question: Where does rusted/used metals go after we remove it. Like old train tracks or old broken fences
comment: Mostly to scrapyards. While scrap is synonymous to garbage for most people, scrap at the scrapyard will be separated into the various kinds of metals it consists of and then be sold to smelters for further refinement or to steel mills for the production of new steel products.
passages: Due to their extensive use, non-ferrous scrap metals are usually recycled. The secondary materials in scrap are vital to the metallurgy industry, as the production of new metals often needs them. Some recycling facilities re-smelt and recast non-ferrous materials; the dross is collected and stored onsite while the metal fumes are filtered and collected. Non-ferrous scrap metals are sourced from industrial scrap materials, particle emissions and obsolete technology (for example, copper cables) scrap.
  
  Section::::Ancient history.
   BULLET::::- Bronze sculptures: For many bronze sculptures and other metal sculptures, treatment includes a reduction buildup from previous protective coatings, removal of corrosion and incrustation, or cleaning. This may be done by hand, water blasting, air abrasion, or other methods. Then, a wax or wax composite is applied to the sculpture in sweeping motions. Finally, the wax is buffed with a cotton cloth.
   Iron and steel are the world's most recycled materials, and among the easiest materials to reprocess, as they can be separated magnetically from the waste stream. Recycling is via a steelworks: scrap is either remelted in an electric arc furnace (90-100% scrap), or used as part of the charge in a Basic Oxygen Furnace (around 25% scrap). Any grade of steel can be recycled to top quality new metal, with no 'downgrading' from prime to lower quality materials as steel is recycled repeatedly. 42% of crude steel produced is recycled material.
  
  Section::::Metals.:Other metals.
  
  For information about recycling other, less common metals, refer to:
   Section::::Divisions.
  
  Section::::Divisions.:Metals Recycling.
  
  Sims Metal Management buys ferrous metal from metal dealers, peddlers, auto wreckers, demolition firms and others who generate obsolete metal and from manufacturers who generate industrial metal. Ferrous metal is processed for resale using a variety of methods, including sorting, shredding, cutting, torching, baling or breaking. After processing, ferrous recycled metal is sold to end users such as EAF mills, integrated steel mill, foundaires and brokers.
   During the summer of 2009, MT2 performed a lead remediation job at the North Las Vegas Police Department Firing Range An estimated 100,000 pounds of metal was removed from the berm used to catch the bullets over the previous 30 years (roughly 2 million bullets). Prior to the work, officers were actually getting hit by ricocheting bullets.
  
  Section::::Recent clients.:Henry Horton State Park.
   Section::::Deterioration of materials associated with metals.
  
  Associated materials deteriorate depending on the origin whether they are organic or inorganic materials. Organic materials usually fail in a relatively short period of time, primarily due to biodegradation. With inorganic materials are these processes considerably longer and more complex. Amount of gases, humidity, depth and composition of soil are very important. In case of salty and sweet water finds essential are amount of gases dissolved in water, depth of water, direction of currents, and microscopic and macroscopic living organisms.
  
  Section::::Deterioration of materials associated with metals.:Organic materials.
  
  BULLET::::- Leather
  
  BULLET::::- Wood
  
  BULLET::::- Paper
   Sims sources non-ferrous metals from manufacturers, known as production offcuts, and from generators of electricity, telecommunication service providers and others who generate obsolete metal. Peddlers and metal dealers, who collect from a variety of sources, also deliver material directly to their facilities. In addition, the company generates significant quantities of non-ferrous metal as a byproduct.
   BULLET::::- Welding - oxyacetilene / electric arc / TIG / tack / laser / plasma
  
  BULLET::::- Gluing/Cementing
  
  BULLET::::- Reconstructions -in original material - in polymers - *3D printing
  
  Section::::Conservation.:Interventive conservation.:Reconstruction of missing parts or surface decoration.
  
  In certain cases, metals conservator must re-create the lost parts of objects or restore original surface decoration. This approach is accurate only if we have an exact documentation or photographs of items in a complete, currently non-existent state that we want to return.
  
  New parts must be clearly and visibly marked and at least they must be minimally different from the original historic material.
   The most common procedure in conservation and restoration of metals is the cleaning process. This process can be distinguish between mechanical, chemical, electrochemical, ultrasonic, plasma and laser cleaning. In principle, it is aimed at removing dirt and corrosion products from the surface of a metal object. In many cases archaeology objects only can be cleaned mechanically.
  
  Section::::Conservation.:Interventive conservation.:Structural consolidation.
  
  Aimed at strengthening of the physical structure of the object, and correcting the shape of the object.
  
  BULLET::::- Mechanical joining - riveting / tab and slot / overlapping / screws
  
  BULLET::::- Soldering - soft / hard
   Decontamination for toxic metals is different from organic toxins: because toxic metals are elements, they cannot be destroyed. Toxic metals may be made insoluble or collected, possibly by the aid of chelating agents, or through bioremediation. Alternatively, they can be diluted into a sufficiently large reservoir, such as the sea, because immediate toxicity is a function of concentration rather than amount.
   Section::::Contemporary conservation methods.:Cleaning and removal of corrosion and incrustation.:By hand.
  
  One method of removing particularly tough incrustations off of a sculpture is by mechanical cleaning done by an individual. Such methods could include heating or potentially applying a solvent to a specific location to weaken the incrustation, followed by removal with a scalpel, spatula, or other such device.
   Depending on the sculpture or object, delicate work could be done under magnification with a low-heat light. Some tools used in this scenario are: “glass-fiber brushes, painting brushes, dental picks, a pin held in a pin vice, wooden carving tools or sticks, and small camera bellows to blow away dust.”
  
