Does Zinc Rust or Corrode?

Zinc is a metal. That means it must rust, right?

Zinc doesn’t rust, but it does corrode. Rust only occurs in metals that have iron in them, whereas corrosion can occur in many types of metal. Corrosion occurs when metal has a chemical reaction with elements in its environment, causing it to breakdown.

In the article below, you will learn more about zinc and why it doesn’t rust. You will also learn how zinc, through a process known as galvanization, protects other metals like iron and steel from rusting.

What Is Zinc?

Lead zinc ore texture.

Zinc, or Zn, is an element with an atomic number of 30. It is a blueish white transition metal that is the 24th most abundant element in the entire world!

It was first formally identified as an element in 1746. However, the Greeks and Romans knew about zinc before 20 BC.

India was the first country to smelt zinc in 1200 CE. They were able to do this by creating a specialized chamber that heated the zinc at the top and then cooled it at the bottom. This process allowed them to extract the zinc from its ore. If you want to see exactly how they did it, check out this informative video by The Art of Living.

Today, zinc is found in mines around the world. The most prominent zinc mining sites are in China, Australia, and Peru.

Zinc is a non-ferrous metal, meaning it does not contain any iron. Non-ferrous metals are known to be lightweight, have high conductivity, and are non-magnetic. These qualities are highly desirable for manufacturers. Thus, non-ferrous metals are used to make a lot of products!

Next, we will take a closer look at zinc’s physical properties to determine why it doesn’t rust, and what it does instead. 

Does Zinc Rust?

Zinc does not rust, but it does corrode. You may be wondering, what’s the difference?

Well, rust is a term that only applies to metals that have iron in them. Rust occurs when oxygen interacts with iron in the presence of water or moisture, causing it to oxidize. During the process of oxidation, iron loses electrons and forms iron oxide, which is the reddish-brown substance you know as rust.

Corrosion, on the other hand, happens to a variety of metals, including those without iron in them. Corrosion occurs when metals have a chemical reaction with elements in their environment, causing them to breakdown.

Some things that cause metals to corrode are water, acids, bases, salts, and oils. Metals can also corrode when they are exposed to gases, such as acid vapors, formaldehyde gas, ammonia gas, and gases that have sulfur in them.

Zinc corrodes when it is exposed to air and water, but it corrodes very slowly. It is often used as a protector for metals that erode very quickly, such as iron and steel.

Zinc Protects Iron & Steel From Rusting

Zinc galvanized metal fence.

Because zinc corrodes very slowly, it is used to protect iron and steel from rusting via galvanization. Galvanization is the process of coating iron or steel in zinc. Galvanizing iron or steel with zinc protects it in two different ways:

  • Zinc reacts with moisture and CO2 in the air, which causes it to form a film. This film prevents oxygen and moisture from getting to the iron or steel below.
  • Zinc is more reactive than iron and steel, so it oxidizes (loses electrons during a chemical reaction) instead of the iron or steel. Typically when iron and steel oxidize, they rust. So zinc acts as a “sacrificial metal” to prevent the iron and steel from rusting.

In the video below MEL Science shows you just how effective zinc is at protecting iron from deterioration!

In the experiment, they have two cups filled with water. Next, they add iron to one cup, and iron and zinc to the other cup. They then let the cups sit for 40 minutes.

After 40 minutes, the cup containing the zinc and iron has clear water, while the cup containing only iron has water with a reddish tint, indicating that iron particles started to dissolve into the water!

This simple experiment demonstrates how zinc protects iron from rusting.

How to Galvanize Steel and Iron?

The most common type of galvanization is hot-dip galvanization. To do this, you dip steel into a molten bath of zinc, which is around 840 °F (449 °C). That’s one hot bath!

Another method of galvanization is electrogalvanization. During this process, zinc is bonded to steel through electroplating. Electroplating is when you run an electric current through metal, such as zinc, to dissolve it onto another surface.

Both of these methods of galvanization are especially effective for stopping corrosion because they allow the zinc to form an outer protective layer, called the zinc patina.

When the outer layer of zinc is exposed to the environment and begins to corrode, it reacts and forms a protective layer of zinc oxide. The zinc oxide layer is water-resistant and helps slow down the corrosion process.

Galvanization is used to make a variety of products, including the steel framing in buildings, gutters, street lamp posts, suspension bridges, the bodies of cars, phone wiring and equipment boxes, and more! 

What Is Zinc Used For?

Zinc is the fourth most commonly used metal in the world, behind iron, aluminum, and copper. Many people use zinc in their daily lives, but they may not even realize it. Listed below are some common uses of zinc that might not have heard of!

  • Zinc eye medication has been used since ancient times and is still in use today. It helps alleviate redness, dryness, and burning of the eyes. 
  • Zinc dandruff shampoo is great for treating a flaky scalp, due to zinc’s antibacterial properties. Check out this awesome Solimo Dandruff Shampoo on Amazon to stop your scalp from itching once and for all!
  • Zinc body wash is also good for your skin because of zinc’s antibacterial effects. Zinc is especially good for people with eczema, and may even help those with acne. If you want a nice zinc body wash to help soothe your skin, try DermaHarmony 2% Pyrithione Zinc Bar Soap.
  • Zinc sunscreen is an amazing product because zinc scatters the sun’s rays, preventing ultraviolet radiation from getting to your skin. If you want to keep your face protected from the sun while also getting the benefits of zinc’s UV fighting powers, check out this Neutrogena Sheer Zinc Face Sunscreen.
  • Zinc is found within our bodies. We use it to fight off invading bacteria and viruses. Without it, we can suffer terrible health problems. If you want to boost your immune system, check out these Best Naturals Zinc Citrate Tablets.
  • Zinc Die Casting is a process in which molten metal is poured into steel molds. This process is used by manufacturers all over the world to make mechanical parts, such as gears, pinions, automobile components, and more. Zinc is strong and durable, making it the perfect element to make all kinds of parts.
  • Zinc oxide, which is a combination of zinc with oxygen, is used to make a variety of products, including paints, plastics, ceramics, glass, cement, batteries, rubber, electrical equipment, and more!

Zinc is a very important element. It is used for a wide variety of manufacturing projects, and it is used by our bodies to keep us healthy.

Conclusion

Zinc is a non-ferrous metal that is used to make a variety of products. While zinc does not rust, it does corrode over time. Zinc’s corrosive properties are one of its most important features since this allows it to protect other metals, such as iron and steel, from rust and corrosion. Zinc does this through a process known as galvanization, which is used in a variety of production processes.

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