Production of zinc and manganese oxide particles by pyrolysis of alkaline and Zn–C battery waste

Production of zinc and manganese oxide particles from alkaline and zinc–carbon battery black mass was studied by a pyrolysis process at 850–950 °C with various residence times under 1 L/min N2(g) flow rate conditions without using any additive. The particular and chemical properties of the battery waste were characterized to investigate the possible reactions and effects on the properties of the reaction products. The thermodynamics of the pyrolysis process were studied using the HSC Chemistry 5.11 software. The carbothermic reduction reaction of battery black mass takes place and makes it possible to produce fine zinc particles by a rapid condensation, after the evaporation of zinc from a pyrolysis batch. The amount of zinc that can be separated from the black mass is increased by both pyrolysis temperature and residence time. Zinc recovery of 97% was achieved at 950 °C and 1 h residence time using the proposed alkaline battery recycling process. The pyrolysis residue is mainly MnO powder with a low amount of zinc, iron and potassium impurities and has an average particle size of 2.9 μm. The obtained zinc particles have an average particle size of about 860 nm and consist of hexagonal crystals around 110 nm in size. The morphology of the zinc particles changes from a hexagonal shape to s spherical morphology by elevating the pyrolysis temperature

Effects of gas flow rate on zinc recovery rate and particle properties by pyrolysis of alkaline and zinc-carbon battery waste

Zinc (Zn) recovery rate and the properties of Zn particles obtained by pyrolysis of alkaline and Zn-C battery waste were studied at a reaction temperature of 950 degrees C for 60 min residence time using various N-2(g) flow rate (0.5-3.014min) without using any additive. The battery black mass was characterized with respect to the properties of waste battery particles, and chemical content. The thermodynamics of the pyrolysis process was studied using the HSC Chemistry 5.11 software. A carbothermic reduction reaction of the washed battery black mass by Milli-Q water takes place at choosen temperature and makes it possible to produce fine Zn particles by a rapid condensation following the evaporation of zinc from the pyrolysis batch. The amount of Zn that can be separated from the black mass slightly increases at higher N-2(g) flow rates than 0.5 L/min and stabilizes by controlling the gas flow. Zn recovery of 80% was achieved at 950 degrees C and 60 min residence time using 1.0 L/min and higher flow rates by pyrolysis of the washed battery black mass. The pyrolysis residue was shown to be mainly composes of MnO and Mn2O3 with traces of impurities. The particle size of the produced Zn particle decreased from 874nm to 534 nm with increasing flow rate and those particles are formed by the aggregation of primary condensed particles with nano-range sizes. The morphology of the zinc particles also changes from hexagonal shape to spherical morphology by increasing gas flow rate

Disassembly of old radium sources and conversion of radium sulfate into radium carbonate for subsequent dissolution in acid

In this work details of safe radium source disassembly which were previously used in brachytherapy are described and different methods for conversion of RaSO4 into aqueous solution are reviewed. The method of choice included three cycles of RaSO4 heating in 1.5 M Na2CO3 up to 85 °C, cooling and subsequent removal of supernatant. X-ray diffraction study showed that the method allows the synthesis of, presumably, amorphous RaCO3, which can be dissolved in mineral acid. Gamma spectrometric measurements showed that most of the initial RaSO4 was converted into solution and that 7 ± 1 % of the initial 210Pb was co-precipitated with RaCO3

Single-Step Production of Nanostructured Copper-Nickel (CuNi) and Copper-Nickel-Indium (CuNiIn) Alloy Particles

Nanostructured copper-nickel (CuNi) and copper-nickel-indium (CuNiIn) alloy particles were produced from aqueous solutions of copper, nickel nitrates and indium sulfate by hydrogen reduction-assisted ultrasonic spray pyrolysis. The effects of reduction temperatures, at 973 K, 1073 K, and 1173 K (700 A degrees C, 800 A degrees C, and 900 A degrees C), on the morphology and crystalline structure of the alloy particles were investigated under the conditions of 0.1 M total precursor concentration and 0.5 L/min H-2 volumetric flow rate. X-ray diffraction studies were performed to investigate the crystalline structure. Particle size and morphology were investigated by scanning electron microscope and energy-dispersive spectroscopy was applied to determine the chemical composition of the particles. Spherical nanocrystalline binary CuNi alloy particles were prepared in the particle size range from 74 to 455 nm, while ternary CuNiIn alloy particles were obtained in the particle size range from 80 to 570 nm at different precursor solution concentrations and reduction temperatures. Theoretical and experimental chemical compositions of all the particles are nearly the same. Results reveal that the precursor solution and reduction temperature strongly influence the particle size of the produced alloy particles