GB2135920A - Apparatus for making cores from fluidized sands in hot boxes - Google Patents

Abstract

An apparatus for making cores from fluidized sands in hot boxes comprises a support structure 1 on an upper stage 2 of which are mounted means 32,37,50,51 and 52 for adjustably changing the location of a mixer 30 incorporated in a sand preparing device 3, of a metering chamber 33 incorporated in a sand compacting device 4, of actuators 23 for joining the top and bottom sections of each core box 5, of actuators 25 for closing gates, and of supporting strips 10 for receiving finished cores. Mounted on the upper stage 2 of the support structure 1 at the core-box separating device 8 are means 54,53 and 44 for adjustably changing the location of a gate opening arrangement, of an arrangement for disjoining the top and bottom sections of each core box 5, and of pushers 43 incorporated in the core-box separating device 8; and means 49 for adjustably changing the location of receiving members of a feeding appliance 46 incorporated in a device 9 for delivering finished core, which means is arranged on the feeding appliance 46. <IMAGE>

Description

SPECIFICATION Apparatus for making cores from fluidized sands in hot boxes The present invention relates to foundary practice and more in particular to a hot-box core-making machine.

The machine of the invention may be used at mass-production plants of, for example, the sanitary engineering industry, automobile industry, electrical engineering and machine-building industries.

What is required is a core-making equipment that will be effective enough to ensure a wide range of production of cores having different sizes and different locations of print seats.

The invention provides an apparatus for making cores from fluidized sands in hot boxes, comprising a support structure having an upper and lower stage; mounted on the upper stage of the support structure and arranged in the direction of the technological process are a sand preparing device having mixers and means for changing the location of at least one mixer, said means being arranged on the upper stage of the support structure; a device for compacting a fluidized sand in each core box, said device having metering chambers with compacting actuators mounfted on cross-arms movable by means of appropriate drives, and means for changing the location of at least one metering chamber, said means being arranged on the upper stage of the support structure; a pusher for moving the core boxes through a heating chamber; a core-box separating device having members for pushing out cores from the core boxes and means for changing the location of said pushing-out members, said means being arranged on the upper stage of the support structure at the core-box separating device; a finished-core delivering device having a carriage whereupon are mounted a feeding appliance with a receiving plate carrying core-receiving members, and means for changing the location of the corereceiving members, said means being arranged on the feeding appliance; supporting strips intended for receiving finished cores; means for changing the location of the supporting strips, said means being arranged on the upper stage of the support structure, and, mounted on the lower stage of the support structure are a lifting table, a transfer table and a transport means for conveying the core boxes in the direction of the technological process; each of the core boxes having a top section and a bottom section and gates mounted on the top section thereof; drives for joining the top and bottom section of each core box, said drives being arranged on the upper stage of the support structure at the sand compacting device; means for changing the location of said drives, said means being arranged on the upper stage of the support structure; an arrangement for disjoining the top and bottom sections of each core box, said arrangement being disposed at the core-box separating device; means for changing the location of the disjoining arrange ment being disposed on the upper stage of the support structure; actuators intended for closing the gates and co-cperating therewith said actuators being fixed on the upper stage of the support structure at the sand compacting device; means for changing the location of the gate closing actuators, said means being arranged on the upper stage of the support structure; an arrangement intended for opening the gates and co-operating therewith, said arrangement being disposed at the core-box separating device; and means for changing the location of the gate opening arrangement said means being disposed on the upper stage of the support structure.

The means for changing the location of at least one mixer is preferably made in the form of strips fixed on the support structure and carrying the mixer movably mounted thereon.

The means for changing the location of at least one metering chamber incorporated in the sand compacting device is preferably made in the form of frames of which one is movably mounted on the support structure and the other one is arranged on the first frame so as to be able to move in the direction perpendicular to the travelling direction of the first frame, the second frame carrying a drive for actuating the cross-arm mounting the metering chamber with the compacting actuator.

Each of the means for changing the location of the drives for joining the top and bottom sections of each core box and of the gate closing actuators is preferably provided with a common beam movably mounted on the upper stage of the support structure and with brackets mounted on the beam for movement in the direction perpendicular to the travelling direction of the beam and carrying the core-box joining actuators and the gate closing actuators which are allowed to turn relative to the brackets.

