TWI548593B - Treated ammonium octamolybdate composition and methods of producing the same - Google Patents

Description

Processed ammonium octamolybdate composition and method of making the same Cross-reference to related patent applications

This patent application claims to have the benefit of the U.S. Patent Provisional Application Serial No. 61/907,856, filed on Nov. 22, 2013, entitled "Processed Ammonium Octa Molybdate Composition and Method of Making the Composition", Borrowing All disclosures are incorporated herein by reference.

Field of invention

The present invention is largely directed to the manufacture of ammonium octamolybdate compositions and, more particularly, to the manufacture of ammonium octa molybdate powder compositions for formulating optically marking inks and polymers.

Background of the invention

Ammonium octa molybdate, (NH ₄ ) ₄ Mo ₈ O ₂₆ or "AOM", is a commercial molybdenum composition and may have various phases or isomers. The compound called ammonium octamolybdate is commonly referred to as "diammonium catena-tetramolybdate", "ammonium tetramolybdate", "tetraammonium hexamolybdate", or abstract number 12411-64 -2. The most important here is alpha phase or "a-AOM", but other phases are known to exist and can be used in certain applications.

α-AOM is usually produced by thermal decomposition of ammonium dimolybdate, (NH ₄ ) ₂ Mo ₂ O ₇ or "ADM". The thermal decomposition process occurs according to the following basic chemical reactions: (1) 4(NH ₄ ) ₂ Mo ₂ O ₇ + heat → α-(NH ₄ ) ₄ Mo ₈ O ₂₆ +4NH ₃ +2H ₂ O

Alternatively, α-AOM may also be produced from water or wet process, for example, disclosed in U.S. Patent No. 4,762,700, entitled "α - octamolybdate", by citing its entirety is incorporated herein disclosed.

Although α-AOM is commonly used as a smoke suppressant in various types of plastics, it can also be used to formulate various optically labeled ink compositions. Such ink compositions can react to light, typically from lasers, to change color, but other sources can be used. Changing the color causes a change in the oxidation state and/or a chemical amount ratio product of the AOM component in the ink composition.

A number of AOM-based optical labeling compositions or inks are disclosed in U.S. Patent Nos. 7,485,403 and 8,048, 605, the entire disclosure of each of each of each of each of Briefly, the ink compositions disclosed in the '403 and '605 patents contain oxygen ions of a polyvalent metal, a solvent, and a binder. Oxygen ions of polyvalent metals include AOM and especially alpha-AOM, but can also be identified from other materials. The solvent comprises any solvent which is commonly used in inks and paints, such as water, ethanol, ethyl acetate, isopropanol, and hydrogen compounds. The binder is typically a polymer and comprises acrylic acid, cellulose, polyvinyl alcohol, polyester, and the like. The binder further includes an unstable group such as a hydroxyl group, an acetate group, an acetal ether, or a halogen. The disclosed ink compositions can also include a number of additional additives and compositions as described in the patent documents, depending on a wide range of factors and desired ink characteristics.

In general, by mixing the right amount of AOM, solvent and bonding The agent material is formed into a paint to form the various ink or optical marking compositions. The paint is then applied to the marked material (eg paper or cardboard) and allowed to dry. The actual marking or imaging process can be accomplished by directing a suitable wavelength of light (e.g., a laser beam) onto the coating ink, thereby changing the color of the ink to form the desired image.

In addition to ink, the cited patent teaches that AOM can also be incorporated directly into various types of polymers, such as nylon, polyester, polyamide, polycarbonate, polyacrylate, polymethyl acrylate, ABS polymer, Polyolefins and the like, which can then be directly labeled as needed in accordance with methods similar to those used for inks.

Summary of invention

A treatment method comprising the steps of: providing an initial supply of an ammonium octa molybdate precursor having a bimodal particle size distribution; applying a quantity of a solvent to the initial supply of the ammonium octamolybdate precursor to form a wet An intermediate powder; and the wet intermediate powder is allowed to adsorb the applied solvent over a period of time, the amount of the applied solvent and the period of time sufficient to form a treated ammonium octamolybate powder having a substantially monomodal particle size distribution Body composition.

Also disclosed is an ammonium octamolybdate composition prepared by adding an appropriate amount of water to an initial supply of an ammonium octa molybdate precursor powder having a bimodal particle size distribution and by allowing the initial supply of the ammonium octamolybdate powder The added water is adsorbed for a period of time sufficient to produce a treated ammonium octa molybdate powder composition having a single peak particle for a period of time sufficient to produce a treated ammonium pentamolybdate powder composition Path distribution.

Also disclosed is an improved optically-labeled ink composition comprising an oxyanion of a polyvalent metal, a solvent, and a binder, wherein the improvement comprises utilizing an eight having a substantially monomodal particle size distribution The ammonium molybdate powder is used as an oxyanion of a polyvalent metal, and the ammonium octamolybdate powder system is initially supplied by applying a quantity of a solvent to an ammonium octa molybdate precursor powder to form a wet intermediate powder, and allowing The wet intermediate powder adsorbs the applied solvent over a period of time, and the amount of the applied solvent and the period of time is sufficient to form a treated ammonium octa molybdate powder composition having a substantially monomodal particle size distribution.

In another embodiment, a processing method can include: providing an initial supply of an ammonium octa molybdate precursor powder having a bimodal particle size distribution; providing an intermediate adsorbent; applying a quantity of a solvent to the intermediate adsorbent To produce a solvent-containing intermediate adsorbent; the solvent-containing intermediate adsorbent and the initial supply of the ammonium octamolybdate precursor powder are placed in a container; the container is sealed; and the initial ammonium octa molybdate powder is allowed to be initialized The feed is adsorbed over a period of time to the solvent desorbed from the intermediate adsorbent, the amount of the solvent and the period of time being sufficient to form a treated ammonium octa molybdate powder composition having a substantially monomodal particle size distribution.

In still another embodiment, a treatment method can include: providing an initial supply of an ammonium octa molybdate precursor having a bimodal particle size distribution and having a residual moisture of at least about 0.1% by weight when measured by loss on drying; The initial supply of the ammonium octamolybdate precursor powder is placed in a container; the container is sealed; and the sealed container is heated to a temperature of at least about 30 ° C for a period of time sufficient to form a substantially monomodal particle size distribution. Treatment of ammonium octamolybdate powder composition Things.

