US006555078B1

(12) United States Patent (10) Patent N0.: US 6,555,078 B1

Mehta (45) Date of Patent: Apr. 29, 2003

(54) METHOD OF PREPARING LITHIUM SALTS 4,477,367 A 10/1984 Burba, 111

4,540,509 A 9/1985 Burba, III
(75) Inventor: Vijay Chandrakant Mehta, Gastonia, 4,723,962 A 2/1988 Mehta
NC (Us) 4,859,343 A 8/1989 FrianeZa-Kullberg et al.
4,980,136 A 12/1990 Brown et al.
- _ - ~ - 5,378,445 A 1/1995 Salmon et al.
(73) Assignee. FIlJVéC Corporation, Philadelphia, PA 5,389,349 A 2/1995 Bauman et a1‘
( ) 5,599,516 A 2/1997 Bauman et al.
(*) Notice: Subject to any disclaimer, the term of this FOREIGN PATENT DOCUMENTS
patent is extended or adjusted under 35 DE 1 183 484 12/1964
U.S.C. 154(b) by 661 days. SE 101 323 4/1941

(21) Appl. N0.: 08/931,635 OTHER PUBLICATIONS

(22) Filed; Sep, 16, 1997 LeWis,HaWleys Condensed Chem. Dict., 12th ed.,pp. 706,
707,709,950,951,955,1051,1052,1063, 1993*
Related US. Application Data Stenger, Solubilities of . . . in Methanol, J. Chem. Eng. Data,
(60) Provisional application No. 60/026,717, ?led on Sep. 26, VOl. 41, NO. 5, pp. 1111—1113, Sep. 1996*
1996, and Provisiona1 application No- 60/026,738, ?led 0n Perrin, Puri?cation of Laboratory Chemicals, Second Edi
SeP- 26’ 1996- tion, pp. 1, and 46—47, 1980*
(51) Int. Cl.7 .............................................. .. C01D 15/00 R- T- Sanderson, Principles of Chemistry, pp. 389—398, Mar.
(52) US. Cl. .................. .. 423/179.5; 423/277; 423/332; 1964* _ _ _ _
423/395; 423/400; 423/463; 423/464; 423/518; Morton, Laboratory Technique in Organic Chemistry, pp.
423/5192; 423/515; 423/551; 423/566.2; 195—197, 1938*
423/605; 423/606; 423/641; 423/642; 423/643; PCT International Search Report, PCT/US 97/16811, com
423/646; 562/477; 562/493; 562/578; 562/582; pleted Jan 13, 1998 by W- Van der P991
562/584; 562/588; 562/607; 562/609 Structure of Operation of Dow’s New Lithium—Selective
(58) Field Of Search ............................... .. 423/395 277 low/Exchange Resin, W- Bauman et all» John Wiley & S°I1S>
423/332, 464, 463, 500, 606, 642, 643, 1985,1111 29—34~ _ _ _ _
646 605 400 515 518 5192 551 5662 Gmellns Handbuch Der Anorganlschen Chemie, Llthlum
62H 1’79_5.’562/;(77 293 57,8 58,2 584’ Ergr'z'nzungsbana', 1960, Verlag Chemie, Weinheim, DE, p.
588, 589, 607, 609 262
_ * cited by examiner
(56) References Cited
Primary Examiner—Shailendra Kumar
U'S' PATENT DOCUMENTS (74) Attorney, Agent, or Firm—Myers Bigel Sibley &
3,278,260 A 10/1966 Hermann SaJOVGC, P-A
3,306,700 A 2/1967 Neipert et al.
3,523,751 A * 8/1970 Burkert et al. ............... .. 23/63 (57) ABSTRACT
2 g iherubnln et a1‘ The present invention provides an inexpensive process for
4’116’858 A 41978 If: 2: :1‘ the preparation of lithium salts of formula LiX having a
4’159’311 A 6/1979 Lee et al' desired or required level of purity using lithium chloride and
4,216,192 A * 8/1980 Rao et all _________________ __ 423/366 lithium sulfate. In the process of the invention, a lithium salt
4:221j767 A 9/1980 Lee et a1_ selected from lithium chloride, lithium sulfate, and combi
4,274,834 A 6/1981 Brown et a1, nations thereof is reacted With NaX or KX in a aqueous,
4,291,001 A 9/1981 Repsher et al. semiaqueous, or organic solution and the precipitated salts
4,347,327 A 8/1982 Lee et al- are removed to obtain the LiX solution of desired purity.
