The depression behavior and mechanism of guar gum on talc-type scheelite flotation were systematically investigated by flotation experiments, adsorption tests, zeta-potential measurements, and infrared spectroscopic a...The depression behavior and mechanism of guar gum on talc-type scheelite flotation were systematically investigated by flotation experiments, adsorption tests, zeta-potential measurements, and infrared spectroscopic analyses. The flotation results for monominerals, mixed minerals, and actual mineral samples indicated that guar gum exhibited much higher selective depression for talc than for scheelite. Bench-scale closed-circuit tests showed that a tungsten concentrate with a WO_3 grade of 51.43% and a WO_3 recovery of 76.18% was obtained. Adsorption tests, zeta-potential measurements, and infrared spectral analyses confirmed that guar gum absorbed more strongly onto the talc surface than onto the scheelite surface because of chemisorption between guar gum and talc. This chemisorption is responsible for the guar gum's highly selective depression for talc and small depression for scheelite. The flotation results provide technical support for talc-type scheelite flotation.展开更多
To the Editor:Central pontine myelinolysis(CPM),a form of osmotic demyelination syndrome(ODS)typically-occurring in the central pons,was first described in alcoholic and malnourished individuals by Adams et al[1]in 19...To the Editor:Central pontine myelinolysis(CPM),a form of osmotic demyelination syndrome(ODS)typically-occurring in the central pons,was first described in alcoholic and malnourished individuals by Adams et al[1]in 1959.ODS is frequently associated with alcohol abuse,liver transplantation,and rapid correction of hyponatremia.[2]The clinical manifestations of CPM are variable,including dysarthria,dysphagia,oculomotor dysfunction,variable degrees of quadriparesis and even locked-in syndrome.addition,some patients may be asymptomatic.The size of myelinolysis in the central pons on brain magnetic resonance imaging(MRI)is not always matched with the severity of clinical symptoms.Previously,a limited number of case reports focued on the magnetic resonance spectroscopy(MRS)findings of CPM.展开更多
基金financially supported by the National Natural Science Foundation of China (No.51404218)the National Key Technology R&D Program (No.2015BAB12B02)the Science and Technology Planning Project of Guangdong Province, China (No.2013B090800016)
文摘The depression behavior and mechanism of guar gum on talc-type scheelite flotation were systematically investigated by flotation experiments, adsorption tests, zeta-potential measurements, and infrared spectroscopic analyses. The flotation results for monominerals, mixed minerals, and actual mineral samples indicated that guar gum exhibited much higher selective depression for talc than for scheelite. Bench-scale closed-circuit tests showed that a tungsten concentrate with a WO_3 grade of 51.43% and a WO_3 recovery of 76.18% was obtained. Adsorption tests, zeta-potential measurements, and infrared spectral analyses confirmed that guar gum absorbed more strongly onto the talc surface than onto the scheelite surface because of chemisorption between guar gum and talc. This chemisorption is responsible for the guar gum's highly selective depression for talc and small depression for scheelite. The flotation results provide technical support for talc-type scheelite flotation.
文摘To the Editor:Central pontine myelinolysis(CPM),a form of osmotic demyelination syndrome(ODS)typically-occurring in the central pons,was first described in alcoholic and malnourished individuals by Adams et al[1]in 1959.ODS is frequently associated with alcohol abuse,liver transplantation,and rapid correction of hyponatremia.[2]The clinical manifestations of CPM are variable,including dysarthria,dysphagia,oculomotor dysfunction,variable degrees of quadriparesis and even locked-in syndrome.addition,some patients may be asymptomatic.The size of myelinolysis in the central pons on brain magnetic resonance imaging(MRI)is not always matched with the severity of clinical symptoms.Previously,a limited number of case reports focued on the magnetic resonance spectroscopy(MRS)findings of CPM.
