METHOD FOR DRAINING MINING WASTE

Abstract

The present invention relates to a method for dewatering mine tailings, comprising the addition of at least one water-soluble polymer and at least one surfactant to said tailings.

Description

/ 27 METHOD FOR DRAINING MINING WASTE Technical scope of the invention

[001] This invention relates to a method for draining mining tailings comprising adding at least one water-soluble polymer and at least one surfactant to said tailings. Previous technique

[002] In the mining industry, tailings are the waste generated during ore processing. They are usually stored in retention basins, ponds, dams or dikes in semi-liquid form when they are mining sludges, or in the form of tailings when they are dry or solid materials. These volumes of stored waste represent an environmental and human risk in the event of failure of these structures.

[003] Furthermore, the current development of environmental policies worldwide is increasingly forcing mining companies to restore mining sites, requiring them to treat mining tailings, particularly by draining them in the case of mining sludge, to form stable soil.

[004] Draining these sludges has several advantages for mining companies: - a reduction in the total volume of waste. Furthermore, the discharged water can be recycled for mineral exploration, which is vital nowadays, especially in countries with water scarcity.

[005] - Drained mining sludge is lighter, making it easier to transport and dispose of. This reduces the costs associated with transporting tailings to permanent storage or further processing sites.

[006] - Draining tailings mud helps improve its geotechnical stability. By reducing the water content, the tailings become Petition 870260061745, dated 06 / 24 / 2026, page 12 / 38 / 27 more compact and less likely to liquefy or shift uncontrollably. This reduces the risk of landslides or failure of the storage facility.

[007] Specific drainage techniques for mining sludge can vary according to its characteristics, treatment objectives, and environmental constraints. Methods such as filtration, centrifugation, pressing, or thermal drying can be used, depending on the requirements.

[008] The typical steps in a sludge drainage method by filtration are as follows: - The sludge is usually conditioned by the addition of chemical reagents such as flocculants to promote the agglomeration of particles; The conditioned sludge is then fed into a filtration device for drainage; The device is pressurized, and the solid and liquid materials in the sludge are separated. The solid matter is collected in or on the filter and forms a filter cake; As filtration progresses, the filter cake thickens and solidifies; This cake can be washed to remove any remaining impurities; Once filtration is complete, the filter cake is removed from the filter and discarded as waste.

[009] Each mining sludge has its own specific characteristics and treatment requirements, which can influence the steps and parameters of the filtration process. Filtration techniques can also vary depending on the equipment available and the specific treatment objectives of each mine.

[0010] Document US4210531 describes the combined use of a surfactant and an organic solvent in a sludge previously flocculated with a high molecular weight non-ionic polyacrylamide to reduce the unit Petition 870260061745, dated 06 / 24 / 2026, page 13 / 38 / 27 of the pie.

[0011] US patent document 4968435 describes the synthesis of an inverse emulsion insoluble cationic polymer comprising nonionic surfactants, and the use of this polymer as a flocculant.

[0012] Document WO2006027121 describes a method for mechanically draining hydrocarbon-containing sludge. The sludge is pre-treated with a combination of clay, an inorganic coagulant, preferably cationic flocculation polymers, and a preferably anionic surfactant to improve cake drying.

[0013] Document US2016310964 mentions the combination of expandable clay, an anionic polymer with a low ionic charge and very high molecular weights, with a cationic collector to improve the drainage of oil sands residues after a flotation method.

[0014] US document 2016 / 0311709 describes a process for dewatering oil sands residues.

[0015] US document 2011 / 0009534 describes a process for dehydrating mining waste.

[0016] US patent 2002 / 0190005 describes a process for inverting an emulsion containing a flocculant and the use of this inverted emulsion in the treatment of aqueous sludge.

[0017] Although the methods described offer the possibility of draining mining tailings, mining companies are still facing long treatment times that impact productivity. Industrial filtration tools have a predefined size and capacity, which limits the amount of tailings that can be processed simultaneously. In addition, filtration requires relatively long cycle times to achieve complete filtration.

[0018] In addition to these productivity problems, mining companies need to reduce the residual moisture content of the cakes in order to Petition 870260061745, dated 06 / 24 / 2026, page 14 / 38 / 27 to comply with regulatory restrictions, as in Brazil for example, or to recycle as much water as possible in countries where water scarcity is high, such as in Chile.

[0019] The Applicant has found that the combination of at least one specific polymer and at least one specific surfactant, applied to a mechanical drainage system, makes it possible to improve the drainage rate of mining tailings, whatever their origin, while reducing the amount of residual moisture (thus increasing dryness), thereby allowing compliance with local regulatory restrictions while increasing productivity. In addition to these advantages, the resulting cake is less sticky, which improves the overall efficiency of the method.

[0020] The method described here is in line with the principle of environmental awareness and the impact of industry and humanity on the planet. Reducing the time required to drain mining tailings reduces the amount of greenhouse gases, such as CO2, produced by drainage systems, and reducing the residual moisture present in filter cakes allows water to be recovered more efficiently and recycled in greater quantities.

[0021] Furthermore, the present invention is advantageously implemented using materials of biological origin, for example biomass or recycled materials. The synthesis of the monomers used is advantageously a biological synthesis, for example by enzymatic catalysis. The energy used to implement the dehydration process according to the invention is advantageously derived from a heat pump or a renewable source, for example wind energy, photovoltaic energy, or, in particular for mobile installations, fuel cells or lithium batteries. Description of the invention

[0022] This invention relates to a method for draining mining waste comprising the following steps: Petition 870260061745, dated 06 / 24 / 2026, page 15 / 38 / 27 a) Add and mix at least one water-soluble polymer and at least one surfactant to the mining residue to obtain a conditioned mining residue; b) Drain the conditioned mining residue by mechanical filtration to obtain a drained mining residue; the water-soluble polymer(s) being selected from: - Water-soluble anionic polymers with a molecular weight between 800,000 and 3,000,000 g / mol; - Water-soluble cationic polymers with a molecular weight between 10,000 and 3,000,000 g / mol; - and mixtures thereof

[0023] The surfactant(s) being chosen from: - anionic surfactants, and / or; - non-ionic surfactants; and - mixtures of the same. Description of the invention

[0024] By “mechanical filtration” we mean filtration performed using mechanical energy.

