OA19878A - Controlling the rheology of a metal ore residue. - Google Patents

Controlling the rheology of a metal ore residue. Download PDF

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Publication number
OA19878A
OA19878A OA1202000417 OA19878A OA 19878 A OA19878 A OA 19878A OA 1202000417 OA1202000417 OA 1202000417 OA 19878 A OA19878 A OA 19878A
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OA
OAPI
Prior art keywords
métal
chosen
less
aqueous
preferentially
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OA1202000417
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French (fr)
Inventor
Mehdi Bouzid
Christian Jacquemet
Benoît Magny
Jacques Mongoin
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Coatex
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Publication of OA19878A publication Critical patent/OA19878A/en

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Abstract

The invention concerns a method for preparing an aqueous mineral suspension from an aqueous metal ore residue into which a polymer (P) is introduced having a molecular mass Mw measured by GPC ranging from 2.000 to 20.000 g/mol and prepared by radical polymerisation of at least one anionic monomer (M). The invention also concerns the suspension produced, the Brookfield viscosity of which is lower than 1,800 mPa.s or the yield point of which is lower than 80 Pa.

Description

Coatex CONTROLLING THE RHEOLOGY OF A METAL ORE RESIDUE
DESCRIPTION
The invention relates to a method for preparing an aqueous minerai suspension from an aqueous métal ore residue into which is introduced a polymer (P) with a molecular mass Mw, measured by GPC, ranging from 2,000 to 20,000 g/mol and prepared by radical polymérisation of at least one anionic monomer (M). The invention also relates to the suspension produced whose Brookfield viscosity is less than 1,800 mPa.s or whose flow threshold is less than 80 Pa.
The method according to the invention is used in a mining process involving at least one minerai deposit. These mining methods generally make it possible to obtain at least one useable métal from a métal ore. The métal ore also comprises a residue of this métal ore. The mining methods are usually implemented using water as a medium for processing or conveying the dry solids content. Therefore, the métal ore residue is usually an aqueous métal ore residue. It can also be a sludge of métal ore residue. It can also be a muddy residue of ore. .
According to the invention^ the aqueous métal ore residue thus results from at least one step in which the useable métal or a dérivative of the useable métal is separated from a métal ore, in particular a métal ore produced by mining extraction. According to the invention, the fraction of the useable métal ore is a métal or several metals or a dérivative of a métal or a dérivative of several metals.
When using the method of préparation according to the invention, an essential step consists of adding at least one polymer (P) to an aqueous métal ore residue. This step therefore relates to the processing of a métal ore residue. It does not relate to the processing of the useable métal ore. This step is therefore generally used in a mining method comprising various steps for processing the métal ore and various steps for processing the métal ore residue.
Typically, mining methods comprise several steps' for processing the métal ore, several steps for processing the, useable métal or for processing the dérivative of the useable métal as well as several steps for processing the métal ore residue.
A mining method typically comprises one or more of the following steps:
- ’ crushing the métal ore,
- grinding the..metal ore, in p articulai, drygrindingorwct grinding, usually in water,
- separating, in particular by flotation, the useable métal or a dérivative of the useable métal and the métal ore residue, particularly the aqueous residue,
- purifying or enriching the useable métal or a dérivative of the useable métal, in particular by flotation,
- concentrating the métal ore residue, for example by filtration, by settling, by gravity, by using a thickener, by flocculation,
- partially separating the aqueous métal ore residue and part of the water,
- conveying the aqueous métal ore residue and
- storing the aqueous métal ore residue.
There are known methods for preparing an aqueous minerai suspension from an aqueous métal ore residue, particularly the methods used to process, convey or store such a residue. Document GB 1414964 relates to a method for deflocculating a particulate material that consists of adding a copolymer or a water-soluble dérivative of a vinyl copolymer to a grout of the particulate material.
Document WO 2007-082797 describes a method for concentrating an aqueous suspension of solid particles combining the use of a flocculant polymer and the use of radiation or of radical agents, oxidising agents or enzymes.
Document WO 2017-097799 discloses a method for processing an aqueous effluent resulting from oil sands mining operations that comprises the addition of a sulphonated dispersing agent and then the addition of a flocculating agent.
Document WO 00-43317 discloses the use of a viscosity-modifying compound in a sludge thickener in which this compound is incorporated into a thickener in a spécifie way.
To facilitate their handling, the known suspensions typically hâve a lower solids content. In fact, adding water may help to lower the viscosity or the flow threshold of these suspensions.
However, adding water leads to problems with water consumption, energy consumption or even problems with organising and storing the aqueous métal ore residues.
It is therefore important to hâve methods for preparing an aqueous minerai suspension from an aqueous métal ore residue having a high dry solids content.
It is also important to hâve such methods that make it possible to préparé stable suspensions, in particular at high dry solids contents. Likewise, it is important to hâve such methods which make it possible to préparé suspensions that are stable and in which the particles of dry solids content hâve a particle size distribution that is relatively coarse or is not very uniform.
Compatibility with the various constituents of aqueous minerai suspensions prepared from an aqueous métal ore residue is also an important property to look for, in particular compatibility with a flocculation agent that can be used to process aqueous métal ore residue, in particular compatibility with a polyacrylamide or a polyacrylamide dérivative. Likewise, it is important to be able to control the viscosity of aqueous minerai suspensions prepared from a mining dérivative, in particular to make it easier to pump, stir or convey them.
Moreover, it is important to hâve methods that make it possible to control the flow threshold of the aqueous métal ore residue.
It is particularly important to confer on an aqueous métal ore residue a flow threshold with a minimum threshold value that makes it possible to eliminate or reduce the risk of the solid portion of the residue settling in case there is no shearing or if there is slight shearing. Reducing the consumption of water when processing aqueous métal ore residues should also be sought.
Water recovery or recycling during the various steps in the mining methods is also to be preferred.
Both the amount of water that is separated or recycled and the quality of the separated or recycled water should be sought.
It is also important to be able to control the behaviour of the aqueous minerai suspensions prepared from an aqueous métal ore residue in order to avoid problems with the processing, storage or conveying equipment. Indeed, this equipment can be damaged, jammed or clogged if there is a drift in or lack of control of the viscosity or of the flow threshold of a minerai suspension prepared from an aqueous métal ore residue.
There is therefore a need for improved methods for preparing an aqueous minerai suspension from an aqueous métal ore residue.
The method according to the invention provides a solution to ail or part of the problems with the methods used in the prior art to préparé an aqueous minerai suspension from an aqueous métal ore residue.
