Method for extracting lithium salt by activating and pressure-leaching spodumene with slaked lime

Abstract

The invention discloses a method for extracting lithium salt by activating and pressure-leaching spodumene with slaked lime. The method comprises the following steps: (1) crystal form conversion; (2)activation and super-grinding; (3) pressure leaching; and (4) separation and purification. According to the method, the high-efficiency leaching of lithium in the spodumene is realized by adopting a slaked lime activation and pressure leaching process. Compared with a conventional process, the lithium salt leaching rate is high, the lithium salt leaching rate is 92% or more than 92%, a lithium salt product with the purity being more than 99.50% can be obtained, the Li2O content in leaching residue is less than or equal to 0.12%, the Si content in a leaching solution is less than 7mg / L, the calcium content is less than 20mg / L, the magnesium content is less than 4mg / L, the sodium content is less than 500mg / L, the potassium content is less than 500mg / L, and the iron content is less than 0.01mg / L. In addition, raw materials used in the invention are low in price and low in cost, the method has the advantages of small slag quantity production and good slag quality, the leaching residue can be recycled, and emission of waste water, waste gas and waste residue is avoided in the process.

Description

technical field

[0001] The invention relates to the technical field of production of lithium salt extracted from spodumene in chemical metallurgy, in particular to a method for extracting lithium salt by using slaked lime to activate press-leached spodumene. Background technique

[0002] Lithium has a series of excellent characteristics such as light weight, soft texture, large specific heat, and high negative potential. It is widely used in batteries, ceramics, glass, lubricants, refrigerants, nuclear industry, and optoelectronics. It is called "energy metal". " and "an important element that drives the world forward" are regarded as important strategic resources of spodumene by many countries. Spodumene (LiAlSi 2 o 6 ) is the main raw material for extracting lithium salt and preparing lithium metal, in which Li 2 The O content is 1-2%, and after enrichment by ore dressing, Li 2 O content can reach 5% to 7%. At present, in the production of spodumene in the production ...

Examples

Embodiment 1

[0024] This embodiment includes the following steps:

[0025] (1) Crystal transformation: The natural spodumene concentrate is roasted at 1050°C for 30 minutes to convert the α-spodumene in the spodumene into β-spodumene, and the Li in the obtained β-spodumene 2 O content is 5%;

[0026] (2) Activation ultra-grinding: mix water and first-grade quicklime according to the liquid-solid ratio of 5:1, stir, and after the reaction is complete, filter out the unreacted residue to obtain active slaked lime slurry, and step (1 ) The β-spodumene obtained by roasting conversion is mixed with slaked lime slurry, activated by ultra-grinding, and the part with a particle size of less than 8 μm accounts for 80%;

[0027] (3) Pressure leaching: put the ultra-grinded slurry in an autoclave, at a leaching temperature of 160°C, a pressure of 0.6MPa, a stirring speed of 500r / min, and leaching for 40min to obtain a lithium salt leaching solution;

[0028] (4) Separation and purification: Evapora...

Embodiment 2

[0031] This embodiment includes the following steps:

[0032] (1) Crystal form conversion: The natural spodumene concentrate was roasted at 1020°C for 40 minutes to convert the α-spodumene in the spodumene into β-spodumene, and the Li in the obtained β-spodumene 2 O content is 5%;

[0033] (2) Ultra-grinding activation: mix water and first-grade lime according to the liquid-solid ratio of 8:1, stir, and after the reaction is complete, filter out the unreacted residue to obtain active slaked lime slurry, and step (1 ) The β-spodumene obtained by roasting conversion is mixed with slaked lime slurry, and activated by ultra-grinding, so that the part with a particle size of less than 10 μm accounts for 80%;

[0034] (3) Pressure leaching: put the ultra-grinded slurry in an autoclave, at a leaching temperature of 180°C, a pressure of 1.0MPa, a stirring speed of 800r / min, and leaching for 80min to obtain a lithium salt immersion solution; among them, Lithium salt leaching rate is ...