10, 110, 210‧‧‧ method

12, 112, 212‧‧ ‧ treated AOM composition

14‧‧‧α-AOM precursor material

16‧‧‧Bimodal particle size distribution

18‧‧‧First mode peak

20‧‧‧second mode peak

22, 122‧‧‧ solvent

24, 124‧‧‧ Wet intermediates

25‧‧‧Atomized water

26‧‧‧Atomizing nozzle

28‧‧‧Steam

30‧‧‧Steam generator equipment

32‧‧‧ steam outlet

34‧‧‧Rotating drum

36‧‧‧ unimodal particle size distribution

38‧‧‧ single peak

40‧‧‧Roller

42‧‧‧Axis

44‧‧‧Drive motor

46‧‧‧Rotation direction

48‧‧‧Paddles

50‧‧‧ inner surface

52‧‧‧ heating device

54, 154‧‧‧ Dryer

56, 156, 256‧‧‧ additional grinding steps

114, 214‧‧‧AOM precursor material

123‧‧‧Intermediate adsorbent

125‧‧‧ breathable bag

135‧‧‧ sealed container

235‧‧‧ container

253‧‧‧heating steps

Exemplary and presently preferred embodiments of the present invention are illustrated in the drawings, which are: FIG. 1 is a schematic diagram showing the basic process steps in a specific embodiment of the processed ammonium octamolybdate composition; The peak particle size distribution generally has a particle size distribution histogram of the commercially available standard ammonium octamolybdate precursor material and a cumulative distribution map of the undersize material; FIG. 3 is a composition of the treated octaammonium molybdate powder having a unimodal particle size distribution. The histogram of the particle size distribution and the cumulative distribution of the undersize material; Figure 4 is a scanning electron micrograph of a typical octa molybdate precursor material magnified 2000x; Figure 5 is a treatment of the ammonium octamolybdate powder composition 2000x Scanning electron micrograph; Figure 6 is a histogram of the particle size distribution of the "ultrafine grinding" ammonium octamolybdate precursor material and the cumulative distribution of the undersize material; Figure 7 is a part of the experimental 1 fluidized bed steaming process The histogram of the particle size distribution of the ammonium octamolybdate powder composition and the cumulative distribution of the undersize material; Fig. 8 is the particle size distribution of the composition of the treated ammonium octamolybdate powder in the fluidized bed steaming method of test 2 Figure and the cumulative distribution of the undersize; Figure 9 is the test 3 flow Steaming in a bed of treated powder octamolybdate composition, and a particle size distribution histogram of cumulative undersize distribution; Figure 10 (ab) is a histogram of the particle size distribution of the second and third sample portions of the treated ammonium octamolybdate powder composition in the fluidized bed steaming method of Test 4, and the cumulative distribution map of the corresponding undersize materials; Figure 11 (ac) is a histogram of the particle size distribution of the first, second and third sample portions of the treated ammonium octamolybdate powder composition in the fluidized bed steaming method of Test 5; and the cumulative distribution map of the corresponding undersize materials; The 12 series is used for the particle size distribution histogram of the ammonium octamolybdate precursor powder material in the steaming method of the rotary dryer and the cumulative distribution map of the undersize material; FIG. 13 is a method prepared by the rotary dryer steaming method. The histogram of the particle size distribution of the composition of the ammonium octamolybdate powder and the cumulative distribution of the undersize of the sieve; FIG. 14 is a histogram of the particle size distribution of the precursor powder of the ammonium octamolybdate pretreated in the solvent spray method and Figure 15-18 is a histogram of the particle size distribution of the composition prepared in the solvent spray method of Test 1-4 and the cumulative distribution of the corresponding undersize material; Figure 19 is the production of treated ammonium octamolybdate Schematic diagram of the basic process steps in another specific embodiment of the composition method; Figure 20 is a manufacturing process A schematic diagram of the basic process steps in yet another embodiment of the ammonium octamolybdate composition method; and FIG. 21 is a histogram of the particle size distribution of the composition prepared by the intermediate adsorbent method illustrated in FIG. 19 and under the sieve Accumulated distribution map.

Detailed description of preferred embodiments

Figure 1 shows a treated ammonium octamolybdate composition 12 treatment method Various embodiments of 10 and it relate to providing an initial supply of ammonium octamolybdate (AOM) precursor powder 14. In a typical embodiment, the ammonium octamolybdate precursor powder 14 comprises alpha-AOM powder produced by thermal decomposition of ammonium dimolybdate (ADM). The alpha-AOM precursor powder 14 comprises a substantially bimodal particle size distribution 16 having two modal peaks 18 and 20, which can be seen more clearly in FIG. A solvent 22, such as water, can then be applied to the initial supply of the ammonium octamolybdate precursor 14 to form the wet intermediate powder composition 24.

As will be described in more detail herein, the solvent 22 can be in liquid or gaseous (i.e., gaseous) form and added or applied to the initial supply of the AOM precursor powder 14 in a variety of ways to form the wet intermediate powder composition 24 . For example, in one embodiment, the solvent 22 can be added to the AOM precursor powder 14 in a liquid state (e.g., by atomizing liquid stream 25 produced by one or more atomizing nozzles 26) to evenly distribute the solvent 22 The entire AOM precursor powder 14 . In an alternative embodiment, the solvent 22 may be first vaporized, i.e., converted to steam 28 by the steam generator apparatus 30 (in a particular embodiment the solvent 22 is water). The steam 28 is then applied to the AOM precursor powder 14 (eg, via one or more ports 32) to form a wet intermediate powder composition 24.

In some embodiments, it is preferred to roll or agitate the initial supply of AOM precursor powder 14 during the wetting process to promote more uniform (i.e., liquid or vapor form) application of the solvent 22 to the AOM. Quality powder 14. In one embodiment, a canister drum apparatus 34 can be used to flip or roll the AOM precursor powder 14 when the solvent 22 is used. Alternatively, other configurations are possible, as will be described in further detail herein.

Application of solvent 22 (ie, in liquid or vapor form) as described The initial supply of AOM precursor powder 14 can result in the formation of wet intermediate powder composition 24. The wet intermediate powder composition 24 is then allowed to adsorb the application solvent 22 for a period of time sufficient to produce the treated AOM composition 12. Some of the physical properties of the AOM precursor powder 14 are significantly altered during the adsorption process. For example, the particle size distribution of the AOM precursor powder 14 during solvent adsorption is altered or converted from a substantially bimodal particle size distribution 16 having two modal peaks 18 and 20 (Fig. 2) to a single peak 38. A substantially monomodal particle size distribution 36. Please see Figure 3.

In addition to changing or shifting its particle size distribution characteristics, it has been considered that the treatment method 10 of the present invention also results in a change in the surface morphology or structure of the individual particles of the treated AOM composition 12. For example, and now referring first to Figures 4 and 5, scanning electron micrographs of untreated AOM precursor powder 14 (Figure 4) and treated AOM composition 12 (Figure 5) show some changes in the surface structure of individual particles. . This surface structure change is currently believed to have some effect on improving the performance of the treated AOM composition 12 of the present invention when used to form optically marking inks and polymers.

Turning now first to Figure 1, the wet intermediate 24 can be further processed, if desired, prior to being identified as the final treated AOM composition 12. For example, the wet intermediate 24 can be further heated and/or dried in an oven or dryer 54 to further reduce any residual moisture content possible in the intermediate product 24. The intermediate product 24 can also be subjected to an additional grinding or grinding step 56 to break up any large agglomerates that may form during the processing. The grinding or milling step 56 can be carried out on the untreated intermediate product 24 or the dried intermediate product from the dryer 54.

Thereafter, the final treated AOM composition 12 can be used to make an AOM-based optical marking ink and polymer composition. The treated AOM composition 12 can be used to replace all of the conventional AOMs required for a particular formulation to improve the performance of the ink and/or polymer composition.

