automated density control, reduced energy waste, and eco-friendly coal processing. This research provides practical tools and new metrics for intelligent coal separation in the context of green mining.<\/jats:p>","DOI":"10.3390\/bdcc9060159","type":"journal-article","created":{"date-parts":[[2025,6,16]],"date-time":"2025-06-16T04:06:24Z","timestamp":1750046784000},"page":"159","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":2,"title":["Time Series Prediction Method of Clean Coal Ash Content in Dense Medium Separation Based on the Improved EMD-LSTM Model"],"prefix":"10.3390","volume":"9","author":[{"given":"Kai","family":"Cheng","sequence":"first","affiliation":[{"name":"School of Resources and Safety Engineering, Central South University, Changsha 410083, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Xiaokang","family":"Zhang","sequence":"additional","affiliation":[{"name":"Tianhe Daoyun (Beijing) Technology Co., Ltd., Beijing 100176, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Keping","family":"Zhou","sequence":"additional","affiliation":[{"name":"School of Resources and Safety Engineering, Central South University, Changsha 410083, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Chenao","family":"Zhou","sequence":"additional","affiliation":[{"name":"School of Resources and Safety Engineering, Central South University, Changsha 410083, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3677-4561","authenticated-orcid":false,"given":"Jielin","family":"Li","sequence":"additional","affiliation":[{"name":"School of Resources and Safety Engineering, Central South University, Changsha 410083, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2582-1302","authenticated-orcid":false,"given":"Chun","family":"Yang","sequence":"additional","affiliation":[{"name":"School of Resources and Safety Engineering, Central South University, Changsha 410083, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Yurong","family":"Guo","sequence":"additional","affiliation":[{"name":"School of Resources and Safety Engineering, Central South University, Changsha 410083, China"}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Ranfeng","family":"Wang","sequence":"additional","affiliation":[{"name":"School of Mining Engineering, Taiyuan University of Technology, Taiyuan 030600, China"}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"1968","published-online":{"date-parts":[[2025,6,15]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"19","DOI":"10.1016\/j.jclepro.2018.06.306","article-title":"A novel and effective method for coal slime reduction of thermal coal processing","volume":"198","author":"Zhang","year":"2018","journal-title":"J. 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