<?xml version='1.0' encoding='utf-8'?>
<oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd">
  <dc:contributor>F. E. Senftle</dc:contributor>
  <dc:contributor>Corrine Alexander</dc:contributor>
  <dc:contributor>F.T. Dulong</dc:contributor>
  <dc:contributor>R.B. LaCount</dc:contributor>
  <dc:contributor>S. Friedman</dc:contributor>
  <dc:creator>A. N. Thorpe</dc:creator>
  <dc:date>1987</dc:date>
  <dc:description>&lt;p&gt;&lt;span&gt;Pyrite (FeS&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;) inclusions in coal, when heated in an oxygen deficient atmosphere (approximately 1% oxygen), become coated with magnetic Fe&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;O&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;due to oxidation. Most of the FeS&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;can thus be removed from the coal by magnetic separation to reduce the sulphur concentration. The oxidation products have been studied in greater detail by measuring the SO&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;and O&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;in the effluent gas during the heating process and by performing further magnetic measurements. At 582 K, the pyrite surface was oxidized to FeSO&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;. Significant oxidation of FeSO&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;and FeS&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;to Fe&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;O&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;was observed starting at 677 K. At about 681 K, the Fe&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;O&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;is further oxidized to α-Fe&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;O&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;. At 681 K, under isothermal conditions, the oxidation is impeded by the α-Fe&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;O&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;&amp;nbsp;formed on the surfaces of the grains. If the temperature is rapidly increased, the oxygen penetrates the α-Fe&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;O&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;&amp;nbsp;veneer to the FeS&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;&amp;nbsp;core of the pyrite grains and oxidizes essentially the whole pyrite mass to Fe&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;O&lt;/span&gt;&lt;sub&gt;4&lt;/sub&gt;&lt;span&gt;&amp;nbsp;before α-Fe&lt;/span&gt;&lt;sub&gt;2&lt;/sub&gt;&lt;span&gt;O&lt;/span&gt;&lt;sub&gt;3&lt;/sub&gt;&lt;span&gt;&amp;nbsp;can be formed.&lt;/span&gt;&lt;/p&gt;</dc:description>
  <dc:format>application/pdf</dc:format>
  <dc:identifier>10.1016/0016-2361(87)90232-8</dc:identifier>
  <dc:language>en</dc:language>
  <dc:publisher>Elsevier</dc:publisher>
  <dc:title>Oxidation of pyrite in an anoxic atmosphere</dc:title>
  <dc:type>article</dc:type>
</oai_dc:dc>