Phosphate collector composition

Abstract

The disclosure includes an aqueous collector composition which includes (a) at least 15 wt% up to about 70 wt%, preferably no more than about 60 wt%, more preferably no more than about 50 wt%, further preferably no more than about 40 wt%, even more preferably no more than about 30 wt% of a fatty acid, fatty acid ester, its salt or any combinations thereof, preferably the fatty acid, fatty acid ester and / or its salt comprises a non-sulfonated fatty acid, fatty acid ester and / or its salt; and (b) up to about 25 wt%, preferably up to about 20 wt%, further preferably up to about 15 wt%, more preferably at least about 2 wt%, even more preferably at least about 3 wt% of a hydrotrope, preferably the hydrotrope comprises an organic group chemically bonded to a polar group, preferably the polar group comprises at least one of a carboxylate, a phosphate, a phosphonate, a sulfate, a sulfonate, its salt form and combinations thereof, still preferably the hydrotrope comprises an alk(en)yl aryl sulfonate, more preferably an alkyl benzene sulfonate, even more preferably the alk(en)yl benzene sulfonate comprises at least one of dodecylbenzene sulfonate, petroleum sulfonate and combinations thereof, further preferably the hydrotrope comprises one selected from the group of sodium hexanoate, sodium octanoate, dodecylbenzene sulfonate, petroleum sulfonate and combinations thereof. Preferably a pH of the aqueous collector composition comprises more than 7.0, preferably more than about 8.0, further preferably less than about 13.0.

Description

[0001] PHOSPHATE COLLECTOR COMPOSITION

[0002] FIELD OF THE INVENTION

[0003] This invention relates generally to a collector composition (may also be referred to as a "collector") for beneficiating phosphate ores. The collector composition may have applications regarding other agriculture and / or industrial minerals. The collector is also suitable for the selective flotation (aka froth flotation) and separation of predetermined minerals.

[0004] BACKGROUND

[0005] The growing world population constantly imposes an increasingly high demand on fertilizers, of which phosphate is a critical ingredient. The efficient beneficiation of phosphate ores is thus crucial in meeting the high fertilizer demand to feed the world. Since the high-quality siliceous phosphate resources is limited, it is essential for the phosphate industry to mine low-grade phosphate ores with high impurity. Common impurities that co-exist with the phosphate in ore are silica sand, clays, calcium and magnesium carbonates, iron minerals, etc. Among the impurities, silica sand and clays are considered as the most problematic because phosphate grade is getting lower with decades of operation. According to a commonly used process, the incoming mineral feed must be exposed to some means of size fraction control, where clays and oversized fractions are removed, as well as possibly generating different sized flotation feeds. Two flotation processes are often required: the flotation of phosphate with an anionic type collector, followed by a process where the remaining undesired silica minerals are floated away from a rougher phosphate concentrate product with an amine collector to a targeted grade. The most used collectors, such as fatty acids and their derivatives, are thought to be effective collectors for oxidized mineral ores. However, selectivity, and thus the grade of the desired minerals in the concentrates, is a major challenge associated with the recovery of alkaline flotation.

[0006] The most widely adopted technique in beneficiating phosphate ores is froth flotation, whose efficiency largely depends on the ability of the flotation collectors to differentiate the surface hydrophobicity of the valuable minerals and the unwanted impurities in the ore.

[0007] In US10434520, a collector composition for the beneficiation of phosphate ores containing high carbonate impurities is disclosed. The collector comprised of fatty acids, sulfonate or sulfate groups comprising dodecylbenzene sulfonic acid or its salt, and phosphorous-bearing inorganic acid or its salt. The use of alkoxylated alcohols as secondary collector or emulsifier to boost the flotation efficiency of fatty acids containing collectors is also known in the prior art. US4789466 taught the use of ethylene oxide and propylene oxide with a C8-C22 fatty alcohol together with at least one anionic, cationic, or amphoteric surfactant for separating non-sulfidic ores.

[0008] US10376901 taught the use of branched C12-C16 fatty alcohol alkoxylates with a degree of ethoxylation of up to three as a secondary collector for phosphate beneficiation. The primary collector was selected from the group of amphoteric and anionic surface-active compounds. The anionic surfactants consisted of fatty acids, sulfonates, alkyl phosphates, and alkyl sulfates.

[0009] WO2018197476A1 claimed that the alkoxylated branched alcohols with a degree of alkoxylation from 0.1 to 15 and another alkoxylated branched alcohol with a degree of alkoxylation from 1 to 30 can be used in combination with fatty acids or their derivatives for the beneficiation of phosphate containing ores.

[0010] W02020083793A1 used alkoxylated C9-C18 alcohols with a degree of ethoxylation from 2 to 10 and a degree of propoxylation from 1 to 10 to improve the efficiency of fatty acid collector in phosphate flotation. The alkoxylated alcohol can be linear or branched. The publication also disclosed another alkoxylated branched alcohol can be used.

[0011] WO2017162563A2 disclosed a secondary collector for the froth flotation of non-sulfidic ores. The secondary collector is a mixture of branched C12-C16 fatty alcohol with a degree of ethoxylation up to 4 and an alkoxylated nonionic hydrocarbon with a degree of ethoxylation higher than 3. The alkoxylated nonionic hydrocarbon can be C8-C24 linear or branched alcohols with an ethoxylation from 4 to 30. The primary collector to be used with the secondary collector can be selected from the group of amphoteric and anionic surface-active compounds.

[0012] BRIEF DESCRIPTION

[0013] The below embodiments and others of the present disclosure will become apparent in light of the following disclosure.

[0014] An embodiment disclosed herein is a, preferably aqueous, collector composition, preferably a phosphate collector composition. The collector composition may comprise at least about 10 wt% up to about 70 wt%, preferably no more than about 60 wt%, preferably no more than about 50 wt%, preferably no more than about 40 wt%, preferably no more than about 30 wt%, more preferably at least about 20 wt%, of a fatty acid, fatty acid ester or its salt. Preferably the fatty acid, fatty acid ester or its salt comprises a non-sulfonated fatty acid fatty acid ester or its salt. The collector composition may comprise up to about 10 wt%, more preferably at least about 2 wt%, of an alcohol ether sulfate.

[0015] Further the collector composition may include up to about 10 wt%, preferably up to about 5 wt%, more preferably up to about 4 wt%, further preferably up to about 2 wt%, even more preferably at least about 0.5 wt% of a sulfonated fatty acid or its salt. Preferably the sulfonated fatty acid or its salt comprises a fatty acid other than tall oil fatty acid, more preferably the sulfonated fatty acid or its salt comprises a fatty acid other than the tall oil fatty acid and / or a coconut fatty acid, further preferably the sulfonated fatty acid or its salt comprises no more than about 0.1 wt% of both the tall oil fatty acid and the coconut fatty acid, even more preferably less than about 0.05 wt% of the tall oil fatty acid and the coconut fatty acid.

[0016] Additionally the collector composition may include up to about 25 wt%, preferably up to about 20 wt%, more preferably up to about 15 wt%, further preferably up to about 10 wt%, even further preferably up to about 5 wt%, still more preferably at least about 0.5 wt%, at east about 1 wt%, at least about 2 wt%, still further preferably at least about 3 wt% of a hydrotrope, preferably the hydrotrope comprises a carboxylate, a phosphate, a phosphonate, a sulfate or a sulfonate, more preferably the hydrotrope comprises at least one of an alk(en)yl aryl sulfonate or a straight chain fatty acid salt, still more preferably the alk(en)yl aryl sulfonate comprises an alkyl benzene sulfonate, even more preferably the alkyl benzene sulfonate comprises dodecylbenzene sulfonate, further preferably the hydrotrope comprises one selected from the group of sodium hexanoate, sodium octanoic, dodecylbenzene sulfonate, petroleum sulfonate and combinations thereof .

[0017] It is preferred the collector composition has a pH of more than 7.0, preferably more than about 8.0, further preferably more than about 8.5, more preferably more than about 9.0. even more preferably at least about 9.5, even further preferably at least about 10, and most preferably less than about 13.0. In another embodiment, the invention relates to a flotation method for separating impurities from phosphate ores, the method comprising: producing an ore slurry comprising phosphate ore and the collector described above; and subjecting the ore slurry to flotation. The ore slurry may further comprise water such that the ore slurry has about 20 wt% to 85 wt% solids, preferably at least about 30wt% of solids, more preferably at least about 40wt% of solids, even more preferably at least about 50wt% of solids, further preferably at least about 60wt% of solids, even further preferably at least about 65wt% of solids prior to introducing the collector. The ore slurry may not comprise a separate phosphate depressant. Subjecting the ore slurry to flotation may produce an underflow and an overflow. The method may further comprise separating the overflow as a phosphate concentrate and collecting the overflow and the underflow is processed as a tail.

[0018] Embodiments of the collector composition have exhibited an increased amount of phosphorous material in the concentrate, additionally preferably less of the phosphorous material in the tail. Further embodiments disclosed herein have exhibited a higher grade of phosphorus material, e.g., P2O5, in the concentrate than conventional collector compositions.

