| 摘要 |
<p>1,220,038. Active carbon. F.M.C. CORP. 21 Feb., 1969 [28 Feb., 1968], No. 9405/69. Heading C1A. [Also in Division C7] Iron and active carbon, which latter may be used for water purification, are prepared by mixing iron ore, in the form of powder or an open-pored easily powdered agglomerate thereof, with at least 25% stoichiometric excess of a powdered char of a coal below the rank of anthracite, which char has a CO 2 reactivity at the reduction temperature of over 10% by wt. per hour and heating the mixture at 1775- 1875‹ F. long enough for substantially complete reduction, the iron being recovered in the same particle size range as the ore used. The ore may be high grade haematite or magnetite ore, the reductant may be a char of a bituminous or lignite coal and the CO 2 reactivity thereof may be raised by addition of a metal salt (e.g. Na 2 CO 3 ) during the production thereof. The heating is preferably carried out in a multiple hearth or travelling grate furnace by means of hot gases passed across the path of the moving mixture and the products may be separated mechanically (e.g. by screening for which process the size of the ore and reductant feeds are preferably different) and then magnetically. The char may preferably be made in a series of fluidized beds. An apparatus for determining the CO 2 reactivity of a char is also disclosed.</p> |
