Dispersible activated bauxite particles and methods of forming dispersible activated bauxite particles

Abstract

Dispersible activated bauxite particles and methods of forming dispersible activated bauxite particles are disclosed, wherein bauxite is activated by a granulation process.

Description

[0001] Related Applications

[0002] This application claims the benefit of and priority to U.S. Provisional Patent Application No. 62 / 399,384, filed on August 19, 2022, entitled “Dispersible Activated Bauxite Granules and Methods for Forming Dispersible Activated Bauxite Granules,” which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates to dispersible activated bauxite particles and methods of forming dispersible activated bauxite particles. In particular, the present invention relates to dispersible activated bauxite particles and methods of forming dispersible activated bauxite particles, wherein the bauxite is activated by a granulation process. Background Art

[0004] Although alumina materials can be produced from a variety of raw materials, alumina materials are most commonly obtained from bauxite for commercial scale production. Alumina materials produced from bauxite can be manufactured by a variety of methods, but almost all methods involve some form of calcination and / or chemical activation, especially on a commercial scale. In conventional processes, bauxite is usually dried to a desired moisture content and crushed or ground to a desired size. The fine bauxite powder is then modified by the Bayer process, including heating under pressure between 150-200°C in caustic soda. The bauxite residue (also known as red mud, red sludge, bauxite tailings or alumina refinery residue) is removed by filtration, leaving sodium aluminate. The sodium aluminate is then treated with aluminum hydroxide and water, which promotes the removal of sodium hydroxide, and the resulting product is aluminum trihydrate. For commercial production, aluminum trihydrate is usually calcined at a specified temperature and duration to obtain suitable surface area and porosity characteristics for the desired application. The calcination process promotes the discharge of crystal water and causes atomic rearrangement. Activated aluminas with the highest surface areas are generally obtained at calcination temperatures of 250-550°C.

[0005] In addition to the conventional calcination step, alumina trihydrate may undergo a degree of activation by acid treatment, including partial acid dissolution and subsequent precipitation, which results in a highly porous pseudo-boehmite structure. Although not often performed on a commercial scale, the acid treatment and calcination steps may be performed simultaneously, often with a synergistic activation effect (e.g., the acid treatment reduces the calcination temperature necessary to obtain the desired properties).

[0006] Bauxite that has not been converted to aluminum trihydrate can also be activated by temperature and pH treatment without Bayer purification. However, such activated bauxite contains significant amounts of many other components in addition to aluminum oxide / oxyhydroxide / hydrate materials. For this reason, most applications (e.g., catalysts and water treatment) choose activated alumina materials rather than activated bauxite, even though properly activated bauxite can achieve similar surface area and porosity characteristics with less energy input and reduced environmental waste.

[0007] It is well known that alumina-based materials can beneficially promote the adsorption of orthophosphate in agricultural soils, mitigating the effects of nutrient loss while still providing adequate crop fertility. Additional benefits were observed when the alumina-based materials were pre-treated with phosphoric acid. This treatment effectively resulted in the alumina surface being "loaded" with adsorbed orthophosphate, and the loaded material could serve as the sole source of added phosphate to the soil. This treatment essentially eliminates the need for alumina amendments to capture phosphate in the soil environment and can create greater buffering capacity in the soil.

[0008] In agricultural applications, soil conditioners and fertilizers are often derived from various ores that contain high concentrations of desirable mineral components. Because purification and filtration operations are not always performed to minimize production costs, agricultural standard practices have supported the inclusion of undesirable or inert ore components in plant fertility programs. As long as the inactive filler materials do not contain high levels of certain heavy metals or radioactive materials, these inactive materials are well tolerated by crop systems.

[0009] Many fertilizers are granulated to improve the ability to spread nutrients over a large area. The granulation process usually relies on agglomeration or accumulation to achieve size growth. In large-scale granulation production, drum granulators are most commonly used because they can be designed to handle both binder-based agglomeration and chemical reaction-based accumulation processes. Most commonly, as part of the production process, excess moisture in the granules is removed by rotary dryers.

[0010] Globally, 90% of phosphoric acid produced is used as fertilizer (38% diammonium phosphate ("DAP"), 29% monoammonium phosphate ("MAP"), 8% triple superphosphate ("TSP"), and 15% other fertilizers such as superphosphate ("SSP"). In the United States, MAP usage exceeds DAP and is growing in market share. Almost all phosphoric acid used in fertilizer applications is produced through a multi-step process that includes phosphate rock mining, beneficiation, and concentrated sulfuric acid treatment. After phosphoric acid of suitable purity is produced, it can undergo various other processing to produce liquid fertilizers, solid fertilizers, animal feed products, etc.

[0011] While the production process for each solid fertilizer type (e.g., MAP, DAP, granulated TSP, and granulated SSP) is different, there are also some process similarities. For example, for a phosphate ammoniation granulation plant (a plant that produces MAP and DAP), the only significant difference is the input ratio of ammonia to phosphoric acid. Other than that, all of the equipment and instrumentation used for MAP and DAP production can remain essentially the same in both processes. While manufacturing processes may also vary from region to region, the basic process is largely standardized throughout the industry. In fact, most ammoniation granulation plants in the United States use a specific type of rotary drum mixer developed and patented by the Tennessee Valley Authority ("TVA") that includes a pre-neutralization step or a cross-tube reactor. The basic rotary drum ammoniation granulator design has an open rotating barrel that contains a rolling bed of recirculated solids.

[0012] In the TVA phosphoric acid ammoniation granulation process, phosphoric acid is mixed with about 93% by weight sulfuric acid in an acid buffer tank (see Figure 1 ). The mixed acid is then fed into a brick-lined acid reactor where it is partially neutralized with liquid or gaseous anhydrous ammonia. About 70% by weight of all the ammonia is introduced into the reaction vessel, producing a slurry of ammonium phosphate and about 22% by weight of water, which is transported to a rotary drum ammonia granulator and distributed along the bed. The remaining about 30% by weight of ammonia is sprayed out from under the slurry. Agglomeration occurs in the drum and terminates in the dryer. The wet granules then pass through a rotary concurrent dryer and then reach ambient temperature in a cooler.

[0013] Ammoniated granulation can also be carried out with acids other than phosphoric acid, including sulfuric acid and nitric acid, to produce ammonium sulfate and ammonium nitrate, respectively.

[0014] In contrast, for granular TSP, most are produced by the Dorr-Oliver granulation process (see Figure 3), which involves feeding acid-controlled phosphoric acid and ground phosphate rock to a reactor, feeding the ground phosphate rock and phosphoric acid slurry to a granulator, and subsequently drying in a generally continuous manner. Granular SSP follows a similar process; however, the ground phosphate rock is reacted with sulfuric acid rather than phosphoric acid. Granular nitrophosphate fertilizers may follow a similar process; the ground phosphate rock is reacted with nitric acid rather than phosphoric acid. Summary of the invention

[0015] In an exemplary embodiment, the dispersible activated bauxite particle comprises at least one activated bauxite domain and at least one supplemental domain selected from the group consisting of at least one nutrient domain, at least one pesticide domain, at least one biological additive domain, at least one sorbent domain, and combinations thereof. The at least one bauxite domain and the at least one supplemental domain are present in the dispersible activated bauxite particle as distinct domains aggregated together.

[0016] In another exemplary embodiment, the dispersible activated bauxite particles include activated bauxite particles and a water-soluble binder that agglomerates a plurality of activated bauxite particles into the dispersible activated bauxite particles. The activated bauxite particles are not chemically modified with NaOH.

[0017] In another exemplary embodiment, a method of forming bonded dispersible activated bauxite particles includes placing at least one acid in an acid buffer tank 10, reacting the at least one acid with ammonia in a reaction vessel 20 to form at least one ammonium salt, introducing bauxite particles in the presence of the at least one ammonium salt, co-agglomerating the at least one ammonium salt and the bauxite particles in a rotary drum ammoniation granulator to form bonded dispersible particles, and drying the bonded dispersible particles. At least one of introducing the bauxite particles in the presence of the at least one ammonium salt and drying the bonded dispersible particles activates the bauxite particles to form bonded dispersible activated bauxite particles having a bonded dispersible activated bauxite particle crush strength of at least 5 lbf.

[0018] In another exemplary embodiment, a method of forming bonded dispersible activated bauxite particles includes mixing ground alkaline rock and at least one of phosphoric acid, sulfuric acid, or nitric acid in a reactor, reacting the ground alkaline rock with at least one of phosphoric acid, sulfuric acid, or nitric acid in the reactor to form at least one of superphosphate slurry or nitrophosphate slurry, introducing bauxite particles in the presence of at least one of superphosphate slurry or nitrophosphate slurry, co-agglomerating at least one of superphosphate slurry or nitrophosphate slurry and the bauxite particles in a drum granulator to form bonded dispersible particles, and drying the bonded dispersible particles. Introducing at least one of the bauxite particles and drying the bonded dispersible particles in the presence of at least one of superphosphate slurry or nitrophosphate slurry activates the bauxite particles to form bonded dispersible activated bauxite particles having a bonded dispersible activated bauxite particle crush strength of at least 5 lbf.

[0019] In another exemplary embodiment, a method of forming bonded dispersible activated bauxite particles includes placing at least one acid in a reactor, introducing bauxite particles in the presence of the at least one acid, co-agglomerating the at least one acid and the bauxite particles in a drum granulator to form bonded dispersible particles, and drying the bonded dispersible particles. At least one of introducing the bauxite particles in the presence of the at least one acid and drying the bonded dispersible particles activates the bauxite particles to form bonded dispersible activated bauxite particles having a bonded dispersible activated bauxite particle crush strength of at least 5 lbf.

[0020] In another exemplary embodiment, a method of forming coherent dispersible activated bauxite particles comprises melting at least one of an acidic borate, an acidic phosphate, an acidic sulfate, or an acidic nitrate from a solid form to a liquid form, introducing bauxite particles in the presence of at least one of the acidic borate, the acidic phosphate, the acidic sulfate, or the acidic nitrate, co-agglomerating at least one of the acidic borate, the acidic phosphate, the acidic sulfate, or the acidic nitrate with the bauxite particles in a drum granulator to form coherent dispersible particles, and drying the coherent dispersible particles. At least one of introducing the bauxite particles in the presence of at least one of the acidic borate, the acidic phosphate, the acidic sulfate, or the acidic nitrate and drying the coherent dispersible particles activates the bauxite particles, thereby forming coherent dispersible activated bauxite particles having a coherent dispersible activated bauxite particle crush strength of at least 5 lbf.

[0021] In another exemplary embodiment, a method of forming agglomerated dispersible activated bauxite particles includes physically mixing bauxite particles with supplemental particles selected from the group consisting of nutrient particles, pesticide particles, biological particles, sorbent particles, and combinations thereof, agglomerating the bauxite particles with the supplemental particles and at least one water-soluble binder to form agglomerated dispersible particles, and drying the agglomerated dispersible particles at a temperature of at least 250°F to form agglomerated dispersible activated bauxite particles.

[0022] Other aspects of the disclosed subject matter are provided by:

[0023] A dispersible activated bauxite particle comprising at least one activated bauxite domain and at least one supplemental domain selected from the group consisting of at least one nutrient domain, at least one pesticide domain, at least one biological additive domain, at least one sorbent domain, and combinations thereof, wherein the at least one bauxite domain and the at least one supplemental domain are present in the dispersible activated bauxite particle as distinct domains aggregated together.

