US2024308A - Process for causing liquid slags and melts to set in a highly porous fashion - Google Patents

Description

. 17, 1935. c. H. SCHOL PROCESS FOR CAUSING LIQUID SLAGS AND MELTS TO SET IN A HIGHLY POROUS FASHION 2 Sheets-Sheet 1 Filed June 14, 1932 Inventor C'.J', doll/oz 17, 1935. c. H. SCHOL PROCESS FOR CAUSING LIQUID SLAGS AND MELTS TO SET IN A HIGHLY POROUS FASHION Filed June 14; 1932 2 Sheets-Sheet 2 In ventor: 6317f. Jck OZ,

Patented Dec. 17, 1935 UNITED STATES PROCESS FOR CAUSING LIQUID SLAGS AND DIELTS TO SET IN A HIGHLY POROUS FASHION Carl Heinrich Schol, Allendorf (Dillkreis), Germany Application June 14, 1932, Serial No. 617,222 In Germany June 3, 1931 4 Claims.

It is known to swell liquid melts in a troughlike channel of any desired shape to a highly porous mass by bringing the melt into contact with a small quantity of warm or cold water so that it cannot sink in the water but mixes with the small amount of water and as a result is swollen up, the water for the most part evaporating.

It has been found that the use of narrow trough-like swelling channels is attended with many disadvantages. In the first place there is always a certain quantity of fine sand produced, whereas it is desirable to obtain as far as possible yield of coarsely granular highly porous material in the form of large lumps. Further, the melt forms a thicklayer in the narrow trough and since owing to the very high insulating effect and small thermal conductivity of the material this thick layer cannot set rapidly enough in the interior, the individual small cells and pores coalesce to form large gas bubbles, so that an undesirable change takes place in the structure of the sponge-like, finely pored froth slag produced at the commencement of the swelling. Owing to the formation of the large gas bubbles the resulting artificial pumice acquires a mussel-like shell-like appearance, as a result of which both the high insulating eifect and the low specific gravity, as well as the uniform sponge-like appearance, are impaired.

It has now been found that both the yield and the quality of the artificial pumice material can be very considerably improved and a very satisfactory pressure resisting lava froth can be made from many fluid melts, and further that the swollen and still viscous mass can be directly cast in moulds and in this way ready-prepared structural and insulating members of all kinds can be made without the use of any binding means.

This result is secured by the present invention by allowing the liquid melt to spread out in the form of a thin layer on a suitable support.

If a wide plane surface, for example, is providedwith asmall quantity of water or other suitable liquid and the hot liquid melt allowed to fiow thereon, then both the swelling liquid and the liquid melt spread out into a wide and very thin layer over the plane surface, as a result of which the melt is loosened completely, or almost completely, to a highly porous, fine celled, dry mass in the form of large pieces. Since the swelling takes place in only a very thin layer, the individual portions of the melt cannot sink down therein; on the contrary the whole mass must spread itself out over the surface and swell up in the form of large pieces. Not much fine sand can be formed in this process. Since there is no sudden chilling and the set material still malntains a state of red heat for some time, the end product acquires much better toughness and strength than heretofore.

Furthermore very strong heat radiation takes place in the thin wide layer of melt and setting occurs forthwith, as a result of which the coalescence of the fine pores and cells to large bubbles of gas is prevented and the maintenance of the spongy fine-celled structure is ensured.

The material treated in this way is still sufliciently viscous and plastic for it to be conveyed with the aid of a suitable transport device, a

bucket conveyor or the like, and it may be ob- .tained in the form of highly porous large lumps which can then be broken up further in a separate treatment and sorted out into the various granule sizes for marketing.

This still plastic material however'may also be directly cast in moulds and allowed to cool or temper slowly. In order in this way to make, without any further working up and without the use of any binding means, uniform ready-prepared light structural or insulating bodies of all 25 kinds, e. g. blocks, plates, stone-like blocks, planks, boards, tubes, columns and so forth, the aforementioned structural or insulating bodies may also be provided with metal insertions as required, in order considerably to raise the tensile and compressive strength of the resulting moulded shapes, the said insertions being placed in the moulds before or during the casting. Of

course very large light blocks may also be cast.

from the material which can then be sawn or otherwise divided up into the desired shapes.

