The scientific revolution 

The scientific revolution is a concept used by historians to describe the emergence of modern science during the early modern period, when developments in mathematics, physics, astronomy, biology (including human anatomy) and chemistry transformed the views of society about nature.  While its dates are debated, the publication in 1543 of Nicolaus Copernicus's De revolutionibus orbium coelestium (On the Revolutions of the Heavenly Spheres) is often cited as marking the beginning of the scientific revolution.The beginning of the scientific revolution, the Scientific Renaissance, was focused on the recovery of the knowledge of the ancients; this is generally considered to have ended in 1632 with publication of Galileo's Dialogue Concerning the Two Chief World Systems.^[8] The completion of the scientific revolution is attributed to the "grand synthesis" of Isaac Newton's 1687 Principia, that formulated the laws of motion and universal gravitation, and completed the synthesis of a new cosmology.

Great advances in science have been termed "revolutions" since the 18th century. In 1747, Clairaut wrote that "Newton was said in his own lifetime to have created a revolution".^[10] The word was also used in the preface to Lavoisier's 1789 work announcing the discovery of oxygen. "Few revolutions in science have immediately excited so much general notice as the introduction of the theory of oxygen ... Lavoisier saw his theory accepted by all the most eminent men of his time, and established over a great part of Europe within a few years from its first promulgation.

"A new view of nature emerged, replacing the Greek view that had dominated science for almost 2,000 years. Science became an autonomous discipline, distinct from both philosophy and technology and came to be regarded as having utilitarian goals. The scientific revolution is traditionally assumed to start with the Copernican Revolution (initiated in 1543) and to be complete in the "grand synthesis" of Isaac Newton's 1687 Principia. Much of the change of attitude came from Francis Baconwhose "confident and emphatic announcement" in the modern progress of science inspired the creation of scientific societies such as the Royal Society, and Galileo who championed Copernicus and developed the science of motion.

Rapid accumulation of knowledge, which has characterized the development of science since the 17th century, had never occurred before that time. The new kind of scientific activity emerged only in a few countries of Western Europe, and it was restricted to that small area for about two hundred years.

It is also true that many of the important figures of the scientific revolution shared in the general Renaissance respect for ancient learning and cited ancient pedigrees for their innovations. Nicolaus Copernicus (1473–1543),^[25] Kepler (1571–1630),^[26] Newton (1642–1727),^[27] and Galileo Galilei (1564–1642)^{[1][2][3][28]} all traced different ancient and medieval ancestries for the heliocentric system. In the Axioms Scholium of his Principia, Newton said its axiomatic three laws of motion were already accepted by mathematicians such as Huygens (1629–1695), Wallace, Wren and others. While preparing a revised edition of his Principia, Newton attributed his law of gravity and his first law of motion to a range of historical figures.

By the end of the scientific revolution the qualitative world of book-reading philosophers had been changed into a mechanical, mathematical world to be known through experimental research. Though it is certainly not true that Newtonian science was like modern science in all respects, it conceptually resembled ours in many ways. Many of the hallmarks of modern science, especially with regard to its institutionalization and professionalization, did not become standard until the mid-19th century.

The term British empiricism came into use to describe philosophical differences perceived between two of its founders Francis Bacon, described as empiricist, and René Descartes, who was described as a rationalist. Thomas Hobbes, George Berkeley, and David Hume were the philosophy's primary exponents, who developed a sophisticated empirical tradition as the basis of human knowledge.

Bacon proposed a great reformation of all process of knowledge for the advancement of learning divine and human, which he called Instauratio Magna (The Great Instauration). For Bacon, this reformation would lead to a great advancement in science and a progeny of new inventions that would relieve mankind's miseries and needs. Bacon considered that it is of greatest importance to science not to keep doing intellectual discussions or seeking merely contemplative aims, but that it should work for the bettering of mankind's life by bringing forth new inventions, having even stated that "inventions are also, as it were, new creations and imitations of divine works".^{[35][page needed]} He explored the far-reaching and world-changing character of inventions, such as the printing press, gunpowder and the compass.