[0019] Advantages of the claimed subject matter includes the disclosure of embodiments of compositions having an appropriate viscosity to function as a collector composition, e.g., compositions having a viscosity of less than about 5000 cP at a given temperature, preferably less than about 3000 cP at a given temperature, more preferably less than about 2000 cP at a given temperature, further preferably less than about 1000 cP at a given temperature,. An exemplary but non-limiting embodiment of the given temperature may be from about 50°F to about 70°F.

[0020] DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a chart of the percent recovery of phosphate vs. the dosage for the claimed collector composition and a control used for the beneficiation.

[0022] Figure 2 is a chart of showing the effect of the claimed collector composition that includes a viscosity reducing agent.

[0023] DETAILED DESCRIPTION The description herein is merely illustrative of specific manners in which to make and use this invention and are not to be interpreted as limiting in scope. In addition, it is understood that the phraseology and terminology employed herein is for the purpose of description and should not be regarded as limiting. Unless otherwise defined herein, technical terms used in connection with the present disclosure shall have the meanings that are commonly understood by those of ordinary skill in the art. Further, unless otherwise required by context, singular terms shall include pluralities and plural terms shall include the singular.

[0024] All patents, published patent applications, and non-patent publications mentioned in the specification are indicative of the level of skill of those skilled in the art to which the present disclosure pertains. All patents, published patent applications, and non-patent publications referenced in any portion of this application are herein expressly incorporated by reference in their entirety to the same extent as if each individual patent or publication was specifically and individually indicated to be incorporated by reference.

[0025] All of the articles and / or methods disclosed herein can be made and executed without undue experimentation in light of the present disclosure. While the articles and methods of the present disclosure have been described in terms of preferred embodiments, it will be apparent to those of ordinary skill in the art that variations can be applied to the articles and / or methods and in the steps or in the sequence of steps of the method(s) described herein without departing from the concept, spirit and scope of the present disclosure. All such similar substitutes and modifications apparent to those skilled in the art are deemed to be within the spirit, scope and concept of the present disclosure.

[0026] While the collector compositions have been described with a certain degree of particularity, it is to be noted that many modifications may be made in the details of the components without departing from the spirit and scope of this disclosure. It is understood that the compositions are not limited to the embodiments set forth herein for purposes of exemplification.

[0027] The term "at least one" refers to one as well as any quantity more than one, including but not limited to, 1, 2, 3, 4, 5, 10, 15, 20, 30, 40, 50, 100, etc. The term "at least one" can extend up to 100 or 1000 or more depending on the term to which it is attached.

[0028] All percentages, parts, proportions, and ratios as used herein are by weight of the total composition, unless otherwise specified. All such weights as they pertain to listed ingredients are based on the active level and therefore do not include solvents or by-products that can be included in commercially available materials, unless otherwise specified. For example the wt% recited herein is a wt% based on the entire collector composition unless otherwise stated herein.

[0029] All references to singular characteristics or limitations of the present invention shall include the corresponding plural characteristics or limitations, and vice-versa, unless otherwise specified or clearly implied to the contrary by the context in which the reference is made.

[0030] Numerical ranges as used herein are intended to include every number and subset of numbers contained within that range, whether specifically disclosed or not. Further, these numerical ranges should be construed as providing support for a claim directed to any number or subset of numbers in that range. As used herein, the words "comprising" (and any form of comprising, such as "comprise" and "comprises"), "having" (and any form of having, such as "have" and "has"), "including" (and any form of including, such as "includes" and "include") or "containing" (and any form of containing, such as "contains" and "contain") are inclusive or open-ended and do not exclude additional, unrecited elements or method steps. The terms "or combinations thereof", "and / or combinations thereof" "and combinations thereof", and "combinations thereof" as used herein refer to all permutations and combinations of the listed items preceding the term. For example, "A, B, C, or combinations thereof" is intended to include at least one of: A, B, C, AB, AC, BC, or ABC and, if order is important in a particular context, also BA, CA, CB, CBA, BCA, ACB, BAC, or CAB. Continuing with this example, expressly included are combinations that contain repeats of one or more items or terms, such as BB, AAA, AAB, BBC, AAABCCCC, CBBAAA, CABABB, and so forth. The skilled artisan will understand that typically there is no limit on the number of items or terms in any combination, unless otherwise apparent from the context. For purposes of the following detailed description, other than in any operating examples, or where otherwise indicated, numbers that express, for example, quantities of ingredients used in the specification and claims are to be understood as being modified in all instances by the term "about". The numerical parameters set forth in the specification and attached claims are approximations that can vary depending upon the desired properties to be obtained in carrying out the invention.

[0031] In general, the invention relates to a novel collector (AKA collector composition) for use in a flotation process for the beneficiation of phosphate and alternatively other agriculture or industrial minerals. Preferably the novel collector includes an aqueous composition including (a) at least one fatty acid, fatty acid esters or its salt, preferably a non-sulfonated fatty acid, fatty acid ester or its salt, (b) at least one alcohol ether sulfate, (c) a sulfonated fatty acid or its salt, and (d) a hydrotrope, preferably an alk(en)yl aryl sulfonate. Preferably the collector has a pH of more than 7.0. In particular embodiments, the fatty acid and its salts as well as the sulfonated fatty acid or its salts may be conventional fatty acids, saponified fatty acids and any combination thereof.

[0032] The Fatty Acid

[0033] The composition may include one or more fatty acids, fatty acid esters, or its salts and any combination thereof ("Fatty Acids"). In the case of the fatty acid ester, exemplary compounds may be a fatty acid methyl ester, a fatty acid ethyl ester and combinations thereof. Preferably the one or more Fatty Acid is not sulfonated. Preferably the Fatty Acid may include straight-chain fatty acids, branched chain fatty acids, cycle containing fatty acids, saturated, unsaturated, aromatic containing fatty acids containing from 6 to less than 30 carbon atoms. The Fatty Acid may contain from 6 to 8 carbon atoms, or from 8 to 10 carbon atoms, or from 10 to 12 carbon atoms, or from 12 to 14 carbon atoms, or from 14 to 16 carbon atoms, or from 16 to 18 carbon atoms, or from 18 to 20 carbon atoms, or from 20 to 22 carbon atoms, from 22 to 24 carbon atoms, from 24 carbon atoms to 27 carbon atoms, of from 27 carbon atoms to less than 30 carbon atoms. The Fatty Acid is not limited to a linear compound; it may be nonlinear. Typical sources for the fatty acids may be vegetable or animal fats and oils. Vegetable based fatty acids are a preferred type of fatty acid. Tall oil fatty acid, oleic acid, soya oil fatty acid, palmitic acid, stearic acid, linolenic acid, canola fatty acid and any combination thereof are examples of preferred fatty acids that may be suitable in the collector compositions contemplated herein.

[0034] Preferred amounts of the Fatty Acid in the composition may range from at least about 10 wt% up to about 70 wt%, preferably no more than about 60 wt%, more preferably no more than about 50 wt%, further preferably no more than about 40 wt%, even more preferably no more than about 30 wt%, still further preferably less than 30 wt%, still more preferably at least about 20 wt%, or in the alternative an amount of the Fatty Acid in the collector composition may comprise 15 wt% to about 20 wt%, about 20 wt% to about 25 wt%, about 25 wt% to less than 30 wt%, to 30 wt% to about 35 wt%, about 35 wt% to about 40 wt%, 45wt% to about 50 wt%, about 50 wt% to about 55 wt%, about 55wt% to about 60wt%, about 60 wt% to about 65 wt%, about 65wt% to 70wt% or combinations thereof.

[0035] In an embodiment, an acid number of the particular components that make up the fatty acids may comprise at least about 30 up to about 280. Typical units for the acid number is milligrams of KOH / gram (of test specimen) (e.g., the type of fatty acid: tall oil fatty acid, canola fatty acid, soya fatty acid, oleic acid, etc.). The titration test may be used to determine the acid number. In some embodiments, the fatty acids in the collector composition of the disclosure have an acid number of about 45 to about 280 mg of KOH / g. In particular, the individual fatty acid that make up the Fatty Acid may have an acid number of from about 30 to about 60 mg of KOH / g, about 60 to about 80 mg of KOH / g, about 80 to about 100 mg of KOH / g, about 100 to about 120 mg of KOH / g, about 120 to about 140 mg of KOH / g, about 140 to about 160 mg of KOH / g, about 160 to about 180 mg of KOH / g, about 180 to about 200 mg of KOH / g, about 200 to about 220 mg of KOH / g, about 220 to about 240 mg of KOH / g, about 240 to about 260 mg of KOH / g, about 260 to about 280 mg of KOH / g or combinations thereof.

[0036] Preferably, the Fatty Acid may comprise at least one of soya oil fatty acid, canola fatty acid, tall oil fatty acid, crude tall oil (CTO), distilled tall oil (DTO), oleic acid, esters thereof and any combination thereof, preferably at least 2 selected from the group of the soya oil fatty acid, the canola fatty acid, the oleic acid, the tall oil fatty acid and the esters thereof.

