WO2025146523A1 - Processing plant for obtaining expanded ore - Google Patents

Abstract

The present invention relates to a processing plant (1) for processing expandable ore, comprising a furnace (2), comprising an enclosure (14) configured for expansion of the expandable ore, a burner (10) and a channeling member (22) for channeling a flame generated by the burner (10), the processing plant (1) comprising at least one device (34) for introducing the expandable ore which leads into the enclosure (14), the channeling member (22) being disposed between the enclosure (14) and the burner (10).

Description

DESCRIPTION

Title: Processing plant for obtaining expanded ore

The present invention relates to the field of the production of expanded ores, and more particularly to the means used to obtain such expansion of the ores.

For example, perlite is a mineral of volcanic origin which is used, in its expanded form with a low density, in plasters and coatings. In these plasters and coatings, expanded perlite allows on the one hand a lightening of the final product, and on the other hand a gain in workability and workability.

For expansion, the ore is introduced in the form of fine powder into a specially designed furnace and heated to over 850°C. The expansion is almost instantaneous, transforming the ore in the form of fine powder into a material with low density and high insulating and lightweighting efficiency.

In the furnaces of the prior art, the quality of expansion is not always satisfactory, particularly in terms of homogeneity concerning the size of the expanded ore grains. Indeed, if, upon its introduction into the furnace, the ore is exposed to a gas flow whose temperature and speed are heterogeneous within the furnace, the particles of the same size will not all be expanded in the same way and their size after expansion will then be variable. Similarly, if the ore introduced into the furnace has a large particle size dispersion, there will be differences in expansion within the same furnace; the small grains will thus be over-expanded while the large grains will be under-expanded. However, over-expanded ore particles, due to their open porosity, will absorb several times their weight in water and make the plaster or coating difficult to work with, and conversely, under-expanded particles do not allow sufficient lightening of so-called lightweight plasters and coatings which incorporate expanded ore.

The present invention falls within this context by proposing equipment configured to achieve expansion of the ore grains in a homogeneous manner, so as to obtain an expanded ore meeting the requirements of both weight reduction and workability.

The main subject of the present invention is therefore an installation for processing expandable ore, comprising a furnace comprising an enclosure configured for expansion of the expandable ore, a burner and a channeling member for a flame generated by the burner, the processing installation comprising at least one device for introducing the expandable ore opening into the enclosure, the channeling member being arranged between the enclosure and the burner.

The expandable ore processing facility according to the invention is configured to achieve homogeneous expansion of the expandable ore within the enclosure. “Expansion” means rapid evaporation of the water contained in the material, thereby increasing its volume. The expandable ore is, for example, perlite. Alternatively, the expandable ore is vermiculite or clay. The expandable ore processing facility comprises a furnace that extends primarily in a vertical direction substantially perpendicular to the ground on which the processing facility rests. In order to convey the expandable ore to the furnace, the processing facility has at least one device for introducing the expandable ore that opens into the enclosure.

The furnace comprises successively, starting from the ground, a burner, a channeling member and an enclosure within which the expansion takes place. The burner is configured to generate a gas flow such as a flame which heats the expandable ore for its expansion. The channeling member makes it possible to place, within the processing installation, the burner at a distance from the furnace enclosure. For this purpose, it is interposed between these two elements. Such a distance between the burner and the furnace enclosure makes it possible to homogenize the gas flow, which allows a more homogeneous expansion of the expandable ore since within the enclosure each particle is exposed to a gas flow of approximately the same radial temperature and the same radial velocity.

According to an optional characteristic of the invention, the channeling member is a tube whose length is greater than its width. The channeling member is a hollow tube configured to channel the gas flow from the burner within it. The tube is elongated and straight, i.e., free of bends that would disrupt the flow of the gas flow. The channeling member has a principal elongation direction substantially parallel to the vertical direction. The length of the channeling member is measured in a plane in which its principal elongation axis extends. The width of the channeling member corresponds to its largest dimension measured in a plane perpendicular to its principal elongation axis. In the case of a channeling member with a round cross-section, its principal elongation axis corresponds to its axis of revolution and its width corresponds to the diameter of the channeling member.

