EP4364852A1

EP4364852A1 - Collector composition and flotation method

Info

Publication number: EP4364852A1
Application number: EP22205668.1A
Authority: EP
Inventors: Mikhail GOLETS; Natalija Smolko Schwarzmayr; Henrik NORDBERG
Original assignee: Nouryon Chemicals International BV
Current assignee: Nouryon Chemicals International BV
Priority date: 2022-11-04
Filing date: 2022-11-04
Publication date: 2024-05-08
Also published as: WO2024094486A1

Abstract

The disclosure is directed to collector composition comprising anionic, cationic, and/or amphoteric derivatives of cashew nutshell liquid, and the use of those collector compositions in flotation methods.

Description

Field of the Invention

This invention relates a collector composition comprising anionic, cationic, and/or amphoteric derivatives of cashew nutshell liquid, and the use of those collector compositions in flotation methods.

Background

Froth flotation is a physico-chemical process used to separate mineral particles considered economically valuable from those considered waste. It is based on the ability of air bubbles to selectively attach to those particles that were previously rendered hydrophobic. The particle-bubble combinations then rise to the froth phase from where the flotation cell is discharged, whilst the hydrophilic particles remain in the flotation cell. Particle hydrophobicity is, in turn, induced by special chemicals called collectors. In direct flotation systems, it is the economically valuable minerals which are rendered hydrophobic by the action of the collector. Similarly, in reverse flotation systems, the collector renders hydrophobicity to those mineral particles considered waste. The efficiency of the separation process is quantified in terms of recovery and grade. Recovery refers to the percentage of valuable product contained in the ore that is removed into the concentrate stream after flotation. Grade refers to the percentage of the economically valuable product in the concentrate after flotation. A higher value of recovery or grade indicates a more efficient flotation system.
Considering the beneficiation of phosphate, the general requirement for fertilizer industry is the phosphate concentrate with P₂O₅ grade higher than 30% and recovery of >85-90%. The flotation of phosphate allows to reduce to minimal values the content of following gangue minerals: quartz, clay, feldspar, calcite, magnetite, dolomite etc. The applicable flotation method is affected by the nature of the phosphate ore.
The direct flotation is commonly applied for the igneous/magmatic apatite phosphate ores with generally low P₂O₅ feed grade (5-10%) and the valuable apatite phosphate concentrate is separated with the froth. Meanwhile, the reversed flotation is used for the sedimentary phosphate ores with generally higher P₂O₅ feed grade. In the latter case the impurities are separated from the phosphate concentrate with the froth whereas the valuable phosphate concentrate is resided in the cell tailings product. In some cases, the direct flotation can be also used to float phosphorous-containing minerals from sedimentary phosphates. Anionic collectors can be used in both mentioned cases: for the direct flotation of apatite/phosphate from igneous or sedimentary phosphate ores and for flotation of calcite, dolomite, and other carbonaceous impurities from sedimentary phosphate ores, respectively. The process of phosphate flotation generally includes following stages: ore classification, ore grinding, pulp conditioning with reagents and further flotation.
The flotation of slime impurities is commonly applied in the beneficiation processes of potash. Both anionic and nonionic collectors can be used in slime flotation, which is commonly performed prior to the flotation of potash. Further the direct flotation of KCI and NaCl is performed for sylvite and halite ores, respectively. Slimes are undesirable in KCI or NaCl flotation stages since they cause elevated consumption of potash collectors and decrease the purity of concentrate. Commonly, slimes contain 2/3 of clay minerals (dolomite, anhydrite, hematite, silica) and 1/3 clay (chlorite, Illite). The content of slimes in the flotation feed commonly varies between 1 and 6%. The process of potash slime flotation generally includes following stages: ore classification, ore grinding, pulp conditioning with reagents and further the flotation desliming.
WO 2019/007712 A1 and WO2019/007714 A1 , respectively, disclose a process to treat carbonatitic or siliceous non-sulfidic ores with a collector composition that comprises a phosphate compound of the formula:
wherein R is linear or branched, saturated or unsaturated hydrocarbon group containing 1 to 24 carbon atoms, A is an alkylene oxide unit; Y is H, Na, K or an ammonium or alkylated ammonium, n is 1 - 3, p is 0 - 25, X is chosen from the same groups as R-Ap or Y. These processes have been shown to provide the required grade of separation of the desired product from the ore and an improvement in recovery and selectivity.
A problem with the processes of WO 2019/007712 A1 and WO2019/007714 A1 however, is that they use synthetic non-renewable alcohols to prepare the collector compositions.
An alternative process for recovering phosphates from phosphate ores is described in RU2717862C1 . Here, a collector containing ethoxylated derivatives of cashew nutshell liquid (CNSL) having a degree of ethoxylation from 1 to 100 is used. Likewise, RU2744327C1 , discloses flotation desliming of potash ores using a collector containing propoxylated Cardanol (part of CNSL) having a degree of propoxylation from 10 to 70, or a mixture of propoxylated Cardanol and ethoxylated Cardanol having a degree of ethoxylation and propoxylation from 10 to 70.
There is a continued need for sustainable flotation systems that are more efficient in separating desired components and impurities.