The means for changing the location of the pushers incorporated in the core-box separating device is preferably made in the form of frames movably mounted on the separating device and carrying the pushers mounted thereon for movement in the direction perpendicular to the travelling direction of the frames.

Each of the means for changing the location of the arrangement for disjoining the top and bottom sections of each core box and of the gate opening arrangement is preferably made in the form of a beam movably mpunted on the upper stage of the support structure at the core-box separating device and carrying the core-box disjoining arrangement and the gate opening arrangement mounted thereon for movement in the direction perpendicular to the travelling direction of the beam.

The means for changing the location of the receiving members incorporated in the feeding appliance is preferably made in the form of strips mounted on the receiving plate for mutually perpendicular movement and serving basically as the core receiving members.

The means for changing the location of the supporting strips is preferably made in the form of slots formed in the body of each supporting strip at the places of their fixation to the support structure.

Such apparatus construction makes it possible to substantially expand production potentialities of the core-making equipment, well adapted to make cores of different sizes and with different spacing of core prings.

The invention will now be described, by way of example only, with reference to the accompanying drawings, wherein: Figure 1 is a general front view of an apparatus for making cores from fluidized sands in hot boxes; Figure 2 is a longitudinal sectional view of a core box of the apparatus shown in Figure 1; Figure 3 is a view taken along arrow A of Figure 1; Figure 4 is an enlarged view of section B of Figure 1; Figure 5 is a view taken along arrow C of Figure 1; Figure 6 is a view taken along arrow D of Figure 1; Figure 7 is a view taken along arrow E of Figure 1; Figure 8 is a view taken along arrow F of Figure 4; Figure 9 is a cross-section IX-IX of Figure 1 (a metering chamber with a compacting actuator is shown for better understanding of the drawing); Figure 10 is a cross-section X-X of Figure 7;; Figure 11 7 11 isaviewtaken along arrowG of Figure 1; Figure 12 is a cross-section XII-XII of Figure 6; and Figure 13 is a cross-section XIII-XIII of Figure 6.

The apparatus illustrated, which is suitable for the production of cores from fluidized sands in hot boxes, comprises a support structure 1 having an upper stage 2 whereupon are mounted, in the direction of the technological process, a sand preparing device 3, a device 4 for compacting the fluidized sand in core boxes 5, a pusher 6 for moving the core boxes 5 through a heating chamber 7, a device 8 for the separation of the core boxes 5, a device 9 for delivery of finished cores, and supporting strips 10 for receiving the finished cores.

Mounted on the lower stage 11 of the support structure 1, which is connected with the upper stage 2 thereof by means of a column 12, are a lifting table 13, a transfer table 14 and a transport means 15 provided in the form of live rollers for conveying the core boxes 5 in the direction of the technological process.

Each core box 5 (Figure 2) has a top section 16 and a bottom section 17, gates 18 mounted on the top section 16, a core withdrawing means 19, and an arrangement 20 for joining the top section 16 with the bottom section 17 of the core box 5. The gates 18 are formed with holes 21 which, during compacting and separating procedures and in the couse of transportation of the core boxes 5 by the transport means 15 and by the table 13 and 14, is brought in alignment with print holes 22 of the core box 5.

The top section 16 and bottom section 17 of each core box 5 are joined by means of appropriate actuators 23 (Figure 1) which are mounted on the support structure 1 at the sand compacting device 4 so as to act on the joining arrangement 20 which, as mentioned before, is placed within the core boxes 5.

The top and bottom section 16 and 17 are disjoined by means of an arrangement 24 (Figure 3) mounted on the core-box separating device 8 (Figure 1).

The gates 18 (Figure 2) of the core boxes 5 interact with actuators 25 (Figure 1) provided for closing the gates 18 and located on the support structure 1 at the sand compacting device 4, and with an arrangement 26 (Figure 4) for opening these gates 18 (Figure 2), which is located at the core-box separating device 8 (Figure 1).

The sand preparing device 3 comprises a feeder 27 for solid and liquid components, a mixer 28 with a drive 29, mounted on the upper stage 2 of the support structure 1, a mixer 30 with a drive 31 (Figure 5) and a means 32 (Figure 1) for changing the location of one of the mixers, namely, of the mixer 30. The location changing means 32 is disposed on the upper stage 2 of the support structure 1 and carries the mixer 30.

