An eddy current separator (ECS) is a machine that uses a powerful magnetic field to separate non-ferrous metals from an input waste or ore stream. The device makes use of eddy currents to effect the separation. Non-ferrous metals typically separated by an ECS include aluminum, copper and die-cast metals. [1]
In waste sorting of single-stream recycling at materials recovery facilities, ECS is used after the waste has passed through some arrangement of magnets to remove ferrous metals. Eddy current separators are typically used at the end of the waste material stream, since ferrous metals will become heated when exposed to an eddy current field, leading to potential damage to the eddy current separator. [2]
In mining, ECS is sometimes used to separate metals from mined ore. [3]
The eddy current separator is applied to a conveyor belt carrying a layer of mixed waste. At the end of the conveyor belt is an eddy current rotor. [4] Non-ferrous metals caught in the eddy current end up in a product bin, while other material falls off the belt due to gravity.
Eddy current separators may use a rotating drum with permanent magnets, or may use an electromagnet depending on the type of separator. [4]
U.S. patent 3,448,857A for a device using eddy currents to separate non-ferrous metals from non-metals was granted to William Benson and Thomas Falconer of Eriez Magnetics in 1969. [5]
A magnet is a material or object that produces a magnetic field. This magnetic field is invisible but is responsible for the most notable property of a magnet: a force that pulls on other ferromagnetic materials, such as iron, steel, nickel, cobalt, etc. and attracts or repels other magnets.
Recycling is the process of converting waste materials into new materials and objects. This concept often includes the recovery of energy from waste materials. The recyclability of a material depends on its ability to reacquire the properties it had in its original state. It is an alternative to "conventional" waste disposal that can save material and help lower greenhouse gas emissions. It can also prevent the waste of potentially useful materials and reduce the consumption of fresh raw materials, reducing energy use, air pollution and water pollution.
In electromagnetism, an eddy current is a loop of electric current induced within conductors by a changing magnetic field in the conductor according to Faraday's law of induction or by the relative motion of a conductor in a magnetic field. Eddy currents flow in closed loops within conductors, in planes perpendicular to the magnetic field. They can be induced within nearby stationary conductors by a time-varying magnetic field created by an AC electromagnet or transformer, for example, or by relative motion between a magnet and a nearby conductor. The magnitude of the current in a given loop is proportional to the strength of the magnetic field, the area of the loop, and the rate of change of flux, and inversely proportional to the resistivity of the material. When graphed, these circular currents within a piece of metal look vaguely like eddies or whirlpools in a liquid.
Scrap consists of recyclable materials, usually metals, left over from product manufacturing and consumption, such as parts of vehicles, building supplies, and surplus materials. Unlike waste, scrap has monetary value, especially recovered metals, and non-metallic materials are also recovered for recycling. Once collected, the materials are sorted into types – typically metal scrap will be crushed, shredded, and sorted using mechanical processes.
A materials recovery facility, materials reclamation facility, materials recycling facility or multi re-use facility is a specialized waste sorting and recycling system that receives, separates and prepares recyclable materials for marketing to end-user manufacturers. Generally, the main recyclable materials include ferrous metal, non-ferrous metal, plastics, paper, glass. Organic food waste is used to anaerobic digestion or composting. Inorganic inert waste is used to make building materials. Non-recyclable high calorific value waste is used to making RDF and SRF.
Industrial wastewater treatment describes the processes used for treating wastewater that is produced by industries as an undesirable by-product. After treatment, the treated industrial wastewater may be reused or released to a sanitary sewer or to a surface water in the environment. Some industrial facilities generate wastewater that can be treated in sewage treatment plants. Most industrial processes, such as petroleum refineries, chemical and petrochemical plants have their own specialized facilities to treat their wastewaters so that the pollutant concentrations in the treated wastewater comply with the regulations regarding disposal of wastewaters into sewers or into rivers, lakes or oceans. This applies to industries that generate wastewater with high concentrations of organic matter, toxic pollutants or nutrients such as ammonia. Some industries install a pre-treatment system to remove some pollutants, and then discharge the partially treated wastewater to the municipal sewer system.
