DE2951702A1 - SEPARATION OF CALCIUM-CONTAINING MATERIAL FROM ORE - Google Patents

Description

OCCIDENTAL RESEARCH CORPORATION, 21OO Southeast Main Street, Irvine, California 92713, United States of America

Separating calcium-containing material from ore

Background of the invention

The invention relates to a method for separating calcium-containing limestone from lime ore. In particular, it relates to a method for separating calcite (CaCO ₃ ) from magnesite, ferrous rock (magnatite), chert, granite, quartz and other silicates that are present in lime ore, in particular calcium carbonate from magnesite, quartz and / or other silicates. The process can also be used to separate and recover magnesite. Magnesite is a precursor to pure magnesium

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Bremen / Bremen Office: P.O. Box / P. O. Box 10 7127 Hollerallee 32, D-2800 Bremen 1 O Telephone: (0421) »349071

Facsimile / Telecopier: Ra-.k Xerox 400 Telegr. / Cables: Diagram Eremen Telex: 244 958 bopal c

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Accounts Bremen:

Bremer Bank, Bremen

(Sort code 290 800 10) 100 144 900

Deutsche Bank, Bremen

(Sort code 290 700 50) 111 2002

PSchA Hamburc

(Sort code 200 100 20) 1260 83-202

Munich Office: Postfach / PO Box 14 01 08 Schlotthauerstraße 3, D-8000 Munich 5 Telephone: (089) 65 23 21
Telekop./Telecop .: (089) 2215 69 R X. 400 Telegr. / Cables: Telepatent Munich Telex: 523937 jus d (code: forbo)

BOEHMSRT & BOEHMEKt "

oxide valuable, its main use in high refractories Materials lies.

Limestone is a common mineral and occurs in many different concentrations in different calcareous ores. These lime ores also contain impurities such as chert, iron-containing rock (magnatite), magnesite, granite, quartz and various other silicates. Such impurities are generally referred to below as gangue. The raw extracted lime ore has to be processed to obtain the good properties of the calcium-containing limestone and in particular the lime (CaCO ₃ ) in the ore, to make limestone of the desired quality for commercial uses such as in the glass and animal feed industry to obtain. Furthermore, the limestone for use in cement production must meet certain specifications, particularly with regard to the alkaline material.

Generally, it is common to remove calcium-containing limestone from gangue by procedures that are between the physical Properties of the calcium-containing limestone and the gangue differ, separate. Closing such procedures Sorting by hand or optically sorting the lime ore. Sorting by hand is slow, laborious and economically unattractive. Optical sorting is because of the difficulties in color resolution and the difficulty to distinguish between the different shades of color in limestone and gangue rock is limited. Limestone can be improved for alkaline material by selective mining; but through such selective mining becomes a lot of limestone

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It is left undamaged and therefore cannot be used. Concentration by flotation is also related has been used to reclaim limestone, but the cost of flotation processes is relatively high and as such economically unattractive.

Summary of the invention

According to the invention, a method for separating limestone is provided higher grade of lower grade limestone and the gangue present in crushed limestone ore delivered, which has the following process steps: Treating the crushed limestone with at least a coupling agent made up of saturated and unsaturated carboxylic acids containing between about 4 to about 22 carbon atoms, which one was selected selectively coats the calcium-containing limestone in the lime ore and thereby essentially coats gangue excludes, wherein at least one fluorescent dye is provided for the coupling agent; Irradiate

/ 'of the treated crushed limestone for stimulation and inducing fluorescence of the fluorescent dye to one to distinguish the coated limestone particles higher content of the coated limestone particles lower content and the substantially uncoated gangue particles sufficient degree and separation of the high content fluorescent coated limestone particles from the coated limestone particles lower content and the non-fluorescent gangue particles.

Another method of the invention for separating

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of limestone of higher content of limestone of lower content and / or silicate-containing gangue, which in particulate! Lime ore is present, has the following steps: Treating the crushed lime ore with at least a coupling agent selected from the group consisting of aliphatic amines, between about 8 to about 22 Contain carbon atoms and beta amines that are between containing about 7 to about 21 carbon atoms, which selectively contains silicates in the gangue particles coats and the coating of the calcium-containing limestone and magnesite particles essentially. excludes along with providing at least one fluorescent dye in addition to the coupling agent; Irradiate the treated crushed lime ore to make fluorescence of the fluorescent dye one for differentiation of the coated silicate-containing particles and partly coated limestone particles of lower content from the less coated, limestone particles of higher content To stimulate and induce sufficient degrees of salary; and detaching the fluorescent, coated silicates and lower content limestone particles from the limestone particles higher salary.

After separating the silicate-containing gangue particles, the essentially non-fluorescent lime ore particles, which essentially contain little silicate-containing material, but calcium-free gangue, such as magnesite, to separate the magnesite from calcium-containing limestone, such as calcite or dolomite. In addition, magnesite can be separated from calcite and / or dolomite, whereby Calcite and / or dolomite not for the separation of silicate

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containing material has been pretreated. For example, a magnesite ore, the calcite and / or dolomite contains, by the inventive method for separation be treated by magnesite of calcite and / or dolomite.

