Gypsum recycling

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Gypsum recycling is the process of turning gypsum waste (from construction) into recycled gypsum, thereby generating a raw material that can replace virgin gypsum raw materials in the manufacturing of new products.

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Gypsum waste definition and types

Gypsum waste primarily consists of waste from gypsum boards, which are wall or ceiling panels made of a gypsum core between paper lining. Such boards are also referred to as sheetrock, plasterboards, drywall, wallboards and gyprock. Gypsum waste in some countries also consists of gypsum blocks and plaster, among others.

Three main types of gypsum waste based on their origin can be distinguished: [1]

Gypsum waste from the manufacturing of gypsum products.
This waste, which arises at the industrial gypsum production sites, consists of rejects and non-spec materials generated during the manufacturing of gypsum products. The recycling of this waste stream is usually part of the waste avoidance activity of the gypsum plants. The waste is referred to as gypsum manufacturing or production waste and the recycled gypsum obtained from the recycling of this is known as “production waste derived recycled gypsum”. [2]
Gypsum waste from new construction.
Gypsum waste from new construction activities is typically a clean waste, and primarily consists of off-cuts of plasterboard (drywall, wallboard or gyprock) when the boards have been cut to fit the dimensions of the wall or ceiling. The waste may constitute 15% of the gypsum materials used on the site. Such waste is generally referred to as new construction gypsum waste, and can be reduced by ordering boards “made-to-measure”, but in most markets less than 10% of all orders are “made-to-measure”.
Gypsum waste from demolition and reconstruction
This waste arises when already installed plasterboards (drywalls, wallboards or gyprock boards), that usually have been installed many years ago, are taken out in connection with that the building is demolished or renovated. For this reason some refer to this waste as “old gypsum waste”, whereas the trade usually refer to this waste as “demolition waste”. Different from the two other types of gypsum waste described above, this type of gypsum waste from renovation, refurbishment and demolition works is more likely to present a certain degree of contamination, which can be in the form of nails, screws, wood, insulation, wall coverings etc. For this waste to be recyclable it is required that the equipment processing the waste is capable of separating such contamination from the gypsum to arrive at a pure recycled gypsum. New construction and demolition gypsum waste are both generated after the gypsum products have left the manufacturer, and together these two waste types are referred to as post consumer gypsum waste. [2]

Gypsum recycling process

Gypsum waste can be turned into recycled gypsum by processing the gypsum waste in such a way that the contaminants are removed and the paper facing of the plasterboard is separated from the gypsum core through mechanical processes including grinding and sieving in specialised equipment. Gypsum waste such as gypsum blocks and plaster do not require the removal of paper, as they are not made with paper from the beginning. It is typical for the gypsum recyclers to accept up to 3 per cent of contamination from other materials. The professional recyclers are capable of handling gypsum waste with nails and screws, wall coverings etc.

Why should gypsum waste be recycled?

Gypsum materials consist of calcium sulfate dihydrate (CaSO4·2H2O). Sulfate-reducing bacteria convert sulfates to toxic hydrogen sulphide gas; they are killed by exposure to air, but the moist, airless, carbon-containing environment in a landfill is a good habitat for them. So gypsum put into landfill will decompose, releasing up to a quarter of its weight in hydrogen sulfide. [3] Moreover, methanogenic bacteria also thrive in such an environment, and convert the paper in the plasterboard to methane gas which is a potent greenhouse gas. [4] [5]

Recycling gypsum waste also reduces the need for the quarrying and production of virgin gypsum raw materials.

Recycling one ton of the ordinary gypsum will save 1,000 pounds of black alkali, 1 ton of lactic acid and 500 kwh of energy.[ citation needed ]

Recycling one metric ton of gypsum will save 28 kwh of energy and 4 pounds of aluminium.[ citation needed ]

Rationale for choosing closed loop recycling

Gypsum is fully and eternally recyclable [6] and, as a consequence, gypsum waste is one of the few construction materials for which closed loop recycling is possible.

Closed loop recycling of gypsum products involves the collection and processing of the gypsum waste, and the delivery of the obtained recycled gypsum to the manufacturer of gypsum products. It is therefore essential that the recycled gypsum achieves a pre-determined quality suitable for the manufacturing of new gypsum products. Presently there is no European or American standard pre-determining the recycled gypsum's quality and the criteria vary from plant to plant.

By choosing closed loop recycling the need for manufacturers to acquire virgin gypsum is reduced, contributing therefore to promote a sustainable manufacturing process.