Mineral processing is the process of separating commercially valuable minerals from their ores in the field of extractive metallurgy. Depending on the processes used in each instance, it is often referred to as ore dressing or ore milling.
A mechanical biological treatment (MBT) system is a type of waste processing facility that combines a sorting facility with a form of biological treatment such as composting or anaerobic digestion. MBT plants are designed to process mixed household waste as well as commercial and industrial wastes.
A waste autoclave is a form of solid waste treatment that uses heat, steam and pressure of an industrial autoclave in the processing of waste. Waste autoclaves process waste either in batches or in continuous-flow processes. In batch processes, saturated steam is pumped into the autoclave at temperatures around 160 °C, or 320 °F. The steam pressure in the vessel is maintained up to 6 bars (gauge) for a period of up to 45 minutes to allow the process to fully 'cook' the waste. The autoclave process gives a very high pathogen and virus kill rate, although the fibrous products which come from the process are susceptible to bacteria and fungus as they are high in starch, cellulose and amino acids. When designed for sterilizing waste containing mostly liquids, a waste autoclave is known as an Effluent Decontamination System.
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.
In the recent past the problem of removing the deleterious iron particles from a process stream had a few alternatives. Magnetic separation was typically limited and moderately effective. Magnetic separators that used permanent magnets could generate fields of low intensity only. These worked well in removing ferrous tramp but not fine paramagnetic particles. Thus high-intensity magnetic separators that were effective in collecting paramagnetic particles came into existence. These focus on the separation of very fine particles that are paramagnetic.
Sims Limited (formerly Sims Metal Management Limited) is a global environmental services conglomerate, operating through a number of divisions, with a focus on: (a) Ferrous and Non-ferrous metal recycling, (b) enterprise data destruction and cloud asset management (c) post-consumer electronic goods recycling and reuse, (d) municipal waste recycling, (e) gas to energy, and (f) waste to energy. Founded in 1917, its primary operations are located in the United States, Australia and the UK.
Single-stream recycling refers to a system in which all paper fibers, plastics, metals, and other containers are mixed in a collection truck, instead of being sorted by the depositor into separate commodities and handled separately throughout the collection process. In single-stream, both the collection and processing systems are designed to handle this fully commingled mixture of recyclables, with materials being separated for reuse at a materials recovery facility.
Magnetic separation is the process of separating components of mixtures by using a magnet to attract magnetic substances. The process that is used for magnetic separation separates non-magnetic substances from those which are magnetic. This technique is useful for the select few minerals which are ferromagnetic and paramagnetic. Most metals, including gold, silver and aluminum, are nonmagnetic.
Sinter plants agglomerate iron ore fines (dust) with other fine materials at high temperature, to create a product that can be used in a blast furnace. The final product, a sinter, is a small, irregular nodule of iron mixed with small amounts of other minerals. The process, called sintering, causes the constituent materials to fuse to make a single porous mass with little change in the chemical properties of the ingredients. The purpose of sinter are to be used converting iron into steel.
Sensor-based sorting, is an umbrella term for all applications in which particles are detected using a sensor technique and rejected by an amplified mechanical, hydraulic or pneumatic process.
A scrap metal shredder, also sometimes referred to as a metal scrap shredder, is a machine used for reducing the size of scrap metal. Scrap metal shredders come in many different variations and sizes.
Sunset Park Material Recovery Facility is a recycling facility at the South Brooklyn Marine Terminal in the Sunset Park neighborhood of Brooklyn, New York, United States. Operated by Sims Municipal Recycling, it was designed by Annabelle Selldorf, and its construction involved the use of a variety of recycled materials. The campus contains several structures, including an education center and New York City's first commercial-scale wind turbine. As of January 2022, it is the largest commingled recycling facility in the United States and the primary recycling center in New York City.
The scientific production association ERGA is Russia's largest manufacturer of magnetic systems and industrial equipment based on them. Production and the central office are located in Kaluga. The key activity is the development and production of equipment for mineral processing, air-gravity separation, integrated solutions for the processing of various wastes and the separation of materials according to electrical properties.
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