Method for reclaiming active material from a galvanic cell, and an active material separation installation, particularly an active metal separation installation
A method for retrieving active material from a galvanic cell is provided. The galvanic cell includes an active material, a support for the active material and a binder for bonding the active material and the support. The method includes the following steps: (a) crushing the cells, in particular under inert gas or in a vacuum, so that solid cell fragments are also formed, (b) heating the solid cell fragments up to the decomposition temperature (T z ), which is high enough to make the binder decompose so that it loses its binding properties, preferably under inert gas or in a vacuum, such that heat treated cell fragmented are formed, and (c) classifying the heat treated cell fragments, whereby (d) the classifying comprises air jet sieving and (e) the air jet sieving is carried out in such a way that the active material is separated from the support.
1. A method for retrieving active material from a galvanic cell, wherein the galvanic cell comprises an active material, a support for the active material and a binder for bonding the active material and the support, comprising the steps of:
(a) crushing the galvanic cell, under inert gas or in a vacuum, to form solid cell fragments,
(b) heating the solid cell fragments up to a decomposition temperature, which is high enough to make the binder decompose so that the binder loses its binding properties to form heat treated cell fragments, and then
(c) separating the active material from the support by classifying the heat treated cell fragments by means of an air jet sieve,
wherein a collision of the active material and support with a sieve and/or baffle plate of the air jet sieve causes the the separation of the active material from the support.
2. The method according to claim 1 , wherein
the active material of the galvanic cell is formed of particles, and
the air jet sieve has a mesh size that is up to 200 times a specified diameter, wherein the specified diameter corresponds to a diameter which is larger than the diameter of 90% of all particles and which is smaller than the diameter of 10% of all particles.
3. The method according to claim 2 , wherein the mesh size of the sieve is a maximum of 200 μm.
4. The method according to claim 1 , wherein the galvanic cell comprises at least one anode and at least one cathode, wherein the at least one anode and at least one cathode are heated up together and wherein the resulting heat treated cell fragments are classified together in the same air jet sieve.
5. The method according to claim 1 , further comprising the steps of:
drying the solid cell fragments at a drying temperature to form dry cell fragments and drying vapours and
at least partly condensing the drying vapours to retrieve electrolyte solvents
before heating the solid cell fragments up to the decomposition temperature.
6. The method according to claim 1 , wherein the heating of the solid cell fragments up to the decomposition temperature takes place under inert gas or in a vacuum.
7. The method according to claim 5 , further comprising the steps of:
treating the dry cell fragments by means of magnetic separation to form iron-free cell fragments, and
classifying the iron-free cell fragments.
8. The method according to claim 1 , wherein the galvanic cell comprises an electrolyte and at least a portion of the electrolyte is removed during crushing of the galvanic cell under inert gas.
9. The method according to claim 1 , wherein the crushing of the galvanic cell is carried out in such a way that the median diameter of the solid cell fragments does not fall below 200 μm.
10. The method according to claim 1 , wherein the binder evaporates at the decomposition temperature.