[0037] Optionally, the collector composition may comprise the tall oil fatty acid, its esters and / or its salts. In embodiments disclosed herein the amount of tall oil fatty acid, crude tall oil (CTO), distilled tall oil (DTO), which makes by the Fatty Acid of the collector composition may comprises no more than 95 wt% of the Fatty Acid, preferably less than about 55 wt%, more preferably less than about 20 wt%, further preferably less than about 15 wt%, even more preferably less than about 10 wt%, even further preferred less than about 1 wt%, based on the total amount of the Fatty Acid in the collector composition.

[0038] In some embodiments, the collector composition may comprise the tall oil fatty acid, crude tall oil (CTO), distilled tall oil (DTO), in the amount of about 1 wt% to about 5 wt%, about 5 wt% to about 10 wt%, about 10 wt% to about 15 wt%, about 15 wt% to less than about 20%, about 20 wt% to about 25 wt%, about 25 wt% to about 30 wt%, about 30 wt% to about 35 wt%, about 35 wt% to about 40 wt%, about 40 wt% to about 45 wt%, about 45 wt% to about 50 wt%, about 50 wt% to about 55 wt%, about 55 wt% to about 58 wt%, about 58 wt% to about 61 wt%, about 61 wt% to about 65 wt%, or about 65 wt% to about 70 wt%, or about 70 wt% to about 75 wt%, or about 75 wt% to about 80 wt%, or about 80 wt% to about 85 wt%, or about 85 wt% to about 90 wt%, or about 90 wt% or about 95 wt% or combinations thereof, based on the total amount of the Fatty Acid in the collector composition

[0039] In other embodiments, the collector composition may be devoid of the tall oil fatty acid, its esters and its salts.

[0040] The Fatty Acid in the collector composition may comprise the oleic acid, its esters and / or its salts. The Fatty Acid component of the collector composition may comprise up to about 100 wt% of oleic acid, or suitable amounts such as less than about 95 wt%, less than about 90 wt%, less than about 85 wt%, less than about 80 wt%, less than about 70 wt%, preferably less than about 55 wt%, more preferably less than about 30 wt%, further preferably less than about 15 wt%, even more preferably less than about 10 wt%, even further preferred less than about 1 wt% based on the total amount of the Fatty Acid in the collector composition.

[0041] In some embodiments, the Fatty Acid may comprises the oleic fatty acid in an amount of about 1 wt% to about 5 wt%, about 5 wt% to about 10 wt%, about 10 wt% to about 15 wt%, about 15 wt% to about 19, about 19 wt% to about 23 wt%, about 23 wt% to about 27 wt%, about 27 wt% to about 30 wt%, about 30 wt% to about 35 wt%, about 35 wt% to about 40 wt%, about 40 wt% to about 45 wt%, about 45 wt% to about 50 wt%, about 50 wt% to about 55 wt%, about 55 wt% to about 58 wt%, about 58 wt% to about 61 wt%, about 61 wt% to about 65 wt%, or about 65 wt% to about 70 wt%, about 70 wt% to about 80 wt%, about 80 wt% to about 90 wt%, about 90 wt% to about 100 wt% or combinations thereof based on the total amount of the Fatty Acid in the collector composition.

[0042] The Fatty Acid in the collector composition may comprise the canola fatty acid, its esters and / or its salt. The Fatty Acid may comprise up to about 100 wt% of canola fatty acid, or suitable amounts such as less than about 95 wt%, less than about 90 wt%, less than about 85 wt%, less than about 80 wt%, less than 70 wt% of the canola fatty acid, preferably less than about 55 wt%, more preferably less than about 30 wt%, further preferably less than about 15 wt%, even more preferably less than about 10 wt%, even further preferred less than about 1 wt% based on the total amount of the Fatty Acid, in the collector composition.

[0043] In some embodiments, the Fatty Acid may comprise the canola fatty acid in an amount of about 1 wt% to about 5 wt%, about 5 wt% to about 10 wt%, about 10 wt% to about 15 wt%, about 15 wt% to about 19, about 19 wt% to about 23 wt%, about 23 wt% to about 27 wt%, about 1 wt% to about 30 wt%, about 30 wt% to about 35 wt%, about 35 wt% to about 40 wt%, about 40 wt% to about 45 wt%, about 45 wt% to about 50 wt%, about 50 wt% to about 55 wt%, about 55 wt% to about 58 wt%, about 58 wt% to about 61 wt%, about 61 wt% to about 65 wt%, or about 65 wt% to about 70 wt%, about 70 wt% to about 80 wt%, about 80 wt% to about 90 wt%, about 90 wt% to about 100 wt% or combinations thereof based on the total amount of the Fatty Acid in the collector composition.

[0044] The Fatty Acid of the collector composition may comprise the soya oil fatty acid, its esters and / or its salt. The Fatty Acid may comprise up to about 100 wt% of soya oil fatty acid, or suitable amounts such as less than about 95 wt%, less than about 90 wt%, less than about 85 wt%, less than about 80 wt%, less than about 70 wt% of soya oil fatty acid, preferably less than about 55 wt%, more preferably less than about 30 wt%, further preferably less than about 15 wt%, even more preferably less than about 10 wt%, even further preferred less than about 1 wt% based on the total amount of the Fatty Acid in the collector composition.

[0045] In some embodiments, the Fatty Acid may comprise the soya oil fatty acid in an amount of about 1 wt% to about 5 wt%, about 5 wt% to about 10 wt%, about 10 wt% to about 15 wt%, about 15 wt% to about 19, about 19 wt% to about 23 wt%, about 23 wt% to about 27 wt%, about 27 wt% to about 30 wt%, about 30 wt% to about 35 wt%, about 35 wt% to about 40 wt%, about 40 wt% to about 45 wt%, about 45 wt% to about 50 wt%, about 50 wt% to about 55 wt%, about 55 wt% to about 58 wt%, about 58 wt% to about 61 wt%, about 61 wt% to about 65 wt%, or about 65 wt% to about 70 wt%, about 70 wt% to about 80 wt%, about 80 wt% to about 90 wt%, about 90 wt% to about 100 wt% or combinations thereof based on the total amount of the Fatty Acid in the collector composition. Alcohol Ether Sulfate

[0046] The collector composition may include up to about 20 wt%, preferably up to about 10 wt%, still more preferably at least about 2 wt%. Alternatively, the collector composition may include the alcohol ether sulfate in an amount of about 2 wt% to about 10 wt%, about 5 wt% to about 10 wt%, about 10 wt% to about 15 wt%, about 15 wt% to about 20 wt% or any combination thereof.

[0047] Optionally, the alcohol ether sulfate may be free of alkoxylation units.

[0048] The alcohol ether sulfate may be derived from alcohols with a chain length from 12 to 14 or from 12 to 15 carbon atoms. In the first stage of production, the alcohols are converted to alkyl ethers, which are then subjected to a sulfation reaction using, for example, sulfur trioxide, chlorosulfonic acid or oleum, i.e. a mixture of sulfur oxide (VI) with sulfuric acid. Typically, there are from 2 to 3 oxide moieties in the polyoxyethylene chain, however, this number can be up to 10 EO (ethylene oxide) units depending on the application; preferably the alcohol ether sulfate is ethoxylated with 3 EO.

[0049] The general formula for alkyl ether sulfate is R-O(CH2CH2O)n-SO3M, where R represents a linear or branched alkyl group (hydrocarbon chain attached to an oxygen atom), n is the number of ethylene oxide units (also referred to as ethoxyl groups in the present disclosure), and M is a cation (like sodium or ammonium). This structure can also be represented as CH3(CH2)x(OCH2CH2)nOSO3Na, where —

[0050] x is preferably between 3 and 28;

[0051] O(CH2CH2O)n: Indicates a chain of ethoxylation, meaning it's a series of ethylene oxide units (CH2CH2O) linked together;

[0052] "n" represents the number of these units, n is between 1 and 20; and

[0053] SO3M: Represents the sulfate group, where M is the counterion, typically sodium (Na+), potassium (K+), ammonium (NH4+), calcium (Ca2+), and magnesium (Mg2+) or an amine.

[0054] Particular examples of the ether sulfate include Sodium Lauryl Ether Sulfate (SLES, also referred to as sodium laureth sulfate): CH3(CH2)ii(OCH2CH2)nOSO3Na and Ammonium Laureth Sulfate (also referred to as Ammonium Lauryl Ether Sulfate): CH3(CH2)u(OCH2CH2)nOSO3NH4.

[0055] A non-exhaustive list of ether sulfates include the following: Sodium laureth sulfate (SLES), ammonium laureth sulfate (ALS), Sodium myreth sulfate, Sodium laureth-2 sulfate (a form of SLES with a specific number of ethoxyl groups (in this case, 2)), Sodium laureth-3 sulfate, containing an average of 3 ethoxyl groups, Sodium laureth-5 sulfate, with an average of 5 ethoxyl groups, Magnesium laureth sulfate, Sodium myreth-2 sulfate (a form of myreth sulfate with a specified number of ethoxyl groups (2 in this case)), Sodium myreth-3 sulfate (myreth sulfate with a specified number of ethoxyl groups (3 in this case)), Sodium pareth sulfate, Sodium C12-15 Pareth Sulfate, Sodium Trideceth Sulfate, Sodium Coco-Sulfate, and any combination thereof.

