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Léon Dejonghe - One of the best experts on this subject based on the ideXlab platform.
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The “Calamine” nonsulfide Zn–Pb deposits of Belgium: Petrographical, mineralogical and geochemical characterization
Ore Geology Reviews, 2008Co-Authors: Vito Coppola, Maria Boni, H. Albert Gilg, Giuseppina Balassone, Léon DejongheAbstract:Abstract The Belgian nonsulfide Zn deposits represent the historical basis for the zinc mining and smelting industry in Europe. The zinc ores were called “Calamines” and consist of a mixture of Zn carbonates (smithsonite, hydrozincite) and Zn silicates (hemimorphite, willemite and Zn clays), with a variable content of Pb minerals. The “Calamines” are considered to be oxidation products of primary sulfide ores. The most important was the La Calamine orebody (more than 600,000 tons of Zn metal) that was continuously exploited for several centuries. Nonsulfide ores were also exploited at Schmalgraf, Engis, Dickenbusch, Fossey, Rocheux-Oneux, Welkenraedt and in other smaller deposits (all no longer accessible for study), where the “Calamines” extended from the surface to an average depth of 40 to 50 m. The primary Zn–Pb sulfide mineralization consists of post-Variscan hydrothermal veins and replacement bodies, mostly occurring in the Dinantian (Visean) limestones. The sulfides intersect the Paleozoic rocks and are truncated and unconformably covered by Late Cretaceous sediments (Santonian Aachen Fm.). The same setting has been observed for the nonsulfide ores, suggesting an Early to Mid-Cretaceous weathering, consistent with other geological and geochronological data on paleoweathering in Europe. The extensive occurrence of willemite, that appears to be the first deposited nonsulfide mineral, is a striking particularity of the Belgian “Calamines”. Most fluid inclusions in willemite (80%) and all inclusions in smithsonite are monophase (aqueous). Ice melting temperatures suggest salinities between 0 and 5 wt.% NaCl equiv. Homogenization temperatures of rare two-phase inclusions (liquid + vapor) in willemite display a large variation between 80 and 190°, an interval matching the temperature ranges of other willemite ores throughout the world, so far considered of hydrothermal origin. The stable isotope variation of Belgian smithsonites and cerussites is very similar to the range measured in other supergene nonsulfide deposits similar to those of SW Sardinia. Belgian smithsonites exhibit a limited range of δ18O values from 27.1 to 30.6‰, averaging 28.4‰ ± 0.8‰ V-SMOW. This limited range points to a relatively uniform isotope composition of the oxidizing waters and constant temperatures of smithsonite crystallization. Carbon isotope values, even from the same mine, show a considerable range from − 11.6 to − 1.6‰. This extensive range indicates at least two carbon sources: 13C-depleted carbon derived from the organic matter in the soils and 13C-enriched carbon originating from marine carbonate host rocks. Cerussites have oxygen isotope values ranging from 16.8 to 19.3‰, averaging 17.8 ± 1.0‰ and carbon isotope values of − 18.4 to − 14.7‰. The metallic deposits of Eastern Belgium have undergone a polyphase history, which started with a possibly Jurassic sulfide mineralization, followed by oxidation under high silica activities and consequently by supergene weathering. Owing to structure and mineralogical association, we do not consider the high homogenization temperatures as reliable minimum temperature estimates of willemite formation. However, it is possible that the willemite concentrations could have been derived from low-temperature, localized hydrothermal processes caused by deeply reaching oxidizing fluids. Smithsonite and hemimorphite, often developed at the expenses of willemite, have all the characteristics of supergene oxidation products.