Detailed Description

It has now been found that collector compositions comprising anionic, cationic, and/or amphoteric (i.e., charge-containing) derivatives of CNSL meet this need. Accordingly, in a first aspect, the present invention relates to a collector composition comprising:

(i) one or more compounds of formula (I):
wherein:
- R₁ is a saturated or unsaturated, linear C15 alkyl,
- R₂ is selected from H, -C(O)OH, -C(O)-Ap-OH, or -C(O)-Ap-O-Z, preferably H,
- -C(O)OH, or -C(O)-Ap-OH
- R₃ is selected from -OH, -O-Z, -Ap-OH, or -Ap-O-Z,
- R₄ is selected from H or -CH₃,
- R₅ is selected from H, -OH, -O-Z, -Ap-OH, or -Ap-O-Z,
- A is an alkylene oxide unit, preferably an ethylene oxide and/or propylene oxide unit, more preferably an ethylene oxide unit,
- p is 1 - 30, preferably 2-15, more preferably 3-12, and
- Z is an anionic moiety, a cationic moiety, or an amphoteric moiety,
- with the proviso that the compound of formula (I) comprises at least one Z group; and
(ii) optionally one or more surfactants.

The compounds of formula (I) are preferably derived from four components of cashew nutshell liquid (CNSL): anacardic acid [A], cardol [B], cardanol [C] and/or methylcardol [D]:
The R' group is typically a mixture of saturated, monoene, diene and triene linear C15 alkyls, such as (but not necessarily limited to):
CNSL is a common by-product produced by the cashew industry and is therefore a renewable and sustainable alternative to petrochemically derived alkylaromatic compounds. Natural cold extracted CNSL (C-CNSL) contains 60-75% anacardic acid, 15-25% cardol, 3-5% Cardanol and 1-2% methylcardol, respectively. In alternative, technical CNSL (T-CNSL) can be obtained by a heat extraction process where anacardic acid is converted to Cardanol. After removal of undesirable polymeric materials, T-CNSL generally contains >75% Cardanol and ~4-8% cardol. The production of T-CNSL has been practiced for decades.
It is therefore preferable for the one or more compounds of formula (I) to be anionic, cationic, or amphoteric derivatives of anacardic acid, cardol, cardanol and/or methylcardol, wherein the anacardic acid, cardol, cardanol and/or methylcardol are preferably obtained from CNSL.
More preferably, the one or more compounds of formula (I) are anionic, cationic, or amphoteric derivatives of cardanol, cardol and/or methylcardol, wherein the cardanol, cardol and/or methylcardol are preferably obtained from T-CNSL.
Accordingly, in a preferred embodiment, the collector composition comprises one or more compounds of formula (Ia):
wherein:

R₁ is a saturated or unsaturated, linear C15 alkyl,
R₃ is selected from OH, O-Z, Ap-OH, or Ap-O-Z,
R₄ is H or CH₃,
R₅ is selected from H, OH, O-Z, Ap-OH, or Ap-O-Z,
A is an alkylene oxide unit, preferably an ethylene oxide and/or propylene oxide unit, more preferably an ethylene oxide unit,
p is 1 - 30, preferably 2-15, more preferably 3-12, and
Z is an anionic moiety, a cationic moiety, or an amphoteric moiety,
with the proviso that the compound of formula (Ia) comprises at least one Z group.

