The Jinyinshan-Huangdi′nao Li deposit (12,000 t Li_(2)O @ 0.60%) was recently discovered in southern Hubei Province, South China. This deposit is divided into two ore sections, namely, Jinyinshan (0.24–1.32 wt.% Li2...The Jinyinshan-Huangdi′nao Li deposit (12,000 t Li_(2)O @ 0.60%) was recently discovered in southern Hubei Province, South China. This deposit is divided into two ore sections, namely, Jinyinshan (0.24–1.32 wt.% Li2O) and Huangdi′nao (0.20–0.47 wt.% Li_(2)O). The dominant Li-bearing phase and mechanism for Li enrichment remain unclear. Herein, a comprehensive study of ore geology, mineralogy and geochemistry is conducted. Field and petrographic investigations revealed that Li mineralization in the deposit was fault-controlled and that the altered metasedimentary rocks and hydrothermal veins with intensive Li mineralization contained high abundances of Li-rich clay minerals. Whole-rock XRD and in situ analyses of SEM-EDS, EMPA and LA-ICP-MS of clay minerals reveal that cookeite (0.99–2.80 wt.% Li_(2)O) is the dominant Li-bearing phase, with subordinate illite (0.02–0.57 wt.% Li_(2)O). The widespread replacement of Li-enriched illite by cookeite combined with the compositional continuum suggests that cookeite was likely formed by the hydrothermal replacement of illite at a temperature of 240–270 ℃, as constrained by chlorite geothermometry (with average temperatures of 254 ± 2℃ in Jinyinshan and 259 ± 2 ℃ in Huangdi′nao). Since metasedimentary rocks of the Neoproterozoic Lengjiaxi Group in the deposit with variable Li anomalies host abundant Li-rich illite, Li mineralization was inferred to have occurred via hydrothermal metasomatism of these clay-rich clastic rocks. The hydrothermal fluids may have been driven by a deep magmatic heat source, as evidenced by previously reported U-Pb dating of apatite from the clay-Li ore, similar to the age of the Mufushan granitic batholith in the south, both of which are Early Cretaceous. The deep-sourced hydrothermal fluids caused the mobilization, migration and reprecipitation of Li as Li-rich clays along the fault zones. This mechanism of Li mineralization is different from existing models for clay-Li deposits worldwide, and this deposit can be classified as a new type, namely, fault-controlled hydrothermal metasomatic clay-Li deposit. Similar deposits are highly prospective both regionally and worldwide.展开更多
Limited research is available on lithium extraction technology for clay-type lithium deposits with relatively low lithium content.In this study,we investigated the effects of lithium extraction from lithium-poor clay ...Limited research is available on lithium extraction technology for clay-type lithium deposits with relatively low lithium content.In this study,we investigated the effects of lithium extraction from lithium-poor clay ores using oxalic acid.The ore was first calcined and then fully mixed with solid oxalic acid powder,followed by water leaching.Raw material analysis revealed that the primary lithium-containing mineral was cookeite,with a lithium oxide content of 0.57%.The X-ray diffraction(XRD)patterns of the mineral phase before and after calcination at different temperatures revealed that the structure of the ores calcined at 300 and 400℃ was similar to that of the original ore.However,in the XRD patterns of the ore calcined at 500℃,certain characteristic peaks of cookeite weakened or disappeared.Upon calcination at 600℃,the hydroxyl group of cookeite was removed,amorphous phase of cookeite appeared,and maximum leaching yield was attained.Using response surface methodology optimization,the optimal calcination temperature and time;acid-to-ore and water-to-ore ratios;and reaction temperature and time were 600℃ and 2 min;1:1 and 4 mL/g;and 95℃ and 6 h,respectively.The leaching yield under these optimal conditions was 92.33%.The results of this study revealed that lithium ions could be effectively extracted from mines using oxalic acid.展开更多
基金financially supported by projects from the National Natural Science Foundation of China (Nos. 92162323, 42321001)the National Key R&D Program of China (No. 2017YFC0602405)a project from the Hubei Geological Bureau ([2019]09).
文摘The Jinyinshan-Huangdi′nao Li deposit (12,000 t Li_(2)O @ 0.60%) was recently discovered in southern Hubei Province, South China. This deposit is divided into two ore sections, namely, Jinyinshan (0.24–1.32 wt.% Li2O) and Huangdi′nao (0.20–0.47 wt.% Li_(2)O). The dominant Li-bearing phase and mechanism for Li enrichment remain unclear. Herein, a comprehensive study of ore geology, mineralogy and geochemistry is conducted. Field and petrographic investigations revealed that Li mineralization in the deposit was fault-controlled and that the altered metasedimentary rocks and hydrothermal veins with intensive Li mineralization contained high abundances of Li-rich clay minerals. Whole-rock XRD and in situ analyses of SEM-EDS, EMPA and LA-ICP-MS of clay minerals reveal that cookeite (0.99–2.80 wt.% Li_(2)O) is the dominant Li-bearing phase, with subordinate illite (0.02–0.57 wt.% Li_(2)O). The widespread replacement of Li-enriched illite by cookeite combined with the compositional continuum suggests that cookeite was likely formed by the hydrothermal replacement of illite at a temperature of 240–270 ℃, as constrained by chlorite geothermometry (with average temperatures of 254 ± 2℃ in Jinyinshan and 259 ± 2 ℃ in Huangdi′nao). Since metasedimentary rocks of the Neoproterozoic Lengjiaxi Group in the deposit with variable Li anomalies host abundant Li-rich illite, Li mineralization was inferred to have occurred via hydrothermal metasomatism of these clay-rich clastic rocks. The hydrothermal fluids may have been driven by a deep magmatic heat source, as evidenced by previously reported U-Pb dating of apatite from the clay-Li ore, similar to the age of the Mufushan granitic batholith in the south, both of which are Early Cretaceous. The deep-sourced hydrothermal fluids caused the mobilization, migration and reprecipitation of Li as Li-rich clays along the fault zones. This mechanism of Li mineralization is different from existing models for clay-Li deposits worldwide, and this deposit can be classified as a new type, namely, fault-controlled hydrothermal metasomatic clay-Li deposit. Similar deposits are highly prospective both regionally and worldwide.
基金supported by Research and Demonstration Project on Key Technologies for Efficient Separation and Extraction of Lithium Resources in Guizhou Province([2022]ZD007).
文摘Limited research is available on lithium extraction technology for clay-type lithium deposits with relatively low lithium content.In this study,we investigated the effects of lithium extraction from lithium-poor clay ores using oxalic acid.The ore was first calcined and then fully mixed with solid oxalic acid powder,followed by water leaching.Raw material analysis revealed that the primary lithium-containing mineral was cookeite,with a lithium oxide content of 0.57%.The X-ray diffraction(XRD)patterns of the mineral phase before and after calcination at different temperatures revealed that the structure of the ores calcined at 300 and 400℃ was similar to that of the original ore.However,in the XRD patterns of the ore calcined at 500℃,certain characteristic peaks of cookeite weakened or disappeared.Upon calcination at 600℃,the hydroxyl group of cookeite was removed,amorphous phase of cookeite appeared,and maximum leaching yield was attained.Using response surface methodology optimization,the optimal calcination temperature and time;acid-to-ore and water-to-ore ratios;and reaction temperature and time were 600℃ and 2 min;1:1 and 4 mL/g;and 95℃ and 6 h,respectively.The leaching yield under these optimal conditions was 92.33%.The results of this study revealed that lithium ions could be effectively extracted from mines using oxalic acid.