[0025] “Polymer” refers to a homopolymer or a copolymer. A copolymer is a polymer obtained from at least two different monomers.

[0026] By “hydrophilic monomer” is meant a monomer having an octanol / water partition coefficient, Kow, less than or equal to 1, wherein the Kow partition coefficient is determined at 25°C in an octanol / water mixture having a volume ratio of 1 / 1, at a pH between 6 and 8.

[0027] By “hydrophobic monomer” is meant a monomer having an octanol / water partition coefficient, Kow, greater than 1, wherein the Kow partition coefficient is determined at 25°C in a mixture of Petition 870260061745, dated 06 / 24 / 2026, page 16 / 38 6 / 27 octanol / water having a volume ratio of 1 / 1, at a pH between 6 and 8.

[0028] The octanol / water partition coefficient, Kow, represents the ratio of concentrations (g / L) of a monomer between the octanol phase and the aqueous phase. It is defined as follows: [monomedium 1 , , J octunol ^OW ~ f ' Ί l jagua

[0029] By “water-soluble polymer” we mean a polymer that gives an aqueous solution without insoluble particles when dissolved with stirring at 25°C and a concentration of 10 gL·1 in deionized water.

[0030] By “anionic polymer” we mean a polymer consisting of hydrophilic anionic monomer(s) and optionally non-ionic hydrophilic monomer(s).

[0031] By “cationic polymer” we mean a polymer consisting of hydrophilic cationic monomer(s) and optionally non-ionic hydrophilic monomer(s).

[0032] By “X and / or Y” we mean “X” or “Y”, or “X and Y”.

[0033] The invention also covers all possible combinations other than those described, whether preferred or given by way of example. Furthermore, when value ranges are indicated, the terminals are part of these ranges. The description also includes all combinations within the limits of these value ranges. For example, the value ranges “1 to 20, preferably 5 to 15” imply descriptions of the ranges “1 to 5”, “1 to 15”, “5 to 20” and “15 to 20” and the values ​​1, 5, 15 and 20.

[0034] Molecular weight is determined by the intrinsic viscosity of polymers. Intrinsic viscosity can be measured by methods known to a person skilled in the art, and can be calculated from viscosity values ​​reduced by other polymer concentrations. Petition 870260061745, dated 06 / 24 / 2026, page 17 / 38 / 27, proposes a graphical method consisting of plotting reduced viscosity values ​​(y-axis) against concentration (x-axis) and extrapolating the curve to zero concentration. The intrinsic viscosity value is plotted on the y-axis or using the least squares method. The molecular weight can then be determined using the Mark-Houwink equation: [η] = K.Ma

[0035] [η] represents the intrinsic viscosity of the polymer as determined by the solution viscosity method.

[0036] K is an empirical constant.

[0037] M represents the molecular weight of the polymer.

[0038] α represents the Mark-Houwink coefficient.

[0039] K and α depend on the particular polymer-solvent system. Dehydration method Mining waste

[0040] Mining residue used in the context of the invention includes any type of residue or waste from mineral exploration, such as coal mines, diamond mines, phosphate mines, metal mines (alumina, platinum, iron, gold, copper, silver, etc.). Suspensions may also be derived from drilling muds. Residues from oil sands operations are excluded from the scope of the invention. Waste conditioning stage

[0041] Before filtration, the residue undergoes a conditioning step to improve the filtration method.

[0042] This conditioning is achieved by adding simultaneously or separately at least one water-soluble polymer and at least one surfactant to the residue.

[0043] The water-soluble polymer and surfactant can be added all at once or in several stages. Preferably, they are added all at once.

[0044] They are usually added in solution form. Petition 870260061745, dated 06 / 24 / 2026, page 18 / 38 / 27

[0045] The water-soluble polymer and surfactant can be added successively (for example, the polymer is added first, then the surfactant, or vice versa), in parallel or alternately (a first fraction of one, followed by a first fraction of the other, then a second fraction of the first, and so on).

[0046] Preferably, they are added in succession, most preferably the polymer is added first, followed by the surfactant.

[0047] The water-soluble polymer and the surfactant can be added at the same injection point, or they can be added at different injection points, preferably at the same injection point.

[0048] The amount of water-soluble polymer added to the mining residue is advantageously between 0.5 and 5,000 ppm based on the dry weight of the mining residue to be drained, preferably between 1 and 2,000 ppm, more preferably between 2 and 1,000 ppm, more preferably between 3 and 500 ppm, more preferably between 5 and 200 ppm and more preferably between 10 and 100 ppm.

[0049] The amount of surfactant added to the mining residue is advantageously between 10 and 10,000 ppm based on the dry weight of the mining residue to be drained, preferably between 50 and 5,000 ppm, more preferably between 200 and 2,000 ppm. Water-soluble polymer

[0050] The water-soluble polymer according to the invention is selected from: - Water-soluble anionic polymers with a molecular weight between 800,000 and 3,000,000 g / mol; - Water-soluble cationic polymers with a molecular weight between 10,000 and 3,000,000 g / mol.

[0051] Advantageously, anionic hydrophilic monomers are chosen from among monomers having vinyl functions (advantageously Petition 870260061745, dated 06 / 24 / 2026, page 19 / 38 / 27 acrylic, maleic, fumaric, malonic, itaconic or allyl). They may contain a carboxylate, phosphonate, phosphate, sulfate, sulfonate or other anionically charged group.Examples of suitable monomers include acrylic acid; methacrylic acid; dimethylacrylic acid; itaconic acid; itaconic acid hemiester; itaconic anhydride; itaconamide; crotonic acid; maleic acid; fumaric acid; acrylamido undecanoic acid; 3-acrylamido 3-methylbutanoic acid; maleic anhydride; Strong acid monomers with, for example, a sulfonic acid or phosphonic acid function, such as vinylsulfonic acid, vinylphosphonic acid, allylsulfonic acid, metalylsulfonic acid, 2-methylidenepropane-1,3-disulfonic acid, 2-sulfoethyl methacrylate, sulfopropyl methacrylate, sulfopropyl acrylate, allylphosphonic acid, styrene sulfonic acid, 2-acrylamido-2-methylpropanesulfonic acid (ATBS), 2-acrylamido-2-methylpropanedisulfonic acid; water-soluble salts of these monomers, such as alkali metal, alkaline earth metal or ammonium salts; and mixtures thereof.Preferably, the anionic hydrophilic monomer is acrylic acid, one of its salts, and mixtures thereof.

