• Resources Recycling
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• v.30 no.1
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• pp.44-52
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• 2021

This study investigated the effect of the type of alkaline precipitant used on the synthesis of lithium hydroxide by examining the behavior of lithium hydroxide produced using lithium sulfate recovered from a waste lithium secondary battery as a raw material. The double-replacement reaction (DRR) process was used to remove the impurities contained in the lithium salt precursor of lithium sulfate and to improve the efficiency of the synthesis of lithium hydroxide. The experiment was conducted by control the molar ratio of the precursor ([Li]/[OH]), the reaction temperature, and the composition of the alkaline precipitant (KOH, Ca(OH)2, Ba(OH)2) used for the production of highly-crystalline lithium hydroxide. A secondary solid-liquid separation was performed following the reaction to remove the impurities generated, and the purified aqueous solution of lithium hydroxide was evaporated to remove the moisture and obtain the product as a powder. The crystallinity and synthesis behavior of the product were examined.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.31 no.2
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• pp.89-95
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• 2021

Research on the production of lithium hydroxide (LiOH) has been actively conducted in response to the increasing demand for high nickel-based positive electrode materials for lithium-ion batteries. Herein we studied the conversion of lithium oxide (Li2O) through thermal decomposition of lithium carbonate for the production of lithium hydroxide from lithium carbonate (Li2CO3). The reaction mechanism of lithium carbonate with alumina, quartz and graphite crucible during heat treatment was confirmed. When graphite crucible was used, complete lithium oxide powder was obtained. Based on the TG analysis results, reagent-grade lithium carbonate was heat-treated at 700℃, 900℃ and 1100℃ for various time and atmosphere conditions. XRD analysis showed the produced lithium oxide showed high crystallinity at 1100℃ for 1 hour in a nitrogen atmosphere. In addition, several reagent-grade lithium oxides were reacted at 100℃ to convert to lithium hydroxide. XRD analysis confirmed that lithium hydroxide (LiOH) and lithium hydroxide monohydrate (LiOH·H2O) were produced.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.29 no.5
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• pp.222-228
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• 2019

In this study, we carried out the experiment to prepare lithium carbonate powder through gas-liquid reactions with a lithium-containing solution and $CO_2$ gas using lithium hydroxide, lithium chloride, and lithium sulfate. Thermodynamically, the carbonation reaction of a lithium-containing solution showed that aqueous reaction of lithium hydroxide occurs spontaneously, but aqueous reactions of lithium chloride and lithium sulfate does not occur spontaneously. In the case of lithium hydroxide solution, the recovery rate of lithium carbonate was 69.8 % at room temperature ($25^{\circ}C$), and increased to 89.4 % at $60^{\circ}C$. In the case of lithium chloride and lithium sulfate solution, lithium carbonate could be prepared using sodium hydroxide as an additive, but the recovery rates were 19.2 % and 16.7 %, respectively.

• Resources Recycling
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• v.28 no.5
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• pp.60-67
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• 2019

A valuable metal recovery from waste resources such as spent rechargeable secondary batteries is of critical issues because of a sharp increase in the amount of waste resources. In this context, it is necessary to research not only recycling waste lithium-ion batteries (LIBs), but also reusing valuable metals (e.g., Li, Co, Ni, Mn etc.) recovered from waste LIBs. In particular, the lithium hydroxide ($LiOH{\cdot}xH_2O$), which is of precursors that can be prepared by the recovery of Li in waste LIBs, can be reused as a catalyst, a carbon dioxide absorbent, and again as a precursor for cathode materials of LIB. However, most studies of recycling the waste LIBs have been focused on the preparation of lithium carbonate with a recovery of Li. Herein, we show the preparation of high purity lithium hydroxide powder along with the precipitation process, and the systematic study to find an optimum condition is also carried out. The lithium carbonate, which is recovered from waste LIBs, was used as starting materials for synthesis of lithium hydroxide. The optimum precipitation conditions for the preparation of LiOH were found as follows: based on stirring, reaction temperature $90^{\circ}C$, reaction time 3 hr, precursor ratio 1:1. To synthesize uniform and high purity lithium hydroxide, 2-step precipitation process was additionally performed, and consequently, high purity $LiOH{\cdot}xH_2O$ powder was obtained.

• Resources Recycling
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• v.33 no.1
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• pp.15-21
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• 2024

The demand for electric vehicles powered by lithium-ion batteries is continuously increasing. Recovery of valuable metals from waste lithium-ion batteries will be necessary in the future. This research investigated the effect of reaction temperature on the lithium recovery ratio from hydrogen reduction followed by water leaching from lithium-ion battery NCM-based cathode materials. As the reaction temperature increased, the weight loss ratio observed after initiation increased rapidly owing to hydrogen reduction of NiO and CoO; at the same time, the H₂O amount generated increased. Above 602 ℃, the anode materials Ni and Co were reduced and existed in the metallic phases. As the hydrogen reduction temperature was increased, the Li recovery ratio also increased; at 704 ℃ and above, the Li recovery ratio reached a maximum of approximately 92%. Therefore, it is expected that Li can be selectively recovered by hydrogen reduction as a waste lithium-ion battery pretreatment, and the residue can be reprocessed to efficiently separate and recover valuable metals.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.30 no.2
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• pp.55-60
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• 2020

