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Jai Ganesh

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Metallurgy

Metallurgy

Gist

Metallurgy is defined as a process that is used for the extraction of metals in their pure form. The compounds of metals mixed with soil, limestone, sand, and rocks are known as minerals. Metals are commercially extracted from minerals at low cost and minimum effort.

The title of "father of metallurgy" is often given to Georgius Agricola (1494-1555), a German scholar and scientist. He is recognized for his groundbreaking work, particularly his book "De re metallica" (1556), which laid the foundation for modern metallurgical practices by detailing the processes of mining, smelting, and metal extraction.

A metallurgist is a scientist who studies metals, including their behaviors, properties, elements and mixtures. Metallurgists can apply their expertise to engineering, mining and manufacturing to help develop processes and metallic parts for products.

Summary

Metallurgy is the science and technology of metals and alloys. The study of metallurgy can be divided into three general groups:

1. Process metallurgy

Process metallurgy is concerned with the extraction of metals from their ores and the refining of metals.

2.Physical metallurgy

Physical metallurgy is concerned with the physical and mechanical properties of metals affected by composition processing and environmental conditions.

3. Mechanical metallurgy

Mechanical metallurgy is concerned with the response of metals to applied forces.

Metallurgy has been leading human civilization from time immemorial. Man knew how to extract metals from ores, how to alloy metals to make them suitable for specific needs, and how to prepare high-purity metals and compounds for electronic applications. Looking back into the last century, it may be said that developments in metallurgy and materials science have played a significant role in several areas and impacted the economy and well-being of people. Every other branch of science and engineering has depended on advances in metallurgy to be applied in its domain. Development of superalloys for jet engine applications, development of carbon-carbon composites for wings of wide-bodied aircrafts, high-temperature superconductors, etc. are only a few examples to quote. It should also be mentioned here that the availability of excellent high-resolution techniques has contributed immensely to the understanding of the science and technology behind these developments, particularly from the point of view of structure-property correlations coupled with phase transformations.

Details

Metallurgy is a domain of materials science and engineering that studies the physical and chemical behavior of metallic elements, their inter-metallic compounds, and their mixtures, which are known as alloys.

Metallurgy encompasses both the science and the technology of metals, including the production of metals and the engineering of metal components used in products for both consumers and manufacturers. Metallurgy is distinct from the craft of metalworking. Metalworking relies on metallurgy in a similar manner to how medicine relies on medical science for technical advancement. A specialist practitioner of metallurgy is known as a metallurgist.

The science of metallurgy is further subdivided into two broad categories: chemical metallurgy and physical metallurgy. Chemical metallurgy is chiefly concerned with the reduction and oxidation of metals, and the chemical performance of metals. Subjects of study in chemical metallurgy include mineral processing, the extraction of metals, thermodynamics, electrochemistry, and chemical degradation (corrosion). In contrast, physical metallurgy focuses on the mechanical properties of metals, the physical properties of metals, and the physical performance of metals. Topics studied in physical metallurgy include crystallography, material characterization, mechanical metallurgy, phase transformations, and failure mechanisms.

Historically, metallurgy has predominately focused on the production of metals. Metal production begins with the processing of ores to extract the metal, and includes the mixture of metals to make alloys. Metal alloys are often a blend of at least two different metallic elements. However, non-metallic elements are often added to alloys in order to achieve properties suitable for an application. The study of metal production is subdivided into ferrous metallurgy (also known as black metallurgy) and non-ferrous metallurgy, also known as colored metallurgy.

Ferrous metallurgy involves processes and alloys based on iron, while non-ferrous metallurgy involves processes and alloys based on other metals. The production of ferrous metals accounts for 95% of world metal production.

Modern metallurgists work in both emerging and traditional areas as part of an interdisciplinary team alongside material scientists and other engineers. Some traditional areas include mineral processing, metal production, heat treatment, failure analysis, and the joining of metals (including welding, brazing, and soldering). Emerging areas for metallurgists include nanotechnology, superconductors, composites, biomedical materials, electronic materials (semiconductors) and surface engineering.

Extraction

Extractive metallurgy is the practice of removing valuable metals from an ore and refining the extracted raw metals into a purer form. In order to convert a metal oxide or sulphide to a purer metal, the ore must be reduced physically, chemically, or electrolytically. Extractive metallurgists are interested in three primary streams: feed, concentrate (metal oxide/sulphide) and tailings (waste).

After mining, large pieces of the ore feed are broken through crushing or grinding in order to obtain particles small enough, where each particle is either mostly valuable or mostly waste. Concentrating the particles of value in a form supporting separation enables the desired metal to be removed from waste products.

Mining may not be necessary, if the ore body and physical environment are conducive to leaching. Leaching dissolves minerals in an ore body and results in an enriched solution. The solution is collected and processed to extract valuable metals. Ore bodies often contain more than one valuable metal.

Tailings of a previous process may be used as a feed in another process to extract a secondary product from the original ore. Additionally, a concentrate may contain more than one valuable metal. That concentrate would then be processed to separate the valuable metals into individual constituents.

Metal and its alloys

Much effort has been placed on understanding iron–carbon alloy system, which includes steels and cast irons. Plain carbon steels (those that contain essentially only carbon as an alloying element) are used in low-cost, high-strength applications, where neither weight nor corrosion are a major concern. Cast irons, including ductile iron, are also part of the iron-carbon system. Iron-Manganese-Chromium alloys (Hadfield-type steels) are also used in non-magnetic applications such as directional drilling.