[0056] A sodium salt of alcohol ether sulfate, which is derived from CIO-16, mainly C12, alcohols and ethoxylated with 3EO may be used in a preferred embodiment. In a preferred embodiment, the alcohol ether sulfate includes ~25% solids and has a pH ~11. The alcohol ether sulfat may function as a good foaming agent to help fatty acid dispersion and improve flotation frothing.

[0057] Fatty Acid Sulfonate The above description regarding the Fatty Acid is equally applicable to the sulfonated fatty acid, except the suitable examples of the sulfonated fatty acid do not include fatty acid esters. Therefore the above description regarding the Fatty Acid is incorporated herein by reference in its entirety as if fully rewritten in terms of a sulfonated Fatty Acid instead of the Fatty Acid, except for excluding portions referencing the fatty acid ester.

[0058] The collector composition may include up to about 10 wt%, preferably up to about 5 wt%, more preferably up to about 4 wt%, further preferably up to about 2 wt%, even more preferably at least about 0.5 wt% of the sulfonated Fatty Acid. Preferably, the sulfonated Fatty Acid comprises a fatty acid other than tall oil fatty acid, more preferably the sulfonated Fatty Acid comprises the fatty acid other than tall oil fatty acid and / or coconut fatty acid, further preferably the sulfonated Fatty Acid comprises no more than about 0.1 wt% of either or both of tall oil fatty acid and coconut fatty acid, even more preferably less than about 0.05 wt% of the of tall oil fatty acid and coconut fatty acid.

[0059] As disclosed herein the sulfonated Fatty Acid is different than the Fatty Acid.

[0060] Hydrotrope

[0061] The term "hydrotrope" herein refers to a substance which has the property of increasing the aqueous solubility of otherwise only slightly water-soluble organic chemicals. But more specifically, the hydrotrope of the present invention is a chemical substance which includes an organic group chemically bonded to a polar group. The organic group can be an aromatic, an aliphatic, or combinations thereof, which is exemplified by alkylbenzene, the carbon chain length of alkyl can range from Cl to less than C30. When the organic group is aliphatic, the carbon chain length can range from about C3 to less than C24. In further embodiments, the hydrotrope may include a straight-chain, saturated fatty acid anion, e.g., below sodium hexanoate or sodium octanoate.

[0062] The polar group of the hydrotrope can be a carboxylate, a phosphate, a phosphonate, a sulfate or a sulfonate, all of which may be in the form of a salt. The above-described polar groups may be salts of sodium (Na), ammonium, calcium, cesium, potassium or any such salt which is highly water-soluble. The sodium, ammonium, cesium and potassium are the cationic portions of these salts. Such a salt, when chemically bonded to any one of the above-described organic groups, presents the chemical substance with surprising qualities. One quality is that the chemical substance, when added to water, greatly increases the water solubility of certain organic compounds, such as Fatty Acids, preferably fatty acids, as described in the present invention.

[0063] Particularly useful hydrotropes are exemplified such as sodium hexanoate, sodium octanoate, sodium xylenesulfonate, sodium cumenesulfonate, tosylate such as sodium p-toluenesulfonate, sodium dodecylbenzene sulfonate, natural petroleum sulfonate, synthetic petroleum sulfonate, Sodium hexanoate is a sodium salt of hexanoic acid. Sodium octanoate is a sodium salt of octanoic acid.

[0064] Examples of preferred hydrotropes include an alk(en)yl aryl sulfonate, more preferably an alk(en)yl benzene sulfonate, even more preferably the alk(en)yl benzene sulfonate may comprises at least one of dodecylbenzene sulfonate, petroleum sulfonate and combinations thereof, further preferably the a I k(en )y I benzene sulfonate consists essentially of at least one of the dodecylbenzene sulfonate, petroleum sulfonate and combinations thereof. Other preferred hydrotropes may include sodium hexanoate, sodium octanoate, and combinations thereof. In particular embodiments the hydrotrope may be formed by the sulfonation of an aromatic compound. An example of suitable compounds may be any alk(en)yl aryl sulfonate. Typically, the al k(en)yl aryl may include moieties having carbon numbers ranging from about 8 carbon atoms to about 100 carbon atoms, preferably, from about 10 to about 80 carbon atoms, more preferred from about 14 to about 60 carbon atoms. Examples of suitable sulfonate compounds include but are not limited to sodium, calcium or magnesium sulfonates, natural petroleum sulfonate or alkylbenzene derived synthetic petroleum sulfonate. Preferably, the sulfonate compound comprises, or is, at least one selected from sodium sulfonates, petroleum sulfonates and its derivatives, sulfonated fatty acids and its derivatives, and combinations thereof. Preferred examples of petroleum sulfonates may include natural petroleum sulfonates and synthetic petroleum sulfonates, further preferred petroleum sulfonates include at least one of al k(en)yl sulfonates, alk(en)yl aryl sulfonates, alkyl xylene sulfonates, a-olefin sulfonates and combinations thereof. Preferably the sodium sulfonate comprises sodium alkylbenzenesulfonate, comprising a straight-chain alkylbenzenesulfonic acid.

[0065] A preferred alk(en)yl aryl sulfonate is benzenesulfonic acid having a C10-16-alkyl group, preferably a C12 group. This embodiment of the alk(en)yl aryl sulfonate has been used in collector compositions to enhance the strength of collecting power, especially for coarse phosphate particles.

[0066] In one embodiment, the sulfonate compound may comprise a petroleum sulfonate. The petroleum sulfonates may be classified as low (L) equivalent weight petroleum sulfonates typically having an equivalent weight of about 410-440 g / mole, as medium equivalent weight petroleum sulfonates (HL, referred to in this fashion because it was typically supplied as a blend of low and high equivalent weight petroleum sulfonates) having an equivalent weight of about 450-480 g / mole and high (H) equivalent weight petroleum sulfonates typically having an equivalent weight of about 490-520 g / mole. A preferred sulfonate compound is either a medium or a high equivalent weight petroleum sulfonate, more preferably the medium equivalent weight petroleum sulfonate.

[0067] These general equivalent weight ranges apply to both synthetic and natural petroleum sulfonates. The equivalent weight is measured and calculated according to ASTM D3712.

[0068] In another embodiment, a preferred range of equivalent weight of petroleum sulfonates, either natural or synthetic is from about 390 to 600, more preferable from 390 to 420, or from 420 to 450, or from 450 to 480, or from 480 to 510, or from 510 to 540, or from 540 to 570, or from 570 to 600.

[0069] Preferred amounts of the hydrotrope in the collector composition may include up to about 25 wt%, preferably up to about 20 wt%, more preferably up to about 15 wt%, further preferably up to about 10 wt%, even further preferably up to about 5 wt%, still more preferably at least about 2 wt%, still further preferably at least about 3 wt% of a hydrotrope, or alternatively an amount of the hydrotrope in the collector composition may comprise at least one of at least about 2 wt% to about 5 wt%, about 5 wt%, to about 10 wt%, about 10 wt% to about 15 wt%, about 15 wt% to about 20 wt%, about 20 wt% to about 25 wt% or combinations thereof.

[0070] Optional Components

[0071] Optionally, the Fatty Acid and / or the sulfonated Fatty Acid comprises an unsaturated compound. Preferably the, aqueous, collector composition has a pH of more than 7.0, preferably more than about 8.0, further preferably more than about 8.5, more preferably more than about 9.0. even more preferably at least about 9.5, even further preferably at least about 10, and most preferably less than about 13.0. The pH of the composition may be measured by any known method, such as but not limited to, conductivity meters, pH meters, or pH indicators.

[0072] The collector composition, preferably an aqueous collector composition, may have a viscosity of no more than about 5000 cPs, preferably no more than about 3000 cPs, further preferably no more than about 2000 cPs, more preferably no more than about 1500 cPs. The viscosities may be taken using an AMETEK Brookfield DV1 Digital Viscometer (Model: DV1MRVTJO) with a small sample adapter. The temperature was controlled using a Brookfield TC-650MX-115 circulating refrigerated bath. The spindle used was the SC4-21 inside the CS4-13R sample chamber. The highest RPM level on the viscometer was used to the point that the machine would not report errors. Maximum RPMs is 100 RPM, and the minimum is 0.5 RPM. An exemplary, but non-limiting, temperature that may be used to measure the viscosity may be about 50°F to about 70°F.

[0073] In particular embodiments of the, preferably aqueous, collector composition a weight ratio of the Fatty Acid and the sulfonated Fatty Acid to the alcohol ether sulfate, hydrotrope, preferably the alk(en)yl aryl sulfonate, and any other non-fatty acid non-water component present in the collector composition comprises at least about 1:5 to about 5:1, preferably about 1:3 to about 4:1, more preferably about 1:2 to about 2:1, further preferably about 1:1.

[0074] In additional embodiments of the, preferably aqueous, collector composition a weight ratio of the Fatty Acid to the sulfonated Fatty Acid comprises at least about 1:1 to about 20:1, preferably about 1:1 to about 5:1, about 2:1 to about 5:1, about 3:1 to less than about 20:1, more preferably less than about 15:1, further preferably no more than about 10:1.

