RU2575191C2 - Improvement of electrostatic separation in ore dressing - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to ore dressing with the help of electrostatic separation. In compliance with claimed process, mineral substrate is mixed with reagent for modification of the fluid electrostatic properties to get the suspension whereat at least one mineral component and/or non-conducting mineral component is electrostatically modified. Obtained suspension is dried and electric field is applied to the dry mix. At least the portion of electrostatically modified component is separated from said dry mix. Reagent for modification of the fluid electrostatic properties is selected from the group of some chemical compounds.

EFFECT: higher efficiency of separation.

30 cl, 4 tbl

Description

State of the art

FIELD OF THE INVENTION

The present invention relates to the field of separation of certain mineral components of ore from its other mineral components using electrostatic separation.

Specifically, the present invention relates to reagents for modifying electrostatic properties and to their use in an electrostatic separation method for separating mineral ore components with improved efficiency.

Description of the Related Art

The processing and refining of many types of mineral ores, including mineral sands, sometimes known as enrichment, typically involves the separation of certain mineral components from other mineral components.

For example, a single ore or mineral sand may typically contain both rutile and zircon. Both of these minerals have independent uses and must be separated from one another. Such mineral sand may also contain ilmenite, monazite, quartz, staurolite and leucoxene, which should also be separated from rutile and zircon. Electrostatic separation is widely used in the industry of heavy mineral ores or sands. An electrostatic separator applies a voltage, generally between 21 and 26 kV, to the ore, whereby conductive components such as rutile and ilmenite migrate to one edge of the separator, and non-conductive components such as zircon migrate to the opposite edge of the separator . The stream of crushed ore or mineral sand is divided into two streams, and each stream can be further processed to separate their respective components using, for example, magnetic separation. Although electrostatic separation is an effective method, it is not considered particularly effective.

US patent No. 4131539, Ojiri, et al., Describes a method for removing small amounts of rutile from zircon sand. This patent speaks of heat treatment of zircon sand in a non-oxidizing atmosphere to change the surface electrostatic properties of rutile, which is said to make rutile more conductive, and heat-treated sand is separated more easily by electrostatic separation with a decrease in the content of titanium dioxide in the sand. Although such heating or firing can be effective, it is energy intensive and changes the surface properties of the mineral components, which may be undesirable in subsequent applications.

US Pat. No. 5502118, Macholdt et al., Teaches the use of polymer salts that are useful as charge control agents and charge enhancing agents in electrophotographic toners and developers, in triboelectrically or electrokinetically sprayed powder coatings, in electrical materials, and for electrostatic separation of polymers and mineral salts. However, this does not apply to improving the separation of mineral components.

In one mineral separation process, such as that shown in US Pat. No. 6,168,029, Henderson et al., Which relates to an increase in process efficiency, use anionic acrylic acid copolymers and acrylamide reagents. Thus, there remains a need for an improved, more efficient reagent and method for separating the conductive mineral components from the non-conductive mineral components of ordinary ore or mineral sand. Such improved separation could be used not only in the mining of rutile and zircon, but also in any other ore that contains both non-conductive and conductive components of commercial value.

SUMMARY OF THE INVENTION

The present invention satisfies the above and other needs by creating in one of the embodiments of the method of enrichment of the mineral substrate by electrostatic separation of the dry mixture containing a conductive component and a non-conductive component, including:

mixing the mineral substrate and the electrostatic modifier to form a mixture, where at least one of said conductive component and said non-conductive component is electrostatically modified; and

applying an electric field to the mixture so as to at least partially separate the electrostatically modified component from the mixture;

where the electrostatic modifier contains

an organic compound selected from the group consisting of quaternary amines; imidazoline compounds; dithiocarbamate compounds; pyridine compounds; pyrrolidine compounds; conductive polymers, polyethyleneimines; compounds of formula (IV):

(IV) R- (CONH-OX) _n

where n in the formula (IV) is 1-3; where R in the formula (IV) contains from 1 to 50 carbon atoms; and where each X in formula (IV) is individually selected from the group consisting of H, M and NR ′ ₄ , where M is a metal ion and R ′ is individually selected from the group consisting of H, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₀ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C ₁₈ naphthylalkyl;

compounds of formula (VI):

,

,

where R ₈ in formula (VI) is selected from H, C ₁ -C ₂₂ alkyl, C ₆ -C ₂₂ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C ₁₈ naphthylalkyl, X in formula (VI) is selected from the group consisting of H, M and NR ' ₄ , where M is a metal ion and R' is individually selected from the group consisting of H, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₀ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C ₁₈ naphthylalkyl;

and mixtures thereof.

In addition, the present invention relates to a method for enriching a mineral substrate by electrostatic separation of a dry mixture containing a conductive component and a non-conductive component, comprising the steps of:

mixing the mineral substrate and the reagent to modify the electrostatic properties to form a mixture, where at least one of said conductive component and said non-conductive component is electrostatically modified; and

applying an electric field to the mixture so as to at least partially separate the electrostatically modified component from the mixture;

where the reagent for modifying the electrostatic properties comprises at least one electrostatic modifier and a plurality of particles having an average resistivity that is equal to or greater than the resistivity of the non-conductive component when the non-conductive component is electrostatically modified and / or a plurality of particles having average resistivity that is equal to or less than the resistivity of the conductive component when the conductive component is electrostatically odifitsirovannym.

In another embodiment, the electrostatic modification reagent comprises an electrostatic modifier and a plurality of particles, each of these particles having a resistivity that is equal to or greater than the resistivity of the non-conductive component when the non-conductive component is electrostatically modified, or a plurality of particles having specific resistance that is equal to or less than the resistivity of the conductive component when the conductive component is electric rostaticheski modified.

In another embodiment, the electrostatic modification reagent comprises an electrostatic modifier, preferably an organic compound, and a plurality of particles, each of these particles having a resistivity that is equal to or greater than the resistivity of the non-conductive component when the non-conductive component is electrostatically modified, and / or a plurality of particles having a resistivity that is equal to or less than the resistivity of the conductive component and when the conductive component is electrostatically modified. The organic compound may be a polymer or non-polymer. In another embodiment of the present invention, the reagent for modifying the electrostatic properties comprises a polymer and a plurality of particles, each of these particles has a resistivity that is equal to or greater than the resistivity of the non-conductive component when the non-conductive component is electrostatically modified and / or a plurality of particles, having a resistivity that is equal to or less than the resistivity of the conductive component when the conductive component is an electrostat personally modified.

In another embodiment of the present invention, the electrostatic modification reagent comprises an organic, polymeric or non-polymeric compound selected from the group consisting of quaternary amines; imidazoline compounds; dithiocarbamate compounds; pyridine compounds; pyrrolidine compounds; conductive polymers such as polypyrroles, polythiophenes and polyanilines; polyethyleneimines; compounds of formula (IV):

(IV) R- (CONH-OX) _n

where n in the formula (IV) is 1-3; where R in formula (IV) contains from 1 to 50 carbon atoms and where each X in formula (IV) is individually selected from the group consisting of H, M and NR ′ ₄ , where M is a metal ion and R ′ is individually selected from a group consisting of H, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₀ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C _1S naphthylalkyl;

compounds of formula (VI):

,

,

where R ₈ in formula (VI) is selected from H, C ₁ -C ₂₂ alkyl, C ₆ -C ₂₂ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C ₁₈ naphthylalkyl, X in formula (VI) is selected from the group consisting of H, M and NR ' ₄ , where M is a metal ion and R' is individually selected from the group consisting of H, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₀ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C _1S naphthylalkyl; and mixtures thereof, and a plurality of particles having a resistivity that is equal to or greater than the resistivity of the non-conductive component when the non-conductive component is electrostatically modified and / or a plurality of particles having a resistivity that is equal to or less than the resistivity of the conductive component when the conductive component is electrostatically modified.

