Fluorescent lamp recycling

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Fluorescent lamp recycling is the recovery of the materials of a spent fluorescent lamp for the manufacture of new products.

Contents

Overview

Glass tubing can be turned into new glass articles, brass and aluminum in end caps can be reused, the internal coating can be reprocessed for use in paint pigments, and the mercury contained in the lamp can be reclaimed and used in new lamps. [1] In the United States, about 620 million fluorescent lamps are discarded annually; proper recycling of a lamp prevents emission of mercury into the environment, and is required by most states for commercial facilities. [2] The primary advantage of recycling is diversion of mercury from landfill sites, but the actual scrap value of the materials salvaged from a discarded lamp is often insufficient to offset the cost of recycling. [3]

Mercury in lamps

The amount of mercury in a fluorescent lamp varies from 3 to 46 mg, depending on lamp size and age. [4] Newer lamps contain less mercury and the 3–4 mg versions are sold as low-mercury types. A typical 2006-era 4 ft (122 cm) T-12 fluorescent lamp (i.e. F34T12) contains about 5 milligrams of mercury. [5] In early 2007, the National Electrical Manufacturers Association in the US announced that "Under the voluntary commitment, effective April 15, 2007, participating manufacturers will cap the total mercury content in CFLs under 25 watts at 5 milligrams (mg) per unit. CFLs that use 25 to 40 watts of electricity will have total mercury content capped at 6 mg per unit." [6]

Only a few tenths of a milligram of mercury are required to maintain the vapor, but lamps must include more mercury to compensate for the part of mercury absorbed by internal parts of the lamp and no longer available to maintain the arc. Manufacturing processes have been improved to reduce the handling of liquid mercury during manufacture and improve accuracy of mercury dosing. [7] :194

Mercury-free discharge lamps have considerably lower production of visible light, reduced to about half; thus, mercury remains an essential component of efficient fluorescent lamps. [7] :192

Broken lamps

A broken fluorescent tube will release its mercury content. Safe cleanup of broken fluorescent bulbs differs from cleanup of conventional broken glass or incandescent bulbs, avoiding the use of vacuum cleaners, in favour of sticky tape to recover small particles, and ensuring that fans and air conditioning are turned off. [8] [9] Approximately 99% of the mercury is typically contained in the phosphor, especially on lamps that are near their end of life. [10]

Phosphors

Lamps made up to the 1940s used toxic beryllium compounds, which were implicated in the deaths of factory workers. [11] :Chapter 7 [12] Today it is very unlikely that one would encounter any such lamps. [13]

Other toxic elements such as arsenic, cadmium, and thallium were formerly used in phosphor manufacture. Modern halophosphate phosphors resemble the chemistry of tooth enamel.[ further explanation needed ] The rare-earth doped phosphors are not known to be harmful. [7] :195

Mercury containment

When a modern fluorescent tube is discarded, the main concern is the mercury, which is a significant toxic pollutant. One way to avoid releasing mercury into the environment is to combine it with sulfur to form mercury sulfide, which will prevent vapor release and is insoluble in water. One advantage of sulfur is its low cost. The reaction is shown with the equation:

Hg + S → HgS

The easiest way to combine sulfur and mercury is to cover a group of fluorescent tubes with sulfur dust (sometimes called "flowers of sulfur") and to break the tubes; when the glass fragments are put into a bag to continue with the reaction, the mercury will combine with sulfur without any other action. The glass can be recycled where an appropriate facility exists. A quantity of 25 kilograms (55 lb) of dust sulfur is enough for 1000 tubes.[ citation needed ]

Disposal methods

The disposal of phosphor and mercury toxins from spent tubes can be an environmental hazard. Governmental regulations in many areas require special disposal of fluorescent lamps separate from general and household wastes. For large commercial or industrial users of fluorescent lights, recycling services are available in many nations, and may be required by regulation. In some areas, recycling is also available to consumers.

