阅读说明：本技术 用于矿石选矿的选择性多糖试剂和絮凝剂 (Selective polysaccharide reagents and flocculants for ore beneficiation ) 是由 S.卡波 M.M.达科斯塔 X.殷 于 2018-02-07 设计创作，主要内容包括：选择性多糖试剂或絮凝剂包含一种或多种类型的多糖,所述多糖包含一种或多种类型的戊聚糖单元。还公开了用于从包含所需矿物和脉石和/或其他矿物的矿石富集所需矿物的方法,其中所述方法包括使用一种或多种选择性多糖试剂或絮凝剂在水性介质中处理矿石,所述选择性多糖试剂或絮凝剂包含一种或多种类型的多糖,所述多糖包含一种或多种类型的戊聚糖单元。(The selective polysaccharide agent or flocculant comprises one or more types of polysaccharides comprising one or more types of pentosan units. Also disclosed is a method for enriching a desired mineral from an ore comprising the desired mineral and gangue and/or other minerals, wherein the method comprises treating the ore in an aqueous medium with one or more selective polysaccharide agents or flocculants comprising one or more types of polysaccharides comprising one or more types of pentosan units.)

1. A method for enriching a desired mineral or material from an ore having an iron-containing material and/or a silicate-containing gangue, the method comprising treating the ore in an aqueous medium with one or more selective polysaccharide agents or flocculants comprising one or more types of pentosan units.

2. The method of claim 1, wherein the desired mineral is an iron-containing mineral.

3. The method of claim 1, wherein the gangue comprises oxides, silicates or siliceous materials of silica.

4. The method of claim 1, wherein the method comprises the steps of:

(i) mixing the ground ore with a solvent to form a mixture;

(ii) adding the one or more selective polysaccharide agents or flocculants to the mixture;

(iii) agitating the mixture to disperse the selective polysaccharide agent or flocculant;

(iv) allowing flocs to form; and

(v) the flocs are separated.

5. The process of claim 1, wherein the one or more selective flocculants are added to a tailings stream.

6. A process for enriching or facilitating recovery of a desired mineral from a tailings stream comprising the desired mineral and gangue and/or other minerals, wherein the process comprises treating the tailings stream with one or more selective polysaccharide agents or flocculants comprising one or more types of polysaccharides comprising one or more types of pentosan units.

7. The process of claim 6, wherein the tailings stream is a tailings stream of a desliming process.

8. The process of claim 6, wherein the tailings stream is a tailings stream of a flotation process.

9. The process of claim 6, wherein the tailings stream comprises an iron-containing mineral.

10. The method of claim 6, wherein the gangue comprises oxides, silicates or siliceous materials of silica.

11. The process of claim 1 or 6, wherein the one or more selective polysaccharide agents or flocculants are added in the form of a composition comprising the selective polysaccharide agent or flocculant and a solvent.

12. The method of claim 11, wherein the solvent is water.

13. The method of claim 1, wherein the method comprises a beneficiation process.

14. The method of claim 1, wherein the method comprises a flotation process.

15. The method of claim 1, wherein the method comprises a flocculation process.

16. The method of any one of the preceding claims, wherein the one or more types of polysaccharides are derived from one or more types of lignocellulosic biomass.

17. The method of any one of the preceding claims, wherein the lignocellulosic biomass is selected from the group consisting of: herbaceous crops, wood and agricultural residues.

18. The method of any one of the preceding claims, wherein the agricultural residue is selected from the group consisting of: bagasse, wheat straw, corn stover, corn fiber, and mixtures thereof.

Technical Field

The present invention relates to selective polysaccharide reagents and flocculants for ore beneficiation.

Background

Although iron is the fourth most abundant element in the earth's crust, most is bound in silicates or the less common carbonate minerals. The thermodynamic barrier to the separation of pure iron from these minerals is difficult and energy intensive, and therefore common iron sources used in industry use relatively rare high grade iron oxide minerals, mainly hematite. Most of the reserves of such high grade ores are now exhausted, resulting in the development of lower grade iron ore sources such as magnetite and taconite. The iron content of these lower grade ores can be concentrated (upgraded) to higher iron contents by various concentration (beneficiation) processes, for example to meet the quality requirements of the iron and steel industry.

In the face of the reduction of the reserves of high-grade iron ores, the tonnage of lower-grade iron ores which are greatly increased are expected to be recovered in the foreseeable future. The treatment of lower grade ore sources involves the removal of unwanted minerals (such as silicates and carbonates), which are an intrinsic part of the ore-bearing rock itself (gangue). In these beneficiation processes, gangue is separated using techniques such as crushing, grinding, crushing, gravity or heavy media separation, screening, magnetic separation, and/or froth flotation to increase the concentration of the desired minerals and remove impurities.

Despite the increased recovery and concentration of the desired mineral provided by various beneficiation processes, loss of valuable ore can still occur during processing, for example, at a desliming stage (e.g., by filtration, settling, siphoning, or centrifugation) for removal of the finest fraction of the particles. A significant amount of fine particulate valuable ore that remains dispersed may be lost in the slurry portion. That part of the one or more value minerals which is unintentionally removed with the slime part may be permanently lost from the process. Even a small increase in the recovery or grade of the desired mineral or minerals may result in significant economic benefits.

In an effort to improve the recovery of valuable ores, improved flotation systems have been developed which involve pre-treating the ore by dispersing the finely ground ore in an aqueous medium and first subjecting it to a selective flocculation process. After the selective flocculation stage, the system is deslimed to remove silica-containing fines, and then the flocculated iron-containing residue is concentrated to final grade by flotation and removal of non-ferrous siliceous material. In selective flocculation, a flocculant is added before the flotation and desliming stages and is selective in its flocculation properties in order to achieve separation between mineral species contained in the aqueous dispersion. In an oxidized iron ore system, a selective flocculant causes flocculation of iron-containing particles while suspending non-ferrous siliceous material.

