Top submerged injecting lances

1. 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; 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,

wherein

the lower end of the inner pipe is set back from the lower end of the outer pipe so that a mixing chamber is defined between those ends; and

the lance is adapted for suspension from an installation that is operable to raise or lower the lance as a whole relative to a TSL reactor and enables relative longitudinal movement between the inner and outer pipes, the relative positions of the inner and outer pipes being longitudinally adjustable to enable the required set level or the length of the 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,

further including a drive system by which the relative longitudinal movement between the inner and outer pipes is generated,

and wherein a helical vane or flow shaping device is provided between the outer pipe and the inner pipe or, where the lance has at least three substantially concentric pipes, between the outer pipe or a next innermost pipe between the outer pipe and the inner pipe.

2. The lance of claim 1 , wherein the lance has two pipes, with a vane connected at one of opposite longitudinal edges to the outer surface of the inner pipe and its other longitudinal edge adjacent to the inner surface of the outer pipe.

3. The lance of claim 1 , wherein the lance has at least three pipes, with a vane connected at one of opposite longitudinal edges to the outer surface of a pipe next innermost of the outer pipe, with its other longitudinal edge adjacent to the inner surface of the outer pipe.

4. The lance of claim 3 , wherein the pipes other than the outer pipe are longitudinally fixed relative to each other.

5. The lance of claim 3 , wherein the pipes other than the outer pipe are longitudinally movable relative to each other.

6. The lance of claim 1 , wherein the lance enables relative longitudinal movement between the inner and outer pipes by the installation lowering a mounting by which the lance as a whole is supported as the inner pipe is raised relative to the mountings.

7. The lance of claim 1 , wherein the lance enables relative longitudinal movement between the inner and outer pipes by the inner pipe being lowered while the outer pipe is held stationary.

8. The lance of claim 1 , wherein the drive system is operable to generate relative movement at a substantially constant predetermined rate.

9. The lance of claim 1 , wherein the drive is variable to accommodate a variation in operating conditions in which the lance is used.

10. The lance of claim 1 , wherein the drive system is adjustable manually.

11. The lance of claim 1 , wherein the drive system is adjustable by remote control.

12. The lance of claim 1 , wherein the lance includes or has an associated sensor able to monitor at least one parameter of a pyrometallurgical operation and to provide an output by which the drive system is adjustable.