[0024] The dispersible activated bauxite particle of any preceding item, wherein the dispersible activated bauxite particle is a bonded dispersible activated bauxite particle, and at least one activated bauxite domain and at least one supplementary domain are present in the bonded dispersible activated bauxite particle as distinct domains bonded together, such that the bonded dispersible activated bauxite particle has a bonded dispersible bauxite particle crush strength of at least 5 lbf.

[0025] The dispersible activated bauxite particles of any preceding item, wherein the dispersible activated bauxite particles are agglomerated dispersible activated bauxite particles.

[0026] The dispersible activated bauxite particle of any preceding item, wherein the at least one supplementation domain comprises at least one nutrient domain, and the at least one nutrient domain comprises at least one additive selected from the group consisting of bioavailable substances of phosphorus, molybdenum, selenium, zinc, copper, cobalt, iron, nickel, manganese, vanadium, calcium, potassium, sulfur, chlorine, silicon, magnesium, sodium, nitrogen, boron and combinations thereof.

[0027] The dispersible activated bauxite particle of any preceding item, wherein said at least one nutrient domain comprises at least one phosphate domain as the bioavailable source of phosphorus.

[0028] Any of the preceding dispersible activated bauxite particles, wherein the at least one phosphate domain is selected from the group consisting of diammonium phosphate, monoammonium phosphate, triple superphosphate, superphosphate, nitrophosphate, and combinations thereof.

[0029] The dispersible activated bauxite particle of any preceding item, wherein at least one supplemental domain comprises at least one biological domain, and the at least one biological domain comprises at least one additive selected from the group consisting of humic substances, fulvic acid, live microorganisms, microbial metabolites, plant extracts, exogenous plant hormones, and combinations thereof.

[0030] The dispersible activated bauxite particle of any preceding item, wherein at least one supplemental domain comprises at least one pesticide domain, and the at least one pesticide domain comprises at least one additive selected from the group consisting of herbicides, insecticides, fungicides, nematicides and combinations thereof.

[0031] The dispersible activated bauxite particle of any preceding item, wherein at least one supplemental domain comprises at least one adsorbent domain, and the at least one adsorbent domain comprises at least one additive selected from the group consisting of zeolites, zeolite-types, and combinations thereof.

[0032] The dispersible activated bauxite particle of any preceding item, wherein the at least one supplemental domain comprises at least one phosphate domain and at least one of: an additional nutrient domain other than phosphate, at least one pesticide domain, at least one biological additive domain, and combinations thereof.

[0033] The dispersible activated bauxite particle of any preceding item, wherein the at least one activated bauxite domain and the at least one supplementary domain are uniformly distributed within the particle in the dispersible activated bauxite particle.

[0034] The dispersible activated bauxite particle of any preceding item, wherein the at least one activated bauxite domain and the at least one supplementary domain are uniformly distributed in the dispersible activated bauxite particle.

[0035] Any dispersible activated bauxite particle of the preceding items having an activated bauxite domain:supplementary domain weight ratio of 5:1 to 1:5.

[0036] The dispersible activated bauxite particles of any preceding item further comprising at least one of a water-soluble binder, a suspending agent or an emulsifier.

[0037] The dispersible activated bauxite particle of any preceding item, further comprising at least one additional domain as a different domain, wherein the at least one additional domain is selected from the group consisting of at least one nutrient domain, at least one pesticide domain, at least one biological additive domain, at least one adsorbent domain, and combinations thereof.

[0038] The dispersible activated bauxite particle of any preceding item, wherein the at least one additional domain is coherently agglomerated with the at least one activated bauxite domain and the at least one supplementary domain in the dispersible activated bauxite particle.

[0039] The dispersible activated bauxite particle of any preceding item, wherein the at least one additional domain is agglomerated with at least one activated bauxite domain and at least one supplementary domain in the dispersible activated bauxite particle.

[0040] The dispersible activated bauxite particle of any preceding item, wherein the at least one additional domain is coated onto at least one bauxite domain and at least one supplementary domain that are aggregated together.

[0041] The dispersible activated bauxite particle of any preceding item, wherein the at least one activated bauxite domain has an alumina content of at least 35 wt% based on the total weight of the at least one activated bauxite domain.

[0042] The dispersible activated bauxite particle of any preceding item, wherein the at least one activated bauxite domain has a total content of aluminum oxide and iron oxide of at least 55 wt% based on the total weight of the at least one activated bauxite domain.

[0043] The dispersible activated bauxite particle of any preceding item, wherein the at least one activated bauxite domain comprises activated mineral bauxite that has not been chemically modified with NaOH.

[0044] The dispersible activated bauxite particle of any preceding item, wherein the at least one activated bauxite domain comprises at least one of activated laterite-type bauxite or activated karst-type bauxite.

[0045] The dispersible activated bauxite particles of any preceding item, comprising activated bauxite particles and a water-soluble binder, wherein the water-soluble binder agglomerates a plurality of activated bauxite particles into dispersible activated bauxite particles, wherein the activated bauxite particles are not chemically modified with NaOH.

[0046] The dispersible activated bauxite particles of any preceding item, wherein the dispersible activated bauxite particles are provided as a coating on a seed.

[0047] The dispersible activated bauxite particle of any preceding item, wherein the activated bauxite particle has an alumina content of at least 35 wt % based on the total weight of the activated bauxite particle.

[0048] The dispersible activated bauxite particle of any preceding item, wherein the activated bauxite particle has a total content of aluminum oxide and iron oxide of at least 55 wt % based on the total weight of the activated bauxite particle.

[0049] The dispersible activated bauxite particles of any preceding item, wherein the activated bauxite particles comprise at least one of activated laterite-type bauxite or activated karst-type bauxite.

[0050] Any of the preceding dispersible activated bauxite particles, further comprising at least one of a suspending agent or an emulsifier.

[0051] Any of the preceding dispersible activated bauxite particles, wherein the dispersible activated bauxite particles have a moisture content of less than 10% by weight.

[0052] The dispersible activated bauxite particles of any preceding item, wherein the dispersible activated bauxite particles have a size of less than 0.6 mm.

[0053] A method of forming bonded dispersible activated bauxite particles comprising placing at least one acid in an acid buffer tank, reacting the at least one acid with ammonia in a reaction vessel to form at least one ammonium salt, introducing bauxite particles in the presence of the at least one ammonium salt, co-agglomerating at least one of the ammonium salt and the bauxite particles in a rotary drum ammoniation granulator to form bonded dispersible particles, and drying the bonded dispersible particles, wherein at least one of introducing the bauxite particles in the presence of the at least one ammonium salt and drying the bonded dispersible particles activates the bauxite particles to form bonded dispersible activated bauxite particles having a bonded dispersible activated bauxite particle crush strength of at least 5 lbf.

[0054] The method of any preceding item, wherein the at least one acid is selected from the group consisting of boric acid, phosphoric acid, sulfuric acid, nitric acid and combinations thereof, and the at least one ammonium salt is selected from the group consisting of ammonium pentaborate, ammonium phosphate, ammonium sulfate, ammonium nitrate and combinations thereof.

[0055] The method of any preceding item, wherein introducing the bauxite particles in the presence of the at least one ammonium salt comprises premixing the bauxite particles with the at least one acid prior to reacting the at least one acid with the ammonia.

[0056] The method of any preceding item, wherein introducing the bauxite particles in the presence of at least an ammonium salt comprises adding the bauxite particles to at least one of an acid buffer tank, a reaction vessel, or a rotary drum ammoniation granulator.

[0057] The method of any preceding item, wherein the reaction vessel is a cross-tube reactor.

[0058] The method of any preceding item, wherein introducing the bauxite pellets in the presence of at least one ammonium salt comprises feeding the bauxite pellets through a cross-tube reactor.

[0059] The method of any preceding item, wherein drying the bound dispersible granules comprises drying the bound dispersible granules in a rotary dryer.

[0060] Any preceding method, further comprising introducing the bauxite particles into a rotary dryer.

[0061] A method of forming bonded dispersible activated bauxite particles comprising placing at least one acid in an acid buffer tank, reacting the at least one acid with ammonia in a reaction vessel to form at least one ammonium salt, introducing bauxite particles in the presence of the at least one ammonium salt, co-agglomerating at least one of the ammonium salt and the bauxite particles in a rotary drum ammoniation granulator to form bonded dispersible particles, and drying the bonded dispersible particles, wherein at least one of introducing the bauxite particles in the presence of the at least one ammonium salt and drying the bonded dispersible particles activates the bauxite particles to form bonded dispersible activated bauxite particles having a bonded dispersible activated bauxite particle crush strength of at least 5 lbf.

[0062] A method as in any preceding item, wherein the ground alkaline rock is ground phosphate rock.

[0063] The method of any preceding item, wherein introducing the bauxite particles in the presence of at least one of a superphosphate slurry or a nitrophosphate slurry comprises premixing the bauxite particles with at least one of phosphoric acid, sulfuric acid or nitric acid prior to mixing the at least one of phosphoric acid, sulfuric acid or nitric acid with the ground phosphate rock.

[0064] The method of any of the preceding items, wherein introducing the bauxite pellets in the presence of at least one of a superphosphate slurry or a nitrophosphate slurry comprises adding the bauxite pellets to at least one of an acid control tank upstream of the reactor, a basic rock weigh feeder upstream of the reactor, the reactor, or a drum granulator.

[0065] The method of any preceding item, wherein drying the bound dispersible granules comprises drying the bound dispersible granules in a rotary dryer.

[0066] Any preceding method, further comprising introducing the bauxite particles into a rotary dryer.

[0067] A method of forming bonded dispersible activated bauxite particles comprising placing at least one acid in a reactor, introducing bauxite particles in the presence of the at least one acid, co-agglomerating the at least one acid and the bauxite particles in a drum granulator to form bonded dispersible particles, and drying the bonded dispersible particles, wherein at least one of introducing the bauxite particles in the presence of the at least one acid and drying the bonded dispersible particles activates the bauxite particles to form bonded dispersible activated bauxite particles having a bonded dispersible activated bauxite particle crush strength of at least 5 lbf.

[0068] The method of any preceding item, wherein the at least one acid is selected from the group consisting of boric acid, phosphoric acid, sulfuric acid, nitric acid, and combinations thereof.

[0069] The method of any preceding item, wherein drying the bound dispersible granules comprises drying the bound dispersible granules in a rotary dryer.

[0070] Any of the preceding methods, further comprising introducing the bauxite particles into a rotary dryer.

[0071] A method of forming bonded dispersible activated bauxite particles comprising melting at least one of an acidic borate, an acidic phosphate, an acidic sulfate, or an acidic nitrate from a solid form to a liquid form, introducing bauxite particles in the presence of at least one of the acidic borate, the acidic phosphate, the acidic sulfate, or the acidic nitrate, co-agglomerating at least one of the acidic borate, the acidic phosphate, the acidic sulfate, or the acidic nitrate with the bauxite particles in a drum granulator to form bonded dispersible particles, and drying the bonded dispersible particles, wherein at least one of introducing the bauxite particles in the presence of at least one of the acidic borate, the acidic phosphate, the acidic sulfate, or the acidic nitrate and drying the bonded dispersible particles activates the bauxite particles to form bonded dispersible activated bauxite particles having a bonded dispersible activated bauxite particle crush strength of at least 5 lbf.