[0052] The amount of anionic hydrophilic monomers in the water-soluble anionic polymer is advantageously between 5 and 100 mol% relative to the total amount of monomer in the water-soluble anionic polymer, preferably between 10 and 50 mol%, more preferably between 15 and 35 mol%, the remaining amount of monomer to reach 100 mol% being non-ionic hydrophilic monomers.

[0053] In a particular embodiment, the hydrophilic anionic monomer(s) may be partially or completely salified.

[0054] By saltified, we mean the substitution of a proton of at least one acidic function of the type -R(=O)-OH (with R = P, S, or C) of the anionic monomer by a metal or ammonium cation to form a salt of the type -R(=O)-OX (X being a metal or ammonium cation). In other words, the Petition 870260061745, dated 06 / 24 / 2026, page 20 / 38 / 27 The non-salified form corresponds to the acidic form of the monomer, for example, RC(=O)-OH in the case of the carboxylic acid function, while the salified form of the monomer corresponds to the form RC(=O)-O-X+, X+ corresponding to an alkaline or ammonium cation. The acidic functions of the water-soluble polymer can be partially or completely salified.

[0055] The salified form advantageously corresponds to salts of alkali metals (Li, Na, K...), alkaline earth metals (Ca, Mg...) or ammonium (for example, ammonium ion or tertiary ammonium). The preferred salts are sodium salts.

[0056] Salification can be performed before, during, or after polymerization.

[0057] In a particular embodiment, the polymer advantageously comprises between 1 and 100 mol percent of hydrophilic anionic monomer(s) in salified form, preferably between 50 and 100 mol percent.

[0058] Advantageously, the hydrophilic cationic monomer(s) is / are chosen from monomers derived from vinyl-type units (advantageously acrylamide, acrylic, allylic or maleic), these monomers having a phosphonium or quaternary ammonium function. In particular, and without limitation, diallyldialkyl ammonium salts such as diallyl dimethyl ammonium chloride (DADMAC); acidified or quaternized salts of dialkylaminoalkylacrylamides; Acidified or quaternized salts of dialkylaminoalkylmethacrylamides, for example, methacrylamidopropyl trimethyl ammonium chloride (MAPTAC), acrylamidopropyl trimethyl ammonium chloride (APTAC), acidified or quaternized salts of dialkylaminoalkyl acrylate, such as quaternized or salified dimethylaminoethyl acrylate (ADAME), acidified or quaternized salts of dialkylaminoalkyl methacrylate, such as quaternized or salified dimethylaminoethyl methacrylate (MADAME), and mixtures thereof. Advantageously, the Petition 870260061745, dated 06 / 24 / 2026, page 21 / 38 / 27 alkyl groups are C1-C3. Preferably, the hydrophilic cationic monomer is diallyl dimethyl ammonium chloride.

[0059] A person skilled in the art will know how to prepare quaternized monomers, for example using a quaternizing agent of the type RX, wherein R is an alkyl group and X is a halogen or sulfate. The quaternizing agent may be chosen from dialkyl sulfates containing 1 to 6 carbon atoms or alkyl halides containing 1 to 6 carbon atoms. Preferably, the quaternizing agent is chosen from methyl chloride, benzyl chloride, dimethyl sulfate or diethyl sulfate. In addition, this invention also encompasses DADMAC, APTAC and MAPTAC monomers whose counter-ion is a sulfate, fluoride, bromide or iodide instead of chloride.

[0060] “Quaternizing agent” refers to a molecule capable of alkylating a tertiary amine.

[0061] The amount of hydrophilic cationic monomers in the water-soluble cationic polymer is advantageously between 5 and 100 mol% relative to the total amount of monomer in the water-soluble cationic polymer, preferably between 50 and 100 mol%, more preferably between 80 and 100 mol%, the remaining amount of monomer to reach 100 mol% being non-ionic hydrophilic monomers.

[0062] Alternatively, the water-soluble cationic polymer may be a polyamine obtained by condensation between epichlorohydrin and dimethylamine.

[0063] The term 'amine' encompasses both the neutral form and the ionic form (i.e., in the ammonium form).

[0064] Water-soluble anionic polymers and water-soluble cationic polymers may optionally comprise at least one non-ionic hydrophilic monomer. Petition 870260061745, dated 06 / 24 / 2026, page 22 / 38 / 27

[0065] Advantageously, the non-ionic hydrophilic monomer(s) is / are selected, in particular, from the group comprising water-soluble vinyl monomers, such as acrylamide, methacrylamide, N-alkylacrylamides, N-alkylmethacrylamides, N,N-dialkylacrylamides (for example, N,N-dimethylacrylamide or N,N-diethylacrylamide), N,N-dialkylmethacrylamides, alkoxylated esters of acrylic acid, alkoxylated esters of methacrylic acid, N-vinylpyrrolidone, N-methyloacrylamide, N-vinylformamide (NVF), N-vinylacetamide, N-vinylimidazole, N-vinylsuccinimide, acryloylmorpholine (ACMO), acryloyl chloride, glycidyl methacrylate, methacrylate of Glyceryl, diacetone acrylamide, hydroxyalkyl (meth)acrylate, thioalkyl (meth)acrylate, hydroxyalkylacrylates, hydroxyalkyl methacrylates, and mixtures thereof. Among these nonionic monomers, the alkyl groups are advantageously C1-C5, more advantageously C1-C3. Linear alkyl groups are preferred.Preferably, the non-ionic hydrophilic monomer is acrylamide.

[0066] The water-soluble polymer can be partially or completely post-hydrolyzed.

[0067] The water-soluble polymer can be post-hydrolyzed. Post-hydrolysis is the reaction of the polymer after polymerization. This step consists of the reaction of hydrolyzable functional groups of advantageously non-ionic monomers, most advantageously amide or ester functions, with a hydrolyzing agent. This hydrolyzing agent can be an enzyme, an ion-exchange resin, or an alkaline base. Preferably, the hydrolyzing agent is a Bronsted base. During this post-hydrolysis stage of the water-soluble polymer, carboxylic acid or amine functions are formed. In fact, the reaction between the base and the amide or ester function present in the water-soluble polymer produces amine or carboxylate groups, respectively.

