Fertilizer and production method

Abstract

A fertilizer and a method for fertilizer production, the method comprising: contacting a tailings material with biomass and an inoculation consortia to form a tailings mixture; mixing the tailings mixture; contacting the tailings mixture with a solution, an aqueous solution or water; aerobically digesting the tailings mixture; and drying the tailings mixture to form fertilizer. The biomass may comprise green material, high nitrogen material and / or woody-browns material. The tailings material may comprise mining tailings, including porphyry tailings, aggregate waste, and / or oxide tailings. The inoculation consortia may comprise one or more of a plurality of microorganism species. The tailings material may comprise a macronutrient and / or micronutrient.

Description

FERTILIZER AND PRODUCTION METHODCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of the filing of U.S. Provisional Patent Application No. 63 / 638,661 , entitled "REPURPOSING OF TAILINGS MATERIAL INTO A BIOMINERAL FERTILIZER USING A MICROBAL-DRIVEN AEROBIC DIGESTION PROCESS", filed on April 25, 2024, and the specification and claims thereof are incorporated herein by reference.BACKGROUND OF THE INVENTIONField of the Invention (Technical Field):

[0002] The present invention relates to a fertilizer and method of making a fertilizer using digestion and mineral tailings and ore.Background:

[0003] Mine or mineral tailings (“mine tailings”) represent the residual material disposed of following metallurgical processing to extract the economic value from metal ore deposits which occur in sufficient quantity and other conditions for commercial sale. The mine tailings are typically collected and maintained in a dam or other impoundment facility or structure (tailings storage facility (“TSF”)) where they can be stored and stabilized for long term management and / or monitoring and environmental management. Likewise, ore is sometimes directly crushed and / or ground and processed to recover minerals or metals.

[0004] Mine tailings typically represent challenges for mining or extraction companies, for communities in the vicinity of a TSF, for governments and regulators, andfor other stakeholders because of the potential risks to environmental safety and personal safety, and the longevity needed to monitor and manage these mine tailings.

[0005] There are situations where tailings material has been reprocessed rather than repurposed using recovery technologies often with beneficiation required to support increased recovery from metals; this is effectively an extension of the original extraction process with improved or new metallurgical processing. In this situation, the new production is primarily for the purpose of producing metals or metal concentrates or minerals for future smelting and / or refining and / or other processing into marketable products and requires further containment of the fresh tailings material e.g., in a TSF. These situations generally have no element of repurposing the tailings material for agricultural purposes.

[0006] What is needed is a method to repurpose tailings and / or ores with bio-metals and rock mineral constituents to produce a fertilizer or other soil supplement which can enhance food quality and soil health at a commercial and / or industrial level.BRIEF SUMMARY OF THE INVENTION

[0007] Embodiments of the invention relate to a method of fertilizer production, the method comprising: contacting a tailings material with biomass and an inoculation consortia to form a tailings mixture; mixing the tailings mixture; contacting the tailings mixture with a solution; aerobically digesting the tailings mixture; and drying the tailings mixture to form fertilizer. In another embodiment, mixing comprises manual mixing. In another embodiment, mixing comprises windrow turning.

[0008] In another embodiment, the biomass comprises a biomass green material. In another embodiment, the biomass comprises a high nitrogen material. In another embodiment, the biomass comprises a woody-browns material. In another embodiment, the method further comprises contacting the tailings material with biochar. In another embodiment, the biomass comprises a carbon to nitrogen ratio of at least about 10:1.

[0009] In another embodiment, the tailings material comprises porphyry ore or tailings. In another embodiment, the tailings material comprises granitic aggregate. In another embodiment, the tailings material comprises lateritic oxide tailings.

[0010] In another embodiment, the inoculation consortia comprises a bacterium. In another embodiment, the inoculation consortia comprises a fungi. In another embodiment, the solution is non-saline. In another embodiment, the solution is an aqueous solution or water. In another embodiment, the tailings mixture is about 50% to about 80% tailings material by weight. In another embodiment, the tailings material comprises a macronutrient. In another embodiment, the tailings material comprises a micronutrient.

[0011] Embodiments of the present invention also relate to a fertilizer composition, the fertilizer composition comprising: a tailings material; the tailings material comprising a macronutrient; the tailings material comprising a micronutrient; a biomass; and inoculation consortia. In another embodiment, the mineral tailings comprise porphyry ore or tailings.

[0012] Further scope of applicability of the present invention will be set forth in part in the detailed description to follow, taken in conjunction with the accompanying drawings, and in part will become apparent to those skilled in the art upon examination of the following, or may be learned by practice of the invention. The objects and advantages of the invention may be realized and attained by means of the instrumentalities and combinations particularly pointed out in the appended claims.BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS

[0013] The accompanying drawings, which are incorporated into and form a part of the specification, illustrate one or more embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are only for the purpose of illustrating one or more embodiments of the invention and are not to be construed as limiting the invention. In the drawings:

[0014] Fig. 1 is a diagram showing mobilization and interaction of the key elemental constituents in the digestion process for fertilizer production, according to an embodiment of the present invention;

[0015] Fig. 2 is a process flow diagram showing a method of fertilizer production, according to an embodiment of the present invention;

[0016] Fig. 3 is a graph showing soil organic matter in copper porphyry tailings, according to an embodiment of the present invention;

[0017] Fig. 4 is a graph showing nitrogen forms in copper porphyry tailings, according to an embodiment of the present invention;

[0018] Fig. 5 is a graph showing phosphorus forms in copper porphyry tailings, according to an embodiment of the present invention;

[0019] Fig. 6 is a graph showing micronutrients in copper porphyry tailings, according to an embodiment of the present invention;