The present invention provides means for improving the electrostatic separation of conductive minerals and non-conductive minerals. A particular advantage of the present invention is to provide improved product quality of zircon and rutile. Another advantage of the present invention is that it increases the production rates of zircon and rutile as opposed to conventional methods. Another advantage of the present invention is that it reduces the loss of zircon or rutile during processing. Another advantage of the present invention is that it reduces the amount of intermediate products and the load of recycling zircon or rutile during processing.

These and other embodiments, objectives and advantages are described in more detail below.

Detailed Description of Preferred Embodiments

Electrostatic separation is a separation method based on differences in the attraction or repulsion of charged particles under the influence of a sufficiently strong electric field. Electrostatic separation is widely used in various industries, including heavy mineral sands. The enrichment of many types of mineral ore, including heavy mineral sands, involves the separation of certain valuable mineral components from other valuable or non-valuable mineral components. Mineral separation plants used in the titanium mineral processing industry operate using similar process technologies that are often constructed locally for individual ore bodies and their separation requirements. Factors that influence the selection of a particular separation methodology include geology, quality of minerals, particle size and shape, type of mineral, inclusions, surface coatings and particles present that affect the method and physical characteristics of the minerals. For example, one ore or mineral sand may contain both rutile and zircon. Both of these minerals have independent uses, and for this reason it is often desirable to separate their relatively pure versions from each other and from other impurities such as ilmenite, monazite, quartz, staurolite and leucoxene.

Electrostatic separation can be used to separate rutile from zircon since rutile is a conductive material and zircon is a non-conductive material. Electrostatic separation can be accomplished by using an electrostatic separator that applies voltages from 21 to 26 kV to the ore, causing conductive components such as rutile and ilmenite to migrate to one edge of the separator, and non-conductive components such as zircon to migrate to the opposite edge separator. Thus, the flow of ground ore or mineral sand is divided into two primary streams using an electrostatic separator to separate conductive components from non-conductive components. The electrostatic separation in accordance with the present invention can be used to separate a variety of mineral systems. These systems include, but are not limited to, mineral sand, ilmenite / staurolite, ilmenite / monazite, rutile / zircon, zircon / leucoxene, iron ore / silicate, granite ilmenite, granite rutile, recycled metal, kyanite / zircon, chromite / garnet and celestine / gypsum.

Various embodiments of the present invention provide reagents for modifying electrostatic properties and methods for using them to improve the enrichment of mineral substrates by improving the efficiency of electrostatic separation. In one embodiment, the electrostatic modification reagent comprises an organic non-polymer compound. In another embodiment, the electrostatic modification reagent comprises an organic polymer or non-polymer compound and a plurality of non-conductive particles. In other embodiments, the electrostatic modification reagent comprises an organic polymer or non-polymer compound and a plurality of conductive particles. In further embodiments, the electrostatic modification reagent comprises at least one organic compound and a plurality of conductive particles and non-conductive particles.

In one embodiment, the electrostatic modification reagent comprises an organic polymer or non-polymer compound selected from the group consisting of quaternary amines; imidazoline compounds; dithiocarbamate compounds; pyridine compounds; conductive polymers such as polypyrroles, polythiophenes and polyanilines; polyethyleneimine; pyrrolidonium; compounds of formula (IV):

(IV) R- (CONH-OX) _n

where n in the formula (IV) is 1-3; wherein R in formula (IV) comprises from 1 to 50 carbon atoms and wherein each X in formula (IV) is individually selected from the group consisting of H, M and NR _'4, wherein M represents a metal ion and R' ₄ are individually selected from the group consisting of H, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₀ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C ₁₈ naphthylalkyl;

compounds of formula (VI):

,

,

where R8 in formula (VI) is selected from H, C ₁ -C ₂₂ alkyl, C ₆ -C ₂₂ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C _1S naphthylalkyl; X in formula (VI) is selected from the group consisting of H, M and NR ′ ₄ , where M is a metal ion and R ′ is individually selected from the group consisting of H, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₀ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C ₁₈ naphthylalkyl; and mixtures thereof.

In one embodiment, the quaternary amine comprises a compound of formula (I),

(I) R (R ₁ R ₂ R ₃ ) N ⁺ X ^- ,

where R in the formula (I) contains from about 1 to about 50 carbon atoms; where R ₁ , R ₂ and R ₃ in the formula (I) are individually selected from the group consisting of H, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₀ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C _1s naphthylalkyl ; and where X is selected from halide, oxide, sulfide, nitride, hydride, peroxide, hydroxide, cyanide, perchlorate, chlorate, chlorite, hypochlorite, nitrate, nitrite, sulfate, sulfite, phosphate, carbonate, acetate, oxalate, tosylate, cyanate, thiocyanate , bicarbonate, permanganate, chromate and dichromate. In one embodiment, the quaternary amine has a numerical molecular weight of about 700 or less, more preferably 450 or less.

As imidazoline compounds, it is meant that unsubstituted as well as substituted imidazolines, quaternized imidazolines and their salts are indicated. In one embodiment, the imidazoline compound comprises a compound selected from compounds of formula (IIa) and their quaternized salts and formula (IIb):

where R ′ ₄ in formula IIa is selected from the group consisting of C ₁ -C ₄ alkyl amines, C ₁ -C ₄ alkoxy and C ₂ -C ₅ alkyl; and where R ₄ in formula IIa is selected from the group consisting of H, C ₁ -C ₂₀ alkyl, C ₂ -C ₂₀ alkenyl, C ₆ -C ₂₀ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C ₁₈ naphthylalkyl; and where R ₁ in formula IIb is selected from the group consisting of H, C ₁ -C ₂₆ alkyl, C ₂ -C ₂₆ alkenyl, C ₆ -C ₂₆ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C ₁₈ naphthylalkyl, oleyl, and where R in formula IIb is selected from the group consisting of H, C ₁ -C ₂₆ alkyl with and without unsaturation, oleyl, C ₂ -C ₂₆ alkenyl, C ₆ -C ₂₆ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C ₁₈ naphthylalkyl.

As pyrrolidine compounds are meant, unsubstituted as well as substituted pyrrolidine, quaternized pyrrolidine, pyrrolidonium and their salts are meant.

As a dithiocarbamate compound, compounds containing a dithiocarbamate group as well as their salts are meant. In one embodiment of the present invention, dithiocarbamate comprises diallylamine dithiocarbamate. In another embodiment, the diallylamine dithiocarbamate is sodium diallylamine dithiocarbamate of formula VII:

In one embodiment, the compound of formula VII has a numerical molecular weight that is about 450 or less.

As a pyridine compound, it is intended to mean unsubstituted as well as substituted pyridines and their salts. In one embodiment of the present invention, pyridine includes a compound of formula (III)

,

,

where R in the formula (III) is selected from the group consisting of H, C ₁ -C ₂₂ alkyl, C ₆ -C ₂₂ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C _1S naphthylalkyl; and where X in formula (III) is selected from a halide, oxide, sulfide, nitride, hydride, peroxide, hydroxide, cyanide, perchlorate, chlorate, chlorite, hypochlorite, nitrate, nitrite, sulfate, sulfite, phosphate, carbonate, acetate, oxalate, tosylate, cyanate, thiocyanate, bicarbonate, permanganate, chromate and dichromate.

In one embodiment of the present invention, the compound of formula IV is selected from monohydroxamic acid, dihydroxamic acids and trihydroxamic acid and any salt thereof. Particularly preferred are C_one-C₁₀ alkyl hydroxamates, more preferably sodium and potassium alkyl hydroxamates. In one embodiment of the present invention, the conductive polymer comprises polyaniline, preferably a modified polyaniline, containing a repeating unit of formula (V):

,

,

where X, Y and Z in the formula (V) are each individually selected from the group consisting of —COOH, —SO ₃ H, and —CO (NH — OH); where R ₇ in the formula (V) is selected from H, C ₁ -C ₂₂ alkyl, C ₆ -C ₂₂ aryl, C ₇ -C ₁₀ aralkyl, C ₁₀ -C ₁₈ naphthylalkyl, sulfate and hydroxyl and where n in the formula (V ) so that polyaniline has a numerical molecular weight in the range of about 500 to about 10,000.

