The present invention relates to a process for recovery and recycling of cobalt sulphate from waste lithium ion batteries. More particularly, it relates to recycling of lithium ion-based batteries that have been discarded and not in use to extract cobalt sulphate from them for its reuse for various industrial processes.
BACKGROUND OF THE INVENTION
Lithium-ion batteries (LiBs) are most commonly used in several electrochemical power sources in mobiles, cameras, laptops, computers, and other advanced appliances as they are having desired size and weight, high energy density, high cell voltage, self-discharge rate, and high performance. The increased used is also associated with the huge e-waste of LiBs which is associated with major challenges for its disposal which further results in depletion of nonferrous metals, such as cobalt, and nickel. Therefore, there is need of a process for recycling these spent LiBs to obtain the depleting materials and which helps in cleaning the environment.
For the recovery of several metals including cobalt, nickel, etc several physical and chemical process are widely used involving crushing, dismantling, sieving, acid leaching, solvent extraction, chemical precipitation and electrochemistry. These processes are involved with several defects including generation of hazardous gases, dust emissions, huge energy consumption and material loss. Also, a hydrometallurgical process provides an alternative for recycling of spent batteries into pure metals or metal salts with low energy requirement and produce salts as by-products.
US5447552 relates to a hydrometallurgical process for the recovery of metals for the recovery and separation of nickel and/or cobalt by liquid-liquid extraction from aqueous solutions derived from the acid leaching of ores.

WO1997030181A1 relates to a process for the selective extraction of cobalt from an aqueous feed solution containing cobalt, in the presence of one or more other metals, especially nickel, which comprises contacting the feed solution with an extractant comprising an amidobis (thiophosphoryl) compound.
WO2002022897A1 relates to a method of separating cobalt and nickel from other elements contained in an aqueous leach solution by adding a precipitating agent to the aqueous leach solution to precipitate elements including cobalt and nickel; separating and leaching the precipitate with an acid to form a leach liquor; and subjecting the leach liquor to successive solvent extraction steps with an organophosphoric acid and an organophosphinic acid.
However, methods for recycling of LiBs heretofore known suffer from a number of disadvantages including that the existing methods have low values for recovery of the LiBs salts including cobalt sulphate and utilization of by¬products, direct acid leaching of ores or concentrates using sulfuric acid have been largely unsuccessful, needs high pressure and high temperature, solution purification is needed to separate cobalt from zinc, the recycled LiBs are too heavy, the transportation and the disassembly are inconvenient, the next recycling is inconvenient, and the inside of the recycled LiBs generates moisture.
Accordingly, there is a need for an approach that resolves problems of state of art to provide a simple process for recovery and recycling of salts including cobalt sulphate from LiBs. For extraction of cobalt sulphate salt from LiBs a reactor, filtration techniques, potential hydrogen balances, evaporation techniques and crystallizers need to be optimised during the hydrometallurgical process to provide a method which is convenient, easy to process and with lucid steps to follow with proper safety.

OBJECT OF THE INVENTION
The main object of the present invention is to provide a process for recovery and recycling of cobalt sulphate from waste lithium ion batteries (LiBs) for its reuse for various industrial processes.
Another object of the present invention is to provide a process for extraction of cobalt sulphate from waste lithium ion batteries (LiBs) comprising the steps of shredding of waste batteries into crushed lithium ion battery pieces /leaf, and recovery of cobalt sulphate by hydro metallurgy process.
Still another object of the present invention is to provide a process for extraction of cobalt sulphate from waste lithium ion batteries (LiBs) by optimising filtration techniques, potential hydrogen balances, a reactor, evaporation techniques and crystallizers during the hydro metallurgical process to provide a method which is convenient, easy to process and with lucid steps to follow with proper safety.
SUMMARY OF THE INVENTION
The present invention relates to recycling of lithium ion batteries (LiBs) that have been discarded and not in use to extract cobalt sulphate from lithium ion batteries (LiBs) for its reuse for various industrial processes.
In a preferred embodiment, the present invention provides a process for recovery of cobalt sulphate from waste lithium ion batteries (LiBs) comprising the steps of shredding the batteries to crushed lithium ion battery pieces/leaf which is further processed by a hydrometallurgical process to obtain cobalt sulphate salt.
In another preferred embodiment, the present invention provides a process for recovery of cobalt sulphate salt from waste lithium ion batteries (LiBs) comprising the steps of: a) crushing the waste lithium ion batteries into

