Download or read book Valorisation de r sidus miniers riches en fer written by Abdoulaye Maihatchi Ahamed and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'augmentation de la démographie mondiale (de 2,5 milliards en 1950 à 10 milliards d'habitants en 2050 selon l'Organisation des Nations Unies) entraine une augmentation des besoins en métaux. Ces métaux proviennent des mines, mais leur production à partir des minerais engendre d'énormes quantités de résidus. Ces derniers occupent de grands espaces de stockage et contiennent encore des métaux qui peuvent être extraits. La valorisation de ces résidus permettrait non seulement de réduire leurs volumes et leurs empreintes écologiques, mais aussi et surtout de produire des métaux à forte valeur ajoutée pour répondre aux besoins des nouvelles technologies. Deux types de résidus riches en fer ont été étudiés dans ce travail afin d'extraire le fer et le zinc qu'ils contiennent par électrodéposition : les boues rouges et la jarosite. Dans le premier cas, il s'agit des résidus provenant de la production de l'alumine à partir du minerai de bauxite par le procédé Bayer (procédé alcalin). Le deuxième type de résidu, la jarosite, provient de la production du zinc par le procédé « jarosite » en milieu acide. Pour ce faire, deux approches expérimentales ont été mises en place. Une électrodéposition directe dans le cas de boues rouges : les échantillons sont directement mis en suspension dans une solution de NaOH 12,5 mol/L et le fer (sous forme d'hématite et/ou de goethite) est électrodéposé sur une cathode en graphite à une température de 110°C. Pour le cas de la jarosite, une démarche différente a été mise en place : (i) une lixiviation de la jarosite en milieu acide sulfurique, (ii) une lixiviation de blende pour réduire le fer ferrique en fer ferreux et enrichir le bain en zinc, (iii) une cémentation du cuivre par une poudre de zinc et enfin (iv) une étape d'électrodéposition d'alliage fer-zinc. Dans les deux cas de résidus, plusieurs paramètres opératoires ont été testés afin d'optimiser les rendements de lixiviation, de cémentation, la qualité des dépôts et les rendements faradiques. En ce qui concerne les boues rouges, les meilleurs rendements faradiques (72%) ont été obtenus pour un ratio solide/liquide de 1/3 (g/mL), une concentration en NaOH de 12,5 mol/L, une densité de courant de 41 A/m2 et une température de 110°C. Les dépôts du fer électrolytique, analysés par ICP-AES, DRX, MEB/EDX, présentent une pureté supérieure à 97% massique en fer. Pour la jarosite, les meilleurs rendements de lixiviation (en zinc et en fer étaient de 73% et 70% respectivement) ont été obtenus pour une concentration d'acide sulfurique égale à 1,5 M, un rapport solide/liquide 1/10 (g/mL) et une température de 80°C pendant 7 heures. Les essais d'électrodéposition ont permis de produire des alliages zinc -fer à différentes teneurs en fer. Les rendements faradiques obtenus dans les conditions optimales (densité de courant de 800 A/m2 et une température de 20°C) étaient de l'ordre de 89%. Les résultats obtenus dans cette étude confirment la faisabilité technique d'électrodéposition du fer et d'alliage fer-zinc à partir des matrices complexe. Cela ouvre une nouvelle alternative à la valorisation des résidus miniers par la technique d'électrodéposition des métaux.
Download or read book The Boundaries of the West African Craton written by Nasser Ennih and published by Geological Society of London. This book was released on 2008 with total page 552 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Disintegration and Integration in East central Europe 1919 Post 1989 Ver ffentlichungen Der Historiker verbindungsgruppe Bei Der Kommission Der EG written by Nicolae Paun and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The End of Empires written by Michael Gehler and published by Springer Nature. This book was released on 2022-11-21 with total page 737 pages. Available in PDF, EPUB and Kindle. Book excerpt: The articles of this comprehensive edited volume offer a multidisciplinary, global and comparative approach to the history of empires. They analyze their ends over a long spectrum of humankind’s history, ranging from Ancient History through Modern Times. As the main guiding question, every author of this volume scrutinizes the reasons for the decline, the erosion, and the implosion of individual empires. All contributions locate and highlight different factors that triggered or at least supported the ending or the implosion of empires. This overall question makes all the contributions to this volume comparable and allows to detect similarities, differences as well as inconsistencies of historical processes.
Download or read book Experiencing Europe written by Wilfried Loth and published by Nomos Verlagsgesellschaft. This book was released on 2009 with total page 376 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book discusses how the EC/EU changed from its beginnings, and in which respect the present situation is different from the past. Which trends of evolution can be observed, and which factors may influence the future evolution? In this volume, 19 historians from seven countries, all of them well known experts of the field, are balancing the different aspects of the European experience. Based on broad archival research the volume offers a comprehensive look on the history of European integration and a discussion of the present situation and possible developments in the light of this balance. Experiencing Europe is seen as a response to the challenges Europeans have to meet in the 20th and 21st centuries." --Book Jacket.
