MXPA00010962A - - Google Patents

Description

COLLECTING COMPOSITIONS OF HYDROXAMIC ACID OIL MIXED WITH OIL AND OIL PRODUCTION PROCESS OF THE SAME FIELD OF THE INVENTION Alkyl or alkaryl hydroxyacids and their salts are well-known collectors for the flotation by foam of oxide minerals. Soviet workers have found a variety of applications for such alkyl hydroxamic acids, such as those described by Pradip and Fuerstenau, Mineral Flotation with Hydroxamate Collectors, Reagents in the Minerals Industry, Ed. M.J. Jones and R. Oblatt, Inst. Min. Met., London, 1984, pp. 161-168, a recent review that summarizes the flotation application of alkyl hydroxamic acids. 'Hydroxamic acids have been used for the flotation of metals or minerals such as pyrochlor, fluorite, huebnerite, wolframite, cassiterite, muscovite, phosphorite, hematite, pyrolusite, rhodonite, crisocola, alachite, barite, calcite, and rare earths. The R? F. : 124239 themselves are generally stronger and more selective than fatty acids, fatty amines, petroleum sulfonates and conventional alkyl sulfates. However, commercially used methods of producing alkyl or alkaryl hydroxamic acid or their salts are tedious and unsafe from the point of view of industrial production. A process for the production of potassium alkyl hydroxamate is described in Organic Synthesis, Vol. II, page 67. In the process described, the KOH and NH2OH solutions. HCl in methanol are combined. After the by-product KCl is separated by filtration, the filtrate is combined with a liquid mixture of methyl caprylate and methyl caprate, and then allowed to stand for 24 hours, the crystals produced are separated by filtration. The major disadvantage of this method includes low yields, the use of a large amount of toxic and flammable methanol, and the use of potassium hydroxide, which is more expensive than sodium hydroxide. Furthermore, the industrial scale filtration of a methanolic reaction mixture is clearly undesirable from a safe point of view. U.S. Patent No. 3,922,872 to Hartlage claims an improved method of production of fatty hydroxamates. The hydroxylamine sulfate and the methyl ester of a fatty acid are reacted in the presence of dimethylamine in a slurry of anhydrous lower alcohol. The free hydroxamic acids formed are neutralized with dimethylamine or an alkali metal base to yield an ammonium or alkali metal salt, which is precipitated, and filtered and dried. However, the described process also employs flammable lower alcohols, such as methanol, ethanol or isopropanol, requiring filtration of the final hydroxamic product, which is risky. In addition, because of the heterogeneous nature of the reaction, the reaction rate is very slow, for example, in the order of 15 hours in methanol and 5 days in isopropyl alcohol, and the yields are relatively low, that is, in the order of approximately 75 percent.

Several Russian workers have reported methods for the production of alkyl hydroxamic acids and their salts in aqueous alkaline medium. Gorlovski, et al., Vses. Soveshch, po Sintetich. Zhirozameni telyam,.

