PLANT FOR THE DISPOSAL OF LITHIUM BATTERIES AND RECOVERY OF LITHIUM

Abstract

Plant for disposing and recovering lithium batteries, including: storage; supply; crushing, submerged in liquid solution and in overpressure of inert gas, for destroying the batteries through cutting discs and milling cutters; torch for burning the gaseous residue and possible organic solvents; centrifugation and screening of the scrap; evaporation, for removing the volatile solvents and concentrating the lithium in solution; recovery of the heavy metals, with chemical/physical reactor which, by way of a filter press, distributes the products between a liquids tank and a solids tank; recovery of lithium wherein the lithium is recovered through the crystallisation of lithium carbonate by adding sodium carbonate and heating, contained in a tank and heating the solution in a special heated tank, in a chemical/physical reactor.

Claims

1. Plant for the disposal of lithium batteries and recovery of lithium, comprising at least the following technical areas: storage area (10), arranged upstream of the entire plant, protected against atmospheric agents and waterproofed, in which lithium batteries and accumulators to be disposed are discharged; supply plant (20), provided with a forklift suitable to discharge the accumulated batteries into a loading hopper from which they are conveyed to a crushing area (30) provided with a crusher submerged in a liquid solution or in an inert atmosphere coming from a special tank (38) and submerged in the crusher by means of a common dosing pump (38′); said crusher being suitable to mechanically destroy the submerged batteries by means of cutting discs (32) and milling cutters connected to an equal number of drive shafts (31); said crusher also being provided with at least one grid (33) with mesh comprised between 10 mm and 35 mm suitable to enable the control of the grain size of the solid residues; said crushing area (30) being suitable to operate in overpressure with respect to the external environment and in an inert atmosphere due to the presence of a hydrostatic head and pressure sensors, connected to insufflation valves (39′) connected to at least one tank (39) for inert gas, so as to keep the pressure value within pre-established threshold values; said crushing area (30) being also provided, above said crusher, with at least one purifier (35) suitable to treat the gases emitted by the crushing process impacting them with a flow of water alkalized with sodium hydroxide in counter-current, so as to absorb the gases and the inorganic acids and the possible solvent vapours, reducing the risk of emissions into the atmosphere and conveying the remaining gases flowing out from said purifier (35) to a combustion device (40), positioned outside the structure of the crushing area (30) suitable to burn the combustible gaseous residue of the crushing; a scrap screening area (70), positioned downstream of a discharge auger or a touch chain (36) which collects the scrap deriving from the crushing, provided with a common centrifuge for eliminating process water and a common distribution system (71) suitable to distribute said scrap, based on their characteristics, among a plurality of containers (72-72′-72″) for the subsequent recovery operations; another part of the solid component, resulting from the crushing, instead being conveyed in a filter (34) followed by a recycling pump (34′) suitable to push the residues towards a filter for eliminating solids (45) in turn suitable to distribute the received material between an evaporation area (50) and an area for recovering heavy metals (55); said evaporation area (50), suitable to collect the water containing organic solvents and lithium diluted in solution and perform a semi-discontinuous vacuum evaporation to remove the volatile solvents and concentrate the lithium in solution; said evaporation area (50) being provided with at least one evaporator (51) with a system for recirculating the vapour (51′) connected to at least one tank of the concentrated product (52), in turn connected to a lithium treatment and recovery area (60) and a tank for the evaporated product (54), by means of a common vacuum pump (53); said heavy metals recovery area (55), suitable to collect the process water flowing out from the crushing area (30) for removing the solid particles that are larger than a pre-established threshold; said heavy metals recovery area (55) being provided with at least one chemical/physical reactor with stirrer (56) which, through a filter press (57), is suitable to distribute the obtained products between a liquid waste tank (58) and a solids tank (59) containing the heavy metals to be disposed; said lithium recovery area (60) in which lithium was recovered by crystallising lithium carbonate by adding sodium carbonate, contained inside a tank (65) and heating the solution coming from said evaporation area (50) in a special tank (64) heated up to a temperature of about 60° C., according to the following precipitation reaction:
2 (OH)+NaCO.sub.3+heat.fwdarw.Li.sub.2CO.sub.3(s)+2 Na(OH)  said reaction occurring in a chemical/physical reactor with stirrer (61); the waste products exiting from said lithium recovery area (60) being distributed between a liquids tank (63) and a lithium dryer (62).

