Adrien C. B. Chenot (born on August 30, 1803; died November 27, 1855) was a French engineer best known for his inventions in

metallurgy 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 sc ...

as well as his research on manufactured gases. He is notably the inventor of one of the first modern methods of direct reduction of iron ore, based on the use of coal reacting with the ore in retorts . He exhibited the first samples of pre-reduced iron ore at the Lisbon Universal Exhibition of 1849, and was awarded the "''Grandes Medailles d'Or''" (Gold Medal of Honour) at the Paris Universal Exposition of 1855.

Early life

Born in

Bar-sur-Aube Bar-sur-Aube (, literally ''Bar on Aube'') is a commune and a sub-prefecture in the Aube department in the Grand Est region of France. Surrounded by hills and Champagne vineyards, the city is traversed by the river Aube, from which it derives ...

, he went to school in Nancy then in Paris. In 1820, he entered the

Ecole des mines de Paris Mines Paris - PSL, officially École nationale supérieure des mines de Paris (until May 2022 Mines ParisTech, also known as École des mines de Paris, ENSMP, Mines de Paris, les Mines, or Paris School of Mines), is a French grande école and a c ...

, and on leaving this school, he was attached to the General Secretariat of the Department of Bridges and Roads. He left this post some time after to operate mines in

Auvergne Auvergne (; ; oc, label=Occitan, Auvèrnhe or ) is a former administrative region in central France, comprising the four departments of Allier, Puy-de-Dôme, Cantal and Haute-Loire. Since 1 January 2016, it has been part of the new region Auverg ...

Career

In 1826, Chenot was asked by

Auguste de Marmont Auguste Frédéric Louis Viesse de Marmont (20 July 1774 – 22 March 1852) was a French general and nobleman who rose to the rank of Marshal of the Empire and was awarded the title (french: duc de Raguse). In the Peninsular War Marmont succeede ...

, Duke of Raguse, to carry out metallurgical studies at

Châtillon-sur-Saône Châtillon-sur-Saône (, literally ''Châtillon on Saône'') is a commune in the Vosges department in Grand Est in northeastern France. See also *Communes of the Vosges department The following is a list of the 507 communes of the Vosges depa ...

, where he filed a first patent relating to the direct manufacture of iron by treating powdered ore, mixed with coal, on a hearth of reverberatory furnace. In 1832, he built a first direct reduction device at his home in

Haute-Saône Haute-Saône (; Arpitan: ''Hiôta-Sona''; English: Upper Saône) is a department in the Bourgogne-Franche-Comté region of northeastern France. Named after the river Saône, it had a population of 235,313 in 2019.Clichy-la-Garenne. Chenot was also interested in the production of manufactured gas, more particularly wood gas for supplying reverberation ovens. Until 1842, he worked and patents on gases, shale oils, lead sulphates, etc. He invented the use of alkalis for the dephosphorization and desulphurization of manufactured gases, and proposed a classification of combustible gases based on their reactivity with alkalis. He studied the use of porous materials, sponges, to improve gas production, etc. In 1849, he returned to his metallurgical research related to the reduction of metal oxides. The development of direct metallurgy, which consists in producing metals without going through the stages of melting (in the

blast furnace A blast furnace is a type of metallurgical furnace used for smelting to produce industrial metals, generally pig iron, but also others such as lead or copper. ''Blast'' refers to the combustion air being "forced" or supplied above atmospheric ...

) and refining (then carried out painfully by puddling), requires a scientific optimization of the chemical reactions previously carried out empirically in low furnaces . This approach seemed to him capable of revolutionizing metallurgy:

“In fact, releasing heat by oxidation and absorbing it by reduction, giving rise to electro-chemical and electro-dynamic currents, which rapidly distribute the local effects in the universe, such is the great mechanism which functions in nature. by the actions of nascent bodies or sponges. The science of the manufacture of metallic sponges must therefore henceforth serve as a basis not only for the metallurgical art, but for all others."

- BC Chenot, 1849 Its knowledge of the production of reducing gases is essential for the development of its oxide reduction processes: it simultaneously improves the obtaining of the gases necessary for its metallurgical processes, just like the processes themselves. He also understood the importance of the purity of the ore to ensure an economic interest in direct reduction processes, and invented an "electrotrieuse" which removes a large part of the raw minerals from their sterile gangue. His research concerns the obtaining of metal sponges from many bodies (aluminum, calcium, silicon, barium, etc.), of which he is also studying the properties of their alloys with iron.