Pover khnos tnoakt i vn, Veschestvam i Moyushchim Sredstvam, 3rd. Sb. , Shebekino, 1965, 297-9 Chem. Abst. 66, 4983h, 1967, reports the production of sodium alkyl hydroxamates by reacting the methyl ester of a carboxylic acid of C7.9 with an aqueous solution of hydroxylamine sulfate and NaOH in a molar ratio of 1: 1.22: 2.2 and a temperature 55 ° C or lower. Shchukina et. al., Khim. Prom., Moscow, 1970, 49 (3) 220, reports a yield of only 72 to 78 percent of the hydroxamic acid of C7, free g by reacting the methyl ester, hydroxylamine sulfate, and sodium hydroxide for two hours at 20 ° -25 ° C and one hour at 55 ° -60 ° C, followed by acidification at pH 4-5 at temperatures below 40 ° C. Shchukina et al., in Sin. Primen Novykh Proverkh. Veshchestv, 1973, 123-31 reported in C.A. 80, 1974, 95199K, also reports a simple laboratory method for the production of a reagent designated as IM-50 of C7-g esters. Russian workers, in Russian Patent No. 390,074, Chem. Abst. 79, 115162C (1973), and in Zh. Prikl, Khim, (Leningrad) 1972 45 (8), 1895-7, Chem. Abstract 78, 29193m 1973, reports improved yields with the use of 3 to 5 percent of an anionic emulsifier in an aqueous alkaline medium. The use of an anionic surfactant such as sodium lauryl sulfate (3-5 percent based on the weight of the methyl ester), reportedly gives an improved yield of 61.2 percent for acidic and ihydroxamic acid and 89 percent for capric acid. ihi droxámi co. To obtain the required yields, however, 40 mole percent excess hydroxylamine hydrochloride or sulfate is required. In addition, both the sodium salts or the free hydroxamic acids recovered are solids, which are difficult to handle and process. Russian Patent No. 513,970, May 15, 1976, Chem. Abst. 85, 66277g, 1976, describes the formation of a solution of hydroxamic acids of C3 to free Cu mixed with hydrocarbons for use as a flotation agent. The described hydroxamic acids are formed by treating carboxylate esters with the hydroxylamine sulfate salt in an alkali medium, and then treating the resulting sodium alkyl hydroxamates with a mineral acid in the presence of 100-250 weight percent of a hydrocarbon that contains less than 20 percent organic polar components, for example, alcohols or very high esters. The aqueous layer containing NaCl or Na 2 SO 4 is discarded as fluent. Because of the incomplete reaction of the starting ester, this process is inefficient producing a product that contains significant amounts of the starting ester that did not react. U.S. Patent No. 4,629,556 describes the removal of various colored impurities from kaolin clays using alkyl, aryl or alkyl aryl hydroxamates as collectors. The described hydroxamates are produced by reacting the free hydroxylamine with the methyl ester of an organic acid having an appropriate long chain and hydrocarbon configuration in a non-aqueous medium, such as methanol, in a manner similar to the methods described above. The U.S. 4,871,466 describes a method for the production of alkyl or alkaryl hydroxamic acids and / or salts. In the method described, the methyl or ethyl ester of a fatty acid having from 6 to 22 carbon atoms is reacted with a salt of hydroxylamine and an alkali metal hydroxide in the presence of a mixture of water, an alcohol of Ce to C22, and, preferably, a cationic or non-ionic surfactant. The reaction described results in the formation of a hydroxamate solution, which can be used without further processing in the flotation by foam of minerals without sulfur, or it is made acidic to form a liquid alcoholic solution of the acid previously used in the process of floatation. The process described eliminates the need for extensive and dangerous recovery steps, such as filtration, is relatively fast, taking only three to five hours for completion, and provides highly favorable conversions to hydroxamates. However, the final product of the described method contains some unreacted starting ester. Advances in the production and realization of alkyl hydroxamate collectors are still required, for example, the handling of solid products is difficult in a large scale of production, and the complexity and cost of production is increased. can overcome by carrying out the reaction in the presence of alcohols, as taught in US Patent No. 4,871,466, as described above, the use of alcohols from Cs to C2 leads to lower yields through the competent transesterification and hydrolysis reaction of the methyl esters, for example, carboxylic acids and other carbonyl components derived from the starting ester.Also, where the hydroxamic acid collectors are used in the flotation process, the shorter chain alcohols, for example Cs, can produce an uncontrollable frothing or producing undesirable foam properties, increasing the recovery of unwanted minerals S, and longer chain alcohols, that is, Cío and higher, can reduce the froth substantially, which is a serious concern in the flotation column where a certain amount of controlled foam phase is necessary. Furthermore, in certain applications, depending on the mineral value that is floating, the higher alcohols can be adsorbed on the mineral value in a reverse configuration, ie they can be adsorbed with the polar group exposed to the water phase, therefore reducing the hydrophobicity on the mineral value that is diffused by the alkyl hydroxamic acid, resulting in the reduced recovery of the mineral value. Commercial alcohols, which can be expensive, also have a very strong offensive odor sometimes, which varies with the length of the chain. Therefore, this remains a necessity for alkyl hydroxamic acid collectors and a process for the preparation of collectors that overcome the problems described above. The present invention provides such collectors and a process for the preparation thereof.