2. The plant for the disposal of Lithium batteries and recovery of lithium, according to claim 1, wherein the plant enables the recovery of lithium at a degree of purity according to at least one of the following technical standards, pharmaceutical standards or similar standards: BP (British Pharmaceutical) whose specifications are as follows: Li.sub.2CO.sub.3—73.9—554-13-2; content: 98.5% to 100.5%; appearance: white or almost white powder; solubility: slightly soluble in water, practically insoluble in 96% ethanol; USP (United States Pharmaceutical), whose specifications are as follows: Li.sub.2CO.sub.3—73.89; carbonic acid, dilithium salt; dilithium carbonate—[554-13-2] containing not less than 99.0% of Li.sub.2CO.sub.3, calculated on the dried base.

3. The plant for the disposal of Lithium batteries and recovery of lithium, according to claim 1, further comprising at least one analysis laboratory (100) provided with all analytical equipment and suitable for analysing the process and the degree of purity of the recovered lithium; said analysis laboratory (100) being suitable to verify whether the recovered lithium meets the parameters that enable the selling thereof, possibly in the pharmaceutical industry too; said analysis laboratory (100) also being provided with an area for preparing the sample and storing the reagents and with at least one station for analysing and storing the process data.

4. The plant for the disposal of Lithium batteries and recovery of lithium, according to claim 3, wherein downstream of said analysis laboratory (100) a common weighing and packaging installation (110) suitable to package a predetermined amount of lithium carbonate suitable to be sold and intended to be placed in the market is provided.

5. The plant for the disposal of Lithium batteries and recovery of lithium, according to claim 3, further comprising a plurality of waste storage areas, all positioned in sheltered areas, away from atmospheric agents, including at least: a solid waste storage area suitably configured to avoid any possibility of the content spilling; a treatment intermediate process water storage area, provided with special tank provided with level sensors and booster pumps; a lithium carbonate storage area suitable to collect the packaged products, exiting from said analysis laboratory 100 and meant to be sold.

6. The plant for the disposal of Lithium batteries and recovery of lithium, according to claim 1, further comprising a monitoring cabin (90) arranged upstream of said torch (40) provided with an extractor suitable to divert the flow of at least one part of the gases directed towards said torch (40) to enable the analysis of the composition of said gases; said monitoring cabin (90) being provided with at least one analyser consisting of at least one multi-parameter unit of the FT-IR (Fourier Transform Infra Red) type and a specific unit for the TOC (Total Organic Carbon) suitable to respectively analyse gases and inorganic acids and volatile solvents possibly present in said gas directed towards said torch (40).

7. The plant for the disposal of Lithium batteries and recovery of lithium, according to claim 1, wherein said storage area (10) is divided into at least two compartments into which the waste is alternatively discharged for storage according to the “First In-First Out” criterion.

8. The plant for the disposal of Lithium batteries and recovery of lithium, according to claim 1, wherein said storage area (10) and said crushing area (20) are separated by a fire and explosion-proof partitioning system which is traversed by the supply line (20) only.

9. The plant for the disposal of Lithium batteries and recovery of lithium, according to claim 1, wherein said crushing area (30) is provided with a foam discharge system (37) and an alternating current asynchronous electric motor, suitable to drive said drive shafts (31), arranged outside the submerged portion of said crushing area (30).

10. The plant for the disposal of Lithium batteries and recovery of lithium, according to claim 1, wherein the plant is suitable for destroying and disposing, with recovery of lithium, all types of lithium batteries and accumulators, irrespective of the operating technology.

11. The plant for the disposal of Lithium batteries and recovery of lithium, according to claim 1, wherein said combustion device (40) is a torch or a fuel cell for producing electric power starting from hydrogen coming from the crushing process and atmospheric oxygen or synthesis process.

12. The plant for the disposal of lithium batteries and recovery of lithium of claim 1, wherein the at least one tank for inert gas contains nitrogen; and the pre-established threshold values for pressure value are 20 mBars and 120 mBars.

13. The plant for the disposal of Lithium batteries and recovery of lithium, according to claim 2, characterised in that it comprises at least one analysis laboratory (100) provided with all analytical equipment and suitable for analysing the process and the degree of purity of the recovered lithium; said analysis laboratory (100) being suitable to verify whether the recovered lithium meets the parameters that enable the selling thereof, possibly in the pharmaceutical industry too; said analysis laboratory (100) also being provided with an area for preparing the sample and storing the reagents and with at least one station for analysing and storing the process data.