To separate the magnesite from the calcium-containing particles, such as calcite or dolomite, the particles

^ - with a coupling agent that selectively contains calcium Coated particles treated with substantial elimination of the magnesite coating. Such a thing Coupling agent can be made up of saturated and unsaturated carboxylic acids that are between about 4 to about 2 2 carbon containing atoms. Such a coupling agent essentially coats the calcite and closes to a lesser degree - the dolomite at essentially Exclusion of the coating of magnesite. A fluorescent dye can, as described above, for Coupling agent may be provided. The particles are exposed to chemically effective radiation for the induction of

/ - ", fluorescence of the fluorescent dye to one for the differentiation of the coated and fluorescent dolomite and / or calcite in the particles of the substantially uncoated, non-fluorescent magnesite in the particles is irradiated to a sufficient degree. As described above, the particles are separated due to the difference in fluorescence.

In order to add the dye to the particles coated with coupling agent with the substantial exclusion of the uncoated To bring particles, a non-water-soluble coupling agent is used when the fluorescent

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The dye is insoluble in water. Nonetheless, a water-soluble coupling agent and a water-insoluble dye can also be used to obtain dye coupling to the coating on a selected particle. For example, a water-soluble amine coupling agent can form a coating on a substance in a mixture of particles (for example, on silicates), whereupon an oil-soluble dye such as fluoranthene in a non-reactive oil such as a paraffin oil (SAE 20 base ₍ lubricating oil The silicate particles are made hydrophobic or oleophilic with the help of the amine coating, which attracts the water-insoluble dye in oil and thereby couples the dye to the coated particles.

Water-soluble coupling agents and water-soluble paints • can be used when having a chemical bond sufficient strength to be removed during subsequent process steps, such as a subsequent one Washing step, .to prevent it from being formed during the treatment non-reactive, water-soluble dyes and water-soluble coupling agents can also be used if they are not removed in the subsequent process steps. For example, a water-soluble dye be applied at a temperature that is higher than the temperature of the subsequent steps (for example an application of hot paint and a cold wash). For example, a water-soluble Amine can be used as a coupling agent, after treating the particles with the amine forming a prepolymer Agent such as formaldehyde is added to form a prepolymer with the amine which

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upon subsequent contact with acid and / or heat, polymerizes to form a water-insoluble coating.

In order to apply the dye to particles which are not selectively coated with the coupling agent, substantially excluding coated particles, a water-insoluble coupling agent and a water-soluble dye or a water-insoluble, coupling agent and water-insoluble dye can be used. For example, a water-insoluble coupling agent such as oleic acid can be applied to a substance in a particle mixture (for example on calcium-containing limestone), then - the entire mixture is a water-soluble dye dissolved in water, such as Rhodamine B, Flavin FF or FluoresceYn derivatives ( Uranine), whereby the water-insoluble coupling agent makes the calcium-containing limestone particles hydrophobic so that the dye does not adhere, but the dye adheres to the hydrophilic, uncoated particles. In such an arrival \ f application of the method according to the invention, a relatively weak air flow are used to small drops of water soluble Farbe.von the hydrophobic particles to be removed, whereby a subsequent washing step can be avoided in the process. The washing step can be omitted _f when the concentration of the coupling agent and the dye is sufficiently low even when carrying out the method according to the invention.

Of course, the principles described herein to be used, limestone of higher content

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to separate from limestone of lower content, since the limestone particles of higher content have a higher fluorescence intensity than the limestone particles have lower content. The limestone particles of higher content and lower Content can be separated by setting the sorting device to read these particles accepts the fluorescence above a certain show the minimum intensity range and those particles which have no or only a fluorescence below this emit minimum intensity range, discards.

Detailed description of the invention

According to the invention, a method for separating calcium-containing Limestone supplied from gangue contained in lime ore in order to convert calcium-containing limestone values from it to win. The term "limestone" is used hereinafter to refer to calcium-containing limestone, such as Calcium carbonate, calcite, dolomite and other calcium carbonate containing. or similar minerals. The term "lime ore" is used hereinafter to refer to lime-containing ores which other material than calcium-containing limestone, for example magnesite, silicate-containing material and the like, to designate what has already been generally defined as "gait" above. The phrase "separating the Ganga limestone includes the separation of higher grade limestone from lower grade limestone just like cutting off the limestone from gangue. By the terms "higher grade limestone" and "limestone lower grade "is a relative distinction in calcium carbonate content between the two classes

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by limestone, that is, between calcite and dolomite. Such relative distinction may be variable depending on the reason for the distinction between different classes of limestone, such as the classification of limestone according to its numerous end uses. The implementation of the inventive method comprises the selective coating of either the limestone or gangue or, more precisely the CaCO., Or the silicates in the lime ore with a coupling agent or a mixture of coupling agents with which a fluorescent dye is combined, then irradiating the Lime ore with electromagnetic radiation _t to fluoresce the fluorescent color on the treated, selectively coated particles. The fluorescent material is then separated from the essentially non-fluorescent material. The method according to the invention is based on the differences in surface properties of the various materials present in lime ore to accept coupling agents and dyes attracted by them or to repel them. Because of these differences, a coupling agent or mixture of coupling agents can be selected that will effectively and selectively coat only the limestone or gangue. Surface properties are relatively more consistent than other properties such as color, reflection, or conductivity. These other properties tend to be similar so that a high degree of resolution is necessary to distinguish between the materials. Such a degree of resolution is difficult to obtain and accordingly the efficiency of separation based on these properties suffers. Separation of material due to surface properties is therefore

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more consistent than procedures based on the other above Properties are based.