43487295 A 9/1982 Burba: HI Preferably, a semiaqueous solution containing Water and an
4348296 A 9/1982 Bauman et a1‘ organic solvent is used at some point in the reaction. The
2 22:11:12? a ' process of the invention eliminates the use of highly acidic
4’381’349 A 4/1983 Lee et al' materials and thus reduces the cost of raW materials and the
474307311 A 2/1984 Lee et a1: need for specialized equipment.
4,461,714 A 7/1984 Burba, 111
4,472,362 A 9/1984 Burba, III 25 Claims, N0 Drawings
 US 6,555,078 B1
1 2
METHOD OF PREPARING LITHIUM SALTS reacting a lithium salt selected from lithium chloride,
lithium sulfate, and combinations thereof With NaX or KX
CROSS-REFERENCE TO RELATED in an aqueous, semiaqueous and/or organic solution and
APPLICATIONS removing the precipitated solids from the semiaqueous
solution to obtain a LiX solution of desired purity. Any
This application is related to commonly owned provi
combinations of solvents can be used in the invention but
sional application Ser. No. 60/026,717, ?led Sep. 26, 1996, preferably the lithium salt and NaX or KX salt are reacted
and provisional application Ser. No. 60/026,738, ?led Sep.
in a semiaqueous solution containing Water and an organic
26, 1996, and claims the bene?t of the earlier ?ling dates of
these applications under 35 U.S.C. §119(e). solvent. Nevertheless, the semiaqueous reacting step can be
10 preceded by an aqueous reacting step or can be replaced by
FIELD OF THE INVENTION successive aqueous and organic reacting steps. Typically, the
organic solvent in the semiaqueous and organic solutions is
The present invention is directed to a process for prepar selected from aliphatic ketones, aliphatic alcohols, and mix
ing lithium salts, and speci?cally, to an inexpensive process tures thereof. The process of the invention has been found
for preparing lithium salts from loW cost lithium chloride 15 especially useful for producing lithium salts of formula LiX
and lithium sulfate. Wherein the solubility of LiX in the solution used is greater
than the solubility of the sodium or potassium salts produced
BACKGROUND OF THE INVENTION
as by-products in the reacting step.
Lithium salts have found utility in various applications. Use of sulfate salts as part of the starting materials or feed
For example, lithium nitrate is knoWn for use in ceramics, 20 can require a cooling step to precipitate the resultant sodium
pyrotechnics, salt baths, heat exchange media, refrigeration and/or potassium sulfate salts, such as Na2SO4.10H2O,
systems, rocket propellants and specialiZed concrete appli K2SO4, KLiSO4.H2O, NaLiSO4.H2O, and the like. The use
cations. Another useful lithium salt, lithium bromide, is of chloride salts as starting materials or feed can require
knoWn for use in pharmaceuticals, air conditioning systems, higher temperatures to reject the resultant sodium salt NaCl
loW temperature heat exchange media, drying agent, refrig 25 and loWer temperatures for the resultant potassium salt KCl
eration systems, batteries, medicine and as a humectant. from aqueous metathesis salting out. To purify LiNO3 and/or
The conventional method of producing many lithium salts LiBr salt solutions, a solvent step metathesis step can be
is to combine either lithium carbonate or lithium hydroxide required for precipitation removal of sodium and/or potas
With acids containing the desired anion for the lithium salt. sium as chloride and/or sulfate salts.
For example, the conventional method of producing lithium 30
In a speci?c embodiment of the invention, the process for
nitrate is to react lithium carbonate and/or lithium hydroxide preparing a lithium salt of formula LiX having a desired or
With nitric acid. Nevertheless, this process requires high required purity comprises dissolving lithium chloride,
purity raW materials and very expensive plant equipment lithium sulfate, or a mixture thereof and a NaX salt, KX salt,
and metal of construction for the handling of the highly or mixture thereof, in an aqueous solution and ?ltering the
alkaline lithium salts and concentrated nitric acid. 35
solution to remove the precipitated sodium and potassium
Similarly, the conventional method of producing lithium salts. An aliphatic ketone, an aliphatic alcohol, or a mixture
bromide is to react hydrobromic acid With lithium hydroxide thereof, is then added to the solution to form a semiaqueous
or lithium carbonate. The saturated solution on cooling solution, and the precipitated sodium and potassium salts are
precipitates lithium bromide monohydrate, Which can be again ?ltered from the solution. In addition, a monovalent
40
dried to the anhydrous salt. Nevertheless, hydrobromic acid cation sulfate salt can be added to the semiaqueous solution
is a very irritating colorless gas that fumes strongly in moist to cause the salting out or precipitation of undesired sodium
air. Furthermore, hydrobromic acid is classi?ed under DOT and potassium salts from the solution thereby purifying the
regulations, as highly corrosive, and highly irritative to eyes, solution. The organic solvent is then removed and the
skin and respiratory passages. Therefore, the production of resulting LiX solution of desired purity is recovered. The
45
lithium bromide using hydrobromic acid can be quite dan LiX solution can then be dried Where solid LiX salt is
gerous. desired as the end product or stored and sold in solution.
