摘要 |
<p>Casting of high temp. refractory blocks for furnace linings etc. is effected through a funnel on top of a water cooled collapsible metal mould. The melt has a compn. which gives off gases during solidification. During the casting operation a fixed proportion of broken up solid refractory of the same compn. as the melt is introduced into the casting jet and mixed with the melt. The addition of the solid is carried out as long as the mould proper is being filled up. The cast block is removed from the mould whilst still hot, when only the surface has solidified and subjected to a controlled rate cooling cycle outside the mould. The process is intended particularly for MgO refractory pieces containing some Cr2O3. Both the gas formation on solidification and addition of solid material even out the cooling of the block after casting and prevent the formation of a central pipe type core hole.</p> |