Lithium aluminosilicate composites

Abstract

According to the present invention there is provided a composite particulate comprising a discontinuous phase and a binder; the discontinuous phase comprising a lithium aluminosilicate having a mean particle size in a range of about 2 to about 50 mm and having a lithium concentration of about 0.05 to about 5 wt.%; the binder comprising a sodium salt and / or a solid acid; a discontinuous phase to binder mass ratio of about 10:1 to about 1:1; and a particle size of about 25 to about 2000 mm.

Description

LITHIUM ALUMINOSILICATE COMPOSITESCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This disclosure claims the benefit of priority to AU Provisional Patent Application No. 2023904122, filed 19 December 2023, the entirety of which is incorporated herein.FIELD OF THE INVENTION

[0002] The present invention relates to the production of lithium carbonate from lithium containing particulates by the preparation and processing of lithium aluminosilicate composites.BACKGROUND

[0003] Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of common general knowledge in the field.

[0004] It is an object of the present invention to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

[0005] It is an object of a particularly preferred form of the present invention to provide for a composite particulate comprising a discontinuous phase and a binder, wherein the discontinuous phase comprises a lithium aluminosilicate and the binder comprises a sodium salt and / or a solid acid.

[0006] It is an object of another particularly preferred form of the present invention to provide for a core-shell composite particulate comprising a core having a lithium aluminosilicate composition and a shell having a sodium salt composition, and to an agglomeration of such core-shell particulates.

[0007] It is an object of another particularly preferred form of the present invention to provide for a process comprising providing lithium aluminosilicate microparticulates and fluidising the lithium aluminosilicate microparticulates while admixing the lithium aluminosilicate with a binder as a solution or a melt.

[0008] Although the invention will be described with reference to specific examples it will be appreciated by those skilled in the art that the invention may be embodied in many other forms.SUMMARY

[0009] A first embodiment is a composite particulate that includes a discontinuous phase and a binder; the discontinuous phase having a discontinuous phase lithium concentration of about 1 to about 4 wt.% and comprising spodumene having a spodumene mean particle size in a range of about 2 pm to about 50 pm; the binder comprising a sodium salt of a weak acid; the composite particulate having a discontinuous phase to binder mass ratio of about 10:1 to about 1 :1 ; and a composite particulate particle size of about 25 pm to about 2000 pm.

[0010] A second embodiment is a core-shell composite particulate that includes a spodumene core and a sodium-salt shell; where the shell has a thickness of about 25 nm to about 1 pm and includes sodium carbonate, sodium bicarbonate, sodium formate, sodium acetate, sodium oxalate, sodium tartrate, sodium citrate, or a mixture thereof; wherein the composite particulate has a Na:Li atomic ratio of about 1 :1 to about 10:1.

[0011] A third embodiment is a process that includes providing composite particulates that include an admixture of spodumene and sodium carbonate by fluidising spodumene microparticulates while admixing the spodumene microparticulates with a binder as a solution or a melt; wherein the binder adheres to surfaces of the spodumene microparticulates; pyrolyzing the composite particulates at a temperature of about 400 °C to about 1100 °C thereby providing a product admixture that includes lithium carbonate, sodium carbonate, and an analcime; and thereafter isolating the lithium carbonate.BRIEF DESCRIPTION OF THE FIGURES

[0012] For a more complete understanding of the disclosure, reference should be made to the following detailed description and accompanying drawing figures wherein:

[0013] Figure 1 is a representation of a composite particulate wherein the discontinuous phase depicted as circles with binder thereabout. The discontinuous phase comprises the lithium aluminosilicate as described above having a mean particle size in a range of about 2 to about 50 mm and having a lithium concentration of about 0.05 to about 5 wt.%, and the binder comprises the sodium salt and / or a solid acid as described above. Thecomposite particulate has a discontinuous phase to binder mass ratio of about 10:1 to about 1 :1 and a particle size of about 25 to about 2000 mm.

[0014] Figure 2 is another representation of a composite particulate with a smaller amount of binder. It will be appreciated that the amount of binder shown in Figure 2 is substantially less than is shown in Figure 1 . The discontinuous phase comprises the lithium aluminosilicate as described above having a mean particle size in a range of about 2 to about 50 mm and having a lithium concentration of about 0.05 to about 5 wt.%, and the binder comprises the sodium salt and / or a solid acid as described above. The composite particulate has a discontinuous phase to binder mass ratio of about 10:1 to about 1 :1 and a particle size of about 25 to about 2000 mm.