Spent fluorescent lamps are typically packaged prior to transport to a recycling facility in one of three ways: boxed for bulk pickup, by using a prepaid lamp recycling box, or crushed onsite before pickup. A fluorescent lamp crusher can attach directly to a disposal drum and isolate the dust and mercury vapor.[ citation needed ] In some states, drum-top crushers and end-user crushing of lamps are not allowed.[ why? ] Minnesota Department of Health Drum Top Bulb Crusher Demonstration Archived 2013-06-27 at the Wayback Machine Disposal methods are regulated at both the state and federal level.

Proper recycling of fluorescent lamps can reduce risk of human exposure to mercury.

Related Research Articles

<span class="mw-page-title-main">Electric light</span> Device for producing light from electricity

An electric light, lamp, or light bulb is an electrical component that produces light. It is the most common form of artificial lighting. Lamps usually have a base made of ceramic, metal, glass, or plastic, which secures the lamp in the socket of a light fixture, which is often called a "lamp" as well. The electrical connection to the socket may be made with a screw-thread base, two metal pins, two metal caps or a bayonet mount.

<span class="mw-page-title-main">Timeline of lighting technology</span>

Artificial lighting technology began to be developed tens of thousands of years ago and continues to be refined in the present day.

<span class="mw-page-title-main">Fluorescent lamp</span> Lamp using fluorescence to produce light

A fluorescent lamp, or fluorescent tube, is a low-pressure mercury-vapor gas-discharge lamp that uses fluorescence to produce visible light. An electric current in the gas excites mercury vapor, which produces short-wave ultraviolet light that then causes a phosphor coating on the inside of the lamp to glow. A fluorescent lamp converts electrical energy into useful light much more efficiently than an incandescent lamp. The typical luminous efficacy of fluorescent lighting systems is 50–100 lumens per watt, several times the efficacy of incandescent bulbs with comparable light output. For comparison, the luminous efficacy of an incandescent bulb may only be 16 lumens per watt.

<span class="mw-page-title-main">Blacklight</span> Light fixture that emits long-wave ultraviolet light and very little visible light

A blacklight, also called a UV-A light, Wood's lamp, or ultraviolet light, is a lamp that emits long-wave (UV-A) ultraviolet light and very little visible light. One type of lamp has a violet filter material, either on the bulb or in a separate glass filter in the lamp housing, which blocks most visible light and allows through UV, so the lamp has a dim violet glow when operating. Blacklight lamps which have this filter have a lighting industry designation that includes the letters "BLB". This stands for "blacklight blue". A second type of lamp produces ultraviolet but does not have the filter material, so it produces more visible light and has a blue color when operating. These tubes are made for use in "bug zapper" insect traps, and are identified by the industry designation "BL". This stands for "blacklight".

<span class="mw-page-title-main">Gas-filled tube</span> Assembly of electrodes at either end of an insulated tube filled with gas

A gas-filled tube, also commonly known as a discharge tube or formerly as a Plücker tube, is an arrangement of electrodes in a gas within an insulating, temperature-resistant envelope. Gas-filled tubes exploit phenomena related to electric discharge in gases, and operate by ionizing the gas with an applied voltage sufficient to cause electrical conduction by the underlying phenomena of the Townsend discharge. A gas-discharge lamp is an electric light using a gas-filled tube; these include fluorescent lamps, metal-halide lamps, sodium-vapor lamps, and neon lights. Specialized gas-filled tubes such as krytrons, thyratrons, and ignitrons are used as switching devices in electric devices.

<span class="mw-page-title-main">High-intensity discharge lamp</span> Type of electric lamp/bulb

High-intensity discharge lamps are a type of electrical gas-discharge lamp which produces light by means of an electric arc between tungsten electrodes housed inside a translucent or transparent fused quartz or fused alumina arc tube. This tube is filled with noble gas and often also contains suitable metal or metal salts. The noble gas enables the arc's initial strike. Once the arc is started, it heats and evaporates the metallic admixture. Its presence in the arc plasma greatly increases the intensity of visible light produced by the arc for a given power input, as the metals have many emission spectral lines in the visible part of the spectrum. High-intensity discharge lamps are a type of arc lamp.