Thus, the invention provides a method for preparing an aqueous minerai suspension with a dry solids content that is greater than 40% by weight of the suspension and having at least one property chosen among:
- a Brookfield viscosity, measured at 100 rpm and at 25°C, of less than 1,800 mPa.s,
- a flow threshold, measured at a température of 25 °C using a rheometer with imposed shearing, equipped with a bladed spindle, for a particular torsional loading, of less than 80 Pa and
- a Brookfield viscosity, measured at 100 rpm and at 25°C, of less than 1,800 mPa.s and a flow threshold, measured at a température of 25 °C using a rheometer with imposed shearing, equipped with a bladed spindle, for a particular torsional loading, of less than 80 Pa, comprising the addition, in an aqueous métal ore residue, of at least one polymer (P) with a molecular mass Mw, measured by GPC, ranging from 2,000 to 20,000 g/mol and prepared by at least one radical polymérisation reaction, at a température greater than 50°C, of at least one anionic monomer (M) comprising at least one polymerisable olefinic unsaturation and at least one carboxylic acid group or one of its salts, in the presence of at least one radical-generating compound chosen among hydrogen peroxide, benzoyl peroxide, acetyl peroxide, laurel peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, ammonium persulphate, an alkaline métal persulphate, preferably sodium persulphate or potassium persulphate, an azo compound such as 2,2'-azobis(2-(4,5-dihydroimidazolyl)propane, 2,2'-azobis(2-methylpropionamidine) dihydrochloride, diazo-valeronitrile, 4,4'-azobis-(4-cyanovaleric) acid, AZDN or 2,2'-azobisisobutyronitrile, and their respective combinations or associations with an ion chosen among Fe11, Fein, Cu1, Cu11 and mixtures thereof.
The method according to the invention therefore makes it possible to control the essential properties of the aqueous suspension prepared. This method makes it possible to control both the Brookfield viscosity and the flow threshold of the prepared suspension.
According to the invention, the Brookfield viscosity is measured at 100 rpm and at 25 °C, for example using a Brookfield DV3T rheometer. The Brookfield viscosity of the prepared suspension is less than 1,800 mPa.s. Preferably, the method according to the invention makes it possible to préparé a suspension with a viscosity of less than 1,500 mPa.s or less than 1,200 mPa.s. More preferably, the viscosity is less than 1,000 mPa.s or less than 900 mPa.s. Much more preferentially, the viscosity is less than 800 mPa.s or less than 700 mPa.s or even less than 500 mPa.s.
Particularly advantageously, the method according to the invention makes it possible to control, in particular to lower, the flow threshold of the aqueous métal ore residue relative to the flow threshold of the aqueous métal ore residue that does not comprise any polymer (P).
According to the invention, the flow threshold, which characterises the flow résistance, is measured on a sample of an aqueous minerai suspension, particularly of an aqueous métal ore residue. The flow threshold is the shearing that must be applied to a suspension to cause it to flow. If the shearing is insufficient, the suspension deforms elastically whereas if the shearing is sufficient, the suspension can flow like a liquid.
According to the invention, the flow threshold expressed in Pascals (Pa) is measured at a température of 25°C using a Brookfield DV3T rheometer with imposed shearing, equipped with a suitable spindle with blades. Without destroying the underlying structure, the bladed spindle is immersed into the material up to the first immersion mark. After a five-minute wait time, the measure is taken without pre-shearing at a speed of 0.5 rpm. This relatively low speed is preferred so as to minimise the inertia effect of the bladed spindle. The variation in torsional loading measured by the instrument in order to maintain a spin speed of 0.5 rpm is tracked over time. The value of the flow limit or flow threshold of the aqueous residue is indicated by the instrument when this variation becomes zéro.
According to the invention, the flow threshold is measured at a température of 25°C using a rheometer with imposed shearing, equipped with a bladed spindle, for a particular torsional loading. The flow threshold of the prepared suspension is less than 80 Pa. Preferably, the method according to the invention makes it possible to préparé a suspension that has a flow threshold of less than 70 Pa or less than 60 Pa. More preferably, the flow threshold is less than 50 Pa or less than 40 Pa. More preferentially, the flow threshold is less than 30 Pa or less than 20 Pa.
Also preferably, the method according to the invention makes it possible to préparé a suspension that has a flow threshold greater than 10 Pa. More preferentially, the flow threshold is greater than 12 Pa. Even more preferentially, the flow threshold is greater than 15 Pa.
Thus, the flow threshold is greater than 10 Pa, preferably greater than 12 Pa, more preferentially greater than 15 Pa and less than 70 Pa or less than 60 Pa, preferably less than 50 Pa or less than 40 Pa, more preferentially less than 30 Pa or less than 20 Pa.
Preferably, the flow threshold of the suspension according to the invention ranges from to 80 Pa, or to 70 Pa, to 60 Pa, to 50 Pa, to 40 Pa, to 30 Pa or to 20 Pa. Also preferably, the flow threshold of the suspension according to the invention ranges from 12 to 80 Pa, or to 70 Pa, to 60 Pa, to 50 Pa, to 40 Pa, to 30 Pa or to 20 Pa. Also preferably, the flow threshold of the suspension according to the invention ranges from 15 to 80 Pa, or to
Pa, to 60 Pa, to 50 Pa, to 40 Pa, to 30 Pa or to 20 Pa.
The method according to the invention makes it possible to control the rheology of the prepared suspension for a dry solids content greater than 40% by weight of the suspension. Preferably, the method according to the invention makes it possible to préparé a suspension having a dry solids content greater than 50% by weight or 55% by weight. More preferably, the method according to the invention makes it possible to préparé a suspension having a dry solids content greater than 60% by weight or greater than 65% by weight. Much more preferentially, the method according to the invention makes it possible to préparé a suspension having a dry solids content greater than 70% by weight or greater than 75% by weight.
According to the invention, the amount of polymer (P) used may vary quite widely. Preferably according to the invention, the prepared suspension comprises from 0.01 to 2% by weight or from 0.01 to 1.8% or from 0.01 to 1.5% of polymer (P) (dry/dry relative to the ore residue). More preferentially, the prepared suspension comprises from 0.01 to 1.2% or from 0.01 to 1% or from 0.02 to 0.8% or from 0.03 to 0.5% or from 0.04 to 0.25% or from 0.04 to 0.15% by weight of polymer (P) (dry/dry relative to the ore residue).
The method according to the invention may use one or more polymers (P). Preferably, the suspension prepared thus comprises one, two or three different polymers (P). The method according to the invention may also comprise the further addition of at least one compound chosen among a lignosulphonate dérivative, a silicate, an unmodifïed polysaccharide and a modified polysaccharide.
The method according to the invention comprises the addition of at least one polymer (P) to an aqueous minerai ore residue. Preferably, the métal ore is not an aluminium ore. Also preferably according to the invention, the métal ore is chosen among lithium, strontium, lanthanide, actinide, uranium, rare earth, titanium, zirconium, vanadium, niobium, chromium, molybdenum, tungsten, manganèse, iron, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, tin and lead ores. More preferably according to the invention, the métal ore is chosen among uranium, molybdenum, manganèse, iron, cobalt, nickel, copper, silver and gold ores. Much more preferably, it is a copper ore. It can also be a dérivative of several useable metals comprising copper, zinc and cobalt.