Galileo Galilei has been called the "father of modern observational astronomy",^[42] the "father of modern physics",^[43][44] the "father of science",^[44][45] and "the Father of Modern Science".^[46] His original contributions to the science of motion were made through an innovative combination of experiment and mathematics.  his work marked another step towards the eventual separation of science from both philosophy and religion; a major development in human thought. He was often willing to change his views in accordance with observation. In order to perform his experiments, Galileo had to set up standards of length and time, so that measurements made on different days and in different laboratories could be compared in a reproducible fashion. This provided a reliable foundation on which to confirm mathematical laws using inductive reasoning.

Galileo showed a remarkably modern appreciation for the proper relationship between mathematics, theoretical physics, and experimental physics. He understood the parabola, both in terms of conic sections and in terms of the ordinate (y) varying as the square of the abscissa (x). Galilei further asserted that the parabola was the theoretically ideal trajectory of a uniformly accelerated projectile in the absence of friction and other disturbances. He conceded that there are limits to the validity of this theory, noting on theoretical grounds that a projectile trajectory of a size comparable to that of the Earth could not possibly be a parabola,^[50] but he nevertheless maintained that for distances up to the range of the artillery of his day, the deviation of a projectile's trajectory from a parabola would be only very slight.

 Gravity, interpreted as an innate attraction between every pair of particles of matter, was an occult quality in the same sense as the scholastics' "tendency to fall" had been.... By the mid eighteenth century that interpretation had been almost universally accepted, and the result was a genuine reversion (which is not the same as a retrogression) to a scholastic standard. Innate attractions and repulsions joined size, shape, position and motion as physically irreducible primary properties of matter.

The French established the Academy of Sciences in 1666. In contrast to the private origins of its British counterpart, the Academy was founded as a government body by Jean-Baptiste Colbert. Its rules were set down in 1699 by King Louis XIV, when it received the name of 'Royal Academy of Sciences' and was installed in the Louvre in Paris.

Practical attempts to improve the refining of ores and their extraction to smelt metals was an important source of information for early chemists in the 16th century, among them Georg Agricola (1494–1555), who published his great work De re metallica in 1556.^[82] His work describes the highly developed and complex processes of mining metal ores, metal extraction and metallurgy of the time. His approach removed the mysticism associated with the subject, creating the practical base upon which others could build.

English chemist Robert Boyle (1627–1691) is considered to have refined the modern scientific method for alchemy and to have separated chemistry further from alchemy.^[84] Although his research clearly has its roots in the alchemical tradition, Boyle is largely regarded today as the first modern chemist, and therefore one of the founders of modern chemistry, and one of the pioneers of modern experimental scientific method. Although Boyle was not the original discover, he is best known for Boyle's law, which he presented in 1662:^[85] the law describes the inversely proportional relationship between the absolute pressure and volume of a gas, if the temperature is kept constant within a closed system. Importantly, he advocated a rigorous approach to scientific experiment: he believed all theories must be tested experimentally before being regarded as true. The work contains some of the earliest modern ideas of atoms, molecules, and chemical reaction, and marks the beginning of the history of modern chemistry. Robert Boyle also worked frequently at the new science of electricity, and added several substances to Gilbert's list of electrics. He left a detailed account of his researches under the title of Experiments on the Origin of Electricity.^[92] Boyle, in 1675, stated that electric attraction and repulsion can act across a vacuum. One of his important discoveries was that electrified bodies in a vacuum would attract light substances, this indicating that the electrical effect did not depend upon the air as a medium. He also added resin to the then known list of electrics.

John Napier introduced logarithms as a powerful mathematical tool. With the help of the prominent mathematician Henry Briggstheir logarithmic tables embodied a computational advance that made calculations by hand much quicker.^[97] His Napier's bones used a set of numbered rods as a multiplication tool using the system of lattice multiplication. The way was opened to later scientific advances, particularly in astronomy and dynamics.