<span class="mw-page-title-main">Mercury-vapor lamp</span> Light source using an electric arc through mercury vapor

A mercury-vapor lamp is a gas-discharge lamp that uses an electric arc through vaporized mercury to produce light. The arc discharge is generally confined to a small fused quartz arc tube mounted within a larger soda lime or borosilicate glass bulb. The outer bulb may be clear or coated with a phosphor; in either case, the outer bulb provides thermal insulation, protection from the ultraviolet radiation the light produces, and a convenient mounting for the fused quartz arc tube.

<span class="mw-page-title-main">Compact fluorescent lamp</span> Fluorescent lamps with folded tubes, often with built-in ballast

A compact fluorescent lamp (CFL), also called compact fluorescent light, energy-saving light and compact fluorescent tube, is a fluorescent lamp designed to replace an incandescent light bulb; some types fit into light fixtures designed for incandescent bulbs. The lamps use a tube that is curved or folded to fit into the space of an incandescent bulb, and a compact electronic ballast in the base of the lamp.

<span class="mw-page-title-main">Metal-halide lamp</span> Type of lamp

A metal-halide lamp is an electrical lamp that produces light by an electric arc through a gaseous mixture of vaporized mercury and metal halides. It is a type of high-intensity discharge (HID) gas discharge lamp. Developed in the 1960s, they are similar to mercury vapor lamps, but contain additional metal halide compounds in the quartz arc tube, which improve the efficiency and color rendition of the light. The most common metal halide compound used is sodium iodide. Once the arc tube reaches its running temperature, the sodium dissociates from the iodine, adding orange and reds to the lamp's spectrum from the sodium D line as the metal ionizes. As a result, metal-halide lamps have high luminous efficacy of around 75–100 lumens per watt, which is about twice that of mercury vapor lights and 3 to 5 times that of incandescent lights and produce an intense white light. Lamp life is 6,000 to 15,000 hours. As one of the most efficient sources of high CRI white light, metal halides as of 2005 were the fastest growing segment of the lighting industry. They are used for wide area overhead lighting of commercial, industrial, and public places, such as parking lots, sports arenas, factories, and retail stores, as well as residential security lighting, automotive headlamps and indoor cannabis grow operations.

<span class="mw-page-title-main">Induction lamp</span> Gas-discharge lamp using electric and magnetic fields to transfer energy to the gas inside

The induction lamp, electrodeless lamp, or electrodeless induction lamp is a gas-discharge lamp in which an electric or magnetic field transfers the power required to generate light from outside the lamp envelope to the gas inside. This is in contrast to a typical gas discharge lamp that uses internal electrodes connected to the power supply by conductors that pass through the lamp envelope. Eliminating the internal electrodes provides two advantages:

<span class="mw-page-title-main">Sulfur lamp</span> Lighting system

The sulfur lamp is a highly efficient full-spectrum electrodeless lighting system whose light is generated by sulfur plasma that has been excited by microwave radiation. They are a particular type of plasma lamp, and one of the most modern. The technology was developed in the early 1990s, but, although it appeared initially to be very promising, sulfur lighting was a commercial failure by the late 1990s. Since 2005, lamps are again being manufactured for commercial use.

<span class="mw-page-title-main">Tanning lamp</span> Device which produces ultraviolet light used for indoor tanning

Tanning lamps are the part of a tanning bed, booth or other tanning device which produces ultraviolet light used for indoor tanning. There are hundreds of different kinds of tanning lamps most of which can be classified in two basic groups: low pressure and high pressure. Within the industry, it is common to call high-pressure units "bulbs" and low-pressure units "lamps", although there are many exceptions and not everyone follows this example. This is likely due to the size of the unit, rather than the type. Both types require an oxygen free environment inside the lamp.