As described above, the use of highly acidic materials in These and other features and advantages of the present
the formation of lithium salts is undesirable as the materials invention Will become more readily apparent to those skilled
are generally haZardous and require special equipment. in the art upon consideration of the folloWing detailed
Furthermore, the above processes generally do not produce description Which describes both the preferred and alterna
high yields of the lithium salts being produced and therefore tive embodiments of the present invention.
cannot be used Where high purity lithium salts are desired.
Therefore, there is a need to provide an inexpensive method DETAILED DESCRIPTION OF THE
of increasing the purity of the lithium salts Without using INVENTION
55
highly acidic materials. The process of the invention comprises preparing a
SUMMARY OF THE INVENTION lithium salt of formula LiX having a desired or required
purity by reacting a lithium salt selected from lithium
The present invention provides an inexpensive process for chloride, lithium sulfate, and combinations thereof With
the preparation of lithium salts using lithium chloride and 60 NaX or KX in an aqueous, semiaqueous or organic solution
lithium sulfate. The process of the invention eliminates the and removing the precipitated solids from the solution to
use of highly acidic materials and thus reduces the cost of obtain a LiX solution of desired purity. Any combination of
raW materials and the need for specialiZed equipment. The solvents can be used in accordance With the invention.
process produces lithium salts of desired purity Without Preferably, a semiaqueous solution is used containing Water
compromising safety in the production of these salts. 65 and an organic solvent. The reaction can also be initiated in
The process of the invention comprises preparing a an aqueous solution and then continued in either a semi
lithium salt of formula LiX of desired or required purity by aqueous or an organic solution to provide the LiX salts of the
 US 6,555,078 B1
3 4
invention. As used herein, and as Will be appreciated by the the solution is agitated and can be heated to facilitate the
skilled artisan, the term “salt” unless otherWise speci?cally formation of the semiaqueous or organic solution. It can also
de?ned can refer to a salt provided in solid or liquid form be bene?cial in the case of the semiaqueous solution to
(for example as brine solutions). dilute the solution by adding Water to the solution to bring
The lithium chloride and lithium sulfate salts used in the the amount of dissolved solids in the solution to less than 50
process are inexpensive and readily available in anhydrous Weight percent prior to adding the organic solvent. The
form, hydrated form, or in solution. Typically, the lithium preferred organic solvents for use in the process of the
chloride is obtained in puri?ed form as a liquid as Well as an invention are aliphatic ketones (e.g. primary and secondary
anhydrous salt from geothermal brine deposits such as those C1—C10 ketones), aliphatic alcohols (e.g. primary and sec
in Chile and Argentina by selective adsorption and solar 10
ondary C1—C10 alcohols), and mixtures thereof. Exemplary
evaporation. Lithium sulfate is obtained from spodumene ketones and alcohols include Without limitation acetone,
ore by conventional roasting, acid leach and puri?cation dimethylketone, diethylketone, methanol, ethanol, propanol,
steps, and from brine by conventional routes. The NaX or pentanol, hexanol, and the like, and preferably is acetone,
KX salts are also available in anhydrous form, hydrated methanol and/or ethanol, and more preferably acetone and/
form, or in solution and can be available as mixtures of NaX 15 or methanol.