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STATE OF THE ART ON THE "Calamine"-TYPE ZINC DEPOSITS OF BELGIUM
Geologica Belgica, 2007Co-Authors: Maria Boni, Léon Dejonghe, C. Ballasone, V. Coppola, Albert GilgAbstract:The Belgian “Calamine”-type nonsulphide Zn deposits, mainly located in the Verviers Synclinorium in the northeastern part of the country, represent the historical basis for zinc mining and smelting industry in Europe. The most important was the La Calamine orebody (more than 600,000 tons of Zn metal) that was continuously exploited for several centuries. Nonsulphide ores associated to sulphides, were also exploited at Schmalgraf, Engis, Dickenbusch, Fossey, Rocheux-Oneux, Welkenraedt and other smaller deposits (Dejonghe, 1998). Across the border to Germany, in the north Eifel, similar Zn-Pb deposits as the Belgian ones (also consisting of both primary sulphides and Calamines) were exploited in the past in the Aachen-Stolberg district, but their economic potential was much lower than in Belgium. The primary Zn-Pb sulphide mineralization consists of post-Variscan hydrothermal veins and replacementand breccia bodies (Fig. 1A), mostly occurring at the top of
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the Calamine type zinc lead deposits in belgium and west germany a product of mesozoic palaeoweathering processes
Geologica Belgica, 2005Co-Authors: Léon Dejonghe, Maria BoniAbstract:The word "Calamine", designating non-sulphide Zn-ores of supergene origin in carbonate rocks, originates from the Belgian locality "La Calamine" where an ore deposit was exploited from the 14 th century up to 1884. The genesis and age of La Calamine, described in the literature as a palaeokarstic type of deposit, have never been fully understood. Likewise, the age of the deep supergene alteration of Zn-Pb veins exploited in Belgian and German neighbouring mining districts has never been clearly determined. This paper aims at identifying the geological constraints responsible for the genesis of willemite-smithsonite-bearing La Calamine deposit, as well as of the deep- reaching gossans of the surrounding Zn-Pb veins. The kaolinised regolith remnants ranging from Uppermost Jurassic to Lower Cretaceous, which developed on the post-Variscan palaeosurface, could be one of the surface expressions of the weathering responsible for the genesis of non-sulphide Zn-ore deposits in Belgium and Germany. Locally, Upper Cretaceous sediments, whose deposition interrupted the weathering process, cover the regolith. Neither Cainozoic weathering, that was responsible in Belgium for halloysite accumulations at the bottom of giant cryptokarsts, nor Quaternary landscape modelling, should have played a major role in the formation of the economic "Calamine-type" Zn-deposits.
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zinc lead deposits of belgium
Ore Geology Reviews, 1998Co-Authors: Léon DejongheAbstract:The exploitation of Belgian zinc–lead deposits dates back to prehistoric times. Its apogee was between 1850 and 1870 and the last mine was closed in 1946. During the period 1837–1945, during which time production levels were recorded, the tonnage of exploited metals reached about 1 500 000 tons Pb+Zn with a Zn/Pb ratio of 8–9. The mineralogy of the deposits is generally simple: sphalerite, galena, pyrite or marcasite, and locally Ni- and Co-sulfides. Several ore deposit types may be distinguished, including syndiagenetic-, vein and connected flat-, and paleokarstic types. The syndiagenetic deposits are made up of numerous disseminated-type deposits with low grades and small tonnages. They are linked to reef facies of Frasnian (=Upper Devonian) carbonate rocks. The largest exploited vein-type deposits are hosted in Dinantian (=Lower Carboniferous) carbonate rocks. Lead isotopic studies reveal that the main primary source of the metals is in Middle and Upper Devonian sedimentary rocks. Hydrothermal solutions precipitated their metals at temperatures <180°C (110°C in the Verviers Synclinorium) and pressures of 108 Pa (<2×107 Pa in the Verviers Synclinorium). Salinities of the fluids were often between 10 and 23 equiv. wt.% NaCl. The origin of the vein-type deposits is related to the migration of underground waters, likely gravity-driven, that leach the metals of the surrounding sedimentary rocks (mainly, those of Devonian age, after Pb isotopic data). The La Calamine paleokarstic deposit was the largest Zn ore body in Belgium. It was continuously exploited from the 14th century up to 1884 and produced more than 600 000 tonnes of zinc metal. It was at La Calamine that the chemist Dony, from Liege, invented the first industrial process to transform the Calamines into malleable zinc. This was patented by Napoleon I in 1810. Because Belgium occupies an area of the Variscan foreland between Germany and Ireland, a comparison between deposits of these countries is performed. Belgian Zn–Pb syn-diagenetic deposit are however of types different from the volcanogenic massive sulfide deposits of Germany, as well as from the strata-bound lenses of Ireland. Prospecting by private companies during the past 50 years has increased the tonnage of reserves adjacent to known deposits. Lithogeochemical prospecting, however, has not led to the discovery of new economic ore deposits. The Chaudfontaine stratiform deposit, situated above a Frasnian biostrome, is the only recent drilling discovery.
Maria Boni - One of the best experts on this subject based on the ideXlab platform.
