| Gallium is a relatively rare element and its principal use in the manufacture of semiconducting compounds, mainly GaAs. Consequently, a large increase in the demand for gallium is anticipated in the future. Recycling of GaAs wafer scrap is required to solve the environmental problems caused by arsenic and to reutilize gallium which is an expensive metal. To recovery of gallium from the GaAs scrap, the basic study on the gallium leaching was performed with varying leaching agents and conditions. The important results were obtained such as followings; Nitric acid was the most effective leaching agent in comparison with HCl and H₂SO₄. More than 99% of Gallium was leached at conditions; 2N HNO₃, 500RPM, -100+200 mesh and at 60℃. The apparent activation energy of the leachuig reaction was 93.05 KJ/mole. The total reaction rate of this reaction was as follow : [dGa(III)/dt]_i=k′[GaAs]^(2.32)·[HNO₃]^(3.20)·Exp(-93.05/RT) |
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