and KX. Advantageously, the lithium chloride, lithium Preferably, the amount of organic solvent in the semi
sulfate, NaX and KX can be used in liquid and Well as solid aqueous or organic solution is greater than 0 moles and less
form. Thus, Where the transport of the raW materials is not than 10 moles per mole of LiX. More preferably, the amount
a concern, the lithium chloride, lithium sulfate, NaX and KX of organic solvent is betWeen about 0.25 moles and about 3
can be used in liquid form and thus do not require drying. As 20 moles per mole of LiX. The amount of Water present in the
a result, the cost of the raW materials used in the process is semiaqueous solution is as described above. Preferably, the
reduced. amount of Water (semiaqueous solution) and organic solvent
The process of the invention is preferably initiated by in the semiaqueous or organic solution is suf?cient to keep
dissolving lithium chloride, lithium sulfate, or a mixture the LiX in solution beloW or close to saturation at the
thereof and a NaX salt, KX salt, or a mixture thereof, in an 25 operating temperature. The addition of the organic solvent
aqueous solution. The dissolution of these reactants occurs and ?ltration of the precipitated solids is typically conducted
by dissolving lithium chloride or lithium sulfate in a NaX or at betWeen 0 and 60° C., preferably, betWeen about 0° C. and
KX solution, dissolving NaX or KX in a lithium chloride or 30° C., and under atmospheric or subatmospheric pressure
lithium sulfate solution, or mixing an aqueous solution of (0 to 25 mm Hg). In addition, the pH of the semiaqueous
lithium chloride or lithium sulfate With an aqueous solution 30 solution is typically betWeen about 5 and 10, preferably
of NaX or KX. In addition, the solution can be heated and/or betWeen about 7 and 9.
agitated to facilitate the dissolution of the salts in the Once the organic solvent has been added to the solution,
solution. Preferably, the dissolving step is conducted at additional sodium and potassium salts precipitate out of the
betWeen 0 and 120° C. and under atmospheric or subatmo semiaqueous solution. In addition to the organic solvent, a
spheric pressure (5 to 25 mm Hg). 35 sulfate salt having a monovalent cation, e.g., an alkali metal
As the salts are combined in solution, the lithium chloride sulfate, such as but not limited to Na2SO4, Na2SO4.10H2O,
and lithium sulfate reacts With the NaX and KX salts in a LiSO4, LiSO4.H2O, KLiSO4.1/2H2O, K2504, and
substitution or metathesis reaction to form LiX as the NaLiSO4.H2O, and the like, can be added to the solution
desired end product and NaCl, Na2SO4, KCl, K2SO4 and the With the organic solvent or prior to drying the aqueous
like as by-products. The LiX is preferably more soluble in 40 solution to facilitate precipitation of the sodium and potas
the aqueous solution than the sodium and potassium salts, sium salts. Preferably, the added sulfate salt is sodium
ie the salt by-products and any excess NaX or KX present sulfate or potassium sulfate to correspond to the salt origi
in the solution, thereby causing the sodium and potassium nally added in the process to provide the X anion for the LiX
salts to precipitate out of solution before the LiX salt. The salt. The precipitated salts are removed from the semiaque
solution is often concentrated such as by evaporating off the 45 ous solution such as by ?ltering. In addition, Where elevated
Water or other means to thereby increase precipitation of the temperatures are used for the semiaqueous solution, the
sodium and potassium salts. Preferably, the solution is solution temperature can be decreased to cause greater
concentrated such that the solution contains from greater precipitation of the sodium and potassium salts.
than 0 to about 4 moles of Water per mole of LiX. More Once the precipitated solids have been substantially
preferably, the aqueous solution contains betWeen about 1 removed from the lithium solution, the organic solvent is
mole and 3 moles of Water per mole of LiX. The amount of removed next from the solution. The organic solvent can be
Water in solution is preferably sufficient to keep the LiX in recycled into the process. The recovery of the organic
solution beloW or close to saturation at the operating tem solvent from the solution is preferably facilitated by con
perature. Typically, the pH of the aqueous solution is centrating the solution such as by heating the solution to
betWeen about 5 and 10, preferably betWeen about 6 and 8. 55 evaporate (distillation) the organic solvent. The resulting
In addition, Where the solution has been heated, the solution LiX solution or salt can have a purity of 95% or greater,
can be cooled to help precipitate more sodium and potas preferably 99% or greater, and is recovered in the process.
sium salts from the solution. Once the sodium and potassium When a semiaqueous solution is used, the LiX solution can
salts precipitate, these salts can be removed from the aque then be concentrated to increase the amount of solids in the
ous solution by continuously ?ltering the solution or other 60 solution or dried to form a LiX salt of desired purity.
