Process for recycling li-ion batteries

Abstract

The present invention concerns a process for the recovery of metals and of heat from spent rechargeable batteries, in particular from spent Li-ion batteries containing relatively low amounts of cobalt. It has in particular been found that such cobalt-depleted Li-ion batteries can be processed on a copper smelter by: feeding a useful charge and slag formers to the smelter; adding heating and reducing agents; whereby at least part of the heating and/or reducing agents is replaced by Li-ion batteries containing one or more of metallic Fe, metallic Al, and carbon. Using spent LFP or LMO batteries as a feed on the Cu smelter, the production rate of Cu blister is increased, while the energy consumption from fossil sources is decreased.

Claims

1. A process for the recovery of enthalpy and metals from Li-ion batteries, comprising: feeding a charge and slag formers to a copper smelter, wherein the charge comprises a copper-bearing feed; and adding heating and reducing agents; wherein at least part of the heating and/or reducing agents is replaced by Li-ion batteries containing one or more of metallic Fe, metallic Al, or carbon.

2. The process according to claim 1, wherein the slag formers comprise SiO.sub.2 in an amount sufficient to comply with 0.5<SiO.sub.2/Fe<2.5 and with Al.sub.2O.sub.3<10 wt. % in the formed slag.

3. The process according to claim 1, wherein more than 50% of the Li-ion batteries contain 3 wt. % of Co or less.

4. The process according to claim 2, further comprising adjusting the amount of Li-ion batteries fed to the copper smelter in order to obtain an amount of Co in the formed slag of less than 0.1 wt. %, wherein more than 50% of the Li-ion batteries contain 3 wt. % of Co or less.

Description

EXAMPLE 1: REFERENCE CHARGE WITHOUT BATTERIES

(1) A typical charge for the smelter is shown in Table 2 below.

(2) TABLE-US-00002 TABLE 2 Reference charge of Cu smelter (wt. %) Feed rate (t/h) Li S Ni Mn Co Fe Cu Al Al.sub.2O.sub.3 SiO.sub.2 100 (Reference) 18 0.6 20 25 1 15 23.2 (Flux) 100

(3) The balance of the reference charge (20%) is moisture. A SiO.sub.2/Fe ratio 2.2 is maintained by addition of silica (23.2 ton/h), while Al.sub.2O.sub.3 is kept below 6% in the slag. At a feed rate of 100 ton/h, 18% of this feed is converted to Cu blister, 60% to slag, with the gases (mainly SO.sub.2) closing the material balance.

(4) The fuel consumption amounts to 3000 l/h, together with 18000 Nm.sup.3/h oxygen.

EXAMPLE 2: REFERENCE CHARGE INCLUDING LFP BATTERIES

(5) A charge including LFP batteries and additional flux is shown reported in Table 3 below.

(6) TABLE-US-00003 TABLE 3 Reference charge including LFP batteries and additional flux (wt. %) Feed rate (t/h) Li S Ni Mn Co Fe Cu Al Al.sub.2O.sub.3 SiO.sub.2 100 (Reference) 18 0.6 20 25 1 15 17.6 (Batteries) 1 15 25 10 29.0 (Flux) 100

(7) A SiO.sub.2/Fe ratio of 2.2 is maintained by adding of 5.8 t/h of SiO.sub.2, with respect to the reference case. Al.sub.2O.sub.3 is kept below 6% in the slag by limiting the amount of added LFP batteries to 17.6 t/h. This corresponds to a yearly capacity of about 60000 tons of batteries, which is appreciable in view of the quantities of spent batteries of this type presently available on the market.

(8) Using spent batteries as a feed on the Cu smelter, the production rate of Cu blister is thus increased with more than 20%, while hazardous waste is being recycled. Of course, this is dependent upon the relative amounts of Cu present in the reference smelter charge and in the spent batteries.

(9) Due to the high calorific value of the LFP battery feed and to the battery-related Cu being present as metal instead of as oxidized species, the fuel consumption can be decreased from 3000 l/h to 2000 l/h, while the oxygen consumptions rises from 18000 Nm.sup.3/h to 20000 Nm.sup.3/h to maintain the furnace heat balance. This is a reduction of more than 30% of the energy consumption from fossil sources.