[0020] Figs. 7A and 7B are graphs showing a fertilizer microbiome from copper porphyry tailings, according to an embodiment of the present invention;

[0021] Fig. 8 is a graph showing soil respiration, in copper porphyry tailings, according to an embodiment of the present invention;

[0022] Fig. 9 is a graph showing pH changes for the digestion of granitic aggregate waste, according to an embodiment of the present invention;

[0023] Figs. 10A and 10B are graphs showing organic carbon and CO2 respiration, respectively, for the digestion of granitic aggregate waste, according to an embodiment of the present invention;

[0024] Figs. 11A and 11B are graphs showing total and available nitrogen, respectively, for the digestion of granitic aggregate waste, according to an embodiment of the present invention;

[0025] Figs. 12A and 12B are graphs showing total and available phosphorus, respectively, for the digestion of granitic aggregate waste, according to an embodiment of the present invention;

[0026] Fig. 13 is a graph showing cation and macronutrient concentrations, for the digestion of granitic aggregate waste, according to an embodiment of the present invention;

[0027] Fig. 14 is a graph showing total bacteria and fungi, for the digestion of granitic aggregate waste, according to an embodiment of the present invention;

[0028] Figs. 15A and 15B are graphs showing organic carbon and CO2 respiration, respectively, for the digestion of lateritic oxide tailings, according to an embodiment of the present invention;

[0029] Figs. 16A and 16B are graphs showing total and available nitrogen, respectively, for the digestion of lateritic oxide tailings, according to an embodiment of the present invention;

[0030] Figs. 17A and 17B are graphs showing total and available phosphorus, respectively, for the digestion of lateritic oxide tailings, according to an embodiment of the present invention;

[0031] Fig. 18 is a graph showing cation and macronutrient concentrations for the digestion of lateritic oxide tailings, according to an embodiment of the present invention; and

[0032] Fig. 19 is a graph showing total bacteria and fungi for digestion of lateritic oxide tailings, according to an embodiment of the present invention.DETAILED DESCRIPTION OF THE INVENTION

[0033] Embodiments to of the present invention relate to a method of fertilizer or soil supplement production, the method comprising contacting a tailings or ore material with biomass and an inoculation consortia to form a mixture; mixing the mixture; contacting the mixture with a solution, e.g., an aqueous solution and / or water; and digesting the mixture to form fertilizer. The method may further comprise drying the mixture. Themethod may further comprise contacting the tailings or ore with biochar. The digestion may be an aerobic digestion and / or under aerobic conditions. The fertilizer may be a biomineral fertilizer. The mixture may be a tailings mixture.

[0034] The method may comprise using a biodigestion process that comprising contacting bio-metals and rock mineral constituents available from rock materials having defined chemical and physical properties with biomass. The fertilizer may be nutrient-rich and have intrinsic benefits for soil health that is produced by repurposing tailings material or ore and combining the tailings material with a chemical consortium of microbial inoculants and biomass materials in an aerobic biodigestion process.

[0035] The method may comprise using tailings material from ores or the ore and other minerals comprising a composition suitable for fertilizer production. The tailings or ore may be combined into a tailings mixture comprising food waste, agricultural waste, nitrate-rich foods, woody biomass materials, biochar, and a consortium of microbial inoculants, or combination thereof. The tailings mixture may undergo an aerobic digestion process.

[0036] The fertilizer repurposed from mine tailings ore may have practical and useful applications in both the agricultural and mineral sectors. The repurposing may reduce the cost and risk associated with managing TSFs. The fertilizer may improve plant nutrition and crop yield. The repurposing may have cost-benefits associated with environmental and social improvements by removing tailings from TSFs.

[0037] The fertilizer may be sold into existing commercial markets currently supplied by chemicals and fertilizers. The fertilizer may have application in existing or new markets related to revegetation, restoration, alternative or new land use, and may result in new classification of the tailings material produced from ores and other minerals.

[0038] The method may mitigate or eliminate the environmental and personal safety risks at individual mining sites by repurposing tailings into a new biomineral fertilizer product with viable commercial, agricultural, and / or environmental applications.

[0039] This method may mitigate or eliminate the commercial liabilities and environmental and safety risks at individual mining or mineral sites by repurposing thetailings material. The reduction or elimination may include direct costs for geotechnical and other technical programs and applications to stabilize the TSF and / or the associated management and reporting requirements and costs for the TSF.

[0040] The method may use tailings or ore with a defined bio-metals and rock mineral composition as a feedstock, where elements typically considered deleterious are ingredients to produce a nutrient-rich fertilizer.

[0041] The method may comprise chemical and physical reactions, driven by a consortium of microorganisms and designed to produce the fertilizer.

[0042] The fertilizer produced by the method of the invention may provide benefits such as:(i) reduction of existing environmental costs and liabilities; (ii) reduction in water and overall fertilizer use;(iv) reducing of the carbon footprint the mine and agricultural operators; (v) revegetation and land remediation; and / or(vi) sustainable soil regeneration and land reuse and classification.

[0043] The fertilizer may create sustainable value in environmental and social matters, by making an affordable, quality fertilizer product available in remote or often impoverished areas where the method is deployed in the vicinity of mining or mineral operations. The method may reduce water and overall fertilizer use as compared to traditional fertilizer methods. The method may reduce the carbon footprint by producing lower emissions compared to traditional fertilizer production methods. The method may improve soil health and carbon sequestration, reduce agricultural waste, and reduce transport emissions compared to traditional fertilizer production methods. The method may be applied for environmental improvements for revegetation and restoration into existing and new markets, and for sustainable soil regeneration for new land reuse and classification.