In one embodiment, the polyethyleneimine has a molecular weight in the range of about 350 to about 1000, and preferably contains a repeating unit of formula (VIII)

,

,

where n in the formula (VIII) is chosen so that the polyethyleneimine has a molecular weight in the range of from about 350 to about 1000; and mixtures thereof.

In one embodiment of the present invention, the reagent for modifying the electrostatic properties further comprises a plurality of particles having an average resistivity that is equal to or greater than the resistivity of the non-conductive component when the non-conductive component is that component in the mixture that is to be electrostatically modified, and / or a plurality of particles having an average resistivity that is equal to or less than the resistivity of the conductive component, to where the conductive component is that component in the mixture that must be electrostatically modified. Particles in a reagent for modifying electrostatic properties preferably have an average diameter of from 1 to 500 microns.

The mass ratio of the modifier of electrostatic properties to particles is preferably from about 100: 1 to about 1: 100.

Thus, the efficiency of electrostatic separation can be improved by incorporating a plurality of particles having an average resistivity that is equal to or greater than the resistivity of a non-conductive component, hereinafter referred to as "non-conductive particles", in the reagent for modifying the electrostatic properties. In various embodiments, the electrostatic modification reagent comprises a plurality of non-conductive particles and an organic compound selected from the group consisting of those organic compounds described above. The electrostatic modification reagent preferably comprises a plurality of non-conductive particles and at least one organic compound selected from the group consisting of quaternary amines; imidazoline compounds; dithiocarbamate compounds; pyridine compounds; pyrrolidine compounds; conductive polymers; polyethyleneimines and mixtures thereof, more preferably at least one compound selected from the group consisting of quaternary amines, imidazoline compounds, in particular quaternized imidazoline compounds and pyridine compounds. Particularly preferred are the compounds of formula (I), (IIa), (IIb) and (III).

Many non-conductive particles and an organic compound may be present in the reagent to modify electrostatic properties in a mass ratio of non-conductive particles: organic compound in the range of about 100: 1 to 1: 100.

In one embodiment, the non-conductive particles are selected from a silicate of the formula (M _x O _y ) _p (SiO ₂ ) _q , an aluminate of the formula M _x AlO _z, and mixtures thereof, where M is a metal (e.g., Al, Sn, Zr or Pb ); x and y, each individually are in the range of from about 1 to about 4; z ranges from about 1 to about 12, and the p: q ratio ranges from about 10: 1 to about 1:10. Other non-conductive particles that have a size distribution, conductivity and morphology similar to silicate and aluminate particles may be included in the reagent to modify electrostatic properties instead of and / or in addition to such silicates and aluminates. In another embodiment, the non-conductive particles are selected from polystyrene, quartz, mica, talc, sulfur, ebonite, shellac, lucite, powder glass, dry wood, celluloid, ivory, and mixtures thereof. Additional examples of suitable non-conductive particles include those that contain a mineral selected from the group consisting of kaolin and montmorillonite. In another example, many non-conductive particles may contain aluminosilicate clay. Non-conductive particles that have a chemical structure and / or composition that is similar to the non-conductive component present in the mineral substrate are preferred. When the mineral substrate contains zircon, the non-conductive particles are preferably selected from zircon, sand and silica. Non-conductive particles in a reagent for modifying electrostatic properties may be obtained from commercial sources and / or may be manufactured using techniques known to those skilled in the art. More preferably, non-conductive particles, in particular particles of silicon oxide and zircon, are of high purity with an iron content below 1.0%.

Many non-conductive particles in the electrostatic modification reagent may have an average diameter of less than about 500 microns, for example, less than about 300 microns or less than about 200 microns. Non-conductive particles preferably have an average diameter of at least 1 micron, more preferably at least 10 microns. Particularly preferred are non-conductive particles having a diameter of about 50-200 microns. In one embodiment, non-conductive particles have an aspect ratio ranging from about 1 to about 100.

Improved separation is often observed when the particle size for non-conductive particles in the electrostatic modification reagent decreases. For example, in certain applications, it may be desirable to use non-conductive microparticles with the smallest possible particle size. Often good results can be obtained using non-conductive particles having an average diameter of less than about 200 microns, for example, less than about 100 microns. Many non-conductive particles in a reagent for modifying electrostatic properties may have a single-mode or multi-mode (eg, two-mode) particle size distribution.

In any given situation, the size of the non-conductive particles can be selected based on various practical considerations, such as cost, productivity, mineral substrate to be processed, desirability of eliminating selected impurities and / or desired level of separation. So, for example, in some applications, a relatively low level of separation can be obtained using an electrostatic reagent that contains non-conductive silicate microparticles having an average particle size in the range of about 1 to about 500 microns. In other situations, for example, when a high level of separation is desired, smaller non-conductive microparticles are often preferred. The sizes of the non-conductive particles can be determined by measuring their surface areas using the N2 BET adsorption method (see US Patent Publication No. 2007/0007179). Specialists in this field understand the relationship between particle size and surface area, as determined using the N2 BET adsorption method.

In another embodiment, the efficiency of electrostatic separation is improved by incorporating into the reagent for modifying the electrostatic properties of a plurality of particles having an average resistivity that is equal to or less than the resistivity of the conductive component, hereinafter referred to as “conductive particles”. Although the present invention is not limited to its theory of operation, it is contemplated that an organic compound in a reagent for modifying electrostatic properties selectively combines conductive particles with conductive minerals. In various embodiments, the electrostatic modification reagent comprises a plurality of conductive particles and an organic polymer or non-polymer compound, preferably selected from those described above.

The electrostatic modification reagent preferably contains a plurality of conductive particles and at least one organic compound selected from the group consisting of compounds of formulas (IV), (V), (VI), (VII) and (VIII), more preferably compound of formula (IV).

A plurality of conductive particles and an organic compound may be present in the reagent to modify electrostatic properties in a mass ratio of conductive particles: organic compound in the range of about 100: 1 to 1: 100, for example, in the range of about 10: 1 to about 1:10.

In other embodiments, the conductive particles can comprise a metal oxide of formula M _x O _y, wherein M represents a transition metal, and where x and y, each, individually, are in the range from about 1 to about 6. The transition metal may be selected from Cu , Co, Mn, Ti, Fe, Zn, Mo, and Ni. In some embodiments, the conductive particles may comprise metal oxide, which is a superconducting material of the formula A _p B _q D _r O _s , where A is La, Pr, Ce, Nd, Sm, Eu, Gd, Ho, Er, Tm Yb, Lu or Nb; B represents Ca, Ba, or Sr; D represents Cu, Ni, Ti or Mo, O represents oxygen, p ranges from about 0.01 to about 2.0; q ranges from about 0.5 to about 3; r is in the range of about 0.1 to about 5 and s is in the range of about 1 to about 10. Those skilled in the art will understand that in this context, the term “superconducting material” refers to a material that is superconducting at temperatures above 4 K, regardless of the temperature of the reagent for modifying the electrostatic properties, at any given time. Other conductive particles that have a size distribution, conductivity and morphology similar to metal oxide particles can be included in the reagent to modify electrostatic properties instead of and in addition to such metal oxides.

The plurality of conductive particles may also include any metal particles, such as, for example, silver, copper, gold, aluminum, iron, and mixtures thereof. Other conductive particles may include graphite, covellite, pentlandite, magnetic pyrite, galena (lead sulfide), silicon, arsenopyrite, magnetite, chalcosine, chalcopyrite, plate pyrite, molybdenite, and mixtures thereof. Preferred are conductive particles that have a chemical structure and / or composition that is similar to the conductive component present in the mineral substrate. When the mineral substrate contains rutile, non-conductive particles are preferably selected from rutile. More preferably, the conductive particles, in particular rutile, have a high purity with a content of non-conductive particles such as silica and zircon present below 1.0%.

