AU2006259214A1

AU2006259214A1 - Method for making carbon powder and installation therefor

Info

Publication number: AU2006259214A1
Application number: AU2006259214A
Authority: AU
Inventors: Jean-Sebastien Hery
Original assignee: Thermya
Current assignee: Thermya
Priority date: 2005-07-07
Filing date: 2006-06-28
Publication date: 2007-02-01
Anticipated expiration: 2026-06-28
Also published as: AU2006259214A8; AU2006259214B2; WO2007006990A3; WO2007006990A2; EP1899422A2; FR2888230A1; FR2888230B1

Description

We, JMZ International of 40 bis, rue Villon 69008 LYON (France), represented by Mr. Jean-Marie Zilliox, Managing Director, hereby certify that we are well acquainted with the French and English languages and that to the best of our knowledge and belief the following is a true translation made by us of the original text of the attached International Patent Application entitled ",Procdg defabrication de poudre de carbone et installation de mieen wuvre" (Method for producing carbon powder and installation for implementing same) No. PCT1FR20061050643 dated June 28, 2006.

06Opa enet1 Signed (33) 00307 Dated Dec ber 12, 2006 b, rue Villon 69008 Lyon T61. +33 (0)4 78 00 3107 Fax +33 (0)4 78 00 29 13 Internet :www.jmnz-international.fr S.A. au Capital de 94 6006 IE SIRET 329 726 848 00016 RCS Lyon I APE 7481J/ TVA intra FR 67 329 726 848 Banque CIC Lyonnaisc de Banque 10096 1800)200024555801 08 1 Licence LI-069-96-0019 1 06parlement Traduction Translation Office 0 o I4780 3107 METHOD FOR PRODUCING CARBON POWDER AND $on INSTALLATION FOR IMPLEMENTING SAME The invention relates to the technical field of the use and regeneration of carbon based materials included in products of all types.

There are various carbon production sources, with variable grades produced. A distinction is generally made between natural graphite carbon, in deposits in the form of flecks, flakes or veins, mainly used for its refractory and lubricating properties and its high chemical resistance, and artificial carbons such as artificial graphite, animal black, charcoal, pyrocarbon, active carbon, coke and carbon black. The use of natural or artificial carbon in applications, particularly the widest variety of industrial applications, such as the use of its properties for increasing the hardness of tools, the production of tires, electrodes, moulds, crucibles, nozzles, lubricants, refractories, electrical protection or other steelmaking applications, chemical engineering, foundries, nuclear, only mentioned as non-limiting examples, is becoming considerable, due to the numerous properties of this material. For all types of carbon, the constant lies in the cost, which may be very high, ranging up to 7,500 euros per tonne for graphite carbon, and 800 to 1,400 euros per tonne for carbon black.

This demonstrates the many production sources with wide variations between the products and their costs.

The Applicant's approach has been to consider the carbon-containing products available on the market, containing carbon or carbon particles and other minerals, and to investigate the treatments that they have undergone in 2 SDpaflen1eft 2 Traduction Translation P. Office Z_ (33) 4 78 00 3107 order to adapt them to other applications. More particularly, the Applicant has focused on the production of carbon powder from carbon-containing mineral products, these products being themselves obtained, for example in a non-limiting manner, by the treatment or recycling of organic solids, particularly the recycling of treated or impregnated wood such as electrical or telephone posts, railway sleepers, and timber from demolished buildings.

The carbon-containing products, composed of carbon and other minerals, are produced for example by the implementation of the method known by the trademark "CHARTHERM" (semi-figurative) whereof the technology is defined particularly in European patent No. 772.663.

The carbon-containing products thereby obtained, composed of carbon and other minerals, such as heavy metals for example, are themselves reusable for certain applications.

In practice, such re-use(s) have little added value, because the carboncontaining products are employed as such. The Applicant optimizes the method described in patent No. EP 772 663 in an alternative, described in complementary French patent application No. 05 51335, which uses the distillation of organic solids to obtain carbon-containing products, mainly composed of carbon, constituting a secondary raw material, still comprising materials other than carbon in a certain proportion, but satisfactory for certain applications.

The Applicant's approach has been to go even further and reflect on a method for separating the carbon particles from the other mineral materials in order to produce carbon powder having a very high degree of purity of about

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Odparterent 3 Traduction Translation Office 33) 0478M3107 Qi to 99.9%, and usable as a noble secondary raw material, particularly in the applications listed above.