[0044] The term “fertilizer” as used herein means a soil additive or supplement and / or compost useful for enhancing or enriching or fertilizing soil, plants, crops, or other materials.

[0045] The terms “ore” or “ores”, as used herein mean a metal or rock having sufficient enrichment to be extracted economically. The terms “minerals”, “tailings” and “ore” are sometimes used interchangeably herein.

[0046] The term “tailings”, as used herein refers to residual material discarded from metallurgical or mining processing including, but not limited to, ore tailings, rock tailings, aggregate waste, and / or a combination thereof.

[0047] The terms “biodigestion” or “digestion” as used herein mean the chemical and physical reactions and transformation process to reprocess tailings into a fertilizer.

[0048] The terms “batch” or “batches” as used herein means a blend of tailings, biomass, biochar, and consortia of inoculant.

[0049] The terms “mineral” or “minerals” as used herein means an inorganic material and may include, but is not limited to, ore, concentrate, run of mill, tailings, rock, or a combination thereof.

[0050] The tailings material may comprise a macronutrient and / or micronutrient. The macronutrient and / or micronutrient may be derived from the tailings. The macronutrient may include, but is not limited to, calcium (“Ca”), potassium (“K”), magnesium (“Mg”), sodium (“Na”), phosphorus (“P”), silicon (“Si”), or a combination thereof. The micronutrient may include, but is not limited to, boron (“B”), barium (“Ba”), chloride (“Cl”), copper (“Cu”), iron (“Fe”), manganese (“Mn”), molybdenum (“Mo”), sulfur (“S”), selenium (“Se”), zinc (“Zn”), or a combination thereof. The tailings material may also comprise aluminum (“Al”), arsenic (“As”), cadmium (“Cd”), cobalt (“Co”), chromium (“Cr”), nickel (“Ni”), mercury (“Hg”), lead (“Pb”), antimony (“Sb”), tin (“Sn”), or a combination thereof which may be considered deleterious to the process.

[0051] The tailings may comprise a heavy metal including, but not limited to, copper, zinc, molybdenum, and manganese, or a combination thereof. The heavy metal may be an essential metal for protein production in plants, other biological processes, developmental pathways, or a combination thereof. The tailings may comprise a heavy metal at a level that does not adversely affect plant or animal health.

[0052] Turning now to the figures, Fig. 1 shows mobilization and interaction of the key elemental constituents in the digestion process for fertilizer production. Mineral tailings, microbes, and biomass are mixed and digested to induce chemical reactions to form organic nutrients.

[0053] Table 1 details maximum threshold values for key metals useful in accordance with the invention either (i) considered beneficial ingredients for the invention or (ii) deleterious elements.Table 1: Metal Concentrations in Mineral Feedstock

[0054] Fig. 2 shows fertilizer production process 20. Feed 22, e.g., tailings, is passed through conduit 24 where feed 22 may be subjected to quality assurance and / or quality control (“QA / QC”) testing to evaluate the tailings composition. Biomass 28, biochar 32, and inoculant 34 may be subjected to QA / QC 30 to evaluate the compositions of biomass 28, biochar 32, and inoculant 34. Biomass 28 may undergo physical processing 36. Physical processing 36 may include, but is not limited to, shredding, crushing, grinding, milling, cutting, or a combination thereof. Feed 22 may be mixed with biomass 28, biochar 32, or other “green” or organic matter, and inoculant 34, or a combination thereof, to form a tailings mixture and undergo digestion 38. Water stream 40 or aqueous solution is added to digestion 38. Collected water 42 or solution may be drained from the tailings mixture and may be recycled into digestion 38. The tailings mixture may be subjected to drying 44and undergo QA / QC 46 to evaluate the composition of the tailings mixture. The dry tailings mixture may undergo packaging 48, e.g., bagging, for the produced fertilizer 50. QA / QC 26, 30, and 46 may identify and / or evaluate parameters including, but not limited to, contaminants, particle size, salinity, microbials, and additives.

[0055] For Fig. 1 to Fig. 8, as examples, Table 2 shows the compositions of batches 1 to 5.

[0056] Fig. 3 shows soil organic matter, measured as percent loss on ignition (“% LOI”) for copper porphyry tailings.

[0057] Fig. 4 shows nitrogen forms including total nitrogen, organic nitrogen (“Org. N”), nitrate, and ammonium for the digestion of copper porphyry tailings.

[0058] Fig. 5 shows total phosphorous, inorganic phosphorous, and organic phosphorous for the digestion of copper porphyry tailings.

[0059] Fig. 6 shows micronutrients for the digestion of copper porphyry tailings. Batch micronutrients were unchanged by digestion .

[0060] Figs. 7A and 7B show bacteria and fungi, respectively, for the digestion of copper porphyry tailings.

[0061] Fig. 8 shows soil respiration for the digestion of copper porphyry tailings. Batch soil respiration is greater relative to feedstock.

[0062] Fig. 9 shows pH changes for the digestion of granitic aggregate waste. Batch pH values are lower relative to feedstock.

[0063] Figs. 10A and 10B show organic carbon and CO2 respiration, respectively, for the digestion of granitic aggregate waste. Batch organic carbon and CO2 respiration are greater relative to feedstock.

[0064] Figs. 11 A and 11 B show total and available nitrogen, respectively, for the digestion of granitic aggregate waste. Batch total and available nitrogen are greater relative to feedstock.

[0065] Figs. 12A and 12B show total and available phosphorus respectively, for the digestion of granitic aggregate waste. Batch total and available phosphorus are greater relative to feedstock.