Selective flocculants currently known in the art include tapioca, potato starch, natural and modified starches, as well as polyacrylamides and synthetic flocculants such as those taught by U.S. patent No. 3,292,780 to Frommer et al, U.S. patent No. 4,081,357 to Werneke et al, U.S. patent No. 4,274,945, and european patent No. 0232679B 1.

Brief description of the drawings

In view of the foregoing, one or more embodiments described herein include a method for enriching a desired mineral or material from an ore having an iron-containing material and/or a silicate-containing gangue, the method comprising treating the ore in an aqueous medium with one or more selective polysaccharide agents or flocculants comprising one or more types of pentosan units. Also described herein are methods for enriching or facilitating recovery of a desired mineral from a tailings stream comprising the desired mineral and gangue and/or other minerals, wherein the methods comprise treating the tailings stream with one or more selective polysaccharide agents or flocculants.

The present disclosure may be understood more readily by reference to the following detailed description of various features of the disclosure and the examples included therein.

Detailed Description

According to various embodiments described herein, selective polysaccharide reagents may be used to improve the grade and/or recovery of value minerals from mineral-containing ores. In certain embodiments, the methods use selective polysaccharide reagents to selectively flocculate mineral values to facilitate separation of desired mineral values from gangue or other mineral-containing ores. In certain embodiments, the selective polysaccharide reagent can be used to selectively flocculate oxidized iron ore from its associated siliceous gangue. In some embodiments, the selective polysaccharide agent may also be used to facilitate the separation of niobium from iron and niobium containing ores.

In embodiments, the method comprises dispersing the ground ore in an aqueous medium (e.g., a slurry) and adding an effective amount of one or more of the selective polysaccharide agents or flocculants described herein. In embodiments, the selective polysaccharide agent or flocculant comprises one or more types of polysaccharides comprising one or more types of pentosan units. In certain embodiments, the ground ore is ore fines, or ore comprised of particles less than about 10 microns.

In embodiments, the selective polysaccharide agents or flocculants, compositions and methods may be used to provide improved selectivity for a desired mineral as compared to other agents or flocculants such as starch or caustic starch. In particular, the selectivity agent or flocculant may provide increased desliming selectivity, reduced loss of valuable ore fines, reduced sodium hydroxide consumption, and/or reduced landfill, particularly as compared to starch-based flocculants.

Definition of

As used herein, "gangue" or "siliceous gangue" refers to unwanted minerals in a material (e.g., a deposit containing both unwanted and desired minerals). Such undesirable minerals may include oxides of iron, aluminum, silica (e.g., quartz), titanium, sulfur, and alkaline earth metals, among others. In certain embodiments, the gangue comprises oxides of silica (e.g., SiO)₂Or quartz), silicate or siliceous materials,such as kaolinite, muscovite, montmorillonite, and the like.

As used herein, the term "desired mineral" or "valuable mineral" refers to any mineral (naturally occurring solid inorganic material) that is of value, particularly extractable from an ore containing the desired mineral and gangue. In certain embodiments, the desired mineral may be iron powder, hematite, magnetite, pyrite, chromite, goethite, marcasite, limonite, pyrrhotite, or any other iron-containing mineral. In certain embodiments, the desired mineral comprises a mineral in an iron-containing ore, such as niobium. In certain embodiments, the desired mineral is derived from a multimetallic sulfide ore, wherein the desired mineral may comprise one or more metals, such as copper, lead, zinc, iron, molybdenum, gold, or silver. In certain embodiments, the iron in the mineral is not a desired mineral.

As used herein, "ore" refers to rocks and other deposits from which a desired mineral can be extracted. Other sources of the desired mineral may be included in the definition of "ore" depending on the nature of the desired mineral. The ore typically contains unwanted minerals or materials (also referred to herein as gangue).

As used herein, "iron ore" refers to rocks, minerals, and other iron sources from which metallic iron can be extracted. The ore is usually rich in iron oxides, ranging in color from dark gray, bright yellow, dark purple to rusty red. The iron is usually magnetite (Fe)₃O₄) Hematite (Fe)₂O₃) Goethite (FeO (OH)), limonite (FeO (OH))₂O)), siderite (FeCO)₃) Or pyrite (FeS)₂) Exist in the form of (1). Taconite is a ferric sedimentary rock in which iron minerals are layered with quartz, flint or carbonate. Iron brities, also known as banded quartzite and hematite schist, are a form of iron and quartz rock in which iron exists as a thin layer of hematite, magnetite or pseudohematite. Any of these types of iron are suitable for use in the methods described herein. In embodiments, the iron ore is substantially magnetite, hematite, taconite, or allophonite. In an embodiment, the iron ore is substantially pyrite. In embodiments, ironThe ore is contaminated with gangue materials, such as oxides of aluminum, silica or titanium. In embodiments, the iron ore is contaminated with gangue. In embodiments, the iron ore is contaminated with clays, including, for example, kaolinite, muscovite or other silicates.

As used herein, "pH adjusting agent (pH adjuster)", "pH adjusting agent (pH adjusting agent)" or "pH adjusting agent (pH regulator)" refers to an agent for changing or controlling pH. Any suitable agent for altering or controlling the pH may be used including, for example, sodium hydroxide or ammonium hydroxide.

As used herein, the terms "polymer", "polymers", "polymerized" and similar terms are used in their conventional sense as understood by those skilled in the art and thus may be used herein to refer to or describe a macromolecule (or a group of such molecules) containing repeating units. The polymer may be formed in various ways, including by polymerizing monomers and/or by chemically modifying one or more repeat units of a precursor polymer. Unless otherwise specified, a polymer may be a "homopolymer" comprising substantially identical repeating units, formed, for example, by polymerizing a particular monomer. Unless otherwise indicated, the polymer may also be a "copolymer" comprising two or more different repeat units, formed, for example, by copolymerizing two or more different monomers and/or by chemically modifying one or more repeat units of the precursor polymer. Unless otherwise indicated, the polymer may also be a "terpolymer" comprising three or more different repeating units.