[0015] Figure 3 is a representation of a core-shell particle. The pores are designated (X) and may be covered by the shell (e.g., the left-hand pore, as shown) or uncovered by the shell (e.g., the right-hand pore, as shown).

[0016] Figure 4 is a schematic of a top spray fluidised bed coater. A top spray is preferred for agglomeration / granulation as required herein such that the process requires providing lithium aluminosilicate microparticulates having a mean particle size of about 2 to about 50 pm and having a lithium concentration of about 0.05 to about 5 wt.% and fluidising the lithium aluminosilicate microparticulates while admixing the lithium aluminosilicate with a binder as a solution or a melt. This causes the binder to adhere to surfaces of the lithium aluminosilicate microparticulates.

[0017] Figure 5 shows schematics of types of spray fluidised bed systems. It is envisaged that one or more of the arrangements shown is amenable to the process of the invention.

[0018] Figure 6 is a schematic of a continuous flow, top spray fluidised bed coater. This type of arrangement is considered especially applicable to conducting the process of the invention.

[0019] While specific embodiments are illustrated in the figures, with the understanding that the disclosure is intended to be illustrative, these embodiments are not intended to limit the invention described and illustrated herein.DETAILED DESCRIPTION

[0020] Objects, features, and advantages of the present invention will become apparent from the following detailed description. It should be understood, however, that the detailed description and the specific examples, while indicating specific embodiments of theinvention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the invention will become apparent to those skilled in the art from this detailed description.

[0021] Herein, the use of the word “a” or “an” when used in conjunction with the term “comprising” in the claims and / or the specification may mean “one,” but it is also consistent with the meaning of “one or more,” “at least one,” and “one or more than one.” The term “about” means, in general, the stated value plus or minus 5%. The use of the term “or” in the claims is used to mean “and / or” unless explicitly indicated to refer to alternatives only or the alternative are mutually exclusive, although the disclosure supports a definition that refers to only alternatives and “and / or.”

[0022] Unless the context clearly requires otherwise, the words “comprise”, “comprising”, “include”, “including” and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of “including, but not limited to”. As used herein, the phrase “consisting of excludes any element, step, or ingredient not expressly presented. When the phrase “consists of’ (or variations thereof) appears in a clause of the body of a claim, rather than immediately following the preamble, it limits only the element set forth in that clause; other elements are not excluded from the claim as a whole. As used herein, the phrase “consisting essentially of” limits the scope of a claim to the specified elements or method steps, plus those that do not materially affect the basis and novel characteristic(s) of the claimed subject matter.

[0023] With respect to the terms “comprising”, “consisting of, and “consisting essentially of, where one of these three terms is used herein, the presently disclosed and claimed subject matter may include the use of either of the other two terms. Thus, in some embodiments not otherwise explicitly recited, any instance of “comprising” may be replaced by “consisting of” or, alternatively, by “consisting essentially of”.

[0024] The recitation of a numerical range using endpoints includes all numbers subsumed within that range (e.g., 1 to 5 includes 1 , 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.).

[0025] The terms “preferred” and “preferably” refer to embodiments of the invention that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful and is not intended to exclude other embodiments from the scope of the invention.

[0026] This specification is prepared having regard to the principles of general application. As such, where the specification discloses a principle of general application, the claims may be drafted in correspondingly general terms (Biogen v Medeva

[1997] RPC 1 at48). A “principle of general application” is a general principle that can be practically applied in making a class of products, or in working a process, including where the claims define the products or processes in terms of the result to be achieved.

[0027] A first aspect of the present invention provides a composite particulate comprising a discontinuous phase and a binder; the discontinuous phase comprising a lithium aluminosilicate having a mean particle size in a range of about 2 to about 50 pm and having a lithium concentration of about 0.05 to about 5 wt.%; the binder comprising a sodium salt and / or a solid acid; the composite particulate having a discontinuous phase to binder mass ratio of about 10:1 to about 1 :1 ; and a particle size of about 25 to about 2000 pm.