[0066] Fig. 13 shows cation and macronutrient concentrations for the digestion of granitic aggregate waste. Batch iron (“Fe”), manganese (“Mn”), copper (“Cu”) and zinc (“Zn”) are greater relative to feedstock.

[0067] Fig. 14 shows total bacteria and fungi for the digestion of granitic aggregate waste. Batch total bacteria and fungi are greater relative to feedstock.

[0068] Figs. 15A and 15B show organic carbon and CO2 respiration, respectively, for the digestion of lateritic oxide tailings. Batch organic carbon and CO2 respiration are greater relative to feedstock.

[0069] Figs. 16A and 16B show total and available nitrogen, respectively, for the digestion of lateritic oxide tailings. Batch total and available nitrogen is greater relative to feedstock.

[0070] Figs. 17A and 17B show total and available phosphorus, respectively, for the digestion of lateritic oxide tailings. Batch total and available phosphorus is greater relative to feedstock.

[0071] Fig. 18 shows cation and macronutrient concentrations for the digestion of lateritic oxide tailings. Batch cations (potassium, calcium, magnesium) and micronutrients (iron, manganese, copper, zinc) are greater relative to feedstock.

[0072] Fig. 19 shows the total bacteria and fungi for the digestion of lateritic oxide tailings. Batch fungi counts are greater relative to feedstock with the addition of an inoculant.

[0073] The method may comprise using tailings from rock mineral ores that have bio-metals and rock mineral constituents that may be repurposed for their nutrient value to produce fertilizer. The tailings may comprise porphyry copper ore, lead-zinc ore, basaltic ore, ultramafic ore, and iron-rich lateritic ore, other mineral ore, or a combination thereof.

[0074] The tailings may comprise a rock-type having an enrichment of metals including but not limited to, copper, with a metal grade suitable for economic production levels and commercial sale. The tailings may comprise an igneous deposit including, but not limited to, granites, andesites, quartz monzonites, granodiorites, diorites, or a combination thereof. The tailings may comprise a rock-type defined chemical and mineral composition that has resulted from sequences of intrusion, alteration, and other hydrothermal phases during their formation. The rock-type may comprise a feldspar and / or quartz mineralogy. The feldspars may release nutrients including, but not limited to, potassium, sodium, calcium, another element, or a combination thereof. These nutrients may be within the mineral framework of the tailings and may be released through the biological interaction with plant roots and soil microbes, i.e. , digestion. The rock-type may comprise micas. The micas may release potassium that is more readily available to plants in an exchangeable form following digestion.

[0075] The rock type may comprise a calc-alkaline and / or alkaline type-deposit. The rock-type may be identified and / or evaluated by the ratios of sodium and potassium to magnesium and iron in the rock. The rock type may comprise a mineral deposit linked spatially to mineralization features including, but not limited to, skarns, polymetallic veins and replacements, epithermal veins, or a combination thereof.

[0076] This tailings may comprise a fine-grained material. At least a portion of the tailings may be at a size of less than about 50 micrometers (“pm”), about 50 pm to about 5m, about 45 pm to about 10 pm, about 40 pm to about 15 pm, about 35 pm to about 20 pm, about 30 pm to about 25 pm, or about 5 pm in diameter.

[0077] The biomass may provide nitrogen and / or carbon for microbial activity during the digestion. The biomass may comprise green material. The green material may comprise simple sugars with a carbon to nitrogen (“C:N”) ratio of about 30:1. The green material may comprise food and agricultural waste including, but not limited to, peppers, chiles, grape pomace, lettuce, potatoes, onions, sugar beets, other tubers, or a combination thereof. The biomass may comprise high-nitrogen material. The high-nitrogen material may comprise a C:N ratio of about 10:1. The high-nitrogen material may include, but is not limited to, alfalfa, coffee grounds, coffee waste, waste hay, haylage, legumes, manures, seeds, shells, meat, blood, or a combination thereof. The biomass may comprise a woody-browns material. The woody-browns material may comprise a C:N ratio of more than 60:1. The woody-browns material may include, but is not limited to, tree shrubs including but not limited to juniper shrubs, woodland shrubs, cotton stalks, corn stalks, other shrubs and stalks, needles including but not limited to pine needles, grass, garden clippings, paper, or a combination thereof.

[0078] This biomass may be physically processed. Physical processing may comprise crushing, shredding, beneficiation, comminuting, or a combination thereof. Physical processing may occur before the biomass is digested. The biomass physical processing may enable successful chemical reactions. The biomass may be physically processed to a diameter of less than about 5 millimeters (“mm”), about 5 mm to about 0.1 mm, about 4 mm to about 0.5 mm, about 3 mm to about 1 mm, or about 0.1 mm in diameter. The biomass may be mixed with the tailings and / or biochar after physically processing.

[0079] The method may comprise mixing the tailings with biochar. The biochar, a stable carbon-rich product with high surface area and functional groups, may facilitate water retention, pH adjustment, nutrient retention, and water filtration, soil microbes enhancement, or a combination thereof.

[0080] The inoculation consortia may comprise microbes and / or microorganisms, which may be naturally occurring, enhanced or added to the mixture. The microbes and / or microorganisms may include, but are not limited to, a bacterium, a fungus, a cyanobacteria or a combination thereof. The inoculation consortia may comprise one or more of a plurality of bacteria and / or fungal species. The microbes and / or microorganisms may include but are not limited to, fungal and / or bacterial phylum. The fungal phylum may include, but is not limited to, Ascomycota, Basidiomycota, Mucoromycota, or a combination thereof. The bacteria phylum may include, but is not limited to, Proteobacteria, Actinobacteriota, Bacteroidota, Myxococcota, Deinococcota, or a combination thereof.

