Metallurgy is defined as a technique for extracting metals in their natural, unprocessed state. Minerals are metal complexes combined with soil, limestone, sand, and rock. Metals are recovered from minerals for commercial applications at a fair cost and with very little labour. The metal obtained from these minerals is utilised in a variety of applications, including equipment, machinery, and machinery manufacture. Various extraction procedures, such as screen, pulp, and mineral oil, are used to remove metallic ore from mines. Metal recovery from sludge, heap leaching, and flotation are among the extraction methods.
Based on the type of metal, the metal ore mining market can be classified into aluminium, copper, iron, nickel, lead, zinc, and others. The metals such as aluminium, copper, and iron are widely used in numerous applications such as auto parts manufacturing, power plant, and construction equipment. The key driver for the growth of the metal ore mining market is the demand for these metals. The metals have the potential to reduce the carbon footprint in several applications and hence, manufacturers are finding them useful in the development of environmentally friendly products.
Why is metallurgy important?
It is used in the production of modern aeroplanes, vehicles (automobiles, railways, and ships), recreational vehicles, buildings, implanted devices, musical instruments, and various other things. Pyro metallurgy, hydrometallurgy, electrometallurgy, and bio metallurgy are all types of metallurgy. Pyro metallurgy is focused on the development of new and improved ore mixtures to be used in metal production, whereas hydrometallurgy aims at improving the purity of ore mixtures and extracting a higher proportion of useful metals. Bio-metallurgy, on the other hand, focuses on extracting precious metals from the constituents of natural minerals. In this way, it is possible to purify materials and produce high-grade alloys which are used in catalysts and electronics. This basic separation of metallurgy from other sciences is crucial because metallurgy is the most extensively applied science in modern times. Metallurgy is not only the result of technology.
The use of metallurgy technology and its applications
The development of metallurgy has yielded great results in the development of technology, and we have developed new materials that can be found in almost all modern machines and devices. The study of metallurgy can be broken down into three categories:
- Process Metallurgy - It is concerned with the extraction and refining of metals from their ores.
- Physical Metallurgy - It is concerned with how composition processing and ambient factors affect the physical and mechanical properties of metals.
- Mechanical Metallurgy - The response of metals to applied forces is the subject of mechanical metallurgy.
Metallurgical engineers are involved in all parts of modern civilisation and aim to address those demands in an ecologically friendly manner by creating processes and products that reduce waste, maximise energy efficiency, improve performance, and simplify recycling. These engineers are mainly involved in these areas:
- Surface Metallurgy - General research on metallurgical processes, fabrication of processing equipment, and material performance testing, including visualisation techniques
- Deep (extractive) Metallurgy - Surface mining and refining of metals, separation of metals by separation processes and their treatment into metals and non-metals, calcination, refining, and chemical processes.
- Recycling - incorporating or improving systems for recycling into the manufacturing process.
Metals and mineral products are everywhere around us with endless utility. Technology is also present in many places at virtually all times and places in modern life. Technology is dependent on metals, either as raw materials or as components for modern machinery, automobiles, appliances, tools, batteries, etc. Metal products are used in construction, cars, trucks, and telecommunications especially.
The percentage of most economies devoted to technology is high enough to demand metallurgy to help develop new materials and processes that benefit the economy, benefit consumers, and aid in technology’s development. Modern society must supply it with sufficient metals to support the high quality of life that people want.
Importance of Material Characterisation in Metallurgy
The importance of material characterisation can not be ruled out in metallurgy. Microscopic and macroscopic structures of metals are studied by metallurgists using metallographic techniques. In this technique, the metal surface is ground flat and polished using diamond paste. The sample is also etched to reveal the grain boundaries. The sample’s microstructure is then studied using an electron or light microscope.