[0068] In a particular embodiment, the water-soluble polymer may comprise a transfer agent. Petition 870260061745, dated 06 / 24 / 2026, page 23 / 38 / 27

[0069] The transfer agent is advantageously selected from methanol, isopropyl alcohol, sodium, calcium, potassium, magnesium or ammonium hypophosphite; 2-mercaptoethanol; 3-mercaptopropanol; dithiopropylene glycol; thioglycerol; thioglycolic acid; thiohydracrylic acid; thiolactic acid; thiomalic acid; cysteine; and aminoethanethiol; thioglycolic acid; thiohydracrylic acid; thiolactic acid; thiomalic acid; cysteine; and aminoethanethiol; dodecyl mercaptan; sodium, calcium, magnesium, potassium or ammonium metalisulfonate; and mixtures thereof. Preferably sodium hypophosphite.

[0070] The amount of transfer agent in the polymer is advantageously between 0 and 50,000 ppm by weight relative to the total weight of polymer monomers, preferably between 1 and 10,000 ppm by weight, more preferably between 5 and 5,000 ppm by weight, even more preferably between 20 and 2,000 ppm by weight. When present, the transfer agent represents at least 10 ppm by weight relative to the total weight of polymer monomers, preferably at least 20 ppm by weight.

[0071] In a particular embodiment, the polymer does not comprise a transfer agent.

[0072] In a particular mode, the polymer can be structured by at least one branching agent. A structured polymer refers to a non-linear polymer that has side chains.

[0073] The branching agent is advantageously chosen from: - Structuring agents, which may be chosen from the group comprising unsaturated polyethylene compounds (having at least two unsaturated functions, with the exception of diallyldialkyl ammonium), such as vinyl functions, in particular allylic or acrylic functions. Examples include methylene bis-acrylamide (MBA), triallylamine, tetraallylammonium chloride or 1,2-dihydroxyethylene bis-(N-acrylamide), - compounds having at least two epoxy functional groups, - compounds having at least one unsaturated functional group and one Petition 870260061745, dated 06 / 24 / 2026, page 24 / 38 / 27 epoxy function, - macroinitiators such as polyperoxides, polyazo compounds and polytransfer agents such as polymercaptans and polyols, - functionalized polysaccharides, - water-soluble metal complexes composed of: * a metal with a valence greater than 3, such as, for example but not limited to, aluminum, boron, zirconium or titanium, and * a ligand carrying a hydroxyl function.

[0074] When the water-soluble polymer comprises at least one branching agent, it remains water-soluble. Those skilled in the art will know how to adjust the amount of branching agent, and possibly the amount of transfer agent, in order to achieve the desired result.

[0075] The polymers used in the method of the invention are advantageously linear, that is, the polymers do not include a branching agent.

[0076] The polymer can be obtained by solution polymerization; gel polymerization; precipitation polymerization; suspension polymerization; reactive extrusion polymerization; water-in-water polymerization; or micellar polymerization, preferably the polymer is prepared by polymerization in aqueous solution.

[0077] In the context of the invention, the polymer is not obtained by reverse emulsion.

[0078] In the context of the invention, no surfactant or oil is added during the polymerization of the polymer of the invention.

[0079] In fact, it has been observed that the presence of oil or surfactant during the preparation of the polymer leads to a loss of application performance when used in combination with the surfactant of the invention. Petition 870260061745, dated 06 / 24 / 2026, page 25 / 38 / 27

[0080] Polymerization is radical polymerization. By radical polymerization, we mean free radical polymerization using UV, azo, redox or thermal initiators, as well as controlled radical polymerization (PCR) or matrix polymerization techniques.

[0081] Controlled radical polymerization techniques include, but are not limited to, Iodine Transfer Polymerization (ITP), Nitroxide Mediated Polymerization (NMP), Atom Transfer Radical Polymerization (ATRP), Addition-Fragmentation Reversible Chain Transfer Polymerization (RAFT), including MADIX (MAcromolecular Design by Interchange of Xanthates) technology, various variations of polymerization with organometallic compounds (“Organometallic Mediated Radical Polymerization” (OMRP)), and controlled radical polymerization with heteroatom compounds (“OrganoHeteroatom Mediated Radical Polymerization” (OHRP)).

[0082] The polymer may be in liquid, gel or solid form when its preparation includes a drying step such as spray drying, drum drying, radiation drying such as microwave drying or fluidized bed drying.

[0083] The water-soluble anionic polymer advantageously has a weighted average molecular weight between 1,000,000 and 2,500,000 g / mol, preferably between 1,500,000 and 2,000,000 g / mol.

[0084] The water-soluble cationic polymer advantageously has a weighted average molecular weight between 20,000 and 2,000,000 g / mol, preferably between 30,000 and 1,500,000 g / mol, more preferably between 50,000 and 1,000,000 g / mol, most preferably between 100,000 and 800,000 g / mol.

[0085] In a preferred embodiment, the water-soluble polymer is cationic.

[0086] In a particular preferred embodiment, the cationic polymer Petition 870260061745, dated 06 / 24 / 2026, page 26 / 38 / 27, soluble in water, is a polyamine obtained by the condensation between epichlorohydrin and dimethylamine, having a molecular weight between 10,000 and 800,000 g / mol. Surfactant

[0087] The surfactant according to the invention is chosen from: * anionic surfactants, and / or; * non-ionic surfactants.

[0088] The surfactant advantageously has an HLB between 5 and 17, preferably between 7 and 15, more preferably between 8 and 12.

[0089] The hydrophilic-lipophilic balance (HLB) of a chemical compound is a measure of its hydrophilic and / or lipophilic properties, determined by calculating values ​​for other regions of the molecule, as described by Griffin in 1949.

[0090] In this invention, we adopt Griffin's method based on calculating a value based on the chemical groups of the molecule. Griffin assigned a dimensionless number between 0 and 20 to give information about water and oil solubility.

[0091] The HLB value of a substance with total molecular mass M and a hydrophilic part with molecular mass Mh is given by: HLB = 20 (Mh / M).