14. The plant for the disposal of Lithium batteries and recovery of lithium, according to claim 5, wherein the special tanks are made of concrete.

15. The plant for the disposal of Lithium batteries and recovery of lithium, according to claim 4, further comprising a plurality of waste storage areas, all positioned in sheltered areas, away from atmospheric agents, including at least: a solid waste storage area suitably configured to avoid any possibility of the content spilling; a treatment intermediate process water storage area, provided with special tanks provided with level sensors and booster pumps; a lithium carbonate storage area suitable to collect the packaged products, exiting from said analysis laboratory 100 and meant to be sold.

16. The plant for the disposal of Lithium batteries and recovery of lithium, according to claim 2, further comprising a monitoring cabin (90) arranged upstream of said torch (40) provided with an extractor suitable to divert the flow of at least one part of the gases directed towards said torch (40) to enable the analysis of the composition of said gases; said monitoring cabin (90) being provided with at least one analyser consisting of at least one multi-parameter unit of the FT-IR (Fourier Transform Infra Red) type and a specific unit for the TOC (Total Organic Carbon) suitable to respectively analyse gases and inorganic acids and volatile solvents possibly present in said gas directed towards said torch (40).

17. The plant for the disposal of Lithium batteries and recovery of lithium, according to claim 3, further comprising a monitoring cabin (90) arranged upstream of said torch (40) provided with an extractor suitable to divert the flow of at least one part of the gases directed towards said torch (40) to enable the analysis of the composition of said gases; said monitoring cabin (90) being provided with at least one analyser consisting of at least one multi-parameter unit of the FT-IR (Fourier Transform Infra Red) type and a specific unit for the TOC (Total Organic Carbon) suitable to respectively analyse gases and inorganic acids and volatile solvents possibly present in said gas directed towards said torch (40).

18. The plant for the disposal of Lithium batteries and recovery of lithium, according to claim 4, further comprising a monitoring cabin (90) arranged upstream of said torch (40) provided with an extractor suitable to divert the flow of at least one part of the gases directed towards said torch (40) to enable the analysis of the composition of said gases; said monitoring cabin (90) being provided with at least one analyser consisting of at least one multi-parameter unit of the FT-IR (Fourier Transform Infra Red) type and a specific unit for the TOC (Total Organic Carbon) suitable to respectively analyse gases and inorganic acids and volatile solvents possibly present in said gas directed towards said torch (40).

19. The plant for the disposal of Lithium batteries and recovery of lithium, according to claim 5, further comprising a monitoring cabin (90) arranged upstream of said torch (40) provided with an extractor suitable to divert the flow of at least one part of the gases directed towards said torch (40) to enable the analysis of the composition of said gases; said monitoring cabin (90) being provided with at least one analyser consisting of at least one multi-parameter unit of the FT-IR (Fourier Transform Infra Red) type and a specific unit for the TOC (Total Organic Carbon) suitable to respectively analyse gases and inorganic acids and volatile solvents possibly present in said gas directed towards said torch (40).

20. The plant for the disposal of Lithium batteries and recovery of lithium, according to claim 2, wherein said storage area (10) is divided into at least two compartments into which the waste is alternatively discharged for storage according to the “First In-First Out” criterion.

Description

DESCRIPTION OF THE FIGURES

[0055] The invention will be described hereinafter in at least one preferred embodiment, provided by way of non-limiting example, with reference to the attached figures, wherein:

[0056] FIG. 1 shows a general diagram of the plant subject of the present invention identified in which are macro areas, i.e.: the storage area 10, the supply 20, the crushing area 30, the torch 40 (or alternatively the cell fuel), the evaporation area 50, the Lithium recovery area 60, the heavy metals recovery area 55, the scrap material screening and centrifugation area 70 the monitoring cabin 90.

[0057] FIG. 2 illustrates more in detail the submerged crushing area 30 shown in which are four shafts 31 connected to cutting discs 32. Arranged downstream of the machine, or after grinding, is a grid 33 with pre-stablished mesh-size so as to allow the passage, downstream, of the ground pieces that do not exceed a given size.

[0058] FIG. 3 shows an operating diagram of the purifier 35 suitable to absorb inorganic acids and gases and vapours of solvents.

[0059] FIG. 4 shows a closer view of the torch 40 for the combustion of the hydrogen resulting from the crushing of the batteries.

