The Anjing Hitam Pb-Zn deposit in northern Sumatra(Indonesia) is one of the largest Pb-Zn deposits in the region. The stratiform orebodies are mainly hosted in the middle member of the Carboniferous–Permian Kluet For...The Anjing Hitam Pb-Zn deposit in northern Sumatra(Indonesia) is one of the largest Pb-Zn deposits in the region. The stratiform orebodies are mainly hosted in the middle member of the Carboniferous–Permian Kluet Formation of the Tapanuli Group. Mineral paragenesis and crosscutting relationships suggest a two-stage Pb-Zn mineralization:(I) sedimentary and(Ⅱ) hydrothermal mineralization. Ore-related calcite from both stages Ⅰ and Ⅱ contains mainly liquid-and gas-liquid two-phase-type fluid inclusions(FI). For stage I ore-forming fluids, FI homogenization temperatures(T_h) are 105 to 199 oC, and the salinities are 9.6 wt.% to 16.6 wt.% NaCleqiv, reflecting low temperature and medium-low salinity; whereas in stage Ⅱ, the T_h(206 to 267 oC) and salinity(19.0 wt.% to 22.5 wt.% NaCleqiv) are considerably higher. Fluid inclusion and C-O isotope characteristics suggest that the stage I ore-forming fluids were mainly derived from a mixture of seawater and magmatic fluids(probably from deep-lying plutons), whereas the stage Ⅱ ore-forming fluids were likely magmatic-derived with wall rock input. We propose that the Anjing Hitam deposit was a Carboniferous exhalative sedimentary(SEDEX) deposit overprinted by the Pleistocene vein-style magmatic-hydrothermal mineralization.展开更多
Indonesia,with its vast forested regions,has experienced significant deforestation,adversely affecting the wood industry.As a result,alternative sources of lignocellulosic biomass are required to mitigate this impact....Indonesia,with its vast forested regions,has experienced significant deforestation,adversely affecting the wood industry.As a result,alternative sources of lignocellulosic biomass are required to mitigate this impact.Among the abundant lignocellulosic raw materials in Indonesia,particularly in Sumatra,bamboo stands out as a promising substitute.Bamboo is a highly versatile resource,suitable for various applications,including its use as a composite raw material to replace traditional wood-based products.This research work aimed to investigate and evaluate the characteristics—morphology,anatomy,physical and mechanical properties,chemical composition,starch content,and natural resistance—of three bamboo species:hitam bamboo(Gigantochloa atroviolacea),betung bamboo(Dendrocalamus asper),and belangke bamboo(Gigantochloa pruriens),as well as their suitability for the production of oriented strand boards(OSB).The lumen values of the bamboo samples ranged between 10 and 15μm,with hitam and betung bamboo exhibitingmedium-thickness cell walls(>5μm).Based on fiber dimension analysis,belangke,and betung bamboo are classified within quality class II,whereas hitam bamboo falls into class Ⅰ.The highest recorded tensile,shear,and compressive mechanical strength values were observed at the tips of hitam bamboo,measuring 563.43 MPa,15 MPa,and 6.87 kN/mm^(2),respectively.The bamboo samples underwent three different treatments:(1)immersion in water for 24 h,(2)autoclaving at 120℃ for 1 h,and(3)a control group with no treatment.OSB panels were produced with dimensions of 20 cm×20 cm×1 cm(length×width×thickness)using isocyanate adhesive and conditioned for 14 days.The physical and mechanical properties of the OSBs were evaluated based on the Japan Industrial Standard(JIS)A5908:2003 and theCanadian StandardsAssociation(CSA)0437.0:2011 criteria.The density of the laboratory-produced OSB panels ranged from 0.60 to 0.73 g/cm^(3),moisture content varied from5.4% to 8.1%,water absorption ranged between 31.6% and 45.8%,and thickness swelling was recorded at 5.1% to 16.3%.The modulus of elasticity(MOE)ranged from2745.1 to 7813.3 MPa,themodulus of rupture(MOR)from 30.8 to 58.8MPa,and internal bonding(IB)from 0.27 to 0.47 MPa.Overall,all OSB panels produced in this study met the specifications outlined in JIS A 5908(2003)and CSA 0437.0(2011),demonstrating the viability of these bamboo species as raw materials for OSB production.展开更多
基金financially supported by the National Basic Research Program of China (No. 2014CB440901)