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The “Calamines” and the “Others”: The great family of supergene nonsulfide zinc ores
Ore Geology Reviews, 2015Co-Authors: Maria Boni, Nicola MondilloAbstract:Abstract “Nonsulfides” is a term, which comprises a series of oxidized Zn(Pb)-ore minerals. It has also been used to define a special deposit type, mainly considered as derived from the weathering of Zn(Pb) sulfide concentrations. However, nonsulfide zinc deposits have been distinguished between supergene and hypogene, according to their mineralogy, geological characteristics and genetic setting. The supergene deposits formed by weathering and oxidation at ambient temperatures, whereas the hypogene ones are considered hydrothermal, or associated with metamorphic processes on primary sulfide ores. In this review paper, a comparison between a number of several nonsulfide deposits has been carried out: typical “Calamines”, peculiar “Calamines” and “Others”. The whole group comprises deposits of typical supergene origin, mixed supergene–hypogene mineralizations, and oxidized concentrations characterized by different metals only locally associated with zinc. The Zn–Pb nonsulfide concentrations hosted in carbonate rocks, which are mainly attributed to “wall-rock replacement” and “direct-replacement” supergene processes, are the typical “Calamines” (Liege district, Belgium; Iglesias district, Italy; Silesia–Cracow district, Poland). Peculiar “Calamine” deposits are those mineralizations that have been generally considered as supergene, but which are instead genetically related, at least partly, to hypogene processes (e.g. Angouran, Iran; Jabali, Yemen), though mineralogically and texturally similar to supergene nonsulfide deposits. The “Others” are prevailingly supergene nonsulfide zinc deposits not hosted in carbonate rocks (Skorpion, Namibia; Yanque, Peru), or characterized by other metals as main commodities, like lead (Magellan, Australia), silver (Sierra Mojada, Mexico; Wonawinta, Australia) or vanadium (Otavi Mountainland, Namibia). Minerals of current economic importance in most “Calamine” deposits are smithsonite, hydrozincite, and cerussite. This mineralogical association is generally simple but, when the “Calamines” are dolomite-hosted, one of the consequences of the “wall-rock replacement” process is the generation of a series of economically useless Zn- and Mg-bearing mixed carbonate phases. Secondary deposits hosted in silicatic (sedimentary or volcanic) rocks mainly contain hemimorphite and/or sauconite. Lead-, Ag- and V-rich nonsulfide ores are characterized by a more complex mineralogical association: mixed Pb-carbonates, Pb-sulfates, Pb-phosphates, Pb-arsenates, various Ag-sulfosalts, and Zn–Pb–Cu-vanadates. Carbon and oxygen stable isotope studies allow distinguishing between supergene and hypogene nonsulfide deposits, evaluating the effects of oxidative heating and even gaining indirect paleoclimatic information. The oxygen-isotope variation of the individual carbonate minerals within a deposit is relatively small, indicating constant formation temperatures and a single, meteoric fluid source. Carbon-isotope values are highly variable, thus suggesting several isotopically distinct carbon sources. Periods of paleoclimatic switch-overs from seasonally humid/arid to hyperarid have been considered as the most favorable conditions for the formation and preservation of supergene nonsulfide deposits. However, while several recent nonsulfide deposits throughout the world are positioned between 15° and 45° N latitude, thus pointing to a warm and humid weathering climate, others have been deposited in sub-Arctic regions. The economic value of the nonsulfide Zn(Pb–Ag–V) ores is highly variable, because more than in the case of metallic sulfide deposits, it resides not only on the geological setting, but also on their mineralogy that can directly influence processing and metallurgy.
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The "Calamines" and the "Others": the great family of supergene nonsulfide zinc ores.