The device 4 for compacting the fluidized sand in the core boxes 5 comprises metering chambers 33 operably connected with compacting actuators 34 (Figure 5) and mounted on cross-arms 35 (Figure 1) which are suspended from rods of power cylinders or actuators 36 and operated by these actuators, and means 37 for changing the location of the metering chambers 33, which is disposed on the upper stage 2 of the support structure 1 and carries the actuators 36 for displacing the cross-arms 35 which carry the metering chambers 33 with the actuators 34.

The device 8 for separation of the core boxes 5 comprises a frame 38 with grapples 39, movable along columns 40 each having one of its ends secured on the upper stage 2 of the support structure 1, with the other end thereof carrying a frame 41 which mounts a drive 42 for actuating the frame 38 with the grapples 39. The core-box separating device 8 also comprises pushers 43 with built-in core punching members (not shown), and means 44 for changing the location of the pushers 43, which are disposed on the frame 41 and carrying the pushers 43.

The device 9 for delivery of finished cores includes a carriage 45 which mounts a feeding appliance 46.

The carriage 45 is slidable along the upper stage 2 of the support structure 1 by means of a drive 47. The feeding appliance 46 has a receiving plate 48 provided with members for receiving cores. The device 9 also includes a means 49 (Figure 6) for changing location of the receiving members of the feeding appliance 46 (Figure 1), which means is disposed on the feeding appliance 46.

The apparatus of the invention also incorporates a means 50 for changing the location of the actuators 23, a means 51 (Figure 7) for changing the location of the actuators 25, and a means 52 (Figure 6) for changing the location of the supporting strips 10, all the means being disposed on the upper stage 2 of the supporting structure 1.

The apparatus of the invention also comprises a means 53 (Figure 3) for changing the location of the arrangement 24 for disjoining the top and bottom sections 16 and 17 of each core box 5, and a means 54 (Figure 8) for changing the location of the arrangement 26 for opening the gates 18 of each core box 5, all the means being disposed on the frame 38 (Figure 1) of the core-box separating device 8.

The apparatus described is also provided with a carriage 55 for the final delivery of the core boxes 5 to the separating station. The carriage 55 is mounted on the upper stage 2 of the support structure 1 between the heating chamber 7 and the core-box separating device 8, being movable along the upper stage 2 by means of a drive 56.

The means 32 (Figure 5) for changing the location of the mixer 30 of the sand preparing device 3 is made in the form of strips 57 secured on the upper stage 2 of the support structure 1 and formed with slots 58. Mounted on the strips 57 for crosswise movement in the slots 58 is the mixer 30.

The means 37 (Figure 9) for changing the location of the metering chambers 33 of the sand compacting device 4 is made in the form of frames 59 and 60. The frame 59 is movably mounted on the upper stage 2 of the support structure 1. The frame 60 is mounted on the frame 59 for movement in the direction perpendicular to the travelling direction of the frame 59. To make the frames 59 and 60 movable, they are formed with slots 61 and 62, and are respectively provided with screws 63 and 64. Mounted on the frame 60 is the actuator 36 for moving the cross-arm 35 (Figure 1) which carries the metering chamber 33 with the compacting actuator 34.

Each of the means 50 (Figure 7) and 51 for changing the location of the actuators 23 and 25 has a common beam 65 placed for movement on the upper stage 2 of the support structure 1, and brackets 66 and 67 respectively mounted on the beam 65 for movement in the direction perpendicularto the travelling direction of the beam 65.

To make the beam 65 movable, it is formed with slots 68 (Figure 7); the brackets 66 and 67 are made movable by means of slots 69 provided in the beam 65 in perpendicular to the slots 68. The brackets 66 (Figure 10) and 67 have shackles 70 and 71 and stops 72 and 73, respectively. Fixed to the shackles 70 and 71 with the possibility to turn relative to the brackets 66 and 67 are the actuators 23 and 25.

The means 44 (Figure 11) for changing the location of the pushers 48 of the core-box separating device 8 is made in the form of frames 74 movably mounted on the frame 41 of the core-box separating device 8.

The frames 74 carry the pushers 43 which are mounted thereof for movement in the direction perpendicular to the travelling direction of the frames 74. To make the frames 74 and the pushers 43 movable, the frames 74 are formed with mutually perpendicular slots 75 and 76.