BRIEF DESCRIPTION OF THE INVENTION The invention relates to collector compositions for use in the removal of impurities from metallic minerals, and to methods, for the production and use of such collector compositions. Typically, a collecting composition of the invention comprises a mixture of a C6 to C22 fatty hydroxamic acid and an oil, wherein the oil is preferably selected from the group consisting of hydrocarbon, vegetable, plant, and animal oils. , and a fatty triglyceride oil is more preferable. Preferred hydrocarbon oils include, but are not limited to, aliphatic hydrocarbons, aromatic hydrocarbons, and mixtures thereof, such as benzene, xylene, toluene, mineral oil fractions, kerosene, naphthas, and petroleum fractions. Preferably, the hydroxamic acid is present in the compositions of the invention in an amount of from about 5 to about 70 weight percent, more preferably from about 10 to about 50 weight percent, and the oil is present in an amount from about 10 to about 95 weight percent, more preferably from about 20 to about 70 weight percent, based on the weight of the composition. Optionally, the collector composition further comprises up to about 70 percent, preferably, from about 10 to about 50 percent by weight, of a foam former. The collector compositions of the invention can be prepared by reacting an ester of a C6 to C22 fatty acid with a hydroxylamine salt, preferably a sulfate or hydroxylamine hydrochloride salt, and a base in the presence of an oil and water to produce an alkyl hydroxamate salt. The alkyl hydroxamate salt is then acidified, forming an organic layer and an aqueous layer, wherein the organic layer contains a fatty hydroxamic acid of Ce to C22 substantially free of transesterification products and ester hydrolysis, and the organic layer is separated from the aqueous layer to provide a mineral collection composition, comprising a mixture of C0 C22 fatty acid hydroxamic acid and oil. The beneficial realization of the collector compositions of the invention is significantly improved when compared to the compositions of the prior art, due to a lack of alcohol and a substantially reduced amount of the starting or fatty ester in the collector compositions. Generally, the collector compositions of the invention are substantially free of starting ester, so that the amount by weight of the C6 to C22 fatty acid ester or starting ester is less than the amount by weight of the hydroxamic acid. Typically, the amount of the fatty acid ester or starting ester present in the collector compositions of the invention is 50 percent less than the amount of hydroxamic acid, preferably less than 20 percent, and, more preferably, less than 10 percent. one hundred percent of the amount of hydroxamic acid. Useful esters in the process of forming the collector compositions of the invention include, but are not limited to, methyl and ethyl esters of caproic acids, enanthanic acid, caprylic acid, pelargonic acid, caproic acid, undecanoic acid, lauric acid, tr idecanoic acid, myricstic acid, adconic pent acid, palmitic acid, margaric acid, stearic acid, oleic acid, benzoic acid, ethyl benzoic acid, salicylic acid, a-naphthoic acid, ß-naphthoic acid, cyclohexyl carboxylic acid, and cyclopentyl carboxylic acid. The collector compositions of the invention can be used to remove impurities from sulfide-free metal ores by forming an aqueous slurry of the metallic ore, conditioning the slurry of metallic ore with the collector composition of the invention, which is generally prepared by the method described above, and separating the impurities and the collecting composition from the metallic mineral.

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to useful alkyl hydroxamic acids and to the production of such alkyl hydroxamic acids useful by the reaction of the methyl or ethyl ester of a fatty acid having 6 to 22 carbon atoms with a hydroxylamine salt and an alkali metal hydroxide in the presence of water, either a hydrocarbon oil or a fatty oil derived from plants, animals, or fish, or mixtures thereof, and preferably, with an optional cationic or non-ionic surfactant. The resultant alkyl hydroxamate salt is subsequently acidified with an acid, and the oil / fatty acid solution of the hydroxamic acid is separated from the aqueous phase, resulting in the formation of a liquid solution or a hydroxamic acid paste. The hydroxamic solution or paste can then be used without further modification in flotation by mineral foam without sulfur, such as kaolin clay, or can be further diluted with foam formers, such as, for example, pine oil, C5 to C8 aliphatics, polyglycols, polyglycol ethers, etc., to provide an adequate liquid solution in the miner l flotation process. The hydroxamic acid collector compositions of the invention are produced in high yields, typically higher than 90 weight percent, and typically contain substantially less unconverted starting ester and the undesirable side reaction products that result of the transesterification and hydrolysis of the starting ester, such as, for example, carboxylic acids and other carbonyl products, of the compositions of the prior art. As a result, the embodiment of the collector compositions of the invention is significantly improved when compared to prior art compositions. The process of the invention for the production of alkyl hydroxamic acids eliminates the need for dangerous and extensive recovery steps such as filtration, is relatively rapid, being completed only in 3 to 5 hours, and results in extremely high conversions, ie, in the order of 90 to 100 percent, due to the elimination of the competent transesterification reactions, and, therefore, provides high performances of the processes of the prior art. When the optional surfactant is used in the process of the invention, the amount of. The required surfactant is smaller than that required in the processes of the prior art. In contrast to the prior art references described above, the use of an oil as a carrier from the start of the preparation of the hydroxamic acid, produces a better dispersion of the chemicals, better handling of the reactor on a long manufacturing scale, more uniform heat distribution, high hydroxamic acid yields, and better reaction control and acidification. In addition, when used in the flotation by sulfur-free mineral foam, the oily solutions of the hydroxamic acids are significantly more effective than prior art compositions, yielding high mineral value yields and recovery degrees. In general, used oils tend to be neutral foam, different alcohols, which have a very small effect on the foam. The neutrality of the relative foam of the oily solutions of the hydroxamic acids allows the use of separate alcohol foam formers to independently control the properties of the foam phase as desired. With the process of the invention, the hydroxamic fatty acids are produced by reacting a methyl or ethyl ester of a fatty acid having 6 to 22 carbon atoms, and, preferably, at least 8 carbon atoms, with a hydroxylamine salt and an alkali metal hydroxide in the presence of water, and an oil, selected from the group of hydrocarbon oils, fatty oils, or mixtures thereof. The reaction proceeds according to the equations: RCOR1 + NH2OH • HX + 2MOH + MX + R OH + 2H2O z RCNHOM + HX + MX wherein R is an alkyl group from e to C22, a C6 to Cio aryl, or a C7 to C 1 alkaryl; M is an alkali metal; R1 is methyl or ethyl, and X is a halide, sulfate, bisulfate, phosphate, nitrate or similar anion residue of a mineral acid.