In order to distinguish between the material coated with coupling agent and the uncoated material, in a labeling agent such as a fluorescent dye incorporated into the coupling agent or incorporated into the labeling material like a fluorescent dye added through the coupling agent is repelled. The ore can then be irradiated with electromagnetic radiation to remove the Bringing dye to fluorescence. The dye, combined with the coupling agent coating, of the parts of the Material coats, fluoresces, and the essentially uncoated material does not fluoresce in any way substantial extent. On the other hand, if the dye is repelled by the coupling agent, they do not show particles coated with coupling agent fluorescence, while the particles coated with coupling agent do not fluoresce to any substantial degree. Because of the different materials can then be separated.

In general, fluorescence refers to the ability to absorb radiation of a certain wavelength and Simultaneously re-emitting light of a different wavelength, as long as the excitation takes place. In the method according to the invention, the term "fluorescence" is related to the property of absorbing radiation of a certain wavelength and absorbing it at a different wavelength Re-emitting wavelength, visible or not, during or after exposure to active excitation Suspend these or both periods

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Fluorescence is used here as a generic term, which includes fluorescence, phosphorescence and the emission of electromagnetic radiation, regardless of whether these are inside or outside the visible spectrum.

Electromagnetic radiation refers s ~ _Λ generally to the transmission of energy waves of all different wavelengths, the electromagnetic the entire spectrum are encountered. In the method according to the invention it is provided that the term "electromagnetic radiation" is used to denote any and all stimuli which excite and will cause fluorescence of the fluorescent dye. "Electromagnetic radiation" is therefore used as a generic term to denote electromagnetic radiation and all other stimuli that excite and will cause fluorescence of the fluorescent dye.

When carrying out the method according to the invention at () Lime ore, the ore is first subjected to a crushing step. In this shredding step, that becomes Ore crushed to physically separate the limestone from the gangue present. Shredding increases that Surface area of the particles and provides a greater surface area and reaction site for coating the particles by the coupling agent · The lime ore is reduced to a particle size of between about 0.635 cm to about Chopped 20.32 cm (about 0.25 inches to about 8 inches). Particle sizes of less than 1/4 inch can be used are used in the implementation of the method according to the invention, nevertheless require such

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Sizes larger amounts of the coupling agent and are more difficult to separate. Particle sizes greater than 8 inches (20.32 cm) can also be used in carrying out the process of the invention, but generally include Impurities in such a way that the separation efficiency decreases. Ore particles of between about 1.27 are preferred to about 7.62 cm (about 0.5 inch to about 3 inches). Subsequent to the comminution and classification (" ! Steps, the lime ore particles can be desludged, to remove soluble contaminants and surface dust on the particles.

The method according to the invention is carried out with lime ore, in which the lime ore after grading with a coupling agent or a mixture of coupling agents which selectively adheres to limestone or the gangue present in the lime ore. That is preferred Lime ore is treated with a coupling agent or mixture of coupling agents that selectively remove the limestone coat in ore. Coupling agents that are selective for limestone (i.e., calcium-containing material) more selective than gait coupling agents. Coupling agents that act selectively for gait are accordingly less efficient when used to separate the limestone from the gangue as coupling agents, that are selective on limestone.

For use in practicing the invention Process suitable coupling agents for coating calcium-containing Material that is present in the lime ore particles can consist of saturated and unsaturated carboxylic acids be selected, including fatty acids,

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which are between about 5 to 22 carbon atoms, or one Mixture of the same. Usable carboxylic acids include palmitoleic acid, oleic acid, linoleic acid, Caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, peanut acid, benzic acid, Tall oil fatty acids and the like. At least one carboxylic acid is preferably used, which is between about Has 8 to 18 carbon atoms. Carboxylic acids that contain more than 22 carbon atoms can be related however, tend to be less selective in general, and therefore both limestone and gangue particles to cover. Carboxylic acids with fewer than 5 carbon atoms generally do not have the ability to to coat any particles in a significant amount. In general, the preferred carboxylic acid occurs enters into a chemical reaction with the calcium present, for example oleic acid reacts to form calcium oleate away.