suitable means. Although the process of the invention is described as a
Once the partially precipitated sodium and potassium salts tWo-step process in Which precipitation occurs ?rst in an
have been removed from the aqueous solution for further aqueous solution and then in a semiaqueous or organic
puri?cation, an organic solvent is added to the aqueous solution, the process can be conducted as a one-step process
solution to form a semiaqueous solution. Alternatively, the 65 Wherein only the semiaqueous solution is used under the
Water can be removed completely in the solution and the semiaqueous conditions described above. In particular, the
organic solvent added to form an organic solution. Typically, one-step process is preferred Wherein LiX is less soluble in
 US 6,555,078 B1
5 6
Water than the sodium and potassium salts but more soluble The present invention Will noW be further illustrated by
in the semiaqueous solution than the sodium and potassium the folloWing non-limiting examples. All percentages unless
salts. In addition, the process of the invention can be otherWise indicated are on a per Weight basis.
conducted in a batch, semi-batch or continuous process to
produce the LiX salts. Preferably, for the large-scale pro EXAMPLE 1
duction of lithium salts, a continuous or semi-batch process
is used in accordance With the invention. Five hundred grams of Water in a 1000 ml beaker Was
The present invention can be used to form various LiX heated to 60° C. and 210 g NaNO3 Was added With sloW
salts. Preferably, as Will be readily understood to one skilled agitation to obtain a clear solution. Next, 100 g of anhydrous
in the art, the process of the invention is used to produce LiX high purity LiCl Was added sloWly to the NaNO3 solution
10
salts having a greater solubility in the solutions used than the With agitation to again obtain a clear solution. Next, the
sodium or potassium salts present in these solutions. In brine Was alloWed to concentrate by removing Water and salt
particular, the process of the invention can be used to formation started after removal of about 150—200 g Water.
produce a lithium salt of formula LiX Wherein X is an anion The evaporation of Water and the salt removal by ?ltration
selected from nitrate, bromide, chloride, iodide, borate of the Warm slurry Was continued until the ?nal ?ltrate
15 reached 350 g. The salt cake Was Washed With ?ne Water
(tetraborate), acetate, pentaborate, acetylsalicylate, amide,
benZoate, chlorate, perchlorate, chloroplatinate, chromate, spray and the Wash Was recycled With the mother liquor.
citrate, dichromate, ?uosilicate, ?uosulfonate, formate, Next, the ?ltrate Was alloWed to cool to 20° C. and ?ltered
hydroxide, hypochlorite, iodate, lactate, permanganate, to remove solids. The ?ltrate (about 295 g) and the total
methoxide, molybdate, nitrite, niobate, oxalate, oxide, solids (about 142 g) Was recovered and sampled for analysis.
20
salicylate, sulfate, sul?de, sul?te, tartrate, thiocyanate, The analysis of the ?ltrate shoWed 5.58% Li", 1.66% Na",
dithionate, tungstate, and vanadate. Preferably, the process 54.39% NO; and 0.22% Cl“. Next, 200 ml of the ?ltrate
of the invention is used to make lithium nitrate or lithium Was diluted With Water to about 240 ml to bring the total
bromide. dissolved solids to beloW 50%. One hundred milliliters of
The process of the invention alloWs LiX to be produced dimethylketone Was added to the ?ltrate With sloW agitation
25
from NaX and KX salts Which are generally more readily and at room temperature. The mixture Was alloWed to agitate
available and are therefore less expensive than the related for 60 minutes and then ?ltered to remove solids. The ?ltrate
LiX salts. For example, sodium nitrate (also called Chilean Was concentrated to recover dimethylketone at loW pressure
nitrate or Chile saltpeter) is abundantly available in South and a temperature betWeen 25 and 60° C. The ?nal solution
American salt deserts and potassium nitrate is made from once free from organic solvent Was analyZed and contained
30
sodium nitrate in Chile. Sodium bromide is recovered as a 4.64% Li", 0.105% Na”, 41.369% N03“, and less than 0.2%
by-product from solutions obtained during bromination, CI‘.