As used herein, "agent," "selective agent," or "selective polysaccharide agent" refers to an agent that facilitates the separation of a desired mineral from gangue and/or other minerals. In particular, the reagent selectively enriches one fraction containing the desired mineral separated from the beneficiation, flotation, or flocculation process, while a second fraction is enriched in gangue. In embodiments, the selective flocculant is an agent that selectively enriches one fraction containing iron or iron oxides separated from a beneficiation, flotation, or flocculation process, while a second fraction is enriched in gangue. In embodiments, a selective flocculant is an agent that selectively enriches one fraction separated from a beneficiation, flotation, or flocculation process, while a second fraction containing iron or iron oxides is enriched in gangue.

As used herein, "flocculant", "selective flocculant" or "selective polysaccharide flocculant" refers to an agent that promotes agglomeration of particles in a suspension (e.g., a dispersed suspension). In particular, the selective flocculant selectively enriches one fraction containing the desired mineral separated from a beneficiation, flotation, or flocculation process, while a second fraction is enriched in gangue. In embodiments, the selective flocculant is an agent that selectively enriches one fraction containing iron or iron oxides separated from a beneficiation, flotation, or flocculation process, while a second fraction is enriched in gangue. In embodiments, a selective flocculant is an agent that selectively enriches one fraction separated from a beneficiation, flotation, or flocculation process, while a second fraction containing iron or iron oxides is enriched in gangue.

As used herein, the term "polysaccharide" refers to a carbohydrate molecule of repeating monomeric (monosaccharide) units linked together by glycosidic bonds. The polysaccharides may differ in structure, for example, they may be linear or branched. The molecule may contain slight modifications of the repeat unit. Monosaccharides are typically aldehydes or ketones having two or more hydroxyl groups. Polysaccharides containing a single type of monosaccharide unit are referred to as homopolysaccharides, while polysaccharides containing more than one type of monosaccharide unit are referred to as heteropolysaccharides. Polysaccharides are generally considered to contain 10 or more monosaccharide units, while the term "oligosaccharides" is generally used to refer to polymers containing a small number (e.g., 2-10) of monosaccharide units.

As used herein, "hemicellulose" refers to the heteropolymeric polysaccharide component of plant cell walls other than cellulose. Hemicellulose has a sugar called pentose, such as xylose, each having 5 carbon atoms as a constituent unit; sugars known as hexoses, such as mannose, arabinose, and galacturonic acid, each having 6 carbon atoms as a constituent unit; and, optionally, complex polysaccharides such as glucomannan and glucuronoxylan. Hemicellulose can be any of several heteropolymers present in almost all plant cell walls, for example, xylan, arabinoxylan, glucuronoxylomannan. Typically, the backbone (i.e., backbone) is comprised of β -1, 4-linked D-xylopyranose residues. In addition to xylose, hemicellulose may also contain arabinose, glucuronic acid or its 4-O-methyl ether, and acetic acid, ferulic acid and p-coumaric acid. In some cases, the monomer branches off from the xylan backbone. The frequency and composition of the bifurcation depends on the source. All types of hemicellulose may be used in embodiments.

As used herein, the term "starch" refers to a carbohydrate composed of a large number of glucose units joined by glycosidic bonds. It is recognized that starch polymers are composed primarily of two parts, amylose and amylopectin, which vary with the source of the starch. Amylose with a low molecular weight contains one terminal group per 200-300 anhydroglucose units. Amylopectin has a higher molecular weight and consists of more than 5,000 anhydroglucose units, with one end group per 20-30 glucose units. While amylose is an amylose polymer with alpha 1 → 4 carbon linkages, amylopectin is a highly branched polymer with alpha 1 → 4 and alpha 1 → 6 carbon linkages at the branching points.

As used herein, the term "slime" or "slime" refers to an aqueous composition that includes fine particles, such as particles less than about 10 microns. The slimes may be produced in a grinding stage of an ore beneficiation process, which is necessary to individually treat mineral species for a subsequent concentration process. However, some ore samples naturally contain fine particles. Desliming processes are used to remove very fine particles, including clay, phosphorus, aluminum, calcium, manganese, and iron compounds, from the slurry prior to a flotation process, such as reverse cationic flotation.

Selective polysaccharide reagents or flocculants

In embodiments, the one or more selective polysaccharide reagents may be selective in the beneficiation, flotation, or flocculation of metal ores (particularly iron ore or other desired minerals). In embodiments, the one or more selective polysaccharide agents may facilitate the separation of a desired mineral from gangue or other minerals in an aqueous medium. In certain embodiments, the one or more selective polysaccharide flocculants may facilitate the separation of a desired mineral from iron, iron oxides, and/or gangue in an aqueous medium. In embodiments, the amount of separation or isolation obtained is at least about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, or about 90% of the desired mineral in the aqueous medium. In embodiments, the amount of separation or isolation obtained is in the range of about 40% to about 90%, about 40% to about 60%, or about 45% to about 55% of the desired mineral in the aqueous medium.

In embodiments, the one or more selective flocculants may be selective in the flocculation of an ultra-fine aqueous dispersion of a metal ore (particularly iron ore or other desired mineral). In certain embodiments, the one or more selective flocculants do not substantially flocculate the gangue materials. The simultaneous presence of the desired minerals that can be separated by flocculating the gangue material does not significantly alter the flocculation potential of the minerals. In embodiments, the amount of flocculation obtained is at least about 40%, about 45%, about 50%, about 55%, about 60%, about 65%, about 70%, about 75%, about 80%, about 85%, or about 90% of the desired mineral in the aqueous medium. In embodiments, the amount of flocculation obtained is in the range of from about 40% to about 90%, from about 40% to about 60%, or from about 45% to about 55% of the desired mineral in the aqueous medium.