[0060] FIG. 5 shows the evaporation area 50 in which an evaporator 51 provided with a system for the recirculation of vapour 51′ connected to a boiler (not represented) or with electric heating and suitable to sort the obtained products between a tank for the concentrated product 52, which will be conveyed to the treatment and recovery area 60, and a tank for the evaporated product 54, by means of a common atex vacuum pump 53.

[0061] FIG. 6 shows a Lithium recovery area 60 converging in which, in the chemical/physical reactor with stirrer and heating 61, are the Na.sub.2CO.sub.3 solution from a dedicated tank 65 and the waste liquid of the evaporation process (evaporation area 50) contained in a heated tank 64. From here, the waste products are sorted between a liquids tank 63 and a Lithium dryer 62 in turn connected to the analysis laboratory 100 and to the relative weighing and packaging installation 110 for re-introduction into the market.

[0062] FIG. 7 illustrates the area for screening the scrap material 70 coming from the auger 36 for discharging the crushing area 30. Here, a waste separation plant 71 sorts the received material into a plurality of containers 72-72′-72″ distinguishing them according to the type of waste.

[0063] FIG. 8 shows, more in detail, the heavy metals recovery area 55 in which a chemical/physical reactor with stirrer 56, by means of a filter press 57, sorts the obtained products between a waste liquids tank 58 and a solids tank 59 containing the heavy metals meant for recovery.

DETAILED DESCRIPTION OF THE INVENTION

[0064] Now, the present invention will be illustrated purely by way of non-limiting or non-binding example, with reference to the figures illustrating some embodiments regarding the present inventive concept.

[0065] Shown with reference to FIG. 1 is the general diagram of the plant for the disposal of batteries and recovery of Lithium subject of the present invention.

[0066] The storage area 10, upstream of the plant, must be protected against atmospheric agents and made waterproof. The storage area 10 will be divided into at least two compartments into which the waste will be alternatingly discharged for storage according to the “First In-First Out” criterion. The area can be provided with fire safety measures (partitioning and suffocation systems) in order to reduce fire risks.

[0067] The supply system 20, in which a forklift will preferably discharge the batteries accumulated in a loading hopper, starts from the storage area 10. The batteries will then be transferred into the crushing area 30 using a common conveyor belt.

[0068] The crushing area 30 is pivoted around a crusher better represented in FIG. 2. The physical opening of the batteries occurs here and, in order to avoid the risk of explosion and thus triggering fire, all opening activities are carried out in a submerged fashion and in controlled atmosphere. The liquid solution is stored in a special tank 38 and supplied to area 30 by means of a common dosing pump 38′. The plant is also provided with a foam discharge system 37. In this case, the crusher consists of four shafts 31 with cutting discs 32 (discs with sharp edges provided with hooks). Each hook that the cutting discs 32 are provided with has the purpose of hooking the product and conveying it towards the milling cutters also mounted on the counter-rotating drive shafts 31 which cut the material decisively. The system is provided with an alternating current asynchronous electric motor arranged outside the submerged crushing area. Present downstream of the milling cutters is a grid 33 with mesh-size comprised between 10 mm and 35 mm which allows to control the grain size of the residues. The largest residues can be possibly returned upstream so as to undergo the crushing process just described above once again.

[0069] As previously illustrated, due to safety reasons the crushing area 30 operates under slight overpressure so as to prevent the inflow of oxygen. Thanks to the presence of hydrostatic head, the internal pressure of the cutting area can be brought to a preferred value of 120 mBars. Suitable pressure sensors, connected to insufflation valves 39′ and connected to a nitrogen tank 39, will keep the pressure value within the pre-established threshold values. Should the desired pressure be exceeded, the surplus gas will gurgle through the inlet duct, thus preventing the apparatus from exploding. Should the pressure drop excessively, the valves 39′ will insufflate new nitrogen so as to keep the parameter within the safety values that will make the environment fully inert.

[0070] Advantageously positioned above the submersion area is a purifier 35 better illustrated in FIG. 3 which is suitable to treat the gases emitted by the crushing process impacting them with a flow of alkaline water with sodium hydroxide (whose pH is higher than 10) against the current. Said purifier 35 will allow to absorb the inorganic gases and acids and possible solvents, thus reducing the risk of emissions.

