Separation of ultrafine ceria-based abrasive particles from glass polishing powder waste through liquid–liquid–powder extraction

Abstract

Glass polishing powder waste comprises ultrafine particles of ceria-based abrasive and polished glass powder. This study investigated the separation of ceria-based abrasive particles from glass polishing powder waste through liquid–liquid–powder extraction. Kerosene was used as the oil phase, and sodium oleate (NaOL) was used as the surfactant collector. First, the properties of the ceria-based abrasive/glass powder particles transferred from the water phase to the kerosene phase and the effect of surfactant collector addition were investigated individually. Then, separation of ceria-based abrasive from an artificial particle mixture of ceria-based abrasive and glass powder was carried out to determine the optimal extraction conditions. Finally, the method was applied to a glass polishing powder waste.The results indicated that with the addition of 2 kg/ton NaOL, more than 90% of the ceria-based abrasive particles were extracted from the water phase to the kerosene phase at a pH of 5–9. The pH and NaOL addition had negligible effect on the extracted fraction of the glass powder, which remained at approximately 10–15%. The optimal extraction conditions for the separation of ceria-based abrasive from an artificial particle mixture of ceria-based abrasive and glass powder were obtained at pH 7. Both the grade and recovery of the ceria-based abrasive in the kerosene phase solid were higher than 90% when more than 5 kg/ton NaOL was added. With the addition of 10 kg/ton NaOL, the grade was 98.5% and recovery was 97.1%. Similar results were obtained after applying this technique to a glass polishing powder waste.