According to the invention, the métal ore comprises at least one useable métal or at least one useable métal dérivative obtained by separating ail or part of the residue from the métal ore. Preferably according to the invention, the métal ore comprises a métal oxide, a métal sulphide or a métal carbonate.
According to the invention, the métal ore residue may comprise a certain residual amount of métal. Particularly, the métal ore residue may comprise a residual amount of métal of less than 2,000 g per tonne (dry/dry) relative to the amount of métal ore residue. This amount of métal in the métal ore residue can typically range from 10 to 2,000 g per tonne (dry/dry) or from 10 to 1,000 g per tonne (dry/dry), relative to the amount of métal ore residue.
When using the method according to the invention, the polymer (P) can be added during one or several steps in the mining process, in particular during one or several of the métal ore residue processing steps such as pumping, flocculating, concentrating, conveying or storing the métal ore residue, particularly the aqueous métal ore residue.
According to the invention, during a step of concentration of the aqueous métal ore residue according to the invention, the concentration of the aqueous métal ore residue is significantly increased. Preferably, the concentration of the aqueous métal ore residue is increased from 10 to 40% by weight or from 20 to 40% by weight or from 10 to 50% by weight or from 20 to 50% by weight. Also preferably, the concentration of the aqueous métal ore residue is increased from 10 to 70% by weight or from 20 to 70% by weight or from 10 to 60% by weight or from 20 to 60% by weight.
Preferably according to the invention, the polymer (P) is added:
- before a step of pumping the aqueous métal ore residue, in particular using a pump chosen among a centrifugal pump, a peristaltic pump, a positive displacement pump, a compressed air pump, a diaphragm pump, a rotary pump or
- during a pumping step of the aqueous métal ore residue, in particular using a pump chosen among a centrifugal pump, a peristaltic pump, a positive displacement pump, a compressed air pump, a diaphragm pump, a rotary pump or
- after a step of pumping the aqueous métal ore residue, in particular using a pump chosen among a centrifugal pump, a peristaltic pump, a positive displacement pump, a compressed air pump, a diaphragm pump, a rotary pump.
Also preferably according to the invention, the polymer (P) is added:
- before a step of flocculation of the aqueous métal ore residue, for example using a polyacrylamide or a polyacrylamide dérivative or
- during a step of flocculation of the aqueous métal ore residue, for example using a polyacrylamide or a polyacrylamide dérivative such as alkylene bis-acrylamide, particularly ethylene bis-acrylamide or
- after a step of flocculation of the aqueous métal ore residue, for example using a polyacrylamide or a polyacrylamide dérivative such as alkylene bis acrylamide, particularly ethylene bis-acrylamide.
Also preferably according to the invention, the polymer (P) is added:
- before a step of concentration of the aqueous métal ore residue, in particular by gravimétrie concentration, for example using at least one device chosen among a conventional thickener, a high-density thickener, a high-yield thickener, or by densimetric concentration, for example using at least one device chosen among a conventional thickener, a high-density thickener, a high-yield thickener, or by filtration, for example using at least one device chosen among a filter, a filter press, a rotary filter or
- during a step of concentration of the aqueous métal ore residue, in particular by gravimétrie concentration, for example using at least one device chosen among a conventional thickener, a high-density thickener, a high-yield thickener, or by densimetric concentration, for example using at least one device chosen among a conventional thickener, a high-density thickener, a high-yield thickener, or by filtration, for example using at least one device chosen among a filter, a filter press, a rotary filter or
- after a step of concentration of the aqueous métal ore residue, in particular by gravimétrie concentration, for example using at least one device chosen among a conventional thickener, a high-density thickener, a high-yield thickener, or by densimetric concentration, for example using at least one device chosen among a conventional thickener, a high-density thickener, a high-yield thickener, or by filtration, for example using at least one device chosen among a filter, a filter press, a rotary filter.
Also preferably according to the invention, the polymer (P) is added before a step of conveying of the aqueous métal ore residue, in particular conveying using an open pipe, a closed pipe or a pipeline.
Also preferably according to the invention, the polymer (P) is added before a step of storing the aqueous métal ore residue or during a step of storing the aqueous métal ore residue.
Particularly preferably according to the invention, the polymer (P) is added:
- before a step of pumping the aqueous métal ore residue, in particular using a pump chosen among a centrifugal pump, a peristaltic pump, a positive displacement pump, a compressed air pump, a diaphragm pump, a rotary pump or
- during a step of pumping the aqueous métal ore residue, in particular using a pump chosen among a centrifugal pump, a peristaltic pump, a positive displacement pump, a compressed air pump, a diaphragm pump, a rotary pump or
- after a step of concentration of the aqueous métal ore residue, in particular by gravimétrie concentration, for example using at least one device chosen among a conventional thickener, a high-density thickener, a high-yield thickener, or by densimetric concentration, for example using at least one device chosen among a conventional thickener, a high-density thickener, a high-yield thickener, or by filtration, for example using at least one device chosen among a filter, a filter press, a rotary filter or
- before a step of conveying the aqueous métal ore residue, in particular conveying using an open pipe, a closed pipe or a pipeline.
Even more particularly preferably according to the invention, the polymer (P) is added:
- before a step of pumping the aqueous métal ore residue, in particular using a pump chosen among a centrifugal pump, a peristaltic pump, a positive displacement pump or
- during a step of pumping the aqueous métal ore residue, in particular using a pump chosen among a centrifugal pump, a peristaltic pump, a positive displacement pump, a compressed air pump, a diaphragm pump, a rotary pump or
- after a step of concentration of the aqueous métal ore residue, in particular by gravimétrie concentration, for example using at least one device chosen among a conventional thickener, a high-density thickener, a high-yield thickener or
- before a step of conveying the aqueous métal ore residue, in particular conveying using a closed pipe or a pipeline.
The method according to the invention uses at least one particular polymer (P). It is prepared by a polymérisation reaction in the presence of at least one radical-generating compound chosen among hydrogen peroxide, benzoyl peroxide, acetyl peroxide, laurel peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, ammonium persulphate, an alkaline métal persulphate, preferably sodium persulphate or potassium persulphate, an azo compound such as 2,2'-azobis(2-(4,5-dihydroimidazolyl)propane, 2,2'-azobis(2-methylpropionamidine) dihydrochloride, diazo-valeronitrile, 4,4'-azobis-(4-cyanovaleric) acid, AZDN or 2,2'-azobisisobutyronitrile, and their respective combinations or associations with an ion chosen among Fe11, Fem, Cu1, Cu11 and mixtures thereof. Preferably, this polymérisation reaction does not use benzoyl peroxide.