Many conductive particles may have an average diameter of less than about 100 microns, for example, less than about 50 microns. The conductive particles preferably have an average diameter of at least 1 micron, more preferably at least 10 microns. Particularly preferred are conductive particles having a diameter of about 10-100 microns. The size of the conductive particles can be determined by measuring their surface area using the adsorption method N2 BET (see publication of US patent No. 2007/0007179). Specialists in this field understand the relationship between particle size and surface area, as determined using the N2 BET adsorption method. Conducting particles in a reagent for modifying electrostatic properties can be obtained from commercial sources and / or obtained using technologies known to specialists in this field.

The electrostatic modification reagent may optionally contain additional ingredients. For example, in one embodiment, the electrostatic modification reagent comprises a liquid, such as alcohol and / or water. In another embodiment, the electrostatic modification reagent comprises a dispersant. In another embodiment, the electrostatic modification reagent comprises a liquid, such as alcohol and / or water, and a dispersant. Amounts of a reagent for modifying electrostatic properties, an optional liquid, and an optional dispersant can vary over a wide range, which can be determined using routine experiments, guided by the description given in this document. For example, in one embodiment, the reagent for modifying the electrostatic properties, the amount of liquid (e.g., water, oil (e.g., mineral oil, synthetic oil, vegetable oil) and / or alcohol) ranges from zero to about 95%, and the amount of dispersant is in the range from zero to about 10%, all previous amounts are percent by weight relative to the total weight of the reagent to modify the electrostatic properties.

Additional inclusion of an optional dispersant in the reagent to modify electrostatic properties can provide a variety of beneficial effects. For example, the inclusion of a dispersant may facilitate dispersion of the reagent to modify the electrostatic properties that the liquid contains, and / or the dispersant may facilitate dispersion of the mineral particles and / or impurities of the mineral substrate with which the reagent is mixed to modify the electrostatic properties. The dispersant may be an organic dispersant, such as a water-soluble polymer, or a mixture of such polymers, an inorganic dispersant, such as silicate, phosphate or a mixture thereof, or a mixture of organic and inorganic dispersants. An example of a suitable organic dispersant is a water-soluble or water-dispersible polymer that contains at least one residue selected from the group consisting of carboxyl and sulfonate. Polyacrylic acid and Na-polyacrylate are examples of water-soluble or water-dispersible polymers that contain a carboxyl group. Poly (2-acrylamido-2-methyl-1-propanesulfonate), also known as poly (AAMPS), is an example of a water-soluble or water-dispersible polymer that contains a sulfonate group. Other suitable organic dispersants include natural and synthetic resins and rubbers such as guar gum, hydroxyethyl cellulose and carboxymethyl cellulose. The amount of dispersant is preferably in the range from zero to about 15 pounds (6 kg) of dispersant per ton of reagent to modify the electrostatic properties.

In another embodiment, the electrostatic modification reagent is provided in liquid form, for example, in the form of a dispersion. For economy, the liquid is preferably water, although the liquid form may contain other liquids, such as oil and / or alcohol, in addition to or instead of water.

The liquid is preferably present in an amount that makes the liquid form fluid, for example from about 25% to about 95% of the liquid by weight, relative to the total weight of the dispersion, more preferably from about 35% to about 75%, with the same ratio. Optionally, a dispersant can be used to obtain a uniform and stable dispersion of the components in the liquid. Examples of preferred dispersants include the inorganic and organic dispersants described above. The amount of dispersant in the dispersion is preferably the amount that is effective in obtaining a stable dispersion of insoluble ingredients, for example from about 0.1% to about 10%, more preferably from about 1% to about 5% by weight relative to the total weight of the dispersion.

The reagent for modifying the electrostatic properties can be obtained in various ways. For example, in one embodiment, the electrostatic modification agent is in the form of a substantially dry mixture, optionally containing an additional dispersant. Such a substantially dry mixture may be formed, for example, by mixing the components, or by suspending, dispersing, diluting or dissolving the components in a liquid, optionally by heating and / or stirring, and then removing the liquid to form a substantially dry mixture. In another embodiment, the electrostatic modification agent is in the form of a fluid mixture containing a liquid (e.g., water and / or alcohol) and optionally containing an additional dispersant. As indicated above, the reagent for modifying the electrostatic properties in such a fluid mixture can be suspended (for example, in the form of a colloidal suspension), dispersed (for example, in the form of a dispersion) and / or liquefied in a liquid, and / or one or more compounds containing heteroatoms can be suspended disperse, liquefy and / or dissolve in a liquid. Such a fluid mixture can be formed by mixing the components (in any order), preferably with stirring, optionally with heating. Various preparations can be prepared using routine experiments, knowing the information provided in this document.

Another embodiment provides a method of enriching a mineral substrate by electrostatically separating a dry mixture, comprising mixing the mineral substrate and the reagent to modify the electrostatic properties to form a mixture containing an electrostatically modified component, and applying an electric field to the mixture, so that at least partially separate the electrostatically modified component from the mixture. The electrostatic modifier present in the modification reagent is selectively associated with one or more components of the mineral substrate (e.g., a conductive mineral (s) or non-conductive mineral (s)) to form an electrostatically modified component. When an electric field is applied, the separation of the electrostatically modified component from the rest of the mixture improves with respect to separation under essentially identical conditions in the absence of a reagent for modifying the electrostatic properties. The electrostatic modification reagent used in the enrichment method is preferably an electrostatic modification reagent, as described elsewhere herein.

The mineral substrate is typically provided in the form of particles, for example, as ground or ground powder. The average particle size of the particulate mineral substrate is usually less than about 1 mm. In one embodiment, the average particle size of the mineral substrate is less than about 500 microns, for example, less than about 100 microns. In one embodiment, the average particle size of the mineral substrate is greater than about 10 microns, for example, greater than about 30 microns. For example, in one embodiment, the average particle size of the mineral substrate is in the range of about 30 microns to about 100 microns.

The mineral substrate and the reagent for modifying the electrostatic properties can be mixed in various ways, for example, at one stage, at many stages, sequentially, in reverse order, simultaneously or in various combinations of these methods. For example, in one embodiment, various components, for example, a reagent for modifying electrostatic properties, optional ingredients such as water, a dispersant, and the like, are added to a portion of the mineral substrate to form a premix, then it is mixed with the mineral substrate. In another embodiment, the reagent for modifying the electrostatic properties is formed in situ by separately and sequentially mixing the components of the reagent to modify the electrostatic properties with the mineral substrate. Alternatively, a reagent for modifying electrostatic properties may be added simultaneously (without first forming a premix) to the mineral substrate. Various add modes are effective.

The amount of reagent for modifying the electrostatic properties mixed with the mineral substrate is preferably an amount that is effective for improving the separation of the components of the mineral substrate, for example, in order to separate a valuable mineral from an invaluable mineral, a non-conductive mineral from a conductive mineral by applying an electric field. In many cases, it is preferable to determine the amount of reagent for modifying the electrostatic properties, which should be mixed with the mineral substrate, based on the quantities of the individual components in the reagent for modifying the electrostatic properties. In one embodiment, the reagent for modifying the electrostatic properties is mixed with a mineral substrate with a ratio in the range of about 0.01 kg of reagent for modifying the electrostatic properties per ton of the mineral substrate to about 5 kg of reagent for modifying the electrostatic properties per ton of the mineral substrate. In one embodiment, the reagent for modifying the electrostatic properties is mixed with a mineral substrate at a ratio of from about 0.01 kg of an electrostatic modifier, such as an organic compound, per ton of mineral substrate to about 5 kg of an electrostatic modifier, such as an organic compound, ton of mineral substrate. In one embodiment, the plurality of conductive or non-conductive particles are mixed with the mineral substrate at a ratio of from about 0.01 kg of the plurality of particles per ton of the mineral substrate to about 5 kg of particles per ton of the mineral substrate.

