• 한국자원리싸이클링학회:학술대회논문집
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• 한국자원리싸이클링학회 2006년도 춘계임시총회 및 제27회 학술발표대회
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• pp.78-85
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• 2006

In textile industries, waste effluent containing zinc is generated during the manufacture of rayon yarn from the wood pulp or cotton linters. Due to the strict environmental regulations and the presence of toxic metallic and other constituents, the discharge of industrial effluents in the sewage or disposal of solid sludge as landfill is restricted. Before recycling of zinc as zinc sulphate solution to the spinning-bath of the rayon manufacturing plant the zinc sulphate solution must be free from calcium, which is deleterious to the process as gypsum precipitates with the increase in concentration and forms scale in the bath. In the present work an attempt has been made to develop a process following solvent extraction technique using thiophosphinic extractants, Cyanex 272 and 302 modified with isodecanol and diluted in kerosene to recover zinc from rayon effluent. Various process parameters viz. extraction of zinc from different concentration of solution, distribution ratio, selective extraction, O/A ratio on extraction and stripping from the loaded organic, complex formation in the organic phase etc. have been studied to see the feasibility of the process. The extractant Cyanex 302 has been found selective for the recovery of 99.99% of zinc from the effluent above equilibrium pH 3.4 maintaining the O/A ratio of 1/30 leaving all the calcium in the raffinate. It selectively extracted zinc in the form of complex $[R_{2}Zn.3RH]_{org}$ and retained all the calcium in the aqueous raffinate. The zinc from the loaded Cyanex 302 can be stripped with 10% sulphuric acid at even O/A ratio of 10 without affecting the stripping efficiency. The stripped solution thus obtained could be recycled in the spinning bath of the rayon plant. The raffinate obtained after the recovery of zinc could be disposed safely without affacting environment.

• 공업화학
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• 제30권1호
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• pp.34-38
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• 2019

탄산화 공정을 위한 Ca 추출원으로 시멘트 산업부산물을 사용하였다. ICP와 XRD 분석을 통하여 시멘트 산업부산물은 대부분 CaO와 KCl로 구성되어 있음을 확인하였다. 최적화된 추출용제의 종류 및 농도는 1.5 M of hydrochloric acid이며 최적의 고액비는 0.1 g/mL이었다. 추출 성능 실험 결과를 통해 양이온의 추출효율은 이온 결합 형태 및 용해도에 의존함으로 판단되었다. 또한 추출 공정 후, 첨가물의 종류 및 주입 순서에 따라 선택적으로 양이온이 분리될 수 있음을 확인하였다. pH를 9.5, 13으로 조절하기 위하여 NaOH를 주입하였을 때 불순물과 $Ca(OH)_2$가 침전되었으며, $C_2H_5OH$를 주입한 경우 KCl 형태로 분리된 K가 침전되었다.