scholarly journals Development of a hydrometallurgical process for the recovery of pure alumina from black dross and synthesis of magnesium spinel

2020 ◽  
Vol 9 (2) ◽  
pp. 2568-2577 ◽  
Author(s):  
Thi Thuy Nhi Nguyen ◽  
Si Jeong Song ◽  
Man Seung Lee
Keyword(s):  
Hydrometallurgical Process ◽  
Pure Alumina ◽  
Magnesium Spinel

LEACHING PROPERTIES OF LEAD PASTE IN SPENT LEAD-ACID BATTERY WITH A HYDROMETALLURGICAL PROCESS AT ROOM TEMPERATURE

2013 ◽  
Vol 12 (11) ◽  
pp. 2175-2182 ◽  
Author(s):  
Jiakuan Yang ◽  
Xinfeng Zhu ◽  
Lei Li ◽  
Jianwen Liu ◽  
Ramachandran Vasant Kumar
Keyword(s):  
Room Temperature ◽  
Hydrometallurgical Process ◽  
Lead Acid Battery ◽  
Lead Acid

scholarly journals Hydrometallurgical process for recovery of Zn, Pb, Ga and Ge from Zn refinery residues

2021 ◽  
Vol 31 (2) ◽  
pp. 555-564
Author(s):  
Shuai RAO ◽  
Zhi-qiang LIU ◽  
Dong-xing WANG ◽  
Hong-yang CAO ◽  
Wei ZHU ◽  
...  
Keyword(s):  
Hydrometallurgical Process

scholarly journals Process characterization and analysis of ceramic powder bed fusion

2021 ◽  
Author(s):  
Kevin Florio ◽  
Dario Puccio ◽  
Giorgio Viganò ◽  
Stefan Pfeiffer ◽  
Fabrizio Verga ◽  
...  
Keyword(s):  
High Speed ◽  
Ceramic Powder ◽  
Integrating Sphere ◽  
Alumina Powder ◽  
Powder Bed Fusion ◽  
Single Track ◽  
Ceramic Powders ◽  
Pure Alumina ◽  
Powder Bed ◽  
Melt Pool

AbstractPowder bed fusion (PBF) of ceramics is often limited because of the low absorptance of ceramic powders and lack of process understanding. These challenges have been addressed through a co-development of customized ceramic powders and laser process capabilities. The starting powder is made of a mix of pure alumina powder and alumina granules, to which a metal oxide dopant is added to increase absorptance. The performance of different granules and process parameters depends on a large number of influencing factors. In this study, two methods for characterizing and analyzing the PBF process are presented and used to assess which dopant is the most suitable for the process. The first method allows one to analyze the absorptance of the laser during the melting of a single track using an integrating sphere. The second one relies on in-situ video imaging using a high-speed camera and an external laser illumination. The absorption behavior of the laser power during the melting of both single tracks and full layers is proven to be a non-linear and extremely dynamic process. While for a single track, the manganese oxide doped powder delivers higher and more stable absorptance. When a full layer is analyzed, iron oxide-doped powder is leading to higher absorptance and a larger melt pool. Both dopants allow the generation of a stable melt-pool, which would be impossible with granules made of pure alumina. In addition, the present study sheds light on several phenomena related to powder and melt-pool dynamics, such as the change of melt-pool shape and dimension over time and powder denudation effects.

scholarly journals Leaching and solvent extraction purification of zinc from Mehdiabad complex oxide ore

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Faraz Soltani ◽  
Hossna Darabi ◽  
Reza Aram ◽  
Mahdi Ghadiri
Keyword(s):  
Solvent Extraction ◽  
Environmental Pollution ◽  
Central Composite Design ◽  
Complex Oxide ◽  
Hydrometallurgical Process ◽  
Purification Process ◽  
Optimum Conditions ◽  
Leaching Experiments ◽  
Central Composite ◽  
Sulphuric Acid Concentration

