Apparatus and process for the production of fire-refined blister copper

Abstract

Fire-refined blister copper is produced from copper concentrate by a process comprising: A. melting and oxidizing the copper concentrate in a smelting furnace to produce molten matte and slag, and to separate one from the other; B. removing the molten matte from the smelting furnace; C. solidifying the molten matte; D. injecting the solidified matte into a converting furnace in which the matte is converted to blister copper and slag; and E. transfering the blister copper from the converting furnace to an anode furnace to produce fire-refined blister copper. After the fire-refined blister copper is produced in the anode furnace, it is typically transferred to an anode casting wheel on which it is converted to copper anodes suitable for subsequent electrolytic refining to cathode copper.

Description

FIELD OF THE INVENTIONThis invention relates to the pyrometallurgy of copper. In one aspect, this invention relates to the smelting of copper concentrates to produce fire-refined blister copper while in another aspect, this invention relates to a copper smelting apparatus and process that allows the uncoupling, in both space and time, of the smelting and converting furnaces and their respective operations. In another aspect, this invention relates to a process for the smelting of copper that is both energy efficient and that has a very low impact on the environment.BACKGROUNDCopper smelting involves two primary process steps: (1) smelting to produce copper matte, and (2) converting to produce copper metal. While smelting technology has changed dramatically in the last thirty years, converting has changed little since Messrs. Peirce and Smith developed the side blown converter in the early 1900's. Although the Peirce-Smith converter has proven its worth over time, its design does not...

AI Technical Summary

Benefits of technology

In a preferred embodiment of this invention, the smelting and converting furnaces are flash furnaces, and the converting step is solid matte oxygen converting as described in U.S. Pat. No. 4,416,690. In this and other embodiments, the molten matte is transferred from the smelting furnace to a solidification apparatus, e.g. granulating or casting equipment, and the solidified product is either transferred to the converting furnace, with or without prior size reduction, or is stored. This uncoupling of the smelting and converting furnaces allows virtually complete flexibility in scheduling their respective uses, and allows one to be physically remote (e.g. off-site) from the other.

The process of this invention is environmentally efficient. In certain embodiments, copper concentrate can be converted to fire-refined blister copper with capture of at least about 98 percent, preferably at least about 99 percent, of the input sulfur, and sulfur dioxide emissions can be reduced to less than about 5, preferably less than about 3, kilograms per metric ton of copper produced. By "capture" is meant that the input sulfur, i.e. the sulfur value of the copper concentrate, is retained in the process or leaves the process as a product or by-product, e.g. a metal sulfide, sulfuric acid, etc. In addition, particulate and acid mist emissions are significantly reduced.

Problems solved by technology

Although the Peirce-Smith converter has proven its worth over time, its design does not lend itself well to compliance with the ever increasingly stringent environmental requirements that copper producers must meet.

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