We Claim:
1. A process for manufacturing pellets of material that can be used as a road binder
or as a sealing binder, comprising a core and a coating layer, in a fluidized air bed
facility (10), said process comprising the following steps:
(i) feeding the cores (14) into the process chamber (II),
(ii) fluidizing the cores (14) present in the process chamber (II), by injecting an air
stream (16), and
(iii) feeding the coating layer precursor composition (18) to the fluidized bed by means
of at least one spray nozzle (20) emerging from below into the fluidized bed (10),
said facility comprising, in the process chamber (II), at least one insert (22) delimiting a
fluidized bed zone (28) in which the air flow rate is higher relative to the rest of the
process chamber (II),
said core consisting of a first composition comprising at least one material chosen from:
a bitumen base, a pitch and a clear binder, and said coating layer consisting of a second
composition comprising at least one viscosifying compound and at least one anticaking
agent.
2. The process for manufacturing pellets of material as claimed in claim 1, in a
fluidized air bed facility (10), the cores (14) being placed in a process chamber (II) of
the fluidized air bed facility, wherein a coating layer precursor composition (18) is fed
to the fluidized bed (12) by means of at least one spray nozzle (20) emerging from
below into the fluidized bed, and wherein an air stream (16) is fed from below to the
fluidized bed in order to maintain the fluidized bed and to dry and/or cool the cores (14)
placed in the fluidized bed (12), said process chamber (II) of the fluidized air bed facility
(10) comprising at least one insert (22) above each spray nozzle, wherein:
a) the air stream is guided by an incoming air housing (I) comprising at least one incoming air chamber (26),
b) the zone of the fluidized bed formed by the incoming air chamber (26) has a zone (28) with a higher flow rate of the air stream (16) applied to the cores,
c) the coating layer precursor composition (18) is sprayed into the zone (28) operating at a higher flow rate,
d) the cores originating from the zone (28) at a higher flow rate are returned to the fluidized bed (12),
e) a portion of the cores present in the fluidized bed (12) is returned to the zone (28) at a higher flow rate, so that a circulation of cores appears between the fluidized bed (12) and the zone (28) at a higher flow rate, and
f) the insert(s) (22) provided for in the process chamber of the fluidized bed facility above each spray nozzle (20) are arranged in the form of facility pieces that can be

adjusted in height and in width or diameter, the respective lower edges (15) of which are adjustably spaced from the surface of the bottom of the fluidized bed (13), said cores consisting of a first composition comprising at least one material chosen from: a bitumen base, a pitch and a clear binder, and said coating layer consisting of a second composition comprising at least one viscosifying compound and at least one anticaking agent.
3. The process as claimed in claim 1 or as claimed in claim 2, wherein the insert is cylindrical in shape.
4. The process as claimed in any one of claims 1 to 3, which is carried out at a temperature of less than or equal to 30°C, preferably less than or equal to 25°C, and even more preferentially at a temperature of less than or equal to 20°C.
5. The process as claimed in any one of claims 1 to 4, wherein the viscosifying compound is chosen from cellulose ethers.
6. The process as claimed in any one of claims 1 to 5, wherein the cellulose ether is chosen from methylcellulose, ethylcellulose, hydroxymethylcellulose, hydroxyethyl-cellulose (HEC), hydroxypropylcellulose (HPC), hydroxyethylmethylcellulose (HEMC), hydroxypropylmethylcellulose (HPMC), hydroxybutylmethylcellulose (HBMC), carboxy-methylcellulose (CMC), sodium carboxymethylcellulose (Na-CMC), carboxymethyl-sulfoethylcellulose, hydroxyethylmethylcarboxymethylcellulose.
7. The process as claimed in claim 5 or as claimed in claim 6, wherein the cellulose ether is chosen from hydroxyethylmethylcellulose, hydroxypropylmethylcellulose, hydroxybutylmethylcellulose, even more advantageously hydroxypropylmethyl-cellulose.
8. The process as claimed in any one of the preceding claims, wherein the coating layer comprises:
o one or more viscosifying compounds and
o at least 10% of one or more anticaking agents,
the percentages being expressed by weight relative to the total weight of the coating
layer.
9. The process as claimed in any one of the preceding claims, wherein the anticaking
compound is chosen from: talc; fines generally less than 125 urn in diameter, such as
siliceous fines, with the exception of limestone fines, sand, such as Fontainebleau
sand; cement; carbon; wood residues, such as lignin, lignosulfonate, conifer needle

powders or conifer cone powders, in particular of pine; rice husk ash; glass powder; clays, such as kaolin, bentonite or vermiculite; alumina, such as alumina hydrates; silica; silica derivatives, such as fumed silica, functionalized fumed silica, in particular hydrophobic or hydrophilic fumed silica, pyrogenic silicas, in particular hydrophobic or hydrophilic pyrogenic silicas, silicates, silicon hydroxides and silicon oxides; plastic powder; lime; hydrated lime; plaster; rubber crumb; polymer powder, where the polymers are such as styrene/butadiene (SB) copolymers or styrene/butadiene/styrene (SBS) copolymers; and mixtures of these materials.
10. The process as claimed in any one of the preceding claims, wherein the first composition has a needle penetrability measured at 25°C according to the standard EN 1426 of from 5 to 330 1/10 mm, preferably from 20 to 220 1/10 mm.
11. The process as claimed in any one of the preceding claims, wherein the first composition also comprises at least one chemical additive chosen from: an organic compound, a paraffin, a polyphosphoric acid, and mixtures thereof.