| 摘要 |
<p>960,941. Ingot moulds; mould and core materials. FOSECO TRADING A.G. March 21, 1963 [April 11, 1962], No. 14047/62. Heading B3F. [Also in Division B5] In a method of producing linings or hot tops for ingot moulds, a pulp slurry is made from a fibrous organic material and other solid refractory ingredients, e.g. waste newsprint, silica flow, asbestos, quartz, or calcined dolomite, mixed with excess of water, a thermosetting binding agent, e.g. both a urea formaldehyde and a phenol formaldehyde resin, being added to the aqueous slurry which is then charged into a moulding vessel having a wall (e.g. of wire mesh) which is permeable only to the liquid medium, the binding agent being precipitated from the slurry either before or after charging to the moulding vessel, the liquid medium then passing through the permeable wall leaving behind a compacted mass of the solid constitents of the slurry which is subsequently heated to dry them and to cure the binding agent. The binding agent is precipitated by adjusting the pH of the slurry, e.g. to pH5 by the addition of a sufficient quantity of sodium or potassium bisulphate. Air pressure may be applied to the slurry to aid the liquid medium to pass through the moulding vessel.</p> |