In addition to this radical-generating compound, the polymérisation reaction can be carried out in the presence of at least one compound comprising phosphorus in the oxidation I state, preferably a compound chosen among hypophosphorous acid (H3PO2) and a dérivative of hypophosphorous acid (H3PO2), preferably a compound comprising at least one hypophosphite ion (ΙΙ2ΡΟ2'), more preferentially a compound chosen among sodium hypophosphite (ILPC^Na), potassium hypophosphite (H2PO2K), calcium hypophosphite ([H2PO2]2Ca) and mixtures thereof.
Likewise, the polymérisation reaction can be carried out in the presence of at least one compound comprising phosphorus in the oxidation III state, preferably a compound chosen among phosphorous acid and a dérivative of phosphorous acid, more preferentially a compound comprising at least one phosphite ion, in particular a compound chosen among sodium phosphite, calcium phosphite, potassium phosphite, ammonium phosphite and combinations thereof.
The polymérisation reaction can also be carried out in the presence of at least one compound comprising a bisulphite ion, preferably a compound chosen among ammonium bisulphite, an alkaline métal bisulphite, in particular sodium bisulphite, potassium bisulphite, calcium bisulphite, magnésium bisulphite and combinations thereof.
The polymérisation reaction can also be carried out in the presence of from 0.05 to 5% by weight, relative to the total amount of monomers, of at least one compound chosen among a xanthate dérivative, a mercaptan compound and a compound of formula (I):
R S F
XœC'^^S^COOX (I) wherein:
ο X independently represents H, Na or K and o R independently represents a Ci-Cs-alkyl group, preferably a methyl group;
particularly a compound of formula (I) which is disodic diisopropionate trithiocarbonate (DPTTC).
According to the invention, the polymérisation reaction is carried out at a température greater than 50°C. Preferably, the polymérisation reaction is carried out at a température ranging from 50 to 98°C or from 50 to 95°C or from 50 to 85°C. A higher température, in particular above 100°C, may be used by adjusting the pressure of the reaction medium to prevent évaporation.
Preferably, the polymérisation reaction is carried out in water. It can also be carried out in a solvent, alone or mixed with water, in particular an alcoholic solvent, particularly isopropyl alcohol. More preferably, it is carried out in water.
Advantageously, the polymer (P) used according to the invention has a molecular mass Mw, measured by GPC, ranging from 2,200 to 10,000 g/mol. Preferably, the polymer (P) used according to the invention has a molecular mass Mw ranging from 2,400 to 9,500 g/mol or from 2,400 to 8,000 g/mol, more preferentially from 2,400 to 6,500 g/mol. The polymer (P) used according to the invention is therefore not a flocculating agent. According to the invention, the molecular mass Mw of the copolymers is determined by Gel Perméation Chromatography (GPC). This technique uses a Waters liquid chromatography apparatus equipped with a detector. This detector is a Waters refractive index detector. This liquid chromatography apparatus is equipped with a steric exclusion column in order to separate the various molecular weights of the copolymers studied. The liquid elution phase is an aqueous phase adjusted to pH 9.00 using IN sodium hydroxide containing 0.05 M of NaHCO3, 0.1 M of NaNO3, 0.02 M of triethanolamine and 0.03% of NaN3.
According to a first step, the copolymer solution is diluted to 0.9% by dry weight in the dissolution solvent of the GPC, which corresponds to the liquid elution phase of the GPC to which is added 0.04% of dimethyl formamide which acts as a flow rate marker or internai standard. Then it is filtered using a 0.2 pm filter. Then 100 pL are injected into the chromatography instrument (eluent: an aqueous phase adjusted to pH 9.00 by IN sodium hydroxide containing 0.05 M of NaHCO3, 0.1 M of NaNO3, 0.02 M of triethanolamine and 0.03% of NaN3). The liquid chromatography apparatus has an isocratic pump (Waters 515) the flow rate of which is set to 0.8 mL/min. The chromatography instrument also comprises an oven which itself comprises the following system of columns in sériés: a Waters Ultrahydrogel Guard precolumn 6 cm long and mm in inner diameter and a Waters Ultrahydrogel linear column 30 cm long and
7.8 mm in inner diameter. The détection system is comprised of a Waters 410 RI refractive index detector. The oven is heated to 60°C and the refractometer is heated to 45°C.
The chromatography instrument is calibrated using powdered sodium polyacrylate standards of different molecular masses certified by the supplier: Polymer Standards Service or American Polymers Standards Corporation (molecular mass ranging from 900 to 2.25 x 106 g/mol and polymolecularity index ranging from 1.4 to 1.8).
The polymer (P) used according to the invention can be completely or partially neutralised, in particular at the end of the polymérisation reaction. According to the invention, the neutralisation of the polymer is carried out by neutralising or salifying ail or part of the carboxylic acid groups présent in the polymer. Preferably, this neutralisation is carried out using a base, for example using a dérivative of an alkaline métal or a dérivative of an alkaline-earth métal.
The preferred bases are chosen among CaO, ZnO, MgO, NaOH, KOH, NH4OH, Ca(OH)2, Mg(OH)2, monoisopropylamine, triethanolamine, triisopropylamine, 2-amino-2-methyl-l-propanol (AMP), triethylamine, diethylamine, monoethylamine. Particularly preferably, neutralisation is carried out using MgO, NaOH, KOH, Ca(OH)2, Mg(OH)2, alone or in combination.
According to the invention, the polymérisation reaction uses at least one anionic monomer (M) comprising at least one polymerisable olefinic unsaturation and at least one carboxylic acid group or one of its salts.
Preferably, the anionic monomer (M) comprising at least one polymerisable olefinic unsaturation comprises one or two carboxylic acid groups, particularly a single carboxylic acid group. More preferably, it is chosen among acrylic acid, methacrylic acid, an acrylic acid sait, a methacrylic acid sait and mixtures thereof, much more preferentially acrylic acid.
Preferably, the polymérisation reaction uses 100% by weight of anionic monomer (M) or from 70% to 99.5% by weight of anionic monomer (M) and from 0.5% to 30% by weight of at least one other monomer.