[0071] All the produced hydrogen is sent to the burning carried out by a torch 40 like the one represented in FIG. 4 or, if the degree of purity is sufficiently high, to energy recovery in a fuel cell, arranged outside the structure of the crushing area 30. In order to monitor the chemical composition of the gas flowing into the torch 40 (given the impossibility to analyse the outflowing gas) and thus in order to verify the correct operation of the purifier 35 and hence nullifying harmful emissions, positioned downstream of the torch 40 is an extractor which sends part of the transiting gas to a monitoring cabin 90. The latter is provided with an analyser consisting of at least one multi-parameter unit of the FT-IR (Fourier Transform Infra Red) type and a specific TOC (Total Organic Carbon) unit for analysing inorganic gases and acids and volatile solvents respectively.

[0072] Returning downstream of the crushing area 30, the solid component of the residues falls towards a discharge auger 36 which transfers it to the scrap screening area 70 represented in FIG. 7. The scrap material coming from the grinding, commonly referred to as “black mass” is subjected to centrifugation to remove the water containing lithium and screened by a common sorting system 71 and divided according to the characteristics between a plurality of container 72-72′-72″ for the subsequent recovery operations. Components containing high value metals will selected from these fractions.

[0073] The solid component in suspension, resulting from the crushing, that does not fall into the auger 36, is instead sent to a filter 34 followed by a recycling pump 34′. From here, part of the solid components is re-introduced into the crushing area 30 so as to be subjected to a new mincing and another part is conveyed towards a filter for eliminating solids 45 which sorts the received material between an evaporation area 50 and a heavy metals recovery area 55.

[0074] The heavy metals recovery area 55 (FIG. 8) collects the process water flowing out from the crushing 30 which must be filtered to remove the solid particles with size greater than a pre-established threshold, for example 100 □m. A chemical/physical reactor provided with a stirrer 56, by means of a filter press 57, sorts the obtained products between a liquid waste tank 58 and a solids tank 59 containing the heavy metals to be disposed. Some precious metal to be sent to recovery could be present between the solid material, while the filtered water is stored and subsequently sent to the evaporation area 50.

[0075] The evaporation area 50 collects water containing organic solvents and diluted Lithium in solution. It is suitable to carry out a semi-discontinuous under vacuum evaporation to remove the volatile solvents and concentrate the Lithium in solution. The operating diagram thereof is represented in FIG. 5 which shows an evaporator 51 provided with a vapour recirculation system 51′ connected to a boiler (not represented). The evaporator 51 needs steam for supplying evaporation energy to the system, hence the plant must be provided with an appropriate generator. The product flowing into the evaporation area 50 is substantially sorted half between “evaporated” and “concentrated” conveying the outflowing product, alternatively into a concentrated product tank 52, in turn connected to a treatment and recovery area 60, and an evaporated product tank 54, by means of a common vacuum pump 53.

[0076] The Lithium recovery area 60 (FIG. 6) is the one in which the precipitation reaction occurs:

2 L(OH)+NaCO.sub.3+heat.fwdarw.Li.sub.2CO.sub.3(s)+2 Na(OH)

[0077] Following concentration, the evaporation process waste liquid (evaporation area 50) contained in a heated tank 64, is transferred to heated chemical/physical reactor and with stirrer 61 where the aforementioned reaction occurs by adding concentrated sodium carbonate (Na.sub.2CO.sub.3) coming from a special tank 65 and at a temperature higher than 60° C.

[0078] The waste products of the Lithium recovery area 60 are sorted between a liquids tank 63 and a Lithium dryer 62 in turn connected to the analysis laboratory 100 and to the relative weighing and packaging installation 110 for re-introduction of Lithium into the market according to pre-established purity parameters (BP or USP).

[0079] Said analysis laboratory 100 has all the analysis equipment required for analysing the process and finished product. Present is also an area for preparing the sample and storing the reagents as well as at least one data analysis and storage station.

[0080] All areas for the storage of solid waste coming from the aforementioned processing are suitably configured to avoid any possible spilling of the content and they are positioned in sheltered areas.

[0081] The storage of treatment intermediate water instead provides for providing special tanks, preferably made of concrete, provided with level sensors and booster pumps;

[0082] Lastly, the packaged products, exiting from said analysis laboratory 100 and meant to be sold will be collected in a Lithium Carbonate storage area.

[0083] Lastly, it is clear that the invention described up to now may be subjected to modifications, additions or variants obvious to a man skilled in the art, without departing from the scope of protection outlined by the attached claims.