Useful acidic esters include the methyl and ethyl esters of such carboxylic acids such as caproic acids (C6), enanthic acid (C7), caprylic acid (Cs), pelargonic acid (C9), caproic acid (Cio), undecanoic acid (Cu) ), lauric acid (C? 2), tridecanoic acid (C? 2), tridecanoic acid (C? 3), myristic acid (Ci4), pentadenoic acid (C15), palmitic acid (Cie), margaric acid (C?) , stearic acid (C? 8) and the like, in addition to oleic acid (Cis), benzoic acid, ethyl benzoic acid, salicylic acid, α- and β-naphthoic acid, cyclohexyl carboxylic acid, cyclopentyl carboxylic acid etc. The ethyl esters of the above carboxylic acids can also be used, but they require a higher reaction temperature than the methyl esters. Hydroxylamine salts, such as sulfate or hydrochloride, can also be used. Suitable alkali metal hydroxides include sodium hydroxide, NaOH, potassium hydroxide, KOH, and the like. Amines such as ammonia, diethylamine, etc. they can be used in place of hydroxides. Suitable acids are hydrochloric, hydrobromic, sulfuric, nitric, etc. As described above, the use of a cationic or non-ionic surfactant is preferred. Examples of useful surfactants include nonionic surfactants, such as alkyl poly e t i lenoxy compounds represented by the formula: RO (EO) n-H, wherein R is Cs to Cis alkyl, EO is ethyleneoxy and n is an integer from 1 to 10, as well as the reaction products of ethylene oxide and higher alkylene oxides with active hydrogen compounds, such as phenols, alcohols , carboxylic acids and amines, for example, alkyl, enoxylene, 1-enoxy ethanols. Suitable cationic surfactants include quaternary ammonium or alkyl ammonium salts, for example, tetraalkyl ammonium chloride or bromide, dodecyl ammonium hydrochloride, dodecyl trimethyl ammonium quaternary chloride and the like, and ethoxylated fatty amines. Other suitable surfactants are described in the McCutcheon book of detergents and emulsifiers, the contents of which are incorporated herein by reference. Also included in the aforementioned surfactants are the polymerizable and oligomeric surfactants described on pages 319-322 of Blackley, Emulsion Polymerization Theory and Practice, John Wiley and Sons (1975), the contents of which are hereby incorporated by reference. Examples of such oligomers include alkali and ammonium metal salts of functionalized oligomers, said by Uniroyal Chemical under the brand name "Polywet", and copolymers of acetonitrile and acrylic acid having molecular weights of less than 2,000, which are prepared in the presence of chain terminating agents such as n-octyl mercaptan. Examples of polymerizable surfactants include sodium salts of 9- and 10- (acrylamido) acid tearico and the like. The effective amounts of the surfactant vary from about 0.5 to 3 weight percent, of the alkyl ester, preferably about 1 to 2 weight percent, with the same bases. The reaction temperature may vary from about 15 55 ° C preferably from about 25 ° to 35 °. The amount of water used should be sufficient to dissolve the hydroxylamine salt, and may vary from about 15-50 percent, generally depending on the concentration of the hydroxylamine salt solution. The amount of oil used in the reaction may also vary from about 15 to 50 percent, and is preferably sufficient to maintain the liquid reaction mixture throughout the course of the reaction at the selected temperature. The oil can be any suitable oil that will provide the result of the invention, such as hydrocarbon oils, including, but not limited to, aliphatic hydrocarbons, aromatic hydrocarbons, and mixtures of the aliphatic and aromatic hydrocarbons. Preferred hydrocarbon oils include, but are not limited to, benzene, xylene, toluene, mineral oil fractions, kerosene, naphthas, petroleum fractions, and the like. The most preferred hydrocarbon oils are low odor hydrocarbon oils, preferably a paraffin oil, containing less than about 1 percent aromatics. The oil may also be a fatty oil, such as a triglyceride oil, which is a glycerol ester with fatty acids, substantially free of polar components, such as hydroxyl groups. These triglyceride oils are more frequent, derived from animals, plants or fish rendering, squeezing or extracting the solvent. The fatty oils that may be used include, but are not limited to, soybean oil, corn oil, canola oil, sunflower oil, peanut oil, cod liver oil, shark liver oil, and oils of plants, animals or similar fish. The oil used in the present invention can also be a mixture of a hydrocarbon oil and a fatty oil. When the reaction between the methyl ester and the hydroxylamine is complete, and the alkyl hydroxamate salt has formed, the hydroxamate salt is acidified by the addition of acid, forming two phases, which will be kept at a sufficiently high temperature to avoid solidification of the phase of the organic product. The aqueous phase is then removed by decantation or by the method described in US Patent No. 3,933,872, incorporated herein by reference. The organic phase contains the alkyl hydroxamic acid collector, and is used as a flotation collector, either when it is formed or after the addition of a foam former and / or other additives. Useful foam formers include pine oil, aliphatic C5 to C8 alcohols, polyglycols, polyglycol ethers, etc. Other types of additives can also be incorporated into the diluent system specifically to improve performance. Examples of useful additives include petroleum sulfonates, sulfosuccinates, ethoxylated or propoxylated alcohoctants, etc., which increase the performance of alkyl hydroxamic acids. The present invention also relates to new compositions produced by the process described above. The compositions of the invention comprise a fatty hydroxamic acid, a hydrocarbon oil or a fatty oil, and, optionally, a "foam former or other additive incorporated in the diluent system to improve performance When a surfactant is used in the production of The hydroxamic fatty acids of the invention, the residual teratocyte may also be present in the composition The content of alkyl hydroxamic acid varies from about 5 percent to about 70 percent, preferably from about 10 percent to about 50 percent, and the content of the oil varies from about 10 percent to about 95 percent, preferably from about 20 percent to about 70 percent.If a foam former is added, it can be used in an amount of up to about 70 percent of the total composition, preferably in the approximate range you get 10 to about 50 percent. If other additives are incorporated to increase performance, they may be used in amounts ranging up to about 20 percent of the diluent, preferably about 5 to about 10 percent. The compositions described above are useful in the flotation by sulfide-free metal mineral foam, such as those mentioned above, including copper ore, iron ore, rare and rare earth metallic minerals, and more particularly, in the benefit of clays. Useful flotation methods are well established, and are known to those of ordinary skill in the art. The methods generally involve grinding ore to release mineral values and providing ore particles that are sized for flotation. The pH of the pulp of the mineral of the earth is adjusted, and it is conditioned with prescribed reagents. and preselected, such as collectors, foam formers, modifiers, and dispersants. With some minerals, such as glass sands, clays, residues, etc., the material fed as mine is already finely divided and, therefore, no additional crushing is required. In the case of the benefit of the clays, for example, substantially no crushing of the feed as a mine is required, because the average particle size is of the order of a few microns. The largest impurities in kaolin clay are anatase, Ti0, and complex ion mineral, which imparts color to clay, and diminishes its luster, thus producing clay not suitable for many of its applications where purity and luster are absolutely essential. Conventionally, the removal of such impurities is carried out by a variety of methods, one important being the flotation using fatty acid from the liquid resin. In foam flotation for the benefit of the clay, where the clay is made in a slurry in an aqueous medium, conditioned with an effective amount of a dispersing agent and collector, and floated, the method of the invention comprises the use as the collector of the above new compositions, that is, the hydroxamic acid solution, in amounts ranging from about 0.1 to about 18 pounds per ton of metallic ore, preferably 0.5 to 6 pounds per ton. The new process of the present invention results in the recovery of clays with high yields, which has low Ti02 content and increases its brightness. As a first step in carrying out such a process, the clay to be purified is completely mixed in water, that is, it is mixed with water to form a suspension, at an appropriate solids concentration, as described in US Pat. 4,629,556, the contents of which are incorporated herein for reference.