Each of the means 53 (Figure 3) and 54 (Figure 8) for changing the location of the arrangement 24 for joining the top and bottom sections 16 and 17 of the core box 5 and of the arrangement 26 for opening the gate 18 of the core box 5 is made in the form of beams 77 and 78 movably mounted on the columns 40 and the frame 38. The beams 77 (Figures 3 and 8) and 78 carry respectively the arrangements 24 and 26 which are mounted thereon for movement in the direction perpendicular to the travelling direction of the beams 77 and 78.

The beam 77 (Figure 3) is secured to the columns 40 by means of brackets 79 and is formed with slots 80 provided therein to permit the arrangement 24 to move therealong.

The beam 78 (Figure 8) is made movable by means of slots 81 formed in its body; the arrangement 26 being moved therealong by means of slots 82 also formed in the body of the beam 78.

The means 49 for changing the location of the receiving members of the feeding appliance 46 is made in the form of strips 83 which are placed on the receiving plate 48 for movement in the mutually perpendicular direction and which basicaliy serve as the core receiving strips. To permit movement of the strips 83 (Figure 12), their bodies are formed with slots 84, the body of the receiving plate 48 (Figure 6) being formed with slots 85.

The means 52 (Figures 6 and 13) for changing the location of the strips 10 is made in the form of slots 86 which are formed in the body of the strips 10 at places of their fixation on the upper stage 2 of the support structure 1.

Operation of a preferred apparatus will now be described.

Loose solid and liquid components are fed by the feeder 27 (Figure 1) to the mixer 28 wherein a fluidized sand is prepared and then delivered to the mixer 30 operated to distribute the sand between the metering chambers 33.

The core box 5 is raised by the lifting table 13 to occupy its upper position, the drives 36 are operated to lower the cross-arms 35, and the metering chambers 33 are pressed against the gates 18 (Figure 2) of the core box 5. Simultaneously, the actuators 23 (Figure 1) are operated to act on the arrangement 20 effective to join the top section 16 (Figure 2) and the bottom section 17 of the core box 5. Thereafter, the metering chambers 33 (Figure 1) are opened to permit the fluidized sand to be squeezed out therefrom by means of the actuators 34 (Figure 5) through the outlets 21 (Figure 2) of the gates 18 so as to pass into the core box 5 through the inlet holes 22.

Once the compacting procedure is over, the actuators 25 (Figure 1) are operated to displace the gates 18, thereby overlapping the inlet holes 22 of the core box 5, the metering chambers 33 are returned to their original position and then are closed to be thereafter filled with the next portion of the fluidized sand fed from the mixer 30. As this happens, the lifting table 13 is brought down to occupy its lower position and the sand-filled core box 5 is transferred by the pusher 6 to the heating chamber 7. At the same time, the carriage 55 receives the core box 5 with a finished core at the opposite end of the heating chamber 7. The drive 56 is operated to move the carriage 55 with the core box 5 to the core-box separating device 8.At the end of travel of the carriage 55, the gates 18 of the core box 5 interact with the opening arrangement 26 (Figure 4) and are displaced to bring the holes 21 in alignment with the inlet holes 22 of the core box 5, while the joining arrangement 20 (Figure 2) interact with the disjoining arrangement 24 (Figure 3) as a result of which the core-box top and bottom sections 16 and 17 are disengaged from one another.

Thetransfertable 14 (Figure 1) is raised to its upper position to receive the core box 5, which is held in place so as to permit precise alignment of the axes of the holes 22 with the axes of the pushers 43.

Next, the frame 38 with the grapples 39 is moved upwardly by the drive 42, with the core prints being punctured to bring its interior in communication with the atmosphere. Thereafter, the core box 5 is disassembled and a finished core is removed therefrom with the aid of the core withdrawal means 19 (Figure 2).

The carriage 45 (Figure 1) with the feeding appliance 46 is moved by the drive 46 toward the core-box separating device 8 so that the strips 83 are brought under the core. At the end of travel of the carriage 45, the feeding appliance 46 is operated to bring the strips 83 to the upper position in which they receive the core. As the carriage 45 is returned to its original position, the feeding appliance 46 is operated to bring down the strips 83 to their lower position so as to permit the core to be placed onto the supporting strips 10 over which the cores are moved in the direction of a discharging station.