In embodiments, the selective polysaccharide agent comprises one or more types of polysaccharides comprising one or more types of pentosan units.

In certain embodiments, the selective agent or flocculant has one or more types of polysaccharides comprising one or more types of pentosan units.

Pentosan units are monosaccharides with 5 carbon atoms, including, for example, xylose, ribose, arabinose, and lyxose. In certain embodiments, the pentosan unit can be an aldopentose having an aldehyde functional group at position 1, such as the D-or L-forms of arabinose, ribose, xylose, and lyxose. Polysaccharides include, for example, xylan, hemicellulose, and gum arabic.

Hemicelluloses are derived from lignocellulosic biomass, including, but not limited to: for example herbaceous crops, for example grasses, such as switchgrass; wood, for example hardwood, such as pine, poplar, and spruce; and agricultural residues such as bagasse, wheat straw, corn stover (which may include the stems, leaves, husks and corn cobs of corn plants), corn fiber (corn bran or corn husks). In embodiments, the hemicellulose may contain a mixture of xylose, arabinose, mannose and galactose. Thus, any plant material comprising hemicellulose can be used to prepare a selective polysaccharide agent or flocculant. In certain embodiments, the one or more selective polysaccharide agents or flocculants comprise hemicellulose. In certain embodiments, the one or more selective polysaccharide agents or flocculants comprise a polysaccharide derived from one or more types of lignocellulosic biomass.

The gum arabic may contain arabinose and ribose. In embodiments, the one or more types of pentosan units comprise xylan units and one or more of hemicellulose and aldopentose.

In particular embodiments, the one or more selective polysaccharide agents or flocculants are derived from a waste product of an industrial process. In certain embodiments, the one or more selective polysaccharide agents or flocculants are derived from corn fiber, corn stover, and mixtures thereof.

Corn fiber comprises a matrix of hemicellulose, cellulose, and lignin. Any corn fiber can be used in the methods of the invention, including natural corn fibers and corn fibers produced by standard breeding techniques, including crossbreeding, translocation, inversion, transformation, or any other method of genetic or chromosomal engineering to include variations thereof. Native corn is intended to refer to those varieties found in nature, including dent corn, waxy corn, or high amylose corn. In embodiments, the corn fiber may be obtained from a wet or dry milling process. Thus, corn fiber may be wet or dry. In embodiments, the corn fiber may be dried and stored prior to use in the preparation of the polysaccharide agent or selective flocculant. The corn fiber may be a de-starched corn-fiber. The de-starched corn fiber is typically formed by liquefaction using an alpha-amylase until at least a portion is soluble. Other methods of de-starching known in the art are also suitable, including separating the starch from the fiber, i.e., by a hydrocyclone, or by using other enzymes or combinations thereof.

In embodiments, the one or more types of polysaccharides are derived from algae. In certain embodiments, the one or more types of polysaccharides are not derived from algae.

In embodiments, the selective polysaccharide agent or flocculant may be a blend or mixture of polysaccharides having one or more types of pentosan units. In certain embodiments, the selective polysaccharide agent or flocculant may consist essentially of a polysaccharide comprising one type of pentosan units (e.g., xylan). In certain embodiments, the one or more types of pentosan units comprise xylan. In embodiments, a selective polysaccharide agent or flocculant comprising one or more types of polysaccharides comprising xylan units is provided.

In embodiments, the xylan-comprising polysaccharide may be extracted from plant material (e.g., lignocellulosic biomass) or from algae using a dilute alkaline solution, e.g., as described in international publication No. WO 2014/055502.

Xylan is an oligosaccharide that can be extracted in the form of 5-200 anhydroxylose units consisting of D-xylose units with a 1 β → 4 linkage.

Xylan-oligosaccharides with 5-200 anhydroxylose units consisting of D-xylose units with a 1 β → 4 linkage

In embodiments, polysaccharides comprising one or more types of pentosan units may be extracted from pulp black liquor, from Cold Caustic Extraction (CCE) filtrate, and/or from acid prehydrolysis or autohydrolysis processes to achieve dissolving pulp grades. Such extraction is described, for example, in Jayapal et alIndustrial Crops and Products2012，v. 42, pages 14-24; of Muguet et alHolzforschung2011, v.65, pp. 605-612; and Gehmayer et alBiomacromolecules2012, v.13, page 645-651.

In certain embodiments, the selective polysaccharide agent or flocculant does not comprise a significant amount of arabinose or ribose, or a source thereof.

In embodiments, the molecular weight of the selective polysaccharide agent or flocculant is from about 700 to about 50,000; about 700 to about 25,000; or from about 700 to about 8000 daltons. In embodiments, the molecular weight of the selective polysaccharide agent or flocculant is from about 5 to about 300, from about 5 to about 150, or from about 5 to about 50 aldopentose units, such as xylose units.

In embodiments, the selective agent can have any molecular weight, so long as the selective agent has the effect of selectively flocculating the desired mineral in preference to flocculating the associated gangue. In certain embodiments, the selective agent may have any molecular weight, so long as the selective agent has the effect of selectively flocculating iron or iron oxides in preference to other minerals. In embodiments, the selective flocculant has a molecular weight of about 700 to about 50,000; about 700 to about 25,000; or from about 700 to about 8000 daltons. In embodiments, the selective flocculant has a molecular weight of about 5 to about 300, about 5 to about 150, or about 5 to about 50 aldopentose units, such as xylose units.

Composition comprising a metal oxide and a metal oxide

In embodiments, the composition comprises one or more selective polysaccharide agents or flocculants and a solvent as described herein. In embodiments, the composition comprises one or more selective flocculants and a solvent as described herein. In embodiments, the composition comprises one or more selective flocculants and a solvent, wherein the one or more selective flocculants is one or more of the selective flocculants described herein.

In embodiments, the solvent is water. In embodiments, the composition is a solution, e.g., an aqueous solution.