[0028] The composite particulate comprises a lithium concentration of about 0.1 to about 4 wt.% and a mass ratio of the discontinuous phase to the binder of about 10:1 to about 1 :1 . The composite particulate is substantially free of water and consists essentially of (or consists of) the discontinuous phase and the binder. The composite particulate has a particle size of about 25 to about 1000 pm and exhibits a broadly spherical or spheroidal shape.

[0029] The discontinuous phase comprises a mineral or processed mineral selected from a spodumene, a petalite, a lepidolite, a clay, or a mixture thereof, preferably a 0- spodumene. Alternatively, the discontinuous phase comprises a lithium bearing clay.

[0030] The binder includes a sodium salt of a weak acid. The binder includes sodium carbonate, sodium bicarbonate, sodium formate, sodium acetate, sodium oxalate, sodium tartrate, sodium citrate, or a mixture thereof; preferably the binder includes sodium carbonate. Alternatively, or in combination, the binder includes a solid acid selected from oxalic acid, tartaric acid, citric acid, maleic acid, polyacrylic acid, or a mixture thereof.

[0031] The composite particulate comprises a Na:Li atomic ratio of about 1 :1 to about 10:1.

[0032] Exemplary embodiments are provided below, in Table 1 .Table 1: Exemplary embodiments of the inventive composite particulateSodium salt1 2-50 0.05-5and / or10:1 -1 :1 25-2000Solid acidSodium2 10 1.0 5:1 100 carbonate3 2 4.5 Oxalic acid 9:1 1500Sodium4 50 0.5 bicarbonate / 2:1 75Tartaric acid 1 :15 25 0.05 Sodium acetate 3:1 5006 15 2.5 Maleic acid 7:1 10007 30 0.1 Citric acid 1 :1 25

[0033] The second aspect of the present invention provides a core-shell composite particulate comprising: a core having a lithium aluminosilicate composition; and a shell having a sodium salt composition.

[0034] The shell has a thickness of about 25 nm to about 1 pm, about 25 nm to about 750 nm, or about 25 nm to about 500 nm. The shell is substantially discontinuous on the lithium aluminosilicate core. The discontinuity of the shell is defined by a surface coverage of between about 10% and about 90%. The shell interpenetrates the core via pores in the core. The shell includes sodium carbonate, sodium bicarbonate, sodium formate, sodium acetate, sodium oxalate, sodium tartrate, sodium citrate, or a mixture thereof. More preferably, preferably the shell includes sodium carbonate.

[0035] The core comprises a pegmatitic mineral, preferably a spodumene, more preferably a p-spodumene. The core has a mean particle size of about 2 to about 50 pm and has a lithium concentration of about 0.05 to about 5 wt.%. The core has a lithium concentration of about 0.05 to about 5 wt.%.

[0036] The core-shell composite comprises a Na:Li atomic ratio of about 1 :1 to about 10:1 , and is substantially as shown in Figure 3 of the accompanying drawings.

[0037] Exemplary embodiments are provided below, in Table 2.Table 2: Exemplary embodiments of the inventive core-shell compositeSodium100 40 9:1 carbonateSodium700 5 10:1 formateSodium400 75 7:1 oxalateSodium500 30 6:1 carbonate

[0038] The third aspect of the present invention provides an agglomeration of the core-shell composite particulates exemplified in Table 2, above.

[0039] The fourth aspect of the present invention provides a process comprising providing lithium aluminosilicate microparticulates having a mean particle size of about 2 to about 50 pm and having a lithium concentration of about 0.05 to about 5 wt.%; fluidising the lithium aluminosilicate microparticulates while admixing the lithium aluminosilicate microparticles with a binder as a solution or a melt; wherein the binder adheres to surfaces of the lithium aluminosilicate microparticulates.

[0040] A further aspect of the present invention provides a process that includes providing composite particulates that include an admixture of spodumene and sodium carbonate by fluidising spodumene microparticulates while admixing the spodumene microparticulates with a binder as a solution or a melt; wherein the binder adheres to surfaces of the spodumene microparticulates; pyrolyzing the composite particulates at a temperature of about 400 °C to about 1 100 °C thereby providing a product admixture that includes lithium carbonate, sodium carbonate, and an analcime; and thereafter isolating the lithium carbonate.