'Elsevier BV', 2015Co-Authors: Maria Boni, Nicola MondilloAbstract:"Nonsulfides" is a term,which comprises a series of oxidized Zn(Pb)-ore minerals. It has also been used to define a special deposit type, mainly considered as derived from the weathering of Zn(Pb) sulfide concentrations. However, nonsulfide zinc deposits have been distinguished between supergene and hypogene, according to their mineralogy, geological characteristics and genetic setting. The supergene deposits formed by weathering and oxidation at ambient temperatures, whereas the hypogene ones are considered hydrothermal, or associated with metamorphic processes on primary sulfide ores. In this review paper, a comparison between a number of several nonsulfide deposits has been carried out: typical "Calamines", peculiar "Calamines" and "Others". The whole group comprises deposits of typical supergene origin, mixed supergene, hypogene mineralizations, and oxidized concentrations characterized by different metals only locally associated with zinc. The Zn-Pb nonsulfide concentrations hosted in carbonate rocks, which are mainly attributed to "wall-rock replacement" and "direct-replacement" supergene processes, are the typical "Calamines" (Liège district, Belgium; Iglesias district, Italy; Silesia-Cracow district, Poland). Peculiar "Calamine" deposits are those mineralizations that have been generally considered as supergene, but which are instead genetically related, at least partly, to hypogene processes (e.g. Angouran, Iran; Jabali, Yemen), though mineralogically and texturally similar to supergene nonsulfide deposits. The "Others" are prevailingly supergene nonsulfide zinc deposits not hosted in carbonate rocks (Skorpion, Namibia; Yanque, Peru), or characterized by other metals as main commodities, like lead (Magellan, Australia), silver (Sierra Mojada, Mexico; Wonawinta, Australia) or vanadium (Otavi Mountainland, Namibia). Minerals of current economic importance in most "Calamine" deposits are smithsonite, hydrozincite, and cerussite. This mineralogical association is generally simple but, when the "Calamines" are dolomite-hosted, one of the consequences of the "wall-rock replacement" process is the generation of a series of economically useless Zn- and Mg-bearing mixed carbonate phases. Secondary deposits hosted in silicatic (sedimentary or volcanic) rocks mainly contain hemimorphite and/or sauconite. Lead-, Ag- and V-rich nonsulfide ores are characterized by a more complex mineralogical association: mixed Pb-carbonates, Pb-sulfates, Pb- phosphates, Pb-arsenates, various Ag-sulfosalts, and Zn-Pb-Cu-vanadates. Carbon and oxygen stable isotope studies allow distinguishing between supergene and hypogene nonsulfide deposits, evaluating the effects of oxidative heating and even gaining indirect paleoclimatic information. The oxygen-isotope variation of the individual carbonate minerals within a deposit is relatively small, indicating constant formation temperatures and a single, meteoric fluid source. Carbon-isotope values are highly variable, thus suggesting several isotopically distinct carbon sources. Periods of paleoclimatic switch-overs from seasonally humid/arid to hyperarid have been considered as the most favorable conditions for the formation and preservation of supergene nonsulfide deposits. However, while several recent nonsulfide deposits throughout the world are positioned between 15° and 45° N latitude, thus pointing to a warm and humid weathering climate, others have been deposited in sub-Arctic regions. The economic value of the nonsulfide Zn(Pb-Ag-V) ores is highly variable, because more than in the case of metallic sulfide deposits, it resides not only on the geological setting, but also on their mineralogy that can directly influence processing and metallurgy
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The “Calamine” nonsulfide Zn–Pb deposits of Belgium: Petrographical, mineralogical and geochemical characterization
Ore Geology Reviews, 2008Co-Authors: Vito Coppola, Maria Boni, H. Albert Gilg, Giuseppina Balassone, Léon DejongheAbstract:Abstract The Belgian nonsulfide Zn deposits represent the historical basis for the zinc mining and smelting industry in Europe. The zinc ores were called “Calamines” and consist of a mixture of Zn carbonates (smithsonite, hydrozincite) and Zn silicates (hemimorphite, willemite and Zn clays), with a variable content of Pb minerals. The “Calamines” are considered to be oxidation products of primary sulfide ores. The most important was the La Calamine orebody (more than 600,000 tons of Zn metal) that was continuously exploited for several centuries. Nonsulfide ores were also exploited at Schmalgraf, Engis, Dickenbusch, Fossey, Rocheux-Oneux, Welkenraedt and in other smaller deposits (all no longer accessible for study), where the “Calamines” extended from the surface to an average depth of 40 to 50 m. The primary Zn–Pb sulfide mineralization consists of post-Variscan hydrothermal veins and replacement bodies, mostly occurring in the Dinantian (Visean) limestones. The sulfides intersect the Paleozoic rocks and are truncated and unconformably covered by Late Cretaceous sediments (Santonian Aachen Fm.). The same setting has been observed for the nonsulfide ores, suggesting an Early to Mid-Cretaceous weathering, consistent with other geological and geochronological data on paleoweathering in Europe. The extensive occurrence of willemite, that appears to be the first deposited nonsulfide mineral, is a striking particularity of the Belgian “Calamines”. Most fluid inclusions in willemite (80%) and all inclusions in smithsonite are monophase (aqueous). Ice melting temperatures suggest salinities between 0 and 5 wt.% NaCl equiv. Homogenization temperatures of rare two-phase inclusions (liquid + vapor) in willemite display a large variation between 80 and 190°, an interval matching the temperature ranges of other willemite ores throughout the world, so far considered of hydrothermal origin. The stable isotope variation of Belgian smithsonites and cerussites is very similar to the range measured in other supergene nonsulfide deposits similar to those of SW Sardinia. Belgian smithsonites exhibit a limited range of δ18O values from 27.1 to 30.6‰, averaging 28.4‰ ± 0.8‰ V-SMOW. This limited range points to a relatively uniform isotope composition of the oxidizing waters and constant temperatures of smithsonite crystallization. Carbon isotope values, even from the same mine, show a considerable range from − 11.6 to − 1.6‰. This extensive range indicates at least two carbon sources: 13C-depleted carbon derived from the organic matter in the soils and 13C-enriched carbon originating from marine carbonate host rocks. Cerussites have oxygen isotope values ranging from 16.8 to 19.3‰, averaging 17.8 ± 1.0‰ and carbon isotope values of − 18.4 to − 14.7‰. The metallic deposits of Eastern Belgium have undergone a polyphase history, which started with a possibly Jurassic sulfide mineralization, followed by oxidation under high silica activities and consequently by supergene weathering. Owing to structure and mineralogical association, we do not consider the high homogenization temperatures as reliable minimum temperature estimates of willemite formation. However, it is possible that the willemite concentrations could have been derived from low-temperature, localized hydrothermal processes caused by deeply reaching oxidizing fluids. Smithsonite and hemimorphite, often developed at the expenses of willemite, have all the characteristics of supergene oxidation products.