A relatively high pulp density, in the range of about 35 to about 70 weight percent solids, is preferred although the action of extracting internal particles in the pulp helps release them. colored impurities from the surface of the clay particles. Following conventional practice, a suitable dispersant, such as sodium silicate, polyacrylate, or polyphosphate, is added during the mixing of the pulp in an amount of, for example, about 1 to about. 20 Ib per ton of dry solids, enough to produce a very well dispersed fused clay. An alkali, such as ammonium hydroxide, is also added, which is necessary to produce a pH above about 6, and preferably ranges from about 8 to about 10.5. according to the invention, the hydroxamate collector is then added to the dispersed clay under conditions, i.e., proper stirring speed, optimum density of the pulp, and suitable temperature, which allows the reaction between the collector and the colored impurities of the clay in a relatively short time, generally not greater than about 5 to about 15 minutes. When the clay has been conditioned after the addition of the collector, it is transferred to a flotation cell, and typically diluted to a pulp density that is preferably in the range of about 15 to about 45 weight percent solids. The operation of the foam flotation machine is operated in a conventional manner. After an appropriate period of operation, during which the titanium impurities are removed with the foam, the suspension of the clay remaining in the flotation cell can be leached for the removal of the residual iron oxides, filter, and dry from any conventional manner known in the art.

