Preliminary study about the heat decomposition of manganese ores typologies from Carajas

• Published in: Tecnologia em Metalurgia, Materiais e Mineracao Vol. 20110718; pp. 420 - 425
• Main Authors: Reis, Erica Linhares, De Faria, Geraldo Lucio, Araujo, Fernando Gabriel Da Silva, Tenorio, Jorge Alberto Soares, Junior, Nelson Janotti
• Format: Journal Article
• Language: English
• Published: 01.01.2011
• Subjects: Brazil; Decomposition; Kaolinite; Manganese ores; Minerals; Moisture; Phases; Weight loss
• ISSN: 2176-1515

This work presents a preliminary investigation about the heat decomposition of the main mineralogical constituents of three different manganese ores typologies. The studied manganese ores typologies are from the region of Carajas, in the north of Brazil. Thermogravimetrical analysis (TGA) identified the weight losses. For temperatures below 280 degree C the weight decrease were associated to the moisture elimination. This was observed for all typologies. For temperatures around 400 degree C the weight loss is related to the decomposition of todorokite nsutita, kaolinite and goethite, which are hydrated mineral phases. For temperatures around 600 degree C, the weight decrease is associated to the cryptomelane decomposition to Mn(2)O(3). The nsutite and the todorokite products decompositions also decompose to Mn(2)O(3). For temperatures between 800 degree C and 1000 degree C, the previous formed Mn(2)O(3) begins to decompose Mn3O4. At temperatures above 1000 degree C the tetragonal Mn(3)O(4) changes to cubic gamma -Mn(3)O(4).