Ultrasonic arc spray atomization (UASA) method was used to prepare high-melting-point, immiscible AgNi15 (mass fraction, %) composite particles. Sieving was used to determine the size distribution of the AgNi15 partic...Ultrasonic arc spray atomization (UASA) method was used to prepare high-melting-point, immiscible AgNi15 (mass fraction, %) composite particles. Sieving was used to determine the size distribution of the AgNi15 particles. The morphology, rapidly solidified structure and metastable solution expansion of the AgNi15 particles were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS), respectively. The results show that the AgNi15 composite particles are spherical and well-dispersed, and the mass fractions of the particles with diameters <74μm and <55 μm are 99.5% and 98%, respectively. The rapidly solidified structure of the AgNi15 particles consists of spherical nickel-richβ(Ni)-phase particles dispersed throughout a silver-richα(Ag)-phase matrix andα(Ag)-phase nanoparticles dispersed throughout largerβ(Ni)-phase particles. The silver and nickel in the AgNi15 particles form a reciprocally extended metastable solution, and the solid solubility of nickel in the silver matrix at room temperature is in the range of 0.16%?0.36% (mole fraction).展开更多
Spray drying is an important continuous industrial process for drying pumpable liquid formulations irrespective of their heat sensitivity, rheology, solids content and processing rate. Furthermore spray drying has the...Spray drying is an important continuous industrial process for drying pumpable liquid formulations irrespective of their heat sensitivity, rheology, solids content and processing rate. Furthermore spray drying has the capability through drying chamber design, plant layout and mode of operation to produce dried products of specific particulate size and morphology. These are important aspects when spray drying technology is applied to the needs of customized powder manufacture. There are many examples in industry where spray dried powders have to meet stringent specifications set by such factors as end-product powder quality standards dictated by global competition,dry raw material characteristics required for optimum downstream processing, and dry materials handling to comply with environmental, health and safety issues. Spray drying is no longer regarded just as a convective industrial drying concept, but also as an integral part of modern manufacturing practices applying powder technology. This paper reviews the aspects of spray dryer design and operation for consideration when customized powder manufacture is involved.展开更多
For the low-grade copper sulfide ores with 0.99% of copper, of which 41.5% was primary copper sulfide, and 54.5% was secondary copper sulfide, well-controlled column bioleaching on a novel equipment was carried out to...For the low-grade copper sulfide ores with 0.99% of copper, of which 41.5% was primary copper sulfide, and 54.5% was secondary copper sulfide, well-controlled column bioleaching on a novel equipment was carried out to investigate the optimal conditions of pre-leaching, particle sizes of ores, temperature, spray intensity and strain consortium. Results show that copper extraction of 91.11% can be obtained after 90 d with the optimal p H value of pre-leaching of 0.8; the p H values of pre-leaching significantly affect the final copper extractions. Copper extractions of 93.11%, 91.04% and 80.45% can be obtained for the bioleaching of ores with particles size of 5-8 mm, 5-15 mm and 5-20 mm, respectively. Copper extractions are 83.77% and 91.02% for bioleaching under the conditions of room temperature and 35 oC. Copper extractions are 77.25%, 85.45% and 91.12% for the bioleaching when flow rate of spray was 5 L/（h·m2）, 10 L/（h·m2） and 15 L/（h·m2）, respectively. Additionally, the strain consortium C3 is the best among the four strain consortia in bioleaching. By considering the energy consumption, the optimal conditions of bioleaching in this work are determined as p H of pre-leaching of 0.8, particles size of 5-15 mm, temperature of 35 ℃, spray intensity of 15 L/（h·m2）, and strain consortium C3.展开更多
基金Project(2009CC010)supported by the Application Basic Research Foundation of Yunnan Province,ChinaProject(51264037)supported by the National Natural Science Foundation of China
文摘Ultrasonic arc spray atomization (UASA) method was used to prepare high-melting-point, immiscible AgNi15 (mass fraction, %) composite particles. Sieving was used to determine the size distribution of the AgNi15 particles. The morphology, rapidly solidified structure and metastable solution expansion of the AgNi15 particles were analyzed by scanning electron microscopy (SEM), X-ray diffraction (XRD) and energy dispersive spectroscopy (EDS), respectively. The results show that the AgNi15 composite particles are spherical and well-dispersed, and the mass fractions of the particles with diameters <74μm and <55 μm are 99.5% and 98%, respectively. The rapidly solidified structure of the AgNi15 particles consists of spherical nickel-richβ(Ni)-phase particles dispersed throughout a silver-richα(Ag)-phase matrix andα(Ag)-phase nanoparticles dispersed throughout largerβ(Ni)-phase particles. The silver and nickel in the AgNi15 particles form a reciprocally extended metastable solution, and the solid solubility of nickel in the silver matrix at room temperature is in the range of 0.16%?0.36% (mole fraction).
文摘Spray drying is an important continuous industrial process for drying pumpable liquid formulations irrespective of their heat sensitivity, rheology, solids content and processing rate. Furthermore spray drying has the capability through drying chamber design, plant layout and mode of operation to produce dried products of specific particulate size and morphology. These are important aspects when spray drying technology is applied to the needs of customized powder manufacture. There are many examples in industry where spray dried powders have to meet stringent specifications set by such factors as end-product powder quality standards dictated by global competition,dry raw material characteristics required for optimum downstream processing, and dry materials handling to comply with environmental, health and safety issues. Spray drying is no longer regarded just as a convective industrial drying concept, but also as an integral part of modern manufacturing practices applying powder technology. This paper reviews the aspects of spray dryer design and operation for consideration when customized powder manufacture is involved.
基金Projects(51374248,51320105006) supported by National Natural Science Foundation of ChinaProject(NCET-13-0595) supported by the Program for New Century Excellent Talents in University,ChinaProject(2014T70692) supported by the China Postdoctoral Science Foundation
文摘For the low-grade copper sulfide ores with 0.99% of copper, of which 41.5% was primary copper sulfide, and 54.5% was secondary copper sulfide, well-controlled column bioleaching on a novel equipment was carried out to investigate the optimal conditions of pre-leaching, particle sizes of ores, temperature, spray intensity and strain consortium. Results show that copper extraction of 91.11% can be obtained after 90 d with the optimal p H value of pre-leaching of 0.8; the p H values of pre-leaching significantly affect the final copper extractions. Copper extractions of 93.11%, 91.04% and 80.45% can be obtained for the bioleaching of ores with particles size of 5-8 mm, 5-15 mm and 5-20 mm, respectively. Copper extractions are 83.77% and 91.02% for bioleaching under the conditions of room temperature and 35 oC. Copper extractions are 77.25%, 85.45% and 91.12% for the bioleaching when flow rate of spray was 5 L/（h·m2）, 10 L/（h·m2） and 15 L/（h·m2）, respectively. Additionally, the strain consortium C3 is the best among the four strain consortia in bioleaching. By considering the energy consumption, the optimal conditions of bioleaching in this work are determined as p H of pre-leaching of 0.8, particles size of 5-15 mm, temperature of 35 ℃, spray intensity of 15 L/（h·m2）, and strain consortium C3.
