사파이어 커프 폐기물 재활용: 연구

최근 몇 년 동안，과학 기술의 진화，사파이어 웨이퍼는 LED와 전자 산업에서 beenwidely 적용되고 웨이퍼의 사파이어 wafer.The 간격으로 저미어질 때까지 LED 분야에 직접 적용될 수 없는 전자 industry.Sapphire 주괴는 대략 0.2mm입니다，다이아몬드 와이어의 직경에 가까움，which means about 40％～50％sapphire ingot materials are transformed into powder washed away by the cooling liquid．

LED industry develops rapidly，이는 점점 더 많은 사파이어 웨이퍼가 결과 demanded.As 있음을 의미합니다，more and more sapphire diamond-sawing cutting waste will be produced，sapphire diamond-wire cutting waste was mostly disposed with accumulation or landfill，which reasonably made no use of the resources and causes great pollution to the environment．Hence，removing impurity from the cutting waste and recycling the Q-A1203 to reproduce sapphire single crystal are urgently required，which will make remarkable economic and environmental benefits．The purpose of this investigation is to explore a way to recycle and purify the for reproducing sapphire single crystal．The diamond-sawing waste was used as raw material which is provided by，Ltd in this paper，the results of the research are as follows：

우선，the analysis of the cutting waste after washing，drying and sieving shown that the main component of the cutting waste is alpha alumina with nickel and diamond as main impurities，where the contents of impurity nickel and diamond were 0．70％and 0．1 64％，respectively．Then，the efficient conditions of conventional acid leaching and ultrasound acid leaching of nickel were determined．Under these conditions，the content of nickel reduced

from 0．70％to 0．0 1 2％and 0．009％with 98．25％and 99．67％leaching ratio，respectively．As can be seen that ultrasound acid leaching is beRer than conventional acid leaching．Kinetic analysis of ultrasound acid leaching and conventional acid leaching shown that the process of Ni reacting with acid is controlled by chemical reaction．By determining the optimum conditions of extraction and baci-extraction，the recovered solution was evaporated and crystallized to obtain nickel sulfate crystals with a recovery rate of 95．32％．

둘째，이 diamond—sawing curing waste was put into furnace reacting with oxygen after leaching．Under the optimized burning conditions，the contents of diamond in cutting waste were reduced to 0．00062％from 0．1 64％，the removal rate of diamond was 99．62％．Kinetic analysis of burning process shown that the reaction，diamond burning in the oxygen，fits reaction—controlled shrinking core model．After being purified，the purity of 0-A1203 in diamond—sawing cutting waste is 99．99％，which basically meet the demand for reproducing sapphire ingot．

자주 묻는 질문

Why should sapphire cutting waste be recycled?

Because sapphire wafers (~0.2 mm) are nearly as thin as the diamond wire itself, 40-50% of each expensive ingot turns into waste powder during slicing. This waste was mostly dumped or landfilled, wasting a valuable resource and polluting the environment, so recovering the alpha-alumina for new crystal growth brings major economic and environmental benefits.

What impurities are in sapphire diamond-wire cutting waste?

After washing, drying and sieving, the waste is mainly alpha-alumina with two key impurities: nickel at 0.70% and diamond at 0.164%, both introduced by the wire sawing process itself.

How is nickel removed from sapphire cutting waste?

By acid leaching, and ultrasound-assisted leaching outperforms the conventional method: nickel content drops from 0.70% 받는 사람 0.009% a 99.67% 침출 비율, versus 0.012% 그리고 98.25% for conventional leaching. The recovered solution yields nickel sulfate crystals at a 95.32% recovery rate through extraction, back-extraction, evaporation and crystallization.

Can purified sapphire cutting waste be reused to grow new sapphire?

예. After leaching removes the nickel and optimized oxygen burning removes the diamond (down to 0.00062%, a 99.62% removal rate), the alpha-Al2O3 purity reaches 99.99% — basically meeting the purity demand for reproducing sapphire single crystal ingots.

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