For coating the silicate-containing gangue in lime ore is a coupling agent of aliphatic amines or a Mixtures thereof selected containing between about 8 to about 22 carbon atoms and beta amines or Mixtures thereof containing between about 7 to about 21 carbon atoms. Aliphatic amines that are beneficial can be used in the ^ process according to the invention include octylamine, decylamine, dodecylamine, Tetradeoylamine, hexadecylamine, octadecylamine, eicosanylamine, Docosanylamine and the like. Beta amines can be commercially available beta amines such as armies L-7 to L-15 series' (registered trademarks), products from Armak Chemicals, include and are the

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Known to those skilled in the art. In general, amines containing more than 22 carbons are not as selective as amines, that have fewer than about 22 carbon atoms. Aliphatic Amines with less than about 8 carbon atoms and beta- Amines having fewer than about 7 carbon atoms generally do not have the desired coating-forming properties. Preferred is an aliphatic amine containing between about 10 to about 18 carbon atoms and a beta Amine containing between about 7 to about 15 carbon atoms. Among the amines, the beta "amines are more selective for silicates as calcium-containing materials and are therefore preferred. It can also be a water soluble one Amine coupling agent selected from the water-soluble ones Salts of the aliphatic and beta amines identified above can be used.

A fluorescent dye is used with the Coupling agents combined to treat the lime ore. The fluorescent dye can interact with the coupling agent be brought together either before or after treating the ore. Fluorescent dyes are known to the person skilled in the art, those which are compatible with the coupling agents can be used when carrying out the method according to the invention can be used. Preferably, water-insoluble fluorescent dyes are used when a water-insoluble one Coupling agent is used. Water-soluble, fluorescent dyes can be found in aqueous dispersants dissolve during the pretreatment step, and therefore fluorescent properties, of essentially all particles notify you when their surface is covered with an aqueous layer.

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Usable fluorescent dyes may include fluoranthene, fluorescent yellow G, a product of Morton Norwich Chemical Co., rhodamine B, flavin FF, fluorescein derivatives (uranine), and the like. The fluorescent dye can be used in any form such as a solution, suspension, emulsion, dispersion or alone. The fluorescent dye can be used with the coupling agent ^: before treating the ore by admixing the fluorescent dye with the coupling agent or by mixing the fluorescent dye with a suitable diluent or solvent such as an oil and then mixing it with the coupling agent. The fluorescent dye has an affinity for the coating of coupling agent and is therefore preferably only entrained in the coated ore particles. Any dye adhering to uncoated particles is generally removed by a water wash. Preferably the coupling agent and the fluorescent dye are mixed prior to treating the ore. Such a pretreatment requires fewer fluorescent dye and fewer process steps and is therefore generally more efficient, both from an economic point of view and from the point of view of the separation results.

Following the crushing and classification of the lime ore, the ore is treated with the coupling agent. the Treatment of the ore with the coupling agent is accomplished by contacting the sized ore with the coupling agent. The coupling agent can be in any suitable Way, such as to be used in solution, dispersion or alone. A dispersion of the coupling agent is preferred

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agens formed in water. Many methods of bringing the ore into contact with the aqueous solution are available and known to the person skilled in the art. Such methods include spraying an aqueous dispersion on the sized Ore, then passing the ore through a dispersion bath and the like. The classified one is preferred Ore sprayed with an aqueous dispersion. Spray techniques include, but are in no way limited to spraying the dispersion on the ore when this ore passes the spray nozzle on a vibrating screen or belt, or Spraying the ore as it passes through a ring or series of ring sprayers.

Afterward . after spraying the ore with aqueous solution, the ore is cleaned with a suitable detergent, such as water, rinsed to wash away excess dispersion from the ore and such dispersion that is physically entrained in the ore particles. The coupling agent remains, along with the fluorescent one Dye selectively on the coatings of the particles for which there is a preference due to the surface properties this particle has. The coated particles are capable of fluorescence when they are electromagnetic Radiation to be irradiated. Since tying agents have preferences, they selectively override either the limestone or gangue in the lime ore. The ore particles that are not coated fluoresce generally not to the same extent as the coated particles.

Subsequent to the treatment of the lime ore is the ore

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exposed to electromagnetic radiation to fluoresce the coating on the particles. The coated fluorescent particles can be separated by any convenient means, such as by hand, by optical sorting devices, and by a device as described in Mathews ¹ US Pat. No. 3,472,375. In such a facility, free-falling ore mix passes a series of detectors. With suitable amplification, each detector is able to differentiate between non-fluorescence and fluorescence or intensities of fluorescence. Each detector in turn controls a jet of liquid that is selectively directed transversely to the path of the falling particle. The jet of liquid may only hit the ore particles that are emitting correctly. The directed liquid jet directs the ore particles in a divergent path, whereby these are separated from the undesired ore particles. Such a device is suitable for separating the particles coated with coupling agent and dye from the uncoated particles.

The invention will now be explained further in the following by means of examples, which are in no way intended to be limiting.

Example I.

A lot of crushed lime ore made up of 47.5 Weight percent limestone having an average particle size of about 1,905 cm (3/4 inch), which is primarily Limestone, chert, iron-containing rock, granite, quartz and various other silicates containing it was made using a coupling agent of oleic acid combined with fluoranthene treated as a fluorescent dye. The olein

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acid had been combined with fluoranthene by dissolving the fluoranthene in oil (for example SAE 20 base lubricating oil with no additives) and mixing it with oleic acid. E: An aqueous dispersion of oleic acid together with fluoranthene was prepared. This aqueous dispersion would be sprayed onto the crushed and classified ore. The coupling agent, oleic acid together with fluoranthene selectively coated the limestone particles and was (J) repelled by the gangue particles in the ore. The excess aqueous dispersion was washed off the ore with a water wash.

