Extractive Metallurgy Extractive metallurgy is the practice of removing metals from their ores or from the naturally occurring aggregates of minerals and refining the extracted raw metals into a purer form. The art of extracting metals from their ores dates back thousands of years3 with gold and copper being the first metals used by man. Although the techniques for the recovery of metals have developed steadily over the years, there is an ever increasing need for the further development of new and innovative techniques. This can largely be attributed to the rapidly increasing demand for metals in all aspects of the modern world, the decreasing supply of high-grade ores and the need for recycling. Separation is the essence of metal extraction …show more content…
It is a relatively modern discipline which was employed since the mid-1980s as an alternative to pyrometallurgy in the recovery of base metals. The general characteristics that differ from pyrometallurgic processes are parameters such as lower operating temperatures, low reaction rates, lower environmental impact, low unit costs, selective chemical reactions and recycling of …show more content…
This is because the physical properties and relative stabilities of metal compounds relate to the nature and disposition of ligands in the metal coordination spheres. Coordination chemistry refers to the chemistry of compounds formed by metals (Lewis acids) bonded to inorganic ions or molecules, or organic molecules, or their ions (Lewis bases) through donations of lone pairs of electrons.4 These coordination compounds can be ionic or neutral in nature and contains the metal ions/atoms closely surrounded by electron donor groups called ligands. This applies both to pyrometallurgy and
The objective of this experiment was to perform extraction. This is a separation and purification technique, based on different solubility of compounds in immiscible solvent mixtures. Extraction is conducted by shaking the solution with the solvent, until two layers are formed. One layer can then be separated from the other. If the separation does not happen in one try, multiple attempts may be needed.
The copper ions are transferred from the water where they are of a high concentr... ... middle of paper ... ... is likely to be placed and a thorough environmental impact assessment carried out to ensure that the processes do not cause undue environmental damageι. Finally governmental permission must be obtained before commercial activity can take placeι. References α - Article 1 from examination pack: Mining with microbes, John Merson. β - How hydrometallurgy and the SX/EW process made copper the "green" metal, William Dresher. γ - Article 2 from examination pack: Extracting copper from leaching solutions.
The purpose of this lab was to to cycle solid copper through a series of chemical forms and return it to its original form. A specific quantity of copper undergo many types of reactions and went through its whole cycle, then returned to its solid copper to be weighted. We observed 5 chemical reactions involving copper which are: Redox reaction (which includes all chemical reactions in which atoms have their oxidation state changed), double displacement reaction, precipitation reaction, decomposition reaction, and single displacement reaction.
The fortune of silver and gold discovered in Colorado’s mountains were locked inside complex ores consisting of granite, quartz and other metals that rendered them useless, unless they could be separated (Egan. NPS). Miners originally imported stamp mills and Spanish arrastras to extract the gold and silver but both these methods were inefficient and lost upwards of 70 percent of the sought after mineral (NPS). In 1867, chemistry professor Nathanial P. Hill discovered an efficient method called the Swansea process to separate the precious metals and opened the Boston Colorado Smelter in Blackhawk (NPS).
"Production of Refractory Metal Powders," in Powder Metal Technologies and Applications, vol. 7, 1998, pp. 188-201.
Iqbal, M. K. (2013, March 27). NED University of Engineering and Technology. Retrieved from Department of Metallurgy Engineering: http://www.neduet.edu.pk/myd/TE/MY%20302.pdf
Compounds are pure substances that contain atoms of two or more elements chemically combined in fixed ratios. In this lab, we observed two types of compounds, Ionic compounds and Covalent compounds. Ionic compounds are chemical compounds consisting of two or more ions that are held adjacent to each other by electrical attraction. “One of the ions, called an “anion,” has a negative charge, and the other is called a “cation,” and has a positive charge. “Cations” are usually metallic atoms and “anions” are either atoms of nonmetals or polyatomic ions. “ (1) A polyatomic ion is an ion that contains at least two atoms. A covalent compound is a compound in which the atoms that are bonded share at least one pair of valance electrons, the electrons that are located in the outermost shell of an atom, as opposed to transferring electrons from one atom to another. Covalent compounds are usually formed between nonmetal atoms.
Open pit mining. It is also known as strip mining. It begins with the removal of soils on the surface and inefficient rock to get at the ore below. This is only possible in some cases, generally when the ore is less than 120 metres below the surface.
the iron ore to iron. In the other cases of metals the most common way
The inefficiencies and the problems involved in making steels in the traditional form of ingots are alleviated by the continuous-casting process, which produces higher quality steels at reduced costs. Conceived in the 1860s, continuous or strand casting was first developed for casting nonferrous metal strips. The process now is used widely for steel production, with major productivity improvements and cost reductions.
Iron is this starting point for steelmaking which has performed as a backbone to the advancement of modern technology and is vital to the upbringing of the future. It acts as the predominant reason for the industrial revolution. The foundation that is iron, more industrially known as Cast Iron has been given the second honour as it is the one of the cheapest materials for engineering, when taken to molten temperatures it gains the ability to be cast into intricate shapes. Cast Iron has been sub-divided into 5 different classes when the composition is changed or tampered with. Each of these classes have different properties but in comparison with Steel which also has its grades ranging from low to high grade carbon steel which are just alloys of purified iron with carbon and hints of other metal elements such as Manganese and Nickel so the production of Steel products differs only slightly from the commercial production of Iron. Steel which is the easily formed, cheap and yet strong and tough allowing for it to be extremely versatile creating products ranging from paperclips to reinforcing elements in the construction of buildings and skyscrapers.
In the 1960s where hydrometallurgical processes grew in popularity, therewas a common perception that hydrometallurgy wasenvironmentally compliant. This was concluded from the perception that the low temperatures in comparison with pyrometallurgy meantlow energydemands andthe lack of air emissionswas often cited as demonstration that hydrometallurgical methods posed no threats to our environment, but this isnot the case (1)
(Khan): further states, here L are the Ligand and which is formed via the complete replacement of water molecules by other ligands can occur till the formation of the MLn complex. “n” is the coordination number of the metal ion and represents the maximum number of monodentate ligands which can be bound to it [8]
The complete process of continues casting leads to this result because the high efficiency of the whole process and reduced exposure of hot steel to air also reason to reduce scrap production
Others can be prevented by combining metals or the management of the metals environment. Other than gold, platinum and some other metals, metals are not found in their pure form as they are normally chemically bound to other substances in ores such as sulphides and oxides. Energy must be expended to extract the metals from the sulphides, oxides, to obtain pure metals and this can be done in a blast furnace. Pure metals strive to revert to their lowest energy state which they had as sulphides and oxides. One of the ways in which metals can revert to a low energy level is by corrosion. The products of corrosion of metals are often sulphides or oxides. There are many forms of corrosion such as general attack corrosion, localised corrosion and galvanic corrosion. General attack corrosion is a form of corrosion that attacks the entire surface of a metal structure and it is caused by chemical or electrochemical reactions. While general attack corrosion can cause a metal to fail, it is a predictable issue. It is possible to plan and manage for general attack