According to an optional characteristic of the invention, the length of the channeling member is at least once the width of the furnace enclosure.

The length of the pipe member determines a distance between the burner and the furnace enclosure. It makes it possible to determine by extension a homogeneity of the gas flow, such homogeneity being improved by moving the burner away from the furnace enclosure. This length is measured substantially perpendicular to the ground on which the treatment installation rests, that is to say in the vertical direction, while the width of the enclosure is measured in a plane perpendicular to the vertical direction. The length of the pipe member is for example greater than one times the width of the enclosure and preferably equal to five to six times this width, that is to say greater than one time (preferably five to six times) the diameter of the enclosure for a furnace with a round cross-section.

According to an optional characteristic of the invention, a section of the furnace enclosure is substantially equivalent to a section of the channeling member.

It is understood here that the section of the furnace enclosure and the section of the ducting member are the same within manufacturing tolerances. As a result, the burner is arranged at a distance from the furnace enclosure which corresponds to at least one time the width of the ducting member. According to an optional characteristic of the invention, the enclosure and the channeling member are surrounded by heat-insulating thermal protection.

Thermal insulation is, for example, made of ceramic wool. Such thermal protection constitutes a physical barrier that limits heat loss and thus ensures better homogeneity of the gas flow, by preventing contact between the enclosure and the piping system and the ambient air, which would cause a drop in temperature inside the enclosure and the piping system, particularly at the level of their walls. The use of thermal insulation also protects operators of the heat treatment facility against high temperatures emanating from the furnace.

According to an optional characteristic of the invention, the device for introducing the expandable ore comprises at least a first member for introducing the expandable ore and a second member for introducing the expandable ore.

The presence of a plurality of distinct expandable ore introduction members allows the introduction of the expandable ore at different heights in the furnace enclosure. Furthermore, in certain embodiments each of the expandable ore introduction members is dedicated to a type of particle size of the expandable ore, for example with the first expandable ore introduction member configured for the introduction of particles whose size is included in a first range of values and the second expandable ore introduction member configured for the introduction of particles whose size is included in a second range of values. The particle sizes may vary depending on the application.

According to an optional characteristic of the invention, the first expandable ore introduction member and the second expandable ore introduction member open into the enclosure at different distances from the burner, these distances being measured along a main extension direction of the enclosure.

The first expandable ore introduction member is, for example, arranged at a greater distance from the burner than the second expandable ore introduction member, this distance being measured in the vertical direction. Such a difference height between the first expandable ore introduction member and the second expandable ore introduction member makes it possible to obtain, for a homogeneous and constant gas flow, a different expansion for the particles circulating within the first expandable ore introduction member and the particles circulating within the second expandable ore introduction member. Thus, the particles introduced via the first expandable ore introduction member have, once expanded, a greater apparent density than particles which would be introduced via the second expandable ore introduction member. The introduction height will be chosen according to the desired apparent density, without having to significantly modify the burner settings.

According to an optional feature of the invention, a distance between the first expandable ore introduction member and the second expandable ore introduction member is of the order of one to four meters.

Such a distance is measured in a direction substantially perpendicular to the ground on which the treatment installation rests.

According to an optional characteristic of the invention, at least one of the first expandable ore introduction member and the second expandable ore introduction member comprises a plurality of conduits arranged radially around the enclosure.

The expandable ore introduction members comprise, depending on the embodiments, either a single pipe or a plurality of pipes connected to the enclosure. In the case of a plurality of pipes, these are distributed radially around a diameter of the enclosure. In the presence of two pipes, these are arranged at 180° to each other, while in the presence of four pipes they are arranged at 90° to each other.