EXAMPLES The following non-limiting examples are only illustrative of the preferred embodiments of the present invention, and are not to be construed as limiting the invention, the scope of which is defined by the appended claims. All parts and percentages are by weight unless otherwise specified.

Comparative Example A Following Wang's procedure, as described in U.S. 4,871,466, for comparative purposes, part of the hydroxylamine sulfate was dissolved in 264.4 parts of water in a suitable three-neck reaction vessel equipped with a condenser, a mechanically operated stirrer and a thermometer. Then, hydroxylamine sulfate was dissolved, 273.8 parts of dodecyl alcohol, 4.8 parts of a 50 percent dioctyl chloride / decyl dimethyl ammonium surfactant, and 200 parts of methyl caprolone / capr ate, the starting ester. The reaction mixture was cooled to 10-15 ° C with stirring in an ice / water bath, and 200 parts of 50 percent of a sodium hydroxide solution (NaOH) were slowly added through an addition funnel. During the addition of sodium hydroxide, the temperature was maintained at 15 to 20 ° C. After the caustic addition, the temperature was allowed to rise to 25 ° C, and the reaction was continued for 4 to 5 hours at 25 to 30 ° C. At the completion of the reaction, that is, when the IR spectrum of the reaction mixture shows no trace of the ester band at 1175 cm "1, 225.4 parts of 30 percent sulfuric acid were added to the reaction mixture, and two phases were formed and separated.A titration analysis of the upper organic layer (513.7 parts), a solution of hydroxamic acid in dodecyl alcohol, indicated 32 percent hydroxamic acid in contrast to the theoretical yield of 39.2 percent, representing a yield of 81.7% based on the amount of the starting ester.An NMR analysis indicated the presence of other components in the organic layer, including 7.1 percent by weight of the capr and the unreacted methyl toprofet, 8.6%. weight percent of C8 to C14 carboxylic acids derived from the starting methyl esters, and 7.1 weight percent of other carbonyl components derived from the starting ester wherein the s percentages are based only on the total weight of hydrous oxaamic acid, unreacted ester, and other reaction products in the alcohol solvent. The amount of hydroxamic acid is .77.2 percent.

Comparative Example B Following the procedure described in Russian Patent 513,970 for comparative purposes, 992 parts of 12 percent of an aqueous solution of hydroxylamine sulfate were introduced into a suitable three-neck reaction vessel equipped with a condenser, a mechanically operated stirrer, and a thermometer. Following the addition of hydroxylamine sulfate solution, 168.5 parts of caprylate / caprat or methyl were added, followed by the slow addition with stirring of 162.4 parts of 50 percent of an ammonium hydroxide solution through a funnel of addition during a period of 30 minutes. During the addition of sodium hydroxide, the temperature was maintained from 26 ° to 28 ° C. After the caustic addition, the reaction was continued for 2 hours, while it was constant to maintain the temperature at 26 ° to 28 ° C. After two hours of holding the period, 79.46 parts of concentrated sulfuric acid (96.4%) were slowly added, and the temperature was allowed to increase to 40 ° C to keep the resulting hydroxamic acid in liquid form. At this time, 169.5 parts of kerosene were added, and the acid / rosin layer was separated from the lower aqueous layer. The product layer (344.85 parts) was analyzed by titration, and found to contain 17.4 weight percent hydroxamate in contrast to the theoretical yield of 50 weight percent, representing a yield of 35% alkyl hydroxamic acid. The percentage of hydroxamic acid is 35%, of other carbonyl components is 14% and of the starting ester is 51%, as determined by NMR. The weight ratio of the starting ester to alkyl hydroxamic acid, as measured using NMR, is 1.46 to 1.

Comparative Example C The process of Comparative Example B was repeated using 496 parts of a solution of 12 percent hydroxylamine sulfate, 84.25 parts of caprylate / methyl caprate, 81.2 parts of a 50 percent NaOH solution. and 39.73 parts of sulfuric acid. Again the temperature after the addition of sulfuric acid was allowed to rise to 40 ° C, and 211.9 parts of kerosene were added. The upper organic layer was separated from the aqueous layer and analyzed by titration, indicating a 10.54 weight percent hydroxamate yield in contrast to the theoretical yield of 28.57 weight percent, representing a 37 percent yield. NMR analysis showed 37% hydroxamic acid, 13% other carbonyl components and 50% starting ester. The weight ratio of the starting ester to alkyl hydroxamic acid, as measured using NMR analysis, is 1.36 to 1.