[0041] The binder adheres to a plurality of lithium aluminosilicate microparticulates thereby providing macroparticulates. The macroparticulates have a mean particle size of about 25 to about 2000 mm. The macroparticulates have a Na:Li atomic ratio of about 1 :1 to about 10:1. The macroparticulates are substantially free of water.

[0042] The lithium aluminosilicate is admixed with an aqueous solution of the binder. The lithium aluminosilicate and aqueous solution of the binder are admixed at a temperature of about 50 °C to about 200 °C. The lithium aluminosilicate and aqueous solution of the binder are admixed in a top spray fluidised bed coater. The process is continuous and further includes receiving a composite particulate of the first aspect of the invention (e.g., Table 1 ) or a core-shell composite particulate of the second aspect of the invention (e.g., Table 2).

[0043] Exemplary embodiments are provided below, in Table 3.Table 3: Exemplary embodiments of the inventive processMicroparticulates MacroparticulatesSodium salt and / or 50-1 2-50 0.05-5 25-2000 1 :1Solid acid 2002 10 1.0 75 Oxalic acid 50 5:13 2 4.5 1000 Citric acid 150 2:14 50 0.5 500 Sodium acetate 200 9:1Sodium5 25 0.05 100 bicarbonate / 75 10:1Tartaric acid 1 :16 15 2.5 1500 Sodium carbonate 125 7:17 30 0.1 25 Maleic acid 175 6:1

[0044] The second step of the inventive process requires fluidising the lithium aluminosilicate microparticulates while admixing the lithium aluminosilicate with a binder as a solution or a melt. This causes the binder to adhere to surfaces of the lithium aluminosilicate microparticulates (or macroparticulates). In practice, this is achieved through use of a top spray fluidised bed coater of the type shown in Figures 4-6.

[0045] In top spray coating, the spray liquid is sprayed onto the fluidising particles from above. To avoid agglomerate formation, the particles must have a larger diameter. The process is suitable, for example, for covering the surface of sticky products or for coloring particles. Products coated with the top spray process score with improved product handling and increased storage stability. Standard techniques of the art are applied, with process parameters such as flow rate or temperature toggled according to the physical and / or chemical characteristics of any lithium aluminosilicate feedstock.

[0046] Alternative representations of fluidised bed reactors applicable to the inventive process are shown as Figures 5 and 6 of the accompanying drawings.

[0047] A fifth aspect of the present invention provides for lithium aluminosilicate microparticulates or macroparticulates when coated with a binder (such as a sodium salt and / or a solid acid) by a process as defined in the fourth aspect of the invention. The coated microparticulates generally exhibit a physical profile as summarized in Table 1 , above. The coated macroparticulates are larger, having a mean particle size of about 25 to about 2000 pm.

[0048] In keeping with the aspects of the invention described above, a first embodimentis a composite particulate comprising a discontinuous phase and a binder. The discontinuous phase can have a discontinuous phase lithium concentration of about 1 to about 4 wt.% and comprises spodumene having a spodumene mean particle size in a range of about 2 pm to about 50 pm. Preferably, the binder comprises a sodium salt of a weak acid. The composite particulate, preferably, further includes a discontinuous phase to binder mass ratio of about 10:1 to about 1 :1 ; and has a composite particulate particle size of about 25 pm to about 2000 pm.

[0049] In some instances, the discontinuous phase lithium concentration can be about 1 wt.% to about 5 wt.% lithium. Preferably, the discontinuous phase lithium concentration is about 0.8, 0.85, 0.9, 0.95, 1 , 1.05, 1.1 , 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, 1.45, 1.5, 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, 1.85, 1.9, 1.95, 2, 2.05, 2.1 , 2.15, 2.2, 2.25, 2.3, 2.35, 2.4, 2.45, 2.5, 2.55,2.6, 2.65, 2.7, 2.75, 2.8, 2.85, 2.9, 2.95, 3, 3.05, 3.1 , 3.15, 3.2, 3.25, 3.3, 3.35, 3.4, 3.45, 3.5,3.55, 3.6, 3.65, 3.7, 3.75, 3.8, 3.85, 3.9, 3.95, 4, 4.05, 4.1 , 4.15, 4.2, 4.25, 4.3, 4.35, 4.4, 4.45,4.5, 4.55, 4.6, 4.65, 4.7, 4.75, 4.8, 4.85, 4.9, 4.95, 5.0 wt.% lithium or ranges and values therebetween.