In the previous study, we reported the result to prepare lithium carbonate powder from various lithium-contained solution. Therefore, using the lithium hydroxide solution, it is conformed that the reaction could occur thermodynamically, and the recovery rate of lithium was 89.4 %. In this study, we carried out the experiment to prepare lithium carbonate powder through gas-liquid reactions with lithium hydroxide solution and CO₂ gas using ultrasound energy. In case ultrasonic energy is applied to the reaction of lithium carbonate, the recovery rate of lithium at room temperature was approximately 83.8 %, and the recovery rate of lithium was greatly increased to approximately 99.9 % at 60℃ reaction temperature. And when ultrasonic energy is not applied, the particle size of lithium carbonate powder was 7.7 ㎛ in D50. But the particle size of lithium carbonate powder was significantly reduced to 8.4 ㎛ in D50 under the influence of ultrasonic.

• Proceedings of the Korean Nuclear Society Conference
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• 1997.05b
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• pp.86-91
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• 1997

지르칼로이는 피복관으로 우수한 성질을 갖고있으나 고온에서 수증기와 발열반응을 일으켜 원자로의 안전성을 떨어뜨리는 단점을 가지고 있다. 사고시 1차 계통수에 함유된 수산화 리튬이니 붕소산은 지르칼로이에 흡착되어 산화에 영향을 줄 수 있다. 본 연구에서는 고온 수증기중의 지르칼로이 산화의 정확한 기술에 대한 연구를 수행하였으며 흡착물의 영향에 대한 실험을 수행하였다. 지르코늄 산화막이 단사정으로 존재하는 온도구간($650^{\circ}C$-105$0^{\circ}C$)에서 지르칼로이의 기존의 자료를 기반으로 계산 모형을 설정하였고 계산결과 Baker-just의 실험식은 상당히 보수적임을 알 수 있었다. 수산화리튬이 흡착된 시편은 1기압 고온 수증기중에서 산화시 푸른 간섭무늬의 막이 생성되어 산화가 억제되었다. 붕소산과 리튬의 혼합용액을 흡착한 시편은 푸른 간섭무늬의 막이 생성되지 않았으며 아무것도 흡착하지 않은 시편과 산화속도가 거의 같았다 고온 산화에서 열충격은 산화막의 균열을 발생하게 하여 산화가 가속되게 하고 지르칼로이의 기억효과를 상실케 한다.

• Resources Recycling
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• v.23 no.3
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• pp.21-29
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• 2014

This study was conducted to obtain the basic data for designing the lithium recovery process from the "salar de Uyuni" in Bolivia. For this study, the mock brine which has the similar chemical composition with the brine of "salar de Uyuni" was prepared, and the effects of reaction factors such as temperature, time, pH and so forth on the precitation reaction of magnesium hydroxide were investigated.

• Membrane Journal
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• v.32 no.6
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• pp.401-410
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• 2022

Demand for lithium hydroxide (LiOH) is annually increasing due to its efficiency and safety for the environment in comparison to its current alternatives. Lithium can be found in different salty and brine lakes which later synthesized to produce LiOH for various applications. Different methods are used to separate and recover lithium ions, the most common of which is electrodialysis (ED). ED is a membrane-based separation technique which works on potential difference of its layers as a driving force to push ions from one side to another. The ion exchange membrane (IEM) in ED makes the process efficient because of the perm selectivity of different ions vary depending on their hydrodynamic volume. In this review, the different alteration strategies of both ED and IEM, to enhance the recovery of lithium ions are discussed.

• Nuclear Engineering and Technology
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• v.27 no.4
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• pp.591-602
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• 1995

가압경수로에서는 장기적인 반응도 조절을 위하여 B-10과 B-11을 함유한 천연붕산을 사용한다. 천연붕산의 사용으로 원자로냉각재의 붕소농도가 높기 때문에 pH를 적정한 범위로 유지하기 위하여 많은 양의 수산화리튬이 주입된다. 이로 인한 높은 리튬 농도는 증기발생기 재질의 응력부식균열과 핵연료피복재의 산화를 촉진시키는 등의 부작용을 초래할 수 있다고 보고되었다. 따라서 본 고에서는 천연붕산을 B-10 함량이 높은 농축붕산으로 대체하는 경우에 대한 기술적, 경제적 영향을 조사하고 검토하였다. 조사 결과, 농축붕산은 원전의 일차계통 수질화학, 부식생성물의 방사화에 의한 선량율, 보조계통 설계, 액체폐기물 발생량관점에서 여러가지 이점이 있을 수 있으며, 노심설계, 안전해석, 발전소 인허가 등의 관점에서는 문제가 없다고 밝혀졌다. 현재 천연붕산으로 운전중인 원전에서는 농축붕산의 경제성이 발전소의 주어진 제반여건에 의존하고, 농축붕산의 가격에 따라 크게 차이가 있는 것으로 보고되었다. 국내에 신규 원전이 계속적으로 건설되고 있는 현실에 비추어 볼 때, 발전소의 경제성과 안전성을 향상시키기 위하여 농축붕산 사용에 대한 타당성을 좀 더 면밀히 분석 할 필요가 있다고 판단된다.