Martin process

Martin process [ˈmɑː(r)tın] s METALL (Siemens-)Martin-Prozess m

(met) process Martin

technical martinanje

• мартеновский процесс

• сименс-мартеновский процесс

proces martenowski wytapiania stali

SUBJECT AREA: Metallurgy

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His father Emile owned an iron-and steelworks at Sireuil, near Angoulême, and, through this, Pierre became interested in improving the steelmaking process. In England, C.W. Siemens had developed the regenerative principle of waste-heat recovery that produced a much higher furnace temperature. In 1863, the Martins applied this process in an open-hearth furnace built under licence from Siemens, with the aid of his engineers. They melted a mixture of pig-and wrought iron to produce steel with the required carbon content. Martin exhibited the product at the Paris Exhibition of 1867 and was awarded a gold medal. The open-hearth process was for a long time known as the Siemens-Martin process, but Martin did not share in the profits which others gained from its successful adoption. He had difficulty in obtaining patent rights as it was claimed that the principles of the process were already known and in use. The costs of litigation brought Martin to the brink of poverty, from which relief came only late in life, when in 1907 the Comité des Forges de France opened a subscription for him that was generously supported. A week before his death, the Iron and Steel Institute of London bestowed on him their Bessemer gold medal.

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SUBJECT AREA: Textiles

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The object of condensing, the last process in carding, is to obtain a roving, or slightly twisted yarn which is the same thickness and weight throughout its length. In a tape condenser, the web of fibres from the last swift of the carder is divided into the requisite number of ribbons, which are supported on tapes before being rubbed into round rovings and wound onto bobbins ready for spinning.

It was Martin who introduced in 1861 what became the most common type of condenser on the European continent. It divided the web by a combined tearing and cutting action between leather tapes and a pair of rigid rollers. As its division of the web was more minute than with earlier machines, its product was more suitable for fine yarns, so it was accepted rapidly in Belgium and France but much more slowly in England and the United States.

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SUBJECT AREA: Metallurgy

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The son of a Congregationalist minister, Hall was educated at Oberlin College. There he was instructed in chemistry by Professor F.F.Jewett, a former student of the German chemist Friedrich Wöhler, who encouraged Hall to believe that there was a need for a cheap process for the manufacture of aluminium. After graduating in 1885, Hall set to work in his private laboratory exploring the method of fused salt electrolysis. On Wednesday 10 February 1886 he found that alumina dissolved in fused cryolite "like sugar in water", and that the bath so produced was a good conductor of electricity. He contained the solution in a pure graphite crucible which also acted as an efficient cathode, and by 16 February 1886 had produced the first globules of metallic aluminium. With two backers, Hall was able to complete his experiments and establish a small pilot plant in Boston, but they withdrew after the US Patent Examiners reported that Hall's invention had been anticipated by a French patent, filed by Paul Toussaint Héroult in April 1886. Although Hall had not filed until July 1886, he was permitted to testify that his invention had been completed by 16 February 1886 and on 2 April 1889 he was granted a seventeen-year monopoly in the United States. Hall now had the support of Captain A.E. Hunt of the Pittsburgh Testing Institute who provided the capital for establishing the Pittsburgh Reduction Company, which by 1889 was selling aluminium at $1 per pound compared to the $15 for sodium-reduced aluminium. Further capital was provided by the banker Andrew Mellon (1855–1937). Hall then turned his attention to Britain and began negotiations with Johnson Matthey, who provided land on a site at Patricroft near Manchester. Here the Aluminium Syndicate, owned by the Pittsburgh Reduction Company, began to produce aluminium in July 1890. By this time the validity of Hall's patent was being strongly contested by Héroult and also by the Cowles brothers, who attempted to operate the Hall process in the United States. Hall successfully sued them for infringement, and was confirmed in his patent rights by the celebrated ruling in 1893 of William Howard Taft, subsequently President of the USA. In 1895 Hall's company changed its name to the Pittsburgh Aluminium Company and moved to Niagara Falls, where cheap electrical power was available. In 1903 a legal compromise ended the litigation between the Hall and Héroult organizations. The American rights in the invention were awarded to Hall, and the European to Héroult. The Pittsburgh Aluminium Company became the Aluminium Company of America on 1 January 1907. On his death he left his estate, worth about $45 million, for the advancement of education.

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open-hearth process HÜTT/WALZ Siemens-Martin-Verfahren n

Siemens-Martin-Verfahren n HÜTT/WALZ open-hearth process

n < metall> ■ open-hearth process

< metal> ■ Siemens-Martin-Verfahren n

proses siemens martin

procedimiento al hogar abierto, procedimiento Siemens-Martin para elaborar acero.