This approach has led the Applicant to implement a method and an installation for carrying out the said method, suitable for the production of carbon powder, from carbon-containing products, obtained for example in a non-limiting manner by the "CHARTHERM" method mentioned above, but also and, more generally, by treating mineral products incorporating a large proportion of carbon particles, for the recovery of the carbon, the noble mineral material.

According to a first feature, the method for producing carbon powder consists in the execution of the following phases: taking of a mineralized solid carbon-containing product, including carbon particles and particles of other minerals, and introduction into a grinder under pressure to crush the carbon-containing product in order to reduce the particle size, the crushing force being adjusted in order to break the structure of the carbon matrix and to liberate the other minerals from the carbon gangue which coats them while trying to preserve their initial size, and circulating of the ground products with a fluid having a transport function, removal of the carbon particles and the particles of the other minerals by pneumatic transport to a centrifugation zone (Z2) for separating the carbon from the other minerals including the heavy metals, centrifugation with separation of the carbon particles from the other minerals under the effect of their difference in density with removal of the carbon particles transported by a gaseous fluid to means for separating the E4 4 Traduction r Translation Office (33104 a 0 ~310 7 carbon particles from the transport gas, and collection of the particles of the other minerals leaving the centrifuge in a recovery tank, separation of the carbon particles from the transport gases at the centrifuge outlet in a zone the said gases being recycled, removal of the resulting carbon particles in the form of carbon powder for their storage packaging and sale, recycling of the gaseous transport fluid.

The method is described in detail in the rest of the description.

The installation for implementing the method comprises: means for feeding carbon-containing products and their transfer to a pressure grinder, means for pressure grinding the carbon-containing product provided with means for controlling the physical parameters of the said grinding, means for continuously feeding a gaseous transport fluid, for transporting the carbon particles and the particles of other minerals and for circulating the gaseous transport fluid in a continuous closed circuit until the separation of the carbon particles from the gaseous transport fluid, means for the centrifugal separation of the carbon particles from all the other mineral particles, including the heavy metals, means for separating the carbon particles from the gaseous transport fluid, means for transferring the clean carbon particles, collected in the form of carbon powder, for their packaging, means for packaging the clean carbon powder, means for recycling the gaseous transport fluid.

Upoarternent Traduction Translation I Office The installation is described in greater detail below.

These features and even others will clearly appear from the rest of the description.

The object of the invention is illustrated in a non-limiting manner in the appended figures and drawings in which: Figure 1 is a schematic view of the installation of the invention, Figure 2 is a schematic view of the pneumatic centrifuge.

To express the object of the invention in more concrete form, it is now described in a non-limiting manner illustrated in the figures and the drawings.

The solid carbon-containing products treated are based on carbon and various minerals some of which are metallic. They issue, for example, from the implementation of the "CHARTHERM" method as described in the above-mentioned European patent EP 772 663 or the French patent application No. 05 51335.

The invention relates to the treatment of these carbon-containing products, issuing from the method in its various versions, or from any other technology, for distinguishing and producing, after the extraction of the mineral particles other than carbon, carbon powder in the virtually pure state for use in various applications.

For this purpose, the installation comprises means in the form of a hopper for collecting the solid carbon-containing particles conveyed WDariemnent 6 Traduction Translation Office (331047 O317~ S thereto by conveyors and for sending them towards a first action and treatment zone (Z1) materialized by the use of a pressure grinder for example a swing frame grinder. This grinder is used to reduce the particle size of the carbon-containing product and to break the structure of the carbon matrix while trying to preserve the size of the minerals other than carbon present in the carbon-containing product, these minerals being liberated from the carbon gangue which coated them, and to obtain at the grinder outlet a particle size distribution narrowly dispersed about the mean particle size.

This grinder is equipped with the following components: a carboncontaining product feed hopper a cellular valve adjusting the inlet flow rate of the carbon-containing products in the grinder. Furthermore, the said grinder is arranged in its bottom part with a pneumatic system for recovering the products resulting from the grinding to transport them to the pneumatic separator whose function is to reduce the width of the particle size distribution issuing from the grinder and to return to the grinder the particles considered too large. The inert transport gas is introduced into the bottom part of the grinder using a blowing fan introduced into the closed air circuit and issuing from means acting as a collapsible tank. The pneumatic separator has an outlet line for circulating gas transporting the various carbon particles and other minerals.

