Article ID Journal Published Year Pages File Type
212112 Hydrometallurgy 2014 7 Pages PDF
Abstract

•We present a new process for the recycle of spent lithium titanate.•The parameters which affect the leaching efficiencies have been discussed.•Separation of Ti and Li from leach liquor by N1923.•Determination optimum separation conditions for Ti and Li.•Nanoscale TiO2 was obtained by a homogeneous precipitation method.

Despite the potential application of lithium titanate (Li4Ti5O12) battery, recovering Ti and Li from the spent batteries remains a largely unexplored but important topic. In this contribution, a process including leaching, extraction for the separation of titanium from leaching liquor and synthesizing TiO2 nano-particles by a homogeneous precipitation method is presented as a successful strategy. Various operating parameters were optimized, affording more than 97% leaching efficiency of both Ti and Li at a sulfuric acid solution of 4 M, H2O2 of 20 vol.%, solid-to-liquid ratio of 0.025 g mL− 1, leaching temperature of 80 °C and leaching time of 4 h. In the case of the extraction, the solvent extraction efficiency of titanium about 99% can be achieved with 30 vol.% primary amine N1923 as an extractant and kerosene as a diluent at highly acidic condition, organic phase/aqueous phase (O/A) ratio 2:1 within 10 min of contact time in ambient temperature, while the solvent extraction efficiency of lithium is only 1.4%. The raffinate was concentrated from 0.74 g L− 1 to 1.11 g L− 1 by evaporation, then lithium carbonate was precipitated by adding saturated solution of sodium carbonate affording 85% recovery. Finally, the stripping was fast with equilibrium time of 10 min with 2 M H2SO4 and titanium stripping of 98%. The results of XRD and SEM show that the size of as-prepared TiO2 powders is 100–200 nm from the stripped solution by the homogeneous precipitation method.

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Physical Sciences and Engineering Chemical Engineering Chemical Engineering (General)
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