A significant advantage of the processing method of the present invention is that a treated AOM composition 12 having improved properties can be produced when used to fabricate AOM-based optical marking inks and polymers. For example, the treated AOM composition 12 of the present invention can improve the viscosity properties of the ink lacquer composition made from the treated AOM composition 12. More specifically, the use of the treated AOM composition 12 can result in an ink lacquer or composition that is generally lower than typically achievable with conventional AOM compositions. The lower viscosity ink composition prepared by the treated AOM composition 12 of the present invention is obviously added to the additional liquid or other viscous modifier which adversely affects the performance of the dry ink during the ink mixing stage. Lower viscosity. In addition, the use of the treated AOM composition 12 can also improve its ability to form an ink composition after the optical marking process. Such improved properties include, but are not limited to, visual color (ie, "whiteness") and optical density properties.

Moreover, the particle size distribution which can be easily and immediately converted from bimodal 16 or changed to a single peak 36 by the treatment method described herein is also advantageous in that it is difficult to achieve the desired single peak distribution by conventional methods (for example, By smashing and/or sorting). For example, as described above, an ammonium octamolybdate composition generally used for optically marking ink contains an α type (i.e., α-AOM) which is produced by thermal decomposition of ammonium dimolybdate (ADM). Thermal decomposition of α-AOM typically exhibits a bimodal particle size distribution 16 having two modal peaks 18 and 20, as shown in Figure 2. See more clearly. Again, these modal peaks typically occur at particle sizes of about 1 [mu]m and 10 [mu]m. The particle size of 1 μm is extremely small, generally belonging to particles contained in cigarette smoke, and cannot be easily removed from large particles. On the other hand, 10 μm particles can be reduced in size by various types of grinding or grinding methods, and small particles of less than 10 μm are not practical for such grinding or grinding in most applications. A more complicated comminution or classification is that the alpha-AOM powder is generally less prone to flow, which will cause difficulties in handling the powder in such processes.

Also apparently, preliminary tests have shown that the unimodal particle size distribution 36 (Fig. 3) of the treated AOM composition 12 of the present invention may not be the only factor leading to improved performance of the optically marking ink composition 12 of the present invention. For example, conventional AOM materials that have been additionally processed and classified to achieve a substantially monomodal particle size distribution do not result in optically marking inks having improved performance of the treated AOM composition 12 of the present invention. In other words, there is a significant difference between the treated and untreated AOM compositions, even though the latter has been further processed to achieve a single peak or near peak particle size distribution of the treated AOM composition 12.

As previously described, it is currently believed that improving the performance of the treated AOM composition 12 of the present invention (compare untreated AOM) is also due in part to the morphological change of the individual particle structure of the treated AOM composition 12. Please see Figures 4 and 5. Although the specific structural basis for improving the performance of the treated AOM 12 is not fully understood at this time, as identified herein, achieving these advantages is primarily a consideration of many process steps.

Yet another important feature of the treated AOM composition 12 of the present invention is that the treated AOM composition 12 exhibits substantially the same anhydrous loss on ignition ("an-LOI") as the untreated AOM composition. Waterless loss The magnitude is an important parameter for forming an optically marking ink composition. The ability to maintain near the same anhydrous loss on ignition in the treated AOM composition 12 of the present invention represents yet another additional advantage of the treated AOM composition 12 of the present invention.

Various specific embodiments for making or producing the treated AOM powder composition 12 of the present invention, as well as some of the more important attributes and advantages associated with the manufacture of optically labeled inks and polymers, have now been described, now Various preferred embodiments of the method of manufacturing the treated AOM composition 12 will be described in detail. However, it should be noted that, unless otherwise stated, the following description or claimed method should not be construed as limited to any particular operational parameters, including the number of reagents, the order in which the reagents are added, the reaction conditions, and other values. Again, it must be noted that specific reaction parameters and other operational factors can be optimized in a given situation (taking into account environmental factors, production level requirements, etc.) in a given preliminary small test. The discussion herein refers to one or more preferred embodiments that are designed to provide the best results but are not limiting or limiting.

Referring now first to Figures 1 and 2, a method 10 of making a treated ammonium molybdate composition 12 can include providing an initial supply of an ammonium octa molybdate (AOM) precursor material 14. As previously stated, compounds known as ammonium octamolybdate are also commonly referred to as "diammonium catena-tereamolybdate", "ammonium tetramolybdate", "tetraammonium hexamolybdate", Or CAS number 12411-64-2. Thus, as used herein, the term "AOM" shall be taken to include the compounds of these various other known names. In a specific embodiment, the AOM precursor material 14 comprises an alpha-type ammonium octaammonium molybdate (a-AOM) powder material made by thermally decomposing ammonium dimolybdate (ADM) as described herein. The thermally decomposable alpha-AOM is readily available from a number of supplier sources. By way of example, in various embodiments and examples shown and described herein, the AOM precursor powder material 14 comprises a thermally decomposable alpha-AOM powder material manufactured by Climax Molybdenum Company of Fort Madison, USA.

The α-AOM precursor powder material 14 produced by Climax Molybdenum Company contains a fine powder having a bimodal particle size distribution of 16 having two modal peaks 18 and 20, which can be seen more clearly in FIG. Before the description, it must be pointed out that the term "bimodal" as used herein refers to two patterns that appear as particle size layered or difference maps or as local maxima in individual particle size histograms or histograms. State peak particle size distribution. Similarly, the term "single peak" refers to a particle size distribution comprising a single modal peak or a maximum value appearing in a particle size map or in a respective particle size histogram. In addition, it must be noted that the particle size distribution map shown and described herein is produced by one of two different types of liquid dispersion type laser particle size analyzers, as clearly indicated in the Examples section. The first type of analyzer is the Model 1180 Cilas laser particle size analyzer manufactured by Compagnie Industries, Inc. (Cilas, France). The second type of analyzer is a Microtrac particle size analyzer of the model S3000/S3500 manufactured by Microtrac Co., Ltd., Montgomeryville, PA.

Continuing with the description, the bimodal particle size distribution 16 of the α-AOM precursor material 14 utilized herein is included in the first mode peak 18 and from about 6- from a particle size range of about 1-4 μm (typically about 2 μm). A second mode peak of 20 in the 10 [mu]m (typically about 8 [mu]m) particle size range. A scanning electron micrograph of an alpha-AOM precursor powder material 14 is shown in FIG.

After providing an appropriate amount of AOM precursor material 14, a solvent 22 can The initial charge to the precursor material 14 is then applied to form or make the wet intermediate product 24. In a specific embodiment, the solvent 22 comprises deionized water and can be added in an amount sufficient to produce a treated AOM composition having a desired monomodal particle size distribution. Alternatively, other types of solvents 22 may be added, for example various alcohols and hydrocarbon compounds may also be used. In a particular embodiment where the solvent 22 comprises deionized water, the deionized water is sufficient for this purpose to be applied in an amount from about 0.1% to about 1% by weight, preferably from about 0.25% to about 0.5% by weight. And, preferably, the initial charge of about 0.5% by weight of the precursor material 14.

