• Title/Summary/Keyword: 배소(排簫)

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Effect of Reaction Factors on the Properties of Complex Oxide Powder Produced by Spray Roasting Process (분무배소법에 의해 생성되는 복합산화물 분말들의 특성에 미치는 반응인자들의 영향)

  • 유재근;이성수;박희범;안주삼;남용현;손진군
    • Resources Recycling
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    • v.9 no.4
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    • pp.16-27
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    • 2000
  • In order to produce raw material powder of advanced magnetic material by spray roasting process, newly modified spray roasting system was developed in this work. In this spray roasting system, raw material solution was effectively atomized and sprayed into the reaction furnace. Also, uniform temperature distribution inside reaction furnace made thermal decomposition process fully completed, and produced powder was effectively collected in cyclone and bag filter. This system equipped with apparatus which can purify hazard produced gas. In this study complex acid solution was prepared by dissolution of mill scale and ferro-Mn into the acid solution, and the pH of this complex acid solution was controlled about to 4. It was conformed that mill scale and ferro-Mn containing a lot of impurities such as $SiO_2$, P and Al could be used as raw material by reducing the impurities content of complex acid solution below 20 ppm. Complex oxide powder of Fe-Mn system was produced by spraying purified complex acid solution into the spray roaster through nozzle, and the variations of produced powder characters were studied by changing he reaction conditions such as reaction temperature, the injection velocity of solution and air, nozzle tip size and concentration of solution. The morphology of produced powder had spherical shape under the most experimental conditions, and concentration of solution. The morphology of produced powder has spherical shape under the most experimental conditions, and the composition and the particle size distribution were almost uniform, which tells the excellence of this spray roasting system. The grain size of most produced powder was below 100 nm. From the above results, it will be possible to produce ultra fine oxide powder from the chloride of Fe, Mn, Ni, Cu and rare earth by using this spray roasting system, and also to produce ultra fine pure metal powder by changing reaction atmosphere.

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A Study on Optimization of Nitric Acid Leaching and Roasting Process for Selective Lithium Leaching of Spent Batreries Cell Powder (폐 배터리 셀 분말의 선택적 리튬 침출을 위한 질산염화 공정 최적화 연구)

  • Jung, Yeon Jae;Park, Sung Cheol;Kim, Yong Hwan;Yoo, Bong Young;Lee, Man Seung;Son, Seong Ho
    • Resources Recycling
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    • v.30 no.6
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    • pp.43-52
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    • 2021
  • In this study, the optimal nitration process for selective lithium leaching from powder of a spent battery cell (LiNixCoyMnzO2, LiCoO2) was studied using Taguchi method. The nitration process is a method of selective lithium leaching that involves converting non-lithium nitric compounds into oxides via nitric acid leaching and roasting. The influence of pretreatment temperature, nitric acid concentration, amount of nitric acid, and roasting temperature were evaluated. The signal-to-noise ratio and analysis of variance of the results were determined using L16(44) orthogonal arrays. The findings indicated that the roasting temperature followed by the nitric acid concentration, pretreatment temperature, and amount of nitric acid used had the greatest impact on the lithium leaching ratio. Following detailed experiments, the optimal conditions were found to be 10 h of pretreatment at 700℃ with 2 ml/g of 10 M nitric acid leaching followed by 10 h of roasting at 275℃. Under these conditions, the overall recovery of lithium exceeded 80%. X-ray diffraction (XRD) analysis of the leaching residue in deionized water after roasting of lithium nitrate and other nitrate compounds was performed. This was done to determine the cause of rapid decrease in lithium leaching rate above a roasting temperature of 400℃. The results confirmed that lithium manganese oxide was formed from lithium nitrate and manganese nitrate at these temperatures, and that it did not leach in deionized water. XRD analysis was also used to confirm the recovery of pure LiNO3 from the solution that was leached during the nitration process. This was carried out by evaporating and concentrating the leached solution through solid-liquid separation.

Natural Language Inference using Dependency Parsing (의존 구문 분석을 활용한 자연어 추론)

  • Kim, Seul-gi;Kim, Hong-Jin;Kim, Hark-Soo
    • Annual Conference on Human and Language Technology
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    • 2021.10a
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    • pp.189-194
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    • 2021
  • 자연어 추론은 두 문장 사이의 의미 관계를 분류하는 작업이다. 본 논문에서 제안하는 의미 추론 방법은 의존 구문 분석을 사용하여 동일한 구문 정보나 기능 정보를 가진 두 개의 (피지배소, 지배소) 어절 쌍에서 하나의 어절이 겹칠 때 두 피지배소를 하나의 청크로 만들어주고 청크 기준으로 만들어진 의존 구문 분석을 사용하여 자연어 추론 작업을 수행하는 방법을 의미한다. 이러한 의미 추론 방법을 통해 만들어진 청크와 구문 구조 정보를 Biaffine Attention을 사용하여 한 문장에 대한 청크 단위의 구문 구조 정보를 반영하고 구문 구조 정보가 반영된 두 문장을 Bilinear을 통해 관계를 예측하는 시스템을 제안한다. 실험 결과 정확도 90.78%로 가장 높은 성능을 보였다.

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