[0050] The composite particulate can further include a Na:Li atomic ratio of about 1 :1 , 2:1 , 3:1 , 4:1 , 5:1 , 6:1 , 7:1 , 8:1 , 9:1 , or 10:1 . In a preferable instance, the Na:Li atomic ratio is between about 1 :1 to about 4:1 , or about 1.1 :1 to about 3:1 , or about 1 .25:1 to about 3:1 , or about 1.5:1 to about 3:1.

[0051] The spodumene can include a mean particle size of about 2 pm to about 1000 pm, about 2 pm to about 750 pm, about 2 pm to about 500 pm, about 2 pm to about 250 pm, about 2 to about 200 pm, about 2 to about 150 pm, or about 2 to about 100 pm. In certain examples, the mean particle size can be about 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 , 12, 13, 14, 15, 16, 17, 18, 19, 20, 21 , 22, 23, 24, 25, 26, 27, 28, 29, 30, 31 , 32, 33, 34, 35, 36, 37, 38, 39, 40, 41 , 42, 43, 44, 45, 46, 47, 48, 49, or about 50 pm or ranges and values therebetween.

[0052] The composite particulate further includes a composite particulate lithium concentration which is less than the discontinuous phase lithium concentration. In a preferable instance, the composite particulate lithium concentration is of about 0.1 to about 3.5 wt.%, about 0.2 to about 3 wt.%, or about 0.5 to about 3 wt.%. The composite particulate can further include a Na:U atomic ratio of about 1 :1 to about 5:1 .

[0053] In a preferable instance, the composite particulate is substantially free of water. In another instance, the composite particulate is free of water. Herein, the composite particulate being free of water can be determined by TGA analysis. In another preferable instance, the composite particulate consists essentially of or consists of the discontinuous phase and the binder. In still another preferable instance, the discontinuous phase comprises a-spodumene, p-spodumene, y-spodumene, or a mixture thereof; more preferably, the discontinuous phasecomprises p-spodumene.

[0054] The binder comprising a sodium salt of a weak acid can include sodium carbonate, sodium bicarbonate, sodium formate, sodium acetate, sodium oxalate, sodium tartrate, sodium citrate, or a mixture thereof. In one instance, the binder includes sodium carbonate; in another instance, the binder includes sodium bicarbonate. In still another instance, the binder further includes lithium carbonate. In still yet another preferable instance, the binder includes sodium carbonate and lithium carbonate.

[0055] Another embodiment is a core-shell composite particulate that includes a spodumene core and a sodium-salt shell. This composite particulate can include a shell that has a thickness of about 25 nm to about 1 pm and includes sodium carbonate, sodium bicarbonate, sodium formate, sodium acetate, sodium oxalate, sodium tartrate, sodium citrate, or a mixture thereof. Preferably, the composite particulate includes a Na:Li atomic ratio of about 1 :1 to about 10:1 .

[0056] In a preferable instance, the shell is substantially continuous, preferably is continuous, on the core thereby substantially or fulling enveloping the core material with the shell materials. In another preferable instance, the shell is discontinuous on the core, preferably covering a majority a core surface area but not fully enveloping the core materials. Still more preferably, the shell material interpenetrates the core via pores in the core, irrespective of the shell being continuous or discontinuous on the core material. In other instances, the surface coverage is between 15 and 85%, 20 and 80%, 25 to 75%, 30 to 70%, 35 to 65%, 40 to 60%, or 45 to 55%. In other embodiments, the surface coverage is at least 15%. 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75 or 80%. In some embodiments, the surface coverage is less than 85%, 80, 75, 70, 65, 60, 55, 50, 45, 40, 35, 30, 25 or 20%.

[0057] In one preferable instance, the shell includes sodium carbonate. In another preferable instance, the core comprises p-spodumene. In still another preferable instance, the shell includes sodium carbonate and the core includes p-spodumene. In still yet another preferable instance the shell consists essentially of or consists of sodium carbonate and the core consists essentially of or consists of p-spodumene.