At any time prior to the application of an electric field, the pH of the mineral substrate can be adjusted, for example, preferably adjusted to a pH in the range of about 6 to about 11, most preferably to a pH in the range of about 7 to about 9. Any alkali can be used to increase the pH. like sodium hydroxide, or a mixture of sodium silicate and sodium hydroxide. Alternatively, the pH may be adjusted using sodium silicate or soda ash.

The enrichment or separation of the mixture into mineral components, including the electrostatically modified component obtained by mixing the mineral substrate and the reagent to modify the electrostatic properties, can be carried out by applying an electric field to the mixture in order to separate the valuable mineral (s) from the non-valuable mineral (s). In one embodiment, the mixture is conditioned and dried until an electric field is applied. Suitable conditioning times for a particular application can be determined using routine experimentation using the information provided in this document. After conditioning, the mixture containing the electrostatically modified component is typically dried to form a dry mixture having a water content of about 5% or less, for example about 2% or less, by weight relative to the total weight. Suitable drying methods known to those skilled in the art may be used.

The conditioned and dried mixture containing the electrostatically modified component may then undergo electrostatic separation. Electrostatic separation is preferably carried out at a point in time that is in the range of about time directly after conditioning to about 4 days after conditioning, for example, in the range of about 3 days, two days or one day after conditioning. Equipment suitable for performing electrostatic separation is commercially available and known to those skilled in the art.

The reagent for modifying the electrostatic properties is preferably selected to achieve a certain level of separation between the conductive mineral and the non-conductive mineral, which is greater than the level of separation obtained in the absence of a reagent for modifying the electrostatic properties. More preferably, the separation level is at least about 5% more, even more preferably at least about 10% more, even more preferably at least about 15% more than a comparable separation level, achieved in the absence of a reagent for modifying electrostatic properties.

After electrostatic separation, the resulting enriched product may be subjected to additional processing steps to obtain the separated valuable mineral (s) and non-valuable mineral (s) in the desired form. Thus, any desired processing steps, such as, for example, magnetic separation, can be carried out on the resulting enriched product, which contains an electrostatically modified component that is at least partially separated from the mixture.

In addition, the present invention relates to a reagent for modifying electrostatic properties, containing at least one modifier of electrostatic properties and a plurality of conductive and / or non-conductive particles with a mass ratio of the modifier of electrostatic properties to particles from about 100: 1 to about 1: 100. In one embodiment, the electrostatic modifier may be a mixture of any and all quaternary amines and / or imidazoline and pyrrolidonium compounds with a molecular weight ranging from 450 to 700, and the plurality of microparticles is any combination of silicon oxide or metal silicates, or zirconium silicate with a size of less than 500 micrometers and aspect ratio ranging from 1 to 50 at any mass ratio.

In one embodiment, the electrostatic modification reagent is added to a heavy mineral concentrate (HMC). In one embodiment, the reagent is added to a heavy mineral concentrate with a size below 700 micrometers (0.7 mm esd (statistical instrument data)). Some embodiments of the method for obtaining improved separation efficiency for the separation of rutile-zircon using the method and materials for electrostatic separation of the present invention include, but are not limited to, the following (in general, the order of addition of the reagent can be reversed, the drying step can be carried out in a furnace or other heating device at temperatures ranging from about 100 ° to about 180 °, electrostatic separation can take place at any temperature, For example, ranging from room temperature to about 140 ° C, including but not limited to temperatures reaching 50 ° C or lower, and the applied voltage in the electrostatic separator may be from about 21 to about 27 kV, the rotation speed is from about 230 up to about 300 revolutions per minute and the feed rate is from about 35 to about 65 kg · hour / inch (88-163 kg · hour / cm)). Some examples of a process for obtaining improved separation efficiency for the separation of rutile zircon include the following:

1) Preparation of starting materials with 25-75% solids in water - addition of non-conductive silicate microparticles - then addition of an organic compound of the formula (I, IIa, IIb, III or IV) - scrubbing scrubbing - filtering - drying at 140 ° C - electrostatic separation - separation of non-conductive and conductive parts - additional processing;

2) Preparation of starting materials with 25-75% solids in water - addition of a compound of formula (I or others) - scrubbing scrubbing - filtering - drying at 140 ° C - electrostatic separation - separation of non-conductive and conductive parts - additional processing;

3) Preparation of starting materials with 25-75% solids in water - addition of a compound of formula (I or others) - filtration - drying at 140 ° C - electrostatic separation - separation of non-conductive and conductive parts - additional processing;

4) Preparation of starting materials with 25-75% solids in water - addition of non-conductive silicate microparticles - then addition of a compound of formula (I or II or III or IV) - filtration - drying at 140 ° C - electrostatic separation - separation of non-conductive and conductive parts - additional processing;

5) Preparation of starting materials with 25-75% solids in water - adding a compound of formula (I or others) in a sump pump - filtering - drying at 140 ° C - electrostatic separation - separation of non-conductive and conductive parts - additional processing;

6) Preparation of starting materials with 25-75% solids in water - addition of non-conductive silicate microparticles - then compounds of formula (I or II or III or IV) in a sump pump - filtration - drying at 140 ° C - electrostatic separation - separation of non-conductive and conductive parts - additional processing;

7) Mixing the starting materials with 30-75% solid products in water - adding a compound of formula (I or friend) in a sump pump - centrifugation - drying at 140 ° C - electrostatic separation - separation of non-conductive and conductive parts - additional processing;

8) Mixing the starting materials with 30-75% solids in water - adding non-conductive silicate microparticles - then the compounds of formula (I or II or III or IV) in a sump pump - centrifugation - drying at 140 ° C - electrostatic separation - non-conductive separation and conductive parts - additional processing;

9) Mixing the starting materials with 30-75% solids in water - adding a compound of formula (I or others) in a sump pump - static mixer - filtering - drying at 140 ° C - electrostatic separation - separation of non-conductive and conductive parts - additional processing ;

10) Mixing the starting materials with 30-75% solids in water - adding non-conductive silicate microparticles - then the compounds of formula (I or II or III or IV) in the sump pump - static mixer - filtering - drying at 140 ° C - electrostatic separation - separation of non-conductive and conductive parts - additional processing;

11) Adding a compound of formula (I or others) to the starting materials in a wet high gradient magnetic separator or before it in the process stream - filtering - drying at 140 ° C - electrostatic separation - separation of non-conductive and conductive parts - additional processing;

12) Preparation of starting materials with 30-75% solids in water - addition of non-conductive or insulating silicate microparticles - then compounds of formula (I or II or III) in a sump pump - static mixer - filtering - drying at 140 ° C - electrostatic separation - separation of non-conductive and conductive parts - re-preparation of starting materials with intermediate products, with 30-75% solids in water - addition of non-conductive or insulating silicate microparticles - then compounds of formula (I or II or III) - filtering - drying at 140 ° C or higher - electrostatic separation - separation of non-conductive and conductive parts - additional processing.

The method of the present invention provides means for improving the efficiency of electrostatic separation of conductive minerals and non-conductive minerals. Another embodiment of the present invention is to apply the method to mixtures of minerals, such as mineral sand; mixtures of ilmenite / staurolite; ilmenite / monazite; rutile / zircon; zircon / leucoxene; rock ilmenite / rutile; kyanite / zircon; chromite / garnet; celestin / gypsum; as well as recycled metals and silicate removed from iron ore.