bromo-oxidation and hydrolysis of organic bromide com EXAMPLE 2
pounds. Furthermore, large amounts of potassium bromide
are made from the neutraliZation of HBr With KOH or 35 Four hundred tWenty-?ve (425) grams of Water in a 1000
K2CO3. Any excess NaX and KX salts Which are recovered ml beaker Was heated to 65° C. and 450 g NaNO3 Was added
in the process can be separated and recycled into the process. to the beaker and dissolved completely. Next, 215 g anhy
Another advantage of the process of the invention is that drous LiCl Was dissolved in 375 g of Water in a separate
high purity raW materials are not required to produce the LiX beaker. The LiCl solution Was added sloWly to the NaNO3
solutions or salts having the desired or required purity. 40 solution With agitation. The resulting solution turned into a
Speci?cally, because undesired salts generally precipitate slurry indicating precipitation of the NaCl salt. The solution
out of the solution during the process of the invention, Was concentrated by removing about 200 g of Water. The
impurities can be present in the raW materials. Thus, more 1265 g slurry Was ?ltered hot and the ?lter cake Was Washed
expensive high purity raW materials are not necessary in With 30 g of a Water spray. The resulting Wet cake Was dried
order to produce LiX having a desired purity according to 45 and Weighed 123 g. The ?ltrate Was concentrated further to
the invention. 980 g by removing 195 g of Water. The resulting slurry Was
A further advantage of the process is that the salt ?ltered and the ?lter cake Was Washed With 20 g of Water.
by-products, i.e., the sodium and potassium salts, are useful The ?lter cake Was dried and Weighed 32 g. Next, the 968
chemicals and thus are not discarded as Waste. For example, g ?ltrate and Wash Were concentrated in a similar fashion in
potassium chloride is a raW material for manufacturing 50 tWo steps at 90° C. to obtain 620 g ?ltrate and 90 g Washed
potassium nitrate from Chile saltpeter (NaNO3) and potas dry salts. Atotal of 45 g of Water Was used to Wash the ?lter
sium sulfate is a very valuable potash fertiliZer. In addition, cake in these tWo steps. The ?ltrate (620 g) and collected
NaCl (table salt) and Na2SO4 (salt cake) have uses Which are salts Were analyZed using conventional techniques and con
Well knoWn in the art. tained the folloWing:
The present invention provides an inexpensive process for 55
the preparation of lithium salts using lithium chloride and
lithium sulfate. The process of the invention eliminates the Hot Filtrate Salts
use of highly acidic materials and thus reduces the cost of
raW materials and the need for specialiZed equipment. Li’“ 5.60% 0.20%
Na’“ 4.65% 37.90%
Therefore, the process produces lithium salts having a 60
N03’ 52.22% 1.79%
desired or required level of purity Without compromising CI’ 5.50% 58.42%
safety in the production of these salts. Additionally, lithium
chloride and lithium sulfate can be used in both solid and
solution form in the process and thus do not have to be dried
EXAMPLE 3
out prior to use. Advantageously, the by-products of the 65
process of the invention have other useful applications and TWenty-three grams of Glauber salt (Na2SO4:10H2O) Was
thus the process produces little Waste. added to 310 g of the hot ?ltrate from Example 2 and the
 US 6,555,078 B1
7 8
solution Was allowed to concentrate to dryness using obtain a ?nal product solution of LiBr With very loW sodium
rotovap. The dried salts Were cooled to 50° C. Next, 250 ml and chloride content.
of absolute methyl alcohol Was added to the dried salts With It is understood that upon reading the above description of
agitation. The slurry Was agitated betWeen at room tempera the present invention, one skilled in the art could make
ture and 50° C. to dissolve LiNO3. After three hours of changes and variations therefrom. These changes and varia
agitation at any given temperature betWeen 10° C. and 50° tions are included in the spirit and scope of the folloWing
C., the slurry Was ?ltered to remove undissolved salts. The appended claims.
?ltrate and the solids Were dried under vacuum to recover That Which is claimed:
alcohol for recycling into the process and both of the 1. A method for preparing a lithium salt of formula LiX,
resulting solids Were analyZed. The results Were as folloWs: 10
comprising:
reacting lithium salt selected from lithium chloride,
lithium sulfate, and combinations thereof With NaX or
KX in an aqueous solution;
LiNO3 solids from Undissolved adding an organic solvent to the aqueous solution to
alcohol ?ltrate Salts
15
produce a semiaqueous solution; and
Wt. 170 g 55 g removing the precipitated solids from the semiaqueous
Li” 9.900% 0.90% solution to obtain a LiX solution.
Na” 0.380% 30.90% 2. The method of claim 1 Wherein said adding step
N03’ 87.260% 24.60% comprises adding an organic solvent selected from aliphatic
Cl’ 0.068% 30.90% ketones, aliphatic alcohols, and mixtures thereof.