[0092] The anionic surfactant(s) is / are advantageously selected from the group consisting of salts of alkyl sulfates, alkyl sulfonates, alkyl aryl sulfonates, alkyl ether sulfates, alpha olefin sulfonates, alkyl aryl ether sulfates, sulfated alcohols and ethoxylated sulfated alcohols, taurates, petroleum sulfonates, alkyl naphthalene sulfonates, alkyl sarcosinates and alkyl sulfosuccinates in which the alkyl group contains from 8 to 22 carbon atoms and the aryl group is phenyl or naphthyl, and mixtures thereof. Preferably sodium alkyl sulfosuccinate, more preferably sodium dioctyl sulfosuccinate. Petition 870260061745, dated 06 / 24 / 2026, p. 27 / 38 / 27

[0093] The non-ionic surfactant(s) is / are advantageously selected from ethylene glycol monostearate, propylene glycol myristate, glyceryl monostearate, glyceryl stearate, polyglyceryl-4-oleate, sorbitan acylate, sucrose acylate, PEG-150 laurate, PEG-400 monolaurate, polyoxyethylene monolaurate. Polysorbates, polyoxyethylene octylphenyl ether, PEG-1000 cetyl ether, polyoxyethylene tridecyl ether, polypropylene glycol butyl ether, Poloxamer® 401, stearoyl monoisopropanolamide, hydrogenated polyoxyethylene tallowamide, secondary alcohol ethoxylates, decyl glucoside, lauryl glucoside, octyl glucoside, fatty alcohol polyglycol ether, alkylphenol polyglycol ether, fatty acid polyglycol ester, mixed polymers of polypropylene oxide and polyethylene oxide, N-methyl myristamide.N-sorbityl lauramide, N-methyl myristamide, N-sorbityl myristamide and alkyl polysaccharides such as octyl, nonyldecyl, undecyldodecyl, tridecyl, tetradecyl, pentadecyl, hexadecyl, pentadecyl, pentadecyl and pentadecyl. pentadecyl, hexadecyl, heptadecyl and octadecyl. di-, tri-, tetra-, penta- and hexaglycosides, galactosides, lactosides, glucoses, fructosides, fructoses and / or galactoses, and mixtures thereof.

[0094] Surfactant formulations may contain additional components such as alkali metal salts (such as NaCl, NaOH), alkaline earth metal salts (such as MgCl2, CaCl2) and oxidants (such as hydrogen peroxide). The relative amounts of the additional components that make up the surfactant formulation may vary over a wide range. Dehydration stage by mechanical filtration

[0095] The conditioned waste is then fed into a filtration device to drain, separating the solid waste from the liquid waste.

[0096] Filtration is carried out under pressure.

[0097] Preferably, the applied pressure varies from 100 to 1500 kPa (1 Petition 870260061745, dated 06 / 24 / 2026, pp. 28 / 38 / 27 to 15 bar).

[0098] Preferably, the pressure is gradually increased during filtration, for example by 100 kPa (1 bar) / min until a pressure of at least 1500 kPa (15 bar) is reached.

[0099] Filtration is typically carried out over a period ranging from 1 to 300 minutes, preferably from 5 to 200 minutes, more preferably from 10 to 100 minutes.

[00100] Solid waste is typically collected in the filter and forms the filter cake.

[00101] The liquids are collected in a separate collector and form the filtrate.

[00102] The mechanical filtration device is a type of equipment used to drain mining waste by applying mechanical energy under pressure. Advantageously, the mechanical filtration device is chosen from filter presses, belt filters. Preferably, it is a filter press.

[00103] The dry matter content in the drained mining residue is advantageously at least 80%, preferably at least 81%, more preferably at least 82%, more preferably at least 83%, more preferably at least 84% and most preferably at least 85%.

[00104] In a preferred embodiment, at the end of the dehydration stage, the cake is subjected to post-treatment.

[00105] Post-treatment consists of washing and / or drying the cake.

[00106] Drying can be carried out using air, for example under an air current (especially compressed air) or in an oven.

[00107] Washing the cake recovers valuable dissolved elements or eliminates impurities and / or toxic products used during ore extraction (caustic soda, cyanide, etc.), thus reducing hazard and pollution. Petition 870260061745, dated 06 / 24 / 2026, pages 29 / 38 / 27 of the rejections.

[00108] Air drying of the cake increases dryness (dry matter content).

[00109] The characteristics of these treatments can be adjusted by a person skilled in the art according to the final objectives to be achieved for the discharge of solid waste into nature.

[00110] The invention and its advantages will be better illustrated, but not limited to, by the following examples. Examples List of abbreviations:

[00111] DADMAC: Diallyl dimethylammonium chloride (hydrophilic cationic monomer) AMD: Acrylamide (hydrophilic non-ionic monomer) AA: Acrylic acid (hydrophilic anionic monomer) DMAEA.Q: Dimethylaminoethyl acrylate methyl chloride APTAC: Acrylamidopropyl trimethyl ammonium chloride Example 1: Sludge drainage in a filter press

[00112] The tests were carried out in a filter press using a single-plate filtration cell manufactured by Choquenet Company (France). The size of the cell used for the tests was 30 mm.

[00113] The test procedure is as follows: 300 g of mud are stirred in a beaker, - The sludge is conditioned by the addition of a polymer and / or surfactant solution (5 g / L); in the case of the invention, the polymer solution is added first, followed by the addition of the surfactant solution; The conditioned sludge is fed into the Choquenet cell's feeding chamber, then injected into the cell under atmospheric pressure. The pressure is increased by 100 kPa (1 bar) / min until a Petition 870260061745, dated 06 / 24 / 2026, p. 30 / 38 / 27 pressure of 800 kPa (8 bar) is reached; The filtration rate is measured by monitoring the volume of filtrate recovered over time using a graduated cylinder.

[00114] - The test is terminated when the volume of recovered filtrate no longer increases. The time taken to reach this plateau corresponds to the cycle time.

[00115] - The filter cake is then recovered, weighed and dried. Once this time has elapsed, the dried cake is reweighed, the ratio of mass before / after drying (oven or air) corresponding to the dryness of the cake. The cake is dried in an oven at 90°C for 12 h (residues I1 to I6) or by passing compressed air through the cake (residues I7 and I8).