In embodiments, the composition is a gel, such as a polysaccharide gel. In embodiments, the gel is water soluble.

The composition according to embodiments may be formulated to provide a sufficient amount of the one or more selective flocculants prior to the desliming process, i.e., an amount sufficient to produce the desired result.

In embodiments, the composition may further comprise one or more agents or modifiers known in the art of desliming, such as dispersants. Examples of such agents or modifiers include, but are not limited to, sodium silicate and/or polyacrylic acid based dispersants, or any other agent known in the art. Dispersants suitable for use in combination with the selective polysaccharide agent or flocculant are not particularly limited and include: kemceal^TMTC2500 (sodium silicate and polyacrylic acid dispersant available from Kemira Chemicals, inc.), sodium polyphosphate, and the like.

In embodiments, the compositions may be used in processes where one or more agents or modifiers (e.g., dispersants) known in the art of desliming are added separately.

In embodiments, the composition includes one or more conventional selective flocculants or flocculants not included in the embodiments described herein. Other selective flocculants that may be used in combination with the polysaccharide agent or flocculant include, but are not limited to: starches, such as tapioca, corn, potato, wheat, rice, and the like; treating the activated starch with alkali; cellulose esters such as carboxymethyl cellulose and sulfomethyl cellulose; cellulose ethers such as methyl cellulose, hydroxyethyl cellulose and ethyl hydroxyethyl cellulose; hydrophilic gums such as gum arabic, gum karaya, gum tragacanth and gum ghatti; an alginate; starch derivatives such as carboxymethyl starch and phosphate starch; and combinations thereof.

Method of producing a composite material

In certain embodiments, a method of enriching a desired mineral or material from an ore having an iron-containing material and/or a silicate-containing gangue comprises treating the ore in an aqueous medium using one or more selective polysaccharide agents or flocculants described herein. In certain embodiments, a method for enriching an iron-containing mineral from an ore having an iron-containing material and a silicate-containing gangue comprises treating the ore in an aqueous medium using one or more selective polysaccharide agents or flocculants described herein. In embodiments, the method comprises, or consists of, a beneficiation process. In embodiments, the method comprises, or consists of, a flotation process. In embodiments, the method comprises a flocculation process.

In certain embodiments, the method comprises the steps of:

(i) mixing the ground ore with a solvent to form a mixture;

(ii) adding one or more selective polysaccharide agents or flocculants to the mixture;

(iii) agitating the mixture to disperse the selective polysaccharide agent or flocculant;

(iv) allowing flocs to form; and

(v) the flocs are separated.

In embodiments, the selective beneficiation, flotation, or flocculation process comprises dispersing ground ore in an aqueous medium to form a mixture, and adding to the mixture one or more selective polysaccharide agents or flocculants described herein. In embodiments, an effective amount of one or more selective polysaccharide agents or flocculants is added to the mixture. In embodiments, the one or more selective polysaccharide agents or flocculants added to the mixture comprise one or more types of polysaccharides comprising one or more types of pentosan units. In embodiments, an effective amount of one or more selective polysaccharide agents or flocculants is added to the mixture. In certain embodiments, the ground ore is ground iron ore or ground iron ore contaminated with gangue. In certain embodiments, the ground ore is an ore containing niobium or an ore containing niobium and iron. In embodiments, the ground ore is a polymetallic sulphide ore containing a desired mineral, wherein the desired mineral comprises two or more metals selected from the group consisting of copper, lead, zinc, iron, molybdenum, gold and silver. In certain embodiments, the ground ore is a multi-metal sulfide ore containing two or more metals selected from copper, lead, zinc, iron, molybdenum, gold, and silver. In certain embodiments, the ground ore is a multimetallic sulfide ore comprising iron and one or more metals selected from the group consisting of copper, lead, zinc, iron, molybdenum, gold, and silver.

In embodiments, the selective flocculation process comprises dispersing the ground ore in an aqueous medium to form a mixture, and adding to the mixture one or more selective flocculants described herein. In embodiments, an effective amount of one or more selective flocculants is added to the mixture. In embodiments, the one or more selective flocculants added to the mixture comprise one or more types of polysaccharides comprising one or more types of pentosan units. In embodiments, an effective amount of one or more selective flocculants is added to the mixture. In certain embodiments, the ground ore is ground iron ore or ground iron ore contaminated with gangue. In certain embodiments, the ground ore is an ore containing niobium or an ore containing niobium and iron. In embodiments, the ground ore is a polymetallic sulphide ore containing a desired mineral, wherein the desired mineral comprises two or more metals selected from the group consisting of copper, lead, zinc, iron, molybdenum, gold and silver. In certain embodiments, the ground ore is a multi-metal sulfide ore containing two or more metals selected from copper, lead, zinc, iron, molybdenum, gold, and silver. In certain embodiments, the ground ore is a multimetallic sulfide ore comprising iron and one or more metals selected from the group consisting of copper, lead, zinc, iron, molybdenum, gold, and silver.

In embodiments, the method further comprises intensively mixing the mixture after the one or more selective polysaccharide agents or flocculants have been added to the mixture to ensure uniform distribution of the selective polysaccharide agent or flocculant throughout the mixture.

In embodiments, the method further comprises intensively mixing the mixture after the one or more selective flocculants have been added to the mixture to ensure a uniform distribution of the selective flocculant throughout the mixture.

In embodiments, the method further comprises allowing the iron values to separate or settle from the mixture. In certain embodiments, the iron value may settle out of the mixture as an underflow concentrate while the siliceous gangue material remains suspended in the supernatant. In certain embodiments, the iron value may settle out of the mixture as an underflow concentrate while the desired mineral material remains suspended in the supernatant. Typically, effective settling is achieved within about 30 minutes or in the range of about 5 to about 30 minutes after the selective flocculant or flocculants have been added and mixed homogeneously into the ore dispersion, however, the specific settling time is not considered critical and can vary widely depending on the particular ore being treated, the polymer composition used, the polymer dosage applied, and the like.

