국내 자원의 절약과 재활용 촉진에 관한 법률에 근거한 생산자책임재활용제도(EPR System)의 대상 품목인 폐형광등은 2017년 기준 재활용 의무율은 35.6%로 책정되었으며 한국환경공단에 따르면 2015년 기준 형광등의 출고량은 약 18 천톤 정도로 나타났으나 공제조합과 재활용업 간의 재활용 위・탁 계약의 미체결로 인해 폐형광등의 실제 재활용율은 약 5.0%로 재활용 의무율을 달성하지 못하고 있는 실정이다(「생산자책임재활용제도 시행 13년」 운영성평가, 한국환경공단, 2017). 폐기물로 발생되는 폐형광등에 관한 선행연구에 따르면 폐형광등에 포함된 수은은 대부분 형광분말에 포함되어 있어 이를 적절하게 처리할 필요가 있다. 또한, 형광분말에는 희유금속(이트륨, 유로퓸 등)이 포함되어 있어 형광분말에 포함된 수은을 제거하여 희유금속을 회수하여 희유금속을 필요로 하는 산업체 등에서 활용할 수 있다. 이를 위하여 폐형광등 형광분말에 포함된 수은을 제거하기 위하여 Pilot plant 규모의 폐형광등 형광분말 증류 실험을 실시하였다. 실험의 원료는 경기도 K대학에 설치된 Pilot plant 규모의 폐형광등 재활용 공정에서 회수되는 폐형광등 형광분말을 사용하였다. Pilot plant 규모의 폐형광등 형광분말의 수은증류 실험의 조건으로 증류온도는 400~600℃로 변화시켰고 각 온도에서 증류장치 내 체류시간을 1~8시간으로 변화시켰다. 본 연구에서는 각 실험조건에서 회수되는 형광분말의 수은함량을 분석하였고 증류온도와 체류시간에 따른 수은함량을 비교하여 반응속도를 고찰하였다. 또한, 각 실험조건에서 소모되는 에너지양을 비교하여 Pilot plant 규모의 폐형광등 형광분말 증류장치의 최적 에너지 사용량을 평가하고자 하였다.
Material flow analysis (MFA) of recycling material and of mercury from linear-type spent fluorescent lamps (SFLs was performed to estimate the material composition of the chain recycling process by an input-output approach. The recycling process system for linear-type SFLs was established using an end-cutting system, a hammer crusher, a screen separation system, a mercury distillation system, and an activated carbon adsorption component. From the results of the MFA of lineartype SFLs, 92% of materials used in linear-type SFLs such as glass, aluminum, and phosphor powder can be recycled. For MFA of mercury, the mercury content in the phosphor powder was the highest among material compositions tested and the total mercury amount in the recycling materials from 1 ton of SFLs was estimated to be 75.43 g. In the recycling process system for linear-type SFLs, the mercury amount in the vapor phase was analyzed and found to be 2228 mg in the endcutting system, 172 mg in the hammer crusher, and 2585 mg in the screen separation system. The total mercury amount in the vapor phase was estimated to be 4985 mg, which was only 6.22% of the total mercury amount emitted from the recycling process system. Hence, it was estimated that the MFA of the total mercury amount obtained from the vapor phase and the recycling materials of 1 ton of SFLs using the recycling process system was 80.175 g.
Mercury distribution and hazardous characteristics of major components from SCFLs (Spent compact fluorescent lamps)for 3 lamp manufactures (A, B, C) are estimated by the analysis of mercury concentration and leaching tests such asKorean Extraction Test (KET) and Toxicity Characteristic Leaching Procedure (TCLP). SCFLs can be separated into glasstube, phosphor powder, metals, ballast, plastics, and binder. Through the analysis of mercury in major components forSCFL, mercury concentration in phosphor powder is much higher than that in other components regardless manufacturesof lamp. Also, mercury concentration in phosphor powder is dependent of the manufactures of lamp. From the leachingtests, all components except phosphor powder from 3 lamp manufactures are verified to be non-hazardous waste becauseall leaching concentrations are below the regulatory level. However, the leaching concentration of mercury in phosphorpowder of SCFLs is higher than the regulatory level in both KET and TCLP regardless manufactures of lamp. Hence,phosphor powder should be managed as a hazardous waste and should be separately managed to control mercury.
The estimated that 114 million units of fluorescent lamp are sold every year, and that 70% or more spent fluorescent lamps (SFLs) are generated at business sites. According to Korea Lighting Recycling Corporation, recycled amount of SFLs selected as EPR (Extended Producer Responsibility) items from 2004 has been improved from 35,250,000 units in 2010 to 37,950,000 units in 2011, which recorded the greatest amount. Based on the year 2011, SFLs have been recycled by 31.5%, but their recycled rate is insufficient yet, compared to the recycling rate of metal cans or glass bottles, which are about 80%. The base cap of SFLs as a raw material was used in this experiment. Base cap contains an insulation sieve plate, aluminum cap, copper terminal, tempered glass, filament, and copper/iron mixed wire that goes through this glass. In order to protect a filament that is made up of tungsten for the electricity to flow, circular plate consisted of iron encloses the filament. Separating apparatus of SFL base cap used in this experiment is a device which has used impact crushing technique using hammer, screen separation and magnetic separation for the purpose of recovering aluminum, copper and iron contained in SFL. Impact hammer crusher, a device that separates aluminum from other materials by hammer impaction on the base cap that is separated by end-cutting, causes a significant reduction for other materials to be included in the collectible materials by separating aluminum, copper and iron from the base cap by using hammer crusher at 3 stages. Iron was collected by using a magnetic separation unit and the collectible materials were separated into aluminum with larger particles, and glass and other materials with smaller particles by screen separation. The separation performance was estimated for the 3 stages of hammer crusher unit to recover aluminum from the base-cap of SFLs and the separation performances are 94% at the 1st stage, 97% at the 2nd stage, and 98% at the 3rd stage, respectively.
Linear type SFL (spent fluorescent lamp) can be classified by 3-banded lamp and general lamp. Linear type SFL is separated by the end-cutting technique to examine the distribution of mercury in the major components such as base cap, glass part and phosphor powder. In this study, the concentration of mercury is analyzed by DMA (Direct Mercury Analysis) method for major components in linear type SFL. From the results of mercury distribution for 3 companies, the concentration of mercury in 3-banded lamp is less than that in general lamp. And phosphor powder has greater than 80% of total mercury amount in SFL and the mercury concentration in phosphor powder is measured between 1,250 ppm and 1,740 ppm. The mercury concentration in phosphor powder can be changed by the type of lamp, company, and period of usage. KET and TCLP are carried out for phosphor powder, glass, and base cap to estimate the hazardous characteristic. From the results of KET and TCLP test for general lamp and 3-banded lamp, phosphor powder from general lamp and 3-banded lamp should be controlled separately by stabilization or other methods to reuse as a renewable material because the phosphor powder is determined as a hazardous waste.