<span class="mw-page-title-main">LED lamp</span> Electric light that produces light using LEDs

An LED lamp or LED light is an electric light that produces light using light-emitting diodes (LEDs). LED lamps are significantly more energy-efficient than equivalent incandescent lamps and fluorescent lamps. The most efficient commercially available LED lamps have efficiencies exceeding 200 lumens per watt (lm/W) and convert more than half the input power into light. Commercial LED lamps have a lifespan several times longer than both incandescent and fluorescent lamps.

<span class="mw-page-title-main">Phase-out of incandescent light bulbs</span> For more energy-efficient alternatives

Various governments have passed legislation to phase out manufacturing or importation of incandescent light bulbs for general lighting in favor of more energy-efficient alternatives. The regulations are generally based on efficiency, rather than use of incandescent technology. However, it is not unlawful to continue to buy or sell existing bulbs, which are unregulated.

<span class="mw-page-title-main">Hazardous waste in the United States</span>

Under United States environmental policy, hazardous waste is a waste that has the potential to:

Electron-stimulated luminescence (ESL) is production of light by cathodoluminescence, i.e. by a beam of electrons made to hit a fluorescent phosphor surface. This is also the method used to produce light in a cathode ray tube (CRT). Experimental light bulbs that were made using this technology do not include magnetic or electrostatic means to deflect the electron beam.

<span class="mw-page-title-main">Plasma lamp</span> Type of electrodeless gas-discharge lamp

Plasma lamps are a type of electrodeless gas-discharge lamp energized by radio frequency (RF) power. They are distinct from the novelty plasma lamps that were popular in the 1980s.

A fluorescent lamp crusher is a device that crushes and stores spent fluorescent lamps prior to processing at a recycling facility, while controlling the release of mercury vapor emissions. Also known as drum-top crushing, this lamp disposal method is designed to reduce the storage, labor, and shipping costs of recycling lamps over other methods, as well as decrease the likelihood of mercury release during transport to a recycling facility. Fluorescent lamp crushers are designed for use primarily in commercial and institutional facility management contexts.

<span class="mw-page-title-main">Fluorescent lamps and health</span>

Fluorescent lamps have been suggested to affect human health in various ways.

References

  1. Fluorescent Lamp Stewardship Initiative, Alberta Environment, 2000, ISBN   0-7785-1730-6
  2. Release of Mercury from Broken Fluorescent Bulbs, State of New Jersey Division of Science Research and Technology, Feb. 2004, pg. 1
  3. Alberta Environment
  4. Page 183 of "Archived copy" (PDF). Archived from the original (PDF) on 2009-03-04. Retrieved 2009-11-08.{{cite web}}: CS1 maint: archived copy as title (link)
  5. "Lighting Design Lab Articles - Mercury in Fluorescent Lamps". Archived from the original on May 14, 2011.
  6. "NEMA Voluntary Commitment on Mercury in CFLs". Archived from the original on May 14, 2008.
  7. 1 2 3 Kane, Raymond; Sell, Heinz [editors] (2001). Revolution in lamps: a chronicle of 50 years of progress (2nd ed.). Lilburn, GA: Fairmont Press. ISBN   0-88173-378-4.{{cite book}}: |first2= has generic name (help)
  8. EPA (22 January 2013). "Cleaning Up a Broken CFL".
  9. "Low-energy bulb disposal warning". 5 January 2008.
  10. Floyd, et al. (2002), quoted on page 184 of Toolkit for identification and quantification of mercury releases (PDF) Archived March 4, 2009, at the Wayback Machine
  11. Rosner, David; Markowitz, Gerald [editors] (1987). Dying for work: workers' safety and health in twentieth-century America ([1. Dr]. ed.). Bloomington: Indiana University Press. ISBN   0-253-31825-4.{{cite book}}: |first2= has generic name (help)
  12. Beryllium toxicity and fluorescent lamp manufacture, retrieved June 7, 2008 Archived October 3, 2009, at the Wayback Machine
  13. General Electric Fluorescent Lamps TP 111R, Dec. 1978, says on pg. 23 that since 1949 GE lamps used relatively inert phosphates found to be safe in ordinary handling of either the intact or broken lamp.