The most advanced plants, and most of these are found in the Nordic countries in Europe, have substituted up to 30 per cent of virgin gypsum raw materials with recycled gypsum. [7]

Gypsum recycling in Europe

Gypsum recycling in Europe was started by the Danish company Gypsum Recycling International A/S Archived 2013-12-02 at the Wayback Machine in Denmark, in 2001. After a few years the recycling system received waste from approximately 85 per cent of all public civic amenity/recycling centres and a recycling rate of 60 per cent of all gypsum waste was achieved. [8] The system has been exported to cover other European countries. Today also new recyclers have emerged and gypsum recycling systems have been introduced in more countries, like the UK, France and in the Benelux, but the highest recycling rates for gypsum waste are still found in Denmark, Norway and Sweden. January 1, 2013 the European Life + project “Gypsum to Gypsum” [9] started, with the overall aim of transforming the gypsum demolition waste market to achieve higher recycling rates of gypsum waste, thereby helping to achieve a resource efficient economy. [1] One of the drivers for the project [1] is the target set by the European Union to achieve that 70 per cent of construction and demolition waste is recycled by 2020. [10]

Gypsum recycling in North America

Urban Gypsum Recycling Urban Gypsum is a division of Laneco, Inc. and provides gypsum wallboard recycling services for the Pacific Northwest of the United States. This recovered gypsum is then distributed to agricultural and industrial customers in the region keeping the wallboard from ending up in the landfill.

New West Gypsum Recycling began recycling of wallboard waste in Canada in 1985. The recycled material is a blend of pre- and post-consumer, wet and dry gypsum waste that is a source of raw material for use in the manufacture of new drywall products. Gypsum Agri-cycle is one of the first companies to recycle drywall in the USA. Gypsum Agri-cycle is another North American recycler of new construction drywall located in Pennsylvania. Pennsylvania does not allow Gypsum Agri-cycle to recycle demolition drywall.

Zanker Recycling began recycling gypsum in the form of sheetrock in 1999. In the recycling process, materials such as wood, metals, and trash are removed on-site where a dozer is used to crush the materials.

American Gypsum Recycling American Gypsum Recycling was founded in 2018 by Chris Stapleton. His vision for the company is to transform the Northwest drywall waste stream into a valuable product for agriculture and industry.

USA Gypsum located in Denver, PA provides both closed loop recycling and up-cycling reclaimed gypsum to higher value gypsum products such as agricultural gypsum. [11]

See also

Related Research Articles

<span class="mw-page-title-main">Gypsum</span> Soft calcium sulfate mineral

Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula CaSO4·2H2O. It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, drywall and blackboard or sidewalk chalk. Gypsum also crystallizes as translucent crystals of selenite. It forms as an evaporite mineral and as a hydration product of anhydrite. The Mohs scale of mineral hardness defines gypsum as hardness value 2 based on scratch hardness comparison.

<span class="mw-page-title-main">Drywall</span> Panel made of gypsum, used in interior construction

Drywall is a panel made of calcium sulfate dihydrate (gypsum), with or without additives, typically extruded between thick sheets of facer and backer paper, used in the construction of interior walls and ceilings. The plaster is mixed with fiber ; plasticizer, foaming agent; and additives that can reduce mildew, flammability, and water absorption.

<span class="mw-page-title-main">USG Corporation</span> Manufacturing company

USG Corporation, also known as United States Gypsum Corporation, is an American company which manufactures construction materials, most notably drywall and joint compound. The company is the largest distributor of wallboard in the United States and the largest manufacturer of gypsum products in North America. It is also a major consumer of synthetic gypsum, a byproduct of flue-gas desulfurization. Its corporate offices are located at 550 West Adams Street in Chicago, Illinois.

<span class="mw-page-title-main">BPB plc</span> British building materials business

BPB Ltd was a British building materials business. It once was a constituent of the FTSE 100 Index. In 2005, the company was purchased by Saint-Gobain of France. The company's subsidiary British Gypsum, which was the UK operating arm of the company, operates as a subsidiary of Saint-Gobain, with five manufacturing sites in Britain as of 2012.

<span class="mw-page-title-main">Glass recycling</span> Processing of waste glass into usable products

Glass recycling is the processing of waste glass into usable products. Glass that is crushed or imploded and ready to be remelted is called cullet. There are two types of cullet: internal and external. Internal cullet is composed of defective products detected and rejected by a quality control process during the industrial process of glass manufacturing, transition phases of product changes and production offcuts. External cullet is waste glass that has been collected or reprocessed with the purpose of recycling. External cullet is classified as waste. The word "cullet", when used in the context of end-of-waste, will always refer to external cullet.