文摘The Anjing Hitam Pb-Zn deposit in northern Sumatra(Indonesia) is one of the largest Pb-Zn deposits in the region. The stratiform orebodies are mainly hosted in the middle member of the Carboniferous–Permian Kluet Formation of the Tapanuli Group. Mineral paragenesis and crosscutting relationships suggest a two-stage Pb-Zn mineralization:(I) sedimentary and(Ⅱ) hydrothermal mineralization. Ore-related calcite from both stages Ⅰ and Ⅱ contains mainly liquid-and gas-liquid two-phase-type fluid inclusions(FI). For stage I ore-forming fluids, FI homogenization temperatures(T_h) are 105 to 199 oC, and the salinities are 9.6 wt.% to 16.6 wt.% NaCleqiv, reflecting low temperature and medium-low salinity; whereas in stage Ⅱ, the T_h(206 to 267 oC) and salinity(19.0 wt.% to 22.5 wt.% NaCleqiv) are considerably higher. Fluid inclusion and C-O isotope characteristics suggest that the stage I ore-forming fluids were mainly derived from a mixture of seawater and magmatic fluids(probably from deep-lying plutons), whereas the stage Ⅱ ore-forming fluids were likely magmatic-derived with wall rock input. We propose that the Anjing Hitam deposit was a Carboniferous exhalative sedimentary(SEDEX) deposit overprinted by the Pleistocene vein-style magmatic-hydrothermal mineralization.
基金supported by the TALENTA research grant scheme of the“Kolaborasi Nasional Penerima Dana Hibah WCU(World Class University)Universitas Sumatera Utara”in the year 2022(Number:353/UN5.2.3.1/PPM/KP-TALENTA/2022)supported by the project“Development,Exploitation Properties and Application of Eco-Friendly Wood-Based Composites from Alternative Lignocellulosic Raw Materials”,Project No.HHC-b-1290/19.10.2023,carried out at the University of Forestry,Sofia,Bulgaria.
文摘Indonesia,with its vast forested regions,has experienced significant deforestation,adversely affecting the wood industry.As a result,alternative sources of lignocellulosic biomass are required to mitigate this impact.Among the abundant lignocellulosic raw materials in Indonesia,particularly in Sumatra,bamboo stands out as a promising substitute.Bamboo is a highly versatile resource,suitable for various applications,including its use as a composite raw material to replace traditional wood-based products.This research work aimed to investigate and evaluate the characteristics—morphology,anatomy,physical and mechanical properties,chemical composition,starch content,and natural resistance—of three bamboo species:hitam bamboo(Gigantochloa atroviolacea),betung bamboo(Dendrocalamus asper),and belangke bamboo(Gigantochloa pruriens),as well as their suitability for the production of oriented strand boards(OSB).The lumen values of the bamboo samples ranged between 10 and 15μm,with hitam and betung bamboo exhibitingmedium-thickness cell walls(>5μm).Based on fiber dimension analysis,belangke,and betung bamboo are classified within quality class II,whereas hitam bamboo falls into class Ⅰ.The highest recorded tensile,shear,and compressive mechanical strength values were observed at the tips of hitam bamboo,measuring 563.43 MPa,15 MPa,and 6.87 kN/mm^(2),respectively.The bamboo samples underwent three different treatments:(1)immersion in water for 24 h,(2)autoclaving at 120℃ for 1 h,and(3)a control group with no treatment.OSB panels were produced with dimensions of 20 cm×20 cm×1 cm(length×width×thickness)using isocyanate adhesive and conditioned for 14 days.The physical and mechanical properties of the OSBs were evaluated based on the Japan Industrial Standard(JIS)A5908:2003 and theCanadian StandardsAssociation(CSA)0437.0:2011 criteria.The density of the laboratory-produced OSB panels ranged from 0.60 to 0.73 g/cm^(3),moisture content varied from5.4% to 8.1%,water absorption ranged between 31.6% and 45.8%,and thickness swelling was recorded at 5.1% to 16.3%.The modulus of elasticity(MOE)ranged from2745.1 to 7813.3 MPa,themodulus of rupture(MOR)from 30.8 to 58.8MPa,and internal bonding(IB)from 0.27 to 0.47 MPa.Overall,all OSB panels produced in this study met the specifications outlined in JIS A 5908(2003)and CSA 0437.0(2011),demonstrating the viability of these bamboo species as raw materials for OSB production.