The solvent 22 can be applied in liquid form or as a gas or vapor (e.g., steam 28). It is presently believed that the application of the solvent 22 to the AOM precursor material 14 (i.e., in liquid or vapor form) causes the smaller particles to interconnect or cohesive via a capillary agglomeration mechanism. Capillary coacervation is the result of the hydrophilicity of the AOM precursor material 14 and the relationship between high surface area and low gas volume at the interparticle position. The condensable moisture content depends on the angle formed between the two particle surfaces and the available moisture content. Once sufficient moisture (i.e., in liquid or vapor form) is present, the solvent will dissolve in the material. AOM has a solubility limit of about 4 grams per liter (g/l) in 25 ° C water and should increase with temperature. When the fog is in moisture, then a small AOM "bridge" will form between the particles, which will be bonded together after drying, with sufficient strength to hold together.

We have found that the addition of about 0.5% by weight of water provides sufficient agglomeration of smaller particles to convert the bimodal particle size distribution 16 (Fig. 2) of the α-AOM precursor powder 14 to a unimodal particle size distribution 36 (Fig. 3) without Increase the formed processing The water loss on ignition ("an-LOI") of the AOM composition 12. For example, the treated alpha-AOM compositions of the present invention comprise an an-LOI value ranging from about 8% to about 8.8%. However, the addition of solvent 22 can nominally increase the loss on drying (LOD) value of the treated AOM composition 12 formed.

The solvent 22 can be applied to the AOM precursor material 14 in any of a variety of ways, as previously described. In a specific embodiment, the solvent 22 (eg, water) can be added or applied to the AOM precursor material 14 in liquid form by injecting it through one or more spray nozzles 26 located adjacent the AOM precursor material 14. The initial feed, as seen in Figure 1, can be seen more clearly. The spray nozzle 26 separates the liquid solvent 22 (e.g., water) into fine droplets to form an atomized stream 25. The dispersion of liquid water becomes one or more atomizing streams 25 to cause liquid water (i.e., in the form of atomized droplets) to be more evenly distributed over the AOM precursor material 14.

Depending on the manner in which the AOM precursor material 14 is used for processing, that is, the AOM precursor material 14 is unrolled in a thin layer of material or provided in the form of a large layer containing a thick layer, which is preferred or advantageously agitated during the application of the solvent or The AOM precursor material 14 is tumbled to ensure a more uniform application of the solvent 22 to the overall precursor powder 14. In a specific embodiment, such agitation or tumbling can be accomplished by placing the AOM precursor powder 14 in a drum apparatus 34.

For example, the drum apparatus 34 includes a large, elongated cylindrical container or drum 40 that is mounted for rotation about a shaft 42. A drive motor 44 associated with operation of the drum 40 can rotate the drum 40 about the shaft 42 in a direction generally indicated by arrow 46. One or more paddles or paddles 48 are provided on the inner surface 50 of the drum 40 to lift and flip the AOM precursor powder when the drum 40 is rotated. 14. Thus, the particles of the new precursor powder 14 are exposed to the atomizing solvent 22 discharged from the nozzle 26.

In another embodiment, the solvent 22 can be applied to the AOM precursor material 14 by first evaporating the solvent 22, i.e., converting it to steam 28. A suitable steam generating device 30 can be used for this purpose. The steam 28 can then be applied to the AOM precursor powder 14 via one or more ports 32 disposed adjacent the precursor material 14. In a particular embodiment, the port 32 can be disposed within the drum apparatus 34 to ensure more uniform exposure of the precursor material 14 to the steam 28.

In some embodiments, the precursor material 14 is preferably heated during the solvent application process. If so, the drum unit 34 also needs to be equipped with one or more heating devices 52. The heating device 52 can be activated during the solvent application process to provide the desired amount of heat during the desired time. For example, in one embodiment, the heating and application steam can be applied simultaneously or in an alternating manner to produce the treated AOM composition 12. If a heating mode is to be used, the temperature range used is from about 80 ° C to about 105 ° C (more preferably about 100 ° C).

The application of the initial supply of solvent 22 to the AOM precursor powder 14 results in the formation of a wet intermediate powder composition 24. The wet intermediate powder composition 24 is then allowed to adsorb the applied solvent 22 for a period of time sufficient to produce the treated AOM composition 12 as previously described. In general, a time period of at least about 12 hours, and more preferably from about 48 hours to about 96 hours, will suffice for this purpose. Certain physical properties of the AOM precursor powder are significantly altered during the solvent adsorption process. For example, when the solvent is adsorbed by the AOM precursor powder 14, the particle size distribution of the AOM precursor powder 14 has two modal peaks 18 The substantially bimodal particle size distribution 16 of 20 and (Fig. 2) is altered or converted to a substantially monomodal particle size distribution 36 having a single peak 38 (Fig. 3). In general, the treated AOM composition 12 will have a single peak 38 having a diameter ranging from about 4 [mu]m to about 12 [mu]m, preferably ranging from about 6 [mu]m to about 10 [mu]m, and more preferably about 8 [mu]m in diameter. We have found that the unimodal particle size distribution is more important than the specific position of the single mode peak. For example, single mode peak samples having a range from about 6 [mu]m to about 10 [mu]m all provide the described improvement in performance.

In addition to changing or converting the particle size distribution characteristics (i.e., from substantially bimodal 16 to substantially a single peak 36), it is contemplated that the processing method 10 can also result in surface morphology or structure of the individual particles of the treated AOM composition 12. change. For example, and now referring first to Figures 4 and 5, the scanning electron micrograph (Fig. 4) of the untreated AOM precursor powder 14 and the treated AOM composition 12 (Fig. 5) show that some changes have taken place in the surface structure of the individual particles. . It is currently believed that changes in surface structure have some effect on the performance improvement of the treated AOM composition 12 when used to form optically marking inks and polymers.

As previously described, method 10 may alternatively involve additional processing steps to wet intermediate material 24. For example, the wet intermediate 24 may be further heated and/or dried in an oven or dryer 54. Such additional heating can further reduce the extent of any residual moisture that may be contained in the intermediate product 24 and can also be used to reduce the dry weight loss (LOD) quality criteria of the treated AOM composition 12. If used, such heating can be carried out at any wide temperature range sufficient to release moisture, for example, when water is used as solvent 22, the temperature ranges from about 80 ° C to about 100 ° C.

In addition, the intermediate product 24 can also be additionally ground or ground. Step 56, with or without additional heating step 54, to break up any bulk agglomerates that may form during the process.

In this regard it must be noted that certain variations of the particular processing steps and processing parameters in the method 10 can be used to alter or modify certain properties of the processed AOM composition 12 as needed or desired in certain applications. For example, the use of steam 28 instead of atomized water during solvent application generally results in a treated AOM composition 12 having a slightly smaller maximum particle size. The use of steam 28 also reduces the particle size associated with the second mode peak 20 of the treated material 12. Moreover, the application of heat, while not necessary to manufacture the treated AOM composition 12, can reduce the time period required to manufacture the treated AOM composition 12. The application of heat, during the application of the solvent process or to the wet intermediate product 24 formed therefrom, may also reduce the dry weight loss (LOD) quality criteria of the final treated AOM composition 12, and may be desirable for certain applications.