The frame 38 with the grapples 39 is brought down by the drive 42 so as to effect assembly of the core-free box 5. The carriage 55 is returned to its original position in the direction of the heating chamber 7, while the transfer table 14 is lowered to place the core box 5 onto the transport means 15 operated to convey the box 5 to the lifting table 13 for the next compacting procedure.

Where the apparatus of the invention is to be used for the production of cores with different sizes and different disposition of print holes, it should be appropriately readjusted as described, by way of example, herein below.

1. Release the fastening bolts of the frames 59 (Figure 9) and 60 of the means 37 and turn the screw 63 to displace the frame 59 relative to the support structure 1 in the slots 61; by turning the screws 64, the frame 60 is displaced relative to the frame 59 in the slots 62. At this time, the drive 36 with the cross-arm 35 suspended therefrom and, consequently, the metering chamber 33 fixed on the cross-arm 35 will occupy a preset position.

Tighten the fastening bolts of the frames 59 and 60.

2. Release the bolts fastening the mixer 30 (Figure 5) to the strips 57 of the means 32 and displace the mixer 30 in the slots 58 in a manner to bring the outlets of the mixer 30 in contact with the inlets of the metering chambers 33 in their new position.

Tighten the bolts by which the mixer 30 is fastened to the strips 57.

3. Release the bolts by which the beam 65 (Figure 7) of the means 50 and 51 are fastened to the support structure 1 and those by which the brackets 66 and 67 are fastened to the beam 65. Displace the beam 65 in the slots 68 vertically and the brackets 66 and 67 in the slots 69 horizontally in a manner to ensure interaction of the joining actuators 23 and closing actuators 25 with the joining arrangement 20 and gates 18 of the in-coming core boxes 5. Tighten the fastening bolts of the beam 65 and of the brackets 66 and 67.

4. Release the bolts by which the pushers 43 (Figure 11) are fastened to the frames 74 of the means 44 and those fastening the frames 74 to the frame 41 if the core-box separating device 8. Dis place the frames 74 in the slots 75 relative to the frame 41 and the pushers 43 in the slots 76 relative to the frames 71 in a manner ta bring the axes of the pushers 43 in alignment with the axes of the inlet (print) holes 22 (Figure 2) of the newly arrived core boxes 5. Tighten the fastening bolts of the pushers 43 (Figure 11) and frames 74.

5. Release the bolts by which the brackets 79 (Figure 3) and the disjoining arrangement 24 are fastened to the beam 77 (Figure 3) of the means 53.

Displace the beam 77 with the brackets 79 relative to the columns 40 of the core-box separating device 8 (Figure 1) and the arrangement 24 in the slots 80 relative to the beam 77 in a manner to permit interaction of the disjoining arrangement 24 with the joining arrangement 20 of the newly arrived core box 5. Tighten the bolts fastening the beam 77 to the brackets 79, and the bolts by which the disjoining arrangement 24 is fastened to the beam 77.

6. Release the bolts by which the beam 78 (Figure 8) of the means 54 is fastened to the frame 38 (Figure 1) with the grapples 39 of the core-box separating device 8 and of the arrangement 26 (Figure 8) for opening the gates 18 (Figure 2) of the core box 5.

Replace the beam 78 (Figure 8) relative to the frame 38 in the slots 81 in a manner to permit interaction of the opening arrangement 26 with the gates 18 of the newly arrived core boxes 5. Tighten the fastening bolts of the beam 78 and of the arrangement 26 for opening the gates 18 of the core boxes 5.

7. Release the bolts by which the strips 83 (Figure 6) of the means 49 are fastened to the receiving plate 48 of the feeding appliance 46 (Figure 1) incorporated in the finished-core delivering device 9. Displace the strips 83 (Figure 6) relative to the receiving plate 43 in the slots 84 and 85 in conformity with the sizes and shape fo a new core in the core box 5.

Tighten the fastening bolts of the strips 83.

8. Release the bolts by which the supporting strips 10 (Figure 6) are fastened to the support structure 1.

Displace the supporting strips 10 relative to the support structure 1 in the slots 86 of the means 52 for a distance corresponding to the size of a new core.

Tighten the fastening bolts of the supporting strips 10.