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STATE OF THE ART ON THE "Calamine"-TYPE ZINC DEPOSITS OF BELGIUM
Geologica Belgica, 2007Co-Authors: Maria Boni, Léon Dejonghe, C. Ballasone, V. Coppola, Albert GilgAbstract:The Belgian “Calamine”-type nonsulphide Zn deposits, mainly located in the Verviers Synclinorium in the northeastern part of the country, represent the historical basis for zinc mining and smelting industry in Europe. The most important was the La Calamine orebody (more than 600,000 tons of Zn metal) that was continuously exploited for several centuries. Nonsulphide ores associated to sulphides, were also exploited at Schmalgraf, Engis, Dickenbusch, Fossey, Rocheux-Oneux, Welkenraedt and other smaller deposits (Dejonghe, 1998). Across the border to Germany, in the north Eifel, similar Zn-Pb deposits as the Belgian ones (also consisting of both primary sulphides and Calamines) were exploited in the past in the Aachen-Stolberg district, but their economic potential was much lower than in Belgium. The primary Zn-Pb sulphide mineralization consists of post-Variscan hydrothermal veins and replacementand breccia bodies (Fig. 1A), mostly occurring at the top of
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the Calamine type zinc lead deposits in belgium and west germany a product of mesozoic palaeoweathering processes
Geologica Belgica, 2005Co-Authors: Léon Dejonghe, Maria BoniAbstract:The word "Calamine", designating non-sulphide Zn-ores of supergene origin in carbonate rocks, originates from the Belgian locality "La Calamine" where an ore deposit was exploited from the 14 th century up to 1884. The genesis and age of La Calamine, described in the literature as a palaeokarstic type of deposit, have never been fully understood. Likewise, the age of the deep supergene alteration of Zn-Pb veins exploited in Belgian and German neighbouring mining districts has never been clearly determined. This paper aims at identifying the geological constraints responsible for the genesis of willemite-smithsonite-bearing La Calamine deposit, as well as of the deep- reaching gossans of the surrounding Zn-Pb veins. The kaolinised regolith remnants ranging from Uppermost Jurassic to Lower Cretaceous, which developed on the post-Variscan palaeosurface, could be one of the surface expressions of the weathering responsible for the genesis of non-sulphide Zn-ore deposits in Belgium and Germany. Locally, Upper Cretaceous sediments, whose deposition interrupted the weathering process, cover the regolith. Neither Cainozoic weathering, that was responsible in Belgium for halloysite accumulations at the bottom of giant cryptokarsts, nor Quaternary landscape modelling, should have played a major role in the formation of the economic "Calamine-type" Zn-deposits.
Nicola Mondillo - One of the best experts on this subject based on the ideXlab platform.