Advantageously, the polymérisation reaction can thus also use at least one other monomer chosen among:
- another anionic monomer, preferably a monomer chosen among acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride and mixtures thereof,
- 2-acrylamido-2-methylpropanesulphonic acid, a sait of 2-acrylamido-2methylpropanesulphonic acid, 2-(methacryloyloxy)ethanesulphonic acid, a sait of 2-(methacryloyloxy)ethanesulphonic acid, sodium methallyl sulphonate, styrene sulphonate and combinations or mixtures thereof,
- a non-ionic monomer comprising at least one polymerisable olefïnic unsaturation, preferably at least one polymerisable ethylenic unsaturation and in particular a polymerisable vinyl group, more preferentially a non-ionic monomer chosen among styrene, vinyl caprolactam, the esters of an acid comprising at least one monocarboxylic acid group, in particular an ester of an acid chosen among acrylic acid, methacrylic acid and mixtures thereof, for example hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl méthacrylate, hydroxypropyl méthacrylate, alkyl acrylate, in particular Cj-Cio-alkyl acrylate, preferentially Ci-C4-alkyl acrylate, more preferentially methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, isobutyl acrylate, n-butyl acrylate, alkyl méthacrylate, in particular Ci-Cio-alkyl méthacrylate, preferentially Ci-C4-alkyl méthacrylate, more preferentially methyl méthacrylate, ethyl méthacrylate, n-propyl méthacrylate, isopropyl méthacrylate, isobutyl méthacrylate, n-butyl méthacrylate, aryl acrylate, preferably phenyl acrylate, benzyl acrylate, phenoxyethyl acrylate, aryl méthacrylate, preferably phenyl méthacrylate, benzyl méthacrylate, phenoxyethyl méthacrylate and
- a monomer of formula (II):
R1
G!) wherein:
- R1 and R2, identical or different, independently represent H or CH3,
- L1 independently represents a group chosen among C(O), CHz, CH2-CH2 and O-CH2-CH2-CH2-CH2,
- L2 independently represents a group chosen among (CH2-CH2O)X, (CH2CH(CH3)O)y, (CH(CH3)CH2O)z and combinations thereof and
- x, y and z, identical or different, independently represent an integer or décimal comprised in a range from 0 to 150 and the sum of x+y+z is comprised in a range from 10 to 150.
Particularly preferably, the monomer of formula (II) is such that:
- R1 represents CH3,
- R2 represents H,
- L1 represents a C(O) group,
- L2 independently represents a combination of groups chosen among (CH2-CH2O)x, (CH2CH(CH3)O)y, (CH(CH3)CH2O)Z and
- x, y and z, identical or different, independently represent an integer or décimal comprised in a range from 0 to 150 and the sum of x+y+z is comprised in a range from 10 to 150.
Preferably, the polymer (P) used according to the invention is a non-sulphonated polymer.
When preparing the polymer (P) used according to the invention, a séparation step can also be carried out.
According to the invention, the séparation can be carried out after the full or partial neutralisation of the polymer (P).
It can also be carried out prior to neutralising the polymer (P).
The aqueous solution of the fuliy or partially neutralised polymer (P) can be processed using the static or dynamic split methods known as such.
To do so, one or more polar solvents in the group comprised in particular of methanol, éthanol, n-propanol, isopropanol, butanol, acetone and tetrahydrofuran, can be used, thus resulting in a two-phase séparation.
During the séparation, the least dense phase contains the largest fraction of the polar solvent and the fraction of polymers with low molecular weight, and the densest aqueous phase contains the fraction of polymers with the highest molecular weight.
The température at which the polymer fraction sélection is processed can influence the partition coefficient. It is typically comprised within a range of from 10 to 80°C, preferably from 20 to 60°C. During the séparation, it is important to control the ratio of the amounts of dilution water and polar solvents.
When using a dynamic séparation method, for example centrifugation, the ratios of the extracted fractions typically dépend on the centrifugation conditions. The sélection of the fraction of the polymers can also be improved by re-processing the densest aqueous phase using a new amount of polar solvent, which can be different. It can also be a mixture of polar solvents. Lastly, the liquid phase obtained after processing can be distilled to eliminate the solvent(s) used in processing.
The method of préparation according to the invention makes it possible to préparé a suspension of aqueous métal ore residue comprising at least one polymer (P) that has particularly advantageous properties, in particular rheological properties that are particularly advantageous.
Thus, the invention also provides a method for preparing an aqueous minerai suspension with a dry solids content that is greater than 50% by weight of the suspension and having at least one property chosen among:
- a Brookfîeld viscosity, measured at 100 rpm and at 25°C, of less than 1,800 mPa.s, - a flow threshold measured at a température of 25 °C using a rheometer with imposed shearing, equipped with a bladed spindle, for a particular torsional loading, of less than 80 Pa and
- a Brookfîeld viscosity, measured at 100 rpm and at 25°C, of less than 1,800 mPa.s and a flow threshold, measured at a température of 25°C using a rheometer with imposed shearing, equipped with a bladed spindle, for a particular torsional loading, of less than 80 Pa, comprising an aqueous métal ore residue and at least one polymer (P) with a molecular mass Mw, measured by GPC, ranging from 2,000 to 20,000 g/mol and prepared by radical polymérisation reaction, at a température greater than 50°C, of at least one anionic monomer (M) comprising at least one polymerisable olefinic unsaturation and at least one carboxylic acid group or one of its salts, in the presence of at least one radical-generating compound chosen among hydrogen peroxide, benzoyl peroxide, acetyl peroxide, laurel peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, ammonium persulphate, an alkaline métal persulphate, preferably sodium persulphate or potassium persulphate, an azo compound such as 2,2'-azobis(2-(4,5-dihydroimidazoIyl)propane, 2,2'-azobis(2-methylpropionamidine) dihydrochloride, diazo-valeronitrile, 4,4'-azobis-(4-cyanovaleric) acid, AZDN or 2,2'-azobisisobutyronitrile, and their respective combinations or associations with an ion chosen among Fe11, Fe111, Cu1, Cu11 and mixtures thereof.
The particular, advantageous or preferred characteristics of the method according to the invention define suspensions according to the invention which are also particular, advantageous or preferred.
EXAMPLES
The following examples illustrate the various aspects of the invention.
The polymers used in the method according to the invention are prepared.
Polymer (Pl) is prepared by placing 156 g of water and 0.013 g of iron sulphate heptahydrate into a one-litre glass reactor with mechanical stirring and oil bath heating.
Using a dosing pump, 271 g of acrylic acid at 100% by weight are weighed into a 500 mL beaker.
Using a dosing pump, 3.3 g of persulphate diluted with 15 g of water are weighed into a 20 mL test tube .
Using a dosing pump, 115 g of sodium bisulphite at 40% by weight are weighed into a 200 mL test tube.
The reactor is heated to 80°C.
30% ofthe persulphate solution is injected rapidly and then the remainder ofthis solution, the acrylic acid and the bisulphite solution are injected in parallel in:
- 3 h for the acrylic acid and
- 3.5 h for the persulphate and the bisulphite.
The reaction medium is kept at 80°C.
The medium is then heat-treated for 30 minutes with a solution of 0.3 g of persulphate in 4 g of water and then 4.5 g of hydrogen peroxide at 130 V.
Lastly, the pumps are rinsed with water.
The medium is heated again for 60 min at 80°C.
