Concentration of Ores

The procedure of ore concentration is a critical stage in obtaining a pure metal from its ore. 

An ore contains several contaminants, including sand, grit, and pebbles. We collectively refer to these contaminants as “Gangue.” Separating the ore from the gangue particles is required for metal extraction. 

One of the most significant phases in extracting metal from its ore is the concentration of ore, also known as ore enrichment, ore-dressing, and benefaction. It is a technique for removing gangue particles and other contaminants. 

Let us discuss this topic in detail.

What is an Ore?

An ore is an economically valuable mineral concentration. Based on the minerals and components involved, the richness of ores might vary greatly. Chromium ore is mostly made up of the mineral chromite, which contains chromium as a primary component. Although magnetite is the most common vanadium ore, vanadium is only a tiny component of that material. Only traces of platinum-rich minerals may be found in platinum ore, and many of them are so little that they can’t be seen with the human eye.

Ores go through a physical improvement process before being processed with chemical procedures to recover metals. Crushing and grinding are used to release minerals, which are then separated using physical methods such as gravity, magnetic separation, and other physicochemical approaches.

What is Concentration of Ores?

As we all know, minerals could be found in ores. We should first dig the mineral’s ore to extract it. When extracting the metal from an ore, it is important to eliminate the impurities. Impurities, or unwanted elements, can be found in minerals. The ore contains different undesirable impurities including sand, abrasive minerals, and so forth after it has been mined from the earth. Unwanted contaminants such as earthy materials, rocks, sandy materials, limestone, and so forth are referred to as gangue.

Methods of Concentration of Ore

The following are the many methods for the concentration of ores;

Hand-picking

It is an old method of merely concentrating ore with one’s hands. In this procedure, a hammer is used to separate the gangue and adherent solid matrix from the ore. The separation and identification of gangue are based on colour variations in the solid state.

Hydraulic Washing

Hydraulic washing is the difference in gravity of the gangue with ore particles. As a result, it is classified as a gravity separation method. The powdered ore is washed with an upward stream of flowing water throughout this procedure. The heavier ore particles are left after the lighter gangue particles have been washed away. Because tin and lead ores were heavier than the gangue, hydraulic washing is utilized.

Ore Concentrated by Froth Flotation Process

The gangue is separated from the sulfide ores using this process. Cu, Pb, and Zn sulfide ores are processed using this method. 

The froth flotation method is used to concentrate sulfide ores. The process concentrates just sulfide ores since pine oil preferentially wets the sulfide ore, causing it to froth.

The froth is minimal and easily removed. The ore particles are therefore dried for recovery. Depressants are often used to extract sulfide ores by altering the oil-to-water ratio, such as a zinc sulfide plus lead sulfide ore. Sodium cyanide is often used as a depressant.

Magnetic Separation Method for Concentration of Ore

To divide the ore and gangue, magnetic characteristics of either the ore or the gangue are used. The ore is first finely processed before being conveyed on a conveyor belt that passes past a magnetic roller. The magnetic ore stays on the belt, while the gangue slides off.

Conclusion

Ores are solid materials that can be used to produce pure metals. Concentration, dressing, or benefaction of ores is extracting undesirable particles from ore. There are various steps to it. The variations in physical characteristics of the existing metal complex and that of the gangue are used to separate the needed material from the ore.