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The “Calamines” and the “Others”: The great family of supergene nonsulfide zinc ores
Ore Geology Reviews, 2015Co-Authors: Maria Boni, Nicola MondilloAbstract:Abstract “Nonsulfides” is a term, which comprises a series of oxidized Zn(Pb)-ore minerals. It has also been used to define a special deposit type, mainly considered as derived from the weathering of Zn(Pb) sulfide concentrations. However, nonsulfide zinc deposits have been distinguished between supergene and hypogene, according to their mineralogy, geological characteristics and genetic setting. The supergene deposits formed by weathering and oxidation at ambient temperatures, whereas the hypogene ones are considered hydrothermal, or associated with metamorphic processes on primary sulfide ores. In this review paper, a comparison between a number of several nonsulfide deposits has been carried out: typical “Calamines”, peculiar “Calamines” and “Others”. The whole group comprises deposits of typical supergene origin, mixed supergene–hypogene mineralizations, and oxidized concentrations characterized by different metals only locally associated with zinc. The Zn–Pb nonsulfide concentrations hosted in carbonate rocks, which are mainly attributed to “wall-rock replacement” and “direct-replacement” supergene processes, are the typical “Calamines” (Liege district, Belgium; Iglesias district, Italy; Silesia–Cracow district, Poland). Peculiar “Calamine” deposits are those mineralizations that have been generally considered as supergene, but which are instead genetically related, at least partly, to hypogene processes (e.g. Angouran, Iran; Jabali, Yemen), though mineralogically and texturally similar to supergene nonsulfide deposits. The “Others” are prevailingly supergene nonsulfide zinc deposits not hosted in carbonate rocks (Skorpion, Namibia; Yanque, Peru), or characterized by other metals as main commodities, like lead (Magellan, Australia), silver (Sierra Mojada, Mexico; Wonawinta, Australia) or vanadium (Otavi Mountainland, Namibia). Minerals of current economic importance in most “Calamine” deposits are smithsonite, hydrozincite, and cerussite. This mineralogical association is generally simple but, when the “Calamines” are dolomite-hosted, one of the consequences of the “wall-rock replacement” process is the generation of a series of economically useless Zn- and Mg-bearing mixed carbonate phases. Secondary deposits hosted in silicatic (sedimentary or volcanic) rocks mainly contain hemimorphite and/or sauconite. Lead-, Ag- and V-rich nonsulfide ores are characterized by a more complex mineralogical association: mixed Pb-carbonates, Pb-sulfates, Pb-phosphates, Pb-arsenates, various Ag-sulfosalts, and Zn–Pb–Cu-vanadates. Carbon and oxygen stable isotope studies allow distinguishing between supergene and hypogene nonsulfide deposits, evaluating the effects of oxidative heating and even gaining indirect paleoclimatic information. The oxygen-isotope variation of the individual carbonate minerals within a deposit is relatively small, indicating constant formation temperatures and a single, meteoric fluid source. Carbon-isotope values are highly variable, thus suggesting several isotopically distinct carbon sources. Periods of paleoclimatic switch-overs from seasonally humid/arid to hyperarid have been considered as the most favorable conditions for the formation and preservation of supergene nonsulfide deposits. However, while several recent nonsulfide deposits throughout the world are positioned between 15° and 45° N latitude, thus pointing to a warm and humid weathering climate, others have been deposited in sub-Arctic regions. The economic value of the nonsulfide Zn(Pb–Ag–V) ores is highly variable, because more than in the case of metallic sulfide deposits, it resides not only on the geological setting, but also on their mineralogy that can directly influence processing and metallurgy.
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The "Calamines" and the "Others": the great family of supergene nonsulfide zinc ores.
'Elsevier BV', 2015Co-Authors: Maria Boni, Nicola MondilloAbstract:"Nonsulfides" is a term,which comprises a series of oxidized Zn(Pb)-ore minerals. It has also been used to define a special deposit type, mainly considered as derived from the weathering of Zn(Pb) sulfide concentrations. However, nonsulfide zinc deposits have been distinguished between supergene and hypogene, according to their mineralogy, geological characteristics and genetic setting. The supergene deposits formed by weathering and oxidation at ambient temperatures, whereas the hypogene ones are considered hydrothermal, or associated with metamorphic processes on primary sulfide ores. In this review paper, a comparison between a number of several nonsulfide deposits has been carried out: typical "Calamines", peculiar "Calamines" and "Others". The whole group comprises deposits of typical supergene origin, mixed supergene, hypogene mineralizations, and oxidized concentrations characterized by different metals only locally associated with zinc. The Zn-Pb nonsulfide concentrations hosted in carbonate rocks, which are mainly attributed to "wall-rock replacement" and "direct-replacement" supergene processes, are the typical "Calamines" (Liège district, Belgium; Iglesias district, Italy; Silesia-Cracow district, Poland). Peculiar "Calamine" deposits are those mineralizations that have been generally considered as supergene, but which are instead genetically related, at least partly, to hypogene processes (e.g. Angouran, Iran; Jabali, Yemen), though mineralogically and texturally similar to supergene nonsulfide deposits. The "Others" are prevailingly supergene nonsulfide zinc deposits not hosted in carbonate rocks (Skorpion, Namibia; Yanque, Peru), or characterized by other metals as main commodities, like lead (Magellan, Australia), silver (Sierra Mojada, Mexico; Wonawinta, Australia) or vanadium (Otavi Mountainland, Namibia). Minerals of current economic importance in most "Calamine" deposits are smithsonite, hydrozincite, and cerussite. This mineralogical association is generally simple but, when the "Calamines" are dolomite-hosted, one of the consequences of the "wall-rock replacement" process is the generation of a series of economically useless Zn- and Mg-bearing mixed carbonate phases. Secondary deposits hosted in silicatic (sedimentary or volcanic) rocks mainly contain hemimorphite and/or sauconite. Lead-, Ag- and V-rich nonsulfide ores are characterized by a more complex mineralogical association: mixed Pb-carbonates, Pb-sulfates, Pb- phosphates, Pb-arsenates, various Ag-sulfosalts, and Zn-Pb-Cu-vanadates. Carbon and oxygen stable isotope studies allow distinguishing between supergene and hypogene nonsulfide deposits, evaluating the effects of oxidative heating and even gaining indirect paleoclimatic information. The oxygen-isotope variation of the individual carbonate minerals within a deposit is relatively small, indicating constant formation temperatures and a single, meteoric fluid source. Carbon-isotope values are highly variable, thus suggesting several isotopically distinct carbon sources. Periods of paleoclimatic switch-overs from seasonally humid/arid to hyperarid have been considered as the most favorable conditions for the formation and preservation of supergene nonsulfide deposits. However, while several recent nonsulfide deposits throughout the world are positioned between 15° and 45° N latitude, thus pointing to a warm and humid weathering climate, others have been deposited in sub-Arctic regions. The economic value of the nonsulfide Zn(Pb-Ag-V) ores is highly variable, because more than in the case of metallic sulfide deposits, it resides not only on the geological setting, but also on their mineralogy that can directly influence processing and metallurgy
Cui Yu Yin - One of the best experts on this subject based on the ideXlab platform.
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Study on the Calamine/Sodium Alginate Modified Viscose Fiber
Advanced Materials Research, 2011Co-Authors: Dong Qi Liu, Shu Fa Han, Yufeng Zhang, Ying Liu, Cui Yu YinAbstract:In this article we successfully prepared Calamine / sodium alginate viscose fiber. Good dispersion and stability of the modified solution was prepared by dispersing Calamine in alkaline solution of sodium alginate, and then mixed it with viscose spinning solution by spinning injection methods. Moreover, the stability of Calamine / sodium alginate solution, the effect of concentration of Calamine on the fiber properties is studied in this paper. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and physical mechanical performance are test to characterize the structure and the performance of the Calamine / sodium alginate viscose fiber.
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study on the Calamine sodium alginate modified viscose fiber
Advanced Materials Research, 2011Co-Authors: Dong Qi Liu, Shu Fa Han, Yufeng Zhang, Ying Liu, Cui Yu YinAbstract:In this article we successfully prepared Calamine / sodium alginate viscose fiber. Good dispersion and stability of the modified solution was prepared by dispersing Calamine in alkaline solution of sodium alginate, and then mixed it with viscose spinning solution by spinning injection methods. Moreover, the stability of Calamine / sodium alginate solution, the effect of concentration of Calamine on the fiber properties is studied in this paper. Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM) and physical mechanical performance are test to characterize the structure and the performance of the Calamine / sodium alginate viscose fiber.
Keli Chen - One of the best experts on this subject based on the ideXlab platform.
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Study on the Processing Technology of Calamine Calcination by Near-Infrared Spectroscopy
Journal of Spectroscopy, 2019Co-Authors: Xiaodong Zhang, Long Chen, Yu Bai, Keli ChenAbstract:Near-infrared spectroscopy has been widely used in qualitative and quantitative analysis and online monitoring in the production process of traditional Chinese medicines. The aim was to establish a fast determination model of zinc oxide (ZnO) content in calcined Calamine and to explore methods through judging the end point of Calamine calcination. Eight batches of Calamine samples sourced from hydrozincite with different sizes and textures were calcined at different temperatures. During the calcination process, ZnO contents, X-ray diffraction (XRD) patterns, and near-infrared spectra of the samples were used to analyze their changes rules. The model of determining ZnO content of calcined Calamine was established to use near-infrared spectroscopy based on the partial least squares (PLS) regression algorithm. In addition, this paper summarized the change rules of Calamine in calcination according to XRD patterns, using the “K value” quantitative method to define the characteristic T value. When the T value was equal to 1.00 (100%), that is to say, the Calamine sample was completely calcined. Then, matching the near-infrared spectroscopy data with the T value and establishing the T value analysis model using the PLS algorithm were performed. Through cross and independent validation and evaluation, it was proved that the two models were very effective and had strong predictive abilities. Finally, the purpose of the online monitoring of the calcination process and controlling the quality of the calcined Calamine was achieved.
