Producing High Purity Nickel Metal Powder from Nickel Wastes through Acidic Leaching by Sulfuric Acid

Nickel has found increasing application in electronic, automobilemanufacturing, plating, and metal industries and so on. Producing highquality metal powders to satisfy increasing demand for advanced materialsis of very high importance. There are a few numbers of standard powderproduction techniques. An acidic leaching has been applied in presentresearch. Sulfuric acid has been used to leach nickel wastes of platingindustry. To produce nickel oxide powder furnaces with no protectingatmosphere and to produce pure nickel powder, tube furnace with hydrogenatmosphere has been applied. Variables performed in the research aretime, density of sulfuric acid, and amount of hydrogen peroxide. Toanalyze powders produced, EDS element analysis and to determine size ofpowder particles, SEM has been applied. It was shown by the results thatthe highest amount of nickel dissolution in sulfuric acid (98%) has takenplace during one hour and there is a direct relationship between hydrogenperoxide amount and nickel dissolution in sulfuric acid

Microstructural characterization, mechanical and tribological properties of ZC71 hybrid composite reinforced with SiC and MWCNT

In the present study, the influences of different SiC addition, MWCNTs and various SiC particle sizes on the structural, mechanical and tribological properties of ZC71 alloys were studied. The results revealed that the proper amount/size of SiC particles with the addition of MWCNTs had a considerable effect on the microstructural alteration, and mechanical and tribological properties of the ZC71 alloy. The Vickers hardness values of the ZC71 alloy improved with the addition of MWCNT and SiC. The UTS (216 MPa) and El.% (6.95 %) were achieved in the ZC71-5%SiC(15µm)-0.5%MWCNT. The cast ZC71 alloy showed brittle fracture with some quasi-cleavage characterizations. However, by adding 5% SiC(15 µm) and 0.5% MWCNT, the fracture mode changed to ductile fracture. The wear results showed that the ZC71-5%SiC-0.5%MWCNT hybrid composite had the highest wear resistance with the lowest friction coefficient and wear rate. Examination on the worn surface of the ZC71-5%SiC-0.5%MWCNT hybrid composite showed mild abrasion as the governing wear mechanism.%2</jats:p