<span class="mw-page-title-main">Biodegradable waste</span> Organic matter that can be broken down

Biodegradable waste includes any organic matter in waste which can be broken down into carbon dioxide, water, methane, compost, humus, and simple organic molecules by micro-organisms and other living things by composting, aerobic digestion, anaerobic digestion or similar processes. It mainly includes kitchen waste, ash, soil, dung and other plant matter. In waste management, it also includes some inorganic materials which can be decomposed by bacteria. Such materials include gypsum and its products such as plasterboard and other simple sulfates which can be decomposed by sulfate reducing bacteria to yield hydrogen sulfide in anaerobic land-fill conditions.

Landfill mining and reclamation (LFMR) is a process which excavates and processes solid wastes which have previously been landfilled. The process aims to reduce the amount of landfill mass encapsulated within the closed landfill and/or temporarily remove hazardous material to allow protective measures to be taken before the landfill mass is replaced. In the process, mining recovers valuable recyclable materials, a combustible fraction, soil, and landfill space. The aeration of the landfill soil is a secondary benefit with regard to the landfill's future use. The combustible fraction is useful for power generation. The overall appearance of the landfill mining procedure is a sequence of processing machines laid out in a functional conveyor system. The operating principle is to excavate, sieve and sort the landfill material.

<span class="mw-page-title-main">Construction waste</span> Unwanted material produced directly or incidentally by the construction industries

Construction waste or debris is any kind of debris from the construction process. Different government agencies have clear definitions. For example, the United States Environmental Protection Agency EPA defines construction and demolition materials as “debris generated during the construction, renovation and demolition of buildings, roads, and bridges.” Additionally, the EPA has categorized Construction and Demolition (C&D) waste into three categories: non-dangerous, hazardous, and semi-hazardous.

<span class="mw-page-title-main">Gypsum, Ohio</span> Unincorporated community in Ohio, United States

Gypsum is an unincorporated community in eastern Portage Township, Ottawa County, Ohio, United States. It has a post office with the ZIP code 43433.

<span class="mw-page-title-main">Kalundborg Eco-industrial Park</span> Industrial symbiosis network in Kalundborg, Denmark

Kalundborg Eco-Industrial Park is an industrial symbiosis network located in Kalundborg, Denmark, in which companies in the region collaborate to use each other's by-products and otherwise share resources.

<span class="mw-page-title-main">Waste</span> Unwanted or unusable materials

Waste are unwanted or unusable materials. Waste is any substance discarded after primary use, or is worthless, defective and of no use. A by-product, by contrast is a joint product of relatively minor economic value. A waste product may become a by-product, joint product or resource through an invention that raises a waste product's value above zero.

<span class="mw-page-title-main">Magnesium oxide wallboard</span>

Magnesium oxide, more commonly called magnesia, is a mineral that when used as part of a cement mixture and cast into thin cement panels under proper curing procedures and practices can be used in residential and commercial building construction. Some versions are suitable for general building uses and for applications that require fire resistance, mold and mildew control, as well as sound control applications. Magnesia board has strength and resistance due to very strong bonds between magnesium and oxygen atoms that form magnesium oxide crystals.

<span class="mw-page-title-main">Demolition waste</span> Waste debris from destruction of buildings, roads, bridges, or other structures

Demolition waste is waste debris from destruction of buildings, roads, bridges, or other structures. Debris varies in composition, but the major components, by weight, in the US include concrete, wood products, asphalt shingles, brick and clay tile, steel, and drywall. There is the potential to recycle many elements of demolition waste.

<span class="mw-page-title-main">Knauf</span>

Knauf Gips KG is a multinational, family-owned company based in Iphofen, Germany, well known for drywall gypsum boards, founded in 1932. The company is a producer of building materials and construction systems comprising construction materials for drywall construction, plasterboard, cement boards, mineral fibre acoustic boards, dry mortars with gypsum for internal plaster and cement-based external plaster and insulating materials; glass wool, stone wool and other insulation materials under the company Knauf Insulation.

Products made from a variety of materials can be recycled using a number of processes.

Resource recovery is using wastes as an input material to create valuable products as new outputs. The aim is to reduce the amount of waste generated, thereby reducing the need for landfill space, and optimising the values created from waste. Resource recovery delays the need to use raw materials in the manufacturing process. Materials found in municipal solid waste, construction and demolition waste, commercial waste and industrial wastes can be used to recover resources for the manufacturing of new materials and products. Plastic, paper, aluminium, glass and metal are examples of where value can be found in waste.

