• Journal of the Korean Electrochemical Society
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• v.4 no.2
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• pp.77-81
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• 2001

Recently, used batteries are causing an environmental contamination and a waste of limited resources with increasing demand of portable secondary batteries in market. In developed countries, their governments have legally required the manufacture to collect and recycle the used batteries, so the related companies have formed an organization for collecting the used batteries and they are effectively recycling them. Unfortunately, an infrastructure for collecting and recycling the used batteries are not established at home yet, while volume of the used batteries are increasing. Therefore, we need an effective measure to ensure the recycling of the used batteries as soon as possible.

• Clean Technology
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• v.27 no.2
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• pp.139-145
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• 2021

The purpose of this study is to recover valuable metals from spent batteries using a dry process. We focused on the effect of the smelting temperature on the composition of recovered solid and liquid products and collected gaseous products. After removal of the cover, the spent battery was left in NaCl solution and discharged. Then, the spent battery was made into a powder form through a crushing process. The smelting of the spent battery was performed in a tubular electric furnace in an oxygen atmosphere. For spent lithium-ion batteries, the recovery yield of the solid product was 80.1 wt% at a reaction temperature of 850 ℃, and the final product had 27.2 wt% of cobalt as well as other metals such as lithium, copper, and aluminum. Spent nickel-hydrogen batteries had a recovery yield of 99.2 wt% at a reaction temperature of 850 ℃ with about 37.6 wt% of nickel and other metals including iron. For spent nickel-cadmium batteries, the yield decreased to 65.4 wt% because of evaporation with increasing temperature. At 1050 ℃, the recovered metals were nickel (41 wt%) and cadmium (12.9 wt%). Benzene and toluene, which were not detected with the other secondary waste batteries, were detected in the gaseous product. The results of this study can be used as basic data for future research on the dry recycling process of spent secondary batteries.

• Proceedings of the Korean Vacuum Society Conference
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• 2010.02a
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• pp.293-293
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• 2010

최근 태양전지 연구에서 저가격화를 실현하는 방법 중 하나로 폐 실리콘 웨이퍼를 재생하는 방법에 관하여 많은 연구가 진행되고 있다. 그러나 기존 웨이퍼 재생공정은 높은 재처리 비용과 복잡한 공정등의 많은 단점을 가지고 있다. 챔버 내에 압축된 공기나 가스에 의해 가속된 미세 파우더들이 재료와 충돌하면서 식각하는 기계적 건식 식각 공정 기술이라고 할 수 있는 micro blaster 공정을 이용하면 기존 재생공정보다 낮은 재처리 비용과 간단한 공정으로 재생웨이퍼를 제작할 수 있다. 하지만 이러한 micro blaster 공정은 식각 후 표면에 많은 particle과 crack을 형성시켜 태양전지용으로 사용하기에 단점을 가진다. 본 연구에서는 이러한 micro blaster를 이용한 태양전지용 재생 웨이퍼를 제작하기 위해 폐 실리콘 웨이퍼의 표면 물질을 식각하고, 식각 후 충돌에 의해 발생된 표면의 particle과 crack을 DRE(Damage Remove Etching)공정으로 제거하는 연구를 진행 하였다. 먼저 폐 실리콘 웨이퍼와 같은 표면을 형성하기 위하여 시편 표면에 각각 Al($2000{\AA}$), $Si_3N_4(3000{\AA})$, $SiO_2(1{\mu}m)$, AZ1512($1{\mu}m$)을 형성하고 micro blaster의 파우더 크기, 압력, 스캔 속도 등의 공정 조건에 따라 폐 실리콘 웨이퍼 표면 물질을 식각하였다. 식각 후 폐 실리콘 웨이퍼의 식각된 깊이와 표면 물질 잔량을 측정하고, 폐 실리콘 웨이퍼의 표면에 particle과 crack, 요철이 형성되어 있는지를 확인하였다. 그 결과 폐 실리콘 웨이퍼에 형성된 물질의 두께 이상으로 식각되었으며, 표면 물질의 잔량이 남아 있지 않았고, 표면에 많은 particle과 crack, 요철이 형성되었다. 표면에 형성된 요철은 유지하면서 많은 particle과 crack을 제거하기 위하여 micro blaster공정 후 DRE 공정으로 표면 개선이 필요하였다. 이때 남겨진 요철은 입사광량을 증가시키고, 표면 반사율을 감소시켜 태양전지내의 흡수하는 빛의 양을 증가시키는 태양전지 texturing 공정 효과로 작용하게 된다. 표면에 남은 particle과 crack을 완전히 제거하면서 요철은 유지할 수 있게 HNA 용액의 농도와 시간에 따른 식각 정도를 측정하였다. DRE 공정 후 표면 particle과 crack이 완전히 제거되어 표면이 개선됨을 확인하였다. Micro blaster를 이용하여 폐 실리콘 웨이퍼의 표면을 식각하고, DRE공정으로 표면을 개선함으로써 태양전지용 기판으로의 재생 가능성을 확인하였다.

