Experimental studies on particle temperatures in copper flash smelting

摘要

Particle temperature is an essential parameter governing the fundamental chemical and physical processes in the flash smelting process. The objective of this work was to experimentally study temperatures and sizes of reacting copper concentrate particles in a flash smelting process. The measurements were made in a laboratory-scale laminar flow reactor. Pulverized chalcopyrite particles were fed into the electrically heated furnace, where they reacted with oxygen. The temperature and size of individual particles were measured with a developed fast two-colour particle pyrometer. In 10 vol-% oxygen concentration the average particle temperature 1430 K was slightly higher than the ambient gas temperature 1273 K. Increasing the oxygen concentration to 20 vol-% increased the average particle temperature to 1690 K. The highest average particle temperatures of 2290 K were detected in a test with 75 vol-% oxygen concentration. In addition to temperatures, the pyrometer enabled the simultaneous size measurement of particles. The results showed that particles differed notably in temperature and size. The most probable reason for that is the large variation of reaction rates of individual particles. The measured particle temperatures were compared with the values predicted by computational fluid dynamics model for flash smelting furnace. The measurements verified the validity of the model.