More preferably, the collector composition comprises at least one compound of formula (Ib):
wherein:

R₁ is a saturated or unsaturated, linear C15 alkyl, and
R₃ is selected from O-Z or Ap-O-Z, preferably Ap-O-Z,
A is an alkylene oxide unit, preferably an ethylene oxide and/or propylene oxide unit, more preferably an ethylene oxide unit,
p is 1 - 30, preferably 2-15, more preferably 3-12, and
Z is an anionic moiety, a cationic moiety, or an amphoteric moiety.

Preferably, the compounds of formulae (I), (Ia) and/or (Ib) are anionic, cationic or amphoteric derivatives of anacardic acid, cardol, cardanol and methylcardol, wherein the anacardic acid, cardol, cardanol and methylcardol are obtained from CNSL and then derivatized to produce compounds of formulae (I), (Ia) and/or (lb). More preferably the compounds of formulae (I), (Ia) and/or (Ib) are anionic, cationic or amphoteric derivatives of cardanol, cardol and/or methylcardol, wherein the cardanol, cardol and/or methylcardol are obtained from T-CNSL and then derivatized to produce compounds of formulae (I), (Ia) and/or (lb). The anacardic acid, cardol, cardanol and/or methylcardol obtained from CNSL or T-CNSL may be directly derivatized as a mixture, or each component may be purified and derivatized separately.
Preferably still, the compounds of formulae (I), (Ia) and/or (Ib) are anionic or amphoteric derivatives of anacardic acid, cardol, cardanol and methylcardol, wherein the anacardic acid, cardol, cardanol and methylcardol are obtained from CNSL and then derivatized to produce compounds of formulae (I), (Ia) and/or (lb). More preferably the compounds of formulae (I), (Ia) and/or (Ib) are anionic or amphoteric derivatives of cardanol, cardol and/or methylcardol, wherein the cardanol, cardol and/or methylcardol are obtained from T-CNSL and then derivatized to produce compounds of formulae (I), (Ia) and/or (lb). The anacardic acid, cardol, cardanol and/or methylcardol obtained from CNSL or T-CNSL may be directly derivatized as a mixture, or each component may be purified and derivatized separately.
Preferably still, the compounds of formulae (I), (Ia) and/or (Ib) are anionic derivatives of anacardic acid, cardol, cardanol and methylcardol, wherein the anacardic acid, cardol, cardanol and methylcardol are obtained from CNSL and then derivatized to produce compounds of formulae (I), (Ia) and/or (lb). More preferably the compounds of formulae (I), (Ia) and/or (Ib) are anionic derivatives of cardanol, cardol and/or methylcardol, wherein the cardanol, cardol and/or methylcardol are obtained from T-CNSL and then derivatized to produce compounds of formulae (I), (Ia) and/or (lb). The anacardic acid, cardol, cardanol and/or methylcardol obtained from CNSL or T-CNSL may be directly derivatized as a mixture, or each component may be purified and derivatized separately.
The anionic, cationic, or amphoteric moiety Z of formulae (I), (Ia) and/or (Ib) preferably comprise or consist of a phosphate, a pyrophosphate, a polyphosphate, a phosphonate, a phosphinate, a sulfate, a sulfonate, a carboxylic acid, a sulfosuccinate, a sarcosinate, a polysulfate, a polysulfonate, a betaine, a sulfobetaine, an aminocarboxylate, an aminosulfonate, (alkyl)amines, (alkyl)diamines, etheramines, etherdiamines, esteramines, esterdiamines, and quaternary ammonium moieties.
Preferably, the cationic moieties Z comprise or consist of:

-(CH₂)_fNH₂ (optionally N-ethoxylated or in neutralized form);
-(CH₂)_fNH(CH₂)_fNH₂ (optionally N-ethoxylated or in neutralized form);
esteramines of the formula:
esterdiamines of the formula:

The cationic moiety Z may also comprise or consist of polyester polyamines (PEPA) and/or polyester polyquats (PEPQ). These are polymeric components containing multiple amine or quaternary ammonium centres, respectively. Commonly, PEPA and PEPQ are obtained from reaction of an amine, a dicarboxylic acid and a hydrophobic precursor (for example, fatty acid or fatty alcohol). In a preferred embodiment, the cationic moiety Z comprises or consists of a PEPA or PEPQ of the formula:
wherein:

