scholarly journals The Improvement of Platinum Recovery Ratio in the Recycling Process Using “Dry Aqua Regia”

2019 ◽  
Vol 83 (7) ◽  
pp. 250-255
Author(s):  
Akihiro Yoshimura ◽  
Yasunari Matsuno
Keyword(s):  
Recovery Ratio ◽  
Recycling Process ◽  
Aqua Regia ◽  
Platinum Recovery

scholarly journals Fundamental Study of Palladium Recycling Using “Dry Aqua Regia” Considering the Recovery from Spent Auto-catalyst

2021 ◽  
Author(s):  
Akihiro Yoshimura ◽  
Shunta Tochigi ◽  
Yasunari Matsuno
Keyword(s):  
Potassium Chloride ◽  
Platinum Group Metals ◽  
Recycling Process ◽  
Fundamental Study ◽  
Aqua Regia ◽  
Sodium Chloride Solutions ◽  
Pure Compounds ◽  
The Difference ◽  
Solid Liquid ◽  
Solid Liquid Separation

AbstractIn this research, a recycling process for palladium using “dry aqua regia,” which consists of iron(III) chloride–potassium chloride, was proposed. Palladium was dissolved in “dry aqua regia,” and the dissolved palladium was recovered by leaching with potassium chloride solution with added ammonium chloride and nitric acid. Palladium was almost completely dissolved in 3 h at 600 K, and the recovery ratio of dissolved palladium was up to 80%. In addition, the dissolution of palladium in coexistence with platinum and the dissolution of platinum-palladium alloy by “dry aqua regia” were also tested. The dissolved palladium and platinum were separated and recovered by solid–liquid separation technique using the difference in solubility of their compounds in potassium chloride and sodium chloride solutions. As a result, pure compounds of each element were recovered. This result suggested the possibility of using “dry aqua regia” for the separation of platinum-group metals. Graphical Abstract

scholarly journals Platinum Recovery from Spent CCR Platforming Catalyst with Oxalic Acid and Aqua Regia Leaching

2020 ◽  
Vol 722 ◽  
pp. 012077
Author(s):  
Yuliusman ◽  
L P D I Prawira ◽  
A R Nafisah ◽  
K S Amananti ◽  
M P Ayu ◽  
...  
Keyword(s):  
Oxalic Acid ◽  
Aqua Regia ◽  
Platinum Recovery

TEM observations of surface-step and hole-edge faceting in acid-etched and annealed MgO thin foils

1993 ◽  
Vol 51 ◽  
pp. 1134-1135
Author(s):  
Simon King ◽  
C. Barry Carter
Keyword(s):  
Marked Contrast ◽  
Aqua Regia ◽  
Surface Step ◽  
Smoke Particle ◽  
Hole Edge ◽  
Thin Foils ◽  
Surface Steps ◽  
Unit Cells ◽  
Reflection Electron Microscopy ◽  
Similar Preparation

Surface-steps formed during the cleavage of MgO on {100} planes, the smaller steps of which may be of atomic height, have been observed in Reflection-Electron Microscopy investigations to be accurately aligned along <001> directions. Steps of atomic height also have been identified on MgO smoke-particle platelets; these steps may be curved or straight, with the straight steps showing evidence for faceting along <001>. Reference also is made to faceting along <011> and <012> directions. Straight steps ∼2 unit cells high, with edges along <100> also have been imaged by High-Resolution Profile-Imaging at the peripheries of MgO smoke microcubes. After etching in aqua-regia and annealing in air, however, high densities of “large” steps several unit cells high, as well as numerous holes, are formed. It is faceting in these foils that is reported here.As can be seen in fig 1, obvious faceting of the surface-step traces is extremely rare in these foils, in marked contrast to substrates such as LaAlO3 and SrTiO3, on which surface-step traces facet readily after a similar preparation treatment.

Long-Term Stable Metal Organic Framework (MOF) Based Mixed Matrix Membranes for Ultrafiltration

2020 ◽  
Author(s):  
Muayad Al-shaeli ◽  
Stefan J. D. Smith ◽  
Shanxue Jiang ◽  
Huanting Wang ◽  
Kaisong Zhang ◽  
...  
Keyword(s):  
Contact Angle ◽  
Water Contact Angle ◽  
Mixed Matrix Membranes ◽  
Recovery Ratio ◽  
Mixed Matrix ◽  
Water Contact ◽  
Membrane Performance ◽  
Metal Organic ◽  
Matrix Membranes

<p>In this study, novel <a>mixed matrix polyethersulfone (PES) membranes</a> were synthesized by using two different kinds of metal organic frameworks (MOFs), namely UiO-66 and UiO-66-NH<sub>2</sub>. The composite membranes were characterised by SEM, EDX, FTIR, PXRD, water contact angle, porosity, pore size, etc. Membrane performance was investigated by water permeation flux, flux recovery ratio, fouling resistance and anti-fouling performance. The stability test was also conducted for the prepared mixed matrix membranes. A higher reduction in the water contact angle was observed after adding both MOFs to the PES and sulfonated PES membranes compared to pristine PES membranes. An enhancement in membrane performance was observed by embedding the MOF into PES membrane matrix, which may be attributed to the super-hydrophilic porous structure of UiO-66-NH<sub>2</sub> nanoparticles and hydrophilic structure of UiO-66 nanoparticles that could accelerate the exchange rate between solvent and non-solvent during the phase inversion process. By adding the MOFs into PES matrix, the flux recovery ratio was increased greatly (more than 99% for most mixed matrix membranes). The mixed matrix membranes showed higher resistance to protein adsorption compared to pristine PES membranes. After immersing the membranes in water for 3 months, 6 months and 12 months, both MOFs were stable and retained their structure. This study indicates that UiO-66 and UiO-66-NH<sub>2</sub> are great candidates for designing long-term stable mixed matrix membranes with higher anti-fouling performance.</p>

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