AbstractAn integrated hydrometallurgical process was used for the zinc leaching and purification from a zinc ore containing 9.75 wt% zinc. The zinc minerals in the ore were hemimorphite, willemite, and calcophanite. Main gangue minerals were quartz, goethite, hematite, and calcite. Central composite design (CCD) method was used to design leaching experiments and the optimum conditions were found as follows: 30% of solid fraction, 22.05% sulphuric acid concentration, and the leaching temperature of 45 °C. The PLS containing 35.07 g/L zinc, 3.16 g/L iron, and 4.58 g/L manganese impurities was produced. A special purification process including Fe precipitation and Zn solvent extraction was implemented. The results showed that after precipitation of iron, Zn extraction of 88.5% was obtained with the 2 stages extraction system composed of 30 vol% D2EHPA as extractant. The overall Zn recovery from the ore was 71.44%. Therefore, an appropriate solution containing 16.6 g/L Zn, 0.05 g/L Fe, and 0.11 g/L Mn was prepared for the electro-winning unit without using the roasting and calcination steps (conventional method), which result in environmental pollution.

Silicon Carbide Die Attach Scheme for 500°C Operation

2000 ◽  
Vol 622 ◽  
Author(s):  
Liang-Yu Chen ◽  
Gary W. Hunter ◽  
Philip G. Neudeck
Keyword(s):  
Silicon Carbide ◽  
High Temperature ◽  
Electrical Resistance ◽  
Room Temperature ◽  
Semiconductor Devices ◽  
Single Crystal Silicon ◽  
Film Material ◽  
Crystal Silicon ◽  
Pure Alumina ◽  
Die Attach

ABSTRACTSingle crystal silicon carbide (SiC) has such excellent physical, chemical, and electronic properties that SiC based semiconductor electronics can operate at temperatures in excess of 600°C well beyond the high temperature limit for Si based semiconductor devices. SiC semiconductor devices have been demonstrated to be operable at temperatures as high as 600°C, but only in a probe-station environment partially because suitable packaging technology for high temperature (500°C and beyond) devices is still in development. One of the core technologies necessary for high temperature electronic packaging is semiconductor die-attach with low and stable electrical resistance. This paper discusses a low resistance die-attach method and the results of testing carried out at both room temperature and 500°C in air. A 1 mm2 SiC Schottky diode die was attached to aluminum nitride (AlN) and 96% pure alumina ceramic substrates using precious metal based thick-film material. The attached test die using this scheme survived both electronically and mechanically performance and stability tests at 500°C in oxidizing environment of air for 550 hours. The upper limit of electrical resistance of the die-attach interface estimated by forward I-V curves of an attached diode before and during heat treatment indicated stable and low attach-resistance at both room-temperature and 500°C over the entire 550 hours test period. The future durability tests are also discussed.

Deposition of inorganic bronze coatings over ceramic foams

2005 ◽  
Vol 20 (5) ◽  
pp. 1207-1215 ◽  
Author(s):  
M. Mann ◽  
G.E. Shter ◽  
G.S. Grader
Keyword(s):  
Intermediate Layer ◽  
Hydrogen Reduction ◽  
Tungsten Bronze ◽  
Impregnation Method ◽  
Ceramic Surface ◽  
Pure Alumina ◽  
Ceramic Foams ◽  
External Agent ◽  
Nacl Concentration ◽  
General Basis

A method for applying conductive inorganic tungsten bronze (NaxWO3) coatings over ceramic foams is presented. The general basis of bronze coating involves an intermediate layer between the ceramic surface and the redox external agent (liquid or gas phase). The intermediate layer is a multifunctional element and its function depends on the agents involved in redox reaction. The bronze film is formed either on the intermediate layer or in place of it. The initial melt included Na2WO4, WO3, and NaCl. The reticulated ceramic foams, made from pure alumina (Al2O3), were prepared by a standard impregnation method. In all depositions, the temperature was above the melting point of the Na2WO4/WO3 system. The effect of NaCl content on the final coating properties was investigated in the 10–40 mol% range. The best results were obtained with hydrogen reduction of 40% NaCl in the melt. The bronze crystals size in the coating was 0.8–1.6 μm. The bronze layer was continuous throughout the foam. The obtained coating has a bright yellow-gold color, consistent with a stoichiometric parameter value (x) of 0.85–0.95. The resistivity of coated foams decreased from above 12 Ω mm to below 1 Ω mm when the NaCl concentration in the melts increased from 10% to 40%, respectively, due to improved continuity of the bronze crystals. These highly conductive, bronze-coated alumina foams, can potentially serve as high-temperature electrodes in aggressive conditions.

Sign in / Sign up

Export Citation Format

Share Document