5042* 0.005% 12.30% 20
3. The method of claim 1 further comprising, prior to said
adding step, the step of solution removing the precipitated
solids from the aqueous solution.
EXAMPLE 4 4. The method of claim 1 Wherein X of the NaX or KX
TWenty-three grams of Glauber salt (Na2SO4:10H2O) Was salts in the reacting step is selected such that the solubility
25 of LiX in the aqueous solution is greater than the solubility
added to 310 g of the hot ?ltrate from Example 2 With
agitation. The solution Was cooled to 50° C. and 250 ml of of the sodium or potassium salts produced in the reacting
ethyl alcohol Was added to the solution With agitation. The step and the solubility of LiX in the semiaqueous solution is
solution Was alloWed to cool doWn to 20° C. After three greater than the solubility of the sodium or potassium salts
hours of agitation at 20° C., the slurry Was ?ltered to remove produced in the reacting step.
salts. The alcohol Was recovered from the process for 5. The method of claim 1 Wherein X is an anion selected
recycling into the process and the solution and ?ltered solids from nitrate, bromide, chloride, iodide, acetate, borate
Were analyZed. The results Were as folloWs: (tetraborate), pentaborate, acetylsalicylate, amide, benZoate,
chlorate, perchlorate, chloroplatinate, chromate, citrate,
dichromate, ?uosilicate, ?uosulfonate, formate, hydroxide,
35 hypochlorite, iodate, lactate, permanganate, methoxide,
LiNO3 soln. from Undissolved molybdate, nitrite, niobate, oxalate, oxide, salicylate,
alcohol ?ltrate Salts sulfate, sul?de, sul?te, tartrate, thiocyanate, dithionate,
Wt. 350 g 47 g tungstate, and vanadate.
Li’“ 4.850% 0.77% 6. A method for preparing lithium nitrate or lithium
Na’“ 0.472% 34.05% 40 bromide, comprising:
N03’ 44.145% 15.70% reacting lithium salt selected from lithium chloride,
Cl’ 0.290% 34.15%
SO42’ 0.009% 14.32% lithium sulfate, and combinations thereof With NaNO3,
NaBr, KNO3 or KBr in an aqueous, semiaqueous or
organic solution; and
45
EXAMPLE 5 removing the precipitated solids from the solution to
obtain a LiNO3 or LiBr solution.
Five hundred grams of Water in a 1000 ml beaker Was 7. The method of claim 1 further comprising the step of
heated to 60° C. and 250 g anhydrous NaBr Was added to adding a sulfate salt having a monovalent cation to the
obtain a clear solution. Next 100 g of anhydrous LiCl Was semiaqueous solution.
added sloWly With moderate agitation. The mix Was alloWed 50
8. A method for preparing a lithium salt of formula LiX,
to agitate for one hour at betWeen 60°C. and 80° C. Fine comprising:
White solids Were precipitated from the metathesis reaction.
reacting lithium salt selected from lithium chloride,
Next, the slurry Was concentrated by removing Water under
lithium sulfate, and combinations thereof With NaX or
loW pressure and the slurry Was ?ltered simultaneously to
KX salt in an aqueous solution;
remove solids. The solid Wet cake Was Washed With ?ne 55
Water spray to recover LiBr entrainment. The ?ltrate and the removing the precipitated solids from the aqueous solu
Wash Were recycled to the evaporator. The evaporation and tion;
?ltration With Washing of the ?lter cake Was continued until drying the aqueous solution and recovering the dried salts;
the ?nal ?ltrate Was about 320 g. The ?ltrate Was alloWed to preparing an organic solution comprising the salts from
cool to 20° C. and ?ltered again to remove salts from the 60 said drying step; and
solution. The clear brine ?ltrate (about 250 g) and the total removing the precipitated solids from the organic solu
solids (about 152 g) Were sampled for analysis. The chemi tion.
cal analysis of the brine solids shoWed 5.2% Li", 0.153% 9. A method for preparing a high purity lithium salt of
Na”, 53% Br“, and 0.064% C1“. The ?ltrate from evapora formula LiX comprising:
tion and cooling can then be mixed With diketones, such as dissolving lithium chloride, lithium sulfate, or a mixture
acetone, and/or a loW carbon primary alcohol, such as thereof and a NaX salt, KX salt, or a mixture thereof,
methanol, to precipitate out excess sodium halide salts to in an aqueous solution;
 US 6,555,078 B1
9 10
?ltering the solution to remove the sodium and potassium 16. The method of claim 9 Wherein said step of dissolving
salts; comprising heating thee solution and said method further
adding an organic solvent selected from an aliphatic comprises the step of heating and cooling and ?ltering the
ketone, an aliphatic alcohol and a mixture thereof, to solution to remove additional sodium and potassium salts
form a semiaqueous solution; prior to said step of adding an organic solvent.
