Methods and equipment for recycling, metal recycling

Iron ore reserves are depleting, but demand for ferrous metal products remains stably high. The problem of the lack of raw materials for the production of cars, wagons, steel structures can be solved in one way. This way is scrap cars in vaughan.

Who accepts scrap metal?
In all cities and district centers there are points of acceptance of metal waste. Large items, such as railroad cars, are accepted by specialized points located in cities. It is compulsory for each receiving facility to be licensed. An additional license is required to accept medical equipment.

When taking heterogeneous scrap metal, it is more profitable to sort it yourself. If you dispose of large parts mixed with metal shavings, the scrap metal will be accepted at the price of the cheapest category.

It is advisable to remove the seats, dashboard, and plastic elements from the car. If you do not do this, the collection point employee will deduct the weight of the non-metal parts from the weight of the car and the cost of dismantling work from the scrap fee.

Disposing of ships is a problem: it is much more difficult to dismantle them than a car. It requires a lot of work by trained people, and the purchase or rental of special equipment. Dismantling costs can exceed the value of recyclable materials. Lately ships have been ending up in the poorest countries with cheap labor.

How is ferrous metal recycling done?
Scrap metal is not taken immediately to a shop to produce new products. It first goes through several stages of preparation. Scrap metal recycling includes shredding the metal waste by one of the methods, sorting, cleaning. Pressing or casting into ingots completes the procedure of turning scrap into secondary raw material.

Thermal Shredding
Large pieces of scrap metal are first shredded. Thermal shredding is the separation of long or sheet elements into pieces by local melting. Oxygen or plasma cutting, oxygen lance boring, and other thermal shredding methods are used.

Explosive and coproductive shredding
Pieces of scrap metal from 1.5-2 tons are difficult and sometimes impossible to shred by thermal or mechanical cutting. They are shredded by blasting. Scrap metal and explosives are placed in an armored pit. A sturdy cover with a hole for the charge protects the surrounding area. The shock wave of the explosion crushes the metal into pieces suitable for further shredding by other means. Metal structures are detonated by placing the explosive point by point in several places.

The metal crushed by the explosion is crushed by a coping method. Scrap metal is placed on a platform with a solid foundation and thick walls, with a rail trestle running above it. A coke drum, weighing up to 15 tons, is dumped on the scrap to be crushed. The cranes of the upper tier of the trestle lift the hog and collect the broken metal from the second tier with a magnet.

Diverse metal scrap takes up a lot of space, it is difficult to store, load and transport. The solution to this problem is metal baling, which is the pressing of scrap metal in machines that compress it in three dimensions. Piles of sheet metal, stamping, wire, and household scrap are turned into neat billets. They can be folded compactly to cover them from the rain.

Mechanical Cutting
Metal waste is shredded mechanically with gantry and alligator shears. Plate iron up to 2 cm thick is cut with portal or hydraulic shears, while alligator shears cut pipes and rebar. Also used are bolt cutters, friction saws, band saws.

Shavings crushing
The chips from the recycling process are either recycled or crushed. Rotary mills, roller mills, hammer mills and shredders are used for the crushing process. The output is metal crumbs of a given size.

Sorting of metal
Scrap metal is sorted according to a number of indicators. The sorting of the waste into categories takes place on the conveyors and sorting tables. Special devices assess the chemical composition of the waste and the amount of impurities, which allows to separate the metal by steel and iron grade. Material characteristics, GOST specifications, radiation, spectral and other analyses are taken into account during sorting.

Cleaning process
There are impurities of non-metallic substances on scrap metal: dust, dirt, paint, residues of fuel and lubricants.

At the collection points, scrap metal is cleaned in the following ways:
Processing with a powerful air stream. After this treatment no foreign substances are left on the surface of the metal.

Magnetic separation. After crushing, scrap is cleaned with a magnet of adjustable power. Separators can be drum-type or flat-type. Foreign impurities remain unattracted by the magnet.
Small collection points can not buy a complete set of equipment, so they use a manual method of cleaning.
Oils and emulsions are cleaned from debris by processing in a centrifuge.
Melting and Preparation
After cleaning, the scrap metal is sent for remelting. Large pieces are cut into strips for easy immersion in the furnace, and thin scrap elements are briquetted.

Processing at the smelter
Briquettes and strips of scrap metal are remelted in electric and plasma furnaces. Electric furnaces have higher efficiency and safety, plasma furnaces are cheaper.

Scrap is piled in a ladle of steel with an elevated melting point. Molten iron is poured on top and blown with oxygen. At this stage, the steel is freed from excess sulfur, phosphorus and other unwanted impurities that increase the brittleness of the products.

Then additives are added to the molten metal to give the steel the desired properties: resistance to corrosion, increased strength, etc. Cobalt, nickel, chromium, and vanadium are used as additives.

Large refineries carry out not only smelting, but also rolling of the metal. Such companies are more profitable.

What types of scrap metal cannot be recycled?
Metal is not always recyclable. Rusted scrap metal is not suitable for remelting. A moderate amount of rust is acceptable, but individual collection point rules may prohibit acceptance of such items.

All scrap metal must be monitored for radiation. If the dosimeter shows radiation that is close to the maximum permissible limits, recycling of such metal is possible after additional cleaning. Scrap metal that exceeds the limits of the radiation background is to be buried.

High radiation levels are characteristic of nuclear icebreakers, submarines, nuclear power plant equipment, icebreakers, and submarines. Scrap metal that has been stored for a long time in conditions of high radiation, as well as some types of medical equipment, is thoroughly checked.


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