The solution is then neutralised using 50% by weight of sodium hydroxide in water until it reaches pH 8 and then diluted to a solids content of 42% by weight. Polymer (Pl) is obtained, with a molecular mass Mw, measured by GPC, of 2,500 g/mol.
Polymer (P2) is prepared by placing 212 g of water and 0.08 g of iron sulphate heptahydrate into a one-litre glass reactor with mechanical stirring and oil bath heating.
Using a dosing pump, 303 g of acrylic acid at 100% by weight and 15 g of water are weighed into a 500 mL beaker.
Using a dosing pump, 25.6 g of sodium hypophosphite monohydrate diluted with 30 g of water are weighed into a 100 mL test tube.
Using a dosing pump, 21g of hydrogen peroxide at 130 V and 35 g of water are weighed into a 100 mL test tube.
The reactor is heated to 95°C and the monomer, the hypophosphite solution and the hydrogen peroxide solution are added in parallel in 120 min while keeping the température ofthe reaction medium at 95°C.
Lastly, the pumps are rinsed with water.
The medium is heated again for 60 min at 95°C.
The solution is then neutralised using 50% by weight of sodium hydroxide in water until it reaches pH 8 and then diluted to a solids content of 42% by weight. Polymer (P2) is obtained, with a molecular mass, measured by GPC, of4,500 g/mol.
The raw material used for this sériés of tests is an aqueous métal ore residue from a Chilean copper mine located in the north of the country. This is waste resulting from the séparation of the ore containing the useable métal from the rock extracted from the mine. This aqueous copper ore residue is in the form of a water-based suspension.
Various measures were taken beforehand on the aqueous residue in the absence of the polymer according to the invention:
- particle size distribution using a Mastersizer 2000 laser granulometer (Malvem),
- solid content using a Mettler-Toledo dry balance,
- Brookfield viscosity at 100 rpm using a Brookfield DV3T viscometer with a suitable spindle,
- flow limit value using a Brookfield DV3T viscometer using a winged module and
- flow speed using a No. 4 Ford Cup viscometer.
The particle size distribution by volume shows the presence of multiple particle populations with different sizes: D(0.1) =1.6 pm, D(0.5) = 25 pm, D(0.84) = 195 pm, D(0.9) = 252 pm, and D(0.99) = 501 pm.
The other characteristics are shown in Table 1.
% Solids content 55.8
Brookfield viscosity at 100 rpm, in mPa.s 1,220
pH 10.0
Conductivity in pS/cm 2,700
Viscosity, No. 4 Ford cup, in s 25
Table 1
A concentration of the aqueous residue is then prepared by decanting and separating a portion of the supematant water to form an aqueous residue whose characteristics are
% Solids content 60.5
Brookfield viscosity at 100 rpm, in mPa.s 3,016
PH 10.1
Conductivity in pS/cm 2,320
Viscosity, No. 4 Ford cup, in s /
shown in Table 2.
Table 2
A sample of suspension of aqueous residue of reconcentrated copper ore is transferred into a 500 mL beaker and then mechanically stirred with a Raynerie mixer. Stirring varies from 800 to 1,000 rpm.
Then, a polymer (PI) according to the invention is added (0.1% by weight dry/dry) and the mixture is left under stirring for 5 to 10 min.
Stirring is then stopped to allow the Brookfield viscosities, pH and conductivity measures to be taken. The test is repeated, adding different amounts of polymer. The results are shown in Table 3.
Polymer (PI)
% by weight dry/dry of polymer Brookfield viscosity at 100 rpm (mPa.s) pH Conductivity (pS/cm)
0 3,032 9.9 2,410
0.07 1,374 9.9 2,580
0.09 1,186 9.9 2,560
0.1 1,070 9.9 2,590
Table 3
A dose of 0.1% by weight dry/dry of polymer (PI) makes it possible to significantly reduce the viscosity of the aqueous residue. The aqueous suspension of copper ore residue can then be handled easily.
Another test is conducted without any polymer and with two polymers (PI) and (P2) according to the invention at this dose of 0.1% by weight dry/dry. The results are shown in Table 4.
Residue
without additive with polymer (PI) with polymer (P2)
% by weight dry/dry 0 0.1 0.1
PH 10.1 9.9 9.3
Conductivity in 2,320 2,590 2,940
% Solids content 60.5 60.9 60.5
Brookfield viscosity at 100 rpm (mPa.s) 3,016 1,070 1,188
Table 4
A dose of 0.1% by weight dry/dry of polymer (Pl) or of polymer (P2) thus also makes it possible to signifïcantly reduce the viscosity of the aqueous residue.
The flow threshold of this aqueous copper ore residue with a solids content of 61% was then measured at a température of 25°C using a Brookfield DV3T rheometer with imposed shearing, equipped with a spindle with suitable blades. Without destroying the underlying structure, the bladed spindle is immersed into the material up to the first immersion mark. After a five-minute wait time, the measure is taken without pre-shearing at a speed of 0.5 rpm. This relatively low speed is preferred so as to minimise the inertia effect of the bladed spindle. The variation in torsional loading measured by the instrument in order to maintain a spin speed of 0.5 rpm is tracked over time.
The value of the flow limit or flow threshold of the aqueous residue is indicated by the instrument when this variation is zéro. The results obtained are shown in Table 5.
Time (min) Residue Flow Threshold (Pa)
without additive with polymer (Pl) with polymer (P2)
0 55 32 26
2 60 48 37
4 58 46 36
6 55 42 33
8 / 38 31
10 / 33 30
12 54 31 27
14 / 29 28
16 / / /
18 / / /
20 50 28 28
Table 5
Aqueous suspensions of aqueous copper ore residue with a solids content of 58%, with or without polymers (Pl) and (P2), are then prepared according to the invention. The characteristics of these suspensions are measured. The results obtained are shown in Table 6.
Residue
without additive with polymer (Pl) with polymer (P2)
% by weight dry/dry 0 0.1 0.1
PH 9.8 10.0 10.0
Conductivity in 2,160 2,770 2,820
Brookfield viscosity at 100 rpm (mPa.s) 2,196 838 824
Table 6
It can thus be seen that aqueous suspensions of reference copper residue with a solids content of 55%, 61% or 58% hâve high viscosities.
The addition of polymer (Pl) or of polymer (P2) according to the invention makes it 5 possible to significantly lower these viscosities as well as to control the flow threshold of these suspensions.
With the polymers according to the invention, it is therefore possible to disperse aqueous copper ore residues, in particular at the output of a thickener, which hâve high solids contents while controlling their rheology.