In embodiments, the method further comprises recovering the desired material or mineral. This desired mineral or material may be in the form of a concentrate. The recovery step is generally carried out after the mixture has settled sufficiently. The operation may be performed in accordance with any conventional procedure while using any conventional equipment associated with such procedures. In some embodiments, a desliming technique, such as decantation of the supernatant, is followed by an additional flotation step to enhance the separation and/or recovery of the desired mineral. In some embodiments, decantation of the supernatant and an additional flotation step to enhance separation and/or recovery of the desired mineral. In some embodiments, the procedure is decantation of the supernatant or any other known desliming technique, followed by a flotation step in which the remaining siliceous gangue is removed by froth flotation, leaving behind iron values. In some embodiments, the procedure is decantation of the supernatant or any other known desliming technique, followed by a flotation step in which the remaining desired materials or minerals are removed by froth flotation, leaving behind iron values.

In embodiments, the selective beneficiation, flotation, or flocculation process results in the separation (isolation) or separation (separation) of the desired minerals from the gangue and facilitates recovery of the desired minerals. Using the methods according to embodiments, very high yields of the desired material or mineral are recovered, for example at least about 70%, about 75%, about 80%, about 85%, about 90%, or about 95% recovery of the desired material or mineral. In embodiments, the selective beneficiation, flotation, or flocculation process results in the separation (isomerization) or separation (segregation) of iron from ore. Using the method, iron can be separated and recovered from ore, e.g., at least about 70%, about 75%, about 80%, about 85%, about 90%, or about 95% recovery of iron or iron-containing minerals.

In certain embodiments, the selective flocculation process results in selective flocculation of the desired minerals when compared to flocculation of gangue to facilitate separation and recovery of the desired minerals. In certain embodiments, the selective flocculation process results in selective flocculation of iron when compared to flocculation of the desired mineral to facilitate separation and recovery of the desired mineral.

An "effective amount" of a selective polysaccharide agent or flocculant refers to an amount of the selective polysaccharide agent or flocculant that is effective to produce a desired degree of separation (isolation) or separation (separation) of a desired mineral or metal value from gangue or other minerals, which results in a desired degree of recovery of the desired mineral or metal value. The particular amount effective will vary depending on variables such as the particular ore being treated, the particular composition of the one or more selective polysaccharide agents or flocculants, the degree of dispersion, the particle size, etc. In some embodiments, the effective amount ranges from about 0.1 to about 2.0 pounds, or about 0.1 to about 0.5 pounds, of selective polysaccharide agent or flocculant per ton of ore processed. According to alternative embodiments, the effective amount of the selective polysaccharide agent or flocculant used in the beneficiation, flotation, or flocculation process is about 1,000 to about 0.01ppm, or about 500 to about 0.1ppm of the selective polysaccharide agent or flocculant in the beneficiation, flotation, or flocculation process. In embodiments, the effective amount of selective polysaccharide agent or flocculant in the process is from about 250 to about 1ppm, from about 150 to about 5ppm of flocculant, from about 150 to about 100 ppm of selective polysaccharide agent or flocculant, from about 100 to about 10ppm or from about 80 to about 15 ppm.

An "effective amount" of a selective flocculant refers to an amount of the selective flocculant effective to produce a desired degree of selective flocculation, which in turn results in a desired degree of recovery of metal values (e.g., iron ore). The particular amount effective will vary depending on variables such as the particular ore being processed, the particular composition of the one or more selective flocculants, the degree of dispersion, the particle size, and the like. In some embodiments, the effective amount ranges from about 0.1 to about 2.0 pounds, or about 0.1 to about 0.5 pounds, of selective flocculant per ton of ore processed. According to alternative embodiments, the effective amount of selective flocculant used in the flocculation process is about 1,000 to about 0.01ppm, or about 500 to about 0.1ppm, of flocculant in the flocculation process. In embodiments, the effective amount of flocculant in the process is about 250 to about 1ppm, about 150 to about 5ppm of flocculant, about 150 to about 100 ppm of flocculant, about 100 to about 10ppm or about 80 to about 15 ppm.

In an embodiment, a method for improving the grade of a desired mineral or substance comprises treating a mixture containing the desired mineral and gangue with one or more selective polysaccharide agents or flocculants described herein to produce the desired mineral and separating a desired mineral concentrate from the gangue.

In an embodiment, a method for improving the grade of a desired mineral or substance comprises selectively flocculating a mixture containing the desired mineral and gangue with one or more selective flocculants described herein to produce the desired mineral and separating a desired mineral concentrate from the gangue.

In embodiments, the desired mineral concentrate recovered from the processes described herein has an improved grade relative to the grade of the ore prior to selective flocculation. In certain embodiments, the desired mineral is an iron-containing mineral, such as iron oxide or iron powder. In certain embodiments, the desired mineral comprises niobium.

In embodiments, one or more selective polysaccharide agents or flocculants may be used prior to a desliming step (e.g., hydrocyclone desliming). In embodiments, a selective polysaccharide agent or flocculant may be added to the tailings stream of any of the processes described herein to enrich or facilitate recovery of a desired mineral or material from the tailings stream. Generally, "tailings" refers to the material left after the process of separating the valuable fraction from the uneconomic fraction.

In an embodiment, a method for enriching or facilitating recovery of a desired mineral from a tailings stream comprising the desired mineral and gangue and/or other minerals, wherein the method comprises treating the tailings stream with one or more selective polysaccharide agents or flocculants described herein.

In an embodiment, a method for enriching or facilitating recovery of a desired mineral from a tailings stream comprising the desired mineral and gangue and/or other minerals, wherein the method comprises conducting a flocculation process in the presence of one or more selective flocculants described herein.