Kemet offers a wide variety of sample preparation tools for metallographic inspection like cutting, mounting, grinding, and polishing machines. It also offers a variety of microscopes and accessories for the microstructure study of metals. These products can be utilised by metallurgists during the processing of metals and help in improving the processing parameters. Kemet also offer products for spectroscopy sample preparation, which can be used by metallurgists for material composition identification using XRF and OES being offered by Kemet.
Metallurgy vs Materials Science
Material science is the study of all materials, including metals, plastics, textiles, and natural materials. However, metallurgy is dedicated to the study of metals only. Most people believe that additional advancements in metal and mineral technologies will be critical to our economic and technological success in the twenty-first century. However, as we can see from history, a greater number of people will soon experience technologies that will be truly disruptive in the future. Understanding these technologies will be a vital skill for future engineers.
Tooling, manufacturing, and engineering
Metallurgical engineers seek to advance the metalworking industry as a whole to meet current and future metal demands. “Metallurgy” is widely used in connection with smelting, welding, machining, bending, extruding, tapping, soldering, casting, pumping, structural work, crushing, and other industrial processes. It has been closely associated with heavy industry, where the resulting metal was used for war production, ammunition, fuel, and other necessary materials. It is now often used to refer to small and medium-size smelting and welding companies. This includes smelting foundries (hot alloy steel, aluminium, nickel, etc.), tool makers (mechanical and metallurgical), component producers (e.g., screws and ducts), grinding operations, and others.
The operations of the metallurgical fields affect the environment of many regions worldwide, and in many countries, there are specialised systems and organisations to investigate and address environmental problems that may arise in the operations of metallurgical plants.
Metallurgy used in the extraction of copper and why?
The method used to extract copper from its ores depends on the nature of the ore. These methods are chemical separation, physical separation and chemical precipitation. Cuprum was the name given to it by the Romans since it was collected from the island of Cyprus. Once extracted from the earth and processed, Cuprum was known as “Austine” or “Copper”.
Metallurgy of Copper
It is defined as the manufacturing of hard, non-sparking and non-corrosive (low milling yields, superior fatigue resistance, high working temperatures, precision micro-processing and precision machining) copper alloys. It is mainly known for its ability to retain its hardness and high wear resistance.
The use of metals for metallurgy is commonly determined based on the properties of their powder structure. Depending on the nature of the alloy powder structure, specific chemical compounds are added to various parts of the annealed and work over phases of the process to control the rate of chemical reaction between the powder particles and to customise the properties of the alloy. Different forges are required for different parts of metallurgy.
- Step A - Concentration of Ore
To remove impurities, the ore must be heated and then allowed to cool. This is what happens to copper sulphate ore in Concentration.
- Step B - Roasting
Moisture and volatile contaminants are eliminated during this process. The ore is concentrated and roasted in the open air. When the ore is hot, it can be melted by a fire under pressure and then the molten metal can be poured into an open vessel where it is cooled by the air.
2CuFeS2 + O2 → Cu2S + 2FeS + SO2
S + O2 → SO2
Cuprous sulphide and ferrous sulphide are oxidised further to produce their oxides.
2Cu2S + 3O2 → 2Cu2O + 2SO2
2FeS + 3O2 →2FeO + 2SO2
- Step C - Copper Smelting
The copper smelter uses a large roasting furnace to generate heat for the oxidation process to extract metal from its ore.
FeO + SiO2 → FeSiO3
Cu2O + FeS → Cu2S + FeO
- Step D - Bessemerisation
It is the final stage of copper smelting. In a Bessemer converter, the air is blown into the molten copper mat. The heat generated during the Bessemerisation is not enough to completely evaporate the molten metal, so it remains in a liquid state. The stored Bessemerised copper is then removed and recycled.
2Cu2S + 3O2 → 2Cu2O + 2SO2
2Cu2O + Cu2S→ 6Cu + SO2
- Step E - Refining
Electrolytic refining purifies blister copper, which contains 98 per cent pure copper and 2% contaminants. This process is used to obtain metal of high purity. Copper is refined electrolytically.