Claims (12)

1. A method for preparing an aqueous minerai suspension with a dry solids content that is greater than 40% by weight of the suspension and having at least one property chosen among:
- a Brookfield viscosity, measured at 100 rpm and at 25°C, of less than 1,800 mPa.s,
- a flow threshold, measured at a température of 25°C using a rheometer with imposed shearing, equipped with a bladed spindle, for a particular torsional loading, of less than 80 Pa and
- a Brookfield viscosity, measured at 100 rpm and at 25°C, of less than 1,800 mPa.s and a flow threshold, measured at a température of 25 °C using a rheometer with imposed shearing, equipped with a bladed spindle, for a particular torsional loading, of less than 80 Pa, comprising the addition, in an aqueous métal ore residue, of at least one polymer (P) with a molecular mass Mw, measured by GPC, ranging from 2,000 to 20,000 g/mol and prepared by at least one radical polymérisation reaction, at a température greater than 50°C, of at least one anionic monomer (M) comprising at least one polymerisable olefinic unsaturation and at least one carboxylic acid group or one of its salts, in the presence of at least one radical-generating compound chosen among hydrogen peroxide, benzoyl peroxide, acetyl peroxide, laurel peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, ammonium persulphate, an alkaline métal persulphate, preferably sodium persulphate or potassium persulphate, an azo compound such as 2,2'-azobis(2-(4,5-dihydroimidazolyl)propane, 2,2'-azobis(2-methylpropionamidine) dihydrochloride, diazo-valeronitrile, 4,4'-azobis-(4-cyanovaleric) acid, AZDN or 2,2'-azobisisobutyronitrile, and their respective combinations or associations with an ion chosen among Fe11, Fein, Cu1, Cu11 and mixtures thereof.
2. The method according to claim 1 in which the suspension has a viscosity of less than
1,500 mPa.s, preferably less than 1,200 mPa.s, more preferentially less than 1,000 mPa.s or less than 900 mPa.s, much more preferentially less than 800 mPa.s or less than
700 mPa.s, or even less than 500 mPa.s.
3. The method according to one of claims 1 or 2, in which the suspension has:
- a flow threshold of less than 70 Pa or less than 60 Pa, preferably less than 50 Pa or less than 40 Pa, more preferentially less than 30 Pa or less than 20 Pa or
- a flow threshold greater than 10 Pa, preferably greater than 12 Pa, more preferentially greater than 15 Pa or
- a flow threshold greater than 10 Pa, preferably greater than 12 Pa, more preferentially greater than 15 Pa and less than 70 Pa or less than 60 Pa, preferably less than 50 Pa or less than 40 Pa, more preferentially less than 30 Pa or less than 20 Pa.
4. The method according to one of claims 1 to 3 in which the suspension has a dry solids content greater than 50% by weight or 55% by weight, preferably greater than 60% by weight or greater than 65% by weight, more preferentially greater than 70% by weight or greater than 75% by weight.
5. The method according to one of claims 1 to 4 in which the suspension comprises from 0.01 to 2% by weight of polymer (P) (dry/dry relative to the ore residue), preferably from 0.01 to 1.8% or from 0.01 to 1.5%, more preferentially from 0.01 to 1.2% or from 0.01 to 1%, much more preferentially from 0.02 to 0.8% or from 0.03 to 0.5%, even more preferentially 0.04 to 0.25% or from 0.04 to 0.15%.
6. The method according to one of claims 1 to 5 comprising the addition of one, two or three different polymer(s) (P) or the fiirther addition of at least one compound chosen among a lignosulphonate dérivative, a silicate, an unmodifïed polysaccharide and a modified polysaccharide.
7. The method according to one of claims 1 to 6, in which:
the métal ore is chosen among lithium, strontium, lanthanide, actinide, uranium, rare earth, titanium, zirconium, vanadium, niobium, chromium, molybdenum, tungsten, manganèse, iron, cobalt, rhodium, iridium, nickel, palladium, platinum, copper, silver, gold, zinc, cadmium, tin and lead ores or • the métal ore comprises a métal oxide, a métal sulphide or a métal carbonate or • the métal ore residue comprises a residual amount of métal of less than 2,000 g per tonne (dry/dry) relative to the amount of métal ore residue; preferably an amount of métal ranging from 10 to 2,000 g per tonne (dry/dry) or from 10 to 1,000 g per tonne (dry/dry), relative to the amount of métal ore residue.
8. The method according to one of claims 1 to 7 in which the polymer (P) is added:
- before a step of pumping the aqueous métal ore residue, in particular using a pump chosen among a centrifugal pump, a peristaltic pump, a positive displacement pump, a compressed air pump, a diaphragm pump, a rotary pump or
- during a step of pumping the aqueous métal ore residue, in particular using a pump chosen among a centrifugal pump, a peristaltic pump, a positive displacement pump, a compressed air pump, a diaphragm pump, a rotary pump or
- after a step of pumping the aqueous métal ore residue, in particular using a pump chosen among a centrifugal pump, a peristaltic pump, a positive displacement pump, a compressed air pump, a diaphragm pump, a rotary pump or
- before a step of flocculation of the aqueous métal ore residue, for example using a polyacrylamide or a polyacrylamide dérivative or
- during a step of flocculation of the aqueous métal ore residue, for example using a polyacrylamide or a polyacrylamide dérivative or
- after a step of flocculation of the aqueous métal ore residue, for example using a polyacrylamide or a polyacrylamide dérivative or
- before a step of concentration of the aqueous métal ore residue, in particular by gravimétrie concentration, for example using at least one device chosen among a conventional thickener, a high-density thickener, a high-yield thickener, or by densimetric concentration, for example using at least one device chosen among a conventional thickener, a high-density thickener, a high-yield thickener, or by filtration, for example using at least one device chosen among a filter, a filter press, a rotary filter or
- during a step of concentration step the aqueous métal ore residue, in particular by gravimétrie concentration, for example using at least one device chosen among a conventional thickener, a high-density thickener, a high-yield thickener, or by densimetric concentration, for example using at least one device chosen among a conventional thickener, a high-density thickener, a high-yield thickener, or by filtration, for example using at least one device chosen among a filter, a filter press, a rotary filter or
- after a step of concentration of the aqueous métal ore residue, in particular by gravimétrie concentration, for example using at least one device chosen among a conventional thickener, a high-density thickener, a high-yield thickener, or by densimetric concentration, for example using at least one device chosen among a conventional thickener, a high-density thickener, a high-yield thickener, or by filtration, for example using at least one device chosen among a filter, a filter press, a rotary filter or
- before a step of conveying the aqueous métal ore residue, in particular conveying using an open pipe, a closed pipe or a pipeline or
- before a step of storing the aqueous métal ore residue or
- during a step of storing the aqueous métal ore residue.