[0075] In other embodiments of the, preferably aqueous, collector composition a weight ratio of the sulfonated Fatty Acid, the alcohol ether sulfate and the hydrotrope, preferably the alkyl benzene sulfonate, to the Fatty Acid and any other non-sulfonated and non-water compound(s) present in the collector composition comprises about 5:1 to about 1:5, preferably about 3:1 to about 1:4, more preferably no more than about 1:3, further preferably no more than about 1:2.

[0076] The various embodiments described above may be practiced in any combination thereof.

[0077] In addition to the Fatty Acid, the sulfonated Fatty Acid, the hydrotrope and the alcohol ether sulfate, the collector composition, preferably aqueous collector composition, may further comprise a caustic compound, preferably the caustic compound comprises an aqueous solution having at least 25 wt% of the caustic compound, more preferably at least about 40 wt%, further preferably at least about 45 wt% and / or preferably the caustic compound comprises at least one from the group of sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonium hydroxide and combinations thereof. The caustic compound is present in the collector composition in an amount from about 1 wt% to about 10 wt%, preferably about 2 wt%to about 8 wt%, more preferably about 2 wt% to about 7 wt%, based on the total weight of the collector composition.

[0078] Other optional elements of the collector composition, preferably aqueous collector composition, may include one or more additives selected from at least one of a pH modifier, an insoluble oil, a silicone, a fatty alcohol, a glycol and combinations thereof, preferably the additive selected from at least one of a primary alcohol, a silicone polyether and combinations thereof, preferably the additive is present in the collector composition in an amount of up to about 10 wt%, alternatively in an amount of about 1 wt% to about 2 wt%, about 2 wt% to about 3 wt%, about 3 wt% to about 4 wt%, about 4 wt% to about 5 wt%, about 5 wt% to about 6 wt%, about 6 wt% to about 7 wt%, about 7 wt% to about 8 wt%, about 8 wt% to about 9 wt%, about 9 wt% to about 10 wt% or any combination thereof.

[0079] The collector composition, preferably aqueous collector composition, may have less than about 0.1 wt%, preferably less than about 0.05 wt%, preferably devoid of a phosphorus bearing compound.

[0080] In some embodiments, the aqueous collector composition may comprises at least about 25 wt% of water, preferably at least about 35%, more preferably at least about 45 wt%, still more preferably at least about 50 wt% of water, further preferably no more than about 80 wt% of the water, even more preferably at least about 55 wt% of the water, even further preferably at least about 60 wt% of the water, still even more preferably no more than about 75 wt% of the water.

[0081] The collector composition, aqueous collector composition, may have less than about 0.1 wt%, preferably less than about 0.05 wt%, preferably devoid of fuel oil.

[0082] The collector composition, aqueous collector composition, may have less than about 0.1 wt%, preferably less than about 0.05 wt%, preferably devoid of a maleamic acid derivative.

[0083] The collector composition, aqueous collector composition, may have less than about 5 wt%, preferably less than about 4 wt%, more preferably less than about 2 wt%, further preferably less than about 1 wt%, even more preferably less than about 0.5 wt%, furthermore preferably less than about 0.1 wt% of sodium coco sulfate.

[0084] The collector composition, aqueous collector composition, may have less than about 2 wt% of a phosphorous-bearing inorganic acid or its salt, preferably less than about 1 wt%, more preferably substantially devoid of the phosphorous-bearing inorganic acid or its salt.

[0085] The collector composition, aqueous collector composition, may have less than about 2 wt% of an alkoxy-propylmaleimic acid derivative, preferably less than about 1 wt%, more preferably substantially devoid of the alkoxy-propylmaleimic acid derivative.

[0086] In some embodiments, the polyoxyethylene alkyl ether carboxylic acid or salt thereof is optionally used, and as illustrated below:

[0087] R-O-(CH2CH2O)n-CH2CO2H or its salts

[0088] Where R is a C2-20 alkyl group; and n is an integer of from 1 to 100, exemplified by AEC-25, Emulsogen CLA020, Emulsogen CLA030, and Akypo RLM 25. Exemplary salts may include Na, Ca, K, or NH4.

[0089] Alternatively, the composition may include ethoxylated tall oil fatty acid, e.g., Rolfat TFA 5-9 EO available from Lamberti Chemical Specialties.

[0090] The composition of the invention optionally comprises at least one frother, examples of frother include but not limited to aliphatic alcohols, cyclic alcohols, aromatic alcohols, alkoxy paraffins, polyglycols, polyglycol ethers, propylene oxide and polypropylene oxide, propylene glycol, polypropylene glycol and polypropylene glycol ethers, polyglycol glycerol ethers, polyoxyparaffins, natural oils such as pine oil an alcohol blend which is from the waste stream of the production of 2-ethyl hexanol and any combination thereof. There frothers are further exemplified as, n-hexanol, n-octanol, isoamyl alcohol, diacetone alcohol, borneol, ortho-cresol, 2,6-xylenol, ortho-cresol, 1, 3, 5-trialkoxypropy trioxane, DF-400, PPG-192, DF-200, AF-68, and the like, methyl isobutyl carbinol (MIBC), EP-2O2, EP 204, decyl alcohol, butoxypolyglycol basic, butoxypolyglycol, 2-ethyl hexanol, pine oil, DF-250A.

[0091] An exemplary amount of frother when present in the composition may be up to about 10 wt%, preferably at least about 1 wt%. However, suitable embodiments may be devoid of the frother.

[0092] The collector composition, preferably aqueous collector composition, is suitable for use in a direct flotation process.

[0093] The collector composition may further include a viscosity reducing agent. Suitable viscosity reducing agents are alkyl alcohols such as methanol, ethanol, propanol, isopropanol, n-butanol, tert-butanol, hexanols, or combinations thereof; glycerol, glycerol derivatives, such as glycerol ethers, phenols and their derivatives, glycol ethers and their derivatives. Glycol ethers (GEs) are classified based on their precursor molecules. Ethylene oxide-derived glycol ethers belong to the E-series, while molecules derived from propylene oxide are classified as P-series glycol ethers. E-series glycol ethers include methyl, ethyl, butyl and hexyl glycol ethers. Depending on the number of ethylene oxide repetitive units there are mono-, di- and triethylene glycol ethers. The ethylene oxide building block provides a high compatibility with water to these compounds. P-series glycol ethers (P-GEs), considered safer than E-series glycol ethers for certain applications, include methyl-, ethyl-, n-propyl-, butyl, and phenyl propylene glycol ethers. The propylene glycol ethers (P-GEs) considered here are produced through the reaction of propylene oxide and an aliphatic monoalcohol, such as methanol, ethanol, n-propanol, tertbutanol or n-butanol. The generic formula can be expressed as:

[0094] CnH2n+1(OCH(CH3) CH2)mOH or CnH2n+1(OCH2CH(CH3))mOH

[0095] where n is from 1-6 and m is from 1-4 and combinations of the pendant methyl group can vary within oligomers. The terminal hydroxyl group of a propylene glycol ether may react with another alcohol molecule to produce a dialkoxy molecule (often referred to as a glyme), and terminal hydroxyl group can also react with an acid to from an ester, the esters and dialkoxy molecules are examples of P-GEs derivatives. The exemplary P-GEs and their derivatives are propylene glycol monomethyl ether, dipropylene glycol, dipropylene glycol monobutyl ether, dipropylene glycol dimethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol tertiary butyl ether, methoxyacetic acid, 2-methoxypropionic acid, monopropylene glycol, propylene glycol monobutyl ether, propylene glycol monoethyl ether, propylene glycol ethers, propylene glycol isobutyl ether, propylene glycol isopropyl ether, propylene glycol tertiary butyl ether, propylene glycol monomethyl ether, propylene glycol monopropyl ether, tripropylene glycol, tripropylene glycol monobutyl ether, heavies poly[oxy(methyl-l,2-ethandiyl)], a-butylco-hydroxy, tripropylene glycol monomethyl ether, tri(propylene glycol) monobutyl ether, tri(propylene glycol) monomethyl ether, tri(propylene glycol) propyl ether, and combinations thereof. The E-series glycol ethers can be represented by a similar generic structure with the propyl repeating groups replaced with ethyl repeating groups. The viscosity reducing agent may be the same as or different from the frother included in the collector composition. In a preferred embodiment, the viscosity reducing agent may be present in an amount of about 0 wt% to about 10 wt%, preferably up to about 7.5 wt%, more preferably up to about 6.0 wt%, still more preferably about to about 5 wt%, based on the total weight of the collector composition.

[0096] Uses and processes

[0097] The disclosure also relates to the use of a collector composition as described above, for the beneficiation of industrial minerals, preferably phosphate. The disclosure also relates to a beneficiation process for separating phosphate contained in ore from impurities. The process may include pulping the ore to produce an ore slurry; reagentizing the ore slurry to produce a reagentized slurry by adding a composition as described above. The process may also include separating the phosphate from at least some of the impurities and collecting the phosphate in the form of a concentrate.

[0098] Optionally the reagentizing step does not include introducing a separate phosphate depressant.

[0099] Preferably, the step of reagentizing the ore slurry does not include adding a pH modifier. In some embodiments, the reagentizing step further comprises separately adding at least one of the components of the collector composition (such as the Fatty Acid and / or sulfonated Fatty Acid).

