Floatability of rare earth phosphors from waste fluorescent lamps

Hirajima, Tsuyoshi; Bissombolo, Abel; Sasaki, Keiko; Nakayama, Kazunori; Hirai, Hisao; Tsunekawa, Masami

doi:10.1016/j.minpro.2005.05.002

Cited by 73 publications

(34 citation statements)

References 17 publications

(18 reference statements)

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“…The median and characteristic particle sizes in the cumulative weight distribution were 29.00 ± 1.96 μm and 38.28 ± 2.14 μm, respectively. Hirajima et al (2005) reported that the median particle size of phosphor powder present in new fluorescent lamps was 14.0 μm, which is smaller than that found here [25]. Phosphor powder was recovered using mechanical screen separation during recycling of spent fluorescent lamps, so the powder contained impurities, such as fine glass powder.…”

Section: Characteristics Of Phosphor Powdermentioning

confidence: 60%

Evaluation of Energy Consumption in the Mercury Treatment of Phosphor Powder from Spent Fluorescent Lamps Using a Thermal Process

Choi

Rhee

2017

Sustainability

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Abstract:In a pilot-plant-scale thermal mercury treatment of phosphor powder from spent fluorescent lamps, energy consumption was estimated to control mercury content by the consideration of reaction kinetics. Mercury content was analyzed as a function of treatment temperature and time. The initial mercury content of the phosphor powder used in the thermal process was approximately 3500 mg/kg. The target mercury content in the phosphor powder thermal process of the phosphor powder was 5 mg/kg or less at 400 • C or higher because the target mercury content was recommended by Minamata Convention and Basel Convention. During thermal processing, the reaction rate was represented by a first order reaction with the Arrhenius equation. The reaction rate constant increased with temperature from 0.0112 min −1 at 350 • C to 0.0558 min −1 at 600 • C. The frequency factor was 2.51 min −1 , and the activation energy was 6509.11 kcal/kg. Reaction rate constants were used to evaluate the treatment time required to reduce mercury content in phosphor powder to be less than 5 mg/kg. The total energy consumption in a pilot-plant-scale thermal process was evaluated to determine the optimal temperature for removing mercury in phosphor powder.

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Section: Characteristics Of Phosphor Powdermentioning

confidence: 60%

Evaluation of Energy Consumption in the Mercury Treatment of Phosphor Powder from Spent Fluorescent Lamps Using a Thermal Process

Choi

Rhee

2017

Sustainability

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“…F, C and T are weights of feed, concentrate and tailings respectively while f, c, t is their respective concentration of arsenic (As). 20,21) 2.4 Characterization and analyses X-ray diffraction (XRD) measurements for phase analysis of all solid samples were performed by using Rigaku, RINT-2200/PC system with a Cu K¡ irradiation source ( = 0.15405 nm) at 40 kV and 50 mA. Samples were analyzed in a continuous scan mode between 10 and 80°2 ª.…”

Section: Evaluation Of the Flotation Processmentioning

confidence: 99%

Investigation of Flotation Parameters for Copper Recovery from Enargite and Chalcopyrite Mixed Ore

2012

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A flotation pre-treatment study for the separation of enargite (Cu 3 AsS 4 ) from chalcopyrite (CuFeS 2 ) ores of different origins was investigated in this work. The copper ore bearing enargite mineral contained 5.87 mass% As and 16.50 mass% Cu while the chalcopyrite bearing ore contained 0.32 mass% As and 21.63 mass% Cu. The two ore samples were mixed at 7 : 3 (enargite : chalcopyrite) by weight ratio to prepare a mixed ore sample with As content at 3.16 and 18.25 mass% Cu for the flotation study. Effect of particle size, slurry pH, flotation time, collector type, collector addition or dosage and depressants were investigated to evaluate efficiency of enargite separation from chalcopyrite and recovery of both minerals as separate concentrates. For enargite single ore flotation, the 3875 µm size fraction showed that over 98% of enargite was selectively recovered within 5 min at slurry pH of 4 and As content in the final tailings was reduced to 0.22 mass%. In mix ore (enargite + chalcopyrite) flotation, 97% of enargite was first removed at pH 4 followed by chalcopyrite flotation at pH 8, and over 95% recovery was achieved in 15 min flotation time. The As content in the final tailings was reduced to 0.1 mass%.

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“…Tsuyoshi Hirajima et al [2] used collecting agents and dispersants to separate rare earth trichromatic fluorescent phosphors by flotation method. Hirajima et al [3] used diazomethane as the layered medium and sodium oleate as a surfactant to recycle rare earth fluorescent phosphors by centrifugal separation method.…”

Section: Introductionmentioning

confidence: 99%

Recycling Y and Eu from Waste Fluorescent Powder and High Temperature Solid-State Synthesis of Y2O3:Eu Phosphors

et al. 2017

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Y 2 O 3 :Eu were prepared through precursors synthesized by leaching tests, removing impurities, enrichment of Y and Eu from residual purified liquors, annealing treatment, and high temperature solid-state reaction method, which is the most suitable for large-scale production. The analysis of product shows that the purity is 99.42%. The resultant powders were characterized by X-ray diffraction (XRD), differential thermal analysis (TG-DTA), scanning electron microscope (SEM), and photoluminescence (PL). Compared with the commercial phosphors, the XRD spectrum of the product samples revealed the synthesized particles to have a pure cubic Y 2 O 3 :Eu structure without any impurities in the crystalline phase. On the morphology, the Y 2 O 3 :Eu particles synthesized by a combustion and high temperature solid state process with sintering aids, were large and uniform. For luminescence property, the emission intensity of Y 2 O 3 :Eu phosphors synthesized by combustion process and high temperature solid state process with sintering aids were higher than those without sintering aids, at 1400 • C.

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Floatability of rare earth phosphors from waste fluorescent lamps

Cited by 73 publications

References 17 publications

Evaluation of Energy Consumption in the Mercury Treatment of Phosphor Powder from Spent Fluorescent Lamps Using a Thermal Process

Evaluation of Energy Consumption in the Mercury Treatment of Phosphor Powder from Spent Fluorescent Lamps Using a Thermal Process

Investigation of Flotation Parameters for Copper Recovery from Enargite and Chalcopyrite Mixed Ore

Recycling Y and Eu from Waste Fluorescent Powder and High Temperature Solid-State Synthesis of Y2O3:Eu Phosphors

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