According to an optional characteristic of the invention, the treatment installation comprises at least one discharge member connected to the device for introducing the expandable ore. The discharge member is configured to convey the expandable ore to the expandable ore introduction device, and if applicable to each of the expandable ore introduction members. The expandable ore introduction device in turn conveys the expandable ore particles to the furnace enclosure, into which they fall by gravity.

According to an optional feature of the invention, the discharge member is at a first end of the treatment installation, the burner being arranged at a second end of the treatment installation opposite the first end.

The first end and the second end of the processing plant are opposite each other in the vertical direction. The first end here corresponds to a high portion of the processing plant, while the second end is in contact with the ground. Due to the arrangement of the discharge member opposite the burner, it is possible to control, as a function of the length of the expandable ore introduction device, the distance at which the expandable ore particles are introduced relative to the burner. Thus, the shorter an expandable ore introduction member is, the closer it is to the discharge member, and a fortiori the further it is from the burner. Conversely, if the expandable ore were introduced into the enclosure closer to the second end and therefore to the burner, it would be difficult to expand the expandable ore homogeneously. It would indeed be necessary to adjust the oven settings, but too low a power and/or temperature would result in inadequate aeraulic operation of the oven.

According to an optional characteristic of the invention, the treatment installation comprises a suction member for the expanded ore.

The suction device takes the form of a fan. It is configured to produce an upward flow of air within the furnace enclosure. The enclosure is thus under negative pressure, the expandable ore being sucked out of this enclosure by the upward flow of air as soon as it is expanded. The ore is, for example, sucked in at a speed of around 5 to 20 meters per second. According to an optional feature of the invention, the treatment installation comprises a spraying device.

This spraying device is, for example, placed on a pipe that allows the ore to be evacuated from the furnace once it has been expanded. The role of the spraying device is to project a coating, for example a water-repellent coating, onto the expanded ore particles.

The invention further relates to a method of expanding expandable ore in a processing facility as previously discussed, in which the expandable ore is introduced into the enclosure via the expandable ore introduction device, the burner generating a flame configured to heat a gas stream passing through the channeling member in order to heat the expandable ore within the enclosure.

During this expansion process, the burner forms a flame intended to heat a gas flow. This flame does not come into direct contact with the expandable ore; it extends, for example, to half the height of the channeling member, this height being measured perpendicular to the ground. Generally, the flame does not reach the junction point between the channeling member and the furnace enclosure. It is the gas flow heated by the flame that passes through the channeling member to the furnace enclosure. The expandable ore is conveyed into this enclosure via the expandable ore introduction device, and it is expanded in the furnace enclosure when it meets the gas flow. The process for expanding the expandable ore according to the invention makes it possible to control the homogeneity of the expanded ore particles, the distance between the burner and the enclosure resulting from the presence of the channeling member allowing radial homogenization of the gas flow both in temperature and in speed.

Other characteristics, details and advantages of the invention will emerge more clearly on reading the description which follows on the one hand, and examples of embodiment given for informational and non-limiting purposes with reference to the appended drawings on the other hand, in which:

[Fig. 1] illustrates, schematically, a front view of part of a plant of treatment of expandable ore according to the invention, comprising a furnace, a device for introducing the expandable ore and a discharge member;

[Fig. 2] illustrates, schematically, a side view of the expandable ore processing installation of Figure 1, additionally comprising an expandable ore extraction pipe connected to the furnace.

The features, variants and different embodiments of the invention may be combined with each other in various combinations, provided that they are not incompatible or mutually exclusive. In particular, variants of the invention may be conceived comprising only a selection of features described below in isolation from the other features described, if this selection of features is sufficient to confer a technical advantage and/or to differentiate the invention from the prior art.

In the figures, elements common to several figures retain the same reference.

Figures 1 and 2 thus schematically illustrate an expandable ore processing installation 1 according to the invention. This expandable ore processing installation 1 is configured to transform the expandable ore with a view to its integration into plasters or even into coatings, so as to offer products manufactured from these plasters or coatings which are on the one hand easier to work with and on the other hand lighter. For this purpose, the expandable ore processing installation 1 is more particularly configured to carry out an expansion of the expandable ore.