9. The method according to one of claims 1 to 8, in which:
- the polymérisation reaction is also carried out in the presence of at least one compound comprising phosphorus in the oxidation I State, preferably a compound chosen among hypophosphorous acid (H3PO2) and a dérivative of hypophosphorous acid (H3PO2), preferably a compound comprising at least one hypophosphite ion (II2PO2), more preferentially a compound chosen among sodium hypophosphite (H2PO2Na), potassium hypophosphite (H2PO2K), calcium hypophosphite ([EhPChhCa) and mixtures thereof or
- the polymérisation reaction is carried out in the presence of at least one compound comprising phosphorus in the oxidation III State, preferably a compound chosen among phosphorous acid and a phosphorous acid dérivative, more preferentially a compound comprising at least one phosphite ion, in particular a compound chosen among sodium phosphite, calcium phosphite, potassium phosphite, ammonium phosphite, and combinations thereof or
- the polymérisation reaction is also carried out in the presence of at least one compound comprising a bisulphite ion, preferably a compound chosen among ammonium bisulphite, an alkaline métal bisulphite, in particular sodium bisulphite, potassium bisulphite, calcium bisulphite, magnésium bisulphite, and combinations thereof or
- the polymérisation reaction is also carried out in the presence of from 0.05 to 5% by weight, relative to the total amount of monomers, of at least one compound chosen among a xanthate dérivative, a mercaptan compound and a compound of formula (I):
R s F
XOOC/^S^'S/^COOX (I) wherein:
ο X independently represents H, Na or K and o R independently represents a Ci-C5-alkyl group, preferably a methyl group; particularly a compound of formula (I) which is disodic diisopropionate trithiocarbonate (DPTTC) or
- the polymérisation reaction is carried out at a température ranging from 50 to 98°C, preferably from 50 to 95°C or from 50 to 85°C or
- the polymérisation reaction is carried out in water, in a solvent, alone or in a mixture with water, particularly an alcoholic solvent, in particular isopropyl alcohol, preferably in water or
- the polymer (P) has a molecular mass Mw, measured by GPC, ranging from 2,200 to 10,000 g/mol, preferably from 2,400 to 9,500 g/mol or from 2,400 to 8,000 g/mol, more preferentially from 2,400 to 6,500 g/mol; or
- the polymer (P) is completely or partially neutralised, in particular at the end of the polymérisation reaction or
- the polymérisation reaction uses:
ο 100% by weight of anionic monomer (M) or o from 70% to 99.5% by weight of anionic monomer (M) and from 0.5% to 30% by weight of at least one other monomer.
10. The method according to one of claims 1 to 9 in which the anionic monomer (M) comprising at least one polymerisable olefinic unsaturation comprises one or two carboxylic acid groups, preferably comprises a single carboxylic acid group, preferably is chosen among acrylic acid, methacrylic acid, an acrylic acid sait, a methacrylic acid sait and mixtures thereof, more preferentially acrylic acid.
11. The method according to one of claims 1 to 10 in which the polymérisation reaction also uses at least one other monomer chosen among:
- another anionic monomer, preferably a monomer chosen among acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride and mixtures thereof, - 2-acrylamido-2-methylpropanesulphonic acid, a sait of 2-acrylamido-2methylpropanesulphonic acid, 2-(methacryloyloxy)ethanesulphonic acid, a sait of 2-(methacryloyloxy)ethanesulphonic acid, sodium methallyl sulphonate, styrene sulphonate and combinations or mixtures thereof,
- a non-ionic monomer comprising at least one polymerisable olefinic unsaturation, preferably at least one polymerisable ethylenic unsaturation and in particular a polymerisable vinyl group, more preferentially a non-ionic monomer chosen among styrene, vinyl caprolactam, the esters of an acid comprising at least one monocarboxylic acid group, in particular an ester of an acid chosen among acrylic acid, methacrylic acid and mixtures thereof, for example hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl méthacrylate, hydroxypropyl méthacrylate, alkyl acrylate, in particular Ci-Cio-alkyl acrylate, preferentially Ci-C4-alkyl acrylate, more preferentially methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, isobutyl acrylate, n-butyl acrylate, alkyl méthacrylate, in particular Ci-Cio-alkyl méthacrylate, preferentially Ci-C4-alkyl méthacrylate, more preferentially methyl méthacrylate, ethyl méthacrylate, n-propyl méthacrylate, isopropyl méthacrylate, isobutyl méthacrylate, n-butyl méthacrylate, aryl acrylate, preferably phenyl acrylate, benzyl acrylate, phenoxyethyl acrylate, aryl méthacrylate, preferably phenyl méthacrylate, benzyl méthacrylate, phenoxyethyl méthacrylate and
- a monomer of formula (II):
R1
(Π) wherein:
- R1 and R2, identical or different, independently represent H or CH3,
- L1 independently represents a group chosen among C(O), CH2, CH2-CH2 and O-CH2-CH2-CH2-CH2,
- L2 independently represents a group chosen among (CH2-CH2O)X, (CH2CH(CH3)O)y, (CH(CH3)CH2O)z and combinations thereof and
- x, y and z, identical or different, independently represent an integer or décimal comprised in a range from 0 to 150 and the sum of x+y+z is comprised in a range from 10 to 150.
12. An aqueous minerai suspension with a dry solids content that is greater than 50% by weight of the suspension and having at least one property chosen among:
- a Brookfîeld viscosity, measured at 100 rpm and at 25°C, of less than 1,800 mPa.s, - a flow threshold measured at a température of 25°C using a rheometer with imposed shearing, equipped with a bladed spindle, for a particular torsional loading, of less than 80 Pa and
- a Brookfîeld viscosity, measured at 100 rpm and at 25°C, of less than 1,800 mPa.s and a flow threshold, measured at a température of 25°C using a rheometer with imposed shearing, equipped with a bladed spindle, for a particular torsional loading, of less than 80 Pa, comprising an aqueous métal ore residue and at least one polymer (P) with a molecular mass Mw, measured by GPC, ranging from 2,000 to 20,000 g/mol and prepared by radical polymérisation reaction, at a température greater than 50°C, of at least one anionic monomer (M) comprising at least one polymerisable olefinic unsaturation and at least one carboxylic acid group or one of its salts, in the presence of at least one radical-generating compound chosen among hydrogen peroxide, benzoyl peroxide, acetyl peroxide, laurel peroxide, tert-butyl hydroperoxide, cumene hydroperoxide, ammonium persulphate, an alkaline métal persulphate, preferably sodium persulphate or potassium persulphate, an azo compound such as 2,2'-azobis(2-(4,5-dihydroimidazolyl)propane, 2,2'-azobis(2-methylpropionamidine) dihydrochloride, diazo-valeronitrile, 4,4'-azobis-(4-cyanovaleric) acid, AZDN or 2,2'-azobisisobutyronitrile, and their respective combinations or associations with an ion chosen among Fe11, Fein, Cu1, Cu11 and mixtures thereof.
OA1202000417 2018-06-08 2019-06-05 Controlling the rheology of a metal ore residue. OA19878A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
FR1854989 2018-06-08

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