When applied to the processing of minerals containing rutile and zircon, the method of the present invention provides an improved product quality of zircon and rutile, as well as an increase in the rate of their production, compared to conventional methods. Another advantage of the present invention is that it reduces the loss of zircon and / or rutile during processing. Another advantage is that it reduces the amount of intermediate products and the load of recycling zircon and / or rutile during processing.

In the above embodiments of the process, the additional processing may include one or more of the following processes: no processing and electrostatic separation or treatment with a reagent, drying and additional separation using electrostatic separation.

Examples 1-8

The volumetric amount of the primary raw materials of the rutile / zircon mineral substrate (25-30 kg) passes through a groove divider to obtain a series of loads of samples of the mineral substrate, each of which contains approximately 500 g of the mineral substrate. The mineral substrate contains about 22% TiO ₂ and about 59-60% ZrSiO ₄ . Each of 500 g sample downloads is packaged and stored separately. For each example, a suspension is prepared by mixing about 500 g of dry starting materials and about 166.0 g of water to obtain a suspension with 75% solids. The amounts of electrostatic modification reagent shown in Table 1 are 0.25 g or 0.5 g (0.5 or 1.0 kg / t), mixed with a portion of the suspension and conditioned by high speed stirring for about one minute premix formation. The remaining suspension is then added to this mixture and conditioned at natural pH for 2, 5, or 10 minutes to form a conditioned suspension. The conditioned suspension is transferred to a tray and the solution is decanted. The tray is placed in an oven at 140 ° C for approximately 3 hours to obtain a dry mixture containing an electrostatically modified component. The dry mixture is sieved through a sieve device (size 14) to destroy any agglomerates. A tray containing the sifted dry mixture is placed in an oven to be brought back to a predetermined temperature. Then the pan is quickly removed from the oven, and the sieved dry mixture passes through an electrostatic separator (model HTP (25) 111-15 from Outotec, Jacksonville, FL) at a speed of 260 rpm, an applied voltage of 23 kV, and a feed rate of 50 kg hour / inch (125 kg · hour / cm). A plant with 18 pallets is used to collect the product. Pallets 1-9 (C) are designated as the conductive part, 10-12 as part 1 of the intermediate products (M1), 13-15 as part 2 of the intermediate products (M2), 16-17 as part 3 of the intermediate products (M3) and 18 ( NC) as a non-conductive part. Masses are recorded in the above pallets. Then carry out the analysis of XRF (X-ray luminescence) for each group (conductive part, intermediate products 1,2,3 and non-conductive part). Mass recovery (mass of each part) and quality (XRF analysis) are plotted and performance curves are determined.

Efficiency values are first determined for individual pallets. They are estimated using the following calculations. For example, for M1:

Rutile extraction (M1), R _Ti (M1) = G _Ti (M1) × Wt (M1) / G _Ti (starting materials) × Total weight of starting materials

Zircon recovery (M1), R _Zr (M1) = G _Zr (M1) × Wt (M1) / G _Zr (starting materials) × Total weight of starting materials

Cumulative extraction of rutile (M1), CR _Ti (M1) = R _Ti (C) + R _Ti (M1)

Cumulative extraction of zircon (M1), CR _Zr (M1) = R _Zr (C) + R _Zr (M1)

Cumulative efficiency (M1), CE (M1) = [CR _Ti (M1) + (100-CR _Zr (M1)] / 2

Maximum efficiency (ME) represents the highest value among cumulative efficiency values CE (C) ... CE (M2) ... CE (NC).

As already considered, if the reagent improves separation, then the maximum separation efficiency (ME) with the reagent will be higher than the control (without reagent), and the difference (ΔE) from 3 to 5% is significant in laboratory work.

Table 1
Efficiency Improvement (ΔE) with Specific Surfactants No. of Example Reagent for electrostatic modification ΔE = ME _Test -ME _control one Alkylimidazoline 2.0 2 Alkylimidazoline marketed as Miramine TO-DT 1.9 3 Quaternary amine marketed as Aero 3100G 1,0 four Trialkylphosphine Oxide Marketed as Cyanex 923 0.9 5 Sodium diallylamine dithiocabamate 2,4 6 Nonylsulfonate marketed as Witconic 1298 soft 4.4 7 Quaternary amine marketed as Tego Betaine 810 1,1

Examples 8-12

A bulk amount of starting materials (25-30 kg) passes through a grooved divider to obtain a good representative sample of starting materials. Using a continuous separation procedure, the sample size is reduced to approximately 500 g. Each of 500 g of representative sample loads is packaged and stored separately. Each study contains 500 g of dry starting materials, and approximately 166.0 g of water is added to them to obtain a suspension with 75% solids. The suspension is then transferred to an octagonal tall tubular steel container. Then it is placed under the "Delta" drilling machine. A reagent, 0.5 kg / t, was added to it and homogenized for 1 minute. Then, starting materials are added to this mixture and conditioned at natural pH for 10 minutes. The resulting suspension was transferred to a tray and the solution was decanted. The tray is placed in an oven at 140 ° C for approximately 3 hours, and the processed starting materials are sieved through a sieve device (size 14) to break any agglomerates. A tray with a sifted sample is placed in an oven to be brought back to a predetermined temperature. Then the pan is quickly removed from the furnace, and the sample passes through an electrostatic separator (model HTP (25) 111-15) at a speed of 260 rpm, an applied voltage of 23 kV and a feed rate of 50 kg · h / in (125 kg · h / cm). A plant with 18 pallets is used to collect the product. Pallets 1-9 (C) are designated as the conductive part, 10-12 as part 1 of the intermediate products (M1), 13-15 as part 2 of the intermediate products (M2), 16-17 as part 3 of the intermediate products (M3) and 18 ( NC) as a non-conductive part. Masses are recorded in the above pallets. Then carry out XRF analysis for each group (conductive, intermediate products - 1, 2, 3 and non-conductive part). The extracted mass (mass of each part) and quality (XRF analysis) are plotted to evaluate performance curves.

Maximum efficiency (ME) represents the highest value among cumulative efficiency values CE (C) ... CE (M2) ... CE (NC).

As stated above, if the reagent improves separation, then the maximum separation efficiency (ME) with the reagent will be higher than the control (without reagent), and the difference (ΔE) from 3 to 5% is significant in laboratory work.

table 2
Performance Improvement (AE) with Conductive Polymers Examples Reagent ΔE = ME _test -ME _control 8 Polypyrrole-SO3H 1.4 9 Polyaniline-3COOH 2,3 10 Polyaniline (ES) applied to lignin * 1.7 eleven Polyethyleneimine 2.6 12 Low molecular weight makec acid styrene sulfonate copolymer marketed as Cyanamer P80 2.0

Examples 13-16

A bulk amount of starting materials (25-30 kg) passes through a grooved divider to obtain a good representative sample of starting materials. Using a continuous separation procedure, the sample size is reduced to approximately 500 g. Each of 500 g of representative sample loads is packaged and stored separately. Each study contains 500 g of dry starting materials, and approximately 166.0 g of water is added to them to obtain a suspension with 75% solids. The suspension is then transferred to an octagonal tall tubular steel container. Then it is placed under the "Delta" drilling machine. Reagent, 0.5 kg / t Miramine OT-DT and 0.5 kg / t microparticles are added to it and homogenized for 1 minute. Then, starting materials are added to this mixture and conditioned at a natural pH for 10 minutes. The resulting suspension was transferred to a tray and the solution was decanted. The tray is placed in an oven at 140 ° C for approximately 3 hours, and the processed starting materials are sieved through a sieve device (size 14) to break any agglomerates. A tray with a sifted sample is placed in an oven to be brought back to a predetermined temperature. Then the pan is quickly removed from the furnace, and the sample passes through an electrostatic separator (model HTP (25) 111-15) at a speed of 260 rpm, an applied voltage of 23 kV and a feed rate of 50 kg · h / inch. A plant with 18 pallets is used to collect the product. Pallets 1-9 (C) are designated as the conductive part, 10-12 as part 1 of the intermediate products (M1), 13-15 as part 2 of the intermediate products (M2), 16-17 as part 3 of the intermediate products (M3) and 18 ( NC) as a non-conductive part. Masses are recorded in the above pallets. Then carry out XRF analysis for each group (conductive part, intermediate products - 1, 2, 3 and non-conductive part). The extracted mass (mass of each part) and quality (XRF analysis) are plotted to evaluate performance curves.