The routing of these carbon particles and other minerals takes place via the appropriate line being transported by the gases in the predefined distribution circuit to a second zone called centrifugation zone This is arranged for separating the carbon particles from the other mineral particles including the heavy metals.

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6ppartement Traduction 7 Translation Office Z- 3(104780317 07 The pneumatic centrifuge shown in Figure 2, thereby comprises an entry (9a) for the solid particles from the grinder and transported by the gases, an outlet (9b) for the carbon particles and, internally, a deflector drum (9c) whereof the rotation causes the formation of an annular air cushion rotating on itself. Furthermore, the bottom part of the centrifuge is arranged with a recovery unit (10) for collecting the mineral particles other than carbon.

A negative pressure is created at the centre of the centrifuge by means located downstream, that is a main fan through a filter box (18) and a cyclone This negative pressure attracts the particles perpendicularly from the periphery to the centre. The heaviest particles, in other words, the particles consisting of minerals other than carbon, while passing through the air cushion formed by the rotation of the deflector drum, undergo a centrifugal acceleration, directly proportional to their mass, which diverts them from their initial trajectory and projects them to the periphery of the air cushion, towards the walls of the centrifuge. Upon contact with the wall, these particles lose their speed and fall by gravity to the bottom of the centrifuge. They are removed via a cellular valve (12) which provides the seal between the transport flow circuit and the recovery tank (10) installed under the centrifuge. The carbon particles, having a density too low to undergo the accelerating influence of the rotating air cushion, are not diverted from their trajectory and travel directly to the centre of the centrifuge.

At this stage, that is at the centre of the centrifuge, the negative pressure created by the main fan (23) entrains the carbon particles which are transported by the gaseous fluid, through the cyclone where a first separation etpartement Tradustion 8 Translation Office ZZ (33104800317 takes place between the carbon particles and the gaseous fluid. However, the experiment has shown that at the outlet of the cyclone unit, the transport gas could still convey very fine carbon particles. Thus, downstream of the cyclone unit, a complementary unit is provided, consisting of a filter box connected by the line The negative pressure created by the main fan (23) entrains the gas stream through the filter box where the second separation takes place between the carbon particles and the transport fluid.

Once it has passed through the filters, the transport gas is removed by the main fan (23) to the collapsible tank, while the carbon accumulated on the walls of the filters falls into the bottom of the filter box due to the cyclic cleaning countercurrents. The carbon particles, falling into the bottom of the cyclone after the first separation, pass through a cellular valve (16) and fall into a linear conveyor A certain mass of carbon powder is thereby obtained, which is then conveyed to a packaging system. The mass of carbon powder accumulated at the bottom of the filter box passes through a cellular unit (19) and falls into the above-mentioned linear conveyor (17).

The collapsible tank which is therefore located between the blowing fan and the suction fan (23) is conformed as a tank. As much gaseous fluid enters this collapsible tank as leaves therefrom. This fluid incorporates nitrogen (6a) for starting the operation of the installation and to maintain an inert gaseous atmosphere under negative pressure with a controlled composition.

The nitrogen is fed to the collapsible tank from a nitrogen generator not shown in the drawing. This fluid distribution circuit is therefore perfectly defined and suitable for circulating fluid in the various successive zones (Z 1, Z2, Z3) in addition to the complementary bypass (11) from the collapsible Vz5t1<b SDdpart ent radL 4ion.

r nv ZP (33)0478 07 ZZ~ t: D6 D~aement Tr uiadiOf 9 Translation Office (33) 04 78M3107 iN k//n 1 L9 tank to the centrifuge, facilitating the introduction of the particles into the centrifuge.

The line portion between the collapsible tank and the blowing fan has the reference numeral (24) and the line between the blowing fan and the grinder has the reference numeral The complete fluid circuit from the collapsible tank is defined by the line portions This circuit is a sealed closed circuit which does not communicate with the exterior. The cellular valves (12) (16) (19) seal the flow from the exterior and at the product inlets and outlets.

Subsidiarily, for controlling the flow rate of gas before the grinder a bypass (25) may be provided including a control valve (26).

The installation operates continuously.