Death

Chenot died suddenly and unexpectedly in November 1855 after falling out of a window apparently due to disorientation and nausea from experimenting

carbon monoxide poisoning Carbon monoxide poisoning typically occurs from breathing in carbon monoxide (CO) at excessive levels. Symptoms are often described as "flu-like" and commonly include headache, dizziness, weakness, vomiting, chest pain, and confusion. Large e ...

. He was only 52 years old and active in his final days, although very weakened by the toxic gases inhaled during his experiments.

Contributions

Chenot method of direct reduction

The Chenot process is one of the very first direct reduction processes to succeed blast furnaces. The method took over 25 years to develop. The method is a retort furnace 10m high, 1.5m wide and 0.5m deep, associated in pairs and whose walls are heated by 4 coal fires. Retorts are loaded from above with a mixture of charcoal and iron ore, and their contents are discharged downwards as soon as the load is sufficiently reduced.Emmanuel-Louis Grüner, , t. second, procédé de métallurgiques, chauffage et fusion, grillage, affinage et réduction, Dunod, 1878 Despite the presence of a cooler under the retorts, designed to restore its heat to the loaded ore, the “Heating method is ��very imperfect; more heat is lost outside than it is used in the retort itself”. Indeed, to produce one tonne of pre-reduced iron ore, the Chenot process consumes 350 kg of charcoal and 780 kg of hard coal, which is much more than the blast furnaces of the time which carried out both smelting and reduction, by consuming less than 1000 kg of coke; the thermal efficiency of the process is then estimated at 26%, compared to 70 or even 80% of blast furnaces of the period. Thus, Isaac Lowthian Bellestimates the fuel cost 2.3 times higher, and the loss 3.5 times higher than a blast furnace and

Bessemer converter The Bessemer process was the first inexpensive industrial process for the mass production of steel from molten pig iron before the development of the open hearth furnace. The key principle is removal of impurities from the iron by oxidation with ...

. The ore used must be of excellent quality (80 to 82% hematite ), and stays for nearly 8 days in the apparatus (half the time in the retort, then in the cooler ). However, loading and emptying are partial and therefore more regular: there is a processing capacity of 1.2 to 1.5 tonnes per day of ore, i.e. 400 tonnes per year per unit of production, far from the production capacities of blast furnaces. from epoch . The iron sponge obtained contains 13% of waste rock, which must be heated and slashed, or melted, to obtain a usable mass of iron.

Impact

However, the process strongly marked its contemporaries because it exploited and validated the new understanding of chemical oxidation-reduction reactions in metallurgy . But, although it illustrates the perfect knowledge of its author of modern metallurgy, it raises many questions as to its profitability:

"It is difficult to understand today that the Chenot process was originally considered to be intended to revolutionize the iron industry, whereas it can only be applied to absolutely pure ores, all of which are the times that one does not resolve to remelt the sponge in the crucible or in the Martin oven. It is also not understood that, in a single factory, ten furnaces could have been assembled, representing a considerable expense, to manufacture a product involving, per tonne of sponge, the consumption of 1,400 kilos of charcoal for the reduction and 1,723 kilos of hard coal for heating retorts : the sponge could not be transformed into iron except by agglomerating it in the Comtois fire at the cost of a new consumption of coal."

- A. Ledebur, Operational in the 1850s in a few factories in France (at the Chenot de Clichy factory in 1855, at

Pontcharra Pontcharra (; frp, Pont-Charrâ) is a Communes of France, commune in the Isère Departments of France, department in southeastern France. Population Personalities Pontcharra is the birthplace of former Formula One driver René Arnoux. Pierre ...

in 1856 and

Hautmont Hautmont () is a commune in the Nord department in northern France. It is southwest of the centre of Maubeuge, and has 14,500 residents. On August 3, 2008, a narrow but strong F4 tornado swept through the town, as well as Maubeuge, Neuf-Mesn ...

in 1857), in Spain (at

Barakaldo Barakaldo ( es, Baracaldo; eu, Barakaldo ) is a municipality located in the Biscay province in the Basque Country. Located on the Left Bank of the Estuary of Bilbao, the city is part of Greater Bilbao, has a population at 100,881. Barakaldo ha ...

in 1852), in Belgium (at Couillet in 1856) and in Italy. The process was also tried in the United States, where a slightly improved variant by Blair operated in Pittsburg until 1846. Another furnace, in Ravensdale (

North Staffordshire The federation of Stoke-on-Trent was the 1910 amalgamation of the six Staffordshire Potteries towns of Burslem, Tunstall, Stoke-upon-Trent, Hanley, Fenton and Longton into the single county borough of Stoke-on-Trent. An anomaly in the history ...