The coated limestone particles were separated from the uncoated gangue particles using a Mathews ¹ separator by dropping particles of the ore freely in front of an electromagnetic radiation source and then in front of fluorescence detectors. The coated limestone particles fluoresced to a much greater extent than the gangue when irradiated. Each detector had been amplified to detect fluorescence from the coated particles and each controlled a jet of liquid that was selectively directed transverse to the path of the falling particles. The jet of liquid only hit the fluorescent ore particles. The directed jet of liquid directs the fluorescent limestone particles onto a path that diverges from that of the freely falling gangue particles.

The separated limestone particles contained 94.3% limestone, a 93.7% recovery of the in the could original raw material contained limestone

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can be achieved.

Example II

The procedure of Example I was repeated in all essential details except that the lime ore became a Particle size of about 3.81 cm (1.5 inches) was crushed and that. Coupling agent caprylic acid in common

/ - χ was with fluoranthene as the fluorescent dye. the Caprylic acid selectively coated the limestone particles and was repelled by the gangue. The originally used Lime ore contained 77.8% by weight limestone. The fluorescent limestone particles produced by the non-fluorescent Ganga particles separated contained 99.5% limestone.

The limestone particles produced by the process of the invention were extracted, was 88.9% of the limestone present in the starting material.

Example III

- 'The procedure of Example I was followed in all essentials Details repeated. The initial limestone concentration in the ore was 45.1 wt% and the limestone concentration in the recovered fluorescent limestone particles was 95%. The entire, by the invention Limestone obtained by the method was 87% of that contained in the starting material.

Example IV

The procedure of Example I was repeated in all essential details except that the initial lime ore to a particle size of between 1.27 to 6.35 cm

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(0.5 to 2.5 inches) and the coupling agent ARMEEN L-9, a trademark Armak Chemicals product, which is a beta-amine containing 9 carbon atoms. That ARMEEN L-9 coupling agent was combined with fluoranthene as a fluorescent dye. The ARfIEEN L-9 Coupling agent selectively coated the silicate-containing Ganges species in the lime ore.

The initial lime ore contained 25.13% by weight of silicates, 0.93% by weight of _{FeO 3} , 35.65% by weight of CaO and 1.07% by weight of K ₃ O. The non-fluorescent ones Limestone particles separated by the process according to the invention contained 1.07% by weight of silicates, 0.23% by weight of Fe ₂ O ₃ / 53.12% by weight of CaO and 0.12% by weight of K_0. The fluorescent, separated gangue contained 42.99% by weight of silicates, 1.45% by weight of Fe ₃ O ₃ , 22.77% by weight of Cao and Ί, 79% by weight of K ₂ O.

ARMEEN L-11 and ARMEEN L-15 can also try this example IV can be used, nevertheless C the ARMEEN L-9 has heke-re selectivity for silicates versus calcium carbonate.

Example V

The procedure of Example I was repeated in all essential details, except that the lime ore used ground to a particle size of 1.27 to 6.35 cm (0.5 to 2.5 inches) for pretreatment the ore related coupling agent was tall oil fatty acid combined with fluoranthene dye. The tall oil fatty acid Coupling agent selectively coated the limestone and

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caused the limestone particles to fluoresce when exposed to electromagnetic radiation.

The lime ore originally used contained 5.04% by weight of silicates, 0.24% by weight of Fe ₃ O ₃ , 51.14% by weight of calcium oxide and 0.16% by weight of K ₃ O. The after The fluorescent limestone particles separated by the process according to the invention contained 0.53% by weight of silicates, 0.13% by weight of Fe ₃ O ₃ , 53.58% by weight of CaO and 0.95% by weight of K ₃ O. Die The non-fluorescent, separated gangue contained 10.39% by weight of silicates, 0.38% by weight of Fe ₃ O ₃ , 45.82% by weight of CaO and 0.28% by weight of K ₃ O.

Example VI

The procedure of Example V was followed in all essentials Details repeated.

The lime ore used contained 11.95% by weight of silicates, 0.6% by weight of Fe ₃ O ₃ , 46.6% by weight of calcium oxide and 0.05% by weight of K ₃ O Limestone particles separated by the method contained 5.65% by weight of silicates, 0.4% by weight of Fe ₃ O ₃ , 50.15% by weight of calcium oxide and 0.93% by weight of K "0". The non-fluorescent gangue that was separated contained 42.70% by weight of silicates, 1.53% by weight of Fe ₃ O, 29.52% by weight of CaO and 0.05% by weight of K ₃ O .

Example VII

The procedure of Example IV was repeated in all essential details.