pieces/leafs which are processed with chemicals including but not limited to sulphuric acid, hydrogen peroxide and demineralised water in reactor at 90°C for four hours in a reactor unit to provide a slurry of reaction mixture; b) filtering the slurry of reaction mixture obtained in the step a) to obtain a filtrate and subjecting said filtrate for further processing; c) feeding the filtrate obtained in the step b) to reactor wherein pH of the solution is adjusted ranging between 3 to 4 using sodium hydroxide w/v; d) filtering the pH adjusted solution obtained in the step c) to receive a cake; e) feeding the cake obtained in the step d) to reactor for further processing with potassium permanganate to form a solution; f) filtering the solution obtained in the step e) to obtain a cake of residue and to obtain a filtrate; g) feeding the filtrate obtained in the step f) again in to the reactor and adjusting pH of a solution ranging between 5 to 6; h) feeding the solution obtained in the step g) further for filtration to obtain a filtrate; i) processing of the filtrate obtained in the step h) by increasing pH of a solution ranging between 11 to 11.5; j) filtering the solution obtained in the step i) and distributing a filtrate into two streams for further salt conversion and to obtain a cake of residue; k) processing the cake obtained in the step 1) in reactor for changing pH ranging between 3 to 4 of a solution using sulphuric acid; m) filtering the solution obtained in the step k) for further processing of a filtrate; n) elevating pH of the filtrate obtained in the step 1) ranging between 5 to 6 using ammonia for further chemical processing; o) executing a layer separation in a separating funnel through a (bis/2,4,4-trimethylpentyl/phosphinic acid) to obtain a top and a bottom layer; p) reducing volume of the bottom layer obtained in the step n) in evaporator; q) reducing the volume further for formation of crystals which settle at the bottom of a surface; and r) processing of the top layer obtained in the step n) by feeding to crystallizer to obtain cobalt sulphate with the recovery of around 3.0 kg - 6.0 kg of cobalt sulphate from 8 kg powder of lithium ion battery.

The present invention provides a method for recovery of cobalt sulphate and recycling of waste lithium ion batteries for its reuse in several industrial processes. For the extraction of cobalt sulphate from lithium ion batteries (LiBs) a reactor, filtration techniques, potential hydrogen balances, evaporation techniques, and crystallizers are optimised during the hydrometallurgical process to provide a method which is convenient, easy to process and with lucid steps to follow with proper safety.
The above objects and advantages of the present invention will become apparent from the hereinafter set forth brief description of the drawings, detailed description of the invention, and claims appended herewith.
BRIEF DESCRIPTION OF THE DRAWINGS
A complete understanding of a process for recovery of cobalt sulphate salt from waste lithium ion batteries of the present invention may be obtained by reference to the following drawings:
Figure 1 elucidates a flowchart of extraction of cobalt sulphate salt from waste lithium ion batteries (LiBs).
Figure 2 depicts an extracted cobalt sulphate salt obtained from waste lithium ion batteries (LiBs).
DETAILED DESCRIPTION OF THE INVENTION
The present invention will now be described more fully hereinafter. This invention may, however, be embodied in many different forms and should not be construed as being limited to the embodiment set forth herein. Rather, the embodiment is provided so that this disclosure will be thorough, and will fully convey the scope of the invention to those skilled in the art.

The present invention relates to recycling of LiBs that has been discarded and not in use to extract cobalt sulphate salt from them for its reuse for various industrial processes.
In a preferred embodiment, the present invention provides a process for recovery of cobalt sulphate salt from waste lithium ion batteries comprising the steps of crushing the batteries to crushed lithium ion battery pieces /leaf which is further processed by hydrometallurgical process to obtain cobalt sulphate salt.
Referring to Figure 1, a flow chart of the process of recovery of cobalt sulphate is depicted, the present invention provides a process for recovery of cobalt sulphate salt from waste lithium ion batteries (LiBs) comprising the steps of:
a) crushing the waste lithium ion batteries into pieces which is processed with chemicals including but not limited to sulphuric acid, hydrogen peroxide and demineralised water in reactor at 90°C for four hours in a reactor unit to provide a slurry of reaction mixture;
b) filtering the slurry of reaction mixture obtained in the step a) to obtain a filtrate and subjecting said filtrate for further processing;
c) feeding the filtrate obtained in the step b) to reactor wherein pH of the solution is adjusted ranging between 3 to 4 using sodium hydroxide
w/v;
d) filtering the pH adjusted solution obtained in the step c) to receive a
cake of residue;
e) feeding the cake obtained in the step d) to reactor for further processing with potassium permanganate to form a solution;

