Plant for the disposal of lithium batteries and recovery of lithium

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)+NaCO3+heat→Li2CO3(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).