The starting lime ore contained 8.89% by weight of silicates, 0.34% by weight of Fe ₃ O ₃ , 47.52% by weight of CaO and 0.68% by weight of K ₃ O.

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The non-fluorescent limestone particles separated from the gangue by the process _{according to the invention contained 0.55% by weight of silicates, 0.1% by weight of Fe 2} O ₃ , 53.73% by weight of CaO and 0.04% by weight. % K ₃ O. The fluorescent gangue particles contained 24.18% by weight of silicates, 0.77% by weight of Fe ₃ O ₃ , 36.51% by weight of CaO and 1.8% by weight of K ₃ O.

Example VIII

The procedure of Example IV was repeated in all essential details except that decylamine was chosen as the coupling agent. The decylamine coupling agent coats selectively silicate-containing gangue that is present in lime ore. The gait particles become fluorescent separated from the non-fluorescent gait particles.

Example IX

The procedure of Example IV is repeated in all essential details except as the coupling agent n-dodecylamine is chosen. The n-dodecylamine coupling agent Selectively coats gangue containing silicate that is present in the lime ore.

The fluorescent gait is different from the non-fluorescent Limestone particles separated.

The inventive method, which carboxylic acids as Coupling agent used can also be used to separate calcite from magnesite and dolomite from magnesite. The terms "separating the magnesite from calcite and / or dolomite" include the separation of higher-grade magnesite of lower-grade magnesite as well as separating

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. of magnesite and / or calcite and / or gangue dolomite. By the terms "higher grade magnesite" and "Lower grade magnesite" becomes a relative distinction of the magnesium carbonate content of two Grades of magnesite addressed. Such a relative distinction can be made depending on the reason for the distinction, to distinguish between the magnesite classes, be variable, for example from dividing the magnesite into classes depending on the numerous end uses of the magnesite.

When carrying out the method according to the invention with respect to an ore containing magnesite and calcite and / or dolomite, the ore is first subjected to a crushing step. In this crushing step crushed the ore to physically separate the magnesite from the other material. Crushing increases the Surface of the particles and provides a larger surface and reaction surface for the coating of the particles through the coupling agent. The ore is preferred to have a particle size of between about 0.635 cm to about 20.32 cm (about 1/4 inch to about 8 inches). Particle sizes less than 0.635 cm (1/4 inch) can also be used of the method according to the invention can be used, nonetheless such sizes require higher amounts of coupling agent and are more difficult to separate. Particle sizes greater than 20.32 cm (8 inches) can be used in the method of the invention, but drag generally impurities with it, so that the separation efficiency decreases. Ore particles of between are preferred about 1.27 to about 7.62 cm (1/2 inch to about 3 inches). After the crushing and classification steps

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The ore particles can be desludged to remove soluble impurities and remove surface dust from the particles.

In relation to magnesite ore, the process is carried out as follows: that first the ore after classification with a coupling agent or a mixture of coupling agents, which selectively adhere to the magnesite or the dolomite and / or calcite in the ore is prepared. Is preferred The ore is prepared with a coupling agent or a mixture of coupling agents that selectively remove the calcite and / or coat dolomite in the ore.

When carrying out the method according to the invention useful coupling agents coat the calcite and / or dolomite in the magnesite ore particles and can be obtained from saturated and unsaturated carboxylic acids, which are fatty acids containing between about 5 to about 22 carbon atoms, or have a mixture thereof. Carboxylic acids that can be used include palmitoleic acid, Oleic acid, linoleic acid, caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, Stearic acid, peanut acid, benzic acid, tall oil fatty acid ^ n and the like. At least one carboxylic acid which contains between about 8 to about 18 carbon atoms is preferably used. Carboxylic acids that are more than about 22 carbon atoms can be used, but generally tend to be less selective and therefore to coat both limestone and gangue particles. Carboxylic acids with less than 5 carbons Atoms generally do not have the property of

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which of the particles to coat. In general, the preferred carboxylic acid goes along with a chemical reaction calcium carbonate or calcium magnesium carbonate, for example oleic acid reacts to calcium oleate.

A fluorescent dye is used for preparation of the ore used coupling agents combined. The fluorescent dye can interact with the coupling agent can be combined either before or after treating the ore. Fluorescent dyes that interact with the Coupling agents tolerated and those described above can be used. When carrying out the procedure in the case of magnesite ore the fluorescent dye will be like described above for lime ore.

After the magnesite ore has been crushed and classified, the ore is pretreated with the coupling agent. The pre-treatment the ore with the coupling agent is achieved by contacting the classified ore with the coupling agent. The coupling agent can be in any suitable form Form, such as in solution, in dispersion, or alone, can be used. A dispersion is preferred of the coupling agent formed in water. Methods of contacting include spraying the aqueous dispersion on the classified ore, then passing the ore through a dispersion bath and the like. Preferred the classified ore is sprayed with the aqueous dispersion. Spray techniques include, but are in no way limited to spraying the dispersion onto the ore when this is the spray nozzle on a vibrating Umbrella or band happening, or spraying the ore when it passes through a ring or series of ring sprayers runs.