In another embodiment 110, shown in FIG. 19, solvent 122 can be applied to the AOM precursor material 114 by an intermediate adsorbent 123. More specifically, solvent 122 can be applied to intermediate adsorbent 123 to form solvent-containing intermediate adsorbent 123. The solvent-containing intermediate adsorbent 123 can then be placed in a gas permeable container or bag 125. Thereafter, the solvent-containing intermediate adsorbent 123 (along with the venting bag 125, if used) can then be placed in a container 135 with an amount of AOM precursor material 114. The container 135 is then sealed (eg, to be substantially airtight). The solvent 122 from the solvent-containing intermediate adsorbent 123 is gradually desorbed from the intermediate adsorbent 123 (and through the gas permeable container or bag 125) before being adsorbed by the AOM precursor material 114 to form a wet intermediate powder composition 124. If used). The desorption/adsorption process allows This is continued for a period of time sufficient to produce a treated AOM composition 112. During the desorption/adsorption process, the particle size distribution of the AOM precursor powder material 114 is altered or converted from a substantially bimodal particle size distribution to a substantially monomodal particle size distribution.

As with the other embodiments, solvent 122 can comprise a wide variety of materials, such as water, alcohol, or hydrocarbon materials. The intermediate adsorbent 123 can comprise a wide variety of materials suitable for use in adsorbing a particular solvent 122 and thereafter desorbing or releasing a substantial amount of solvent 122 when placed in a sealed container 135. For example, in one embodiment the solvent 122 comprises deionized water and an intermediate adsorbent 123 comprising amorphous precipitated alumina (i.e., "silicone"). The solvent 122 (e.g., deionized water) and the silica adsorbent 123 should be in an amount sufficient to allow a large amount of solvent 122 to be desorbed from the adsorbent 123 and subsequently adsorbed by the AOM precursor material 114 to produce the treated AOM composition 112. Provided. In general, the amount of intermediate adsorbent 123 having adsorbent solvent 122 (e.g., water) is sufficient to account for from about 0.3% to about 0.5% by weight of the total amount of AOM precursor material 114 to be treated.

As in the case of method 10, the method 110 may alternatively involve additional processing steps. For example, the wet intermediate 124 can be further heated and/or dried in an oven or dryer 154 to further reduce any residual moisture content possible in the intermediate product 124 and/or to further reduce the drying weight loss of the treated AOM composition 112 ( LOD) quality standard. If used, such heating can be carried out over any wide temperature range sufficient to release moisture, for example, when deionized water is used as solvent 122, the temperature ranges from about 80 °C to about 100 °C.

The intermediate product 124 can also be subjected to an additional grinding or grinding step 156 with or without additional heating step 154 to break up any bulk agglomerates that may form during the processing.

In still another embodiment 210, shown in Figure 20, the AOM composition is processed by heating an amount of AOM precursor material 214 for a period of time sufficient to change the particle size distribution from a bimodal distribution to a substantially monomodal distribution. The object 212 can be manufactured. In such embodiment 210, the AOM precursor material 214 must contain sufficient moisture to allow the treated AOM composition 212 to be made. In general, an AOM precursor material 214 has been found to contain a weight percent residual moisture concentration corresponding to a loss on drying (LOD) of at least about 0.10% by weight, and more preferably in the range of from about 0.10% by weight to about 0.2% by weight. Sufficient to produce a treated AOM composition 212 having a desired monomodal particle size distribution.

By placing an amount of AOM precursor material 214 (i.e., having a sufficient degree of residual moisture when measured by weight % LOI (dry weight loss)), it is placed in a container 235 and sealed to seal the container 235 to be airtight. The state can be made into a treated AOM composition 212. The sealed container 235 is then heated in step 253 to a temperature in the range of at least about 30 ° C, and preferably in the range of from 30 ° C to about 50 ° C, for a period of time sufficient to produce a treated AOM composition 212 having a desired monomodal particle size distribution. time. In general, heating 253 for at least about 7 days, and more preferably about 7-10 days, will suffice for this purpose.

Obviously, we have found that residual moisture in the AOM precursor material 214 can be recovered during the process, thus allowing for adequate "fresh" moisture during processing, ie, the most recent thermal decomposition of the AOM. Material 214 (ie, having a low moisture content). In other words, the moisture adsorbed into the smaller particles during capillary condensation tends to be released after the coalescence process, thus allowing the available water to be used for additional capillary agglomeration of other particle sites. For example, after sealing within the container 235, most of the AOM precursor material 214 will contain sufficient residual moisture to increase the relative humidity within the sealed container 235 to a range of 80-100%, which is sufficient to cause at a reasonable time (eg, The treated AOM composition 212 is produced within 7-10 days.

Method 210 can optionally involve additional processing steps. For example, the treated AOM powder product 212 can be subjected to an additional grinding or grinding step 256 to break up any bulk agglomerates that may form during the processing.

The treated AOM compositions, for example, 12, 112, 212, can advantageously be used to make AOM-based optical marking inks and polymer compositions. In a specific embodiment, the processed AOM compositions 12, 112, 212 can be used to replace some or all of the desired AOMs by special formulation to achieve one or more of the performance improvements and benefits described herein. .

Instance

Various example compositions of the treated alpha-AOM product 12 in accordance with the teachings provided herein are disclosed by three different processing methods 10, herein referred to as "fluidized bed steaming", "rotary dryer steaming". It is manufactured by "solvent spray method". In a fluidized bed steaming process, a thin layer or layer of a-AOM precursor material is placed in a shallow container or "boat" and then placed at 100% relative humidity as further detailed below. Inside the oven at 100 ° C. The processed by the rotary dryer steaming method is obtained by placing the α-AOM precursor material 14 into a rotary dryer or drum 34 in which a steam port 32 is provided. AOM composition 12. Finally, the treated AOM composition 12 produced by the solvent spray method is obtained by contacting the α-AOM precursor material 14 with a spray of atomized water 25 in the rotating drum 34. The following provides additional details regarding specific processing parameters, precursor materials, and processed products for various processing methods.

Fluidized bed steaming

Five individual tests, referred to herein as Tests 1-5, were performed to prepare treated alpha-AOM composition 12 from two different types of alpha-AOM precursor powder materials 14. In the first four tests (i.e., tests 1-4), commercially available or "standard" alpha-AOM precursor materials 14 were used. The standard alpha-AOM precursor material 14 exhibits a bimodal particle size distribution 16 (Fig. 2) that is generally used as such material 14. The standard alpha-AOM precursor material 14 was treated partially (in trials 1 and 2) or completely (in trials 3 and 4) to produce a corresponding partially- or fully processed alpha-AOM composition. Test 5 relates to the treatment of "ultrafinely ground" alpha-AOM precursor material 14. The ultrafine ground precursor material is additionally ground in a hammer mill to produce a precursor material 14 having a near monomodal particle size distribution, as seen in Figure 6.