?ltering the precipitated sodium and potassium salts from 17. The method of claim 9 further comprising the step of
the semiaqueous solution; diluting the solution to bring the amount of dissolved solids
removing the organic solvent from the solution; and in the solution to less than 50 Weight percent prior to the step
recovering the resulting LiX solution. of adding an organic solvent.
10
10. The method of claim 9 further comprising the step, 18. The method of claim 9 Wherein after said step of
after said dissolving step, of concentrating the salts in the adding the organic solvent, the amount of Water in the
solution thereby increasing precipitation of the sodium and semiaqueous solution is greater than 0 moles and less than
potassium salts. 4 moles per mole of LiX and the amount of organic solvent
11. The method of claim 9 Wherein the step of removing 15
in the solution is greater than 0 moles and less than 10 moles
the organic solvent from the solution comprises concentrat per mole of LiX.
ing the solution to facilitate removal of the organic solvent 19. The method of claim 9 Wherein the amount of Water
from the solution. in solution during said ?rst ?ltering step is suf?cient to keep
12. The method of claim 9 Wherein X is selected such that the LiX in solution beloW or close to saturation at the
the solubility of LiX in the aqueous and semiaqueous 20 operating temperature.
solutions is greater than the solubility of the sodium or 20. The method of claim 9 Wherein the amount of Water
potassium salts produced in the reacting step. and organic solvent in the solution during said second
13. The method of claim 9 Wherein X is an anion selected ?ltering step is suf?cient to keep the LiX in solution beloW
from nitrate, bromide, chloride, iodide, acetate, borate or close to saturation at the operating temperature.
(tetraborate), pentaborate, acetylsalicylate, amide, benZoate, 25 21. The method of claim 9 Wherein the ?rst ?ltering step
chlorate, perchlorate, chloroplatinate, chromate, citrate, is conducted at betWeen 0 and 120° C. and under atmo
dichromate, ?uosilicate, ?uosulfonate, formate, hydroxide, spheric or subatmospheric pressure.
hypochlorite, iodate, lactate, permanganate, methoxide, 22. The method of claim 9 Wherein the second ?ltering
molybdate, nitrite, niobate, oxalate, oxide, salicylate, step is conducted at betWeen 0 and 60° C. under atmospheric
sulfate, sul?de, sul?te, tartrate, thiocyanate, dithionate, 30
or subatmospheric pressure.
tungstate, and vanadate.
14. A method for preparing high purity lithium nitrate or 23. The method of claim 9 further comprising the step of
adding a sulfate salt having a monovalent cation to the
lithium bromide, comprising:
semiaqueous solution.
dissolving lithium chloride, lithium sulfate, or a mixture 24. The method of claim 23, Wherein said monovalent
thereof and a NaX salt, KX salt, or a mixture thereof, 35
cation sulfate salt is selected from Na2SO4, Na2SO4.10H2O,
Wherein X is nitrate or bromide, in an aqueous solution;
LiSO4, LiSO4.H2O, KLiSO4.1/2H2O, K2504, and
?ltering the solution to remove the sodium and potassium NaLiSO4.H2O.
salts: 25. A method for preparing lithium nitrate or lithium
adding an organic solvent selected from an aliphatic bromide, comprising:
ketone, an aliphatic alcohol and a mixture thereof, to reacting lithium salt selected from lithium chloride,
form a semiaqueous solution; lithium sulfate, and combinations thereof With NaX or
?ltering the precipitated sodium and potassium salts from KX, Wherein X is nitrate or bromide, in an aqueous
the semiaqueous solution; solution;
removing the organic solvent from the solution: and 45 adding an organic solvent to the aqueous solution to
recovering the resulting lithium nitrate or lithium bromide produce a semiaqueous solution; and
solution. removing the precipitated solids from the semiaqueous
15. The method of claim 9 further comprising the step of solution to obtain a LiX solution.
drying the LiX solution to form a LiX salt having a desired
level of purity.