Shun Myung Shin

Separation and Recovery of Vanadium from Synthetic Leach Liquor Solutions Containing Iron, Calcium, Sodium, Aluminum, and Manganese by the Solvent Extraction Technique

Solvent extraction and separation of vanadium from other associated metals such as Ca, Na, Fe, Mn, Al from sulfate solutions using various extractants like phosphorus based and amine- based extractants were studied. And the other experimental conditions were optimized as follows: pH influence, extractants influence, 3rd phase studies, extraction equilibrium time, aqueous: organic phase ratios (A:O), water washings followed by sulfuric acid stripping process of metal from loaded organic phase were established. In the present study an analytical instrument, that is, an inductively coupled plasma optimal emission spectrometer (ICP-OES), was used for the vanadium and other metals analysis in aqueous solutions. The calculated separation factors (SFs) are presented and comparisons are made among all the experiments.

Re-manufacture of cobalt-manganese-bromide as a liquid catalyst from spent catalyst containing cobalt generated from petrochemical processes via hydrometallurgy.

Cobalt and manganese have been the subject of individual separation studies because their fields of application are different. However, this study shows that high-value products can be manufactured in the form of a cobalt-manganese-bromide (CMB) liquid catalyst by simultaneously recovering cobalt and manganese. Na-bis-(2,4,4-tri-methyl-pentyl)phosphinic acid was employed in order to manufacture the CMB liquid catalyst from the spent catalyst generated from petroleum chemistry processes. The pH-isotherm, degree of saponification of solvent and separation factor values were investigated. ΔpH50 and separation factor values show that Co and Mn can be separated from impurities such as Mg and Ca. Further, the extraction stages and organic/aqueous ratio isotherms were investigated using counter-current simulation extraction batch tests. To prepare CMB from a loaded organic phase obtained in a stripping study using hydrogen bromide, the Co and Mn were completely stripped and concentrated by a factor of 6 using a 2M hydrogen bromide solution. When compared with manufactured and commercial CMB, the CMB liquid catalyst could be produced by supplying a shortage of Mn in the form of manganese bromide. Finally, the method of manufacture of CMB was subjected to a real pilot plant test.

Reduction of High Nickel-Based Oxide Particles Using Hydrogen Gas

Oxide particles of Fe-77Ni alloy scraps were reduced by hydrogen gas on the effect of temperature and time. The chemical composition of metallic powder was examined by X-ray diffraction (XRD) and FeNi3 alloy was finally obtained with a mean particle size of 10μm.

A study on Zn recovery from other metals in the spent mixed batteries through a sequence of hydrometallurgical processes

ABSTRACT A study on selective separation of Zn from a leaching solution by disposal batteries including various type batteries was carried out to understand the recovery behaviour of Zn in leaching solution. Selective recovery of Zn in leaching solution including Mn, Cd, Cu ion was difficult due to its similar physicochemical behaviour. Experiment results by present leaching solution with 279 µm undersize indicated that the best condition for leaching is 1 M H2SO4, 250 rpm, 5 vol.% H2O2 and 353 K and the leaching efficient of Zn, Co and Mn is approximately 97%, respectively. The exclusive extraction behaviour of Zn by using D2EHPA is indicated that the best conditions for solvent extraction are to be 0.6 M D2EHPA diluted with kerosene, 30% saponification, 298 K, 5-min contact time and three-stage countercurrent extraction, and the O/A ratio 1, respectively. Recovery of Zn was with approximately 99.7% selectively from Mn, Co, Ni, Cd and Li. After scrubbing 5 times by pH 2 modified solution and single stripping experiment by 1.5 M H2SO4, the solution including Zn of 9.0 g/L can be produced. GRAPHICAL ABSTRACT

Ultrasonic-assisted leaching kinetics in aqueous FeCl3-HCl solution for the recovery of copper by hydrometallurgy from poorly soluble chalcopyrite

We studied the ultrasonic effect on the leaching of copper from poorly soluble chalcopyrite (CuFeS2) mineral in aqueous FeCl3 solution. The leaching experiment employed two methods, basic leaching and ultrasonic-assisted leaching, and was conducted under the optimized experimental conditions: a slurry density of 20 g/L in 0.1M FeCl3 reactant in a solution of 0.1M HCl, with an agitation speed of 500 rpm and in the temperature range of 50 to 99 °C. The maximum yield obtained from the optimized basic leaching was 77%, and ultrasonic-assisted leaching increased the maximum copper recovery to 87% under the same conditions of basic leaching. In terms of the leaching mechanism, the overall reaction rate of basic leaching is determined by the diffusion of both the product and ash layers based on a shrinking core model with a constant spherical particle; however, in the case of ultrasonic-assisted leaching, the leaching rate is determined by diffusion of the ash layer only by the removal of sulfur adsorbed on the surface of chalcopyrite mineral.