[0058] In still another instance, the shell includes a proximal composition and a distal composition, wherein the proximal composition includes a sodium carbonate eutectic and the distal composition consists essentially of sodium carbonate. Herewith, proximal and distal are in relation to the core material, e.g., a proximal composition can be adjacent to and or interpenetrating the core while a distal composition can be carried upon the proximal composition but is not adjacent to the core. In one example, the sodium carbonate eutectic includes an admixture of sodium carbonate and lithium carbonate.

[0059] Still another embodiment is a process for the production and isolation of lithium carbonate. The process includes providing composite materials, e.g., those described above, pyrolyzing the composite materials thereby affecting a sodium for lithium exchange from the spodumene, and then isolating the lithium carbonate from the, now, sodium-containing rock. The process can include providing composite particulates that include an admixture of spodumene and sodium carbonate by fluidising spodumene microparticulates while admixing the spodumene microparticulates with a binder as a solution or a melt. Preferably, the binder adheres to surfaces of the spodumene microparticulates during the fluidization thereby providing composite macroparticulates having an average particle size larger than the spodumene microparticulates average particle size. The process further includes pyrolyzing the composite particulates at a temperature of about 300 °C to about 1100 °C, about 400 °C to about 1100 °C, about 500 °C to about 1100 °C, about 500 °C to about 1000 °C, about 500 °C to about 900 °C, or about 500 °C to about 800 °C, thereby providing a product admixture that includes lithium carbonate, sodium carbonate, and an analcime. The pyrolyzing (pyrolysis) temperature can be about 300, 325, 350, 375, 400, 425, 450, 475, 500, 525, 550, 575, 600, 625, 650, 675, 700, 725, 750, 775, 800, 825, 850, 875, 900, 925, 950, 975, 1000, 1025, 1050, 1075, 1100 °C or ranges and values therebetween..

[0060] In one example, the composite particulates include a spodumene to sodium carbonate mass ratio of about 10:1 to about 1 :1 ; and a composite particulate particle size of about 25 pm to about 2000 m. In another example, the composite particulates are core-shell composite particulates that include a spodumene core and a sodium-salt shell; where the shell has a thickness of about 25 nm to about 1 pm: and wherein the composite particulate has a Na:Li atomic ratio of about 1 :1 to about 10:1 .

[0061] In still another example, the binder includes sodium carbonate and, optionally, lithium carbonate, sodium bicarbonate, sodium formate, sodium acetate, sodium oxalate, sodium tartrate, sodium citrate, or a mixture thereof. Preferably, the binder includes sodium carbonate and lithium carbonate in a ratio of no less than about 2:1 , 4:1 , 5:1 , 6:1 , 7:1 , 8:1 , 9:1 , or 10:1. That is, the binder contains substantially more sodium carbonate than lithium carbonate. As described above, in one instance, the composite particulates include the lithium carbonate adjacent to the surface of the spodumene with a distal layer comprising, consisting essentially of, or consisting of sodium carbonate. Preferably, the composite particulates are substantially free of water.

[0062] The process of providing the composite macroparticulates can include admixing spodumene microparticulates with an aqueous solution of the binder and then removing the water. In one example, this process further includes comminuting the dried admixture of the spodumene microparticulates and binder thereby providing themacroparticulates. In another instance, the spodumene microparticulates and aqueous solution of the binder are admixed at a temperature of about 50 °C to about 200 °C thereby commixing the materials and removing the water in a single process step. In still another instance, the spodumene microparticulates and aqueous solution of the binder are admixed in a top spray fluidised bed coater thereby coating the spodumene with the binder and removing the water. Preferably, the coating process (and the entire process for producing the lithium carbonate) process is continuous or substantially continuous. In a particular example, the topspray fluidized bed coater includes a separation unit after a coating region thereby providing for a selection of a preferred particle size whereby oversized and undersized materials are processed and returned to the fluidized bed coater for reapplication of binder.

[0063] While the compositions and methods of this invention have been described in terms of preferred embodiments, it will be apparent to those of skill in the art that variations may be applied to the compositions and / or methods in the steps or in the sequence of steps of the method described herein without departing from the concept, spirit and scope of the invention. More specifically, it will be apparent that certain agents that are both chemically and physically related may be substituted for the agents described herein while the same or similar results would be achieved. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the invention as defined by the appended claims.

