Evaluation of leaching characteristic and kinetic study of lithium from lithium aluminum silicate glass-ceramics by NaOH.

The behavior and mechanism of Li leaching from lithium aluminum silicate glass-ceramics which can be used as a secondary source of Li using aqueous NaOH solution was investigated. The Li leaching efficiency is increased with increasing concentration of NaOH, specific surface area, and reaction temperature. When leached under optimum conditions, 2 mol/L NaOH, 53 µm particle undersize, 1:10 solid/liquid ratio, 250 r/min stirring speed, 100°C reaction temperature, 12 hr, the Li leaching efficiency was approximately 70%. However, when the leaching experiment was performed for 48 hr, the concentration of Li+ ions contained in the leach liquor decreased from 1160 to 236 mg/L. To investigate the origin of this phenomenon, the obtained leach residue was analyzed by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. These analyses show that zeolite was formed around the lithium aluminum silicate glass-ceramics, which affected the leaching of by adsorbing Li+ ions. In addition, using the shrinking-core model and the Arrhenius equation, the leaching reaction with NaOH was found to depends on the chemical reaction of the two reactants, with a higher than 41.84 kJ/mol of the activation energy.

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

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.

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.

Severe sleep apnea syndrome and tonsillar: hyperplasia in an adult / Síndrome de apnéia do sono e hiperplasia amigdaliana

Relatamos um caso de síndrome de apnéia do sono tipo obstrutivo (SASO) severa, em adulto do sexo feminino, associada a hiperplasia amigdaliana, com documentaçao de polissonografia e cefalometria, pré e pós-cirúrgica. Polissonografia pré-opeatória evidenciou índice de apnéia + hipopnéia (RDI), 109,2/h; apnéia mais longa atingindo 64 s; saturaçao de oxigênio mínimo de 40 por cento ; reduçao acentuada de estágio REM e ausência de estágios 3 e 4; intensa fragmentaçao do sono com aumento do número de despertares e movimentos corpóreos. Cefalometria mostrou aumento marcado do volume amigdaliano, com consequente reduçao do espaço aéreo posterior (2,21 mm). Os mesmos exames realizados 4 meses após amigdalectomia e uvulopalatofaringoplastia evidenciaram remissao do quadro, com índices polissonográficos nos limites da normalidade. Cefalometria mostrou dimensao adequada do espaço aéreo posterior (12,22mm)