Maximum efficiency (ME) represents the highest value among cumulative efficiency values CE (C) ... CE (M2) ... CE (NC).

As discussed above, if the reagent improves separation, then the maximum separation efficiency (ME) with the reagent will be higher than the control (without reagent), and a difference (ΔE) of 3 to 5% is significant in laboratory work.

Table 3
Improving Efficiency (ΔE) by Selectively Adding Insulating Particles Examples Reagent ΔE = ME _Test -ME _control 13 Miramine TO-DT (imidazoline) + silicon nanooxide (10 nm) 1,2 fourteen Miramine TO-DT (imidazoline) + colloidal silicon oxide 6.0 fifteen Miramine TO-DT (imidazoline) + ground zircon 6.8 16 Miramine TO-DT (imidazoline) + sand 5.3 17 Valine-O (alkylimidazoline) + zircon 9.8 eighteen CP 5596-93 (quaternized alkylimidazoline) + sand 8.8 19 Valine-O (alkylimidazoline) + sand 11.1

Examples 17-20

A bulk amount of starting materials (25-30 kg) passes through a grooved divider to obtain a good representative sample of starting materials. Using a continuous separation procedure, the sample size is reduced to approximately 500 g. Each of 500 g of representative sample loads is packaged and stored separately. Each study contains 500 g of dry starting materials, and approximately 166.0 g of water is added to them to obtain a suspension with 75% solids. The suspension is then transferred to an octagonal tall tubular steel container. Then it is placed under the "Delta" drilling machine. A reagent, 0.5 kg / t of alkyl hydroxamate (S9849, Cytec Industries) (Formula IV) and microparticles are added to it and homogenized for 1 minute. Then, starting materials are added to this mixture and conditioned at a natural pH value for 2, 5 or 10 minutes. The resulting suspension was transferred to a tray and the solution was decanted. The tray is placed in a 140 ° C oven for about 3 hours, and the processed starting materials are sieved through a sieve device (size 14) to break any agglomerates. A tray with a sifted sample is placed in an oven to be brought back to a predetermined temperature. Then the pan is quickly removed from the furnace, and the sample passes through an electrostatic separator (model HTP (25) 111-15) at a speed of 260 rpm, an applied voltage of 23 kV and a feed rate of 50 kg · h / inch. A plant with 18 pallets is used to collect the product. Pallets 1-9 (C) are designated as the conductive part, 10-12 as part 1 of the intermediate products (M1), 13-15 as part 2 of the intermediate products (M2), 16-17, as part 3 of the intermediate products (M3) and 18 (NC) as a non-conductive part. Masses are recorded in the above pallets. Then carry out XRF analysis for each group (conductive part, intermediate products - 1, 2, 3 and non-conductive part). The extracted mass (mass of each part) and quality (XRF analysis) are plotted to evaluate performance curves.

Maximum efficiency (ME) represents the highest value among cumulative efficiency values CE (C) ... CE (M2) ... CE (NC).

As stated above, if the reagent improves separation, then the maximum separation efficiency (ME) with the reagent will be higher than the control (without reagent), the difference (ΔE) from 3 to 5% is significant in laboratory work.

Table 4
Efficiency Improvement (ΔE) by Selectively Attaching Conductive Particles Examples Reagent ΔE = ME _Test -ME _control 17 Alkyl hydroxamate marketed as S9849 + TiO2 nano-needles 0.2 eighteen S9849 + TiO2 nanoparticles (5 nm) 1,6 19 S9849 + TiO2 powder 0.6 twenty S9849 + chopped rutile 5,4

Claims (30)

1. A method of enriching a mineral substrate by electrostatic separation, wherein said mineral substrate contains a conductive mineral component and / or a non-conductive mineral component, the method comprising the steps of:
mixing the mineral substrate and the reagent to modify the electrostatic properties in the liquid to form a suspension, where at least one of said conductive mineral component and / or said non-conductive mineral component is electrostatically modified;
drying said suspension to give a substantially dry mixture; and
applying an electric field to the dry mixture and separating at least a portion of the electrostatically modified mineral component from the dry mixture;
where the reagent for modifying the electrostatic properties comprises an electrostatic modifier selected from an organic compound selected from the group consisting of quaternary amines; imidazoline compounds; dithiocarbamate compounds; pyridine compounds; pyrrolidine compounds; conductive polymers selected from polypyrroles, polythiophenes and polyanilines; polyethyleneimines; compounds of formula (IV):
(IV) R- (CONH-O-X) _n
where n in the formula (IV) is 1-3; where R contains from 1 to 50 carbon atoms and where each X in the formula (IV) is individually selected from a representative of the group consisting of H, M and NR ′ ₄ , where M is a metal ion and each of R ′ is individually selected from a representative of the group consisting of H, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₀ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C ₁₈ naphthylalkyl;
compounds of formula (VI):

where R8 is selected from a representative of the group consisting of H, C ₁ -C ₂₂ alkyl, C ₆ -C ₂₂ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C ₁₈ naphthylalkyl, and X in formula (VI) is selected from a representative of the group consisting of H, M and NR ′ ₄ , where M represents a metal ion and each R ′ is individually selected from a representative of the group consisting of H, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₀ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C ₁₈ naphthylalkyl; and
their mixtures. 2. A method of enriching a mineral substrate using electrostatic separation, wherein said mineral substrate contains a conductive mineral component and / or a non-conductive mineral component, the method comprising the steps of:
mixing the mineral substrate and the reagent to modify the electrostatic properties in the liquid to form a suspension, where at least one of said conductive mineral component and / or said non-conductive mineral component is electrostatically modified;
drying said suspension to give a substantially dry mixture; and
applying an electric field to the dry mixture and separating at least a portion of the electrostatically modified mineral component from the dry mixture;
where the reagent for modifying the electrostatic properties comprises at least one electrostatic modifier and a plurality of particles having an average resistivity that is equal to or greater than the resistivity of the non-conductive mineral component when the non-conductive mineral component is electrostatically modified, and / or a plurality of particles having an average resistivity that is equal to or less than the resistivity of the conductive mineral component when conductive the mineral component is electrostatically modified. 3. The method of claim 2, wherein the electrostatic modifier comprises an organic compound selected from a representative selected from the group consisting of quaternary amines; imidazoline compounds; dithiocarbamate compounds; pyridine compounds; pyrrolidine compounds; conductive polymers; polyethyleneimines; compounds of formula (IV):
(IV) R- (CONH-OX) _n
where n in the formula (IV) is 1-3; where R contains from 1 to 50 carbon atoms and where each X in the formula (IV) is individually selected from the group consisting of H, M and NR ′ ₄ , where M is a metal ion and each R ′ is individually selected from
a representative selected from the group consisting of H, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₀ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C ₁₈ naphthylalkyl; compounds of formula (VI):