[0081] The inoculation consortia may comprise one or more of a plurality of microbes and / or microorganisms or a single strain inoculant. The inoculation consortia may provide greater resilience to stress and to improve the ability of the microbes and / or microorganisms to survive competition from resident microorganisms compared to a singlestrain inoculant. The inoculation consortia may allow the microbes and / or microorganisms to persist and perform their intended functions and allow for a greater breadth of ecological functions to be added to the soil microbiome.

[0082] The inoculation consortia may comprise microbes and / or microorganisms from the soil environment in which community members have naturally evolved and interact with each other. The inoculation consortia may access a mineral nutrient within the tailings and / or tailings mixture. This microbes and / or microorganisms may develop naturally, where they are more likely to represent native interactions, driven primarily by microbial ecology to promote plant growth and resilience for specific regions and crops, and to respond to climate change and stress conditions.

[0083] The method may comprise mixing the biomass, biochar, tailings, inoculant, and / or tailings mixture. Mixing may be performed by windrows either manually or with a compost turner. Mixing may be mechanized and / or automated.

[0084] The tailings mixture may comprise at least about 50%, about 50% to about 80%, about 55% to about 75%, about 60% to about 70%, or about 80% tailings by weight. The tailings mixture may comprise at least about 4%, about 4% to about 16%, about 6% to about 14%, about 8% to about 10% green waste by weight. The tailings mixture maycomprise at least about 1 %, about 1% to about 10%, about 2% to about 9%, about 3% to about 8%, about 4% to about 7%, about 5% to about 6%, or about 10% high-nitrogen material by weight. The tailings mixture may comprise at least about 20%, about 20% to about 50%, about 25% to about 45%, about 30% to about 40%, or about 50% biomass or biochar by weight.

[0085] The method may comprise physically turnings of the tailings mixture to provide fresh oxygen, reduce heat levels, and maintain aerobic conditions. Aerobic conditions enable the chemical reactions and physical transformations to convert the tailings mixture into a fertilizer. Manual mixing or windrow turners may be used to physically turn the tailings mixture. The windrow turner may comprise angled teeth attached to cylinders that turn, pulling from the sides to the middle, the middle is thrown up into the air and the sides slip down from the top of the pile to the sides. All material enters the center of the blend after two turns for digestion periods. Following the second turn, the windrow may be allowed to meet ambient temperatures and no added moisture during this period.

[0086] The digestion may comprise monitoring and assessing digestion progression and identifying corrective action, dictate mixing conditions, or a combination thereof.

[0087] The tailings mixture may be at temperature of at least about 50 °C, about 50 °C to about 80 °C, about 55 °C to about 75 °C, about 60 °C to about 70 °C, or about 80 °C. Digestion may occur in a plurality of phases. Digestion may comprise a thermophilic phase that allows the breakdown of organic materials and the reduction of pathogens. Increased temperature results from the rapid growth of microbes decomposing the organic matter in the windrow. Digestion may comprise phases one, two, and three. The temperature for phase one may be about 40 °C to about 65 °C and may last for up to 72 hours. The temperature for phase two may be about 50 °C to about 75 °C and may last for up to 48 hours. The temperature for phase two may be about 65 °C to about 80 °C and may last for up to 24 hours.

[0088] The method may comprise monitoring the temperature of the tailings mixture. The middle of the tailings mixture may be higher than the edges of the tailings mixture. The temperature in the tailings mixture may be tracked after the tailings mixturemoves into a higher temperature range. If temperatures exceed about 80 °C or other temperature depending on the conditions, an outlet (e.g., a chimney) may be disposed into the tailings mixture to keep an open channel to the surface to maintain aerobic conditions and prevent temperatures increasing further. If the tailings mixture temperature reaches the temperature, the tailings mixture may be turned to avoid development of anerobic conditions and avoid fire risk. The tailings mixture may then be allowed to return to ambient or lower temperatures.

[0089] The water content and / or moisture content of the tailing mixture may be at least about 40%, about 40% to about 70%, about 45% to about 65%, about 50% to about 60%, or about 70%. The water content and / or moisture content may maintain aerobic conditions and / or minimizing runoff from the tailings mixture. The edges of the tailings mixture may be drier than the interior of the tailings mixture.

[0090] The aqueous solution and / or water added to the tailings mixture during digestion may be non-saline or saline. The aqueous solution and / or water may comprise a specific conductance less than about 2 deci-Seimens per meter (“dS / m”), about 2 dS / m to about 0 dS / m, about 1.5 dS / m to about 0.5 dS / m, or about 0 dS / m. The aqueous solution and / or water may comprise no chlorine.

[0091] The method may comprise monitoring odors and / or gases emitted from the tailings mixture. Monitoring may comprise detecting gases including, but not limited to, e.g., methane (“CH4”), hydrogen sulfide (“H2S”) (to detect anerobic conditions), carbon dioxide (“CO2”) (to detect carbon loss during digestion), or a combination thereof. The gas may be monitored at a frequency needed, e.g., daily. The method may comprise disposing an outlet (e.g., a chimney) into the tailings mixture to return and / or maintain aerobic conditions in the tailings mixture, or to turn the tailings mixture. After aerobic conditions are reestablished, the method may comprise allowing the tailings mixture to be at ambient or lower temperatures for a period of time, e.g., days, or a week without added moisture.

[0092] The tailings mixture may be at a pH of at least about 5, about 5 to about 8.5, about 5.5 to about 8, about 6 to about 7.5, or about 8.5.

