Lance unblocking method and apparatus

A method of removing a blockage in a solids injection lance under normal operating conditions of a direct smelting vessel containing a bath of molten metal and slag, wherein the solids injection lance extends into the direct smelting vessel and has an outlet end that is submerged in the molten metal and slag and has a single inlet coupled to a section of supply line that conveys carrier gas and solid feed material to the solids injection lance, the section of supply line is upstream and co-axial with the solids injection lance, the method comprising the following sequential steps:

• (a) depressurising the solids injection lance and the supply line section upstream of the blockage;
• (b) advancing a blockage-removing tool through the supply line section and through the solids injection lance to an upstream side of the blockage;
• (c) re-pressurising the solids injection lance and the supply line section to create elevated gas pressure conditions;
• and
• (d) operating the tool to remove the blockage, wherein the tool is operated in reciprocal movement co-axially within the solids injection lance such that solid feed material and carrier gas are able to flow through the solids injection lance and into the direct smelting vessel, while maintaining the elevated gas pressure conditions in the solids injections lance and upstream of the blockage;
• wherein the elevated gas pressure conditions are provided by ceasing supply of the carrier gas and then supplying a pressurised purge gas to the solids injection lance upstream of the blockage such that, upon removal of the blockage, the purge gas flows into the direct smelting vessel thereby preventing slag from entering the outlet end of the solids injection lance;
• and
• (e) retracting the tool from the solids injection lance and the supply line section.