As clean energy,the microwave is commonly used to pretreat various ores.In this work,the microwave dielectric properties of limonitic laterite ore were measured by resonant cavity perturbation technique and the effect...As clean energy,the microwave is commonly used to pretreat various ores.In this work,the microwave dielectric properties of limonitic laterite ore were measured by resonant cavity perturbation technique and the effects from microwave were systematically investigated.Results indicated that limonitic laterite had high microwave absorbance.After microwave pretreatment,the microstructure of the laterite became less aggregated and more porous and the main phase transformed from goethite to hematite that improved leaching in nitric acid(1.2 kg HNO3/kg ore);Ni,Co,Fe,and Mg extraction ratios were 95.2%,98.1%,1.8%and 15%,respectively,after leaching for 60 min at 200°C and 500 r/min.Furthermore,in the process of goethite to hematite by microwave pretreatment,the nickel-containing mineral is activated,which makes nickel be leached easily.The leaching process has high Ni extraction ratio compared to that without microwave(82%)and conventional pretreatment(90.4%).Therefore,microwave pretreatment of limonitic laterite before nitric acid pressure leaching is an effective way to improve the selectivity and extraction of the leach.展开更多
In this paper we describe a route to produce crystalline Mg（OH）2 nanopowders from serpentinite ore distributed in the Halilovskiy array （Russia, Orenburg region）. An efficient extraction route consisting of treatm...In this paper we describe a route to produce crystalline Mg（OH）2 nanopowders from serpentinite ore distributed in the Halilovskiy array （Russia, Orenburg region）. An efficient extraction route consisting of treatment on serpentinite in 40% HNO3 at 80 ℃followed by NH4OH titration for Mg（OH）2 precipitation was demonstrated. In this study, crystalline Mg（OH）2 nanopowders have been synthesized by solvothermal reaction method using （Mg（NO3）2·6H2O） which were obtained from serpentinite, NH4OH as a precipitator, and hydroxyethylated nonylphenol as surface-active substance. Microstructure and phase composition of samples were investigated employing scanning electron microscopy （SEM） and transmission electron microscopy （TEM）, X-ray phase analysis （XRD）, and inductively coupled plasma optical emission spectroscopy （ICP-OES）. XRD reveals that Mg（OH）2 nanopowder with high purity has the brucite structure. It was found that crystalline Mg（OH）2 nanopowders exclusively consist of lamellar-like structures and the sizes of Mg（OH）2 are 30-265 nm length or width.展开更多
基金Project(51974025)supported by the National Natural Science Foundation of ChinaProject(2018IA055)supported by the International Cooperation Project of Key Research and Development Plan of Yunan Province,ChinaProject(JKY2019-09)supported by State Key Laboratory of Nickel and Cobalt Resources Comprehensive Utilization,China。
文摘As clean energy,the microwave is commonly used to pretreat various ores.In this work,the microwave dielectric properties of limonitic laterite ore were measured by resonant cavity perturbation technique and the effects from microwave were systematically investigated.Results indicated that limonitic laterite had high microwave absorbance.After microwave pretreatment,the microstructure of the laterite became less aggregated and more porous and the main phase transformed from goethite to hematite that improved leaching in nitric acid(1.2 kg HNO3/kg ore);Ni,Co,Fe,and Mg extraction ratios were 95.2%,98.1%,1.8%and 15%,respectively,after leaching for 60 min at 200°C and 500 r/min.Furthermore,in the process of goethite to hematite by microwave pretreatment,the nickel-containing mineral is activated,which makes nickel be leached easily.The leaching process has high Ni extraction ratio compared to that without microwave(82%)and conventional pretreatment(90.4%).Therefore,microwave pretreatment of limonitic laterite before nitric acid pressure leaching is an effective way to improve the selectivity and extraction of the leach.
基金the state on behalf of the Ministry of Education and Science of the Russian Federation of the Agreement (No. 14.577.21.0111 (22 September 2014))The unique identifier of the applied research (No. RFMEFI57714X0111)
文摘In this paper we describe a route to produce crystalline Mg（OH）2 nanopowders from serpentinite ore distributed in the Halilovskiy array （Russia, Orenburg region）. An efficient extraction route consisting of treatment on serpentinite in 40% HNO3 at 80 ℃followed by NH4OH titration for Mg（OH）2 precipitation was demonstrated. In this study, crystalline Mg（OH）2 nanopowders have been synthesized by solvothermal reaction method using （Mg（NO3）2·6H2O） which were obtained from serpentinite, NH4OH as a precipitator, and hydroxyethylated nonylphenol as surface-active substance. Microstructure and phase composition of samples were investigated employing scanning electron microscopy （SEM） and transmission electron microscopy （TEM）, X-ray phase analysis （XRD）, and inductively coupled plasma optical emission spectroscopy （ICP-OES）. XRD reveals that Mg（OH）2 nanopowder with high purity has the brucite structure. It was found that crystalline Mg（OH）2 nanopowders exclusively consist of lamellar-like structures and the sizes of Mg（OH）2 are 30-265 nm length or width.