• Resources Recycling
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• v.10 no.3
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• pp.43-50
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• 2001

Characteristics of crushing and magnetic separation on the spent batteries, were investigated for reclaiming spent carbon-zinc and alkaline manganese dioxide batteries. Crushing of carbon zinc battery was easier than that of alkaline $MnO_2$battery using impact type crusher with rotary blades. Most of magnetic products were distributed in the range of 8 mesh size. With crushing 1 ton of spent carbon-zinc and alkaline $MnO_2$batteries respectively, magnetic separation of 8 mesh oversize particles, we can get 214 kg and 235 kg of magnetic products which is composed of 94% and 88% of Fe.

• Resources Recycling
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• v.9 no.6
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• pp.3-8
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• 2000

A reaction between the depolarizing mixture in the spent manganese batteries and ($NH_4$)$_2$$SO_4$was carried out to find a new process for the extraction of Mn component from the spent manganese batteries. The optimum conditions were as follows : the reaction temperature $425^{\circ}C$, ($NH_4$)$_2$$SO_4$weight ratio to the depolarizing mixture in the spent manganese batteries 12.0, reaction time 60 min. Under above conditions manganese was extracted 93.5%.

• Resources Recycling
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• v.4 no.1
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• pp.46-51
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• 1995

After removal of mercury in the silver oxide batteries with the distillation process, the leaching of valuable metals from the residue was studied. The distilled residue was reacted with the various HNO, concentration, reactlon temperature, readion time and pulp density. It was found that the optimum condition for leachmg was 2N HNO,, 40-60% reaction temperature, 6 hours reaction tlme and 10g/200ml pulp density. More than 99% of silver and zinc were dissolved in this process while less than 50% of iron and nickel were leached

• 월간산업보건
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• no.9 s.245
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• pp.44-55
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• 2008

• Resources Recycling
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• v.16 no.6
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• pp.10-19
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• 2007

The mechanical process followed by hydrometallurgical treatment has been developed in order to recover cobalt and lithium from spent lithium ion battery. In the previous study, a citrate precursor combustion process to prepare cathodic active materials from the leaching solution was elucidated. Resynthesis of electrode materials should be more valuable in spent battery recycling. Conventional slurry mixing of $LiCoO_2$ and carbon cannot make uniform distribution, and therefore the cathode cannot reach the theoretical charge-discharge capacity and is easily degraded during the charge-discharge cycling. In this study, ultra-fine $LiCoO_2$ powders has been prepared by modification of the combustion process and fabricated the enhanced cathode by modification of mixing method of $LiCoO_2$ and carbon added.

• Resources Recycling
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• v.14 no.4 s.66
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• pp.17-21
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• 2005

Deep-sea Manganese nodules was treated with reduction-smelting process with adding the spent Ni-Cd battery or the cobalt contained spent catalyst for recovery of nickel and cobalt metals. The nickel in the spent Ni-Cd battery could be recovered by adding $5\%$ coke as a reducing agent regardless of the amount of battery added. However, to recover cobalt from the spent catalyst, it is require to add more coke for reduction of cobalt oxide in the catalyst. The treatment of metal wastes with manganese nodules can contribute to lower the cost for the processing of nodules and to facilitate the recycling of metal wastes.

• Resources Recycling
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• v.16 no.4
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• pp.3-9
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• 2007

Dismantlement of lithium primary batteries without explosion is required to recycle the lithium primary batteries which could be exploded by heating too much or crushing. In the present study, the optimum discharging condition was investigated to dismantle the batteries without explosion. When the batteries were discharged with $0.5kmol{\cdot}m^{-3}$ sulfuric acid, the batteries became inert after 4 days at $35^{\circ}C$ and after 1 day at $50^{\circ}C$, respectively. This result shows that higher temperature accelerates inert of the batteries. Because loss of metals recycled increases when the batteries are discharged only with the sulfuric acid, discharging process using acid solution and water was newly proposed. When the batteries were discharged with water during 24 hours after discharging with $0.5kmol{\cdot}m^{-3}$ sulfuric acid during 6 hours, the batteries discharged were dismantled without explosion. Because decrease in loss of metals was accomplished by new process, the recycling process of the batteries could become economic by the 2-step discharging process.