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After spraying the ore with the aqueous dispersion, the ore is washed with a suitable washing agent, such as water ₍ to remove excess dispersion from the ore and any dispersion physically entrained in the ore. A fine jet of air can also be used to remove entrained dispersion. The coupling agent combined with the fluorescent dye remains selectively on the coatings of the particles for which it has a preference due to the surface properties of the particles, and the coated particles are capable of fluorescence when irradiated with electromagnetic radiation.

Following treatment of the ore, if the attached dye or pigment is fluorescent, the Ore exposed to electromagnetic radiation to fluoresce the coating on the particles. The overdone, fluorescent particles can be caused by any usual Means are separated, for example by hand, by optical sorting devices and by devices such as they are described in Mathews US Pat. No. 3,472,375.

The invention will now be described below on the basis of further examples, which are by no means limiting should be understood.

Example X

A synthetic sample of calcite and magnesite particles approximately 1.27 cm (1/2 inch) in size was used to remove Washed surface contaminants. The amount of calcite to magnesite in the sample was in a ratio of 1: 1. To The sample was desludged with an aqueous suspension of about 2% oleic acid, in which about 2% is fluorescent

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Dye, fluoranthene, were dissolved, pretreated. It turned out a good, fluorescent coating on calcite and a poor coating on magnesite. Due to the different fluorescence under ultraviolet light became magnesite (non-fluorescent) from calcite (fluororescent) severed.

Example XI

A synthetic sample of dolomite and magnesite in a ratio of 1: 1 was desludged. The particle size of Dolomite and magnesite was about 1.27 cm (1/2 inch). After desludging, the material was washed with an aqueous solution pretreated with about 2% oleic acid in which about 2% fluoranthene had been dissolved. It turned out to be a good fluorescent one Preserved coating on dolomite. A poor coating was obtained on magnesite. The intensity differences of the fluorescence were determined by washing the Materials improved with water. Separating the dolomite (fluorescent) from magnesite (non-fluorescent) was made achieved under ultraviolet light.

The method according to the invention can also be used in optical, non-fluorescent separation processes are used, by substituting the fluorescent dye described here with a dye that has a certain color within the visible spectrum.

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Claims (30)

