Separation of gallium and arsenic from the wafer grinding extraction solution.
This work investigates the separation of gallium and arsenic from the wafer grinding extraction solution. The wafer grinding extraction solution was generated using hot and concentrated nitric acid. In this study, adsorption technology was employed to remove the toxic arsenic from the extraction solution. Ferric hydroxide was the adsorbent employed to adsorb arsenic. The effects of pH value, contact time, absorbent dosage, and chloride ion concentration on the efficiency of adsorption of gallium and arsenic were investigated. The optimal conditions for recovering gallium and removing arsenic were a raw pH of 0.2, a contact time of 6min and a ferric hydroxide concentration of 30.4g/L. Additionally, adding chloric ions reduces the residual percentage of gallium (ReGa) and the percentage of arsenic removed (RAs). Under these optimal conditions, ReGa and RAs are 100 and 80%, respectively.
Department of Center for Environmental Safety and Health Technology, Industrial Technology Research Institute, Chutung, Hsinchu, Taiwan. Y_FChen@itri.org.tw
Yi-Fu
YF
Chen
Fong-Ru
FR
Yang
Jeng-Shyong
JS
Jean
Chin-Ying
CY
Tsai
D000327:Adsorption; D001151:Arsenic / Q000302:isolation & purification*; D005290:Ferric Compounds / Q000737:chemistry; D005708:Gallium / Q000302:isolation & purification*; D006256:Hazardous Waste; D006863:Hydrogen-Ion Concentration; D008420:Manufactured Materials; D012037:Refuse Disposal; D012666:Semiconductors; D014873:Water Pollutants / Q000302:isolation & purification*
D005290:Ferric Compounds; D006256:Hazardous Waste; D014873:Water Pollutants; C021024:ferric hydroxide; D005708:Gallium; D001151:Arsenic