f) filtering the solution obtained in the step e) to remove a cake and to obtain a filtrate;
g) feeding the filtrate obtained in the step f) again into the reactor and adjusting pH of a solution ranging between 5 to 6;
h) feeding the solution obtained in the step g) further for filtration to obtain a filtrate;
i) processing of the filtrate obtained in the step h) by increasing pH of a solution ranging between 11 to 11.5;
C0SO4 + NaOH ► Co(OH)2 + Na2S04
j) filtering the solution obtained in the step i) and distributing a filtrate in to two streams for further salt conversion and to obtain a cake;
k) processing the cake obtained in the step j) in reactor for changing pH ranging between 3 to 4 of a solution using sulphuric acid;
Co(OH)2 + H2S04 ► C0SO4 + H20
1) filtering the solution obtained in the step k) for further processing of a filtrate;
m) elevating pH of the filtrate obtained in the step 1) ranging between 5 to 6 using ammonia for further chemical processing;
n) executing a layer separation in a separating funnel through a (bis/2, 4, 4-trimethylpentyl/phosphinic acid) to obtain a top and a bottom layer;
o) reducing volume of the bottom layer obtained in the step n) in evaporator;
p) reducing the volume further for formation of crystals which settle at the bottom of a surface; and

q) processing of the top layer obtained in the step n) by feeding to crystallizer to obtain cobalt sulphate with the recovery of around 3.0 kg - 6.0 kg of cobalt sulphate from 8 kg powder of lithium ion battery.
EXAMPLE 1 EXPERIMENTAL ANALYSIS
The present invention provides a process for recovery of cobalt sulphate salt from waste lithium ion batteries (LiBs) from 8 kg powder of lithium ion battery comprising the steps of:
a) crushing the waste lithium ion batteries, (in which 8.5% of cobalt sulphate is present) into pieces which is processed with chemicals including but not limited to sulphuric acid ranging between 3 to 4 litres, hydrogen peroxide ranging between 5.5 to 6.5 litres and demineralised water ranging between 60 to 65 litres in reactor at 90°C for four hours in a reactor unit to provide a slurry of reaction mixture;
b) filtering the slurry of reaction mixture obtained in the step a) to obtain a filtrate and subjecting said filtrate for further processing;
c) feeding the filtrate obtained in the step b) to reactor wherein pH of the solution is adjusted ranging between 3 to 4 using sodium hydroxide w/v ranging between 10 to 20 ml/100 ml of filtered solution;
d) filtering the pH adjusted solution obtained in the step c) to receive a cake;
e) feeding the cake obtained in the step d) to reactor for further processing with potassium permanganate ranging between 250 to 300 gm to form a solution;

f) filtering the solution obtained in the step e) to remove a cake and to obtain a filtrate;
g) feeding the filtrate obtained in the step f) again into the reactor and adjusting pH of a solution ranging between 5 to 6;
h) feeding the solution obtained in the step g) further for filtration to obtain a filtrate;
i) processing of the filtrate obtained in the step h) by increasing pH of a solution ranging between 11 to 11.5;
C0SO4 + NaOH ► Co(OH)2 + Na2S04
j) filtering the solution obtained in the step i) and distributing a filtrate in to two streams for further salt conversion and to obtain a cake;
k) processing the cake obtained in the step j) in reactor for changing pH ranging between 3 to 4 of a solution using sulphuric acid;
Co(OH)2 + H2S04 ► C0SO4 + H20
1) filtering the solution obtained in the step k) for further processing of a filtrate;
m) elevating pH of the filtrate obtained in the step 1) ranging between 5 to 6 using ammonia for further chemical processing;
n) executing a layer separation in a separating funnel through a (bis 2, 4, 4-trimethylpentyl phosphinic acid) to obtain a top and a bottom layer;
o) reducing volume of the bottom layer obtained in the step n) in evaporator;
p) reducing the volume further for formation of crystals which settle at the bottom of a surface; and

q) processing of the top layer obtained in the step n) by feeding to crystallizer to obtain cobalt sulphate with the recovery of around 3.3 kg - 3.6 kg (36% to 40%) of cobalt sulphate from 8 kg powder of lithium ion battery.
Hence, through the present invention, 36% to 40% of cobalt sulphate is recovered from 8 kg powder of lithium ion battery. Referring to Figure 2, an extracted cobalt sulphate salt of reddish colour obtained from waste lithium ion batteries (LiBs) is shown.
Therefore, the present invention provides a method for recovery of cobalt sulphate salt and recycling of waste lithium ion batteries for its reuse in several industrial processes. For the extraction of cobalt sulphate salt from LiBs a reactor, filtration techniques, potential hydrogen balances, evaporation techniques, and crystallizers are optimised during a hydro metallurgical process to provide a method which is convenient, easy to process and with lucid steps to follow with proper safety.
Many modifications and other embodiments of the invention set forth herein will readily occur to one skilled in the art to which the invention pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the invention is not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.