[0093] The digestion may comprise an oxidation reaction. The oxidation reaction occurring in the digestion process may be driven by a microbe and / or microorganism. Thedigestion may comprise microbial decomposition. Microbial decomposition may occur where microorganisms including but not limited to bacteria, fungi, and actinomycetes break down organic materials. The process may be categorized into three phases: the mesophilic phase, the thermophilic phase, and the cooling and maturation phase. In the mesophilic phase, mesophilic microorganisms thrive in moderate temperatures (e.g., about 20 °C to about 40 °C) and start breaking down the easily degradable components of the waste, such as sugars and starches. In the thermophilic phase, as the activity of microorganisms increases, the temperature of the mixture or pile rises, favoring thermophilic microorganisms. These microorganisms decompose more complex molecules including but not limited to proteins, fats, and cellulose, at temperatures between e.g., about 40 °C to about 60 °C. In the cooling and maturation phase, after the peak of thermophilic activity, the mixture or pile cools down, and mesophilic organisms once again become dominant, helping further in the breakdown of remaining materials and stabilizing the mixture or pile.

[0094] The method may comprise a chemical breakdown. The chemical breakdown may occur where organic materials undergo oxidation as part of microbial respiration. This process converts organic carbon to carbon dioxide and enables the release of nutrients in forms that plants can more easily absorb. The method may comprise a physical change. The physical change may occur where the physical structure of the materials changes as well, with particles becoming smaller and more homogenized due to microbial activity and the breakdown of fibrous materials.

[0095] The method may comprise a biochemical transformation. The biochemical transformation may occur where biochemical reactions occur, including the breakdown of lignin, cellulose, and hemicellulose into simpler compounds. Enzymatic reactions may transform nitrogenous compounds into ammonium and then into nitrates through the process of nitrification. The biochemical transformation may occur during digestion.

[0096] The method may comprise humification. Humification may occur after the active decomposition phases, and the material undergoes humification where it transforms into humus, a stable, nutrient-rich material. Humus improves soil structure, moisture retention, and provides nutrients to plants. Humification may occur during digestion.

[0097] The method may comprise nitrification and / or mineralization. Ammonia released by the decomposition of nitrogenous organic matter is oxidized to nitrites and then to nitrates by nitrifying bacteria, known as nitrification. Mineralization comprises the conversion of organic forms of nutrients to inorganic forms, making them available for plant uptake. Nitrification and / or mineralization occur during digestion.

[0098] The method may comprise transforming organic materials into a stable, nutrient-rich compost that may be used to enhance soil fertility and structure via use of an aerobic. The general equation for the aerobic digestion may be written as Equation (1):Organic Matter + O2— > CO2+ H2O + Energy (1)

[0099] More specifically, for carbohydrates (including but not limited to sugars and starches, which comprise carbon, hydrogen, and oxygen), the equation may be represented as Equation (2):C6HI2O6+ 6O26CO2+ H2O (2)

[0100] Equation 2 shows the breakdown of glucose, a simple sugar, which is a common component of decaying plant matter.

[0101] For fats (comprising mainly of triglycerides, which are esters of glycerol and fatty acids), the breakdown may be represented as Equation (3):C57H104O6 + 80O257 CO2+ 52H2O (3)

[0102] Equation 3 is a simplified representation for the oxidation of a typical triglyceride molecule. For proteins (which contain nitrogen in addition to carbon, hydrogen, and oxygen), the decomposition may be more complex due to nitrogen transformation, as shown in Equation 4:C5H7NO2+ 5O25CO2+ 2H2O + NH3(4)

[0103] Equation 4 is a simplified example for the oxidative breakdown of a basic amino acid, releasing ammonia in addition to carbon dioxide and water.

[0104] The digestion process may allow microbes to facilitate the breakdown of minerals and release of plant available nutrients. This process involves chemical reactions involving organic acids and other metabolites produced by the microbes. The dominate reactions may comprise acidolysis by an organic acid and / or a hydrolysis reaction. In acidolysis by an organic acid, an organic acids such as citric acid and oxalic acid produced by microbes may dissolve minerals including, but not limited to, silicates and / or carbonates. An example is the dissolving of silicate minerals according to Equation (5).KAISi3O8+ 2H++ H2O K++ AISi2O5(OH)4+ 2SiO2(5)

[0105] In Equation 5, potassium feldspar (KAISi3O8) breaks down into kaolinite (AI2Si2Os(OH)4), silica (SiO2), and potassium ions (K+), facilitated by hydrogen ions (H+) typically derived from a microbial organic acid.

[0106] In a hydrolysis reaction, microbial production of acids may lead to direct hydrolysis of minerals according to Equation (6).CaSiO3+2H+Ca2++ SiO2+ H2O (6)

[0107] In Equation 6, Wollastonite CaSiO3is broken into calcium ions, silica and water facilitated by hydrogen ions (H+) derived from a microbial organic acid.

[0108] The tailings mixture may comprise an electrical conductivity (“EC”). The electrical conductivity may be an indicator of the salt content in the tailings mixture. High levels of salts may be toxic to plants and microorganisms. The EC may be less than about 2 deci-Seimens per meter (“dS / m”), about 2 dS / m to about 0 dS / m, about 1.5 dS / m to about 0.5 dS / m, or about 0 dS / m.

[0109] The method may comprise at least partially disposing a liner below the tailings mixture. The tailings mixture may be digested for a period of days, or months, including but not limited to at least about 15 days, about 15 days to about 30 days, about 20 days to about 25 days, or about 30 days.