The expandable ore processing plant 1 comprises a furnace 2, which corresponds to the portion of the expandable ore processing plant 1 which participates in its expansion. This furnace 2 extends mainly in a vertical direction which corresponds to a direction substantially perpendicular to a ground 4 on which the expandable ore processing plant 1 rests.

The oven 2 extends, in this vertical direction, between a first end 6 and a second end 8 opposite each other. The second end 8 is the end of the oven 2 which is in the vicinity of the ground 4, while the first end 6 is at a distance from this ground 4.

The second end 8 of the furnace 2 is equipped with a burner 10 capable of generating a gas flow in order to heat the expandable ore to temperatures of the order of 1000°C. This burner 10 is, depending on the embodiments, either arranged on the floor 4, or, as is the case in the embodiment illustrated in the figures, carried by a structure 12 of the furnace 2 in the vicinity of the floor 4. The structure 12 is, for example, a supporting metal structure which supports various elements of the furnace 2.

The structure 12 also carries an enclosure 14, visible in dotted lines in Figure 1, which corresponds to a main body of the furnace 2 and which is intended to receive the expandable ore for its expansion. The enclosure 14 is here a pipe of substantially round section, this round section being assessed in a plane substantially parallel to the ground 4, in other words in a plane perpendicular to the vertical direction. The enclosure 14 is delimited by a first vertical end 16 oriented towards the first end 6 of the furnace 2 and by a second vertical end 18 oriented towards the second end 8 of the furnace 2. More precisely, the first vertical end 16 of the enclosure 14 is in the vicinity of the first end 6 of the furnace 2, while the second vertical end 18 of this enclosure 14 is opposite the second end 8 of the furnace 2 but at a distance from it and therefore at a distance from the ground 4. It is understood from the above that the enclosure 14 is arranged at a distance from the burner 10.

The enclosure 14 of the furnace 2 is here equipped with a thermal protection 20 which encircles it, the thermal protection 20 being more particularly arranged around the enclosure 14 and the pipe member 22 in a concentric manner. The thermal protection 20 is configured to protect the operators and users of the expandable ore processing installation 1 against the high temperatures which are released by the furnace 2 and to limit the heat losses during a process of expanding the expandable ore which will be detailed later.

As mentioned previously, the enclosure 14 is arranged at a distance from the burner 10. More precisely, the enclosure 14 is separated from the burner 10 at least by a member of duct 22, which is, in the vertical direction, interposed between the enclosure 14 and the burner 10. In other words, starting from the floor 4, the furnace 2 comprises the burner 10, the duct member 22 and the enclosure 14.

The channeling member 22, which is visible in dotted lines in Figure 1, is configured to guide within it the gas flow generated by the burner 14. The distance imposed by the presence of the channeling member 22 between the burner 14 on the one hand and the enclosure 14 on the other hand makes it possible in particular to homogenize the gas flow prior to its arrival in the enclosure 14.

The channeling member 22 is a straight tube. It extends mainly in the vertical direction, between a first edge 24 which is connected to the second vertical end 18 of the enclosure 14 and a second edge 26 which is opposite the burner 10. Between the channeling member 22 and the burner 10, the furnace 2 comprises a nozzle 28. This nozzle 28 is more precisely mounted on the second edge 26 of the channeling member 22. It makes it possible to facilitate the passage of the gas flow generated by the burner 10 within the channeling member 22. The nozzle 28 has, for example, a conical shape, so that it widens as it moves away from the second edge 26.

As can be seen in Figure 1, the pipe member 22 has two flanges 30, that is to say a flange 30 in the vicinity of each of its first edge 24 and its second edge 26.

The pipe member 22 has a generally elongated shape; it is thus understood that its length, that is to say its dimension measured along the vertical direction, is greater than its width, which is measured in a plane perpendicular to the vertical direction. The pipe member 22 here has a round shape. As a result, the length of the pipe member 22 is greater than its diameter. The length of the pipe member 22 is preferably between five and six times its width, in other words between five and six times its diameter.