- 9Λ - BQEHMEKT & BQEHMERT O 201 CLAIMS 1. Process for separating calcium-containing material from non-calcium-containing, silicate-containing material including material, in a particulate ore, characterized by the following steps: a) Treat. of the particulate ore with an r . Coupling agent selected from the group consisting of from: at least one carboxylic acid containing between about 4 to about 22 carbon atoms, selected from saturated and unsaturated carboxylic acids, for the selective coating of calcium-containing substances Particulate ore material with substantial exclusion of coating of silicate-containing; at least one aliphatic containing between about 8 to about 22 carbon atoms Amine, for the selective coating of silicate-containing material in particulate material _ with substantial exclusion of overstressing of calcium-containing; and at least one, between 823 030605/0052 -: 3ÖEHMERTÄ BOEHMERT Beta-amine containing from about 7 to about 21 carbon atoms for selective coating of silicate-containing material in particulate! Ore at im
substantial elimination of calcium-containing coating; b) providing at least one labeling agent for the coupling agent; and c) separating the material coated with the coupling agent from the material not coated with the coupling agent. 2. The method according to claim 1, characterized in that the marking agent is a coloring agent. 3. The method according to claim 1, characterized in that the marking agent is a fluorescent dye and that treated particulate material with electromagnetic radiation to cause the fluorescence of the fluorescent Dye is irradiated. 4. The method according to claim 3, characterized in that the fluorescent dye from the group consisting of fluoranthene, fluorescent yellow G (fluorescent yellow
G) and mixtures thereof. 5. The method according to claim 1, characterized in that the calcium-containing material of magnesite by selection
a coupling agent having at least one containing between about 4 to about 22 carbon atoms
Carboxylic acid, selected from saturated and unsaturated, - 2 - 030605/0052 capable of selective coating of calcium-containing material with substantial elimination of coating of magnesite. 6. The method according to claim 1, characterized in that the particulate lime ore has a particle size of between from about 0.635 to about 20.32 cm (1/4 inch to 8 inches). 7. The method according to claim 6, characterized in that the particulate lime ore has a particle size of is between about 1.27 to about 7.62 cm (about 1/2 to about 3 inches). 8. The method according to claim 1, characterized in that the labeling agent is added to the coupling agent prior to treating the ore. 9. The method according to claim 1, characterized in that the labeling agent for the coupling agent after treatment of the ore is given. 10. The method according to claim 1, characterized in that that the labeling agent is oil-soluble. 11. Process for separating high-grade limestone from low-grade limestone and gangue, from particulate! Lime ore characterized by treating the particulate lime ore with at least one coupling agent selected from saturated or unsaturated between about 4 to about 22 carbon atoms having carboxylic acids, the coupling agent being selective on the calcium carbonate in limestone with essentially the exclusion of the 0 30605/0052 Coating of gait forms a coating with the simultaneous provision of at least one fluorescent Dye for coupling agent; Irradiating the treated particulate limestone to excite and induce the fluorescence of the fluorescent dye to a high level for distinguishing the coated limestone ('■ Content of the coated limestone of low content and the substantially uncoated gangue particles in sufficient degrees; and separating the fluorescent coated limestone particles of higher content from the limestone particles of lower content and the non-fluorescent gait particles. 12. The method according to claim 11, characterized in that that the coupling agent has at least one carboxylic acid having between about 8 to about 18 carbon atoms is. 13. The method according to claim 11, characterized in that ν that the coupling agent is oleic acid. 14. The method according to claim 11, characterized in, that the coupling agent is caprylic acid. 15. The method according to claim 11, characterized in that the coupling agent is a tall oil fatty acid. 16. Process for separating higher-grade limestone from lower-grade limestone and / or silicate-containing Gait from particulate lime ore, marked ~~ by the following steps: Treating the particulate 030605/0052 & ÖBHMERT 'St B.GE ^ MERT Lime ore having at least one of the group consisting of the aliphatic, from about 8 to about 22 carbon atoms containing amines and the selected coupling agent containing between about 7 to about 21 carbon atoms beta amines that selectively remove the silicates in the gangue particles with substantial elimination of calcium carbonate particle coating coated, combined with the provision of at least one fluorescent dye for the coupling agent; Irradiating the treated particulate lime ore for exciting and causing the fluorescence of the fluorescent dye to one for differentiation of the coated gangue particles and the partially coated limestone particles of lower content from the less coated limestone particles of a higher grade; and separating the fluorescent coated ones Gangue and limestone particles of lower content from the limestone particles of higher content. 17. The method according to claim 16, characterized in that r \ that the coupling agent is an aliphatic amine is at least containing between about 8 to about 22 carbon atoms. 18. The method according to claim 17, characterized in that that the aliphatic amine is n-dodecylamine. 19. The method according to claim 16, characterized in that that the coupling agent is at least one beta amine containing between about 7 to about 21 carbon atoms. 20. The method according to claim 16, characterized in that 030605/0052 ·: SCEHMERT: & BOEHMERT W W W V W W - WWW «<C ww - ν that the aliphatic and / or beta-amine coupling agent is provided in the form of a water-soluble salt of such an aliphatic and / or beta-amine. 21. Process for separating higher grade magnesite of magnesite lower grade dolomite and / or calcite from particulate ore, characterized by following steps: a) treating the particulate ore with at least one coupling agent selected from those saturated or unsaturated containing between about 4 to about 22 carbon atoms Carboxylic acids, the coupling agent selectively coating the calcite and / or dolomite in the ore, with substantial exclusion the plating of magnesite, wherein at least one fluorescent dye is provided for coupling agent; b) irradiating the treated particulate ore for fluorescence of the fluorescent dye one for distinguishing the essentially uncoated magnesite particles high content from the more heavily coated magnesite of higher content and the much stronger coated dolomite and calcite particles to a sufficient degree and separate the magnesite particles high content of the coated magnesite particles of lower content, calcite and dolomite particles. 030605/00 5 2 3GEHfcERT ^: & BOEHMERT 22. The method according to claim 21, characterized in that the coupling agent is at least one carboxylic acid, which contains between about 8 to about 18 carbon atoms. 23. The method according to claim 21, characterized in that the coupling agent is oleic acid. 24. The method according to claim 11, 16 or 21, characterized in that that the particulate lime ore has a particle size of between about 0.6096 cm to about 20.32 cm (about 1/4 inch to about 8 inches). 25. The method according to claim 24, characterized in that the particulate lime ore has a particle size of is between about 1.27 to about 7.62 cm (about 1/2 to about 3 inches). 26. The method according to claim 11, 16 or 21, characterized in that that the fluorescent dye is added to the coupling agent prior to treating the ore. 27 The method according to claim 11, 16 or 21, characterized in that that the fluorescent dye is added to the coupling agent after treating the ore. 28. The method according to claim 11, 16 or 21, characterized in that that the fluorescent dye is oil-soluble. 29. The method according to claim 11, 16 or 21, characterized in that that the flyorescent dye from the group consisting of fluoranthene, fluorescent yellow G (fluorescent yellow G) and mixtures thereof. 030605/0052 '; BQEHNtERT ^ BQEHMERT 30. The method according to claim 1, characterized in that that the particulate ore first with a coupling agent selected from the group consisting of at least an aliphatic amine containing between about 8 to about 22 carbon atoms and at least one between Beta-amine containing about 7 to about 22 carbon atoms is treated to selectively contain silicate-containing material in particulate ore with substantial exclusion of plating non-silicate material to plating; Separating the coated, silicate-containing from the im essential coating-free, non-silicate-containing material; Treating the silicate-free material thus obtained with a coupling agent selected from the group consisting of at least one between about 4 to about 22 carbon Atoms containing carboxylic acid, selected from the saturated and unsaturated carboxylic acids, for the selective coating calcium-containing material in particulate ore with substantial exclusion of the coating Calcium-free material; and separating the coated calcium-containing material from the substantially coating-free, Calcium-free material. 030605/0052