Table I provides certain characteristics of two different types of a-AOM precursor powder materials 14 (i.e., standard and ultrafine grinding). Particle characteristics were obtained by mixing a small amount of a sample of each of the respective α-AOM precursor materials with isopropyl alcohol and analyzing the mixture in a Cilas laser particle size analyzer. The Cilas particle size analyzer can also generate the corresponding particle size distribution histogram and the cumulative distribution of the undersize and reproduce in Figure 2 (standard α-AOM precursor powder material) and Figure 6 (superfine grinding α-AOM) Precursor powder material).

All tests (i.e., Tests 1-5) were applied with steam and/or heat to two types of a-AOM precursor materials 14 (i.e., standard and ultrafine ground precursor materials) in the following methods to produce various tests. Composition. As indicated herein, Runs 1 and 2 involve partial processing of a standard alpha-AOM precursor material 14 to produce a partially processed alpha-AOM powder composition. Test 1 involves the treatment of the first part of the standard precursor material 14, whereas the test 2 involves the additional treatment of the composition of the test 1. Table II shows the particle size data for the compositions of Test 1 and Test 2. The particle size histograms of the compositions of Tests 1 and 2 were separately reproduced in Figures 7 and 8, and illustrate the gradual progression of the powder from bimodal particle size distribution to monomodal particle size distribution.

Run 3 involved complete treatment of the standard alpha-AOM precursor material 14 to produce a fully processed alpha-AOM composition 12. The particle size data of the fully treated alpha-AOM composition of Run 3 is also shown in Table II. The particle size histogram of the composition of Test 3 is reproduced in Figure 9.

Test 4 also involved the complete treatment of the standard alpha-AOM precursor material 14, but compared to the smaller sample size of test 1-3 (50 g precursor material 14) A large sample size (1 kg of precursor material 14) is involved. The particle size data and histograms of the three individual samples of Test 4 after complete treatment of the AOM composition are shown in Table III and Figures 3, 10(a) and 10(b), respectively.

Run 5 involved the complete treatment of 100 g of ultrafine ground alpha-AOM precursor material 14. Run 5 The particle size data and histograms for the three individual samples of the fully treated AOM composition are shown in Table IV and Figure 11 (a-c).

Trials 1 and 2:

As described, Runs 1 and 2 involved a partial treatment of 50 g of the standard a-AOM precursor powder material 14. The standard alpha-AOM precursor material 14 comprises a commercially available thermally reduced or "dried" alpha-AOM powder material commercially available from the Climax Molybdenum Company of Fort Madison, USA as described herein. A 50 g sample of the standard alpha-AOM precursor material 14 was dispersed into a thin layer or layer in a shallow open container and placed in a 100 ° C oven having a vessel containing boiling water therein. The boiling water in the oven is used to maintain a relative humidity of about 100% during processing. The precursor material 14 is heated and steam is applied in the process for about 6 hours to produce a partially treated AOM powder composition. The partially treated AOM powder composition of Test 1 was then removed from the oven and allowed to cool and dry for about 1 hour at room temperature. A small sample of the composition of Test 1 was then mixed with isopropyl alcohol and analyzed in a Cilas laser particle size analyzer as described herein.

Run 2 is a continuous test of Test 1 and involves placing the Test 1 composition back into the oven and subjecting the composition to additional heating at 100 ° C and 100% relative humidity. The test 2 composition was heated and an additional 8 hours of steam was applied. The partially treated Test 2 composition was then removed from the oven and allowed to cool and dry for about 1 hour at room temperature. a small portion of the test 2 composition then It was mixed with isopropyl alcohol and analyzed in a Cilas laser particle size analyzer.

The particle size data of the compositions of Tests 1 and 2 are shown in Table II. The particle size histograms of the powder compositions of Tests 1 and 2 were separately reproduced in Figures 7 and 8. And explain the gradual progress of the powder from bimodal particle size distribution to monomodal particle size distribution. As can be seen from the histogram, partial processing of the AOM precursor material 14 results in a gradual decrease in the number of bimodal peaks as processing time increases. Note, however, that the additional mode peak of the Test 2 composition appeared at a particle size of about 0.3 μm. It has been considered that the appearance of this modal peak is caused by the ultrasonic wave breaker of the Cilas laser particle size analyzer breaking up the agglomerated particles.

Trial 3:

The procedure used in Run 3, except Test 3, involved a complete treatment of 1 kg of standard alpha-AOM precursor material 14, similar to Runs 1 and 2. The standard alpha-AOM precursor material 14 once again contains a commercially available thermally reduced or "dried" alpha-AOM powder material commercially available from Climax Molybdenum Company as described herein. The standard alpha-AOM precursor material 14 is dispersed into a thin layer or layer in a shallow open container and then placed in an oven at 100 ° C of 100% relative humidity for a period of about 70 hours. The fully treated AOM composition of Run 3 was then removed and allowed to cool and dry for about 2 hours at room temperature, but this cooling time was not critical.

A small sample of Test 3 composition was then mixed with isopropanol and analyzed in a Cilas laser particle size analyzer. The particle size data of the test 3 samples are also shown in Table II. The corresponding particle size histogram is shown in Fig. 9. The test 3 sample was a completely single peak with the exception that its modal peak was again about 0.3 μm. Again, the modal peak appearing at about 0.3 μm is considered to be due to the laser particle size. The result of the analyzer's ultrasonic breaker.

Test 4:

Test 4 involved the treatment of 1 kg of standard alpha-AOM precursor material 14. The standard alpha-AOM precursor material 14 once again contains a thermally reduced or "dried" alpha-AOM powder material manufactured by Climax Molybdenum. The AOM precursor material 14 was dispersed into a thin layer in a shallow open container and placed in a 100 ° C oven having a container containing boiling water therein. The AOM precursor material 14 is maintained at 100 ° C air at 100% relative humidity for a period of about 72 hours. The test 4 composition was then dried at a high temperature of 105 °C.

Three individual samples of the composition of Test 4 were then mixed with isopropanol and analyzed in a Cilas laser particle size analyzer. The particle size data of the three samples of the composition of Test 4 are shown in Table III. The particle size histograms of the three samples are reproduced in Figures 3, 10(a) and 10(b).

As can be seen from the histograms of the three samples, the composition of the test 4 is finished. Full single peaks, with mode peaks of various samples appearing in the particle size range from about 5 [mu]m to about 6 [mu]m. Note that the three samples of the composition of Test 4 have no histograms showing modal peaks with smaller particle sizes. It has been considered that the sample particles of the test 4 composition were not broken by ultrasonic vibration during the measurement.

