{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T08:27:48Z","timestamp":1787646468902,"version":"build-2736575974"},"reference-count":28,"publisher":"MDPI AG","issue":"17","license":[{"start":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T00:00:00Z","timestamp":1787616000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/100015811","name":"the Key Research and Development Program of the Ningxia Hui Autonomous Region","doi-asserted-by":"publisher","award":["2024BEE01003"],"award-info":[{"award-number":["2024BEE01003"]}],"id":[{"id":"10.13039\/100015811","id-type":"DOI","asserted-by":"publisher"}]},{"name":"Helanshan Laboratory","award":["HLS-2025-PDJH-004"],"award-info":[{"award-number":["HLS-2025-PDJH-004"]}]},{"DOI":"10.13039\/100015811","name":"the Natural Science Fund of Ningxia","doi-asserted-by":"publisher","award":["2026AAC030341"],"award-info":[{"award-number":["2026AAC030341"]}],"id":[{"id":"10.13039\/100015811","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Materials"],"abstract":"<jats:p>The occurrence characteristics of impurities and the precise technologies used for their removal are the main factors limiting the high-end applications of quartz sand. To simultaneously achieve ultrahigh purity and a high yield while incorporating a sustainable waste acid treatment strategy, quartz sand (SP1) from India was selected as the research material. A stepwise experimental scheme involving single-acid and mixed-acid treatments was adopted to optimize the purification conditions, incorporating a complete process of pretreatment, acid leaching, and post-treatment along with a defined waste liquid management method. The raw SP1 quartz samples and samples treated under the optimal acid-washing conditions were characterized through qualitative and quantitative analyses, including X-ray diffraction, Raman spectroscopy, scanning electron microscopy, and inductively coupled plasma mass spectrometry. The optimal result for the single-acid system was obtained by treating quartz sand with 70 mL of hydrofluoric acid at 120 \u00b0C for 2 h, resulting in a purity of 99.9963%. For the mixed-acid system, the volume ratio of hydrofluoric acid, hydrochloric acid, and nitric acid was maintained at 1:6:2, and acid leaching was performed at a constant temperature of 120 \u00b0C for 5 h. Under these conditions, the aluminum and iron contents were reduced to 15.23 and 0.15 \u03bcg\/g, respectively, while the purity and production yield of the acid-washed quartz sand reached 99.9964% and 82.11%, respectively. Based on comprehensive consideration of the purification effectiveness and process economy, an HF:HCl:HNO3 volume ratio of 1:6:2 and an acid-washing reaction time of 5 h were selected, providing a stable purity exceeding 99.996%. This study provides a theoretical and technical basis for the standardized and sustainable production of high-purity quartz sand.<\/jats:p>","DOI":"10.3390\/ma19173604","type":"journal-article","created":{"date-parts":[[2026,8,25]],"date-time":"2026-08-25T08:00:48Z","timestamp":1787644848000},"page":"3604","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Study on Process Optimization and Mechanism of Quartz Sand Acid Leaching and Purification"],"prefix":"10.3390","volume":"19","author":[{"given":"Ziyang","family":"Bai","sequence":"first","affiliation":[{"name":"School of Materials Science and Engineering, North Minzu University, Yinchuan 750021, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Huan","family":"Xiong","sequence":"additional","affiliation":[{"name":"Ningxia SiFusion Co., Ltd., Yinchuan 750021, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Yupeng","family":"He","sequence":"additional","affiliation":[{"name":"Ningxia SiFusion Co., Ltd., Yinchuan 750021, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Youjun","family":"Lu","sequence":"additional","affiliation":[{"name":"School of Materials Science and Engineering, North Minzu University, Yinchuan 750021, China"},{"name":"Helanshan Laboratory, Yinchuan 750021, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0009-0009-2971-1387","authenticated-orcid":false,"given":"Bo","family":"Ma","sequence":"additional","affiliation":[{"name":"School of Materials Science and Engineering, North Minzu University, Yinchuan 750021, China"},{"name":"Helanshan Laboratory, Yinchuan 750021, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Wenzhou","family":"Sun","sequence":"additional","affiliation":[{"name":"School of Materials Science and Engineering, North Minzu University, Yinchuan 750021, China"},{"name":"Helanshan Laboratory, Yinchuan 750021, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Haibei","family":"Shi","sequence":"additional","affiliation":[{"name":"Ningxia SiFusion Co., Ltd., Yinchuan 750021, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Jianjun","family":"Wang","sequence":"additional","affiliation":[{"name":"Ningxia SiFusion Co., Ltd., Yinchuan 750021, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-9981-6293","authenticated-orcid":false,"given":"Maohui","family":"Li","sequence":"additional","affiliation":[{"name":"School of Materials Science and Engineering, North Minzu University, Yinchuan 750021, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,8,25]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"101280","DOI":"10.1016\/j.pmatsci.2024.101280","article-title":"Crucibles and coatings for silicon melting and crystallization: An in-depth review of key considerations","volume":"144","author":"Hendawi","year":"2024","journal-title":"Prog. 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