Furthermore, a section of the pipe member 22 is, within manufacturing tolerances, substantially equivalent to the section of the enclosure 14. In the figures, such a correspondence between the section of the pipe member 22 and the section of the enclosure 14 is visible in dotted lines through the thermal protection 20 which forms an excess thickness around the enclosure 14 and the channeling member 22.

Within the expandable ore processing plant 1, the expandable ore is conveyed to the furnace 2 via a transport pipe, not shown in the figures. This transport pipe leads the expandable ore to a discharge member 32 of the expandable ore processing plant 1, this discharge member 32 being arranged in the vicinity of the first end 6 of the furnace. It is understood that the discharge member 32 is therefore opposite the burner 10 in the vertical direction.

The discharge member 32 has a funnel shape. It is connected, in addition to the transport pipeline, to an expandable ore introduction device 34 which has the function of conveying the expandable ore to the enclosure 14. The expandable ore introduction device 34 is arranged at the first end 6 of the furnace 2. According to the embodiments, this expandable ore introduction device 34 comprises either a single expandable ore introduction member 36, or a plurality of such expandable ore introduction members 36. As shown in Figures 1 and 2, the expandable ore introduction device 34 comprises three expandable ore introduction members 36, including a first expandable ore introduction member 36A, a second expandable ore introduction member 36B and a third expandable ore introduction member 36C.

As illustrated in the figures, the expandable ore introduction members 36 open into the enclosure 14 of the furnace 2 at different heights, in other words at different distances from the burner 10. Such distances are measured in the vertical direction. Here, the first expandable ore introduction member 36A opens into the enclosure 14 at a first distance DI which is greater than a second distance D2 measured between the second expandable ore introduction member 36B and the burner 10, this second distance D2 itself being greater than a distance D3 between the third ore introduction member expandable 36C and the burner 10. In other words, from the first end 6 of the furnace 2 to its second end 8, the first expandable ore introduction member 36A, the second expandable ore introduction member 36B and the third expandable ore introduction member 36C are arranged in this order. It is understood that relative to the ground 4, the first expandable ore introduction member 36A corresponds within the enclosure 14 to a high introduction point, the second expandable ore introduction member 36B to a middle introduction point, and the third expandable ore introduction member 36C to a low introduction point. For example, a distance D4 measured between the point where the first expandable ore introduction member 36A opens into the enclosure 14 and the point where the second expandable ore introduction member 36B opens into the enclosure 14 is of the order of one to four meters.

Although each expandable ore introduction member 36 is here represented in the form of a single conduit opening into the enclosure 14, one could imagine, without departing from the scope of the invention, embodiments in which at least one of the expandable ore introduction members 36, possibly all of the expandable ore introduction members 36, have a plurality of conduits. If necessary, these pipes are distributed radially around the enclosure 14, the pipes then being arranged equidistant from each other around the enclosure 14. It should be noted that in the presence of a plurality of pipes for a given expandable ore introduction member 36, all these pipes open into the enclosure 14 at the same height, that is to say at the same distance from the burner 10. In other words, all the pipes forming the same expandable ore introduction member 36 are arranged over a diameter of the enclosure 14.

A process for expanding expandable ore using the expandable ore processing plant 1 will now be detailed. During this expansion process, the burner 10 is ignited to generate a flame which heats a gas stream. This heated gas stream extends through the nozzle 28 and the channeling member 22 to the enclosure 14 of the furnace 2. Expandable ore of grain size adapted is conveyed, via the transport pipeline, to the discharge member 32. The discharge member 32 then distributes the expandable ore to the expandable ore introduction device 34, more precisely to one of its expandable ore introduction members 36, so that it is introduced into the enclosure 14. The expandable ore falls into the enclosure 14 and is expanded when it encounters the gas flow.

Depending on the expandable ore introduction member 36 through which it is conveyed to the enclosure 14, the ore has different actual densities, granulometric dispersions, particle sizes and water absorptions after expansion.

