Kinetics of the flash converting of MK (chalcocite) concentrate
- PDF / 1,512,595 Bytes
- 13 Pages / 612 x 792 pts (letter) Page_size
- 29 Downloads / 226 Views
I.
INTRODUCTION
F L A S H oxidation for the treatment of MK (chalcocitel concentrates was examined by Inco Ltd. as a potential alternative to Pierce-Smith converting in the recent process flow sheet revisions at the Copper Cliff operations. The copper and nickel production process at the Inco Copper Cliff smelter as of 1991 treated the metal sulfides individually after an initial separation of the bulk concentrate by flotation5 ~ The nickel concentrate, containing significant levels of copper, was smelted progressively in multiplehearth roasters, reverberatory furnaces, and Pierce-Smith converters. The product, a Bessemer matte, was slow cooled to promote phase separation and then crushed and ground. The matte was then processed by flotation, again to separate copper and nickel sulfides. The resultant copper sulfide fraction (MK concentrate) was flash smelted to semiblister copper and finally oxidized in Pierce-Smith converters. Revisions to the process were examined in order to meet more stringent regttlations on sulfur dioxide gas emissions. One such process revision was proposed by Landolt et al.l'l which called for elimination of the initial copper-nickel separation by flotation; rather, the bulk concentrate would be flash smelted and converted to Bessemer matte. After subsequent separation, the nickel concentrate would be treated as before, but the MK concentrate would be flash converted to semiblister copper containing approximately 1 pet sulfur, and finally reduced in a novel top blown finishing converter developed by Inco. Flash converting was viewed as a potentially preferable process, because the off-gas of a flash reactor has a more consistent and substantially more enriched SO, content due to continuous operation and the use of tonnage oxygen,
G.J. MORGAN. Graduate Student. The Centre for Metallurgical Process Engineering, and LK. BRIMACOMBE, Alcan Chair in Materials Process Engineering, and Director, The Centre for Metallurgical Process Engineering, are with The University of British Columbia, Vancouver. BC, Canada VrT IZ4. Manuscript submitted September 7, 1995. METAI.LURGICAL AND MATERIALS TRANSACTIONS B
thereby facilitating sulfur dioxide scrubbing. In contrast, Pierce-Smith converters run on a batch cycle with air or oxygen-enriched air as the oxidant. The major problem encountered in applying flash smelting technology to the converting of chalcocite is the generation of considerable amounts of fine dust52-5~ The dust must be separated from the reactor off-gas prior to sulfur dioxide scrubbing, requiring an additional process step and handling equipment. Therefore, if excessive dust generation rates cannot be avoided, there is a significant increase in the capital cost of the process plant. Indeed, the problem of dust generation led to the abandonment of flash converting in favor of submerged injection of chalcocite and oxygen in a conventional Pierce-Smith converter, the process subsequently adopted at Inco Copper Cliff. The work described in this article was undertaken to determine the kineti
Data Loading...