In an embodiment, the tailings stream is a tailings stream of a desliming process. In an embodiment, the tailings stream is a tailings stream of a flotation process. In embodiments, the tailings stream comprises an iron-containing mineral. In embodiments, the tailings stream comprises an oxide, silicate, or siliceous material of silica. In certain embodiments, the tailings stream comprises from about 10 to about 50% iron-containing compounds. In certain embodiments, the tailings stream comprises niobium. In certain embodiments, the tailings stream comprises a multi-metal sulfide ore.

In an embodiment, a method for enriching a desired mineral from a tailings stream comprises the steps of:

(i) adding one or more selective polysaccharide agents or flocculants to a tailings stream to form a mixture;

(ii) agitating the mixture to disperse the one or more selective polysaccharide agents or flocculants;

(iii) allowing the flocs or layers to form; and

(iv) separating the floe or separating the layer.

In an embodiment, a method for enriching a desired mineral from a tailings stream comprises the steps of:

(i) adding one or more selective flocculants to a tailings stream to form a mixture;

(ii) agitating the mixture to disperse the one or more selective flocculants;

(iii) allowing flocs to form; and

(iv) the flocs are separated.

In embodiments, one or more selective polysaccharide agents or flocculants may be used to separate a desired mineral or material, such as niobium, from iron or iron-containing minerals in a tailings stream.

In embodiments, one or more selective polysaccharide agents or flocculants may be used to enrich an iron-containing mineral in a tailings stream containing an iron-containing ore, including magnetite, hematite, taconite, or allophane.

Other flocculants may be used in combination with the selective polysaccharide agent or flocculant, without particular limitation, including: starches, such as those derived from tapioca, corn, potato, wheat, rice, and the like; treating the activated starch with alkali; cellulose esters such as carboxymethyl cellulose and sulfomethyl cellulose; cellulose ethers such as methyl cellulose, hydroxyethyl cellulose and ethyl hydroxyethyl cellulose; hydrophilic gums such as gum arabic, gum karaya, gum tragacanth and gum ghatti; an alginate; starch derivatives such as carboxymethyl starch and phosphate starch; and combinations thereof. In certain embodiments, a selective polysaccharide agent or flocculant may be used in combination with a selective flocculant comprising a polymer comprising a) repeating units of one or more acrylamide monomers; b) repeating units of one or more monomers selected from the group consisting of hydroxyalkyl alkylacrylates, allyloxyalkyldiols, allyloxyethanols, trimethylolpropane allyl ether, and 2-hydroxyethyl acrylate; and optionally, c) repeating units of one or more acrylic monomers.

According to various embodiments, the amount of selective beneficiation or flotation can be quantified. For example, the amount of selective beneficiation or flotation can be quantified in terms of a percentage improvement in mineral grade, i.e., the weight percentage of valuable minerals in the concentrated material as compared to the material prior to the froth flotation process. In embodiments, the use of a selective polysaccharide agent or flocculant results in an increase in the grade of valuable metals of at least about 1%, about 1.5%, about 2%, about 2.5%, about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, or about 10%.

According to various embodiments, the amount of selective flocculation may be quantified. For example, the amount of selective flocculation may be quantified in terms of a percentage improvement in mineral grade, i.e. the weight percentage of valuable minerals in the concentrated material as compared to the material prior to the froth flotation process. In embodiments, the use of a selective flocculant causes an increase in the grade of valuable metals of at least about 1%, about 1.5%, about 2%, about 2.5%, about 3%, about 4%, about 5%, about 6%, about 7%, about 8%, or about 10%. For the recovered metal grade, even a relatively modest amount of improvement may represent a significant increase in the production and profitability of the process over time.

In an embodiment, a method of enriching an iron-containing mineral from an ore having an iron-containing material and a silicate-containing gangue includes performing a selective flocculation step in the presence of one or more dispersants prior to a flotation process. In an embodiment, a method of enriching an iron-containing mineral from an ore having an iron-containing material and a desired mineral or material includes performing a selective flocculation step in the presence of one or more dispersants prior to a flotation process.

In embodiments, one or more dispersants are added at any stage of the process prior to the settling step. In certain embodiments, one or more dispersants are added prior to or simultaneously with the addition of the disclosed selective flocculants.

According to one embodiment, the method produces: a top portion which is a gangue-rich dispersion, such as a silicate-rich dispersion; and a bottom portion that is enriched in the desired mineral or material (underflow), e.g., iron.

According to one embodiment, the method produces: a top portion which is a dispersion comprising the desired mineral or material; and a bottom portion rich in iron or iron-containing material.

According to one embodiment, the method produces: a top portion which is a dispersion rich in the desired mineral; and a bottom fraction, which is rich in gangue and/or other minerals. According to one embodiment, the method produces: a top portion that is a dispersion of an iron-rich or iron-containing material; and a bottom fraction enriched in the desired mineral or material.

According to one embodiment, the selective flocculation process produces: a top portion that is a gangue-rich dispersion, e.g., a silicate-rich dispersion; and a bottom portion, which is enriched in the desired minerals (underflow), e.g., iron.

According to one embodiment, the selective flocculation process produces: a top portion that is a dispersion rich in the desired mineral, e.g., a niobium-rich dispersion; and a bottom portion, which is rich in iron-containing gangue.

According to embodiments, one or more steps may be performed to prepare the ore for flocculation and/or flotation prior to treating the ore with a selective polysaccharide agent or flocculant, or prior to a selective flocculation step. For example, in one step of the process, the ore can be ground with water to a desired particle size to produce a slurry. The grain size of the ore and the degree of mixing with the silica matrix determine the grind size to which the rock must be reduced in order to enable efficient separation, for example by subsequent desliming and froth flotation, to provide a high purity metal concentrate. Exemplary average particle sizes are less than about 1mm, for example in the range of about 1 to about 300 μm, about 5 to 200 μm, about 5 to 150 μm, or about 5 to about 50 μm.