Without going beyond the scope of the invention, the filtration apparatus downstream of the cyclone unit can be arranged with several filtration stages to further refine the capture of the carbon particles, so that the transport gas, once recycled, can be free or virtually free of any particles.

The inventive method thereby serves in a novel manner, using the recovery of mineralized organic products by methods, such as for example the "CHARTHERM" method, in its different variants, to produce carbon powder with a very high degree of purity.

The recovery of the carbon by the method thereby becomes a novel source of the treatment of carbon particles and the production of carbon SDdparle ent S Tra i on I eon p. C 33)047800 7 D partement Traduction Translation I Office (330478003107 I powder, which is positioned in largely competitive cost brackets compared with the prior art technologies for obtaining carbon.

The packaging of the carbon powder in bags is one possible mode for its distribution. Obviously, various known means can be used for the packaging, weight control, extraction of air during the bagging operation, fluidity control of the carbon powder, with the use of anti-caking systems.

The invention provides a very important advance and allows the recycling and valuable use of this noble material for other applications.

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Depar r

Claims

1. Method for producing carbon powder, characterized in that it consists in the execution of the following phases: taking of a mineralized solid carbon-containing product, including carbon particles and particles of other minerals, and introduction into a grinder under pressure to crush the carbon-containing product in order to reduce the particle size, the crushing force being adjusted in order to break the structure of the carbon matrix and to liberate the other minerals from the carbon gangue which coats them while trying to preserve their initial size, and circulating of the ground products with a fluid having a transport function, removal of the carbon particles and the particles of the other minerals by pneumatic transport to a centrifugation zone (Z2) for separating the carbon from the other minerals including the heavy metals, centrifugation with separation of the carbon particles from the other minerals under the effect of their difference in density with removal of the carbon particles transported by a gaseous fluid to means for separating the carbon particles from the transport gas, and collection of the particles of the other minerals leaving the centrifuge in a recovery tank, separation of the carbon particles from the transport gases at the centrifuge outlet in a zone the said gases being recycled, removal of the resulting carbon particles in the form of carbon powder for their storage packaging and sale, recycling of the gaseous transport fluid.

2. Installation for implementing the method according to Claim 1, characterized in that it comprises: Dpartement Traduction 12 Translation 2 Office (33) 0478 3 07 means for feeding carbon-containing products and their transfer to a pressure grinder means for pressure grinding the carbon-containing product provided with means for controlling the physical parameters of the said grinding, means for continuously feeding a gaseous transport fluid, for transporting the carbon particles and the particles of other minerals and for circulating the gaseous transport fluid in a continuous closed circuit until the separation of the carbon particles, means for the centrifugal separation of the carbon particles from all the other mineral particles, including the heavy metals, comprising a pneumatic centrifuge comprising an inlet (9a) for incoming solid particles issuing from the grinder and transported by the gases, an outlet (9b) for the carbon particles and, internally, a deflector drum (9c) whereof the rotation causes the formation of an annular air cushion rotating on itself, and in that the bottom part of the centrifuge is arranged with a recovery unit of the mineral particles other than carbon, and in that a negative pressure created at the centre of the centrifuge attracts the particles which enter the centrifuge perpendicularly from the periphery towards the centre, means for separating the carbon particles from the gaseous transport fluid, means for transferring the clean carbon particles, collected in the form of carbon powder, for their packaging, means for packaging the clean carbon powder, means for recycling the gaseous transport fluid. partenieft .413 Traduction Translation Office (33 (A18 00 31 07

3. Installation according to Claim 2, characterized in that it comprises means in the form of a hopper for collecting the solid carbon-containing particles conveyed thereto by conveyors and for sending them towards a first action and treatment zone (Z1) materialized by the use of a pressure grinder and in that the grinder is equipped with a solid carbon-containing product feed hopper a cellular valve adjusting the inlet flow rate of the solid carbon-containing products into the grinder, and in that the said grinder is arranged in its bottom part with a pneumatic system for recovering the products resulting from the grinding to transport them to the pneumatic separator

4. Installation according to Claim 3, characterized in that it comprises, in addition to the grinder, a pneumatic selector having the function of reducing the width of the size distribution of the particles leaving the grinder and of returning the particles considered too large to the grinder, and in that the pneumatic separator has an outlet line for the exit of the ground product.