Abraham Darby I (1678–1717) was the first, and most famous, of three generations of the Darby family who played an important role in the Industrial Revolution. He developed a method of producing high-grade iron in a blast furnace fueled by coke rather than charcoal. This was a major step forward in the production of iron as a raw material for the Industrial Revolution.

Evangelista Torricelli (1607–1647) was best known for his invention of the mercury barometer. The motivation for the invention was to improve on the suction pumps that were used to raise water out of the mines. Torricelli constructed a sealed tube filled with mercury, set vertically into a basin of the same substance. The column of mercury fell downwards, leaving a Torricellian vacuum above.

Metallurgy

The seven Metals of Antiquity were

1. Gold (ca) 6000 BC
2. Copper,(ca) 4200 BC
3. Silver,(ca) 4000 BC
4. Lead, (ca) 3500 BC
5. Tin, (ca) 1750 BC
6. Iron,smelted, (ca) 1500 BC
7. Mercury, (ca) 750 BC

Out of the Metals of Antiquity, five metals, gold, silver, copper, iron and mercury can be found in their native states, but the occurrence of these metals was not abundant. 

There are three different methods for the conversion of metallic oxides into metal.

• Pyro metallurgy: It is a high temperature process in which ore particles undergo reactions to form intermediate compounds for further processing or to get converted into their elemental or metallic state. It involves the heating of the material obtained from roasting or calcination, in the presence of a suitable reducing agent. During the heating process some chemical substance is added which further reacts with gangue at high temperature and is known as flux.
• Hydro metallurgy: The process of dissolving an ore in a suitable reagent followed by the extraction of the metal either by electrolysis or displacement of the metal by a more electropositive metal is called hydro metallurgy. This process uses aqueous solutions to extract metals from their ores. The most common hydro metallurgical process is the extraction of gold and silver.
• Electro metallurgy: Electro metallurgy is the metallurgical processes in which the extraction of metal takes place in an electrolytic cell. The molten metallic salt is taken as the electrolyte in the cell, with suitable electrodes. The molten metallic salt dissociates in pure metal and is collected at the cathode. For example, Dow process is used for the extraction of magnesium from its salt, magnesium chloride, which is the main component of sea water.

MgCl₂ â†’ Mg²⁺ + 2Cl^-

Iron metallurgy

Iron is usually extracted by using oxide ores like

• Haematite (Fe₂O₃)
• Limonite ( Fe₂O₃ .3H₂O)
• Magnetite (Fe₃O₄)
• Siderite (FeCO₃)
• Iron pyrites (FeS)

Out of these ores, haematite is the best ore of iron. Iron metallurgy involves the following steps.

1. Concentration: Since iron ores are heavier than their impurities, hydraulic washing is used for the concentration of the ore. For iron sulphide, the froth-flotation method is a good method for concentration or ore-dressing.
2. Calcination: The oxide ores of iron are heated in the presence of limited oxygen in a reverberatory furnace. This process is used to remove moisture and non-metallic impurities associated with the ore. The ferrous oxide present in the ore is oxidized to ferric oxide.
3. Smelting: The calcined ore is reduced with carbon in a blast furnace at high temperature. The blast furnace is a tall cylindrical furnace made up of steel and lined with fire bricks. It is slightly narrow at the top and wide at center with a narrow bottom. There is a cup and cone arrangement in the furnace which helps to feed the charge from the top without letting any gas from inside escape. The charge consists of ore, coke and limestone in a 8:4:1 ratio. The temperature of the blast furnace is maintained at 1000 K by blowing hot air in the furnace. Different reactions take place at different temperatures.

History of Metallurgy

Smelting of iron oxide with charcoal demanded a high temperature, and, since the melting temperature of iron at 1,540° C (2,800° F) was not attainable then, the product was merely a spongy mass of pasty globules of metal intermingled with a semiliquid slag. This product, later known as bloom, was hardly usable as it stood, but repeated reheating and hot hammering eliminated much of the slag, creating wrought iron, a much better product.