CLAIMS
We claim:

1. A process for recovery and recycling of cobalt sulphate from waste lithium- ion batteries comprising steps of:
a) crushing the waste lithium ion batteries into pieces and processing said pieces with chemicals in a reactor unit at predefined temperature and time to provide a slurry of reaction mixture;
b) filtering said slurry of reaction mixture obtained in said step a) to procure a filtrate;
c) feeding said filtrate obtained in said step b) to reactor wherein said solution is adjusted to a desired pH through sodium hydroxide w/v;
d) filtering said pH adjusted solution obtained in said step c) to procure a cake of residue;
e) feeding said cake obtained in said step d) to reactor for processing with potassium permanganate to form a solution;
f) filtering said solution obtained in said step e) to remove a cake and to procure a filtrate;
g) feeding said filtrate obtained in said step f) again into a reactor and adjusting said solution to a desired pH;
h) feeding said solution obtained in said step g) for filtration to procure a filtrate;
i) processing said filtrate obtained in said step h) by increasing said solution to a desired pH;

j) filtering said solution obtained in said step i) and distributing said filtrate into two streams for salt conversion and to procure a cake;
k) processing said cake obtained in said step j) in reactor for changing pH of a solution to a desired level using sulphuric acid;
1) filtering the solution obtained in said step k) for processing of said filtrate;
m) elevating pH of said filtrate obtained in said step 1) to desired level using ammonia for chemical processing;
n) executing a layer separation in a separating funnel through an acid to obtain a top and a bottom layer;
o) reducing volume of said bottom layer obtained in the step n) in evaporator;
p) reducing the volume further for formation of crystals which settle at said bottom of a surface; and
q) processing of said top layer obtained in said step n) by feeding to crystallizer to obtain cobalt sulphate;
wherein:
said recovery of cobalt sulphate is around 3.0 kg to 6.0 kg of cobalt sulphate from 8 kg powder of lithium ion battery having purity of 98%.
2. The process for recovery and recycling of cobalt sulphate from waste lithium ion batteries as claimed in claim 1, wherein said chemicals including but not limited to sulphuric acid ranging between 3 to 4 litres, hydrogen peroxide ranging between 5.5 to 6.5 litres and demineralised water ranging between 60 to 65 litres at 90°C for four hours in a reactor unit.

3. The process for recovery and recycling of cobalt sulphate from waste lithium ion batteries as claimed in claim 1, wherein said pH of said solution is adjusted ranging between 3 to 4 in said step c) through sodium hydroxide w/v ranging between 10 to 20 ml/100 ml of filtered solution.
4. The process for recovery and recycling of cobalt sulphate from waste lithium ion batteries as claimed in claim 1, wherein said pH of said solution is adjusted ranging between 5 to 6 in the said step g).
5. The process for recovery and recycling of cobalt sulphate from waste lithium ion batteries as claimed in claim 1, wherein said pH of said solution is adjusted to 11 to 11.5 in said step i).
6. The process for recovery and recycling of cobalt sulphate from waste lithium ion batteries as claimed in claim 1, wherein said pH of said solution is adjusted ranging between 3 to 4 in step k) through sulphuric acid.
7. The process for recovery and recycling of cobalt sulphate from waste lithium ion batteries as claimed in claim 1, wherein said pH of said solution is adjusted ranging between 5 to 6 in step m) through ammonia.
8. The process for recovery and recycling of cobalt sulphate from waste lithium ion batteries as claimed in claim 1, wherein said reactor is a batch reactor with temperature ranging between 85 to 95°C and pressure ranging between 1 to 2 bar.
9. The process for recovery and recycling of cobalt sulphate from waste lithium ion batteries as claimed in claim 1, wherein said potassium permanganate is ranging between 250 to 300 gm.
10. The process for recovery and recycling of cobalt sulphate from waste lithium ion batteries as claimed in claim 1, wherein said layer separation

in a separating funnel through a bis 2, 4, 4-trimethylpentyl phosphinic acid to obtain a top and a bottom layer.