Scrap metal is a mixture of a metallic material or waste metal. It also includes that entire metal product that can be recycled for further use. (1)
Scrap metals are also termed used metals, which are a significant source of industrial alloys and metals, specifically in the production of copper, steel, lead, zinc, and aluminum. Smaller amounts of some precious metal such as magnesium, tin, or nickel are also recycled from scrap. Scrap metals have outstanding monetary value whether these are building supplies, vehicle parts, or surplus project materials. The metal recycling industry of the UK is now worth £5.6 billion.
Most of the scrap metals come from commercial and residential use. Impurities in organic materials such as wood, paint, fabric, and plastic can be burned off. Metallic impurities can be inert, desirable, or undesirable. Undesirable metals are either used in small proportions with pure metals or eliminated by refining. Ferrous or non-ferrous scrap metals can be re-used due to their high market value. The most valuable ones are non-ferrous scrap metals, and among them, more common are nickel, lead, tin, magnesium, zinc, aluminum, brass, and copper.
The most significant non-ferrous scrap metals
It is easily found on plumbing fixtures, keys, light fittings, and door handles. It is the most common and highly in-demand scrap metal. Its color is yellow with a little hue of red. Brass is a hybrid of copper and zinc, which are highly dense.
Aluminum is another most common scrap metal found in several places. It can be recycled to use again in some other ways. Empty food and drink cans are the common sources of aluminum. Some other good places to look for this metal are window frames, external and internal doors, siding, and guttering.
Copper is another metal that is commonly seen in home structures. In scrap yards, it is highly valuable metal to recycle. In a good condition, copper is reddish. But more worn-out fittings and fixtures come in dark brown or sometimes green. Being a versatile metal, it is used as a roofing material, plumbing pipes, and more.
Where to take scrap metal? (2)
Scrap metals are taken to recycling industries, where they get recycled for their further use. The process of metal recycling is the same as other recycling processes. The metals are separated according to their properties. For this purpose, the collector must have knowledge or understanding of metals. This aids in the recycling of metals and the maintenance of a green environment. The steps of the recycling process are as follows.
It is the first and most significant phase in the process of metal recycling. It involves the collection of all materials that contain metals. The process should be composed and must have containers for metals collection. Some business persons and people have created scrap yards. This encourages people to collect metals rather than discard them. They get paid for metals they have collected in the scrap yard. These yards are also termed collecting centers for scrap metals.
After the collection of scrap metals, the next significant phase is the sorting of metals. This involves the separation of non-recyclable metals from recyclable metals. It is essential to identify the quality of recycled metals. The high-quality original materials would yield recycled products of high quality. Therefore, strictness is required while checking the quality of material while sorting. According to a general rule, 50% metal must be present in the product. It is worth recycling, even if it is mixed with some other material but has metal in more proportion. Moreover, metal can be extracted from the material having metal in less proportion. Metals can be ferrous or non-ferrous. The way to identify them is using a magnet. The magnet will attract the ferrous-containing metal because it contains iron. Nowadays, x-ray and infra-red scanning have become popular in the sorting of metals. Three famous categories of sensing processes are pyrometallurgy, hydrometallurgy, and biotechnology. These technologies improve the recovery rates of metal.
The next step to sorting is to squeeze or compact the metals. All the sorted metals are squashed and squeezed with the help of several machines.
After the breaking and crushing of metals, the process of shredding starts. In this step, metals are shredded into tiny sheets or pieces for further processing. The surface-to-volume ratio of these pieces is large and can be melted at low energy. Normally, aluminum and steel are converted into sheets and steel blocks respectively.
Large furnaces are used to melt scrap metal. Every furnace is specific to the type of metal. In this process, a considerable energy amount is used. However, the amount of energy used to melt recycled metal is less than the energy used to make new metal. The duration of melting depends upon the size of the furnace, heat degree, and volume of the metal in a furnace.
Melting is followed by the purification process. The purpose of the purification process is to ensure high-quality and impurity-free metals. Among several purification processes, electrolysis is one of them.
The process of purification is followed by solidification. For this purpose, a conveyer belt is used to take molten metal to a cooling chamber. This chamber cools down and solidifies the molten metal. At this stage, the raw metal is recycled into new solid metal for re-use. Certain chemicals are added to the metal to make up its properties and density.
The final product is then packed according to its shapes and sizes and then transported to different people and factories where it is required.
Prices of scrap metals
- Bare bright wire costs $3.90/lb
- Copper tubing costs $3.65/lb
- Roofing copper costs $3.35/lb
- Brass pipe costs $2/lb
- Bronze costs $2.50/lb
- Brass shells cost $1.90/lb
- Clean brass radiators cost $1.90/lb
- Aluminum coil costs $1.55/lb
- Copper yokes cost $0.50/lb
- Copper transformers cost $0.18-$0.32/lb
- Small electric motors cost $0.35/lb