Abstract: After the start of supply of a purge gas to a storage container, a supply rate control unit performs supply rate increase control to gradually increase the supply rate such that the supply rate reaches a first flow rate, and after the supply rate reaches the first flow rate, the supply rate control unit performs supply rate maintenance control to maintain the supply rate at the first flow rate or larger. A discharge rate control unit keeps a discharge rate at zero while the supply rate increase control is being executed, and when the supply rate reaches the first flow rate, the discharge rate control unit performs discharge rate maintenance control to maintain the discharge rate at or below a second flow rate smaller than the first flow rate.

Abstract: A transfer machine raises and lowers a support portion in a transfer operation between a lower set position that is set below a placement portion of a transfer location subject to the transfer operation, and an upper set position that is set above the placement portion, and a control device changes setting of at least one of the lower set position and the upper set position to set a different raising/lowering range of the support portion that covers a range from the lower set position to the upper set position, between a case where an article is transferred to the transfer location provided in a storage/retrieval section, and a case where the article is transferred to the transfer location provided in accommodation sections.

Abstract: A method of regenerating molten slag remaining in a furnace or converter or the like after tapping of steel, by adding solid carbon and flux to the slag, blowing oxygen into the slag, heating to a temperature of more than 1500.degree. C and agitating. The regenerated slag can be controlled in composition to be most suitable for such ultimate uses as lime, cement, etc.

Abstract: In a steel making process with an oxygen top-blown converter when a certain inclining angle (.theta.) is given within a range of 0<.theta..ltoreq.15.degree. to normal axis of an oxygen blow lance being supported at an upper portion of the lance and a certain number of rotation (.nu.) is given within the range of 0<.nu..ltoreq.15 rpm to the lance, the blow of oxygen is possible to be properly used as the refining reactions are advanced without any delay of slagging reaction and any stagnation of non-slagging lime during blowing.