Technologies for determining matte and slag levels in copper smelting and other metallurgical furnaces

The production of copper is typically done through the smelting of concentrate. During the primary smelting process,the concentrate is typically processed into a higher purity matte stream and a waste slag stream containing various impurities. The matte and slag phases separate via density differences. Understanding the height of each layer in the furnace is critical for process control, furnace integrity, and operational reasons.

The most basic approaches for level measurement are mass balance calculations and the use of sounding rods. However, such approaches have accuracy and safety-related drawbacks. For example, the physical inspection of sounding bars to determine levels is prone to human error and may change from operator to operator. This practice also may depend on operators on the furnace roof unless automated. Further problems arise from the sometimes fuzzy nature of the interface between furnace layers.

Several more advanced technologies are available to determine matte and slag levels in operating furnaces. In this paper, the commercially available level measurement technologies are presented. In addition, new developments and approaches in level measurement technologies are introduced.