By 1000 bc iron was beginning to be known in central Europe. Its use spread slowly westward; iron making was fairly widespread in Great Britainat the time of the Roman invasion in 55 bc. In Asia iron was also known in ancient times, in China by about 700 bc.

Lead was removed from the silver by cupellation, a process of great antiquity in which the alloy was melted in a shallow porous clay or bone-ash receptacle called a cupel. A stream of air over the molten mass preferentially oxidized the lead. Its oxide was removed partially by skimming the molten surface; the remainder was absorbed into the porous cupel. Silver metal and any gold were retained on the cupel. The lead from the skimmings and discarded cupels was recovered as metal upon heating with charcoal.

Native gold itself often contained quite considerable quantities of silver. These silver-gold alloys, known as electrum, may be separated in a number of ways, but presumably the earliest was by heating in a crucible with common salt. In time and with repetitive treatments, the silver was converted into silver chloride, which passed into the molten slag, leaving a purified gold.

 By 100 bc mercury was known and was produced by heating the sulfide mineral cinnabar and condensing the vapours.

During the 16th century, metallurgical knowledge was recorded and made available. Two books were especially influential. One, by the Italian Vannoccio Biringuccio, was entitled De la pirotechnia (Eng. trans., The Pirotechnia of Vannoccio Biringuccio, 1943). The other, by the German Georgius Agricola, was entitled De re metallica. Biringuccio was essentially a metalworker, and his book dealt with smelting, refining, and assay methods (methods for determining the metal content of ores) and covered metal casting, molding, core making, and the production of such commodities as cannons and cast-iron cannonballs. His was the first methodical description of foundry practice.

Agricola, on the other hand, was a miner and an extractive metallurgist; his book considered prospecting and surveying in addition to smelting, refining, and assay methods. He also described the processes used for crushing and concentrating the ore and then, in some detail, the methods of assaying to determine whether ores were worth mining and extracting. Some of the metallurgical practices he described are retained in principle today.

In England, the gradual exhaustion of timber led first to prohibitions on cutting of wood for charcoal and eventually to the introduction of coke, derived from coal, as a more efficient fuel. Thereafter the iron industry expanded rapidly in Great Britain, which became the greatest iron producer in the world. The crucible process for making steel, introduced in England in 1740, by which bar iron and added materials were placed in clay crucibles heated by coke fires, resulted in the first reliable steel made by a melting process.

it was difficult to keep the carbon content low enough so that the metal remained ductile. This difficulty was overcome by melting high-carbon pig iron from the blast furnace in the puddling process, invented in Great Britain in 1784.

The most important development of the 19th century was the large-scale production of cheap steel. Prior to about 1850, the production of wrought iron by puddling and of steel by crucible melting had been conducted in small-scale units without significant mechanization.

 Another major advance was Henry Bessemer’s process, patented in 1855 and first operated in 1856, in which air was blown through molten pig iron from tuyeres set into the bottom of a pear-shaped vessel called a converter. Heat released by the oxidation of dissolved silicon, manganese, and carbon was enough to raise the temperature above the melting point of the refined metal (which rose as the carbon content was lowered) and thereby maintain it in the liquid state. Very soon Bessemer had tilting converters producing 5 tons in a heat of one hour, compared with four to six hours for 50 kilograms (110 pounds) of crucible steel and two hours for 250 kilograms of puddled iron

Neither the open-hearth furnace nor the Bessemer converter could remove phosphorus from the metal, so that low-phosphorus raw materials had to be used. This restricted their use from areas where phosphoric ores, such as those of the Minette range in Lorraine, were a main European source of iron. The problem was solved by Sidney Gilchrist Thomas, who demonstrated in 1876 that a basic furnace lining consisting of calcined dolomite, instead of an acidic lining of siliceous materials, made it possible to use a high-lime slag to dissolve the phosphates formed by the oxidation of phosphorus in the pig iron. This principle was eventually applied to both open-hearth furnaces and Bessemer converters.

