What causes metals to corrode?

Ever seen those dreary red vehicular bridges or metal structures leading to water tanks, creaky gates, fences or handles? The most common example of corrosion that we see in our everyday lives is rust – corrosion of the iron metal. This redness indeed is a typical representation of the phenomenon of ‘corrosion of metals’. Corrosion is when the metal quality has deteriorated.

What causes corrosion of metals?

Corrosion in metals is an electrochemical process; it is part chemical and part electrical. Positively & negatively charged ions from the metal result into a chemical called ‘iron hydroxide’ when they come in contact with water. When both oxygen and moisture work their wrath on the metal, it causes the metal to corrode. It will continue to cause the reaction leaving back nothing but say, a pile of rust (in case of iron) as long as the process continues.

Which metals are prone to corrosion?

In the metal family, magnesium, aluminum, iron, zinc, brass, copper, bronze and tin have higher reactivity so they easily corrode. Rust on steel, greening of copper or tarnish on silver/brass is a common phenomenon that we see every day around us. It also represents danger to human lives as its impact can cause injury.

What are the typical causes of corrosion?

·         Improperly maintained metal

·         Use of low quality metal

·         Ignorance towards maintenance of structural issues such as plumbing problems, leaky areas/roofs, stagnant water, and foundation issues of the building/structure, etc.

Does this mean all metals corrode? No, some metals rarely corrode. This group of metals which are less reactive, also known as ‘Noble Metals’ are metals that can be found in nature in their purest form - rhodium, palladium, silver, platinum, and gold are some examples of metals that are much less reactive than others; thus more expensive!

Understanding of the environmental conditions and metal properties and implementing this understanding into your design structure or foundation is an effective preventive measure against metal corrosion.

How is Scrap Metal Processed

In an era of recycling, it is imperative to have knowledge of recycling process in order to take better decisions of the tools and methods of recycling. The recycling process dealt with here in particular, is scrap metal. 

A scrap metal processing yard where one gives away his or her scrap metal for recycling, chiefly categorize the metals into ferrous and non-ferrous metals. Ferrous (from Latin ferrum, meaning "iron") metals comprised of iron and steel (an iron alloy). Copper, aluminium, brass et al., are called non-ferrous metals.

Scrap metal processing in part entails separation of these types of metals from each other using magnetized tools. A number of wrecking yards allow people to purchase scrap metals for specific purposes. Such a sale occurs only after due separation of the metals. This makes for easier identification of the metal by an interested buyer.

The primary basis of the sale of metals by the wrecking yards is the weight of the scrap metal being sold. Quality of the metal is really not that important in such a scenario. This is because the main concern of the yards is what the metalworks factories give them for selling metal. Metalworks factories purchase metals on the basis of weight.

After proper separation and sorting into suitable divisions, the scrap metal is subject to a number of processes which include cutting, shredding, molding and turn into metal cubes. The metal cubes are then purchased by the metalworks factories that melt the metals for the manufacture of new products.