The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
May. 18, 1976
Filed:
Sep. 18, 1974
Simon Otto Fekete, Arvada, CO (US);
Colin Bruce MacKenzie, Falconbridge, Ontario, CA;
Philip George Thornhill, Thornhill, Ontario, CA;
Edward Howard Coulter, Unionville, Ontario, CA;
Kenneth Leslie Agnew, Falconbridge, Ontario, CA;
Other;
Abstract
An improved method for agglomerative fluid bed roasting of metal sulphide particles. The sulphide particles are fed as an aqueous slurry through the freeboard of the roaster onto the surface of a bed of roasted calcine agglomerate particles fluidized by a free oxygen-bearing gas. Slurry water is evaporated in the bed and the sulphides are roasted therein. The feed rates of sulphide, water and free oxygen-containing gas are controlled to ensure temperatures in the roaster such that fusion occurs during roasting and agglomerated calcine particles are formed with regular, rounded surfaces. Calcine particles small enough to become entrained in the roaster off-gases are readily disengaged therefrom in cyclones to provide substantially dust-free SO.sub.2 -bearing gas. A preferred practice of the method is feeding substantially the stoichiometric amount of free oxygen to convert the sulphide to SO.sub.2 and metal oxide, thereby producing on the one hand a roasted oxide calcine substantially devoid of sulphur and on the other hand an SO.sub.2 -bearing gas substantially devoid of free oxygen. The method is particularly advantageous in the roasting of pyrrhotite concentrates and other sulphide concentrates containing pyrrhotite such as those derived from the nickel-copper ores of the Sudbury Basin.