Embodiment 3

[0038] This embodiment includes the following steps:

[0039] (1) Crystal form conversion: The natural spodumene concentrate was roasted at 1080°C for 50 minutes to convert the α-spodumene in the spodumene into β-spodumene, and the Li in the obtained β-spodumene 2 O content is 5%;

[0040](2) Activation ultragrinding: mix water and primary lime according to the liquid-solid ratio of 8:1, stir, and after the reaction is complete, filter out the unreacted residue to obtain active slaked lime slurry, and step (1 ) The β-spodumene obtained by roasting conversion is mixed with slaked lime slurry, and activated by ultra-grinding, so that the part with a particle size of less than 7 μm accounts for 80%;

[0041] (3) Pressure leaching: put the ultra-grinded slurry in an autoclave, at a leaching temperature of 200°C, a pressure of 1.55 MPa, a stirring speed of 800r / min, and leaching for 120min to obtain a lithium salt leaching solution;

[0042] (4) Separation and purification: The l...

technical field

[0001] The invention relates to the technical field of production of lithium salt extracted from spodumene in chemical metallurgy, in particular to a method for extracting lithium salt by using slaked lime to activate press-leached spodumene. Background technique

[0002] Lithium has a series of excellent characteristics such as light weight, soft texture, large specific heat, and high negative potential. It is widely used in batteries, ceramics, glass, lubricants, refrigerants, nuclear industry, and optoelectronics. It is called "energy metal". " and "an important element that drives the world forward" are regarded as important strategic resources of spodumene by many countries. Spodumene (LiAlSi 2 o 6 ) is the main raw material for extracting lithium salt and preparing lithium metal, in which Li 2 The O content is 1-2%, and after enrichment by ore dressing, Li 2 O content can reach 5% to 7%. At present, in the production of spodumene in the production ...

Examples

Embodiment 1

[0024] This embodiment includes the following steps:

[0025] (1) Crystal transformation: The natural spodumene concentrate is roasted at 1050°C for 30 minutes to convert the α-spodumene in the spodumene into β-spodumene, and the Li in the obtained β-spodumene 2 O content is 5%;

[0026] (2) Activation ultra-grinding: mix water and first-grade quicklime according to the liquid-solid ratio of 5:1, stir, and after the reaction is complete, filter out the unreacted residue to obtain active slaked lime slurry, and step (1 ) The β-spodumene obtained by roasting conversion is mixed with slaked lime slurry, activated by ultra-grinding, and the part with a particle size of less than 8 μm accounts for 80%;

[0027] (3) Pressure leaching: put the ultra-grinded slurry in an autoclave, at a leaching temperature of 160°C, a pressure of 0.6MPa, a stirring speed of 500r / min, and leaching for 40min to obtain a lithium salt leaching solution;

[0028] (4) Separation and purification: Evapora...

Embodiment 2

[0031] This embodiment includes the following steps:

[0032] (1) Crystal form conversion: The natural spodumene concentrate was roasted at 1020°C for 40 minutes to convert the α-spodumene in the spodumene into β-spodumene, and the Li in the obtained β-spodumene 2 O content is 5%;

[0033] (2) Ultra-grinding activation: mix water and first-grade lime according to the liquid-solid ratio of 8:1, stir, and after the reaction is complete, filter out the unreacted residue to obtain active slaked lime slurry, and step (1 ) The β-spodumene obtained by roasting conversion is mixed with slaked lime slurry, and activated by ultra-grinding, so that the part with a particle size of less than 10 μm accounts for 80%;

[0034] (3) Pressure leaching: put the ultra-grinded slurry in an autoclave, at a leaching temperature of 180°C, a pressure of 1.0MPa, a stirring speed of 800r / min, and leaching for 80min to obtain a lithium salt immersion solution; among them, Lithium salt leaching rate is ...

Embodiment 3

[0038] This embodiment includes the following steps:

[0039] (1) Crystal form conversion: The natural spodumene concentrate was roasted at 1080°C for 50 minutes to convert the α-spodumene in the spodumene into β-spodumene, and the Li in the obtained β-spodumene 2 O content is 5%;

[0040](2) Activation ultragrinding: mix water and primary lime according to the liquid-solid ratio of 8:1, stir, and after the reaction is complete, filter out the unreacted residue to obtain active slaked lime slurry, and step (1 ) The β-spodumene obtained by roasting conversion is mixed with slaked lime slurry, and activated by ultra-grinding, so that the part with a particle size of less than 7 μm accounts for 80%;

[0041] (3) Pressure leaching: put the ultra-grinded slurry in an autoclave, at a leaching temperature of 200°C, a pressure of 1.55 MPa, a stirring speed of 800r / min, and leaching for 120min to obtain a lithium salt leaching solution;

[0042] (4) Separation and purification: The l...