The next significant stage was the introduction of cheap oxygen, made possible by the invention of the Linde-Frankel cycle for the liquefaction and fractional distillation of air. The Linz-Donawitz process, invented in Austria shortly after World War II, used oxygen supplied as a gas from a tonnage oxygen plant, blowing it at supersonic velocity into the top of the molten iron in a converter vessel. As the ultimate development of the Bessemer/Thomas process, oxygen blowing became universally employed in bulk steel production.

Chemistry of Uranium ore processing

Primary uranium minerals, include uraninite and pitchblende (the latter a variety of uraninite). The uranium in these two ores occurs in the form of uranium dioxide, which—owing to oxidation—can vary in exact chemical composition from UO₂ to UO_2.67. Other uranium ores of economic importance are autunite, a hydrated calcium uranyl phosphate; tobernite, a hydrated copper uranyl phosphate; coffinite, a black hydrated uranium silicate; and carnotite, a yellow hydrated potassium uranyl vanadate.

Uranium ores occur in deposits that are both near-surface and very deep (e.g., 300 to 1,200 metres, ). The deep ores sometimes occur in seams as thick as 30 metres. 

Roasted uranium ores are leached of their uranium values by both acidic and alkaline aqueous solutions. For the successful operation of all leaching systems, uranium must either be initially present in the more stable hexavalent state or be oxidized to that state in the leaching process.

Acid leaching is commonly performed by agitating an ore-leach mixture for 4 to as long as 48 hours at ambient temperature. Except in special circumstances, sulfuric acid is the leachant used; it is supplied in amounts sufficient to obtain a final leach liquor at about pH 1.5. Sulfuric acid leaching circuits commonly employ either manganese dioxide or chlorate ion to oxidize the tetravalent uranium ion (U⁴⁺) to the hexavalent uranyl ion (UO₂²⁺). Typically, about 5 kilograms (11 pounds) of manganese dioxide or 1.5 kilograms of sodium chlorate per ton suffice to oxidize tetravalent uranium. In any case, the oxidized uranium reacts with the sulfuric acid to form a uranyl sulfate complex anion, [UO₂(SO₄)₃]^4-.

Uranium ores that contain significant amounts of basic minerals such as calcite or dolomite are leached with 0.5 to 1 molar sodium carbonate solutions. Although a variety of reagents has been studied and tested, oxygen is the uranium oxidant of choice. Typically, candidate ores are leached in air at atmospheric pressure and at 75° to 80° C (167° to 175° F) for periods that vary with the particular ore. The alkaline leachant reacts with uranium to form a readily soluble uranyl carbonate complex ion, [UO₂(CO₃)₃]^4-.

The complex ions [UO₂(CO₃)₃]^4- and [UO₂(SO₄)₃]^4- can be sorbed from their respective leach solutions by ion-exchange resins. These special resins—characterized by their sorption and elution kinetics, particle size, stability, and hydraulic properties—can be used in a variety of processing equipment—e.g., fixed-bed, moving-bed, basket resin-in-pulp, and continuous resin-in-pulp. Conventionally, sodium and ammonium chloride or nitrate solutions are then used to elute the sorbed uranium from the exchange resins.

Uranium can also be removed from acidic ore leach-liquors through solvent extraction. In industrial methods, alkyl phosphoric acids—e.g., di(2-ethylhexyl) phosphoric acid—and secondary and tertiary alkyl amines are the usual solvents. As a general rule, solvent extraction is preferred over ion-exchange methods for acidic leachates containing more than one gram of uranium per litre. Solvent extraction is not useful for recovery of uranium from carbonate leach liquors, however.

