Top submerged injecting lances

A lance, for conducting a pyrometallurgical operation by top submerged lancing (TSL) injection, wherein the lance has a plurality of substantially concentric pipes including inner and outer pipes and, optionally, at least one pipe between the inner and outer pipes;

• the lower end of the inner or the inner pipe and at least a next outermost pipe is set substantially at a required level relative to the lower end of the outer pipe required for the pyrometallurgical operation;
• wherein the relative positions of the inner and outer pipes are longitudinally adjustable to enable the required set level or the length of a mixing chamber between the lower ends of the inner and outer pipes to be maintained during a period of use to compensate for the lower end of the outer pipe wearing and burning back;
• and wherein the lance defines at least two passages, including an annular passage defined between two of the pipes and a passage defined by the inner pipe, whereby the lance enables fuel/reductant and oxygen-containing gas to be injected separately through the lance so as to mix at the outlet ends of the inner and outer pipes and generate a combustion zone within a slag phase during top submerged injection during the pyrometallurgical operation, while maintaining a protective coating of solidified slag over the outer surface of the outer pipe over at least a lower part of the length of the lance submerged in molten slag during the operation.