For example, tests were carried out in a pilot furnace 2 equipped with three expandable ore introduction devices 36, including the first expandable ore introduction device 36A which corresponds to the high introduction point, the second expandable ore introduction device 36B which corresponds to the middle introduction point and the third expandable ore introduction device 36C which corresponds to the low introduction point. The flow rate of furnace 2 is 3.0 ± 0.1 kg ore/h. The expandable ore tested is perlite. Ores of different initial particle sizes, referenced perlite A, perlite B and perlite C were expanded. The characteristics of the raw materials are grouped in Table 1. The particle sizes are measured in the dry process using a Malvern Mastersizer 3000 laser granulometer. The diameter (d50) represents the particle size for which 50% of the volume of the expanded ore has a finer particle size. On the same principle, the different quantiles such as the first decile (dl0) or last decile (d90) represent the particle size for which 10% and 90% of the volume of expanded ore are finer. The span characterizes the dispersion of the particle size. It is calculated by the formula span = (d90-dl 0)/d50.

| span | 1,16 | 0.97 | 1.11 | Table 1

| span | 1.16 | 0.97 | 1.11 |

For each unexpanded perlite, tests are carried out using the various introduction members 36A, 36B, 36C. The temperature of the furnace 2, which is measured at the first end 6 of the furnace 4 at a temperature measuring point illustrated in Figure 1 by a white arrow, is adjusted in order to obtain expanded perlites of the desired apparent density. Apparent density is the characteristic usually targeted for selecting expanded ore for use in plaster and coating formulations. The particle size, apparent density, true density and water absorption of the resulting perlites are then measured.

Bulk density is measured by weighing the amount of perlite needed to fill a container of IL. The result given is the average of two consecutive measurements.

Actual density is measured using an Anton Paar ULTRAPYC 5000 helium pycnometer according to the manufacturer's recommendations. Actual density impacts the post-mixing density of formulations containing expanded perlite.

Water absorption is measured by immersing a given mass Ml of expanded perlite in water for 15 minutes. The unabsorbed water is then removed and the expanded perlite reweighed to determine a mass M2. The water absorption factor expressed in percent is calculated as follows: (M2-Ml)/Mlxl00. Water absorption affects the workability of formulations containing expanded perlite, the effect is more negative the higher the water absorption of expanded perlite.

Tel que cela a été évoqué précédemment, les différents points d’introduction évoqués dans le tableau 2 correspondent chacun à l’un des organes d’introduction de minerai expansible 36, à savoir le premier organe d’introduction du minerai expansible 36A pour le point d’introduction haut, le deuxième organe d’introduction du minerai expansible 36B pour le point d’introduction médian et le troisième organe d’introduction du minerai expansible 36C pour le point d’introduction bas. Table 2. Characteristics of expanded perlites.

As mentioned previously, the different introduction points mentioned in Table 2 each correspond to one of the expandable ore introduction members 36, namely the first expandable ore introduction member 36A for the high introduction point, the second expandable ore introduction member 36B for the middle introduction point and the third expandable ore introduction member 36C for the low introduction point.

The two-by-two comparison of tests C1 and D1, C2 and D2 respectively shows that for the same perlite and a comparable furnace temperature 2, the median size of the particles after expansion is larger and their actual density as well as their apparent density is lower when a lower introduction point is used and the particles are subjected to a higher temperature.

The two-by-two comparison of tests A1 and A2, B1 and B2, Cl and C2, DI and D2 respectively shows that for the same apparent density it is possible to obtain expanded perlites with different properties by varying the choice of the expandable ore introduction member 36, i.e. the introduction point, and the temperature of the furnace 2, and therefore to more precisely control the quality of the expanded ore. The actual density or span is lower the further the expandable ore introduction member 36 is from the burner 10. A lower actual density is more advantageous because it makes it possible to obtain greater lightening power for a given mass of expanded perlite.