EXAMPLE 1 In a suitable three-necked reaction vessel, equipped with a condenser, a mechanically operated stirrer, and a thermometer, 1627 parts of hydroxylamine sulfate were dissolved in 4066 parts of water, and 4145 parts of soybean oil, 67 parts, were introduced. of a 50 percent dioctyl 1 / decyl dimethyl ammonium chloride surfactant, and 3036 parts caprylate / methyl caprate. The reaction mixture was cooled to about 10 to about 15 ° C with stirring in an ice / water bath, and then 3028 parts of 50 percent sodium hydroxide were added slowly through an additional funnel keeping the temperature at about 15 at about 20 ° C throughout the addition. After the addition of sodium hydroxide, the temperature was allowed to rise to 25 ° C, and the reaction was continued for about 4 to about 5 hours at a temperature of about 25 to about 30 ° C. the completion of the reaction was determined from the IR spectrum of the reaction mixture, which showed no trace of the ester band at 1175 cm.l Two phases were formed by the addition of 5120 parts of sulfuric acid at 18.76 cm. percent, and separated, while maintaining the temperature prior to the solidification temperature of the hydroxamic acid, for example, about 30 ° to 40 ° C. The top organic layer, 7719 parts, was found to contain 38.5 weight percent of free hydroxamic acid, corresponding to a yield of 97.5 percent, when compared to the theoretical yield of 39.5 percent. Only traces of the starting methyl ester and acids derived by hydrolysis are present, as evidence of the high yield of the product. The organic solution, which was obtained by the separation phase, is compatible with the fatty acids of the liquid resin, which contains caprylic / capra hydroxamic acid in soybean oil, and is liquid at temperatures above about 30 ° C, and a paste at low temperatures.

EXAMPLE 2 The procedure described in Example 1 was repeated. However, following the acidification and separation of the phases, 1281 parts of MIBC alcohol foam former were added. The resulting liquid product has a hydroxamic acid content of 32.7 percent, and remained liquid at a temperature of 20 ° C. the liquid product again was found to be compatible with the fatty acid of the liquid resin.

EXAMPLE 3 The procedure of Example 1 was repeated, replacing the soybean oil with hydrocarbon oil, Escaid 110. Following the separation phase, the hydroxamate content of the resulting oily solution is 39 percent, representing a yield of 98.7 percent of hydroxamic acid. The NMR analysis showed the presence of at least 3 percent of the starting ester and carboxylic acid. The product is substantially free of starting ester, having a weight ratio of the starting ester not converted to alkyl hydroxamate of only 0.02 to 1. The solidification point of the product is 32 ° C.

EXAMPLE 4 The procedure of Example 1 was repeated, replacing the soybean oil with a corn oil. Following the separation phase, the hydroxamate content of the resulting oil solution. it is 38.9 percent, representing a yield of 98.5 percent hydroxamic acid, and the solidification point is approximately 30 ° C.

EXAMPLES 5-8 The procedure of Example 1 was again followed, except that the caprylate / methyl caprate was replaced by an equivalent amount of methyl stearate, Example 5, ethyl oleate, Example 6, methyl palmitate, Example 7, or methyl naphtolate , Example 8. Similar conversions of methyl esters to hydroxamic acids were achieved, and the solidification points were similar to those obtained in Example 1.

EXAMPLES 9-15 Four thousand parts dry base of fresh kaolin was thoroughly mixed in approximately 60 percent solids for six minutes in a Morehouse Cowles Dissolver, Model: W12 laboratory, with water and 6 parts of sodium silicate. A prescribed amount of the collector, together with the foam former AEROFROTH (R) 70, was then added to the slurry of well-dispersed clay, and the mixture was conditioned in the same mixer for an additional six minutes. After conditioning, the whole pulp was diluted with water at 20 percent solids. A sufficient amount of the diluted pulp was taken to provide 2000 parts of the fresh kaolin clay in a flotation cell of the 4.5-liter Denver laboratory. Flotation was performed at 20 percent solids by carefully regulating the air flow for up to 15 minutes while stirring at 1200 rpm. The flotation of this sample of kaolin clay, designated Sample A, was significantly improved with the new collectors of the present invention, Examples 9 to 14, when compared with the co-collector system of the standard plant, which is a combination. / 1 of the liquid resin with a collector made in accordance with US Patent No. 4,871,466, a product of the commercial alkyl hydroxamate collector used in Example 15. The results of the comparison are given in Table I.

Table I: Results of the Denver Flotation Test Work in Kaolin Sample A EXAMPLE 16 The alkyl hydroxamate composition of Example 1 was evaluated at a dosage of 1.25 Lbs./T with 0.25 Lbs./T of the AF-70 foam former using a laboratory column cell incorporating a bubbling microcell generation system. The yield of the clay was 97.8 percent and the Ti02 content of the flotation product was 0.421 percent.

