The goal of this work is the separation and recovery of platinum and palladium from spent catalyst. The recovery consisted of separating the maximum amount of platinum and palladium from catalysts and changing them into usable forms. The petroleum and petrochemical units use Pt and Pd catalyst for reactions such as reforming and hydrogenation. Because these materials contain valuable metals...

UNLABELLED Reduction of surface plasmon-polariton losses due to their scattering on metal surface roughness still remains a challenge in the fabrication of plasmonic devices for nanooptics. To achieve smooth silver films, we study the dependence of surface roughness on the evaporation temperature in a physical vapor deposition process. At the deposition temperature range 90 to 500 K, the mismat...

TiO2 production is a key part of Ti metallurgy and recycling, the process itself has turned out to be energy-consuming material-consuming. New technologies are needed utilize complex ores, such as ilmenite, reduce carbon footprint extraction. Ammonium sulfate roasting been revealed an efficient way carry phase transformations minerals. A low-temperature sulfation approach was studied chemically...

Optimization of manganese ore leaching process from North Central Timor, Indonesia has been investigated. The final product the was MnSO4. Variables that were optimized during volume H2O2, reaction temperature, and time. products characterized by FTIR, powder-XRD, XRF, AAS. Experimental data shows optimum conditions for 50 mL H2SO4 4 M, 25 H2O2 2 in which done at room temperature two hours. Thi...

This paper studies stability for parametric mathematical programs with geometric constraints. We show that, under the no nonzero abnormal multiplier constraint qualification and the second-order growth condition or second-order sufficient condition, the locally optimal solution mapping and stationary point mapping are nonempty-valued and continuous with respect to the perturbation parameter and...

Many engineering optimization problems involve a special kind of discrete variable that can be represented by a number, but this representation has no significance. Such variables arise when a decision involves some situation like a choice from an unordered list of categories. This has two implications: The standard approach of solving problems with continuous relaxations of discrete variables ...

Sulphate leaching losses may reduce the long-term possibility of maintaining the S supply of crops in low input farming systems. Sulphate leaching and S balances were investigated in an organic dairy/crop rotation (barley [Hordeum vulgare] → grass-clover [Lolium perenne/Trifolium repens] → grass-clover → barley/pea [Pisum arvénse] → winter wheat [Tritucum aestivum] → fodder beet [Beta vulgaris]...

Leaching studies of a sludge produced by the physico-chemical treatment of wastewaters generated by a Ni/Cr plating plant were carried out in both sulphuric acid and ammoniacal media aiming to decide which of them would be the best treatment for this kind of waste material. The dissolution behaviour of some metals (Cu, Ni, Cr and Zn) was studied in order to assure the best metal recovery condit...

Batch leaching tests were employed to investigate the leaching potential of arsenic (As) and selenium (Se) from two fly ash samples. The effect of pH and solid-to-liquid (S/L) ratio on As and Se leaching was examined in this preliminary study. Maximum As leaching occurred at pH 7-8, and soluble As concentration slightly increased with decrease of S/L ratio. Se displayed consistently increasing ...