<span class="mw-page-title-main">Gypsum block</span>

Gypsum block is a massive lightweight building material composed of solid gypsum, for building and erecting lightweight, fire-resistant, non-load bearing interior walls, partition walls, cavity walls, skin walls, and pillar casing indoors. Gypsum blocks are composed of gypsum, plaster, water and in some cases additives like vegetable or wood fiber for greater strength. Partition walls, made from gypsum blocks, require no sub-structure for erection and gypsum adhesive is used as bonding agent, not standard mortar. Because of this fundamental difference, gypsum blocks shouldn't be confused with the thinner plasterboard used for paneling stud walls.

<span class="mw-page-title-main">Grenzebach BSH</span>

Grenzebach BSH (GmbH) was established following the take-over of Babcock-BSH GmbH by Grenzebach Maschinenbau GmbH. Grenzebach BSH GmbH has its registered office in Bad Hersfeld, Germany, and has been a member of the Grenzebach group since October 2002. The company employs some 350 people and at the Bad Hersfeld location continues its predecessor's activities as a supplier of equipment and services for the wood processing and building materials industries as well as the process technology sector. Its offices and workshops were first located in buildings that in part dated back to the old Schilde AG. Beginning in the summer of 2007, engineering and administration were the first departments to move into a new office building located at Gewerbepark Hohe Luft, a business park at the periphery of Bad Hersfeld. Construction of a new factory building right next to the offices began in 2008 and was completed in 2009. Manufacturing and the remaining departments such as R&D and logistics then also moved in from mid-2009. By the end of 2009 all buildings on the former Schilde premises in the town centre were vacated and handed back their owner, the town of Bad Hersfeld.

<span class="mw-page-title-main">Gypsum Recycling International</span>

Gypsum Recycling International A/S (GRI) is a recycling company based in Nærum, Rudersdal Municipality, Denmark. GRI offers a system for the recycling of gypsum and plasterboard/drywall waste.

<span class="mw-page-title-main">Clay panel</span> Building material made of clay with some additives

Clay panel or clay board is a panel made of clay with some additives. The clay is mixed with sand, water, and fiber, typically wood fiber, and sometimes other additives like starch. Most often this means employing the use of high-cellulose waste fibres. To improve the breaking resistance clay boards are often embedded in a hessian skin on the backside or similar embeddings.

References

  1. 1 2 3 European Commission. http://ec.europa.eu/environment/life/project/Projects/index.cfm?fuseaction=search.dspPage&n_proj_id=4191 Retrieved 3 October 2013
  2. 1 2 WRAP, Technical Report. Life Cycle Assessment of Plasterboard. 2008. http://www2.wrap.org.uk/downloads/Life_Cycle_Assessment_of_Plasterboard.2a99ccc6.5313.pdf%5B%5D Retrieved 26 September 2013.
  3. ↑ Recycling Council of British Columbia. Why can't I put my leftover gyproc/drywall in the garbage? Retrieved from <http://rcbc.bc.ca/education/faqs/hazard9 Archived 2013-10-21 at the Wayback Machine >
  4. ↑ Environmental Protection Agency. State of Ohio. Fact Sheet: Methane and Hydrogen Sulfide Gases at C&DD Landfills. Retrieved from <http://epa.ohio.gov/portals/34/document/guidance/gd_669.pdf>
  5. ↑ Khalil, M. A. K. (1999). "Non-Co2Greenhousegases Intheatmosphere". Annual Review of Energy and the Environment . 24: 645–661. doi: 10.1146/annurev.energy.24.1.645 .
  6. ↑ EUROGYPSUM, Environmental and Raw Material Committee. Factsheet on: What is gypsum? http://www.eurogypsum.org/_uploads/dbsattachedfiles/whatisgypsum.pdf Archived 2013-12-02 at the Wayback Machine [ dead link ]
  7. ↑ Saint-Gobain Gyproc Finland. Letter written by the Plant Director. June 2013
  8. ↑ WRAP. Plasterboard Case Study. International practice in plasterboard recycling: Denmark. Gypsum Recycling International A/S.
  9. ↑ Gypsum to Gypsum: From Production to Recycling, a Circular Economy for the European Gypsum Industry with the Demolition and Recycling Industry. LIFE11 ENV/BE/001039. <http://gypsumtogypsum.org/ Archived 2013-12-03 at the Wayback Machine > Retrieved 26 September 2013.
  10. ↑ Directive 2008/98/EC of the European Parliament and of the Council of 19 November 2008 on waste and repealing certain Directives
  11. ↑ "Home". usagypsum.com.
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