EXAMPLES 17-29 The flotation tests were performed on three additional kaolin clay samples designated here as samples B, C and D. These crude clay samples have characteristics summarized in Table II below: Table II: Characteristics of the Samples of Clay B D A Premier Mili Agitator mixer was used to thoroughly mix 796 parts of fresh wet kaolin clay, equivalent to approximately 651 parts of dry solids, with water and 1.3 parts of sodium silicate at 60 percent solids for 6 minutes. Then a prescribed amount of the collector, either a collector of the present invention or a collector of the prior art for comparative purposes, was added to the well dispersed watered clay paste and the mixture was conditioned in the mixer for an additional 6 minutes. . The conditioned pulp was then transferred to a 2.3 liter flotation cell, diluted with water to approximately 25 percent solids, stirred at 1000 rpm, and floated with a carefully regulated air flow in the range of approximately 0.1. at 1.5 l / min of air for up to approximately 30 minutes. The floating product containing colored impurities, more titaniferous minerals and anatase impurities, and the product of the non-floated cell, containing the bright and clean clay values, was filtered, dried, and tested for Ti02 and Fe203. The results are described in Table III below: ro ro? - > I heard o o n TAB ni hI The results for sample B of the raw clay demonstrate the superiority of the new collectors of the present invention over both the fatty acid of the liquid resin and the commercial collector of Example 15. The best performer in this crude, based on both the Product yield as the reduction of Ti02, is the composition of Example 2, which produces a clay product with a yield of 60 percent at a Ti02 grade of 0.39 percent, as well as a higher GE brightness. With the sample C of the fine raw clay, the collectors of the invention again exceeded the flotation performance of both the standard liquid resin fatty acid and AP-6493. The best performer with this crude is the collector of Example 1, the which produces the maximum reduction in Ti02 level in a comparable product yield of 61 percent. The thick raw clay D responded to the flotation of the standard liquid resin very unsatimately, which has Ti02 reduction of only 0.8 percent, with a product yield of 60 percent. The newly invented collectors, in conjunction with the commercial collector, produce much improved flotation performance compared to the standard liquid fatty acid reagent system, Both the compositions of Examples 1 and 3 produce significantly better Ti02 reductions than the collector. commercial, to 0.53 percent and 0.66 percent, but low product yields of 58 percent and 64 percent, respectively, compared to commercial collectors of 70 percent yield and 0.81 percent of Ti02. The invention described herein is well calculated to fully meet the objectives set forth above, it will be appreciated that the numerous modifications and modalities may be drawn by those skilled in the art, Therefore, it is intended that the appended claims cover all modifications and modalities that fall within the true spirit and scope of the present invention.

It is noted that in relation to this date the best method known to the applicant to carry out the aforementioned invention, is that which is clear from the present description of the invention. Having described the invention as above, the content of the following is claimed as property

Claims (7)

1. A method for the preparation of a mineral collection composition, characterized in that the method comprises: reacting an ester of a fatty acid from Ce to C22 with a hydroxylamine salt and a base in the presence of an oil and water to produce a salt of alkyl hydroxamate; then acidifying the alkyl hydroxamate salt, forming an organic layer and an aqueous layer; and separating the organic layer from the aqueous layer to provide a mineral collector composition, comprising a mixture of the C-C22 fatty hydroxamic acid and the oil.

2. The method according to the rei indication 1, characterized in that the organic layer contains a fatty hydroxamic acid of Ce to C22 substantially free of the starting esters and products of hydrolysis of the ester.

3. The process according to claim 1, characterized in that it additionally comprises the selection of the oil from the group consisting of hydrocarbon, vegetable, plant, and animal oils.

4. The process according to claim 3, characterized in that the oil is a fatty triglyceride oil.

5. The process according to claim 4, characterized in that it additionally comprises the selection of the ester from the group consisting of methyl and ethyl esters of caproic acids, enanthic acid, caprylic acid, pelargonic acid, caproic acid, undecanoic acid, lauric acid , tridecanoic acid, tridecanoic acid, myristic acid, pent adeconic acid, palmitic acid, margaric acid, stearic acid, oleic acid, benzoic acid, ethyl benzoic acid, salicylic acid, a-naphthoic acid, b-naphthoic acid, cyclohexyl carboxylic acid, and cyclopentyl carboxylic acid.

6. The process according to claim 1, characterized in that the hydroxylamine salt is a sulfate or hydrochloride salt.

7. The process according to claim 1, characterized in that it additionally comprises maintaining the organic layer at a temperature above which the hydroxamic acid solidifies.