[00116] The stickiness of the cake is visually assessed by looking at the appearance of the filter after the cake has been removed from the mold. A score of 1 to 10 is given according to the degree to which the filter is covered by the tested slurry. For a score of 1, the cake comes off easily and no residue is observed on the filter. On the other hand, for a score of 10, the cake comes off with difficulty and the filter is completely covered with a thin film of cake. Finally, the given rating corresponds to a percentage of filter coverage.

[00117] The polymers (P1 to P12) tested are commercial products sold by SNF, and their composition is summarized in Table 1 below. Polymer Polymerization Method Monomer / Polymer Ratio (% mol) Polymer Molecular Weight (g / mol) Filtration Method P1 Gel polymerization AMD / AA (70 / 30) (anionic polymer) 2,000,000 Filter press P2 Solution polymerization DADMAC (100) (cationic polymer) 600,000 Filter press P3 Solution polymerization AMD / AA (70 / 30) (anionic polymer) 600,000 Filter press P4 Gel polymerization AMD / AA (70 / 30) (anionic polymer) 3,200,000 Filter press P5 Solution polymerization Polyamine (cationic) 5,000 Filter press Petition 870260061745, dated 06 / 24 / 2026, page 31 / 38 / 27 P6 Gel polymerization DADMAC (100) (cationic polymer) 3,200,000 Filter press P7 Solution polymerization Polyamine (cationic) 200,000 Filter press P8 Gel polymerization AMD / ATBS (85 / 15) (anionic polymer) 2,000,000 Filter press P9 Gel polymerization AMD / ATBS (85 / 15) (anionic polymer) 3,200,000 Filter press P10 Gel polymerization AMD / ATBS (85 / 15) (anionic polymer) 200,000 Filter press P11 Gel polymerization AMD / ADAME.Q (20 / 80) (cationic polymer) 2,000,000 Filter press P12 Gel polymerization AMD / APTAC (40 / 60) (cationic polymer) 100,000 Filter press Table 1: List of polymers used in the method according to the invention

[00118] The conditioned residues (I1 to I15) according to the invention (i.e., sludge + polymer + surfactant) and the conditioned residues The counterexamples (CE1 to CE12) are shown in Table 2. Conditioned residues Polymer Surfactant CE1 - - CE2 P1 - CE3 P2 - CE4 - Sodium dioctyl sulfosuccinate (anionic) CE5 - Tridecyclic alcohol ethoxylate (C13-Oxo Alcohol,3 exotylate) (non-ionic) CE6 P3 Sodium dioctyl sulfosuccinate (anionic) CE7 P4 Sodium dioctyl sulfosuccinate (anionic) CE8 P1 Cetyltrimethylammonium bromide (cationic) CE9 P5 Tridecyclic alcohol ethoxylate (non-ionic) CE10 P6 Tridecyclic alcohol ethoxylate (non-ionic) CE11 P2 Cetyltrimethylammonium bromide (cationic) CE12 P7 Cetyltrimethylammonium bromide (cationic) I1 P1 Sodium dioctyl sulfosuccinate (anionic) I2 P1 Tridecyclic alcohol ethoxylate (non-ionic) I3 P2 Tridecyclic alcohol ethoxylate (non-ionic) I4 P2 Sodium dioctyl sulfosuccinate (anionic) I5 P7 Sodium dioctyl sulfosuccinate (anionic) I6 P7 Tridecyclic alcohol ethoxylate (non-ionic) I7 P2 Sodium dioctyl sulfosuccinate (anionic) I8 P1 Sodium dioctyl sulfosuccinate (anionic) I9 P11 Sodium dioctyl sulfosuccinate (anionic) Petition 870260061745, dated 06 / 24 / 2026, pages 32 / 38 / 27 I10 P12 Sodium dioctyl sulfosuccinate (anionic) I11 P2 Tridecyclic alcohol ethoxylate (6 EO) (non-ionic) I12 P2 C12-C14 alcohol ethoxylate (7EO) (non-ionic) I13 P2 C12-C14 alcohol ethoxylate (2EO) (non-ionic) I14 P2 Sodium tributyl phenolic ether sulfate (anionic) I15 P2 C10-C12 tallow alkyl ethoxylate (25 EO) (non-ionic) Table 2: Polymer + surfactant system compositions for packaged waste according to inventions I1 to I15 and counterexamples CE1 to CE12.

[00119] The filtration and drainage performances between the conditioned wastes according to the invention (I1 to I15) and the comparative conditioned wastes (CE1 to CE12) are shown in Table 3 below. Conditioned Residues Polymer / Surfactant Dosage (ppm) Filtration Duration (min) Filtration Rate (mL / min) % Cake Dryness Cake Stickiness CE1 0 9.2 13.0 82.1 5 CE2 25 / 0 6.9 16.8 81.5 9 CE3 100 / 0 8.0 14.5 81.1 8 CE4 0 / 1000 11.4 11.0 83.3 3 CE5 0 / 1000 12.0 10.5 83.1 2 CE6 25 / 1000 10.2 12.1 83.2 7 CE7 25 / 1000 6.5 16.2 82.5 4 CE8 25 / 1000 6.9 16.1 81.5 10 CE9 100 / 1000 12.0 10.5 83.1 5 CE10 100 / 1000 7.2 13.5 82.1 8 CE11 100 / 1000 7.5 14.7 81.8 9 CE12 100 / 1000 9.0 13.7 81.5 9 I1 25 / 1000 7.0 16.0 84.2 3 I2 25 / 1000 7.3 15.6 84.0 2 I3 100 / 1000 7.8 15.2 85.1 3 I4 100 / 1000 7.5 14.7 85.0 4 I5 100 / 1000 8.0 15.2 84.9 3 I6 100 / 1000 8.1 14.7 84.7 4 I7 100 / 1000 8.0 15.5 86.2 2 Petition 870260061745, dated 06 / 24 / 2026, pp. 33 / 38 / 27 I8 25 / 1000 7.0 16.0 85.1 2 I9 100 / 1000 6.9 16.2 83.8 5 I10 100 / 1000 8.3 15.0 84.3 3 I11 100 / 1000 8.0 14.8 84.0 5 I12 100 / 1000 8.5 14.1 83.7 5 I13 100 / 1000 7.8 15.1 84.7 3 I14 100 / 1000 8.5 14.3 84 5 I15 100 / 1000 8.3 14.9 83.9 5 Table 3: Filtration and drainage performance of conditioned waste according to the invention (I1 to I15) and comparative conditioned waste (CE1 to CE12)

[00120] Cationic or anionic polymers alone (CE2 and CE3) increased the filtration rate at the expense of drying out the cake, resulting in a stickier cake.