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Determination of zinc oxide content of mineral medicine Calamine using near-infrared spectroscopy based on MIV and BP-ANN algorithm.
Spectrochimica acta. Part A Molecular and biomolecular spectroscopy, 2017Co-Authors: Xiaodong Zhang, Yangbo Sun, Long Chen, Bisheng Huang, Yu Bai, Keli ChenAbstract:Near-infrared (NIR) spectroscopy has been widely used in the analysis fields of traditional Chinese medicine. It has the advantages of fast analysis, no damage to samples and no pollution. In this research, a fast quantitative model for zinc oxide (ZnO) content in mineral medicine Calamine was explored based on NIR spectroscopy. NIR spectra of 57 batches of Calamine samples were collected and the first derivative (FD) method was adopted for conducting spectral pretreatment. The content of ZnO in Calamine sample was determined using ethylenediaminetetraacetic acid (EDTA) titration and taken as reference value of NIR spectroscopy. 57 batches of Calamine samples were categorized into calibration and prediction set using the Kennard-Stone (K-S) algorithm. Firstly, in the calibration set, to calculate the correlation coefficient (r) between the absorbance value and the ZnO content of corresponding samples at each wave number. Next, according to the square correlation coefficient (r2) value to obtain the top 50 wave numbers to compose the characteristic spectral bands (4081.8-4096.3, 4188.9-4274.7, 4335.4, 4763.6,4794.4-4802.1, 4809.9, 4817.6-4875.4cm-1), which were used to establish the quantitative model of ZnO content using back propagation artificial neural network (BP-ANN) algorithm. Then, the 50 wave numbers were operated by the mean impact value (MIV) algorithm to choose wave numbers whose absolute value of MIV greater than or equal to 25, to obtain the optimal characteristic spectral bands (4875.4-4836.9, 4223.6-4080.9cm-1). And then, both internal cross and external validation were used to screen the number of hidden layer nodes of BP-ANN. Finally, the number 4 of hidden layer nodes was chosen as the best. At last, the BP-ANN model was found to enjoy a high accuracy and strong forecasting capacity for analyzing ZnO content in Calamine samples ranging within 42.05-69.98%, with relative mean square error of cross validation (RMSECV) of 1.66% and coefficient of determination (R2) of 95.75% in internal cross and relative mean square error of prediction (RMSEP) of 1.98%, R2 of 97.94% and ratio of performance to deviation (RPD) of 6.11 in external validation.
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a rapid identification method for Calamine using near infrared spectroscopy based on multi reference correlation coefficient method and back propagation artificial neural network
Applied Spectroscopy, 2017Co-Authors: Yangbo Sun, Long Chen, Bisheng Huang, Keli ChenAbstract:As a mineral, the traditional Chinese medicine Calamine has a similar shape to many other minerals. Investigations of commercially available Calamine samples have shown that there are many fake and inferior Calamine goods sold on the market. The conventional identification method for Calamine is complicated, therefore as a result of the large scale of Calamine samples, a rapid identification method is needed. To establish a qualitative model using near-infrared (NIR) spectroscopy for rapid identification of various Calamine samples, large quantities of Calamine samples including crude products, counterfeits and processed products were collected and correctly identified using the physicochemical and powder X-ray diffraction method. The NIR spectroscopy method was used to analyze these samples by combining the multi-reference correlation coefficient (MRCC) method and the error back propagation artificial neural network algorithm (BP-ANN), so as to realize the qualitative identification of Calamine samples. The accuracy rate of the model based on NIR and MRCC methods was 85%; in addition, the model, which took comprehensive multiple factors into consideration, can be used to identify crude Calamine products, its counterfeits and processed products. Furthermore, by in-putting the correlation coefficients of multiple references as the spectral feature data of samples into BP-ANN, a BP-ANN model of qualitative identification was established, of which the accuracy rate was increased to 95%. The MRCC method can be used as a NIR-based method in the process of BP-ANN modeling.