), started up in 1875, without proving to be more profitable. The Englishman Yates takes advantage of the fact that the hearths heating the retorts can be fed by a gas instead of coal, and in this sense proposes a modification of the Chenot process in 1860.J. Percy (trad. traduction supervisée par l'auteur), , Paris, Librairie polytechnique de Noblet et Baudry éditeur, 1865 Also in 1860, the American Renton then, in 1875, the Frenchman Verdié in

Firminy Firminy (; oc, Frominiu) is a commune in the Loire department in central France. It lies on the river Ondaine, 13 km southwest of Saint-Étienne by rail. History The ancient name of the town was ''Firminiaco'' or ''Firminiacus'' (lit. "pla ...

, proposed a more original variant, consisting in using the waste heat from the chimney of the puddling furnaces to heat a retort of reduced size. But, if “at first glance, the operation seems rational, the reduction is incomplete, the waste high, the bottom of the retort ��quickly corroded. It is always difficult to coordinate, in one oven, two separate operations: reducing waste heat and refining on the sole of the lamppost". Finally, his son Eugène Chenot continued his father's studies by building in 1862, at the Ramade plant in Clichy, a direct reduction furnace foreshadowing the continuous processes of direct reduction with gases alone, which however did not succeed. better than the process developed by his father. The steel is obtained by soaking a part (about a quarter) of the iron sponge in a carburized liquid (wood tar, etc.), then by melting the carburized sponges with the non-carburized sponges. The steel obtained in this way is deemed to be of good quality, although there are better ones. In 1867, the cost price of a ton of Chenot steel produced in Clichy was estimated at 1,097.29 Fr, and 500 Fr at Baracaldo where it was popular for use as horse-shoes nails.

Carbon monoxide

Carbon monoxide Carbon monoxide (chemical formula CO) is a colorless, poisonous, odorless, tasteless, flammable gas that is slightly less dense than air. Carbon monoxide consists of one carbon atom and one oxygen atom connected by a triple bond. It is the simple ...

served as a

reducing agent In chemistry, a reducing agent (also known as a reductant, reducer, or electron donor) is a chemical species that "donates" an electron to an (called the , , , or ). Examples of substances that are commonly reducing agents include the Earth meta ...

in the Chenot method. Chenot was among the first to report the toxicity of

. He suffered from the after-effects of carbon monoxide poisoning suffered during his numerous experiments. He was particularly seriously intoxicated in 1846, while working in the factories of the Marquis de Sassenay, in

Prussia Prussia, , Old Prussian: ''Prūsa'' or ''Prūsija'' was a German state on the southeast coast of the Baltic Sea. It formed the German Empire under Prussian rule when it united the German states in 1871. It was ''de facto'' dissolved by an em ...

. According to him, “the carbon monoxide turns into carbonic acid causing deadly deoxidation. ��The cause of the pathophysiological disorders could also be a sudden increase in temperature due to the overoxidation of carbon in the blood”. Of course, Chenot, who "Admits that carbon monoxide plays in the blood the

ame #REDIRECT AME #REDIRECT AME {{redirect category shell, {{R from other capitalisation{{R from ambiguous page ...

{{redirect category shell, {{R from other capitalisation{{R from ambiguous page ...

role of reducing body as in metallurgy", can only offer a partial explanation since it does not carefully analyze the physiological aspects. Despite limitations of his analysis, Chenot remains among the first to propose a chemical theory of the mechanism of poisoning by this gas.

Miscellaneous

Adrien Chenot also campaigned for the repeal of the law relating to the establishment of major railway lines in France .

Publications and works

Adrien Chenot publications

References

{{DEFAULTSORT:Chenot, Adrien 1855 deaths French engineers 1803 births