일반 소형 형광등(Compact Florescent Lamp; CFL)(20W기준)에는 약 10%의 철금속(ferrous metal)이 존재한다. 철금속은 ‘리사이클링에 의한 생산량’ 을 ‘광석에 의한 생산량’ 으로 나눈 값인 리사이클링강도가 0.84로 타소재 알루미늄 0.39, 구리 0.08, 티타늄 0.02인 데 비해 압도적으로 높으며 철금속을 재활용하면 광물로부터 직접 철금속을 만드는 공정에 비해 이산화탄소 82%, 질소산화물 88.9%, 황산화물 94.7%을 줄일 수 있다. 또한 자연을 비교적 적게 파괴하면서도 쓰레기를 거의 남기지 않는 친환경적인 소재로 다른 소재 대신 철금속을 사용하면 사용할수록 환경보존에 도움이 되며 재활용도 용이해 경제성이 매우 뛰어나다. 본 연구는 폐형광등의 재활용 과정의 일부인 자력을 이용하여 자성물질인 철금속을 선별 및 회수 목적으로 자력 선별기를 개발하는 것이다. 수은이 제거된 폐소형 형광등(CFL)을 자력 선별기에 투입한 후 자력을 이용해 물리적으로 철금속을 단시간에 효과적으로 선별 및 회수할 수 있는 방법이다. 본 연구에서는 자력 선별기에 의한 시료의 투입속도에 따른 철금속의 선별 및 회수를 모니터링 하여 자력선별기의 선별효율을 평가하고자 하였다.

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.

Compact fluorescent lamps are strongly encouraged to manage separately in Korea because Compact fluorescent lamps contain mercury. Compact fluorescent lamps have managed as household waste in Korea, however, even though Compact fluorescent lamps contains hazardous material such as mercury. The aim of management of Compact fluorescent lamps separately is to reduce the release of mercury from Compact fluorescent lamp lamps into the environment and to reuse of the glass, metals and other components of Compact fluorescent lamps. The amount of mercury in a fluorescent lamps varies, depending on the type of lamp and manufacturer, but typically ranges between 5 milligrams and 30 milligrams. The mercury content of fluorescent lamps has been reported to be between 0.72 and 115 mg/lamp with an average mercury content of about 30 mg/lamp in 1994. Although manufacturers have greatly reduced the amount of mercury used in fluorescent lamps over the past 20years, mercury is an essential component to fluorescent lamps and can’t be eliminated completely in lamps. In the crushing process, CFL(compact fluorescent lamp) is separated into glass, plastic, ballast, phosphor powder and vapor. Using the crushing technique, concentration of mercury vapor emission from CFL is evaluated. Through the experiments, the efficiency of the crushing and separation for the unit is estimated by measuring the volume of CFL. In this study, the concentration of mercury is analyzed by MVI(Mercury Vapor Indicator) method for vapor in CFL. From the results of mercury distribution for 3 companies, the concentration of mercury in compact fluorescent lamp is less than that in the other type lamps. And phosphor powder has greater than 99% of total mercury amount in CFL and the mercury concentration in phosphor powder is measured between 1,008ppm and 1,349ppm. The mercury concentration in phosphor powder can be changed by the type of company and period of usage. KET and TCLP are carried out for phosphor powder, glass, plastic, ballast and base cap to estimate the hazardous characteristic. From the results of KET and TCLP test for CFL, phosphor powder from CFL 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. From the results of characteristics of CFL, the carbonization system of CFL should be carried out in the temperature of less than 350℃. The amount of mercury in a fluorescent lamps varies, depending on the type of lamp and manufacturer, but typically ranges between 5 milligrams and 30 milligrams. The mercury content of Compact fluorescent lamps has been reported to be between 0.72 and 115 mg/lamp with an average mercury content of about 30 mg/lamp in 1994. Although manufacturers have greatly reduced the amount of mercury used in fluorescent lamps over the past 20years, mercury is an essential component to fluorescent lamps and can’t be eliminated completely in lamps. In Korea, demonstration for recycling of U type lamps had once begun in the area of Seoul Metropolitan, 2000. In 2004, U type lamps was included as an item in EPR(Extended Producer Responsibility) system. According to Korea Lighting Recycling Association, approximately 38 million Compact fluorescent lamps were recycled in Korea, 2011 because 3 recycling facilities for Compact fluorescent lamps are operated in Korea. Recycling rate of Compact fluorescent lamps in Korea is about 31.0% but about 70% of Compact fluorescent lamps may not manage properly. Hence, discarded lamps release approximately 2 to 3 tons of mercury per year into the environment[6]. In USA, Compact fluorescent lamps has controlled by Universal Waste Rule and merchandises containing mercury prohibited to produce. Also, MEBA(Mercury Export Ban Act) is activated in USA from 2013. According to Association of Lighting and Mercury Recycler, member companies accomplish about 85% of the lamp recycling done each year. In Germany, best available technology (BAT) system for recycling of Compact fluorescent lamps is established and about 20 companies are involved in recycling of Compact fluorescent lamps. In 1994, approximately 70-80% of total Compact fluorescent lamps are recycled in 1994 and Compact fluorescent lamps was included as an item in EPR(Extended Producer Responsibility) system in 1996. In Sweden, MRT System, which was developed by Lumalampan, separated mercury from Compact fluorescent lamps by distillation operation, 1979. Reverse route collection system is active to improve the collection of Compact fluorescent lamps. Compact fluorescent lamps was included as an item in EPR(Extended Producer Responsibility) system in 2001. In Austria, about 40 companies are involved in recycling of Compact fluorescent lamps to recycle glass and ferrous metals. And wastes containing mercury are treated in landfill site by using special container [7,8]. In this study, Compact fluorescent lamps is cut by a end-cutting unit with a cam crusher and base-cap is separated from glass part. In the end-cutting unit, a vacuum system is operating to collect mercury vapor to prevent leaking from the end-cutting unit. First of all, characteristics and major composition of Compact fluorescent lamps are estimated. Through the experiments, it is measured mercury concentration in the parts of Compact fluorescent lamps such as glass tube, phosphor powder, and base cap after separation in the end-cutting unit. Also, it is evaluated mercury emission from Compact fluorescent lamps by measuring the concentration of effluent gas in the end-cutting unit with changing flow rate. Finally, Korea Extraction Method (KET) and TCLP(Toxicity Characteristic Leaching Procedure) test are applied to phosphor powder to verify that phosphor powder is a hazardous waste [9].