Operational Challenges and Lessons Learnt at Xinli Nonferrous Co Ltd’s Ilmenite Smelter

摘要

Bateman Engineering provided process technology and engineering design to China YunnanrnMetallurgical Company (CYMCO) for a 30 MW DC furnace for the production of high-grade titaniumrndioxide slag.rnFollowing the successful commissioning of the furnace during the latter part of 2009 and thernfi rst quarter of 2010, a period of adverse circumstances resulted in having to operate the furnacernwithout feed and at a low power input for a period of time. When normal feed resumed, a layerrnof solid material was detected on the slag-iron interface during sounding measurements. Therncondition of the iron was also signifi cantly altered. The iron temperature was much higher thanrnthe design value, but the carbon content had decreased to such an extent that a large amount ofrniron solidifi ed in the furnace, which made iron tapping very challenging. The slag temperature wasrnincreased in order to melt the solidifi ed iron. However, severe sidewall damage resulted, whichrnfi nally led to a burn-through.rnA number of samples were taken from the slag that remained in the furnace. These samples werernanalysed to determine the chemistry and phase profi le throughout the slag bath. The mechanisms ofrnformation of the high melting-temperature phase on the slag-iron interface are discussed, as well asrnprocedures that can be applied to prevent a recurrence of this phenomenon. Some recommendationsrnare made for instances when furnace feeding is interrupted for an indeterminate period.