Concentration of Ore

Introduction

Minerals are present in ore in complexes with other components. The extraction of a metal refers to the process of extracting metal out of its ores. Metallurgy is the study of the processes of obtaining metals from their ores and purifying them. There is no single method for removing all of the metals. Different methods must be utilized depending on the metal. Ore concentration, also referred to as enrichment of ore, is among the most crucial stages in the extraction of metal out of its ore.

What do you understand about the concentration of Ores?

As we all know, minerals can be present in ores. To harvest the mineral's ore, we must first pull it up. Contaminants must be removed from an ore before the metal can be recovered. Impurities, or unwanted elements, can be found in minerals. The ore includes different undesirable contaminants such as sand, abrasive minerals, and so on after it has been mined from the earth. Unwanted contaminants like rocks and limestone along with sandy materials are referred to as gangue.

To remove these undesired compounds, the ores are concentrated according to the type of contaminants and their proportion. We may be able to obtain a concentrated ore with a high metal content by eliminating these contaminants. The elimination of gangue particles from ore, also known as ore concentration, is added to enhance the quantity of metal inside the ore.

What is Ore?

Ore is a concentration of more than one precious mineral found Beneath the earth. Metals such as Cu along with Fe, which are present in the ore deposits with the highest value, are crucial to industry and trade. Metal can be collected from ore utilising a wide range of processes such as ore concentration, metal refining along with mental isolation. Ores contain minerals that can be used to recover metals efficiently and profitably.

Types of Ore

Magmatic or volcanic ore

Some ores are formed when minerals cool and crystallise within igneous intrusions/ magmas/lavas. Magmatic or volcanic ores are what they're called. Nickel, iron along with copper ores are commonly found in volcanic or magmatic deposits.

Carbonate alkaline ore

In Addition to volcanic as well as activity, other igneous processes produce carbonate alkaline ores. Rare earth elements as well as some diamonds belong to the carbonate alkaline group. As one might expect, if ores are produced as a consequence of igneous events, sedimentary/metamorphic occurrences can also occur.

Sedimentary ore

Banded iron formations, gold, tin, platinum, zinc as well as even diamond-containing ores generated in sedimentary environments are examples of deposits of sedimentary ore.

Hydrothermal ore

Finally, hydrothermal reactions can result in the formation of ores. Rocks & minerals are exposed to incredibly hot water in these processes, which are found in the vicinity of vents of oceanic hydrothermal processes/hot springs. The majority of ores of uranium, as well as gold, were created by hydrothermal processes.

Methods of the Concentration of Ore

Hydraulic Washing

The smaller particles of gangue are removed from the bulkier metal ore when the ore is passed through an upstream stream of water.

This technique is used to enhance ores that have a higher density than the particles of gangue contained. A jet of water is passed through broken and ground into powder ore in this procedure. The lighter gangue particles are washed away by water, leaving the bigger ore particles behind. Ores of Tin, as well as Lead oxide, are concentrated using this method.

Froth Floatation Process

This method is used to separate gangue from ores of sulphide. To make a suspension, the ore is pulverised and combined with water. Fatty acids and Pine oils along with other collectors increase the metal component of the ore's non-wettability, allowing it to form a froth. The foam is kept flowing by cresols, aniline, and other froth stabilisers. The oil lubricates the metal, whereas the water lubricates the gangue. The froth is created by continually stirring up the suspension with paddles and air. To keep the metal, the frothy metal is skimmed off the top and dried.

John Atherton, Froth flotation device used in archaeological excavations at a prehistoric American Indian site in north-Central Oregon (USA) near the Hancock Field Station, 1977 (2301765127), CC BY-SA 2.0

Physical Methods and Chemical Methods

Physical methods

• Hand-picking − It was the old way of refining ore directly with the hands. The gangue or adhering solid matrix is scraped from the ore using a hammer in this method.

• Magnetic separation − Focusing on the magnetic characteristics of either ore or matrix, the magnetic separation method separates ore from gangue particles. The ore is coarsely crushed & passed over two magnetic rollers, one of which is magnetic as well as the other non-magnetic, in this procedure. With the use of a hammer, a solid matrix is removed from the ore.

Chemical methods

• Roasting − Under the influence of heat & air, it is a method that is commonly used for Sulphide ores.

• Leaching − It's a chemical method that entails reacting the ore with the right reagent to make it soluble.

  $$\mathrm{ Al_2 O_3 + NaOH\rightarrow 2NaAlO_2 + H_2 O }$$

  It is feasible to separate the soluble ore/mineral from insoluble gangue.

Conclusion

It can be concluded that ore is a type of rock that has a big enough proportion of a certain mineral (typically a metal) to make its extraction from the surrounding rock commercially viable. Ore convent ratio also referred to as enrichment of ore, is among the most crucial stages in the extraction of metal out of its ore. Not all minerals are present in large enough numbers in one place to make mining the ore from the rock profitable. If there's enough of it, the rock will be removed and treated in a variety of methods to separate the mineral from the rest of the rock.

FAQs

1. What technique is used to concentrate sulphide ore in metallurgy?

The froth flotation method is used to extract Sulphide ores. The approach is based on the preferred wetting properties of the foaming agent with water.

2. Which of the following is a gravity-based ore concentration method?

Gravity separation, commonly known as hydraulic washing, is a separation method that separates metallic ore with gangue particles based on specific gravity differences.

3. Is diamond a mineral or an ore?

The only stable source of diamonds is diamond ore, which is a rare metal that forms deep down.

4. What are the applications of ores?

The majority of the world's gold ore is being used to make jewellery and ornaments. A deposit of one or more valuable minerals in the Crust of the earth is known as ore. Cu as well as Fe, two key metals for industry and trade, are found in the most precious ore resources. Cu ore is mined for use in a variety of industries.

5. When it comes to minerals and ores, what's the difference?

Minerals are inorganic substances with a crystalline form and a certain chemical formula range that exist naturally. Mineral quantities in rock that are large enough to be economically removed are referred to as ore.