9. Renew the set of core boxes of the apparatus.

10. Repeat the above-described operating cycle of the apparatus according to the invention.

With the apparatus of the invention it becomes possible to substantially expand production potentialities of the core-making equipment; to reduce the lead time thereof; to accelerate wide commercial application of the core-making equipment and to enhance its production efficiency. It also creates the possibility for setting up a series of machines adapted for effective production of the broadest possible range of cores to meet the stringest requirements.

Claims (9)

1. Apparatus for making cores from fluidized sand in hot boxes, comprising: a support structure having an upper and a lower stage; mounted on the upper stage of the support structure and arranged in sequence in the direction of the core-making pro cess: a sand preparing device having mixers and means for changing the location of at least one mixer, the said means being arranged on the upper stage of the support structure; a device for compacting fluidized sand in each core box, the said device having metering chambers with compacting actuators mounted on cross-arms movable by means of appropriate drives, and means for changing the location of at least one metering chamber, the said means being arranged on the upper stage of the support structure; a pusher for moving the core boxes through a heating chamber; a core-box separating device having members for pushing out cores from the core boxes and means for changing the location of the pushing-out members, the said means being arranged on the upper stage of the support structure; a finished-core delivering device having a carriage carrying a feeding appliance with a receiving plate carrying core-receiving members, and means for changing the location of the corereceiving members, the said means being arranged on the feeding appliance; and supporting strips intended for receiving finished cores and means for changing the location of the supporting strips, the said means being arranged on the upper stage of the support structure; mounted on the lower stage of the support structure, a lifting table, a transfer table, and a transport means for conveying the core boxes in the direction of the core-making process, each of the core boxes having a top section and a bottom section and gates mounted on the top section; drives for joining the top and bottom sections of each core box, the drives being arranged on the upper stage of the support structure adjacent the sand compacting device; means for changing the location of the said drives, the said means being arranged on the upper stage of the support structure; an arrangement for separating the top and bottom sections of each core box, the separating arrangement being disposed adjacent the core-box separating device; means for changing the location of the separating arrangement, the said means being disposed on the upper stage of the support structure; actuators intended for closing the gates, the actuators being mounted on the upper stage of the support structure adjacent the sand compacting device; means for changing the location of the gate closing actuators, the said means being arranged on the upper stage of the support structure; an arrangement intended for opening the gates, the opening arrangement being disposed adjacent the core-box separating device; and means for changing the location of the gate opening arrangement, the said means being disposed at the upper stage of the support structure.

2. Apparatus as claimed in claim 1, in which the means for changing the location of at least one mixer comprises strips fixed on the support structure and carrying the mixer movably mounted thereon.

3. Apparatus as claimed in claim 1 or 2, in which the means for changing the location of at least one metering chamber incorporated in the sand compacting device comprises a first frame which is movably mounted on the support structure and a second frame which is arranged on the first frame so as to be able to move in a direction perpendicular to the travelling direction of the first frame, the second frame carrying a device for actuating the cross-arm mounting the metering chamber with the compacting actuaton

4.Apparatus as claimed in any preceding claim, in which the means for changing the location of the drives for joining the top and bottom sections of each core box and of the gate closing actuators are provided with a common beam movably mounted on the upper stage of the support structure and with brackets mounted on the beam for movement in a direction perpendicular to the travelling direction of the beam and carrying the core-box joining actuators and the gate closing actuators, which are allowed to turn relative to the brackets.

5. Apparatus as claimed in any preceding claim, in which the means for changing the location of the pushers incorporated in the core-box separating device comprises frames movably mounted on the separating device and carrying the pushers mounted thereon for movement in a direction perpendicular to the travelling direction of the frames.

6. Apparatus as claimed in any preceding claim, in which the means for changing the location of the top and bottom sections of each core box and of the gate opening arrangement comprises a beam movably mounted on the upper stage of the support structure adjacent the core-box separating device and carrying the core-box separating arrangement and the gate opening arrangement mounted thereon for movement in a direction perpendicular to the travelling direction of the beam.

7. Apparatus as claimed in any preceding claim, in which the means for changing the location of the receiving members incorporated in the feeding appliance comprises strips mounted on the receiving plate for mutually perpendicular movement and serving as core receiving members.

8. Apparatus as claimed in any preceding claim, in which the means for changing the location of the supporting strips comprises slots formed in the body of each supporting strip at the places of their fixation to the support structure.

9. Apparatus for making cores from fluidized sand in hot boxes, substantially as described with reference to, and as shown in, the accompanying drawings.