Calcination is a process in which ore is heated in the absence of air or air might be supplied in limited quantity. Roasting involves heating of ore lower than its melting point in the presence of air or oxygen. Calcination involves thermal decomposition of carbonate ores.<\/p>\n\n\n\n
Smelting \u2013 it involves heating the roasted or calcined ore (metal oxide) to a high temperature with a suitable reducing agent. The crude metal is obtained in its molten state. Aluminothermic reaction \u2013 also known as the Goldschmidt reaction is a highly exothermic reaction in which metal oxides usually of Fe and Cr are heated to a high temperature with aluminium. Electrolytic reduction:<\/p>\n\n\n\n 1. Down\u2019s process: Molten NaCl is electrolysed in a special apparatus.<\/p>\n\n\n\n At the cathode <\/strong>(reduction): At the anode<\/strong> (oxidation): 2. Hall\u2019s process: Mixture of molten alumina and a fluoride solvent usually cryolite, (Na3<\/sub>AlF6<\/sub>) is electrolysed.<\/p>\n\n\n\n At the cathode <\/strong>(reduction): At the anode <\/strong>(oxidation): The metals at the top of the reactivity series are highly reactive. They cannot be obtained from their compounds by heating with carbon, because these metals have more affinity for oxygen than carbon. Hence, for the extraction of such metals electrolytic reduction method is used.<\/p>\n","protected":false},"excerpt":{"rendered":" Calcination is a process in which ore is heated in the absence of air or air might be supplied in limited quantity. Roasting involves heating of ore lower than its melting point in the presence of air or oxygen. Calcination involves thermal decomposition of carbonate ores. Smelting \u2013 it involves heating the roasted or calcined ore […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[637],"tags":[],"_links":{"self":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/posts\/5464"}],"collection":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/comments?post=5464"}],"version-history":[{"count":0,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/posts\/5464\/revisions"}],"wp:attachment":[{"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/media?parent=5464"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/categories?post=5464"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mudassirbackup.infinitycodestudio.com\/index.php\/wp-json\/wp\/v2\/tags?post=5464"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
Fe2<\/sub>O3<\/sub>+3C(coke)\u21922Fe+3CO2<\/sub><\/p>\n\n\n\n
Fe2<\/sub>O3<\/sub>+2Al\u2192Al2<\/sub>O3<\/sub>+2Fe+heat
Cr2<\/sub>O3<\/sub>+2Al\u2192Al2<\/sub>O3<\/sub>+2Cr+heat<\/p>\n\n\n\nExtraction of Metals Towards the Top of the Reactivity Series<\/h3>\n\n\n\n
Na+<\/sup>(molten)+e\u2212<\/sup>\u2192Na(s)
Metal is deposited.<\/p>\n\n\n\n
2Cl\u2212<\/sup>(molten)\u2192Cl2<\/sub>(g)+2e\u2013<\/sup>
Chlorine gas is liberated.<\/p>\n\n\n\n
2Al3+<\/sup>+6e\u2013<\/sup>\u2192 2Al(s)
Metal is deposited.<\/p>\n\n\n\n
6O2<\/sub>\u2013 <\/sup>\u2192 3O2<\/sub>(g)+12e\u2013<\/sup>
Oxygen gas is liberated.<\/p>\n\n\n\n