Prior to final purification, uranium present in acidic solutions produced by the ion-exchange or solvent-extraction processes described above, as well as uranium dissolved in carbonate ore leach solutions, is typically precipitated as a polyuranate. From acidic solutions, uranium is precipitated by addition of neutralizers such as sodium hydroxide, magnesia, or (most commonly) aqueous ammonia. Uranium is usually precipitated as ammonium diuranate, (NH₄)₂U₂O₇. From alkaline solutions, uranium is most often precipitated by addition of sodium hydroxide, producing an insoluble sodium diuranate, Na₂U₂O₇. It can also be precipitated by acidification (to remove carbon dioxide) and then neutralization (to remove the uranium) or by reduction to less soluble tetravalent uranium. In all cases, the final uranium precipitate, commonly referred to as yellow cake, is dried. In some cases—e.g., with ammonium diuranate—the yellow cake is ignited, driving off the ammonia and oxidizing the uranium to produce uranium trioxide (UO₃) or the more complex triuranium octoxide (U₃O₈). In all cases, the final product is shipped to a central uranium-purification facility.

Uranium meeting nuclear-grade specifications is usually obtained from yellow cake through a tributyl phosphate solvent-extraction process. First, the yellow cake is dissolved in nitric acid to prepare a feed solution. Uranium is then selectively extracted from this acid feed by tributyl phosphate diluted with kerosene or some other suitable hydrocarbon mixture. Finally, uranium is stripped from the tributyl phosphate extract into acidified water to yield a highly purified uranyl nitrate, UO₂(NO₃)₂.

Uranyl nitrate is produced by the ore-processing operations described above as well as by solvent extraction from irradiated nuclear reactor fuel . In either case, it is an excellent starting material for conversion to uranium metal or for eventual enrichment of the uranium-235 content. Both of these routes conventionally begin with calcining the nitrate to UO₃ and then reducing the trioxide with hydrogen to uranium dioxide (UO₂). Subsequent treatment of powdered UO₂ with gaseous hydrogen fluoride (HF) at 550° C (1,025° F) produces uranium tetrafluoride (UF₄) and water vapour, as in the following reaction:

UO2 + 4HF---> UF4 + 2H2O

This hydrofluorination process is usually performed in a fluidized-bed reactor

Conversion to uranium metal is accomplished through the Ames process, in which UF₄ is reduced with magnesium (Mg) at temperatures exceeding 1,300° C (2,375° F). (In an often-used modification of the Ames process, calcium metal is substituted for magnesium.) Because the vapour pressureof magnesium metal is very high at 1,300° C, the reduction reaction is performed in a refractory-lined, sealed container, or “bomb.” Bombs charged with granular UF₄ and finely divided Mg (the latter in excess) are heated to 500° to 700° C (930° to 1,300° F), at which point an exothermic  reaction occurs. The heat of reaction is sufficient to liquefy the conversion contents of the bomb, which are essentially metallic uranium and a slag of magnesium fluoride (MgF₂):

UF4 +2Mg--> U + 2MgF2

When the bomb is cooled to ambient temperature, the massive uranium metal obtained is, despite its hydrogen content, the best-quality uranium metal available commercially and is well suited for rolling into fuel shapes for nuclear reactors.

Uranium tetrafluoride can also be fluorinated at 350° C (660° F) with fluorine gas to volatile uranium hexafluoride (UF₆), which is fractionally distilled to produce high-purity feedstock for isotopic enrichment. Any of several methods—gaseous diffusion, gas centrifugation, liquid thermal diffusion—can be employed to separate and concentrate the fissile uranium-235 isotope into several grades, from low-enrichment (2 to 3 percent uranium-235) to fully enriched (97 to 99 percent uranium-235). Low-enrichment uranium is typically used as fuel for light-water nuclear reactors.

After enrichment, UF₆ is reacted in the gaseous state with water vapour to yield hydrated uranyl fluoride (UO₂F₂ · H₂O). Hydrogen reduction of the uranyl fluoride produces powdered UO₂, which can be used to prepare ceramic nuclear reactor fuel. In addition, UO₂ obtained from enriched UF₆ or from UF₆ that has been depleted of its uranium-235 content can be hydrofluorinated to yield UF₄, and the tetrafluoride can then be converted to uranium metal in the Ames process described above.