Melting vs. Smelting

Main Difference

The main difference between the terms melting and smelting is that melting is the conversion of a solid substance into a liquid and smelting is the conversion of ore to its purest form.

Difference Between Melting and Smelting

Comparison Chart

Melting vs. Smelting

Melting is the process of converting or changing the state of a substance from solid to liquid form. Smelting is the process of extracting the metals from ores in the purest form. Melting is a simple process of heating the substance to its melting point where it starts to liquefy. Smelting is a process that involves heat and chemicals to melt the ore and convert it into pure metals. In melting, substances are put under great pressure to melt them, a combination of heat and pressure is also used. A body can be melted at a lower temperature as well. With the combination of heat and pressure, In smelting, chemicals such as reducing agents are used to wash out other elements from ores into slag (waste) or gases leaving just the metal behind. Melting is mainly done to mold an element or substance into a particular shape to use it in various ways. Smelting is done for basic metals like copper, iron, silver, and gold. In simple wording, melting is the process by which a substance changes from its solid phase to its liquid phase. Smelting is a process by which metal is extracted from its ore at temperatures beyond the melting point. Melting of a pure substance does occur at a fixed temperature called the melting point. Smelting involves a step known as roasting which is done at very high temperatures. So, melting occurs at the melting point of a (pure) substance and smelting is done at the temperatures beyond the melting point of an ore.

What is Melting?

Melting is a simple process of heating the substance to its melting point where it starts to liquefy. It is the process of converting or changing the state of a substance from solid to liquid form. In melting, substances are put under great pressure and heat to melt them. Melting is mainly done to mold an element or substance into a particular shape so to use it in various ways. Melting is also known as fusion. It is a process of phase transition. The internal energy of the substance increases During melting. In the process of melting, the tight packing of molecules or ions starts to loosen. A solid substance has a more well-ordered and tight structure than a liquid. Melting converts it to a less ordered structure. When a solid start to melt, its volume increases because the liquid has no tight packing like the solid. Therefore, the density is decreased. But there are some exceptions too like the melting of ice to form water. In this case, the density of ice cubes is lower than water. Melting point is a point of temperature where the solid starts changing its form into a liquid. The melting point of an impure substance is not fixed as it melts at a different temperature. The melting of an impure substance is varied depending on the type and the amount of the impurities present. In the process of melting a substance or an element, the viscosity also changes when it is in a liquid state.

What is Smelting?

Smelting is the process of extracting the metals from ores in the purest form. It involves heat and chemicals to melt the ore and convert it into pure metals. There are two requirements of the smelting process, heat treatment, and reducing agent. Smelting obtains a metal at temperatures beyond the melting point from its ore. An ore is a naturally occurring material in solid form, from which a metal or valuable mineral is extracted profitably. Smelting involves the conversion of ore into its purest form. The third process removes metal from the ore that is mined. Very strong heat is applied to separate the pure metal from other impurities. The common applications of smelting include the production of iron, silver, copper and other metals from their ores. The smelting process has two main steps which a roasting and reduction. Roasting involves heating the ore in the presence of a large amount of air or oxygen. Reduction involves the environment that removes the oxygen atoms from the raw material. Carbon is the most common reducing agent. The ores are mostly impure, so a cleaning agent like limestone is used to take the impurities out as waste to obtain the pure metal. Smelting is a very important and basic process to obtain the metals in their pure form.