Electrolytic Refining - Thorough electrolysis can separate copper from sulphur without the need to use chemicals. The separation is done by allowing a piece of blister copper to pass through two electrodes. The sulphur is broken down by a short circuit from the cathode (negative electrode) and the electrolytic solution oxidises it. The copper then flows to the cathode, leaving the sulphur behind.
Metal Part Manufacturing
Metal part manufacturing and metallurgy services include a variety of processes such as forming, stamping, machining, plating and forging, with the equipment and processes used in manufacturing different parts ranging from wire and cable, fasteners, springs, gears, fixtures, jewellery, to heavy vehicle chassis, machine tool heads, industrial screw and cabinet. Many companies in the industry use various forms of heat treatment techniques to control the hardness and toughness of the metal. Metal part manufacturing has traditionally been classified into various groups.
- A. Mineral processing - Before the advent of modern extraction and processing techniques, the basic and largest component of ore was the rock. As the mining advances, the ore became smaller and increasingly diverse in composition. The ore is processed to extract the metal. The materials extracted are melted and extracted. During processing, the metal content is reduced by metallurgical treatments, often carried out by large-scale industrial facilities. In addition, the substances not extracted from ore are often burned in the smelters to reduce the smelting waste. As a result, by-products from smelting are also burned. This is a major environmental issue and a problem for the whole world. In short, it is the accumulation of mineral products from the Earth's crust.
- B. Physical metallurgy - It involves the usage of metals as raw materials in manufacturing. It consists of more modern developments, such as the operations of the mining and metallurgy industries. It comprises all of the processes involved in the extraction, separation, treatment, production, refining, use, and distribution of metals.
- C. Extractive metallurgy - Chemical processing is one technique for converting minerals from inorganic compounds to usable metals and other commodities. A major part of minerals extracted from a variety of ores is usually discarded and treated in a smelting furnace to produce valuable metals, pigments, or other commodities.
Which metallurgy involves leaching
It is a common method for the treatment of some mineral materials. These processes are carried out to produce metal from ores or materials that are unreactive or have no elemental metal.
Metallurgy process of iron leaching
Iron is among the most commonly used metal in the metallurgical industry and it is mainly used in the manufacture of chemical compounds. However, metal is a very soft metal that can easily be removed and polished. However, the ferrous metal is not resistant to acids and many other agents. The removal of iron by other metal particles is known as iron leaching and is a major part of the metal part manufacturing and metallurgy services in the industry. The ferrous metal alloys are further processed into low iron alloy to remove the iron, and this is called iron oxide removal.
The iron leaching process ensures the cleaning of the steel by passing molten iron through its various parts to remove iron. This process requires direct contact of iron with steel components. The parts that come into contact with the iron are coated with a solution of the chemicals to work on the iron without corrosion. This method is widely used in steel part manufacturing and metallurgy services in the industry.
It is the process of converting iron ore into iron by removing inorganic solids (called hematite) by precipitating them through the solution in water or a liquid salt. The composition of hematite may be reduced by adding a solution of sodium hydroxide, though acid is rarely used as the reaction neutralises the aqueous environment in the furnace. Heap leach processing is a common way of reducing hematite in iron ores.
The form of metal parts manufacturing and metallurgy services includes taking advantage of the properties of specific metals and undergoing the reactions that are to be used to work them. Some of the metal components of the industry that are used in metal part manufacturing and metallurgy services include aluminium, copper, and zinc. Various metals are used in the process of metal leaching and electrolysis in the form of Cu-Au concentrates, Cu-Au ingots, Cu-Au melt, and Cu-Au scrap.
Electrolysis is a chemical process for changing the ferrous element (iron) in a particular ore into metallic iron. In extractive metallurgy, leaching is a process in which ore is treated with chemicals to turn the valuable metals inside it into soluble salts while the impurities remain insoluble.