Recycling of Silicon Powder Retrieved from Diamond Wire Slicing Kerf

Abstract

Recycling procedure to retrieve the Silicon from the diamond wire saw sludge is proposed and examined. In order to clarify the impact of common impurities in the silicon sludge. The resulting evolution curves from the TDPMS measurement indicate that most of the organic gases will have high evolution intensity at temperatures below 200°C. However, CO and N2 have almost the same evolution all over the range of temperatures between 100 and 1000°C. Model experiment was performed to investigate the impact of nickel and carbon on multicrystalline ingot quality. The diffusion length distribution was normal in the nickel contaminated ingot and comparable non-contaminated ingots while the carbon contaminated ingot have poor quality if compared with non-contaminated ingots. The Total oxygen measurement was used to evaluate the oxygen contents in our swarf material and the total oxygen contents were found to be below 5 %. We succeeded to melt the silicon swarf in small scale experiment and the impurity concentration was compared to the initial impurity concentrations in the silicon swarf.