[0100] The process further may comprise combining at least two of the Fatty Acid, the sulfonated Fatty Acid, the alcohol ether sulfate, the hydrotrope and any combination thereof prior to being added to the ore slurry.

[0101] The disclosure also relates to a flotation method for separating gangue from phosphate containing ores. The method includes producing an ore slurry comprising phosphate containing ore and a collector composition as described above. The method also includes subjecting the ore slurry to flotation.

[0102] Preferably, the ore slurry does not comprise a pH modifier.

[0103] The step of subjecting the ore slurry to flotation preferably produces an underflow and an overflow, the method may further include separating one of the underflow as the gangue; and collecting the overflow as the phosphate concentrate or vice versa.

[0104] The disclosure further includes a flotation method for separating impurities from phosphate containing ore. The method may include (a) forming a slurry of a phosphate ore and water, preferably the slurry comprises an amount of water such that the slurry comprises at least about 20 wt% of solids, preferably the solids comprises particles of the phosphate ore, more preferably up to about 85 wt% solids, still preferably at least about 40 wt%, further preferably at least about 50 wt%, even more preferably at least about 70 wt% of solids; (b) adding the collector composition of any one of the preceding claims to the slurry; and (c) optionally the flotation may produce an underflow and an overflow, and the method may further comprise separating the underflow as waste and collecting the overflow as a phosphate concentrate.

[0105] The disclosure includes the following clauses 1-22:

[0106] A 1stclause is an aqueous collector composition comprising

[0107] (1) At least about 10 wt% up to about 70 wt%, preferably no more than about 60 wt%, more preferably no more than about 50 wt%, further preferably no more than about 40 wt%, even more preferably no more than about 30 wt%, still further preferably less than 30 wt%, still more preferably at least about 20 wt%, of a fatty acid, fatty acid ester, its salt or any combinations thereof, preferably the fatty acid, fatty acid ester and / or its salt comprises a non-sulfonated fatty acid, fatty acid ester and / or its salt;

[0108] (2) Up to about 10 wt%, more preferably at least about 2 wt%, of an alcohol ether sulfate; (3) Up to about 10 wt%, preferably up to about 5 wt%, more preferably up to about 4 wt%, further preferably up to about 2 wt%, even more preferably at least about 0.5 wt% of a sulfonated fatty acid or its salt, preferably the sulfonated fatty acid or its salt comprises a fatty acid other than tall oil fatty acid, more preferably the sulfonated fatty acid or it salt comprises the fatty acid other than tall oil fatty acid and / or coconut fatty acid, further preferably the sulfonated fatty acid or its salt comprises no more than about 0.1 wt% of either, preferably both, of tall oil fatty acid and coconut fatty acid, even more preferably less than about 0.05 wt% of the of tall oil fatty acid and coconut fatty acid;

[0109] (4) Up to about 25 wt%, preferably up to about 20 wt%, further preferably up to about 15 wt%, even further up to about 10 wt%, still even further up to about 5 wt%, more preferably at least about 2 wt%, even more preferably at least about 3 wt% of a hydrotrope, preferably the hydrotrope comprises an organic group chemically bonded to a polar group, preferably the polar group comprises at least one of a carboxylate, a phosphate, a phosphonate, a sulfate, a sulfonate, its salt form and combinations thereof, still preferably the hydrotrope comprises an al k(en)yl aryl sulfonate, still more preferably wherein the alk(en)yl aryl sulfonate comprises an alk(en)yl benzene sulfonate, more preferably an alk(en)yl benzene sulfonate, even more preferably the alk(en)yl benzene sulfonate comprises at least one of dodecylbenzene sulfonate, petroleum sulfonate and combinations thereof, further preferably the hydrotrope comprises at least one selected from the group of sodium hexanoate, sodium octanoate, dodecylbenzene sulfonate, petroleum sulfonate and combinations thereof; and

[0110] wherein a pH of the aqueous collector composition comprises more than 7.0, preferably more than about 8.0, further preferably more than about 8.5, more preferably more than about 9.0. even more preferably at least about 9.5, even further preferably at least about 10, and most preferably less than about 13.0.

[0111] A 2ndclause includes the aqueous collector composition of clause 1 further comprising a caustic compound, preferably the caustic compound comprises an aqueous solution having at least 25 wt% of the caustic compound, more preferably at least about 40 wt%, further preferably at least about 45 wt% and / or preferably the caustic compound comprises at least one from the group of sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonium hydroxide and combinations thereof; preferably the caustic compound may be present in the collector composition in an amount from about 1 wt% to about 10 wt%, preferably about 2 wt% to about 8 wt%, more preferably about 2 wt% to about 7 wt%, based on the total weight of the collector composition.

[0112] A 3rdclause includes the aqueous collector composition of either one of clauses 1 or 2 comprising a direct flotation collector composition. A 4thclause includes the aqueous collector composition of any one of the preceding clauses having less than 0.1 wt%, preferably less than about 0.05 wt%, preferably devoid of a phosphorus bearing compound.

[0113] A 5thclause includes the aqueous collector composition of any one of the preceding clauses comprising at least about 25 wt% of water, preferably at least about 35 wt%, more preferably at least about 50 wt% of water, still preferably no more than about 80 wt% of the water, even more preferably at least about 55 wt% of the water, further preferably at least about 60 wt% of the water, even more preferably no more than about 75 wt% of the water.

[0114] A 6thclause includes the aqueous collector composition of any one of the preceding clauses having less than 0.1 wt%, preferably less than about 0.05 wt%, preferably devoid of fuel oil.

[0115] A 7thclause includes the aqueous collector composition of any one of the preceding clauses having less than 0.1 wt%, preferably less than about 0.05 wt%, preferably devoid of a maleamic acid.

[0116] An 8thclause includes the aqueous collector composition of any one of the preceding clauses having less than about 5 wt%, preferably less than about 4 wt%, more preferably less than about 2 wt%, further preferably less than about 1 wt%, even more preferably less than about 0.5 wt%, furthermore preferably less than about 0.1 wt% of sodium coco sulfate.

[0117] A 9thclause includes the aqueous collector composition of any one of the preceding clauses wherein at least one of the fatty acid, fatty acid ester or its salt, the sulfonated fatty acid or its salt and any combination thereof comprises one of a conventional fatty acid or a saponified fatty acid.

[0118] An 10thclause includes the aqueous collector composition of any one of the preceding clauses further comprising additive selected from at least one of a pH modifier, an insoluble oil, a silicone, a fatty alcohol, an ester, other than a fatty acid ester, a glycol and combinations thereof, preferably the additive selected from at least one of a polyethylene glycol fatty acid ester, a primary alcohol, a silicone polyether and combinations thereof, preferably the additive present in an amount of up to about 10 wt%.

[0119] A 11thclause includes the aqueous collector composition of any one of the preceding clauses wherein the fatty acid, the sulfonated fatty acid and any combination thereof have an acid number of at least about 30 mg of KOH / g, preferably no more than about 280 mg of KOH / g , more preferably no more than about 230 mg of KOH / g, even more preferably no more than about 200 mg of KOH / g, furthermore preferably at least about 60 mg of KOH / g.

[0120] A 12thclause includes the aqueous collector composition of any one of the preceding clauses wherein a weight ratio of the fatty acid, fatty acid ester or its salt and the sulfonated fatty acid or its salt to the alcohol ether sulfate, the hydrotrope, preferably the alkyl benzene sulfonate, and any other non-fatty acid non-water component present in the collector composition comprises at least about 1:5 to about 5:1, preferably about 1:3 to about 4:1, more preferably about 1:2 to about 2:1, further preferably about 1:1.

[0121] A 13thclause includes the aqueous collector composition of any one of the preceding clauses wherein a weight ratio of the fatty acid, fatty acid ester or its salt to the sulfonated fatty acid or its salt comprises at least about 1:1 to about 20:1, preferably about 3:1 to less than about 20:1, more preferably less than about 15:1, further preferably no more than about 10:1.

[0122] A 14thclause includes the aqueous collector composition of any one of the preceding clauses wherein a weight ratio of the sulfonated fatty acid or its salt, the alcohol ether sulfate and the hydrotrope, preferably the alkyl benzene sulfonate, to the fatty acid, fatty acid ester or its salt and any other nonsulfonated and non-water compound present in the collector composition comprises about 5:1 to about 1:5, preferably about 3:1 to about 1:4, more preferably no more than about 1.3, further preferably no more than about 1:2.

[0123] A 15thclause includes the aqueous collector composition of any one of the preceding clauses wherein the collector composition having a viscosity of no more than about 5000 cPs, preferably no more than about 1500 cPs, determined by a method described herein.

[0124] A 16thclause includes the aqueous collector composition of any one of the preceding clauses wherein the collector composition having less than 2 wt% of an alkoxy-propylmaleimic acid derivative, preferably less than about 1 wt%, more preferably substantially devoid of the alkoxy-propylmaleimic acid derivative.

[0125] An 17thclause includes the aqueous collector composition of any one of the preceding clauses wherein at least one of the fatty acid, fatty acid ester or its salt or the sulfonated fatty acid or its salt comprises an unsaturated compound.