5. Installation according to either of Claims 2 and 3, characterized in that the routing of the particles of different types, which are transported by the gases in a predefined distribution circuit, takes place via the line to a second zone called the centrifugation zone (Z2), and in that the said zone is arranged for separating the carbon particles from the other mineral particles including the heavy metals. Ddpartement S Traduction 14 Translation I Office I 3304 7800 3107 'i/1on

6. Installation according to Claim 5, characterized in that it comprises means forming a collapsible tank having the function of balancing the transport gas flows in the circuit.

7. Installation according to Claim 5, characterized in that a negative pressure, created at the centre of the centrifuge by the main fan through the filter box (18) and the cyclone attracts the particles entering the centrifuge perpendicularly, from the periphery to the centre.

8. Installation according to Claim 5, characterized in that the mineral particles other than carbon, having a higher density, while passing through the air cushion formed by the rotation of the deflector drum, undergo a centrifugal acceleration, directly proportional to their mass, which diverts them from their initial trajectory and projects them to the periphery of the air cushion, towards the centrifuge walls in contact with which the particles lose their speed and fall by gravity into the bottom part of the centrifuge, and in that the carbon particles having a density too low to undergo the accelerating effect of the rotating air cushion, are not diverted from their trajectory and travel directly to the centre of the centrifuge.

9. Installation according to Claim 5, characterized in that the removal of the mineral particles other than carbon is obtained by incorporating a cellular valve (12) which provides the seal between the transport flow circuit and the recovery tank (10) installed under the centrifuge.

Installation according to any one of Claims 2, 3, 5 and 8 characterized in that the fluid/carbon particles mixture issuing from the centrifuge is SDdpat ment -S Tra tion Z- \I V-~ton (:13)0478 '07 D~parlemeft .4 S Traduction Translation Office (a 33)0178003107164 conveyed into a line (13) and is sent to a cyclone unit (14) for separating the transport gas flow from the carbon particles, and in that downstream of the cyclone unit, a supplementary unit is provided consisting of a filter box connected by the line and in that the filter box, consisting of a closed chamber, provides supplementary filtration with suction of the transport gas, removed by the main fan (23).

11 I. Installation according to Claim 10, characterized in that the transport gas is removed using a line (14a) placed in the upper part of this equipment for removal via a line and in that the carbon particles of a certain density fall into the bottom of the unit (14) and are recovered using a cellular valve (16) which provides the seal between the transport flow circuit and the linear conveyor (17), and in that the carbon particles are recovered by a periodic cleaning of the filters, the carbon particles then being conveyed to the bottom of the filtration unit for removal via a cellular valve (19) which provides the seal between the transport flow circuit and the linear conveyor (17).

12. Installation according to Claim 10, characterized in that the carbon particles issuing from the cyclone unit, or from the filtration apparatus, are collected by the conveyor (17) and conveyed via supplementary transfer means such as conveyor hopper (21) to storage means (22) such as a bag or other.

13. Installation according to Claim 10, characterized in that the gaseous fluid now free of carbon particles is removed from the filtration apparatus (18) by another line (28) which is connected to the collapsible tank, a suction fan (23) and fluid flow accelerator facilitating the recycling of the fluid, D 16 TraduCtion B Translation Ofce O~ o (334803107 and in that the suction fan (23) participates in the operation of the fluid transport circuit by facilitating and permitting the suction of the gases through the filter box and the cyclone, thereby creating a negative pressure at the centre of the centrifuge.

14. Installation according to Claim 3, characterized in that the collapsible tank situated between the blowing fan and the suction fan is conformed as a tank into which as much gaseous fluid enters as leaves, and in that the fluid incorporates nitrogen for starting the operation of the installation and for maintaining an inert gaseous atmosphere under overpressure with a controlled composition in the gas circuit.

Installation according to any one of Claims 2 to 14, characterized in that the complete fluid circuit, from the collapsible tank, is defined by the line portions (28), and in that the circuit is a sealed closed circuit which does not communicate with the exterior, the cellular valves (12) (16) (19) sealing the flow from the exterior and at the product inlets and outlets.

16. Installation according to Claim 15, characterized in that, for controlling the fluid flow rate before the grinder a bypass (25) may be provided including a control valve to adjust the flow rate of gaseous fluid injected into the pressure grinder. DO are lent sj Tr u on on (33) 78 3 07 n