Claims

WHAT IS CLAIMED:1 . A composite particulate comprising a discontinuous phase and a binder; the discontinuous phase having a discontinuous phase lithium concentration of about 1 to about 4 wt.% and comprising spodumene having a spodumene mean particle size in a range of about 2 pm to about 50 pm; the binder comprising a sodium salt of a weak acid; the composite particulate having a discontinuous phase to binder mass ratio of about 10:1 to about 1 :1 ; and a composite particulate particle size of about 25 pm to about 2000 pm.

2. The composite particulate of claim 1 , further comprising a composite particulate lithium concentration of about 0.1 to about 3.5 wt.%.

3. The composite particulate of claim 1 , wherein the composite particulate is substantially free of water.

4. The composite particulate of claim 1 consisting essentially of the discontinuous phase and the binder.

5. The composite particulate of claim 1 , consisting of the discontinuous phase and the binder.

6. The composite particulate of claim 1 , wherein the discontinuous phase comprises 0- spodumene.

7. The composite particulate of claim 1 , further comprising a Na:Li atomic ratio of about 1 :1 to about 5:1 .

8. The composite particulate of claim 1, wherein the binder includes sodium carbonate, sodium bicarbonate, sodium formate, sodium acetate, sodium oxalate, sodium tartrate, sodium citrate, or a mixture thereof.

9. The composite particulate of claim 8, wherein the binder includes sodium carbonate.

10. The composite particulate of claim 8, wherein the binder further includes lithium carbonate.

11. A core-shell composite particulate comprising: a spodumene core and a sodium-salt shell; where the shell has a thickness of about 25 nm to about 1 pm and includes sodium carbonate, sodium bicarbonate, sodium formate, sodium acetate, sodium oxalate, sodium tartrate, sodium citrate, or a mixture thereof; wherein the composite particulate has a Na:U atomic ratio of about 1 :1 to about 10:1.

12. The core-shell composite particulate of claim 11 , wherein the shell is discontinuous on the core.

13. The core-shell composite particulate of claim 11 , wherein the shell interpenetrates the core via pores in the core.

14. The core-shell composite particulate of claim 11 , wherein the shell includes sodium carbonate.

15. The core-shell composite particulate of claim 11 , wherein the core comprises 3 spodumene.

16. The core-shell composite particulate of claim 11 , wherein the shell includes a proximal composition and a distal composition, wherein the proximal composition includes a sodium carbonate eutectic and the distal composition consists essentially of sodium carbonate.

17. The core-shell composite particulate of claim 16, wherein the sodium carbonate eutectic includes an admixture of sodium carbonate and lithium carbonate.

18. A process comprising: providing composite particulates that include an admixture of spodumene and sodium carbonate by fluidising spodumene microparticulates while admixing the spodumene microparticulates with a binder as a solution or a melt; wherein the binder adheres to surfaces of the spodumene microparticulates; pyrolyzing the composite particulates at a temperature of about 400 °C to about 1100 °C thereby providing a product admixture that includes lithium carbonate, sodium carbonate, and an analcime; and thereafter isolating the lithium carbonate.

19. The process of claim 18, wherein the composite particulates include a spodumene to sodium carbonate mass ratio of about 10:1 to about 1 :1 ; and a composite particulate particle size of about 25 pm to about 2000 pm.

20. The process of claim 18, wherein the composite particulates are core-shell composite particulates that include a spodumene core and a sodium-salt shell; where the shell has a thickness of about 25 nm to about 1 pm: and wherein the composite particulate has a Na:Li atomic ratio of about 1 :1 to about 10:1 .21 . The process of claim 18, wherein the binder includes sodium carbonate and, optionally, lithium carbonate, sodium bicarbonate, sodium formate, sodium acetate, sodium oxalate, sodium tartrate, sodium citrate, or a mixture thereof.

22. The process of claim 18, wherein the composite particulates are substantially free of water.

23. The process of claim 18, wherein the spodumene microparticulates are admixed with an aqueous solution of the binder.

24. The process of claim 23, wherein the spodumene microparticulates and aqueous solution of the binder are admixed at a temperature of about 50 °C to about 200 °C.

25. The process of claim 24 wherein the spodumene microparticulates and aqueous solution of the binder are admixed in a top spray fluidised bed coater.

26. The process of claim 25 wherein the process is continuous or substantially continuous.

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