R is a linear or branched, saturated or unsaturated, C2-C20 alkyl;
R₂ is either a link point to a compound of formulae (I), (la), or (Ib) (i.e., R₂-O-Z), or is a linear or branched, saturated or unsaturated, C1-C20 alkyl;
D is a halogen counterion (preferably Cl^-, I^-, Br^- or F^-) or an organic counterion (preferably sulfate, sulfonate, phosphate, phosphonate, carboxylate with C1-C10 alkyl);
p is 0 or 1;
n is 1 to 10;
R₃ and R₄ are each independently:
- For PEPA : H, or a linear or branched, saturated or unsaturated, substituted or unsubstituted C1-C20 alkyl (preferably CH₃ or CH₂CH₂OH),
- For PEPQ : a linear or branched, saturated or unsaturated, substituted or unsubstituted C1-C20 alkyl (preferably CH₃ or CH₂CH₂OH),
with the proviso that at least one R₂ is a link point to a compound of formulae (I), (Ia), or (Ib) (i.e., R₂-O-Z, which corresponds to an ester of a compound of formulae (I), (Ia) or (Ib) (R₂-O) with the PEPA/PEPQ moiety (Z)).

Preferably, Z of formulae (I), (Ia) and/or (Ib) comprises or consists of an anionic moiety or an amphoteric moiety, more preferably an anionic moiety.
Preferred amphoteric moieties Z comprise or consist of a betaine, a sulfobetaine, an aminocarboxylate, and/or an aminosulfonate.
Preferred anionic moieties Z comprise of consist of phosphates (cf. formula [E], below), sulfosuccinates (cf. formula [F], below), sarcosinates (cf. formula [G], below), maleates (cf. formula [H], below), amidocarboxylates (cf. formula [I], below), glycinates (cf. formula [J], below), taurates (cf. formula [K], below), hydroxamates (cf. formula [L], below), and/or sulfonates (cf. formula [N], below).
In a preferred embodiment, the anionic moiety Z of formulae (I), (Ia) and/or (Ib) comprises or consists of a phosphate of formula (II):
wherein:

n is 0 - 3, and
each X is independently selected from H, a cationic counterion (preferably an alkali(ne) metal cation, ammonium, or an alkyl ammonium), or Y; or when n is 2 or 3, the terminal O-X and a second O-X jointly may be a -O- bridge to give a cyclic phosphate,
wherein Y is a compound of formula (III),
wherein:
- R₆ is a saturated or unsaturated, linear C15 alkyl,
- R₇ is selected from H, -C(O)OH, or C(O)-Ap-OH,
- R₈ is selected from OH or Ap-OH,
- R₉ is selected from H or CH₃,
- R₁₀ is selected from H, OH, or Ap-OH,
- A is an alkylene oxide unit, preferably an ethylene oxide and/or propylene oxide unit, more preferably an ethylene oxide unit,
- p is 1 - 30, preferably 2-15, more preferably 3-12,
wherein at least of one of R₇, R₈ or R₁₀ contains an OH group that forms a phosphate ester link with the anionic moiety Z of formula (II),
with the proviso that at least one X of Formula (II) must be selected from H or a cationic counterion.

In a preferred embodiment, Y is a compound of formula (IIIa):
wherein:

R₆ is a saturated or unsaturated, linear C15 alkyl,
R₈ is selected from OH or Ap-OH,
R₉ is selected from H or CH₃,
R₁₀ is selected from H, OH, or Ap-OH,
A is an alkylene oxide unit, preferably an ethylene oxide and/or propylene oxide unit, more preferably an ethylene oxide unit,
p is 1 - 30, preferably 2-15, more preferably 3-12,
wherein at least of one of R₈ or R₁₀ contains an OH group that forms a phosphate ester link with the anionic moiety Z of formula (II).