Once expanded, the ore leaves the enclosure 14 via an extraction pipe 38. This extraction pipe 38 is at a first end connected to the first vertical end 16 of the enclosure 14, and at a second end equipped with a cyclone 44, itself connected to a suction member 40, for example a fan, which makes it possible to suck the expanded ore out of the enclosure 14.

The extraction pipe 38 extends mainly parallel to the ground 4. It is, in certain embodiments, carrying a spraying device 42. This spraying device 42 comprises at least one nozzle arranged within or on the walls of the extraction pipe 38 and configured to diffuse onto the ore particles. expanded a coating solution, for example a solution or dispersion of a water-repellent agent.

In order to be collected, the expanded particles pass through a cyclone 44, which is arranged in the vicinity of the second end of the discharge pipe 38 and the suction member 40. In certain embodiments, the finest particles are stopped by a filter, not illustrated in the figures.

The present invention thus proposes an installation for processing expandable ore within which the ore is expanded homogeneously, in particular thanks to a distance established between a burner and a heating enclosure of the installation, such a distance resulting from the addition within the installation of a pipeline member.

The present invention cannot, however, be limited to the means and configurations described and illustrated here and it also extends to any equivalent means and configuration as well as to any technically effective combination of such means.

Claims

1. Expandable ore processing installation (1), comprising a furnace (2), comprising an enclosure (14) configured for expansion of the expandable ore, a burner (10) and a channeling member (22) for a flame generated by the burner (10), the processing installation (1) comprising at least one device for introducing the expandable ore (34) opening into the enclosure (14), the channeling member (22) being arranged between the enclosure (14) and the burner (10), the length of the channeling member (22) being at least once the width of the enclosure (14) of the furnace (2). 2. Treatment installation (1) according to the preceding claim, in which the pipe member (22) is a tube whose length is greater than its width. 3. Treatment installation (1) according to any one of the preceding claims, in which a section of the enclosure (14) of the furnace (2) is substantially equivalent to a section of the pipe member (22). 4. Treatment installation (1) according to any one of the preceding claims, in which the enclosure (14) and the pipe member (22) are surrounded by heat-insulating thermal protection (20). 5. Processing plant (1) according to any one of the preceding claims, in which the expandable ore introduction device (34) comprises at least a first expandable ore introduction member (36, 36A) and a second expandable ore introduction member (36, 36B). 6. Treatment installation (1) according to the preceding claim, in which the first expandable ore introduction member (36, 36A) and the second expandable ore introduction member (36, 36B) open into the enclosure (14) at different distances (DI, D2) from the burner (10), these distances (DI, D2) being measured along a main extension direction of the enclosure (14). 7. Processing installation (1) according to the preceding claim, in which a distance (D4) between the first expandable ore introduction member (36, 36A) and the second expandable ore introduction member (36, 36B) is of the order of one to four meters. 8. Processing plant (1) according to any one of claims 5 and 6, wherein at least one of the first expandable ore introduction member (36, 36A) and the second expandable ore introduction member (36, 36B) comprises a plurality of conduits arranged radially around the enclosure (14). 9. Processing installation (1) according to any one of the preceding claims, comprising at least one discharge member (32) connected to the device for introducing the expandable ore (34). 10. Treatment installation (1) according to the preceding claim, in which the discharge member (32) is at a first end (6) of the treatment installation (1), the burner (10) being arranged at a second end (8) of the treatment installation (1) opposite the first end (6). 11. Treatment installation (1) according to any one of the preceding claims, comprising a suction member (40) for the expanded ore. 12. Treatment installation (1) according to any one of the preceding claims, comprising a spraying device (42). 13. A method of expanding expandable ore in a processing facility (1) according to any preceding claim, wherein expandable ore is introduced into the enclosure (14) via the expandable ore introduction device (34), the burner (10) generating a flame configured to heat a gas flow passing through the channeling member (22) in order to heat the expandable ore within the enclosure (14). 14. Expanded ore obtained from the expansion process according to the preceding claim.