[0072] The method of any preceding item, wherein the acidic phosphate is selected from the group consisting of monoammonium phosphate, diammonium phosphate, and combinations thereof.

[0073] The method of any preceding item, wherein melting at least one of an acidic borate, an acidic phosphate, an acidic sulfate, or an acidic nitrate comprises and co-agglomerating at least one of an acidic borate, an acidic phosphate, an acidic sulfate, or an acidic nitrate and the bauxite particles comprises a steam granulation process.

[0074] A method of forming agglomerated dispersible activated bauxite particles comprises physically mixing bauxite particles with supplemental particles selected from the group consisting of nutrient particles, pesticide particles, bioparticles, adsorbent particles, and combinations thereof, agglomerating the bauxite particles with the supplemental particles and at least one water-soluble binder to form agglomerated dispersible particles, and drying the agglomerated dispersible particles at a temperature of at least 250°F to form agglomerated dispersible activated bauxite particles.

[0075] The method of any of the preceding items, wherein the nutrient particles include ingredients selected from the group consisting of: bioavailable substances of phosphorus, molybdenum, selenium, zinc, copper, cobalt, iron, nickel, manganese, vanadium, calcium, potassium, sulfur, chlorine, silicon, magnesium, sodium, nitrogen, boron, and combinations thereof.

[0076] Any of the preceding methods, wherein the nutrient particles include phosphate as the bioavailable source of phosphorus.

[0077] The method of any preceding item, wherein the phosphate is selected from the group consisting of diammonium phosphate, monoammonium phosphate, triple superphosphate, superphosphate, nitrified phosphates and combinations thereof.

[0078] The method of any preceding item, wherein the bioparticles include a component selected from the group consisting of humus, fulvic acid, live microorganisms, microbial metabolites, plant extracts, exogenous plant hormones, and combinations thereof.

[0079] The method of any preceding item, wherein the pesticide granules include an ingredient selected from the group consisting of herbicides, insecticides, fungicides, nematicides, and combinations thereof.

[0080] Any of the preceding methods, wherein the adsorbent particles include a component selected from the group consisting of zeolites, zeolite-types, and combinations thereof. BRIEF DESCRIPTION OF THE DRAWINGS

[0081] These and other features, aspects and advantages of the present subject matter will become better understood when the following detailed description is read with reference to the accompanying drawings, in which:

[0082] Figure 1 is a schematic diagram of the known and currently used production of MAP and DAP from phosphoric acid when a pre-neutralization step is used.

[0083] Figure 2 is a schematic diagram of the production of bonded dispersible activated bauxite particles according to an embodiment of the present disclosure.

[0084] Figure 3 is a schematic diagram for producing granular TSP and granular SSP from at least one of phosphoric acid or sulfuric acid and phosphate rock as is known and currently used. The schematic diagram for the production of nitrophosphate is the same except that nitric acid is used instead of sulfuric acid or phosphoric acid. The schematic diagram for the production of ammonium pentaborate is the same except that boric acid is used instead of sulfuric acid or phosphoric acid.

[0085] Figure 4 is a schematic diagram of the production of bonded dispersible activated bauxite particles according to an embodiment of the present disclosure.

[0086] Figure 5 is a schematic cross-sectional view of a dispersible activated bauxite particle according to an embodiment of the present disclosure.

[0087] Figure 6 is the available P according to the comparative prediction of the embodiments of the present disclosure 2 O 5 Compared with the experimentally determined P in the particles 2 O 5 .

[0088] Figure 7 is a thermogravimetric analysis of bauxite, ammonium phosphate particles embedded in bauxite, and produced monoammonium phosphate according to embodiments of the present disclosure.

[0089] Figure 8 is a comparison of the total nitrogen content of the particles measured according to an embodiment of the present disclosure and P2 O 5 Content diagram.

[0090] Fig. 9 is a graph comparing ammonia input reduction versus the content of activated bauxite in a particle according to an embodiment of the present disclosure.

[0091] Fig.10 is a graph comparing the reduction in nitrogen content of a particle versus the amount of activated bauxite in the particle, according to an embodiment of the present disclosure.

[0092] Fig.11 is a graph comparing the reduction in nitrogen content compared to the expected nitrogen content versus the activated bauxite content in a particle according to an embodiment of the present disclosure.

[0093] Fig.12 1 is a graph showing the effect of the calcination-based method on the P of bauxite (Bauxite #1) according to an embodiment of the present disclosure. 2 O 5 Fig. 4 shows the effect of adsorption on the

[0094] Fig.13 is a comparison of the embodiments according to the present disclosure 2 O 5 Plot of availability versus activated bauxite content in pellets.

[0095] Fig.14 is a comparison P according to one embodiment of the present disclosure 2 O 5 Plot of availability versus activated bauxite content in pellets.

[0096] Fig.15 is a graph of phosphate release from various particles over time according to embodiments of the present disclosure.

[0097] Fig.16 is a graph showing calculated crystal water loss during a granulation process according to an embodiment of the present disclosure.

[0098] Fig.17 is a graph showing the calculated loss on ignition of bauxite during pelletizing according to an embodiment of the present disclosure.

[0099] Fig.18 is a graph comparing the propensity of different bauxites to volatilize water of crystallization in their crystal lattices according to an embodiment of the present disclosure.

[0100] Fig.19 is a graph showing the relationship between activated bauxite content and reduction in ammonia input during pelletizing according to embodiments of the present disclosure.

[0101] Fig. 20is a graph comparing calculated ammonia reduction based on ammonia-phosphoric acid imbalance (determined by titrating the granules exiting the granulator) versus the activated bauxite content in the granules according to embodiments of the present disclosure.

[0102] Fig.21 is a graph comparing ammonia reduction of different bauxites and the content of activated bauxite according to an embodiment of the present disclosure.

[0103] Fig. 22 is a comparison of the water solubility, citrate solubleness and citrate insolubleness of the first bauxite according to an embodiment of the present disclosure 2 O 5 Plot of activated bauxite content.

[0104] Fig.23 is a comparison of the water solubility, citrate solubleness and citrate insolubleness of the second bauxite according to an embodiment of the present disclosure 2 O 5 Plot of activated bauxite content.

[0105] Fig.24 is a comparative third bauxite water solubility, citrate solubleness and citrate insolubleness according to an embodiment of the present disclosure 2 O 5 Plot of activated bauxite content.

[0106] Fig.25 is a graph of particles (by size) produced compared to raw bauxite inclusions according to embodiments of the present disclosure.

[0107] Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same features. DETAILED DESCRIPTION

[0108] Disclosed herein are dispersible activated bauxite particles and methods for forming dispersible activated bauxite particles, wherein the bauxite is activated by a granulation process. Although raw bauxite may be able to buffer phosphorus in a soil system in a manner similar to activated alumina, the orthophosphate "preload" capacity of raw bauxite is much lower than that of activated alumina. Therefore, in an orthophosphate preload system, activated alumina is superior to known bauxite amendments. However, under phosphate loading conditions, properly activated bauxite behaves more like activated alumina. Compared to particles and methods lacking one or more features disclosed herein, embodiments of the present disclosure have higher production efficiency, reduced cost, reduced inter-particle variability, increased phosphate absorption, less environmental impact, or a combination thereof.

[0109] As used herein, "about" means a deviation of up to 10% from the value so modified. All values ​​modified with "about" are also intended to convey the unmodified value as an alternative, thus, for example, "about 10 μm" discloses a range of 9-11 μm as well as specifically 10 μm.

[0110] As used herein, "bonded" dispersible particles are distinguished from "agglomerated" dispersible particles in that "agglomerated" refers to particles formed by mechanically agglomerating at least two types of pre-granulated particles together, while "bonded" refers to particles formed by agglomerating one type of pre-granulated particles with a second material domain formed simultaneously. The structural differences between bonded dispersible particles and agglomerated dispersible particles include, but are not limited to, greater particle crush strength, improved abrasion resistance, reduced moisture content, higher hygroscopic stability, less inter-particle variability in bauxite:supplement weight ratio, greater contact surface area between bauxite domain 2 and phosphate domain 3 resulting in tighter bonding, increased bauxite surface area, reduced binder incorporation, greater degree of mixed domains, or a combination thereof.

[0111] As used herein, "activated" refers to a material having reduced water of crystallization, increased surface area, and a crystalline phase with greater stability compared to the same material in an unactivated form.

[0112] In one embodiment, the method for forming the cohesive dispersible activated bauxite particles 1 comprises an ammoniating-granulation process with any suitable acid including but not limited to boric acid, phosphoric acid, sulfuric acid, nitric acid or a combination thereof, a granulation process with any suitable acid including but not limited to boric acid, phosphoric acid, sulfuric acid, nitric acid or a combination thereof, a granulation process with phosphoric acid, sulfuric acid, nitric acid or a combination thereof and ground alkaline rock, or a granulation process with liquid acidic borates, liquid acidic phosphates, liquid acidic sulfates, liquid acidic nitrates or a combination thereof melted from a solid state. In another embodiment, the method for forming agglomerated dispersible activated bauxite particles comprises physically mixing the bauxite particles with supplementary particles and at least one water-soluble binder, followed by drying at a temperature of at least 250°F.

[0113] refer to Figure 2In one embodiment, a method of forming coherent dispersible activated bauxite particles 1 includes placing at least one acid (e.g., but not limited to boric acid, phosphoric acid, sulfuric acid, nitric acid, or a combination thereof) in an acid buffer tank 10, reacting the at least one acid with ammonia in a reaction vessel 20 to form at least one ammonium salt (including but not limited to ammonium pentaborate, ammonium phosphate, ammonium sulfate, ammonium nitrate, or a combination thereof), introducing bauxite particles in the presence of the at least one ammonium salt, co-agglomerating the at least one ammonium salt and the bauxite particles in a rotary drum ammoniation-granulator 30 to form coherent dispersible particles, and drying the coherent dispersible particles. At least one of introducing the bauxite particles in the presence of the at least one ammonium salt and drying the coherent dispersible particles activates the bauxite particles to form coherent dispersible activated bauxite particles having a coherent dispersible activated bauxite particle crush strength of at least 5 lbf. The at least one activated bauxite domain 2 and the at least one phosphate, sulfate, or nitrate domain 3 are present in the coherent dispersible activated bauxite particles 1 as distinct domains cohesively agglomerated together.

[0114] Introducing the bauxite pellets in the presence of at least one ammonium salt may include premixing the bauxite pellets with the at least one acid prior to reacting the at least one acid with ammonia. Introducing the bauxite pellets in the presence of at least one ammonium salt may include adding the bauxite pellets to at least one of the acid buffer tank 10, the reaction vessel 20, or the rotary drum amination granulator 30.

[0115] The reaction vessel 20 may be a cross-tube reactor. In one embodiment, introducing the bauxite pellets in the presence of at least one ammonium salt comprises feeding the bauxite pellets through a cross-tube reactor.

[0116] Drying the bonded dispersible particles 1 may include drying the bonded dispersible particles 10 in a rotary dryer 40. In one embodiment, the bauxite particles may be introduced into the rotary dryer 40. Optionally, the bonded dispersible particles 1 may be introduced into a rotary cooler 50 after the rotary dryer 40.