In a particularly preferred embodiment, the collector composition comprises a mixture of two or more compounds of formulae [IA1], [IA2], [IA3] and/or [IA4]:

wherein:

R₁ is a saturated or unsaturated, linear C15 alkyl,
R₂ is selected from C(O)OH, C(O)-Ap-OH, or C(O)-Ap-O-Z, preferably C(O)OH or C(O)-Ap-OH,
R₃ is selected from OH, O-Z, Ap-OH, or Ap-O-Z,
R₅ is selected from OH, O-Z, Ap-OH, or Ap-O-Z,
A is an alkylene oxide unit, preferably an ethylene oxide and/or propylene oxide unit, more preferably an ethylene oxide unit,
p is 1 - 30, preferably 2-15, more preferably 3-12, and
Z is an anionic moiety, a cationic moiety, or an amphoteric moiety,
with the proviso that each compound of formulae [IA1], [IA2], [IA3] and [IA4] must each comprise at least one Z group.

Preferably, the collector composition comprises a mixture of compounds of formulae [IA2], [IA3] and [IA4], wherein the weight ratio of [IA3] to the sum of [IA2] and [IA4] (i.e., [IA3]: ([IA2]+[IA4])) is from about 75:25 to >99:1.
In a more preferred embodiment, the collector composition comprises at least one compound of the formula [IA3].
In a most preferred embodiment, the collector composition comprises at least one compound of formula [IB]:
wherein:

R' is a saturated or unsaturated, linear C15 alkyl,
A is an alkylene oxide unit, preferably an ethylene oxide unit,
p is 0 - 30, preferably 2-15, more preferably 3-12
n is 0 - 3, and
each X is independently selected from H, a cationic counterion (preferably an alkali(ne) metal cation, ammonium, or an alkyl ammonium), or Y; or when n is 2 or 3, the terminal O-X and a second O-X jointly may be a -O- bridge to give a cyclic phosphate, wherein Y is a compound of formula (IIIa),
wherein:
- R₆ is a saturated or unsaturated, linear C15 alkyl,
- R₈ is selected from OH or Ap-OH,
- R₉ is selected from H or CH₃,
- R₁₀ is selected from H, OH, or Ap-OH,
- A is an alkylene oxide unit, preferably an ethylene oxide and/or propylene oxide unit, more preferably an ethylene oxide unit,
- p is 1 - 30, preferably 2-15, more preferably 3-12,
wherein at least of one of R₈ or R₁₀ contains an OH group that forms a phosphate ester link with phosphate group of formula [IB],
with the proviso that at least one X must be selected from H or a cationic counterion.

The cationic counterion X may be any suitable cationic counterion that forms a stable phosphate salt. Preferred cationic counterions in that respect include, but are not limited to, Na, K, Ca, Mg, and ammonium cations of the formula NR_aR_bR_cR_d, wherein R_a, R_b, R_c and R_d are each independently selected from H or C1-C12 alkyl. Preferably, the cationic counterion is Na, K or NR_aR_bR_cR_d.
For the avoidance of doubt, the A unit as used herein is an alkylene oxide ether. Such alkoxylated products may be produced by procedures well-known in the art by reacting a free OH group with one or more alkylene oxides (e.g., ethylene oxide) in the presence of a suitable catalyst, e.g. a conventional basic catalyst, such as KOH, or a so-called narrow range catalyst (see e.g. Nonionic Surfactants: Organic Chemistry in Surfactant Science Series volume 72, 1998, pp 1-37 and 87-107, edited by Nico M. van Os; Marcel Dekker, Inc):
Finally, and again for the avoidance of any doubt, it should be understood that "p" in the "Ap" group corresponds to the number of moles of alkylene oxide that was added per mole of alcohol in the alkoxylation reaction. This is the commonly accepted and well understood meaning of this term, because the alkoxylation reaction normally produces a distribution of alkoxylated products (this can be observed, e.g., in WO 2021/140166 ). Thus, "p" is defined as the molar equivalents of alkylene oxide added per mole of alcohol in the alkoxylation reaction (this is also referred to as the "degree of alkoxylation"). For example, in the below worked example, 10 molar equivalents of ethylene oxide was reacted with the alcohol, hence in the below worked example "p" is 10 (i.e., the cardanol has a degree of ethoxylation of 10).