[00121] Conversely, the use of surfactant alone (CE4 and CE5) reduces cake moisture at the cost of cycle time, and also reduces cake stickiness.

[00122] The polymer and surfactant combination system according to the invention (I1 to I15) reduces the cycle time and stickiness of the resulting filter cake, and also synergistically improves its dryness. The choice of the best treatment depends on expectations, whether in terms of residual moisture content or filtration rate.

[00123] Tests have shown that this performance is dependent on the molecular weight of the polymer and the nature of the surfactant, both of which must be correctly selected. The selection of molecular weight depends on the overall charge of the polymer, since an anionic polymer has a wider and higher operating range than a cationic polymer.

[00124] Different types of filters were then tested to demonstrate the superior performance achieved using mechanical filters in combination with the mixture compared to other filters, such as vacuum filters. Petition 870260061745, dated 06 / 24 / 2026, pp. 34 / 38 / 27

[00125] The polymer / surfactant mixtures evaluated were mixtures CE1, I3 and I4, the composition of which is detailed in Table 2. Example 2: Evaluation of mechanical and non-mechanical filters in terms of sludge drainage performance. Example 2a: Sludge drainage over a belt filter press (mechanical filter)

[00126] The tests were carried out by draining over a filter fitted with a belt filter press.

[00127] 300 g of mud, previously conditioned with the predefined dose of polymer and surfactant, were placed in the center of the filter.

[00128] A second filter was placed on top with a piece of absorbent paper to absorb the water absorbed by the absorbent paper on top.

[00129] An inflatable cushion connected to the top of the cell allows pressure to be applied gradually in increments of 100 kPa (1 bar) up to 500 kPa (5 bars).

[00130] Each increase in pressure is performed after the flow of pressurized filtrate has completely stopped. The filtration time is obtained by summing together the flow times for each step.

[00131] The resulting cake is then removed from the mold and dried. Its dryness is measured as described in Example 1. Example 2b: Drainage over a vacuum belt filter (non-mechanical filtration)

[00132] The tests were carried out using a Büchner filter covered with a vacuum belt filter cloth equipped with a vacuum pump.

[00133] 300 g of sludge, previously conditioned with the predefined dose of polymer and surfactant, were spread uniformly over the surface of the filter. Petition 870260061745, dated 06 / 24 / 2026, pages 35 / 38 / 27

[00134] Once the addition was complete, the vacuum pump was immediately started to achieve a vacuum of 10 kPa (100 mbar).

[00135] The filtration rate is measured by monitoring the volume of filtrate recovered over time using a graduated test tube.

[00136] Vacuum is applied until cracks appear on the surface of the cake. The duration for which the vacuum is applied corresponds to the filtration time.

[00137] The resulting cake is then removed from the mold and dried. Its dryness is measured as described in Example 1. Example 2c: Sludge drainage using a drum or disc filter (non-mechanical filter)

[00138] The tests were performed on the same device, since disc and drum filters operate on a similar principle.

[00139] The tests were carried out using a filter developed by SNF, which consists of a vertical disc with a diameter of 300 mm connected to a vacuum pump. The disc is covered with a filter cloth similar to that used in disc or drum filters.

[00140] The disc is immersed in a beaker containing 300 g of mud previously conditioned with a predefined dose of polymer and surfactant.

[00141] A vacuum of 300 mbar is then applied. A filter cake forms on the surface of the disc. Filtration is complete when the thickness of the cake no longer varies. The filtration time corresponds to the time between the application of the vacuum and the end of filtration.

[00142] The filtration rate is measured by monitoring the volume of filtrate recovered over time using a graduated test tube.

[00143] The resulting cake is then removed from the mold and dried. Its dryness is measured as described in Example 1. Results Petition 870260061745, dated 06 / 24 / 2026, pages 36 / 38 / 27

[00144] The dryness results obtained for the different compositions according to the filter used are presented in Table 4 below.___________ Conditioned Waste Filter press (INV) Belt filter (INV) Vacuum filter (CE) Disc or drum filter (CE) % dryness gain % dryness gain % dryness gain % dryness gain CE1 82.1 - 81.5 - 79.8 - 79.5 I4 86.2 5.0% 84.6 3.8% 81.8 2.5% 81.4 2.4% I3 85.1 3.6% 83.9 2.9% 81.7 2.4% 81.3 2.2% Table 4: Dryness evaluation according to the type of filter used in a sludge drainage process; INV = invention; CE = counterexample

[00145] The results show, on the one hand, that the compositions according to the invention (polymer + surfactant) make it possible to obtain a cake with a higher dryness (CE1 vs. I3 / I4) regardless of the type of filter used, i.e., mechanical or non-mechanical. On the other hand, the use of mechanical filters also improves the drainage of residues compared to the use of non-mechanical filters.

[00146] The filtration rate is also evaluated according to the composition and filter used to drain the sludge. 00147]_______The results are presented in Table 5 below. Conditioned Waste Filter Press (INV) Belt Filter (INV) Vacuum Filter (CE) Disc or Drum Filter (CE) Filtration Rate (mL / min) Gain Filtration Rate (mL / min) Gain Filtration Rate (mL / min) Gain Filtration Rate (mL / min) Gain CE1 13.0 - 11.9 - 14.2 - 10.7 - I4 15.5 19.2% 13.4 12.6% 15.5 9.2% 11.7 9.3% I3 15.2 16.9% 13.3 11.8% 15.1 6.0% 12.1 11.6% Table 5: Performance of different filter types on filtration speed; INV = invention; CE = counterexample.

[00148] The results show, on the one hand, that the compositions according to the invention (polymer + surfactant) increase the filtration rate (CE1 vs. I3 / I4) regardless of the type of filter used, i.e., mechanical or non-mechanical. On the other hand, the use of mechanical filters Petition 870260061745, dated 06 / 24 / 2026, pp. 37 / 38 / 27 also improves waste dehydration.