Test 5:

Run 5 involved the treatment of about 100 g of "ultrafinely ground" alpha-AOM precursor material 14. The ultrafinely ground α-AOM precursor material 14 is produced by grinding a standard, thermally reduced or "dried" α-AOM powder material from Climax Molybdenum Co., Ltd. in a hammer mill until the particle size distribution is close to a single peak. to make. Please see Figure 6. The ultrafinely ground α-AOM precursor material 14 was dispersed into a thin layer in a shallow open container and placed in a 100 ° C oven equipped with a boiling water container. The ultrafine ground alpha-AOM precursor material 14 is maintained at 100 ° C air at 100% relative humidity for a period of about 72 hours. The test 5 composition was then dried at a high temperature of 105 °C. Test 5 compositions of three individual samples and then with isopropyl Alcohol mixing and analysis was performed in a Cilas laser particle size analyzer. The particle size data of the three samples of the composition of Test 5 are shown in Table IV. The particle size histograms of the three samples were reproduced in Figure 11 (a-c).

The composition of Test 5 was a completely single peak, and the mode peaks of various samples appeared at a particle size of about 10 μm. As in the case of the composition of Test 4, the histograms of the three samples of the Test 5 composition also did not exhibit modal peaks of smaller particle size. It has been considered that the sample particles of the test 5 composition were not broken by ultrasonic vibration during the measurement.

Rotary dryer steaming

The rotary dryer steaming process involves placing a large amount of AOM precursor powder material 14 into a drum cylinder 34 and then applying steam to the precursor material 14 during rolling. The resulting wet intermediate powder product 24 is then removed from the drum 34 and allowed to dry. The sample does not require heating during or after the steaming process.

This particular embodiment involves treating about 2 kg of standard AOM precursor powder Body material 14. The standard alpha-AOM precursor material 14 once again contains a thermally reduced or "dried" alpha-AOM powder material manufactured by Climax Molybdenum. The particle size data and histogram of the α-AOM precursor material are shown in Table V and Figure 12, respectively. Note that the rotary dryer steaming process produces particle size data and histograms by a Microtrac particle size analyzer as shown herein. The AOM precursor material 14 is then placed into the drum 34 and steam is applied. The wet intermediate powder 24 is removed from the drum 34 after rolling and steaming.

A rotary dryer was used to steam the composition sample and then mixed with isopropanol and analyzed in a Microtrac laser particle size analyzer. The particle size data of the sample composition is shown in Table V. The particle size histogram of the sample is reproduced in Figure 13.

As can be seen from the histogram of the sample, the steam dryer composition of the rotary dryer is mainly a single peak, and its mode peak appears at a particle diameter of about 10 μm. Note that the histogram of the rotary dryer steaming composition exhibits a small mode peak at about 0.2 [mu]m. Once again, it is believed that the appearance of this modal peak is caused by the ultrasonic wave breaker of the Microtrac laser particle size analyzer breaking up the agglomerated particles.

Solvent spray method

The solvent spray method involves placing a large amount of AOM precursor powder material 14 into a drum cylinder 34 and then applying atomized water spray to the precursor material 14 during rolling. The wet intermediate powder product 24 is then removed from the drum 34 and allowed to dry. The sample did not require heating during or after the solvent spray method.

Four individual tests (Runs 1-4) for preparing the treated α-AOM composition 12 from the pretreated α-AOM precursor powder material were performed. The pretreated α-AOM powder material was produced from a standard α-AOM precursor material to which a quantity of water of 0.14% by weight was added. The particle size data of the pretreated precursor material are shown in Table VI. The particle size histogram of the pretreated material was reproduced in Figure 14. Particle size data and histograms for materials used in solvent spray methods were generated by a Microtrac laser particle size analyzer.

As can be seen from Fig. 14, the pretreated α-AOM material has a bimodal particle size distribution, and a small third mode peak appears at a particle diameter of about 0.3 μm, which is again considered to be due to the laser particle size. The analyzer's ultrasonic breaker broke the agglomerated particles.

Runs 1-4 relate to the manufacture of a treated alpha-AOM composition by the addition of varying amounts of water (i.e., atomized water spray) to the pretreated alpha-AOM material, as illustrated in Table VII. After the water is added, the formed wet intermediate powder 24 is removed from the drum 34.

A small sample of each of the four test compositions was then mixed with isopropanol and analyzed in a Microtrac laser particle size analyzer. The particle size data of the sample composition is shown in Table VII. The particle size histograms of the compositions of Tests 1-4 are reproduced in Figures 15-18, respectively, and the powder is distributed from bimodal particle size to The gradual progression of the unimodal particle size distribution. Note that the histogram of the composition prepared by the solvent spray method also exhibits a small mode peak at a small particle size of about 0.2 μm. Once again, it is believed that the appearance of these modal peaks is caused by the ultrasonic particle breaker of the laser particle size analyzer breaking up the agglomerated particles.

Intermediate adsorbent method

Another example is directed to method 110 in which solvent 122 is first applied to the intermediate adsorbent 123. The formed solvent-containing intermediate adsorbent 123 is then placed in a sealed container 135 along with the AOM precursor material 114. The AOM precursor material 114 again contains thermally reduced or "dried" alpha-AOM powder materials from Climax Molybdenum Company as described herein. The AOM material Feed 114 has a typical bimodal particle size distribution of other AOM precursor materials as described earlier. In this example, about 28 g of the silicone adsorbent 123 was added using deionized water. The silicone adsorbent 123 adsorbs about 30-35% by weight of deionized water, which is consistent with the theoretical value of the silicone at its temperature and 100% humidity. The formed solvent-containing silicone intermediate adsorbent 123 (accommodated in the venting bag 125) is then placed in a container 135 along with about 100 g of the AOM precursor material 114. The container 135 is then sealed (i.e., rendered substantially airtight) and maintained at room temperature (i.e., about 22 ° C) for about 120 hours (about 5 days).

Prior to the description, it must be noted that the amount of the silicone intermediate adsorbent 123 used in this example is much greater than the amount generally used to practice the particular embodiment. There are two reasons for this: First, to determine whether this method can cause the AOM precursor material 114 to produce a paste-like substance by supersaturation; secondly, to observe how much water the AOM needs to adsorb from the silicone intermediate adsorbent 123 is below optimum. Under conditions. The AOM precursor material 114 does not become a paste, even though the silicone intermediate adsorbent 123 contains more solvent 122 (i.e., water) than is required by the processing method. Subsequent analysis showed that the silicone intermediate adsorbent 123 released about 1/3 (i.e., 33%) of the adsorbed solvent 122, meaning that the overall treated AOM material 112 contained about 3-4% water by weight. On a large scale, the addition of the silicone intermediate adsorbent 123 in a sufficient amount to add about 0.3% by weight to about 0.5% by weight of water will give good results.

Continuing with the description, a small sample of the treated AOM material 112 is then mixed with isopropanol and analyzed in a Cilas particle size analyzer. The obtained particle size histogram is reproduced in Figure 21. As can be seen from the histogram, the processed AOM material 112 has a particle size distribution of about 7 A substantially single peak of the μm mode peak. Note that additional modal peaks appear at a particle size of about 0.2 μm. Again, it is believed that this modal peak is caused by the ultrasonic particle breaker of the laser particle size analyzer breaking up the agglomerated particles.