[0126] A 18thclause includes the aqueous collector composition of any one of the preceding clauses wherein the collector composition having less 2 wt% of a phosphorous-bearing inorganic acid or its salt, preferably less than 1 wt%, more preferably substantially devoid of the phosphorous-bearing inorganic acid or its salt.

[0127] A 19thclause is a flotation method for separating impurities from phosphate ore comprising

[0128] a. forming a slurry of a phosphate ore and water, preferably the slurry comprises an amount of water such that the slurry comprises at least about 20 wt% of solids, preferably the solids comprises particles of the phosphate ore, more preferably up to about 85 wt% solids, still preferably at least about 40 wt%, further preferably at least about 50 wt%, even more preferably at least about 70 wt% of solids;

[0129] b. adding the aqueous collector composition of any one of the preceding clauses to the slurry;

[0130] c. optionally the flotation may produce an underflow and an overflow, and the method may further comprise separating the underflow as waste and collecting the overflow as a phosphate concentrate.

[0131] A 20thclause is an aqueous collector composition comprising:

[0132] (a) at least 10 wt% up to about 70 wt%, preferably no more than about 60 wt%, more preferably no more than about 50 wt%, further preferably no more than about 40 wt%, even more preferably no more than about 30 wt%, still further preferably less than 30 wt%, still more preferably at least about 20 wt%, of a fatty acid, fatty acid ester, its salt or any combinations thereof, preferably the fatty acid, fatty acid ester and / or its salt comprises a non-sulfonated fatty acid, fatty acid ester and / or its salt; and

[0133] (b) up to about 25 wt%, preferably up to about 20 wt%, further preferably up to about 15 wt%, even further up to about 10 wt%, still even further up to about 5 wt%, more preferably at least about 2 wt%, even more preferably at least about 3 wt% of a hydrotrope, preferably the hydrotrope comprises an organic group chemically bonded to a polar group, preferably the polar group comprises at least one of a carboxylate, a phosphate, a phosphonate, a sulfate, a sulfonate, its salt form and combinations thereof, still preferably the hydrotrope comprises an alk(en)yl aryl sulfonate, more preferably an alkyl benzene sulfonate, even more preferably the alk(en)yl benzene sulfonate comprises at least one of dodecyl benzene sulfonate, petroleum sulfonate and combinations thereof, further preferably the hydrotrope comprises at least one selected from the group of sodium hexanoate, sodium octanoate, dodecylbenzene sulfonate, petroleum sulfonate and combinations thereof;

[0134] wherein a pH of the aqueous collector composition comprises more than 7.0, preferably more than about 8.0, further preferably more than about 8.5, more preferably more than about 9.0. even more preferably at least about 9.5, even further preferably at least about 10, and most preferably less than about 13.0.

[0135] A 21stclause, the aqueous collector of clause 20 having at least one of the following:

[0136] (a) up to about 10 wt%, preferably at least about 2 wt%, of an alcohol ether sulfate; and / or (b) up to about 10 wt%, preferably up to about 5 wt%, more preferably up to about 4 wt%, further preferably up to about 2 wt%, even more preferably at least about 0.5 wt% of a sulfonated fatty acid or its salt, preferably the sulfonated fatty acid or its salt comprises a fatty acid other than tall oil fatty acid, more preferably the sulfonated fatty acid or it salt comprises the fatty acid other than tall oil fatty acid and / or coconut fatty acid, further preferably the sulfonated fatty acid or its salt comprises no more than about 0.1 wt% of either, preferably both, of tall oil fatty acid and coconut fatty acid, even more preferably less than about 0.05 wt% of the of tall oil fatty acid and coconut fatty acid.

[0137] A 22ndclause, the aqueous collector composition of any one of clauses 1-18, further comprising a viscosity reducing agent, wherein the viscosity reducing agent is present in the aqueous collector composition in an amount up to about 10 wt%, preferably up to about 7.5 wt%, more preferably up to about 6.0 wt%, still more preferably about to about 5 wt%, based on a total weight of the aqueous collector composition

[0138] A 23rdclause, the aqueous collector composition of clause 22, wherein the viscosity reducing agent is selected from the group consisting of alkyl alcohols, preferably methanol, ethanol, propanol, isopropanol, n-butanol, tert-butanol, hexanols, and combinations thereof; glycerol and derivatives thereof, preferably glycerol ethers; phenols and derivatives thereof; glycol ethers and derivatives thereof; and combinations thereof.

[0139] A 24thclause, the aqueous collector composition of clause 23, wherein the glycol ether is selected from ethylene oxide-derived glycol ethers and propylene oxide-derived glycol ethers. A 25thclause, the flotation method of clause 19, wherein the aqueous collector composition further comprises a viscosity reducing agent in an amount up to about 10 wt%, preferably up to about 7.5 wt%, more preferably up to about 6.0 wt%, still more preferably about to about 5 wt%, based on a total weight of the aqueous collector composition.

[0140] A 26thclause, a flotation method of clause 25, wherein the viscosity reducing agent is selected from the group consisting of alkyl alcohols, preferably methanol, ethanol, propanol, isopropanol, n-butanol, tertbutanol, hexanols, and combinations thereof; glycerol and derivatives thereof, preferably glycerol ethers; phenols and derivatives thereof; glycol ethers and derivatives thereof; and combinations thereof.

[0141] A 27thclause, a flotation method of clause 26, wherein the glycol ether is selected from ethylene oxidederived glycol ethers and propylene oxide-derived glycol ethers.

[0142] Examples

[0143] The present invention is further illustrated by the following example. In order that those skilled in the field may better understand how the present invention can be practiced, the following examples are given by way of illustration only and not necessarily by way of limitation. Regarding the percentages of components, the percentages are by weight (wt%).

[0144] Control Example 1

[0145] A Feed was conditioned at a slurry density of 65% solids using a collector as described below without soda ash. Fuel oil was also added at the rate of 0.15 to 0.40 lbs per ton of feed in this stage as stated in Tables 1 and 2. The conditioning time and agitation speed were conventional, and known to the people who are skillful in the art.

[0146] The control collector composition included about 14 wt% of a fatty acid (non-sulfonated), about 2 wt% sulfonated fatty acid, about 8-9 wt% of an alcohol ether sulfate, about 7 wt% of caustic and the balance was water.

[0147] After conditioning, the slurry was diluted to about 30% solids and floated. The underflow of the flotation was discarded as siliceous impurities while the overflow was collected as concentrate. The flotation results of control collector composition (doesn't contain hydrotrope) are shown in Table 1.

[0148] Table 1

[0149]

[0150] Inventive Example 2

[0151] The inventive collector composition included about 16 wt% of a fatty acid (non-sulfonated), about 1-2 wt% of a sulfonated fatty acid, about 4-5 wt% of a caustic, about 3-4 wt% of a hydrotrope and about 8 wt% of an alcohol ether sulfate and the balance was water.

[0152] Using the same procedures as in Example 1, the flotation results for the collector composition containing the hydrotrope are shown in Table 2

[0153] Table 2

[0154]

[0155] The comparison of flotation results of collector with and without the hydrotrope are illustrated in figure 1.

[0156] The collector containing a hydrotrope shows surprisingly better recovery over the entire range of dosage of the study, particularly at the low dosage end. In fact, the collector including the hydrotrope (inventive collector composition) exhibited a higher recovery percentage than the control collector at more than twice the dosage of the hydrotrope containing collector (inventive collector composition at the dosage rate of 0.84 Ib / ton vs the control collector composition at the dosage rate of 1.67 Ib / ton).

[0157] Inventive Example 3

[0158] The inventive collector composition included about 22 wt% of a fatty acid (non-sulfonated), about 1-2 wt% of a sulfonated fatty acid, about 6-7 wt% of a caustic, about 4-5 wt% of a hydrotrope, about 8 wt% of an alcohol ether sulfate and about 5 wt% of viscosity reducing agent and the balance was water. The viscosity of the collector composition of Inventive Example 3 was compared to the viscosity of the collector composition of Inventive Example 3 without including the viscosity reducing agent. The results are shown in Table 3 and Fig. 2.

[0159] Table 3

[0160]

[0161]

[0162] As seen from the results in Table 3 and Fig. 2, the inclusion of a viscosity reducing agent of about 5 wt% in the inventive collector composition unexpectedly reduces the viscosity by about 80%.