  Section::::Contemporary conservation methods.:Cleaning and removal of corrosion and incrustation.:Water blasting.
   Toxic materials including many organic materials, metals (such as zinc, silver, cadmium, thallium, etc.) acids, alkalis, non-metallic elements (such as arsenic or selenium) are generally resistant to biological processes unless very dilute. Metals can often be precipitated out by changing the pH or by treatment with other chemicals. Many, however, are resistant to treatment or mitigation and may require concentration followed by landfilling or recycling. Dissolved organics can be "incinerated" within the wastewater by the advanced oxidation process.
  
  Section::::Treatment of industrial wastewater.:Removal of toxic materials.:Smart capsules.
   When galvanised feedstock is fed to an electric arc furnace, the zinc is recovered from the dust by a number of processes, predominately the Waelz process (90% as of 2014).
  
  Section::::Production.:Environmental impact.
   Section::::Metals conservation planning.:Documentation.
  
  Systematic and well-managed documentation is today an essential prerequisite for quality executed conservation and restoration treatments, including documentation of the state of objects before, during and after treatment. Identification of materials and procedures used to produce object and the results of any scientific research must be part of documentation too. Last but not least- an integral part of the documentation must be a recommendation for further care of object.
  
  Section::::Metals conservation planning.:Ethics and ethical problems in metals conservation.
   Section::::Treatment.
  
  Section::::Treatment.:Treatment Considerations.
   BULLET::::- Aqueous cleaning
  
  BULLET::::- H2O - Deionized, Reverse Osmosis, or Distilled
  
  BULLET::::- Detergents
  
  BULLET::::- Chemical cleaning
  
  BULLET::::- Sodium Bicarbonate
  
  BULLET::::- Flitz Paste Polish
  
  BULLET::::- Maas
  
  BULLET::::- Mineral Spirits
  
  BULLET::::- Solvents
  
  BULLET::::- Ultrasonic
  
  Painted objects
  
  Painted objects can be cleaned with polar solvents (acetone, ethanol) and non polar solvents (hexanes and toluene) or solvent mixtures (xylene ). When working with solvents a conservator will use best practices in health and safety. The use of personal protection equipment is recommended.
  
  Structural consolidation
   Unsealed plaster can be cleaned with soft brush only; never try to use water or water-based cleaning solutions. Sealed plaster can be cleaned with a swab dampened with water or white spirit.
  
  Section::::Replicas and Copies.
  
  BULLET::::- molding (process)
  
  BULLET::::- casting
  
  BULLET::::- electroforming
  
  BULLET::::- 3D printing
  
  Section::::Storage of metallic heritage objects.
   An essential cause of deterioration is corrosion of metal objects or object deterioration by interaction with the environment. As the most influential factors of deterioration of historical objects should be pointed out as the relative humidity and air pollution while in archaeological objects a crucial role has composition, depth, humidity and amount of gasses in the soil. In cases of marine or fresh water finds the most important factors of decay are the amount and composition of soluble salts, water depth, amount of dissolved gases, the direction of water currents and the role of both microscopic and macroscopic living organisms.
   BULLET::::10. Development and Testing of Organic Coatings for the Protection of Outdoor Bronze Sculpture from Air-Pollutant Enhanced Corrosion – Year (2001-09)
  
  BULLET::::11. Development and Testing of Organic Coatings for the Protection of Outdoor Bronze Sculpture from Air-Pollutant Enhanced Corrosion – Year 2 (2001-08)
  
  BULLET::::12. Development and Testing of Organic Coatings for the Preservation of Outdoor Bronze Sculpture from Air-Pollutant Enhanced Corrosion – Year 3 (2002-18)
  
  BULLET::::13. Development and Evaluation of Removable Protective Coatings on Bronze (2004-27)
  
  BULLET::::14. Research Into Protective Coating Systems for Outdoor Bronze Sculpture and Ornamentation Phase I (1997-03)
   Section::::Identification Processes and Analysis.
   Ferrous metals are able to be recycled, with steel being one of the most recycled materials in the world. Ferrous metals contain an appreciable percentage of iron and the addition of carbon and other substances creates steel.
  
  Section::::Ferrous metal recycling.:Description.
   A wide range of metals in commercial and domestic use have well developed recycling markets in most developed countries. Domestic recycling is commonly available for Iron and steel, aluminium and in particular beverage and food cans. In addition, building metals such as copper, zinc and lead are readily recyclable through specialised companies. In the UK, these are usually either specialised scrap dealers or car breakers. Other metals present in smaller quantities in the domestic waste stream such as tin and chromium are also extracted from metal put into the recycling system but are rarely recovered from the general waste stream.
   Rust removal from small iron or steel objects by electrolysis can be done in a home workshop using simple materials such as a plastic bucket, tap water, lengths of rebar, washing soda, baling wire, and a battery charger.
  
  Rust may be treated with commercial products known as rust converter which contain tannic acid or phosphoric acid which combines with rust; removed with organic acids like citric acid and vinegar or the stronger hydrochloric acid; or removed with chelating agents as in some commercial formulations or even a solution of molasses.
  
  Section::::Economic effect.
   Impurities are mostly arsenic, antimony, bismuth, zinc, copper, silver, and gold. Typically they are removed in a series of pyrometallurgical processes. The melt is treated in a reverberatory furnace with air, steam, and sulfur, which oxidizes the impurities except for silver, gold, and bismuth. Oxidized contaminants float to the top of the melt and are skimmed off. Metallic silver and gold are removed and recovered economically by means of the Parkes process, in which zinc is added to lead. Zinc, which is immiscible in lead, dissolves the silver and gold. The zinc solution can be separated from the lead, and the silver and gold retrieved. De-silvered lead is freed of bismuth by the Betterton–Kroll process, treating it with metallic calcium and magnesium. The resulting bismuth dross can be skimmed off.
  