Two-step liquid-liquid extraction methods using aqueous and organic phases for separation of red (Y2O3: Eu 3+), blue (BaMgAl10O17: Eu 2+) and green (CeMgAl10O17: Tb 3+) fine fluorescent powders were proposed in this paper. At first, the blue powder was extracted selectively into heptane phase using a chelating agent, 2-thenoyltrifluoroacetone (HTTA, CF3COCH2COC4H3S) under alkaline pH condition. Then, chloroform was used for extracting the green powder into the chloroform phase. The red powder separating from the green powder remained in aqueous phase with a depressant, potassium sodium tartrate tetrahydrate (PST, KNaC4H4O6•4H2O). The powders could be well separated in terms of their grade and recovery. The results suggested directions for future research into the recycling of fluorescent powders from fluorescent lights.

Lithium cobalt oxide from a wasted lithium ion secondary battery (LIB) is recovered by means of flotation. At first, the wasted LIB was crushed by vertical cutting mill and classified by air table and vibration screen. Referring to the crushing and separating results, wasted LIB is represented by light materials (organic separator of anode and cathode of battery), metallic materials (aluminum & copper foil, aluminum case etc.) and electrode materials (mixture of lithium cobalt oxide (LiCoO2) and graphite). Electrode materials were thermally treated in a muffle furnace at 773K, followed by flotation to separate LiCoO2 and graphite. The fact that the surface of particles was changed from hydrophobic to hydrophilic due to the removal of binder from the surface at 773K. Considering the results, 92% LiCoO2 was recovered from electrode materials, whereas the purity was higher than 93%. The optimum conditions of flotation process were as follows: 0.2 kg/t kerosene as a collector, 0.14 kg/t MIBC as a frother and 10% pulp density. The experimental results suggested that this process by using mineral processing technology, such as crushing, screening, flotation, etc., is feasible to recover LiCoO2 from the wasted LIB representing a new recycling technique.

Separation of Red (Y 2 O 3 : Eu 3+ ), Blue (Sr, Ca, Ba) 10 (PO 4 ) 6 Cl 2 : Eu 2+ and Green (LaPO 4 : Tb 3+ , Ce 3+ ) Rare Earth Phosphors by Liquid/Liquid Extraction Abstract: A novel process for separation of red (Y 2 O 3 : Eu 3＋ ), blue (Sr, Ca, Ba) 10 (PO 4 ) 6 Cl 2 : Eu 2+ and green (LaPO 4 : Tb 3＋ , Ce 3＋ ) fine tricolor phosphor powders was established. First, the green phosphor was extracted and separated from three phosphor mixtures in heptane/DMF(N, N-Dimethylformamide) system using stearylamine or laurylamine (DDA) as the cationic surfactant. Then, after being treated with 99.5% ethanol, the blue and red phosphors could be separated in Heptane/DMF system in presence of 1-octanesulfonic acid sodium salt as the anionic surfactant. Satisfactory separation results have been achieved through two steps extractions with their artificial mixtures. The grades and recovery of separated products reached respectively as follows: red product was 95.3% and 90.9%, blue product was 90.0% and 95.2%, and green product was 92.2% and 91.8%.

A novel process for separation of red (Y 2 O 3 :Eu 3+ ), blue(BaMgAl 10 O 17 :Eu 2+ ) and green (CeMgAl 10 O 17 :Tb 3 ) rare earth fluorescent powders was proposed. At first, the blue powder can be extracted selectively from an aqueous solution using a chelating collector 2-thenoyltrifluoroacetone (TTA) dissolved in heptane at alkaline pH condition, then, chloroform was used for extracting the green powder into organic phase. The red phosphor remains in aqueous phase with potassium sodium tartrate depressant (PST). Therefore, three phosphors can be separated successfully from their artificial mixtures by liquid/liquid extraction, and grades and recovery of separated products reach respectively as follows: red is 96.9% and 95.2%, blue is 82.7% and 98.8%, green is 94.6% and 82.6%.

We have found that a Raman scattering (RS) peak around 1870 cm−1 was produced by the annealing of the X-ray irradiated film of single-walled carbon nanotubes (SWNTs) at 450 oC. The intensity of 1870-cm−1 peak showed a maximum at the probe energy of 2.3 eV for the RS spectroscopy with various probe lasers. Both the peak position and the probe-energy dependence were almost identical to those of the one-dimensional carbon chains previously reported in multi-walled carbon nanotubes. Consequently, we concluded that the 1870-cm−1 peak found in the present study is attributed to carbon chains. The formation of carbon chains by the annealing at temperature lower than 500 oC is firstly reported by the present study. The carbon chains would be formed by aggregation of the interstitial carbons, which are formed as a counterpart of carbon vacancies by X-ray irradiation diffused on SWNT walls. The result indicates that the combination of X-ray irradiation and subsequent thermal annealing is a feasible tool for generating new nanostructures in SWNT.