where R8 is selected from a representative selected from the group consisting of H, C ₁ -C ₂₂ alkyl, C ₆ -C ₂₂ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C ₁₈ naphthylalkyl, and X is selected in formula (VI) from a representative selected from the group consisting of H, M and NR ′ ₄ , where M is a metal ion and each R ′ is individually selected from a representative selected from the group consisting of H, C ₁ -C ₁₀ alkyl, C ₆ - C ₁₀ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C ₁₈ naphthylalkyl; and
their mixtures. 4. The method of claim 1 or 3, wherein the electrostatic modifier comprises a quaternary amine compound of the formula I:
(I) R (R ₁ R ₂ R ₃ ) N ⁺ X ^- ,
where R in the formula (I) contains from 1 to 50 carbon atoms;
where each of R ₁ , R ₂ and R _{3 is} individually selected from a representative selected from the group consisting of H, C ₁ -C ₁₀ alkyl, C ₆ -C ₁₀ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C ₁₈ naphthylalkyl and
where X in the formula (I) is selected from a representative selected from the group consisting of halide, oxide, sulfide, nitride, hydride, peroxide, hydroxide, cyanide, perchlorate, chlorate, chlorite, hypochlorite, nitrate, nitrite, sulfate, sulfite, phosphate , carbonate, acetate, oxalate, tosylate, cyanate, thiocyanate, bicarbonate, permanganate, chromate and dichromate. 5. The method of claim 4, wherein the quaternary amine compound has a number average molecular weight of 700 or less. 6. The method according to p. 1 or 3, in which the modifier of electrostatic properties contains an imidazoline compound selected from a compound of formula (IIa)

where each R ′ _{4 is} independently selected from a representative selected from the group consisting of C ₁ -C ₄ alkylamine, C ₁ -C ₄ alkoxy and C ₂ -C ₅ alkyl; and where R _{4 is} selected from a representative selected from the group consisting of H, C ₁ -C ₂₆ alkyl, C ₂ -C ₂₆ alkenyl, C ₆ -C ₂₆ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C ₁₈ naphthylalkyl , or its quaternized salt;
compounds of formula (IIb)

in which R _{1 is} selected from a representative of the group consisting of H, C ₁ -C ₂₆ alkyl, C ₂ -C ₂₆ alkenyl, C ₆ -C ₂₆ aryl, C ₇ -C ₁₀ aralkyl, C ₁₀ -C ₁₈ naphthylalkyl and oleyl; and where R in formula (IIb) is selected from a representative selected from the group consisting of H, C ₁ -C ₂₆ alkyl, oleyl, C ₂ -C ₂₆ alkenyl, C ₆ -C ₂₆ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C ₁₈ naphthylalkyl; or
mixtures of a compound of formula (IIa) or a quaternized salt thereof with a compound of formula (IIb). 7. The method of claim 1 or 3, wherein the electrostatic modifier comprises a dithiocarbamate compound. 8. The method according to p. 7, in which the dithiocarbamate compound is a sodium diallylamine dithiocarbamate of the formula (VII):

9. The method according to p. 1 or 3, in which the modifier of electrostatic properties contains a pyridine compound of the formula (III):

where R in the formula (III) is selected from a representative selected from the group consisting of H, C ₁ -C ₂₂ alkyl, C ₆ -C ₂₂ aryl, C ₇ -C ₁₀ aralkyl and C ₁₀ -C ₁₈ naphthylalkyl; and
where X in the formula (III) is selected from a representative selected from the group consisting of halide, oxide, sulfide, nitride, hydride, peroxide, hydroxide, cyanide, perchlorate, chlorate, chlorite, hypochlorite, nitrate, nitrite, sulfate, sulfite, phosphate , carbonate, acetate, oxalate, tosylate, cyanate, thiocyanate, bicarbonate, permanganate, chromate and dichromate. 10. The method according to p. 1 or 3, in which the modifier of electrostatic properties contains a polyaniline compound of the formula (V):

where each of X, Y, and Z in formula (V) is individually selected from a representative selected from the group consisting of —COOH, —SO ₃ H and —CO (NH — OH);
where R _{7 is} selected from a representative selected from the group consisting of H, C ₁ -C ₂₂ alkyl, C ₆ -C ₂₂ aryl, C ₇ -C ₁₀ aralkyl, C ₁₀ -C ₁₈ naphthylalkyl, sulfate and hydroxyl; and
where n in the formula (V) is selected so that the polyaniline has a number average molecular weight in the range of 500 to 10,000. 11. A method according to Claim. 1 or 3, wherein the electrostatic properties of the modifier is a compound of formula (IV) and wherein it is selected from C ₁ -C ₁₀ alkilgidroksamatov or their salts. 12. The method according to p. 1 or 3, in which the modifier of electrostatic properties is a polyethyleneimine compound of the formula (VIII)

where n in the formula (VIII) is selected so that polyethyleneimine has a number average molecular weight in the range of 350 to 1000, or a mixture thereof. 13. The method according to p. 1 or 3, in which the reagent for modifying the electrostatic properties is mixed with a mineral substrate in an amount that is from 0.01 kg to 5 kg of a modifier of electrostatic properties per ton of mineral substrate. 14. The method according to p. 2, in which many particles are mixed with a mineral substrate with a ratio in the range from 0.01 kg to 5 kg of particles per ton of mineral substrate. 15. The method according to p. 2 or 14, in which the mass ratio of the modifier of electrostatic properties to particles is from 100: 1 to 1: 100. 16. The method according to p. 2 or 14, in which many particles are non-conductive and are selected from a representative selected from the group consisting of silicates, aluminates, polystyrene, quartz, mica, talc, rubber, shellac, lucite, glass, wood, celluloid , ivory and mixtures thereof. 17. The method according to p. 16, in which silicates have the formula (M _x O _y ) _p (SiO ₂ ) _q and aluminates have the formula M _x AlO _z ; where M is a metal; each of x and y individually ranges from about 1 to 4; z ranges from 1 to 12; and the p: q ratio is in the range from 10: 1 to 1:10. 18. The method of claim 16, wherein the non-conductive particles comprise aluminosilicate clay. 19. The method according to p. 2, in which many particles have an average diameter of from 1 to 500 microns. 20. The method of claim. 2 or 19, wherein the plurality of particles are conductive and comprise a metal oxide of formula M _x O _y, wherein M is a transition metal, and wherein each of x and y, individually, in the range of 1 to 6. 21. The method according to p. 20, in which the transition metal is selected from a representative selected from the group consisting of Cu, Co, Mn, Ti, Fe, Zn, Mo, and Ni. 22. The method according to p. 2 or 19, in which many particles are conductive and contain a superconducting material of the formula A _p B _q D _r O _s , where A is selected from a representative selected from the group consisting of La, Pr, Ce, Nd, Sm, Eu, Gd, Ho, Er, Tm, Yb, Lu and Nb, where p is in the range from 0.01 to 2.0;
B is selected from Ca, Ba, or Sr, where q is in the range from 0.5 to 3;
D is selected from Cu, Ni, Ti or Mo, where r is in the range from 0.1 to 5;
O represents oxygen, and s is in the range from 1 to 10. 23. The method according to p. 2 or 3, in which the modifier of electrostatic properties is selected from a representative selected from the group consisting of quaternary amines; imidazoline compounds; dithiocarbamate compounds; pyridine compounds; pyrrolidine compounds; conductive polymers; polyethyleneimines and mixtures thereof, and in which many particles are non-conductive particles. 24. The method according to p. 1 or 2, in which the mineral substrate contains minerals containing rutile and zircon. 25. The method of claim 6, wherein the imidazoline compound is selected from
the compounds of formula (IIa) in which R ′ ₄ represents C ₁ -C ₄ alkoxy, and R ₄ represents C ₁ -C ₂₆ alkyl;
a compound of formula (IIb) in which R is oleyl and R ₁ is oleyl; or
their mixtures. 26. The method of claim 16, wherein the plurality of non-conductive particles are zirconium silicate ZrSiO ₄ . 27. The method of claim 17, wherein the plurality of non-conductive particles are zirconium silicate ZrSiO ₄ . 28. The method of claim 11, wherein the alkyl hydroxamate is selected from the group consisting of mono-, di- and trihydroxamic acids, their sodium salts, their potassium salts, or mixtures thereof. 29. The method of claim 25, wherein the compound of formula (IIa) is

30. The method of claim 25, wherein the compound of formula (IIb) is