[0117] refer to Figure 4In one embodiment, a method of forming bonded dispersible activated bauxite particles 1 includes mixing at least one of phosphoric acid, sulfuric acid or nitric acid and ground alkaline rock in a reactor 20, feeding the slurry into a granulator 30, introducing the bauxite particles in the presence of agglomerated superphosphate or nitrated phosphate, co-agglomerating the superphosphate or nitrated phosphate and the bauxite particles in the granulator 30 to form bonded dispersible particles 1, and drying the bonded dispersible particles 1, wherein introducing the bauxite particles in the presence of at least one of the superphosphate slurry or the nitrated phosphate slurry and at least one of the drying the bonded dispersible particles 1 activates the bauxite particles to form bonded dispersible activated bauxite particles 1 having a bonded dispersible activated bauxite particle crush strength of at least 5 lbf. The at least one bauxite domain 2 and the at least one phosphate, sulfate or nitrate domain 3 are present in the bonded dispersible activated bauxite particles 1 as distinct domains cohesively agglomerated together. The ground alkaline rock may be ground phosphate rock.

[0118] Introducing the bauxite pellets in the presence of at least one of a superphosphate slurry or a nitrophosphate slurry may include premixing the bauxite pellets with at least one of phosphoric acid, sulfuric acid, or nitric acid prior to mixing the at least one of phosphoric acid, sulfuric acid, or nitric acid with the ground alkaline rock. Introducing the bauxite pellets in the presence of at least one of a superphosphate slurry or a nitrophosphate slurry may include adding the bauxite pellets to at least one of an acid control tank upstream of the reactor, a basic rock weigh feeder upstream of the reactor, the reactor, or a drum granulator 30.

[0119] Drying the bound dispersible granules 1 may include drying the bound dispersible granules 10 in a rotary dryer 40. In one embodiment, the bauxite particles may be introduced into the rotary dryer 40.

[0120] In another embodiment, a method of forming coherent dispersible activated bauxite particles 1 includes placing at least one acid (such as but not limited to boric acid, phosphoric acid, sulfuric acid, nitric acid, or a combination thereof) in a reactor, introducing bauxite particles in the presence of the at least one acid, co-agglomerating the at least one acid and the bauxite particles in a drum granulator 30 to form coherent dispersible particles, and drying the coherent dispersible particles. At least one of introducing the bauxite particles in the presence of the at least one acid and drying the coherent dispersible particles 1 activates the bauxite particles to form coherent dispersible activated bauxite particles 1 having a coherent dispersible activated bauxite particle crush strength of at least 5 lbf. The at least one bauxite domain 2 and the at least one phosphate domain 3 are present in the coherent dispersible activated bauxite particles 1 as distinct domains cohesively agglomerated together.

[0121] Drying the bound dispersible granules 1 may include drying the bound dispersible granules 10 in a rotary dryer 40. In one embodiment, the bauxite particles may be introduced into the rotary dryer 40.

[0122] In another embodiment, a method of forming a coherent dispersible activated bauxite particle 1 comprises melting at least one of an acidic phosphate, an acidic sulfate, or an acidic nitrate from a solid form to a liquid form, introducing the bauxite particles in the presence of at least one of the acidic phosphate, acidic sulfate, or acidic nitrate, co-agglomerating the at least one of the acidic phosphate, acidic sulfate, or acidic nitrate with the bauxite particles in a drum granulator 30 to form coherent dispersible particles, and drying the coherent dispersible particles. At least one of introducing the bauxite particles in the presence of at least one of the acidic phosphate, acidic sulfate, or acidic nitrate and drying the coherent dispersible particles 1 activates the bauxite particles, thereby forming a coherent dispersible activated bauxite particle 1 having a coherent dispersible activated bauxite particle crush strength of at least 5 lbf. The at least one bauxite domain 2 and the at least one phosphate, sulfate, or nitrate domain 3 are present in the coherent dispersible activated bauxite particle 1 as distinct domains cohesively agglomerated together. The at least one acid phosphate, acid sulfate or acid nitrate may be, but is not limited to, monoammonium phosphate, diammonium phosphate or a combination thereof. Melting the at least one acid phosphate, acid sulfate or acid nitrate and co-agglomerating the at least one acid phosphate, acid sulfate or acid nitrate and the bauxite particles may include any suitable process, including but not limited to a steam granulation process.

[0123] The acid phosphate, acid sulfate, or acid nitrate may be any suitable material including, but not limited to, monoammonium phosphate, diammonium phosphate, or a combination thereof.

[0124] Melting the at least one of the acid phosphate, acid sulfate, or acid nitrate and co-agglomerating the at least one of the acid phosphate, acid sulfate, or acid nitrate and the bauxite particles may include a steam pelletizing process.

[0125] In another exemplary embodiment, the method of forming agglomerated dispersible activated bauxite particles 1 comprises physically mixing bauxite particles with supplemental particles selected from the group consisting of nutrient particles, pesticide particles, bioparticles, adsorbent particles, or combinations thereof, agglomerating the bauxite particles with the supplemental particles and at least one water-soluble binder to form agglomerated dispersible particles 1, and heating the agglomerated activated bauxite particles 1 at a temperature of at least 250°F, or at least 275°F, or at least 300°F, or at least 325°F, or at least 350°F, or at least 375°F, or at least 400°F, or at least 425°F, or at least 450°F, or at least or at least 725°F, or at least 750°F, or at least 775°F, or at least 800°F, or at least 825°F, or at least 850°F, or at least 875°F, or at least 900°F to form agglomerated dispersible activated bauxite particles.

[0126] The nutrient granules may include bioavailable materials of phosphorus, molybdenum, selenium, zinc, copper, cobalt, iron, nickel, manganese, vanadium, calcium, potassium, sulfur, chlorine, silicon, magnesium, sodium, nitrogen, boron or a combination thereof. The nutrient granules may include phosphate as a bioavailable material of phosphorus. The phosphate may be any suitable phosphate, including but not limited to diammonium phosphate, monoammonium phosphate, triple superphosphate, superphosphate, nitrated phosphate or a combination thereof.

[0127] The bioparticles may include humus, fulvic acid, live microorganisms, microbial metabolites, plant extracts, exogenous plant hormones, or combinations thereof.

[0128] The pesticide pellets may include herbicides, insecticides, fungicides, nematicides, or a combination thereof.

[0129] The sorbent particles may include zeolite, zeolite-type, or a combination thereof.

[0130] Referring to the foregoing method, introducing the bauxite particles may include premixing the bauxite particles with boric acid, phosphoric acid, sulfuric acid or nitric acid prior to introduction, adding the bauxite particles to an acid buffer tank 10, adding the bauxite particles to a reaction vessel 20, adding the bauxite particles to a rotary drum amination granulator 30, or any combination thereof. In one embodiment, the bauxite particles are maintained in a pH range of about 1.5 to about 7.5, or about 1.5 to 2.5, or about 2 to 3, or about 2.5 to 3.5, or about 3 to 4, or about 3.5 to 4.5, or about 4 to 5, or about 4.5 to 5.5, or about 5 to 6, or about 5.5 to 6.5, or about 6 to 7, or about 6.5 to 7.5, or any sub-range or combination thereof from introduction to bonding agglomeration or agglomeration. Drying the bonded dispersible bauxite particles 1 may include drying the dispersible bauxite particles 1 in a rotary dryer 40. Additional bauxite particles may be introduced into the rotary dryer 40 for drying and further agglomeration with the dispersible bauxite particles 1 .

[0131] The bonded dispersible activated bauxite particles 1 may have a greater bonded dispersible activated bauxite particle crush strength than the agglomerated dispersible activated bauxite particles 1 formed by agglomerating bauxite particles. In one embodiment, the bonded dispersible activated bauxite particles 1 have a bonded dispersible particle crush strength of at least 5 lbf, or at least 5.5 lbf, or at least 6 lbf, or at least 6.5 lbf, or at least 7.5 lbf, or at least 8 lbf, or at least 8.5 lbf, or at least 9 lbf, or at least 9.5 lbf, or at least 10 lbf.

[0132] The bonded dispersible activated bauxite particles 1 may have reduced inter-particle variability in bauxite:supplement weight ratio, or a 5% reduction, or a 10% reduction, or a 15% reduction, or a 20% reduction, or a 25% reduction in bauxite:supplement weight ratio compared to agglomerated dispersible activated bauxite particles formed by agglomerating bauxite particles with preformed supplement particles. In one embodiment, the bonded dispersible activated bauxite particles 1 have an inter-particle variability in bauxite:supplement weight ratio of ±40%, or ±35%, or ±30%, or ±25%, or ±20%, or ±15%. As used herein, inter-particle variability is measured relative to the smaller components of bauxite and supplementation, as measured by the average value of the entire bonded dispersible activated bauxite particle 1, such that if the average value of the bauxite:supplement weight ratio is 50:50 and the inter-particle variability is ±40%, the bauxite:phosphate weight ratio may be in the range of 30:70 to 70:30. As a further explanation, if the average value of the bauxite:supplement weight ratio is 25:75 and the inter-particle variability is ±40%, the bauxite:supplement weight ratio may be in the range of 15:85 to 35:65.

[0133] The structural differences between "bonded dispersible particles" and "agglomerated dispersible particles" include, but are not limited to, greater particle crush strength, improved abrasion resistance, reduced moisture content, higher hygroscopic stability, less inter-particle variability in bauxite:supplement weight ratio, greater contact surface area between bauxite and supplement domain 3, tighter bonding between bauxite domain 2 and supplement domain 3, increased bauxite surface area, reduced binder incorporation, a greater degree of mixed domains, or a combination thereof.

[0134] In one embodiment, the dispersible activated bauxite particle 1 comprises at least one activated bauxite domain 2 and at least one supplementary domain 3, wherein the at least one activated bauxite domain 2 and the at least one supplementary domain 3 are present in the dispersible activated bauxite particle 1 as distinct domains cohesively agglomerated together. The dispersible activated bauxite particle 1 may be a cohesive dispersible activated bauxite particle 1 or an agglomerated dispersible activated bauxite particle 1.

[0135] The at least one supplementation domain 3 may include at least one nutrient domain, at least one pesticide domain, at least one biological additive domain, at least one adsorbent domain, or a combination thereof.

[0136] Suitable at least one nutrient domain includes, but is not limited to, bioavailable substances of phosphorus, molybdenum, selenium, zinc, copper, cobalt, iron, nickel, manganese, vanadium, calcium, potassium, sulfur, chlorine, silicon, magnesium, sodium, nitrogen, boron, or a combination thereof. Bioavailable substances of the above nutrients include, but are not limited to, MoO 2 -, SeO 2 - 、Zn 2+ 、ZnCl - 、CuCO 3 、Co 2+ , Fe 2+ , Fe 3+ 、Ni 2+ 、NiCl + , Mn 2+ 、MnCl + 、HVO 4 2- , Ca 2+ , K+, SO 4 2- , Cl - 、SiOH 4 Mg 2+ 、Na + NH 4+ 、NO 3 - , H 3 BO 3 and B 4 O 7 2- In one embodiment, the at least one nutrient domain includes at least one phosphate domain as a bioavailable source of phosphorus. Suitable phosphates for the bioavailable source include, but are not limited to, DAP, MAP, granular TSP, granular SSP, or a combination thereof.