[0110] The method may comprise monitoring of water content during digestion to about 40% to about 60% or about 45% to about 55%, to prevent leaching and runoff fromthe tailings material. The method may comprise adding an aqueous solution and / or water to the tailings mixture to provide additional control to the temperature levels in the piles and ensure appropriate moisture levels to maintain microbial reactions.

[0111] Following completion of aerobic digestion, the fertilizer may be collected and / or transported to a storage area.

[0112] This method may comprise maturing, storing, and / or transporting the fertilizer after the fertilizer has been dried. The method may comprise measuring the fertilizer quality. The quality of the fertilizer may be measured by determining total nitrogen; available phosphoric acid (P2O5); soluble potash (K2O) expressed as a weight percentage; the percent weight of secondary nutrients including, but not limited to, calcium, magnesium, sulfate, iron, other metals or minerals, or a combination thereof; the level of micronutrients including, but not limited to, copper, zinc, iron, manganese, boron, or a combination thereof; the salt content (as a sodium and chloride weight percentage); the electrical conductivity; the pH; organic matter; organic carbon; moisture content; bulk density; or a combination thereof.

[0113] The quality of the fertilizer may be measured by characterizing the metal content. The metal content may be characterized by determining total metals (such as by Aqua Regia digestion or inductively coupled plasma analysis); mercury content (such as by direct combustion atomic absorption, or a combination thereof. The metal content may also be characterized by determining the presence and amount of the metals, including but not limited to, aluminum, antimony, arsenic, barium, beryllium, cadmium, chromium, cobalt, copper, iron, lead, lithium, manganese, molybdenum, nickel, selenium, silver, thallium, tin, vanadium, zinc, or a combination thereof. The metal content may also be characterized by determining the presence and amount of leachable metals (such as by synthetic precipitation leachate potential) including, but not limited to, aluminum, arsenic, boron, cadmium, cobalt, copper, lead, manganese, mercury, molybdenum, selenium, silver, zinc, or a combination thereof.

[0114] Embodiments of the present invention provide a technology-based solution that overcomes existing problems with the current state of the art in a technical way to satisfy an existing problem for mining operators or mineral processing facilities with oreand / or tailings deposits. Embodiments of the present invention achieve important benefits over the current state of the art, such as a method of converting mining waste material, e.g., tailings, into a usable product, e.g., fertilizer. Some of the unconventional steps of embodiments of the present invention include converting mineral tailings to fertilizer by mixing the tailings with biomass and an inoculant under aerobic conditions.Industrial Applicability:

[0115] The invention is further illustrated by the following non-limiting examples.Example 1

[0116] Fertilizer was produced from tailings from skarn-porphyry ore. Tailings material produced from skarn-rich, copper-zinc porphyry ore was prepared into batches. The tailings comprised 45% weight / weight tailings / supernatant. Initial testing undertaken with the as received material and food waste as biomass reported elevated soluble salt within the solid fertilizer product, with the salts dominated by calcium. The excess water from both the supernatant and the food waste (93% moisture content) was decanted and tested for suitability as a liquid fertilizer. The soluble salt content of the decanted liquid was again dominated by calcium.

[0117] Additional test work was undertaken with dewatered tailings. Primary test work involved processing three different tailings with three waste biomass sources with different characteristics - food waste, agricultural waste potatoes, and composted cattle manure. Other inputs included microbial inoculants and biochar. The feedstocks were blended under aerobic conditions and analyzed for general chemistry, nutrients, and metals. The resultant blends produced a broad-spectrum nutrient fertilizer with the potential for agronomic benefit, soil health and climate change. Testing during this phase of work indicates no significant environmental impact from residual metals in the tailings. The results of this testing indicated that the dewatered porphyry copper tailings provided for testing were suitable for feedstock as a biomineral fertilizer.Example 2

[0118] Fertilizer was produced from tailings from skarn-porphyry ore. Tailings material produced from skarn-rich, copper-zinc porphyry ore was prepared into batches. Processing of mine wastes was undertaken with various biomass feedstocks, including coffee cherries and food waste. Six batches were each processed for approximately three weeks. Adequate available major nutrients (nitrogen, phosphorus, potassium), secondary nutrients (calcium, magnesium, iron, sulfur) and micronutrients (chromium, copper, manganese, molybdenum, zinc) were suitable for plant growth. Soluble nutrients included potassium, calcium, magnesium, sodium, sulfur, copper, manganese and molybdenum. Copper and zinc were in concentrations suitable for biofortification of foods grown in soils amended with these biomineral fertilizers. Most metals that were identified during feedstock characterization (e.g., arsenic, selenium) were not identified as exceeding the proposed standards following processing. Pathogens were not detected in any of the finished products indicating that the processing method is suitable for removing any potential pathogens introduced by the biomass. Overall nutritional quality was driven more by the mineral feedstock (tailings) than the biomass.Table 3: Feedstock Mixture for Biominera Fertilizer Processing, Skarn Porphyry Tailings

[0119] The results of the testing performed with different compositions or tailings, biomass and biochar provided optimum thresholds or ranges for the individual components to contribute to the production of the fertilizer. Further, the testing reconfirmed the suitability of porphyry copper rock material, with the required particle size and metals content described herein, for the production of a product having the compositional and nutritional value required for a fertilizer.Example 3