Claims

What is claimed is:

1. An aqueous collector composition comprisinga. at least about 10 wt% up to about 70 wt%, preferably no more than about 60 wt%, more preferably no more than about 50 wt%, further preferably no more than about 40 wt%, even more preferably no more than about 30 wt%, still further preferably less than 30 wt%, still more preferably at least about 20 wt%, of a fatty acid, fatty acid ester or its salt, preferably the fatty acid, fatty acid ester and / or its salt comprises a non-sulfonated fatty acid, fatty acid ester or its salt;b. up to about 10 wt%, more preferably at least about 2 wt%, of an alcohol ether sulfate;c. up to about 10 wt%, preferably up to about 5 wt%, more preferably up to about 4 wt%, further preferably up to about 2 wt%, even more preferably at least about 0.5 wt% of a sulfonated fatty acid or its salt, preferably the sulfonated fatty acid or its salt comprises a fatty acid other than tall oil fatty acid, more preferably the sulfonated fatty acid or it salt comprises the fatty acid other than tall oil fatty acid and / or coconut fatty acid, further preferably the sulfonated fatty acid comprises no more than about 0.1 wt% of both the tall oil fatty acid and the coconut fatty acid, even more preferably less than about 0.05 wt% of the tall oil fatty acid and the coconut fatty acid;d. up to about 25 wt%, preferably up to about 20 wt%, further preferably up to about 15 wt%, even further up to about 10 wt%, still even further up to about 5 wt%, more preferably at least about 2 wt%, even more preferably at least about 3 wt% of a hydrotrope, preferably the hydrotrope comprises an organic group chemically bonded to a polar group, preferably the polar group comprises at least one of a carboxylate, a phosphate, a phosphonate, a sulfate, a sulfonate, or in its salt form and combinations thereof, still preferably the hydrotrope comprises an al k(en)yl aryl sulfonate, still more preferably wherein the al k(en)yl aryl sulfonate comprises an alk(en)yl benzene sulfonate, even more preferably the alk(en)yl benzene sulfonate comprises at least one of dodecylbenzene sulfonate, petroleum sulfonate and combinations thereof , further preferably the hydrotrope comprises at least one selected from the group of at least one of sodium hexanoate, sodium octanoate, dodecylbenzene sulfonate, petroleum sulfonate and combinations thereof; andwherein a pH of the aqueous collector composition comprises more than 7.0, preferably more than about 8.0, further preferably more than about 8.5, more preferably more than about 9.

0. even more preferably at least about 9.5, even further preferably at least about 10, and most preferably less than about 13.0.

2. The aqueous collector composition of claim 1 further comprising a caustic compound, preferably the caustic compound comprises an aqueous solution having at least 25 wt% of the caustic compound, more preferably at least about 40 wt%, further preferably at least about 45 wt% and / or preferably the caustic compound comprises at least one from the group of sodium hydroxide, potassium hydroxide, calcium hydroxide, ammonium hydroxide and combinations thereof and / or the caustic composition is present in the aqueous collector composition in anamount from about 1 wt% to about 10 wt%, preferably about 2 wt% to about 8 wt%, more preferably about 2 wt% to about 7 wt%, based on the total weight of the collector composition.

3. The aqueous collector composition of either one of claims 1 or 2 wherein the aqueous collector composition is a direct flotation collector composition.

4. The aqueous collector composition of any one of the preceding claims having less than 0.1 wt%, preferably less than about 0.05 wt%, preferably devoid of a phosphorus bearing compound.

5. The aqueous collector composition of any one of the preceding claims comprising at least about 25 wt% of water, preferably at least about 35 wt%, more preferably at least about 50 wt%, still more preferably no more than about 80 wt% of the water, more preferably at least about 55 wt% of the water, further preferably at least about 60 wt% of the water, even more preferably no more than about 75 wt% of the water.

6. The aqueous collector composition of any one of the preceding claims having less than 0.1 wt%, preferably less than about 0.05 wt%, more preferably devoid of fuel oil.

7. The aqueous collector composition of any one of the preceding claims c having less than 0.1 wt%, preferably less than about 0.05 wt%, more preferably devoid of a maleamic acid derivative.

8. The aqueous collector composition of any one of the preceding claims having less than about 5 wt%, preferably less than about 4 wt%, more preferably less than about 2 wt%, further preferably less than about 1 wt%, even more preferably less than about 0.5 wt%, furthermore preferably less than about 0.1 wt% of sodium coco sulfate.

9. The aqueous collector composition of any one of the preceding claims wherein at least one of the fatty acid or its salt, the sulfonated fatty acid or its salt and any combination thereof comprises one of a conventional fatty acid or a saponified fatty acid.

10. The aqueous collector composition of any one of the preceding claims further comprising an additive selected from at least one of a pH modifier, an insoluble oil, a silicone, a fatty alcohol, an ester, a glycol and combinations thereof, preferably the additive selected from at least one of a polyethylene glycol fatty acid ester, a primary alcohol, a silicone polyether andcombinations thereof, still preferably the additive present in the collector composition in an amount of up to about 10 wt%.

11. The aqueous collector composition of any one of the preceding claims wherein at least one of the fatty acid, the sulfonated fatty acid and any combination thereof have an acid number of at least about 30 mg of KOH / g, preferably no more than about 280 mg of KOH / g, more preferably no more than about 230 mg of KOH / g, even more preferably no more than about 200 mg of KOH / g, furthermore preferably at least about 60 mg of KOH / g.

12. The aqueous collector composition of any one of the preceding claims wherein a weight ratio of the fatty acid, fatty acid ester or its salt and the sulfonated fatty acid or its salt to the alcohol ether sulfate, the hydrotrope, preferably the alkyl benzene sulfonate, and any other non-fatty acid non-water component present in the collector composition comprises at least about 1:5 to about 5:1, preferably about 1:3 to about 4:1, more preferably about 1:2 to about 2:1, further preferably about 1:1.

13. The aqueous collector composition of any one of the preceding claims wherein a weight ratio of the fatty acid, fatty acid ester or its salt to the sulfonated fatty acid or its salt comprises at least about 1:1 to about 20:1, preferably about 3:1 to less than about 20:1, more preferably less than about 15:1, further preferably no more than about 10:1.

14. The aqueous collector composition of any one of the preceding claims wherein a weight ratio of the sulfonated fatty acid or its salt, the alcohol ether sulfate and the hydrotrope, the alkyl benzene sulfonate, to the fatty acid, fatty acid ester or its salt and any other non-sulfonated and non-water compound present in the collector composition comprises about 5:1 to about 1:5, preferably about 3:1 to about 1:4, more preferably no more than about 1.3, further preferably no more than about 1:2.

15. The aqueous collector composition of any one of the preceding claims wherein the collector composition having a viscosity of no more than about 5000 cPs, preferably no more than about 1500 cPs, as determined by a method described herein.

16. The aqueous collector composition of any one of the preceding claims wherein the collector composition comprise having less than 2 wt% of an alkoxy-propylmaleimic acid derivative, preferably less than 1 wt%, more preferably substantially devoid of the alkoxy-propylmaleimic acid derivative.

17. The aqueous collector composition of any one of the preceding claims wherein at least one of the fatty acid, fatty acid ester or its salt or the sulfonated fatty acid or its salt comprises an unsaturated compound.

18. The aqueous collector composition of any one of the preceding claims wherein the collector composition having less 2 wt% of a phosphorous-bearing inorganic acid or its salt, preferably less than about 1 wt%, more preferably substantially devoid of the phosphorous-bearing inorganic acid or its salt.

19. A flotation method for separating impurities from phosphate ore comprisinga. forming a slurry of a phosphate ore and water, preferably the slurry comprises an amount of water such that the slurry comprises at least about 20 wt% of solids, preferably the solids comprises particles of the phosphate ore, more preferably up to about 85 wt% solids, still preferably at least about 40 wt%, further preferably at least about 50 wt%, even more preferably at least about 70 wt% of solids;b. adding the aqueous collector composition of any one of the preceding claims to the slurry; c. optionally the flotation may produce an underflow and an overflow, and the method may further comprise separating the overflow as waste and collecting the underflow as a phosphate concentrate or the underflow as waste and collecting the overflow as a phosphate concentrate.

20. The aqueous collector composition of any one of claims 1-18, further comprising a viscosity reducing agent, wherein the viscosity reducing agent is present in the aqueous collector composition in an amount up to about 10 wt%, preferably up to about 7.5 wt%, more preferably up to about 6.0 wt%, still more preferably about to about 5 wt%, based on a total weight of the aqueous collector composition21. The aqueous collector composition of claim 20, wherein the viscosity reducing agent is selected from the group consisting of alkyl alcohols, preferably methanol, ethanol, propanol, isopropanol, n-butanol, tert-butanol, hexanols, and combinations thereof; glycerol and derivatives thereof, preferably glycerol ethers; phenols and derivatives thereof; glycol ethers and derivatives thereof; and combinations thereof.

22. The aqueous collector composition of claim 21, wherein the glycol ether is selected from ethylene oxide-derived glycol ethers and propylene oxide-derived glycol ethers.

23. The flotation method of claim 19, wherein the aqueous collector composition further comprises a viscosity reducing agent in an amount up to about 10 wt%, preferably up to about 7.5 wt%, more preferably up to about 6.0 wt%, still more preferably about to about 5 wt%, based on a total weight of the aqueous collector composition.

24. The flotation method of claim 23, wherein the viscosity reducing agent is selected from the group consisting of alkyl alcohols, preferably methanol, ethanol, propanol, isopropanol, n- butanol, tert-butanol, hexanols, and combinations thereof; glycerol and derivatives thereof, preferably glycerol ethers; phenols and derivatives thereof; glycol ethers and derivatives thereof; and combinations thereof.

25. The flotation method of claim 24, wherein the glycol ether is selected from ethylene oxidederived glycol ethers and propylene oxide-derived glycol ethers.

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