Roasting (metallurgy)

Toasting or roasting referred in metallurgy the treatment of sulfur, antimony and arsenic -containing ores by heating in kilns. This roaster gases such as sulfur dioxide and trioxide arise ( Hüttenrauch ). Further the resulting oxidizing roasting process, metal oxides are subjected to a reducing treatment step.

• 2.1 Applications

• 3.1 applications

Röstreaktionsverfahren

The reducing roasting of metal sulfides to elemental metals ( MenSm → Me) takes place in two steps. First two-thirds of the metal sulfide to be with oxygen (O2) to the reacted metal oxide. In the second step is further heated in the absence of oxygen, thereby reacting the metal sulfide with the remainder of the resulting metal oxide to elemental metal and additional sulfur dioxide.

Applications

Reduction of lead (II) sulfide, to elemental lead:

Reduction of copper ( I) sulphide to elemental copper:

Another example of metal sulfides, the metals are reduced by roasting, is mercury (II ) sulfide.

Roasting reduction

The reduction is caused by carbon dioxide or carbon monoxide.

Applications

By reducing roasting of galena (PbS ) and subsequent reduction of the metal oxide can be obtained pure lead:

• The ore ( galena ) is reacted with oxygen for reaction ( Röstarbeit ):

• Then the newly formed lead (II ) oxide by adding carbon will lead to reduced (reduction work):

Oxidizing roasting

Applications

By the oxidation of pyrite occur iron ( III) oxide and sulfur dioxide. Iron (III ) oxide is processed in blast furnaces for iron and sulfur dioxide for the recovery of sulfuric acid used.

Swell

• Arnold F. Holleman, Nils Wiberg: Textbook of Inorganic Chemistry. 101 Edition, de Gruyter, Berlin, pp. 1321
• Jürgen Falbe and Manfred Regitz (ed.): Rompp compact base Lexikon Chemie. Thieme, Stuttgart / New York 1998, ISBN 3-13-115711-9