In summary, the claimed products and methods collectively represent a significant development in molybdenum ore technology. The above-mentioned treated AOM composition not only has a characteristic of a substantially monomodal particle size distribution, but can not be achieved by a conventional method, and can be manufactured with superiority as compared with a composition made of an untreated AOM composition. Performance and consistency of optical marking ink compositions. The treatment methods described herein can produce a large number of treated AOM compositions as well as having uniform particle size distribution characteristics.

Preferred embodiments of the invention have been described herein, and are intended to be modified as appropriate and still fall within the scope of the invention. The invention should therefore only be inferred from the following patentable scope:

10‧‧‧ method

12‧‧‧Processed AOM composition

14‧‧‧α-AOM precursor material

22‧‧‧Solvent

24‧‧‧ Wet intermediates

25‧‧‧Atomized water

26‧‧‧Atomizing nozzle

28‧‧‧Steam

30‧‧‧Steam generator equipment

32‧‧‧ steam outlet

34‧‧‧Rotating drum

40‧‧‧Roller

42‧‧‧Axis

44‧‧‧Drive motor

46‧‧‧Rotation direction

48‧‧‧Paddles

50‧‧‧ inner surface

52‧‧‧ heating device

54‧‧‧Dryer

56‧‧‧Additional grinding step

Claims (24)

A treatment method comprising: providing an initial supply of an ammonium octa molybdate precursor powder having a bimodal particle size distribution; applying a quantity of a solvent to the initial supply of the ammonium octamolybdate precursor powder to form a wet intermediate powder And allowing the wet intermediate powder to adsorb the applied solvent over a period of time, the amount of the applied solvent and the period of time sufficient to form a treated ammonium pentamolybdate powder having a substantially monomodal particle size distribution Things. The method of claim 1, wherein the applying a quantity of the solvent comprises applying water in an amount ranging from about 0.1% by weight to about 1% by weight based on the weight of the initial supply of the ammonium octamolybdate precursor powder. The initial supply of ammonium octa molybdate precursor powder. The method of claim 2, further comprising applying water in an amount of about 0.5% by weight to the initial supply of the ammonium octa molybdate precursor powder, based on the weight of the initial supply of the ammonium octamolybdate precursor powder. The method of claim 2, wherein the applying of the water comprises: atomizing the water to form an atomized stream; and directing the atomized stream of the water to the initial supply of the ammonium octamolybdate precursor powder. The method of claim 4, further comprising rolling the initial supply of the ammonium octa molybdate precursor powder upon directing the atomized stream of the water onto the initial supply of the ammonium octamolybdate precursor powder, such that substantially all The ammonium octamolybdate precursor powder The initial supply is exposed to the atomized stream of the water. The method of claim 5, further comprising heating the atomized stream that directs the water to the initial supply of the ammonium octamolybdate precursor powder. The method of claim 5, further comprising: suspending the atomized stream of the water; and heating the initial supply of the ammonium octa molybdate precursor powder after the suspension. The method of claim 7, further comprising repeating the suspending and the heating step alternately. The method of claim 1, wherein the initial supply of the ammonium octa molybdate precursor comprises the supply of an alpha-octamolybdate powder formed by thermal decomposition of ammonium dimolybdate. The method of claim 2, wherein the applying of the water comprises: providing a steam supply; and directing a vapor stream to the initial supply of the ammonium octamolybdate precursor powder. The method of claim 10, further comprising heating while directing the vapor stream to the initial supply of the ammonium octamolybdate precursor powder. The method of claim 10, further comprising: suspending the steam stream; and, after the discontinuation, heating the initial supply of the ammonium octamolybdate precursor powder. The method of claim 12, further comprising alternately repeating the suspending and the heating step until the treated octaammonium molybdate powder composition obtains a monomodal particle size distribution. The method of claim 1, wherein the treated ammonium octamolybate powder composition comprises an anhydrous loss on ignition value ranging from about 8 to about 8.8%. The method of claim 1, wherein the treated ammonium octamolybdate powder composition has a modal diameter ranging from about 4 μm to about 12 μm. The method of claim 1, wherein the treated ammonium octamolybdate powder composition has a modal particle size ranging from about 5 μm to about 7 μm. The method of claim 1, wherein the treated ammonium octamolybdate powder composition has a modal particle size of about 6 μm. The method of claim 1, wherein the treated ammonium octamolybdate powder composition has a modal particle size of about 10 μm. The method of claim 1, wherein the applying a quantity of the solvent comprises: providing an intermediate adsorbent; applying a quantity of the solvent to the intermediate adsorbent to produce a solvent-laden intermediate adsorbent; And the initial supply of the ammonium octamolybdate precursor powder into a container; and sealing the container; and wherein the allowing comprises: allowing the initial supply of the ammonium octa molybdate precursor powder to adsorb for a period of time The solvent desorbed from the intermediate adsorbent, the amount of the desorbed solvent and the period of time is sufficient to form a treated ammonium octa molybdate powder composition having a substantially monomodal particle size distribution. A method for producing a processed ammonium octamolybate powder composition, comprising: providing an initial supply of an α-octamolybdate precursor powder, the initial supply of the α-octamolybdate precursor powder having a bimodal particle size distribution ranging from a first mode peak of from about 1 [mu]m to about 4 [mu]m and a second mode peak ranging from about 6 [mu]m to about 10 [mu]m; applying a quantity of solvent to the initial alpha -octamolybdate powder Feeding; allowing the initial supply of the alpha-octamolybdate powder to adsorb the applied solvent over a period of time, the amount of solvent applied and the period of time being sufficient to form a treated ammonium pentamolybdate powder composition, The treated ammonium octamolybdate powder composition has a unimodal particle size distribution ranging from a mode peak of from about 6 μm to about 10 μm. A treated octaammonium molybdate powder composition by adding a content of water to an initial supply of an ammonium octa molybdate precursor powder having a bimodal particle size distribution, and by allowing the ammonium octamolybdate The powder initial feed adsorbs the added water for a period of time sufficient to produce a treated ammonium octa molybdate powder composition, the treated ammonium octa molybdate powder composition Has a single peak particle size distribution. The treated octaammonium molybdate powder composition of claim 21, comprising a modal peak ranging from about 4 [mu]m to about 12 [mu]m. An improved optically-labelable ink composition comprising an oxyanion of a polyvalent metal, a solvent, and a binder, wherein the improvement comprises utilizing a molybdenum having a substantially monomodal particle size distribution The ammonium acid powder is used as an oxygen ion of a polyvalent metal, and the ammonium octamolybdate powder system is initially supplied by applying a solvent to a mono-ammonium molybdate precursor powder to form a wet intermediate powder, and allowing the wet The intermediate powder adsorbs the applied solvent over a period of time sufficient to form a treated ammonium octamolybdate having a substantially monomodal particle size distribution. Powder composition. A treatment method comprising: providing an initial supply of an ammonium octa molybdate precursor powder having a bimodal particle size distribution and having a residual moisture of at least about 0.1 wt.% when measured by loss on drying; The initial powder supply is placed in a container; the container is sealed; and the sealed container is heated to a temperature of at least about 30 ° C for a period of time sufficient to form a treated octaammonium molybdate powder having a substantially monomodal particle size distribution. The time of the composition.