Optionally, a conditioning agent such as sodium hydroxide and/or sodium silicate may be added to the mill prior to grinding the coarse ore. In one embodiment, sufficient water is added to the mill to provide a slurry suitable for subsequent processing, as is well understood in the art, for example, containing from about 50% to about 70% solids, although the amount is understood to be not particularly limited.

In embodiments, an alkali or alkaline pH adjuster may be added to adjust the pH of the slurry. For example, a pH adjusting agent may be added to the slurry to produce a pH in the range of about 6 to about 11, about 8 to about 11, about 9 to about 11, about 10 to about 11, about 8.5 to about 10.5, or about 9.5 to about 10.5. In certain embodiments, the pH may be adjusted to about 8.5, about 9.5, or about 10.5. In embodiments, the pH of the slurry in the flocculation tank is maintained between about 6 to about 11, or about 8 to about 11. In embodiments, the pH may be adjusted to produce optimal iron recovery.

According to embodiments, the selective flocculation process may comprise the step of adding one or more dispersants. For example, the dispersant may be added to the mixture before, after, or during the addition of the one or more selective flocculants and/or any other treatment agent.

In embodiments, the selective flocculation process may include steps that involve conditioning or agitating the mixture. For example, once all of the other treating agents present before or after have been added to the mixture, the mixture may be further conditioned or stirred for a period of time before undergoing the settling step.

In embodiments, the selective flocculation process may be performed in multiple flocculation treatment steps. For example, the selective flocculation process may be carried out in a flocculation unit comprising a plurality of interconnected ponds in series, the first pond typically being used for coarser settling, with subsequent ponds being used for finer settling.

In embodiments, the mineral water slurry comprises from about 20 to about 60 wt%, or from about 30 to about 50 wt% solids prior to beneficiation, flotation, or flocculation treatment. In embodiments, the duration of the selective flocculation process depends on the desired result. In embodiments, the time for the beneficiation, flotation, or flocculation process can be from about 1 to about 10 minutes for each cycle. The time of the beneficiation, flotation, or flocculation process can depend at least in part on the gangue content, the grain size of the ore to be treated, and the number of flocculation tanks involved.

In embodiments, the selective polysaccharide agents or flocculants, compositions and methods may be used to provide higher selectivity and desired mineral recovery when used in a flocculation process compared to other flocculants. In embodiments, the treated or flocculated mineral concentrate obtained by the process (with or without subsequent flotation treatment), such as hematite concentrate, is a refined mineral concentrate meeting steel industry specifications. In embodiments, selective polysaccharide agents or flocculants, compositions and methods may be used to maximize the desired mineral or metal value recovery to increase the yield of metal charge per unit ore feed, which in turn improves production and profitability. In embodiments, selective polysaccharide agents or flocculants, compositions and methods may be used to maximize iron recovery to increase the yield of metal charge per unit ore feed, which in turn improves production and profitability.

In embodiments, the selective polysaccharide agents or flocculants, compositions and methods described herein may be used to upgrade at least about 0.5%, about 1%, about 2%, about 3% or about 5% of a desired mineral or material.

In embodiments, the selective polysaccharide agents or flocculants, compositions and methods described herein may be used to increase the grade of iron from iron ore such that the grade of recovered iron is at least about 55%, about 56%, about 57%, about 58%, about 59%, about 60%, about 61%, or about 63%. In embodiments, the selective polysaccharide agents or flocculants, compositions and methods described herein may be used to upgrade iron from iron ore such that the grade of recovered iron is in the range of about 55% to about 64%, about 56% to about 64%, about 57% to about 64%, or about 58% to about 64%.

In embodiments, the selective polysaccharide agents or flocculants, compositions and methods described herein may be used to upgrade iron from iron ore by at least about 0.5%, about 1%, about 1.5%, about 2%, about 2.5%, about 3%, about 3.5%, about 4%, about 4.5%, about 5%, about 5.5% or about 6%. For example, the selective polysaccharide agents or flocculants, compositions and methods described herein may be used to increase the grade of iron from iron ore from an initial iron grade of about 58% to a grade of at least about 58.5%, about 59%, about 59.5%, about 60%, about 60.5%, about 61%, about 61.5%, about 62%, about 62.5% or about 63%.

In embodiments, the selective polysaccharide agents or flocculants, compositions and methods described herein may be used to upgrade iron from iron ore by about 0.5% to about 7%, about 1% to about 7%, about 1.5% to about 6%, or about 4.5% to about 6%.

In embodiments, the selective polysaccharide agents or flocculants, compositions and methods described herein may be used to increase the grade of iron oxide from iron ore such that the grade of recovered iron oxide is at least about 80%, about 81%, about 82%, about 83%, about 84%, about 85%, about 86%, about 87%, about 88%, about 89%, about 90%, about 91% or about 92%. In embodiments, the selective polysaccharide agents or flocculants, compositions and methods described herein may be used to increase the grade of iron oxide from iron ore such that the grade of recovered iron oxide is in the range of about 81% to about 92%, about 82% to about 90%, or about 82% to about 88%.

In embodiments, the selective polysaccharide reagents or flocculants, compositions and methods described herein may be used to increase the recovery of iron from iron ore to at least about 50%, about 60%, about 62%, about 65%, about 70%, about 75%, about 80%, about 85% or about 90%. In embodiments, the selective polysaccharide reagents or flocculants, compositions and methods described herein may be used to increase the recovery of iron from iron ore such that the recovery of iron is in the range of about 50% to about 100%, about 60% to about 98%, about 70% to about 98%, or about 80% to about 98%.

In embodiments, the polysaccharide agents or flocculants, compositions and methods may be used to reduce the amount of silica in iron ore to less than about 22%, about 21%, about 20%, about 19%, about 18%, about 17%, about 16%, about 15%, about 14%, about 13%, about 12%, about 11%, about 10%, about 9%, about 8%, about 7%, about 6%, about 5%, about 4%, about 3% or about 2%.

The following examples are provided for illustrative purposes only and are not intended to be limiting.

Examples