The porous material made in the aforementioned manner is not hygroscopic and has no capillarity. For many purposes however it is desirable that the material is capable of positively repelling water. This may be brought about by adding some water-repelling substance to the swelling liquid, e. g. a bitumen emulsion (ceresite, heimalol, or the like) so that this material penetrates directly throughout the whole of the porous mass during the froth formation and is held securely therein.

The accompanying drawings show by way of example devices adapted for carrying out the process according to this invention.

Figure 1 is a side elevation of a shoot;

Figure 2 is a front elevation of Figure 1, and Figure 3 is a'front elevation and .part section of a modified form of a device for carrying out the invention using a drum instead of the shoot.

According to Figures 1 and 2 a downwardly bent wide shoot a is used for carrying out the new process; the said shoot widens out from the outflow channel b and is somewhat inclined so that both the water supply through the hollow body 0 as well as the melt issuing from the channel b can spread out in a thin layer. The shoot is capable of swivelling about the point d near the top so that its gradient may be accurately regulated each time, or even in the course of operation, and can be adjusted as desired, e. g. by means of the tie bar 7. Underneath the bent shoot a there is a pan or receptacle e for catching the water; the thin layer of water flowing along with the slag material is intercepted in the receptacle 6 and collected for purposes of re-use. Since the swollen porous plastic mass, still in the incandescent state, falls from the front of the bent shoot a, whilst the remainder of the thin water layer clinging to the wide surface flows downwardly to the collector e, a complete separation of the water from the slag froth takes place, so that the latter can be obtained perfectly dry.

According to Figure 3 a slowly rotating cylinder g is used for carrying out the said process. Both the swelling liquid as well as the melt to be swollen spread out over the wide exterior surface of the cylinder, the result being that the melt is loosened in the same way as described above. Here also the swollen and still viscous mass falls off at the front of the cylinder whilst the rest of the th'n water layer clings to the slowly rotating drum surface and is carried along to the lowest point.

The melt is here again supplied by the outflow channel 1), Whilst the water is distributed as uniformly as possible over the surface of the cylinder by means of a pipe is situated parallel to the axis of the cylinder and having a plurality of openings or nozzles. In order to prevent the water or the melt from flowing 01f at the sides,

each end of the cylinder 9 may be provided with retaining discs, shown in dotted lines in the accompanying drawings.

What I claim is:

1. A method of making a solid porous product from molten slags and melts consisting in applying a thin layer of swelling liquid to a wide smooth even supporting surface and spreading out the hot fluid melt in a thin layer on said layer of swelling liquid.

2. A method of making a solid porous product from molten slags and melts consisting in causing a thin layer of swelling liquid to flow along a wide smooth even supporting surface, feeding the hot fluid melt in a thin layer on to said layer of swelling liquid in the direction of flow of the latter, and separating the-resulting porous semisolid product from the stream of swelling liquid.

3. A method of making a water-repelling solid porous product from molten slags and melts consisting in supplying a swelling liquid in small quantity on to a wide smooth surface said swelling liquid containing a bitumen emulsion and guiding a stream of melt on to the swelling liquid on said surface, whereby said swelling liquid and the liquid melt spread out into a very wide thin layer and the melt becomes loosened to a highly porous fine celled mass without gas bubbles and having water-repelling properties.

4. A method of making a water-repelling solid porous product from molten slags and melts consisting in supplying in small quantity on to a wide smooth surface a swelling liquid containing water-repelling material, and guiding a stream of melt on to the swelling liquid on said surface, whereby said swelling liquid and the liquid melt spread out into a very wide thin layer and the melt is swollen up to a porous product with water-repelling properties, a bitumen emulsion being used as said water-repelling material.

CARL HEINRICH SCHOL.

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