An alumina-based filling sand for sliding nozzle comprising at least 50 wt % of mixed sand including 20 to 90 vol % of alumina sand and 80 to 10 vol % of silica sand, wherein the alumina sand has surface irregularities of 1.3 or less and comprises 50 wt % or more of an Al.sub.2O.sub.3 component.

An alumina-based filling sand for sliding nozzle comprising at least 50 wt % of mixed sand including 20 to 90 vol % of alumina sand and 80 to 10 vol % of silica sand, wherein the alumina sand has surface irregularities of 1.3 or less and comprises 50 wt % or more of an Al.sub.2O.sub.3 component.

A mounting device capable of smoothly mounting a drive unit being in a hanging state to a sliding nozzle device, using a manipulator. The mounting device is mounted to a distal end of a manipulator to mount a drive unit whose upper end is connected to a suspending device, to a holder of a sliding nozzle device. The mounting device includes: a holding part for holding an upper portion or central portion (to-be-held plate) of the drive unit; and a contact part which is contactable with a lower portion (to-be-contacted part) of the drive unit when mounting the drive unit to the holder.

A slide closure for a vessel containing molten metal has a slider housing (12), a slide unit guided longitudinally therein, with a slide rod (13), a holder (15) on the slider housing (12) as well as a linear actuator (20) which can be fastened in this holder (15) with a drive rod (20) which can be coupled to the slide rod (13). The linear actuator (20) can be slid into the holder (15) on the slider housing (12), preferably transverse to its direction of adjustment, and can be removed from same and can be locked in the holder (15). At least one locking means (25, 30) is fastened to each of the linear actuator (20) and the holder (15), which locking means are developed to interact such that the linear actuator (20) locks automatically after or during being pushed into the holder (15). A permanently secure fastening of the linear actuator in the holder thus results.