[0137] At least one suitable biological additive domain includes but is not limited to humus, fulvic acid, live microorganisms, microbial metabolites, plant extracts, exogenous plant hormones or combinations thereof. Any suitable modification of the preparation containing humic acid or fulvic acid or any material derived from organic matter and containing multiple humic acid and / or fulvic acid species can be used. Microorganisms may include but are not limited to Rhodopseudomonas spp., Bacillus spp., Pseudomonas spp., Saccharomyces spp., Aspergillus spp., Candida spp., Streptococcus spp., Lactobacillus spp. or combinations thereof. Plant extracts may include but are not limited to plant hormones, quinols, plastoquinones, flavonoids, metabolites promoting plant growth or combinations thereof. Exogenous plant hormones may include, but are not limited to, IDAA, gibberellins, abscisic acid, auxins, jasmonates, brassinosteroids, cytokinins, salicylic acid, or a combination thereof.

[0138] At least one suitable pesticide domain includes but is not limited to herbicides, insecticides, fungicides, nematicides or combinations thereof. Suitable herbicides include but are not limited to sulfonylureas, HPPD inhibitors, chloroacetamides, PPO inhibitors, phenylureas, triazines or combinations thereof. Suitable insecticides include but are not limited to organophosphates, ureas, pyrethrins, neonicotinoids, spinosins, indoxacarb, diamides or combinations thereof. Suitable bactericides include but are not limited to strobilurines, pyrimidines, triazoles, dicarboximides or combinations thereof. Suitable nematicides include but are not limited to avermectins, carbamates, organophosphates or combinations thereof.

[0139] At least one adsorbent domain may include, but is not limited to, a zeolite, a zeolite-type, or a combination thereof.

[0140] In one embodiment, the at least one supplementation domain 3 comprises at least one phosphate domain and at least one, at least two or each of: an additional nutrient domain other than phosphate, at least one pesticide domain, at least one biological additive domain or a combination thereof.

[0141] The dispersible activated bauxite particle 1 may include at least one layer disposed on the dispersible activated bauxite particle 1, wherein the at least one layer is at least one nutrient layer, at least one pesticide layer, at least one biological additive layer, at least one adsorbent layer, or a combination thereof.

[0142] At least one activated bauxite domain 2 and at least one supplementary domain may be uniformly or non-uniformly distributed within the particle in the dispersible activated bauxite particle 1. At least one activated bauxite domain 2 and at least one supplementary domain 3 may be uniformly or non-uniformly distributed between particles in the dispersible activated bauxite particle 1.

[0143] The dispersible activated bauxite particles 1 may be placed on seeds as a coating.

[0144] refer to Figure 5 In one embodiment, the bonded dispersible activated bauxite particle 1 comprises at least one activated bauxite domain 2, and at least one supplemental domain 3, wherein the at least one activated bauxite domain 2 and the at least one supplemental domain 3 are present as distinct domains cohesively agglomerated together in the bonded dispersible activated bauxite particle 1. The at least one supplemental domain 3 may be a phosphate domain 3 as the at least one nutrient domain 3. The at least one phosphate domain 3 may include, but is not limited to, MAP, DAP, granular TSP, granular SSP, or a combination thereof.

[0145] At least one activated bauxite domain 2 and at least one phosphate domain 3 may be uniformly or non-uniformly distributed within the particle in the bonded dispersible activated bauxite particles 1. At least one activated bauxite domain 2 and at least one supplemental domain 3 may be uniformly or non-uniformly distributed within the particle in the bonded dispersible activated bauxite particles 1.

[0146] In one embodiment, each of the at least one activated bauxite domains 2 is surrounded by at least 50%, or by at least 60%, or by at least 70%, or by at least 80%, or by at least 90%, or by at least 95%, or by at least 99%, or by completely surrounded by at least one complementary domain 3.

[0147] The dispersible activated bauxite particles 1 may have any suitable weight ratio of bauxite to phosphate, including but not limited to a weight ratio of 10:1 to 1:10, or 8:1 to 1:8, or 7:1 to 1:7, or 6:1 to 1:6, or 5:1 to 1:5, or 4:1 to 1:4, or 3:1 to 1:3, or 2:1 to 1:2, or 3:1 to 1:1, or 1:1 to 1:3, or about 2:1, or about 1:1, or about 1:2, or any sub-range or combination of ranges thereof.

[0148] The dispersible activated bauxite particles 1 may further include at least one of a water-soluble binder, a suspending agent or an emulsifier. In one embodiment, the dispersible activated bauxite particles 1 include 1-40 wt%, or 5-35 wt%, or 5-15 wt%, or 10-20 wt%, or 15-25 wt%, or 20-30 wt%, or 25-35 wt%, or any sub-range or combination thereof of a water-soluble binder. Suitable water-soluble binders include, but are not limited to, calcium lignin sulfonate, ammonium lignin sulfonate or a combination thereof. Suitable suspending agents include, but are not limited to, polysaccharides, inorganic salts, carbomers or a combination thereof. Suitable emulsifiers include, but are not limited to, plant derivatives such as gum arabic, tragacanth, agar, pectin, carrageenan or lecithin, animal derivatives such as gelatin, lanolin or cholesterol, semi-synthetic agents such as methylcellulose or carboxymethylcellulose, synthetic agents such as benzalkonium chloride, benzethonium chloride, alkaline soaps (including sodium oleate or potassium oleate), amine soaps (including triethanolamine stearate), detergents (including sodium lauryl sulfate, sodium dioctyl sulfosuccinate or sodium docusate), sorbitan esters, polyethylene oxide derivatives of sorbitan esters, glycerides, or combinations thereof. In another embodiment, the dispersible activated bauxite particles 1 do not contain a water-soluble binder, a suspending agent, an emulsifier, any two or all of the above.

[0149] The dispersible activated bauxite particles 1 may further include at least one additional domain present as a different domain. Suitable additional domains include, but are not limited to, at least one nutrient domain, at least one pesticide domain, at least one biological additive domain, at least one adsorbent domain, or a combination thereof. In the dispersible activated bauxite particles 1, at least one additional domain may be cohesively agglomerated with at least one activated bauxite domain 2 and at least one supplementary domain 3, the at least one additional domain may be agglomerated with the agglomerated at least one activated bauxite domain 2 and at least one supplementary domain 3, at least one additional domain may be coated onto at least one activated bauxite domain 2 and at least one supplementary domain 3, coated in the dispersible activated bauxite particles 1 individually or in the form of aggregation, at least one additional domain may be mixed with the dispersible activated bauxite particles 1, or a combination thereof. As a non-limiting example, in one embodiment, the coherent dispersible activated bauxite particles 1 may include at least one nutrient domain coherently agglomerated with at least one bauxite domain 2 and at least one phosphate domain 3; at least one pesticide domain coherently agglomerated with at least one nutrient domain, at least one activated bauxite domain 2 and at least one phosphate domain 3; and at least one biological additive domain coated on at least one pesticide domain coherently agglomerated with at least one nutrient domain, at least one activated bauxite domain 2 and at least one phosphate domain 3.

[0150] The bauxite particles constituting the activated bauxite domain 2 may have any suitable size. In one embodiment, in order to maintain the adsorption capacity for phosphate and optimize the size of the bauxite particles penetrating the soil profile by surface application, the preferred size of the activated bauxite particles is less than about 300 μm, or less than about 150 μm, or less than about 100 μm, or less than about 75 μm, or less than about 50 μm, or less than about 25 μm, or less, or any sub-range or combination thereof.

[0151] The dispersible activated bauxite particles 1 may further include mineral particles. The mineral particles may be cohesively agglomerated in the dispersible activated bauxite particles 1, cohesively agglomerated with the dispersible activated bauxite particles 1, or mixed with the dispersible activated bauxite particles 1.

[0152] In one embodiment, the dispersible activated bauxite particles 1 comprise by weight 5-80% activated bauxite domains 2, 10-95% supplementary domains 3, and optionally 1-50% water-soluble binder, or 5-50% activated bauxite domains 2, 10-95% supplementary domains 3, and optionally 1-50% water-soluble binder, or 30-40% activated bauxite domains 2, 30-40% supplementary domains 3, and 20-40% water-soluble binder, or 35% activated bauxite domains 2, 35% supplementary domains 3 and 30% water-soluble binder. In another embodiment, the dispersible activated granules 1 comprise or consist of 5-50% by weight of activated bauxite domains 2, 10-70% of supplementary domains 3, up to 50% of a water-soluble binder, and up to 20% surfactants and emulsifiers in total.

[0153] The dispersible activated bauxite particles 1 may have any suitable size (measured by diameter based on the median value within the sample). Suitable sizes of the dispersible activated bauxite particles 1 may include, but are not limited to, about 0.4 mm to about 4.0 mm, or about 0.4 mm to about 1.2 mm, or about 0.9 mm to about 1.5 mm, or about 1.2 mm to about 1.8 mm, or about 1.5 mm to about 2.1 mm, or about 1.8 mm to about 2.4 mm, or about 2.1 mm to about 2.7 mm, or about 2.4 mm to about 3.0 mm, or about 2.7 mm to about 3.3 mm, or about 3.0 mm to about 3.6 mm, or about 3.3 mm to about 4.0 mm, or about 0.4 mm, or about 0.5 mm, or about 0.6 mm, or about 0.7 mm, or about 0.8 mm, or about 0.9 mm, or about 1.0 mm, or about 1.1 mm, Or about 1.2mm, or about 1.3mm, or about 1.4mm, or about 1.5mm, or about 1.6mm, or about 1.7mm, or about 1.8mm, or about 1.9mm, or about 2.0mm, or about 2.1mm, or about 2.2mm, or about 2.3mm, or about 2.4mm, or about 2.5mm, or about 2.6mm, or about 2.7mm, or about 2.8mm, or about 2.9mm, or about 3.0mm, or about 3.1mm, or about 3.2mm, or about 3.3mm, or about 3.4mm, or about 3.5mm, or about 3.6mm, or about 3.7mm, or about 3.8mm, or about 3.9mm, or about 4.0mm, or any sub-range or combination thereof. In a non-limiting example, a golf green may use dispersible activated bauxite particles 1 of about 0.5mm to about 0.8mm. In another non-limiting example, corn can use about 2.4 mm dispersible activated bauxite particles 1 by broadcast application. In a third non-limiting example, any crop applied with a strip tiller can use about 1.5 mm dispersible activated bauxite particles 1 . In one embodiment, suitably, e.g. for application as a suspension, the dispersible activated bauxite particles 1 are micronized and have a particle size measured by maximum particle size of less than about 200 μm, or less than about 150 μm, or less than about 100 μm, or less than about 75 μm, or less than about 1 μm, or less than about 1 μm, or less than about 50 μm, or less than about 25 μm, or less than about 10 μm, or less than about 5 μm, or less than about 2 μm, or less than about 1 μm, or less than about 0.75 μm, or less than about 0.5 μm, or less than about 0.25 μm, or less than about 0.1 μm, or less than about 0.05 μm, or less than about 0.01 μm.