[00149] In summary, the present invention improves dryness (dry matter content in the cake), but also the filtration speed, particularly by means of a mechanical filter such as a filter press or belt filter press. Petition 870260061745, dated 06 / 24 / 2026, p. 38 / 38

Claims

1 / 4 CLAIMS 1. A method for draining a mining residue, characterized in that it comprises the following steps: a) adding and mixing at least one water-soluble polymer and at least one surfactant to the mining residue in order to obtain a conditioned mining residue; b) draining the conditioned mining residue by mechanical filtration in order to obtain a drained mining residue; the mechanical filtration is carried out by means of a filter press; the water-soluble polymer(s) being selected from: - water-soluble anionic polymers with a molecular weight between 800,000 and 3,000,000 g / mol; - water-soluble cationic polymers with a molecular weight between 10,000 and 3,000,000 g / mol; and - mixtures thereof, the surfactant(s) being chosen from among: - anionic surfactants; - non-ionic surfactants; and - mixtures thereof.

2. Method according to claim 1, characterized in that the water-soluble polymer and the surfactant are added at the same injection point, one after the other, the polymer being added before the surfactant.

3. Method according to claim 1 or 2, characterized in that the water-soluble anionic polymer consists of one or more hydrophilic anionic monomers and optionally hydrophilic nonionic monomers.

4. Method according to claim 3, characterized by the fact that the water-soluble anionic polymer consists of one or more hydrophilic anionic monomers selected from acrylic acid; methacrylic acid; dimethylacrylic acid; itaconic acid; itaconic acid hemiester; itaconic anhydride; itaconamide; crotonic acid; maleic acid; fumaric acid; acrylamido undecanoic acid; 3-acrylamido 3-methylbutanoic acid; maleic anhydride; strong acid monomers with, for example, a sulfonic acid or phosphonic acid function, such as vinylsulfonic acid, vinylphosphonic acid, allylsulfonic acid, metalylsulfonic acid, 2-methylidenepropane-1,3-disulfonic acid, 2-sulfoethyl methacrylate, sulfopropyl methacrylate, sulfopropyl acrylate, allylphosphonic acid, styrene sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, 2-acrylamido-2-methylpropane disulfonic acid;Water-soluble salts of these monomers, such as alkali metal, alkaline earth metal or ammonium salts; and mixtures thereof; and optionally of one or more hydrophilic nonionic monomers selected from acrylamide, methacrylamide, N-alkylacrylamides, N-alkylmethacrylamides, N,N-dialkylacrylamides, N,N-dialkylmethacrylamides, alkoxylated esters of acrylic acid, alkoxylated esters of methacrylic acid, N-vinylpyrrolidone, N-methylocrylamide, N-vinylformamide, N-vinylacetamide, N-vinylimidazole, N-vinylsuccinimide, acryloylmorpholine, acryloyl chloride, glycidyl methacrylate, glyceryl methacrylate, diacetone acrylamide, hydroxyalkyl (meth)acrylate, thioalkyl (meth)acrylate, hydroxyalkylacrylates, hydroxyalkyl methacrylates, and mixtures thereof.

5. Method according to claim 1 or 2, characterized in that the water-soluble cationic polymer consists of one or more hydrophilic cationic monomers and optionally hydrophilic non-ionic monomers.

6. Method according to claim 5, characterized in that the water-soluble cationic polymer consists of one or more hydrophilic cationic monomers selected from diallyldialkyl ammonium salts; acidified or quaternized salts of dialkylaminoalkylacrylamides; acidified or quaternized salts of dialkylaminoalkylmethacrylamides; acidified or quaternized salts of dialkylaminoalkyl acrylate; acidified or quaternized salts of dialkylaminoalkyl methacrylate; and mixtures thereof;and optionally of one or more hydrophilic nonionic monomers selected from acrylamide, methacrylamide, N-alkylacrylamides, N-alkylmethacrylamides, N,N-dialkylacrylamides, N,N-dialkylmethacrylamides, alkoxylated esters of acrylic acid, alkoxylated esters of methacrylic acid, N-vinylpyrrolidone, N-methylocrylamide, N-vinylformamide, N-vinylacetamide, N-vinylimidazole, N-vinylsuccinimide, acryloylmorpholine, acryloyl chloride, glycidyl methacrylate, glyceryl methacrylate, diacetone acrylamide, hydroxyalkyl (meth)acrylate, thioalkyl (meth)acrylate, hydroxyalkylacrylates, hydroxyalkyl methacrylates, and mixtures thereof.

7. A method according to any one of claims 1 to 4, characterized in that the water-soluble polymer is a water-soluble anionic polymer consisting of 5 to 100 mol% of hydrophilic anionic monomer and 0 to 95 mol% of hydrophilic nonionic monomer, based on the total amount of monomers in the water-soluble anionic polymer.

8. Method according to claim 5 or 6, characterized in that the water-soluble polymer is a water-soluble cationic polymer consisting of 5 to 100 mol% of hydrophilic cationic monomer and 0 to 95 mol% of hydrophilic non-ionic monomer, based on the total amount of monomers in the water-soluble cationic polymer.

9. Method according to any one of claims 1 to 8, characterized in that the water-soluble polymer is free of crosslinking agents. Petition 870250115183, dated 12 / 15 / 2025, pp. 50 / 51 4 / 4 10. Method according to claim 8, characterized in that the water-soluble polymer is a cationic polyamine obtained by condensation between epichlorohydrin and dimethylamine and has a molecular weight between 10,000 and 800,000 g / mol.

11. A method according to any one of claims 1 to 10, characterized in that the mining residue originates from the exploration of ores, drilling muds.

12. A method according to any one of claims 1 to 11, characterized in that the amount of water-soluble polymer added to the mining tailings is between 0.5 and 5,000 ppm, based on the dry weight of the mining tailings to be conditioned; and in that the amount of surfactant added to the mining tailings is between 10 and 10,000 ppm, based on the dry weight of the mining tailings to be conditioned.

13. Method according to any one of claims 1 to 12, characterized in that, at the end of the drainage stage, the cake is dried under an airflow. Petition 870250115183, dated 12 / 15 / 2025, p. 51 / 51