[0120] Fertilizer was produced from tailings from porphyry ore. Four batches of copper porphyry tailings were prepared, using different types of biomass. The processing conditions, soil chemistry, and microbiology were closely monitored and analyzed. The addition of biomass improved soil organic carbon and nitrogen content. Phosphorus was predominantly inorganic and plant available. Potassium was low but expected to become available in agricultural settings. Micronutrients were adequate, with no change based on biodigestion. The biomass addition enhanced the microbial biome, with a notable presence of beneficial phyla including but not limited to Actinobacteriota, Proteobacteria, Bacteroidota, and Mucoromycota. However, overall microbial diversity was low. The formulations developed a neutral pH and acceptable electrical conductivity for agricultural applications. Soil respiration and carbon turnover were high, indicating active microbial processes. A formulation comprising tailings mixed with food waste, high nitrogen, and woody / biochar with inoculant, emerged as the most suitable formulation for biomineral fertilizer production.Table 4: Feedstock Mineralogy, Copper Porphyry TailingsExample 4

[0121] Fertilizer was produced from granitic aggregate waste._ Granitic aggregate waste was prepared by sieving to < 2 mm and combined with zeolite to produce a feedstock of the following proportion: granite (80% vol / vol), zeolite (20% vol / vol). Testing prepared 3,000 mL batches of 1 ,500 mL tailings and 1 ,500 mL of organic material consistingof 375 mL high nitrogen material (cracked corn), 450 mL green material (food waste) and 675 mL of brown material (270 mL mature compost; 135 mL wood chips; 135 mL biochar; 135 mL humic acid). Two batches were prepared with one having an inoculant added. Following digestion, pH was reduced from alkaline in the feedstock to circumneutral in the batches. Organic carbon and microbial respiration both increased following digestion as well as total and available nitrogen and phosphorus. Micronutrients (iron, copper, zinc) were improved. Biodigestion improved counts of both bacteria and fungi.

[0122] The results of the testing performed on tailings material from different ore sources having a greater variability for a single phase of testing and having different composition than the previous test work, reconfirmed the viability to use mine tailings with different compositions in the production of a product having the compositional and nutritional value required for a bio-mineral fertilizer.Example 5

[0123] Fertilizer was produced from lateritic oxide tailings. Feedstock characterization indicated the following: the mineralogy was dominated by iron, manganese and aluminum oxides; the total metals were dominated by iron, manganese and aluminum; the leachable metals shows very low release of elements as predicted by highly resistant minerals; the soil chemistry indicated circumneutral, low salts, and low nutrients; the plant available nutrients shows low macronutrients and acceptable micronutrients; and the microbiology shows bacteria dominated system with good diversity. Microbe species of interest for development into a biomineral fertilizer included nitrogen fixing bacteria, phosphorus and potassium solubilizing bacteria, and metal resistant bacteria and fungi.

[0124] Testing was prepared from 3,000 mL batches of 1 ,500 mL tailings and 1 ,500 mL of organic material consisting of 375 mL high nitrogen material (cracked corn), 450 mL green material (food waste) and 675 mL of brown material (270 mL mature compost; 135 mL wood chips; 135 mL biochar; 135 mL humic acid). Two batches were prepared, with one having an inoculant added. Organic carbon and microbial respiration both increased following digestion as well as total and available nitrogen and phosphorus. Available cations (potassium, calcium, magnesium) and micronutrients (iron, manganese, copper, zinc) wereimproved by biodigestion. Biodigestion improved counts of fungi with the addition of an inoculant.

[0125] The preceding examples can be repeated with similar success by substituting the generically or specifically described reactants and / or operating conditions of this invention for those used in the preceding examples.

[0126] Note that in the specification and claims, “about” or “approximately” means within twenty percent (20%) of the numerical amount cited. The terms, “a”, “an”, “the”, and “said” mean “one or more” unless context explicitly dictates otherwise.

[0127] Although the invention has been described in detail with particular reference to these embodiments, other embodiments can achieve the same results. Variations and modifications of the present invention will be obvious to those skilled in the art and it is intended to cover in the appended claims all such modifications and equivalents. The entire disclosures of all references, applications, patents, and publications cited above are hereby incorporated by reference.

Claims

CLAIMS1. A method of fertilizer production, the method comprising: contacting a tailings material with biomass and an inoculation consortia to form a tailings mixture; mixing the tailings mixture; contacting the tailings mixture with a solution; aerobically digesting the tailings mixture; and drying the tailings mixture to form fertilizer.

2. The method of claim 1 wherein mixing comprises manual mixing.

3. The method of claim 1 wherein mixing comprises windrow turning.

4. The method of claim 1 wherein the biomass comprises a biomass green material.

5. The method of claim 1 wherein the biomass comprises a high nitrogen material.

6. The method of claim 1 wherein the biomass comprises a woody-browns material.

7. The method of claim 1 further comprising contacting the tailings material with biochar.

8. The method of claim 1 wherein the biomass comprises a carbon to nitrogen ratio of at least about 10:1.

9. The method of claim 1 wherein the tailings material comprises porphyry ore or tailings.

10. The method of claim 1 wherein the tailings material comprises granitic aggregate.

11. The method of claim 1 wherein the tailings material comprises lateritic oxide tailings.

12. The method of claim 1 wherein the inoculation consortia comprises a bacterium.

13. The method of claim 1 wherein the inoculation consortia comprises a fungi.

14. The method of claim 1 wherein the solution is non-saline.

15. The method of claim 1 wherein the solution is an aqueous solution or water.

16. The method of claim 1 wherein the tailings mixture is about 50% to about 80% tailings material by weight.

17. The method of claim 1 wherein the tailings material comprises a macronutrient.

18. The method of claim 1 wherein the tailings material comprises a micronutrient.

19. A fertilizer composition, the fertilizer composition comprising: a tailings material; the tailings material comprising a macronutrient; the tailings material comprising a micronutrient; a biomass; and inoculation consortia.

20. The fertilizer composition of claim 19 wherein the mineral tailings comprise ore or tailings.

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