[0154] Based on the total weight of the at least one activated bauxite domain 2, the at least one activated bauxite domain 2 may have an alumina content of at least 35 wt%, or at least 40 wt%, or at least 45 wt%, or at least 50 wt%, or at least 55 wt%. Based on the total weight of the at least one activated bauxite domain 2, the at least one activated bauxite domain 2 may have a total content of aluminum oxide and iron oxide of at least 55 wt%, or at least 60 wt%, or at least 65 wt%, or at least 70 wt%, or at least 75 wt%. The at least one activated bauxite domain 2 may include activated mineral bauxite that has not been chemically modified with NaOH. The at least one activated bauxite domain 2 may include at least one of activated laterite-type bauxite or activated karst-type bauxite.

[0155] In one embodiment, the dispersible activated bauxite particles 1 include activated bauxite particles and a water-soluble binder that agglomerates a plurality of activated bauxite particles into the dispersible activated bauxite particles 1. The activated bauxite particles are not chemically modified with NaOH.

[0156] Based on the total weight of the activated bauxite particles, the activated bauxite particles may have an alumina content of at least 35% by weight, or at least 40% by weight, or at least 45% by weight, or at least 50% by weight, or at least 55% by weight. Based on the total weight of the activated bauxite particles, the activated bauxite particles may have a total content of at least 55% by weight, or at least 60% by weight, or at least 65% by weight, or at least 70% by weight, or at least 75% by weight of alumina and iron oxide. The activated bauxite particles may include at least one of activated laterite bauxite or activated karst bauxite. The dispersible bauxite particles 1 may further include at least one of a suspending agent or an emulsifier. The dispersible bauxite particles 1 may have a moisture content of less than 10%, or less than 8%, or less than 6%, or less than 5%, or less than 4%, or less than 3%, or less than 2%, or less than 1% by weight. The dispersible bauxite particles 1 may have any suitable size, including but not limited to a size less than 0.6 mm, or less than 0.5 mm, or less than 0.4 mm, or less than 0.3 mm, or less than 0.2 mm, or less than 0.1 mm.

[0157] Example

[0158] Experimental methods

[0159] Three granulation studies were conducted to obtain the data disclosed herein. All were conducted in the Large Scale Pilot Plant ("LSPP") at the International Fertilizer Development Center ("IFDC"). As a pre-neutralization step for chemical granulation, the general configuration of the plant is as follows Figure 1Steam granulation is also accomplished on the same system, although without the use of a pre-neutralizer.

[0160] Phosphoric acid was stored in two 4,150L stainless steel conical bottom tanks (Hall tanks). A centrifugal pump was used to recirculate the phosphoric acid in the storage tanks for homogenization before transferring to a 1,300L stainless steel feed tank. The phosphoric acid in the feed tank was recirculated to prevent solid precipitation. A centrifugal pump was used to transfer the phosphoric acid from the feed tank to the reactor.

[0161] During the first two experiments, phosphoric acid and ammonia reacted to produce NH 3 :H 3 PO 4 Ammonium phosphate slurry with a molar ratio of approximately 0.55:1. A magnetic flowmeter was used to control the flow of phosphoric acid to the pre-neutralizer. The flow was measured every 30 minutes using a stopwatch, a beaker, and a balance. Phosphoric acid was fed through a 1.27 cm diameter pipe and discharged into the pre-neutralizer through a funnel located on the pre-neutralizer lid. Ammonia was fed through a drilled tube injector located at the bottom of the pre-neutralizer. The ammonia injector had 10 holes, each with a diameter of 4.76 mm, drilled on the pipe toward the bottom of the container. An armored rotor flowmeter was used to measure the ammonia flow. When necessary, tap water was supplied through a 1.27 cm diameter pipe and monitored by a rotor flowmeter; however, the flow was checked manually every 30 minutes.

[0162] The pre-neutralizer was 61 cm in diameter and 201 cm high with a 9 cm shallow conical bottom. The pre-neutralizer was equipped with a variable speed agitator equipped with three axial flow thrust turbines. A screw variable speed pump was used to transfer the ammonium phosphate slurry from the pre-neutralizer to the drum granulator. The pump speed was varied to maintain the calculated slurry flow rate as closely as possible. The slurry was sprayed using a Spraying Systems Whirljet #15 hollow cone nozzle and discharged 51 cm from the feed end of the granulator.

[0163] The exhaust fan is used to clean the gas from the pre-neutralizer through a spray scrubber before discharging it to the atmosphere. Water is used as the scrubbing medium. The exhaust fan and scrubber system are coated with fluorine-resistant reinforced polyester. The scrubbing liquid is discharged into a collection tank.

[0164] In two granulation studies, The granulator was fed with various bauxite materials by a solid feeder which discharged the bauxite materials into a receiver in the granulator elevator where they were mixed with recycled materials and then entered the granulator. The flow was manually checked every 30 minutes. Three different bauxite materials were used, which were from three different geographical regions and were identified as "Bauxite #1", "Bauxite #2" and "Bauxite #3".

[0165] The granulator was a drum type granulator, 92 cm in diameter and 180 cm long. A 15 cm retaining dam was located 25.4 cm from the discharge end of the granulator. The granulator was operated at an angle of 1.5 degrees to the horizontal. Gaseous ammonia was fed into the granulator through a drilled stainless steel distributor (sprayer) immersed under the rolling bed of material. The target NH 3 :H 3 PO 4 The molar ratio is about 1 : 1. Steam and / or water are optionally added to the granulator through a drilled sprayer to control the granule population.

[0166] The gas extracted from the granulator was treated in a once-through venturi-type scrubber before being discharged to the atmosphere. The scrubbing system used water as the scrubbing medium and was a reinforced polyester venturi-type scrubber with a reinforced polyester recirculating seal tank with a capacity of approximately 227 liters, a circulation pump, and a 316L stainless steel fan. The scrubbing liquid was not returned to the process; it was sent to a sump after each test.

[0167] The moist granular material from the granulator is discharged by gravity into a rotary drum type dryer measuring 92 cm in diameter and 730 cm in length. The rotating and cascading material bed in the dryer is dried using a co-current air flow. A direct flame combustion chamber burning natural gas is located at the inlet (material feed end) of the dryer. The operating temperature of the dryer is indirectly controlled by measuring the temperature of the dryer discharge material and adjusting the air to gas ratio of the combustion chamber to maintain the desired operating temperature, although the temperature setting can be modified manually. The dryer operates at an angle of inclination of 2.0 degrees to the horizontal and is equipped with a belt for vibration inducing hammers.

[0168] The dryer exhaust air / gas duct is equipped with a cyclone dust collector located between the dryer exhaust and the dryer fan. The dust collected in the dryer cyclone is not returned to the process and is weighed before disposal. The gas extracted from the dryer is treated in a wet scrubber before being discharged to the atmosphere. The scrubbing system uses water as the scrubbing medium and includes a 316L stainless steel recirculation tank with a capacity of approximately 4,200L, a stainless steel recirculation pump and a 316L stainless steel fan. The air flow through the dryer is 3,000 to 4,000 cubic meters per hour. The scrubbing liquid produced is not returned to the process but is sent to a wastewater pond.

[0169] A centrifugal bucket elevator is used to transfer material from the dryer to an inclined double-deck mechanical vibrating screening system. The screen housing is equipped with a Ty-Rod 4.75mm oversize screen and a Ty-Rod 2.36mm undersize screen to produce product in the size range of 2.36mm to 4.75mm. The oversize material from the screening system is conveyed to a chain mill.

[0170] Crushed material discharged from the chain mill is returned to the screening system. When appropriate, undersized material from the screening system is returned (recirculated) to the granulator along with controlled partial product size material to maintain granulation control. Product size material from the screening system is transferred to a product cooler that operates with a down stream airflow to a fugitive dust collection system. Product size material is collected in 1 metric ton bags.

[0171] Dust from elevators, screening systems, product coolers and conveyors is collected by a fugitive dust collection system. The fugitive dust collection system consists of a network of collection ducts that combine before entering a cyclonic type dust collector and are discharged to the atmosphere via a 316L stainless steel fan. The airflow through the fugitive dust system ranges from 1,000 to 1,200 cubic meters per hour. The dust collected in the cyclone is not returned to the process but is weighed before disposal.

[0172] Process data for each test was collected every 30 minutes. Where possible, depending on operating conditions, mid-day product samples, composite end-of-day product samples, and selected half-hourly samples were collected and evaluated in IFDC’s chemical laboratory to determine their chemical composition.

[0173] The examples were prepared by a standard granulated monoammonium phosphate production process where phosphoric acid was placed in an acid buffer tank 10 and then reacted with ammonia in a reaction vessel 20 to form monoammonium phosphate. The process was conducted in the trials using a pre-neutralizer apparatus. To achieve steam granulation, steam was injected into the rolling bed of the granulator. All material feeds were monitored and used to calculate the feed to material ratio. Alumina was mixed with the recycle feed and fed to the granulator 30 at the desired ratio, except for two trials where the alumina was fed directly into the pre-neutralizer vessel and granulated as part of the slurry fed to the granulator 30.

[0174] Viscosity was measured using a Brookfield Ametek Dial Reading Viscometer, Model LVT.

[0175] All product samples collected at the end of each test cycle were analyzed for total nitrogen, total P 2 O 5 , water-soluble P 2 O 5 , citrate soluble P 2 O 5 、Alumina (Al 2 O 3 ) and moisture content analysis. All chemical analyses were performed according to AOAC International methods, except for total nitrogen which was determined using a combustion analyzer. Moisture content was determined using the vacuum dessicator method.

[0176] The bonded dispersible granules 1 are characterized by particle size analysis, crush strength, abrasion resistance and impact resistance as summarized in Table 1. Particle size analysis was performed using the sieving method outlined in procedure IFDC S-107-1 in the Manual for Determining Physical Properties of Fertilizer (IFDC R-10). This method determines the particle size index (SGN) and the uniformity index (UI). The particle crush strength was determined using a force sensor according to procedure IFDC S-115 in the Manual for Determining Physical Properties of Fertilizer (IFDC R-10). Abrasion resistance was determined by rolling the particles next to a steel ball according to procedure IFDC S-116 in the Manual for Determining Physical Properties of Fertilizer (IFDC R-10). Impact resistance was determined by impacting the particles in a bagging system according to procedure IFDC S-118 in the Manual for Determining Physical Properties of Fertilizer (IFDC R-10).

[0177] Study 1

[0178] Monoammonium phosphate (MAP) was produced on this system by chemical granulation to standardize the production parameters. Bauxite #1 was introduced into the system at different input inclusion rates (10.31%, 20.63%, 30%, 40% and 50%).

[0179] Study 2

[0180] The granulated MAP was ground into powder with particle size distribution ranging from -100 mesh to 4 mm. The powdered MAP was granulated again by steam granulation in the IFDCL SPP system to standardize the production parameters. Bauxite #1 was then introduced into the system at different input inclusion rates (10.31%, 20.63%, 30%, 40% and 50%).

[0181] Study 3

[0182] Monoammonium phosphate (MAP) was produced on this system by chemical granulation to standardize production parameters. Bauxite #1 was introduced into the system at different input inclusion rates (20.63%, 40%, and 40%). The remaining material in the system was discharged and bauxite #2 was introduced at the same input inclusion rate. Similarly, the material in the system was discharged and bauxite #3 was introduced at the same input inclusion rate.