Other engineering metals include aluminium, chromium, copper, magnesium, nickel, titanium, zinc, and silicon. These metals are most often used as alloys with the noted exception of silicon, which is not a metal. Other forms include:

* Stainless steel, particularly Austenitic stainless steels, galvanized steel, nickel alloys, titanium alloys, or occasionally copper alloys are used, where resistance to corrosion is important.
* Aluminium alloys and magnesium alloys are commonly used, when a lightweight strong part is required such as in automotive and aerospace applications.
* Copper-nickel alloys (such as Monel) are used in highly corrosive environments and for non-magnetic applications.
* Nickel-based superalloys like Inconel are used in high-temperature applications such as gas turbines, turbochargers, pressure vessels, and heat exchangers.
* For extremely high temperatures, single crystal alloys are used to minimize creep. In modern electronics, high purity single crystal silicon is essential for metal-oxide-silicon transistors (MOS) and integrated circuits.

Additional Information

Metallurgy combines both the science and technology of metals and is involved in many facets of our modern society.

At its core, metallurgy involves scientists examining the microstructure of a metal, allowing then the mechanical properties of the metal to be determined, and empowers engineers to utilise that metal for various purposes such as welding or metalworking. Read on to learn about the fundamentals of metallurgy and how it relates to the mining industry.

Metallurgy definition

Metallurgy is best described as a field of materials science and engineering that studies the physical and chemical behaviours of metallic elements. Metallurgy also examines the inter-metallic compounds and how they can be mixed.

Usually, the term metallurgy refers to the commercial production and use of metals and it affects industries such as healthcare, transportation, defence, and entertainment through the creation and refinement of metals.

History

Early humans took an essential step toward the Metal Age when they discovered that metals such as copper could be melted and casted in moulds to form new shapes. Additionally, they made the discovery that metals could be separated from metal-bearing minerals. Eventually, our ancestors figured out they needed to add iron oxide to the process of melting copper to maintain the element's separation from the other associated minerals. Thus, they discovered flux, which is defined by Lexico as “a substance mixed with a solid to lower its melting point, used especially in soldering and brazing metals or to promote vitrification in glass or ceramics.”

These early stages of metallurgy primarily involved working with copper, gold, bronze, iron, brass, and other precious metals. These materials allowed early men to fashion weapons and even jewellery and such allowed successive peoples to create the civilisations we know today.

In more recent decades, metallurgy has evolved to primarily focus on the production of metals for commercial use. Metal production starts with extracting metals from ores through mineral processing, and oftentimes involves mixing metals in order to create alloys.

Types of metallurgy

Metallurgy can be separated into two categories, extractive and physical metallurgy. After metals have been extracted and processed, they can be used for production.

Extractive

Extractive metallurgy involves separating metal from ore or other chemical compound forms, allowing the metals to be processed and purified.

Extractive metallurgy consists of two main methods:

* Pyrometallurgy involves the use of heat, or thermal treatment, of minerals and ores. The heat causes a physical or chemical transformation of the materials allowing for metals to be extracted. The most common pyrometallurgical processes are roasting, smelting, and converting.
* Hydrometallurgy involves the use of water in processes to extract metals or compounds from their ores. This can be done through leaching, precipitation of insoluble compounds, and pressure reduction.

Physical

Physical metallurgy deals with processes of making useful products from and developing metallic alloys for manufacturing and construction. Physical metallurgy examines the metallic crystal structures, mechanical properties, electrical properties, magnetic properties, and chemical properties of metals.

Major components of physical metallurgy include:

* Powder metallurgy describes the processes in which materials or components are made from metal powders. Powder metallurgy enables operations to reduce the need to use metal removal processes and often results in lower costs.
* Alloying is the process of mixing several elements. Such mixtures, or alloys, can have properties superior to pure metals. Operations use alloying as a means to increase strength, increase corrosion resistance, and often reduce costs.

Production

In terms of production, metallurgy focuses on metallic components that are necessary for consumer or engineering products. Metal production can be divided into subsections of ferrous metallurgy and non-ferrous metallurgy. The difference between ferrous and non-ferrous metallurgy centres on the metals used in processes and alloys, with ferrous involving iron and non-ferrous involving other metals. According to USGS, ferrous metal production accounts for 95 percent of world metal production.

Production of metals may involve:

* Metalworking processes
* Heat treatment
* Plating
* Shot peening
* Thermal spraying
* Surface Treatment

Metallurgy in Mining:

Metallurgical Coal

Metallurgical coal is an essential ingredient in blast-furnace steel production and accounts for around 70% of global steel output. Also known as coking coal, this carbon-rich form of coal is used to make coke which is the primary source of carbon used in steel-making. The coal is sourced through mining.

Mineral Processing

Mining and mineral processing go hand in hand. Mineral processing starts with mining mineral products from the earth’s crust and then processing them in order to provide a more concentrated material for extractive metallurgy.

The operation of processing involves comminution, concentration, sampling, analysis and dewatering.

Metallurgical testing

Metallurgical testing is essential for verifying quality and adequacy of materials. Industries such as Oil & Gas, Desalination, and Nuclear rely on metallurgical testing as the materials used must be durable over sustained periods of time and hold up in the toughest conditions.

It typically consists of microscopic examination of a metal or alloy sample to determine the structure, grade, elasticity, tensile strength, grain size, hardness, or the presence of any defects.

A few types of metallurgical testing include:

* Chemical analysis
* Hardness testing
* Tensile Testing
* Fatigue Testing
* Impact Testing
* Microstructural analysis

This science of metals, discovered by early man, allows for many of our modern comforts, affecting everything from the buildings we live in to the gas we put in our cars. Modern metallurgists today work alongside engineers and scientists across varying industries and with varying materials. Meet the difference makers working in mining operations at Anglo American, who are helping to maintain and aid the furtherment of this essential technology by providing necessary ores and metals.

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