Download or read book The Marshall Plan Today written by John Agnew and published by Psychology Press. This book was released on 2004 with total page 310 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book goes beyond diplomatic history to place the Marshall Plan in the context of both the political economy of late 20th century Europe and the impact of American models of business and government that came with the Plan.
Download or read book The Hungarian Peace Treaty written by Great Britain. Parliament. House of Lords and published by . This book was released on 1921 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Italy and the Wider World written by R.J.B. Bosworth and published by Routledge. This book was released on 2013-01-11 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Richard Bosworth's overview of Italy's role in European and world politics from 1860 to 1960 is lively and iconclastic. Based on a combination of primary research and secondary material he examines Italian diplomacy, military power, commerce, culture, tourism and ideology. His account challenges many aspects of current Italian historiography and offers an original vision of the place of Italy in modern history.
Download or read book J zef Pi sudski written by Andrzej Garlicki and published by Routledge. This book was released on 1995 with total page 240 pages. Available in PDF, EPUB and Kindle. Book excerpt: A scholarly study of Polish nationalist, field marshall, president, and finally dictator, J=sef Pilsudski (1867-1935), being an edited and abridged translation of Garlicki's major biography, which went unpublished in its entirety within Poland until 1988, a year before the final collapse of the comm
Download or read book The Turning Point written by Keith Sainsbury and published by Oxford [Oxfordshire] ; New York : Oxford University Press. This book was released on 1986 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: Setting all three summit conferences in the context of other key events in 1943, Sainsbury shows how Teheran was, in many ways, the "turning point" of the war and sheds new light on this often neglected event in recent history.
Download or read book American Debates on Central European Union 1942 1944 written by Józef Łaptos and published by P.I.E-Peter Lang S.A., Editions Scientifiques Internationales. This book was released on 2002 with total page 258 pages. Available in PDF, EPUB and Kindle. Book excerpt: «Fine idea!» was the only response of President F.D. Roosevelt to the Polish Prime Minister Władysław Sikorski's conception of creating a Central and East European federation presented in 1942. Despite the President's sweeping statement, the idea of the federation was given serious consideration by the Advisory Committee of the Department of State. The documents from the National Archives in Washington presented here show that the road to a united Europe could have led through the integration of its Eastern part. This study presents new insights into such issues as the American Advisers' opinion on the role of the federation, the situation on the Eastern front, and how this influenced the fate of the federation.
Download or read book The Byzantine Commonwealth written by Dimitri Obolensky and published by ACLS History E-Book Project. This book was released on 2009-05 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This text is a historical account of the political, diplomatic, ecclesiastical, economic and cultural relations between the Byzantine Empire and the peoples of Eastern Europe. It shows that these nations came to share a common cultural tradition.
Download or read book A History of European Integration written by Walter Lipgens and published by . This book was released on 1982 with total page 723 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Soviet Polish Relations 1917 1921 written by Piotr S. Wandycz and published by . This book was released on 2013-10 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Crises in European Integration written by Ludger Kühnhardt and published by Berghahn Books. This book was released on 2009 with total page 184 pages. Available in PDF, EPUB and Kindle. Book excerpt: "While the major trends in European integration have been well researched and constitute key elements of narratives about its value and purpose, the crises of integration and their effects have not yet attracted sufficient attention. This volume, with original contributions by leading German scholars, suggests that crises of integration should be seen as engines of progress throughout the history of European integration rather than as expressions of failure and regression, a widely held assumption. It therefore throws new light on the current crises in European integration and provides a fascinating panorama of how challenges and responses were guiding the process during its first five decades."--Publisher's website.
Download or read book Romanians and Hungarians from the 9th to the 14th Century written by Ioan Aurel Pop and published by . This book was released on 1996 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Byzantium After Byzantium written by Nicolae Iorga and published by Center For Romanian Studies. This book was released on 2023-01-24 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt: Originally published in French in 1935, the author's formula Byzantium after Byzantium defines several centuries of world history. Iorga points out the great contributions of Byzantine civilization to the Western world, especially during the Renaissance. He demonstrates that Byzantium survived through its people and local autonomies, as well as through its exiles--clerics, scholars, merchants, and political officials. One of the most important expressions of this was found in the Romanian principalities where Greeks from the Phanar district of Istanbul played a major role in Romanian political life, defining an entire period of Romanian history--the Phanariot Period. They continued the Byzantine ideas, aspirations, education, and way of life. All of this allows us to speak of a Byzantium after Byzantium.