[0183] Phosphate release studies

[0184] The phosphate release properties of the granulated material in Study 1 were evaluated in water. The phosphate release curve was obtained by placing a specified weight of granules (0.3 g phosphate) in 50 mL of deionized water and monitoring the phosphate concentration in the water reservoir at specified time points. Aliquots of liquid were removed and replaced from the liquid reservoir at regular time points. The filtrate phosphate concentration was analyzed colorimetrically by the Murphy and Riley (1962) procedure using a SEAL AQ 400 automatic analyzer, method EPA-118-ARev.5 (SEAL Analytical, 2004).

[0185] refer to Figure 6 , the predicted available P 2 O 5 The available P of the measured particles produced 2 O 5 For comparison, the predicted available P 2 O 5 The output bauxite content based on the input bauxite feedstock content is equal to the output bauxite content in the finished pellets. Since the slope for m=1.455 is statistically greater than the slope for m=1, this indicates that a mass loss is observed from the input bauxite. Since bauxite "activation" is defined as the loss of bound water from the bauxite crystal structure, this change demonstrates that crystal water is removed from the bauxite during the pelletizing process.

[0186] refer to Figure 7, shows the thermogravimetric analysis ("TGA") curves of the produced bauxite-embedded ammonium phosphate particles, the produced monoammonium phosphate and the original bauxite over the temperature range of 25°C to 1000°C (Bauxite #1). The original bauxite curve clearly shows that trihydrate water is removed in the temperature range of 250°C to 375°C and monohydrate water is removed in the temperature range of 375°C to 550°C. The TGA curves of the particles do not show the appropriate proportion of trihydrate water or monohydrate water loss in the appropriate temperature range, indicating that the bound water has been lost before the test, proving that the bound water is removed during the pelletizing process.

[0187] The type of granulation has an effect on the degree of activation of the bauxite as shown in Table 1. Chemical granulation showed more loss of crystal water from the bauxite than steam granulation. The dryer chamber temperature also had an effect on activation as shown in Table 2, indicating that some loss of crystal water occurred in the rotary dryer.

[0188] Table 1. Effect of granulation on bauxite activation

[0189]

[0190] Table 2. Effect of drying temperature on bauxite activation

[0191]

[0192] refer to Figure 8 , the measured total nitrogen content of the particles was compared with the total P 2 O 5 Since MAP is designed to be produced at a 1:1 molar ratio, the slope should remain the same regardless of the additional input (in this case, based on total P 2 O 5 The slope is expected to be m = 4.94, based on the mass input divided by the total nitrogen mass input (53.3 / 10.8). However, when bauxite was introduced at different concentrations, the slopes for both chemical and steam granulation were statistically lower than m = 4.94, indicating that ammonia demand was reduced compared to phosphoric acid during the manufacturing process. This suggests that phosphoric acid chemically reacts with bauxite and forms reactive sites more readily than ammonia molecules. The introduction of bauxite reduced the amount of ammonia required to complete granulation.

[0193] refer to Fig. 9 , the addition of bauxite reduces the amount of ammonia required to complete granulation. During the manufacturing process, equipment operators regularly adjust the material input to maintain adequate granulation. As more bauxite is input as raw material, the ammonia demand decreases as bauxite is input to below the expected input rate.

[0194] refer to Fig.10, for pellets produced by chemical granulation, the reduction in pellet nitrogen content from predicted amounts is plotted as a function of the amount of activated bauxite present in the pellets. The reduction in ammonia input carries over to the final pellet nitrogen content, further demonstrating that bauxite reduces nitrogen demand in manufacturing.

[0195] refer to Fig.11 , for granules produced by steam granulation, the reduction in granule nitrogen content from the expected amount is plotted as a function of the amount of activated bauxite present in the granules. Although a reduction in nitrogen was observed, the rate of reduction was lower than for granules produced by chemical granulation, suggesting that the level of bauxite activation has an effect on the effectiveness of the bauxite interaction with phosphoric acid.

[0196] refer to Fig.12 ,The results show that the higher the activation degree of bauxite, the greater the adsorption of phosphate.

[0197] refer to Fig.13 , P 2 O 5 The availability was compared with the activated bauxite content of the granules produced by chemical granulation. When the granules contained a larger amount of bauxite, the granules P 2 O 5 The transition from water soluble to citrate soluble indicates that the phosphate molecules interact with the solid bauxite particles in a controlled manner.

[0198] refer to Fig.14 , P 2 O 5 The availability was compared with the activated bauxite content of the granules produced by steam granulation. When the granules contained a larger amount of bauxite, the granules P 2 O 5 The transition from being water soluble to being citrate soluble. This transition suggests that the phosphate molecules interact with the solid bauxite particles in a controlled manner. However, this transition occurred more slowly when the particles were produced by steam granulation rather than chemical granulation, further demonstrating that the amount of crystallization water removed from the bauxite lattice plays an important role in the amount of phosphate that interacts with it.

[0199] refer to Fig.15 , comparison of the percentage of phosphate release from granules with different bauxite inclusion rates produced by chemical granulation over a period of 66 days showed that the phosphate release rate slowed down with increasing bauxite inclusion in the granules.

[0200] Table 3. Properties of selected bauxites tested

[0201]

[0202]

[0203] refer to Fig.16 , the crystal water loss during chemical granulation was calculated for each evaluated bauxite. To standardize the manufacture, the dryer temperature was all set at 450°C and the bauxite input was 30% on a dry manufacture basis.

[0204] refer to Fig.17 , the loss on ignition was calculated for each bauxite present in the pellets after chemical granulation. These differences indicate that different bauxites are “activated” to different levels when undergoing the same process, mainly due to the physicochemical properties of the bauxites.

[0205] refer to Fig.18 , measured the differences in the propensity of various evaluated bauxites to volatilize water of crystallization from the crystal lattice. Bauxite #1 showed lower loss on ignition ("LOI") at lower temperatures than Bauxite #2 and Bauxite #3, indicating an increased activation tendency. These differences suggest that the iron oxide content may play a role in the activation tendency of bauxites.

[0206] refer to Fig.19 There is a correlation between the content of activated bauxite and the reduction of ammonia input during chemical granulation. In this experiment, granulation was achievable without a significant reduction in ammonia input.

[0207] refer to Fig. 20 , the ammonia reduction calculated based on the ammonia-phosphoric acid imbalance determined by titration of the granules leaving the granulator was compared with the activated bauxite content in the granules. Fig.18 ), but the ammonia reduction increased significantly with increasing levels of activated bauxite in all three bauxites tested. This trend suggests that when greater amounts of bauxite are included, there must be greater amounts of free, unreacted ammonia in the granules, indicating that bauxite outcompetes ammonia molecules for phosphate sites. Ultimately, this result suggests that ammonia levels should unintuitively decrease when co-granulating with bauxite.

[0208] refer to Fig.21 , the calculated ammonia reduction is calculated from the total P 2 O 5 and total nitrogen were determined by analysis and compared with the activated bauxite content in the finished pellets. Fig.18 ), but the ammonia reduction increased significantly with increasing activated bauxite content in all three bauxites tested. This is because of the tendency to maintain free unreacted ammonia within the granules immediately after granulation ( Fig.19 ), indicating that a significant portion of the unreacted ammonia is volatilized throughout the manufacturing process. Due to the environmental consequences of this ammonia volatilization, contrary to expectation, it is desirable to reduce the ammonia input in proportion to the bauxite input.

[0209] refer to Figure 22-24 , measured for granules produced by chemical granulation ( Fig. 22 )Bauxite #1, ( Fig.23 ) Bauxite #2 and ( Fig.24 )Total P in bauxite #3 2 O 5 Water-soluble P 2 O 5 , citrate soluble P 2 O 5 and citrate-insoluble P 2 0 5 With the increase of bauxite content, bauxite #1 shows a change from water-soluble P 2 O 5 Citrate soluble P 2 O 5 The largest tendency for the shift was observed, which suggests that the level of bauxite activation plays a role in the controlled release properties of the phosphate.

[0210] A comparison of the properties of each of the pellets produced is given in Table 4. The addition of any of the three bauxites evaluated did not have a deleterious effect on pellet quality.

[0211] Table 4. Characteristics of the produced particles

[0212]

[0213] refer to Fig.25 The granulation efficiency of Bauxite #1-MAP, Bauxite #1-MAP, and Bauxite #1-MAP was measured by the ratio of oversized particles, right-sized particles, and undersized particles produced when leaving the rotary dryer. These results suggest that there may be scalability issues in obtaining granulation properties above 50% bauxite inclusion under the conditions studied.

[0214] Although the foregoing description illustrates and describes exemplary embodiments, it will be appreciated by those skilled in the art that various changes may be made and equivalents may be substituted for its elements without departing from the scope of the present invention. In addition, many modifications may be made to adapt specific situations or materials to the teachings of the present invention without departing from the basic scope of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed as the best mode for carrying out the present invention, and the present invention will include all embodiments falling within the scope of the appended claims.

Claims

1. Dispersible activated bauxite particles comprising: at least one activated bauxite domain; as well as at least one supplemental domain selected from the group consisting of at least one nutrient domain, at least one pesticide domain, at least one biological additive domain, at least one sorbent domain, and combinations thereof, Wherein the at least one bauxite domain and the at least one supplementary domain are present in the dispersible activated bauxite particles as distinct domains aggregated together.

2. The dispersible activated bauxite particle of claim 1, wherein the dispersible activated bauxite particle is a bonded dispersible activated bauxite particle and the at least one activated bauxite domain and the at least one supplemental domain are present in the bonded dispersible activated bauxite particle as distinct domains that are bondedly agglomerated together such that the bonded dispersible activated bauxite particle has a bonded dispersible bauxite particle crush strength of at least 5 lbf.

3. The dispersible activated bauxite particles according to claim 1, wherein the dispersible activated bauxite particles are agglomerated dispersible activated bauxite particles.

4. The dispersible activated bauxite particle of claim 1, wherein the at least one supplementation domain comprises at least one nutrient domain, and the at least one nutrient domain comprises at least one additive selected from the group consisting of bioavailable substances of phosphorus, molybdenum, selenium, zinc, copper, cobalt, iron, nickel, manganese, vanadium, calcium, potassium, sulfur, chlorine, silicon, magnesium, sodium, nitrogen, boron, and combinations thereof.

5. The dispersible activated bauxite particle of claim 4, wherein the at least one nutrient domain comprises at least one phosphate domain as a bioavailable source of phosphorus.

6. The dispersible activated bauxite particle of claim 5, wherein the at least one phosphate domain is selected from the group consisting of diammonium phosphate, monoammonium phosphate, triple superphosphate, superphosphate, nitrophosphate, and combinations thereof.

7. The dispersible activated bauxite particle of claim 1, wherein the at least one supplemental domain comprises at least one biological domain, and the at least one biological domain comprises at least one additive selected from the group consisting of humic substances, fulvic acid, live microorganisms, microbial metabolites, plant extracts, exogenous plant hormones, and combinations thereof.

8. The dispersible activated bauxite particle of claim 1, wherein the at least one supplemental domain comprises at least one pesticide domain, and the at least one pesticide domain comprises at least one additive selected from the group consisting of herbicides, insecticides, fungicides, nematicides, and combinations thereof.

9. The dispersible activated bauxite particle of claim 1, wherein the at least one supplemental domain comprises at least one sorbent domain, and the at least one sorbent domain comprises at least one additive selected from the group consisting of zeolites, zeolite-types, and combinations thereof.

10. The dispersible activated bauxite particle of claim 1, wherein the at least one supplemental domain comprises at least one phosphate domain and at least one of: an additional nutrient domain other than phosphate, at least one pesticide domain, at least one biological additive domain, and combinations thereof.

11. The dispersible activated bauxite particle of claim 1 , wherein the at least one activated bauxite domain and the at least one supplemental domain are uniformly distributed within the particle in the dispersible activated bauxite particle.

12. The dispersible activated bauxite particle of claim 1, wherein the at least one activated bauxite domain and the at least one supplemental domain are interparticle-homogeneously distributed in the dispersible activated bauxite particle.

13. The dispersible activated bauxite particle of claim 1 having an activated bauxite domain:supplementary domain weight ratio of 5:1 to 1:

5.

14. The dispersible activated bauxite particles of claim 1 further comprising at least one of a water soluble binder, a suspending agent, or an emulsifier.

15. The dispersible activated bauxite particle of claim 1, further comprising at least one additional domain as a different domain, wherein the at least one additional domain is selected from the group consisting of at least one nutrient domain, at least one pesticide domain, at least one biological additive domain, at least one sorbent domain, and combinations thereof.

16. The dispersible activated bauxite particle of claim 15, wherein the at least one additional domain is cohesively agglomerated with at least one activated bauxite domain and at least one supplementary domain in the dispersible activated bauxite particle.

17. The dispersible activated bauxite particle of claim 15, wherein the at least one additional domain is agglomerated with at least one activated bauxite domain and at least one supplementary domain in the dispersible activated bauxite particle.

18. The dispersible activated bauxite particle of claim 15, wherein the at least one additional domain is coated onto at least one bauxite domain and at least one supplemental domain that are aggregated together.

19. The dispersible activated bauxite particle of claim 1, wherein the at least one activated bauxite domain has an alumina content of at least 35 wt% based on the total weight of the at least one activated bauxite domain.

20. The dispersible activated bauxite particle of claim 1, wherein the at least one activated bauxite domain has a combined content of aluminum oxide and iron oxide of at least 55 wt%, based on the total weight of the at least one activated bauxite domain.

21. The dispersible activated bauxite particle of claim 1, wherein the at least one activated bauxite domain comprises activated mineral bauxite that has not been chemically modified with NaOH.

22. The dispersible activated bauxite particle of claim 1, wherein the at least one activated bauxite domain comprises at least one of activated laterite-type bauxite or activated karst-type bauxite.

23. Dispersible activated bauxite particles comprising: activated bauxite particles; and a water-soluble binder that agglomerates the plurality of activated bauxite particles into dispersible activated bauxite granules, The activated bauxite particles were not chemically modified with NaOH.

24. The dispersible activated bauxite particles of claim 23, wherein the dispersible activated bauxite particles are disposed as a coating on a seed.

25. The dispersible activated bauxite particle of claim 23, wherein the activated bauxite particle has an alumina content of at least 35 wt% based on the total weight of the activated bauxite particle.

26. The dispersible activated bauxite particle of claim 23, wherein the activated bauxite particle has a combined content of aluminum oxide and iron oxide of at least 55 wt%, based on the total weight of the activated bauxite particle.

27. The dispersible activated bauxite particles of claim 23, wherein the activated bauxite particles comprise at least one of activated laterite-type bauxite or activated karst-type bauxite.

28. The dispersible activated bauxite particle of claim 23, further comprising at least one of a suspending agent or an emulsifier.

29. The dispersible activated bauxite particle of claim 23, wherein the dispersible activated bauxite particle has a moisture content of less than 10% by weight.

30. The dispersible activated bauxite particles of claim 23, wherein the dispersible activated bauxite particles have a size less than 0.6 mm.

31. A method of forming coherent dispersible activated bauxite particles comprising: placing at least one acid in an acid buffer tank; reacting at least one acid with ammonia in a reaction vessel to form at least one ammonium salt; introducing bauxite particles in the presence of at least one ammonium salt; co-agglomerating at least one ammonium salt and bauxite particles in a tumbler ammoniation granulator to form cohesive dispersible granules; and Dry bonded dispersible granules, wherein at least one of the bauxite particles and the dry bonded dispersible particles is activated by introducing the bauxite particles in the presence of at least one ammonium salt to form bonded dispersible activated bauxite particles having a bonded dispersible activated bauxite particle crush strength of at least 5 lbf.

32. The method of claim 31, wherein the at least one acid is selected from the group consisting of boric acid, phosphoric acid, sulfuric acid, nitric acid, and combinations thereof, and the at least one ammonium salt is selected from the group consisting of ammonium pentaborate, ammonium phosphate, ammonium sulfate, ammonium nitrate, and combinations thereof.

33. The method of claim 31, wherein introducing the bauxite pellets in the presence of the at least one ammonium salt comprises premixing the bauxite pellets with the at least one acid prior to reacting the at least one acid with the ammonia.

34. The method of claim 31, wherein introducing the bauxite pellets in the presence of at least an ammonium salt comprises adding the bauxite pellets to at least one of an acid buffer tank, a reaction vessel, or a rotary drum ammoniation granulator.

35. The method of claim 31, wherein the reaction vessel is a cross-tube reactor.

36. The method of claim 35, wherein introducing the bauxite pellets in the presence of at least one ammonium salt comprises feeding the bauxite pellets through a cross-tube reactor.

37. The method of claim 35, wherein drying the bound dispersible granules comprises drying the bound dispersible granules in a rotary dryer.

38. The method of claim 37, further comprising introducing the bauxite pellets into a rotary dryer.

39. A method of forming coherent dispersible activated bauxite particles comprising: mixing ground alkaline rock and at least one of phosphoric acid, sulfuric acid or nitric acid in a reactor; reacting ground alkaline rock with at least one of phosphoric acid, sulfuric acid or nitric acid in a reactor, to form at least one of a superphosphate slurry or a nitrophosphate slurry; introducing bauxite particles in the presence of at least one of a superphosphate slurry or a nitrophosphate slurry; co-agglomerating at least one of a superphosphate slurry or a nitrophosphate slurry with bauxite particles in a rotary drum ammoniation granulator to form cohesive dispersible particles; and Dry bonded dispersible granules, wherein at least one of the bauxite particles and the dry bonded dispersible particles are activated by introducing the bauxite particles in the presence of at least one of a superphosphate slurry or a nitrophosphate slurry to form bonded dispersible activated bauxite particles having a bonded dispersible activated bauxite particle crush strength of at least 5 lbf.

40. The method of claim 39, wherein the ground alkaline rock is ground phosphate rock.

41. The method of claim 39, wherein introducing the bauxite pellets in the presence of at least one of a superphosphate slurry or a nitrophosphate slurry comprises premixing the bauxite pellets with at least one of phosphoric acid, sulfuric acid, or nitric acid prior to mixing the at least one of phosphoric acid, sulfuric acid, or nitric acid with the ground alkaline rock.

42. The method of claim 39, wherein introducing the bauxite pellets in the presence of at least one of a superphosphate slurry or a nitrophosphate slurry comprises adding the bauxite pellets to at least one of an acid control tank upstream of the reactor, a basic rock weigh feeder upstream of the reactor, the reactor, or a drum granulator.

43. The method of claim 39, wherein drying the bound dispersible granules comprises drying the bound dispersible granules in a rotary dryer.

44. The method of claim 39, further comprising introducing the bauxite pellets into a rotary dryer.

45. A method of forming coherent dispersible activated bauxite particles comprising: placing at least one acid in a reactor; introducing bauxite particles in the presence of at least one acid; co-agglomerating at least one acid and bauxite particles in a drum granulator to form cohesive dispersible granules; and Dry bonded dispersible granules, wherein at least one of the bauxite particles and the dry bonded dispersible particles is activated by introducing the bauxite particles in the presence of at least one acid to form bonded dispersible activated bauxite particles having a bonded dispersible activated bauxite particle crush strength of at least 5 lbf.

46. ​​The method of claim 45, wherein the at least one acid is selected from the group consisting of boric acid, phosphoric acid, sulfuric acid, nitric acid, and combinations thereof.

47. The method of claim 45, wherein drying the bound dispersible granules comprises drying the bound dispersible granules in a rotary dryer.

48. The method of claim 45, further comprising introducing the bauxite pellets into a rotary dryer.

49. A method of forming coherent dispersible activated bauxite particles comprising: melting at least one of an acidic borate, an acidic phosphate, an acidic sulfate, or an acidic nitrate from a solid form to a liquid form; introducing bauxite particles in the presence of at least one of an acidic borate, an acidic phosphate, an acidic sulfate, or an acidic nitrate; co-agglomerating at least one of an acidic borate, an acidic phosphate, an acidic sulfate, or an acidic nitrate with the bauxite particles in a drum granulator to form cohesive dispersible particles; and Dry bonded dispersible granules, wherein at least one of the bauxite particles and the dry bonded dispersible particles are activated by introducing the bauxite particles in the presence of at least one of an acidic borate, an acidic phosphate, an acidic sulfate, or an acidic nitrate to form bonded dispersible activated bauxite particles having a bonded dispersible activated bauxite particle crush strength of at least 5 lbf.

50. The method of claim 49, wherein the acidic phosphate is selected from the group consisting of monoammonium phosphate, diammonium phosphate, and combinations thereof.

51. The method of claim 49, wherein melting at least one of an acidic borate, an acidic phosphate, an acidic sulfate, or an acidic nitrate comprises and co-agglomerating at least one of an acidic borate, an acidic phosphate, an acidic sulfate, or an acidic nitrate and the bauxite particles comprises a steam pelletizing process.

52. A method of forming agglomerated dispersible activated bauxite particles comprising: physically mixing the bauxite pellets with supplemental pellets selected from the group consisting of nutrient pellets, pesticide pellets, bio-pellets, adsorbent pellets, and combinations thereof; agglomerating bauxite particles with supplemental particles and at least one water-soluble binder to form agglomerated dispersible particles; and The agglomerated dispersible particles are dried at a temperature of at least 250°F to form agglomerated dispersible activated bauxite particles.

53. The method of claim 52, wherein the nutrient particles include bioavailable materials selected from the group consisting of phosphorus, molybdenum, selenium, zinc, copper, cobalt, iron, nickel, manganese, vanadium, calcium, potassium, sulfur, chlorine, silicon, magnesium, sodium, nitrogen, boron, and combinations thereof.

54. The method of claim 53, wherein the nutrient particles include phosphate as the bioavailable form of phosphorus.

55. The method of claim 54, wherein the phosphate is selected from the group consisting of diammonium phosphate, monoammonium phosphate, triple superphosphate, superphosphate, nitrating phosphates, and combinations thereof.

56. The method of claim 52, wherein the bioparticles include components selected from the group consisting of humus, fulvic acid, live microorganisms, microbial metabolites, plant extracts, exogenous plant hormones, and combinations thereof.

57. The method of claim 52, wherein the pesticide pellets include an ingredient selected from the group consisting of herbicides, insecticides, fungicides, nematicides, and combinations thereof.

58. The method of claim 52, wherein the adsorbent particles comprise a member selected from the group consisting of zeolites, zeolite-types, and combinations thereof.

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