(ii) optional surfactants

In addition to the above compounds, the collector compositions of the present invention may comprise one or more surfactants. It should be understood, however, that the compounds described above may be successfully used in flotation methods without necessarily requiring an additional surfactant. For the avoidance of any doubt, it should be understood that the optional component (ii) of the collector composition disclosed herein is different to that of component (i),
The optional surfactant(s) (ii) is not particularly limited, and may be cationic, anionic, non-ionic, amphoteric, or a mixture of two or more of these. Below some examples are given, but these should only be considered as suitable for the invention and are not to be regarded as limiting.
Suitable amphoteric surfactants include, but are not limited to, those of the formula [C]:
wherein R₁ is a hydrocarbyl group with 8-22, preferably 12-18, carbon atoms; A is an alkyleneoxy group having 2-4, preferably 2, carbon atoms; p is a number 0 or 1; q is a number from 0 to 5, preferably 0; R₂ is a hydrocarbyl group having 1-4 carbon atoms, preferably 1, or R₂ is the group
wherein R₁, A, p and q have the same meaning as above; Y is selected from the group consisting of COO^- and SO₃ ^-, preferably COO^-; n is a number 1 or 2, preferably 1; M is a cation, which may be monovalent or divalent, and inorganic or organic, and r is a number 1 or 2. The amphoteric surfactant of formula [C] may also be used in its acid form, where the nitrogen is protonated and no external cation is needed. The compounds according to formula [C] can easily be produced in high yield from commercially available starting materials using known procedures. US 4,358,368 discloses some ways to produce the compounds where R₁ is a hydrocarbyl group with 8-22 carbon atoms (col 6, line 9 - col 7, line 52), and in US 4,828,687 (col 2, line 2 - col 2, line 31) compounds where R₂ is
attached to the compound of formula [C] via the methylene group, are described.
Further suitable amphoteric surfactants have the formula [D]:
wherein R₂ is a hydrocarbyl group with 8-22, preferably 12-18, carbon atoms, D is - CH₂- or - CH₂CH₂-, k is 0-4, preferably 0-3, and most preferably 0-2, and M is hydrogen or a cation, such as sodium or potassium. These products are well known and are produced commercially by methods well known in the art. The products where D is -CH₂- are prepared by the reaction between a fatty amine and chloroacetic acid or its salts, and the products where D is -CH₂CH₂-are prepared by the reaction between a fatty amine and acrylic acid or esters thereof, in the latter case the reaction is followed by hydrolysis.
Suitable anionic surfactants include, but are not limited to, fatty acids (such as those with an C8 to C22 acyl group), alkylphosphates, such as those of formula [E],

alkylsulfosuccinates, such as those of formula [F],
alkylsarcosinates, such as those of formula [G],
alkylmaleates, such as those of formula [H],
alkylamidocarboxylates, such as those of formula [I],
alkylglycinates, such as those of formula [J],
alkyltaurates, such as those of formula [K],
alkylhydroxamates, such as those of formula [L],
wherein for each of formulae [E]-[L]:
- R is linear or branched, saturated or unsaturated hydrocarbon group containing 1 to 24 carbon atoms;
- A is an alkylene oxide unit;
- Y is H, Na, K or an ammonium or alkylated ammonium;
- p is 0 - 25;
- X is chosen from the same groups as R-Ap or Y;
- m is 0-7;
- B is -H, -CH₃, - CH(CH₃)₂, -CH₂ CH(CH₃)₂, -CH(CH₃)CH₂CH₃;
- Z is -H, -CH₃ or -CH₂CH₃; and
- D is an alkaline metal counterion, preferably Na⁺, K⁺, Ca²⁺, or Mg²⁺.

Esters of the above alkylamidocarboxylates are also contemplated (preferably following the formula [I] of the alkylamidocarboxylates compounds, wherein Y is an alcohol derived hydrocarbon group, such as also described in US20160129456 ),
Further examples of suitable anionic surfactants include sulphonated fatty acids, alkylbenzensulphonates, such as those of formula [M],
and alkylsulfonates, such as those of formula [N],
wherein in formulae [M] and [N]:

R is linear or branched, saturated or unsaturated hydrocarbon group containing 1 to 24 carbon atoms; and
Y is H, Na, K or an ammonium or alkylated ammonium.

Suitable nonionic surfactants include alkoxylates (such as alkoxylated fatty alcohols RO(A)H, alkoxylated fatty acids RC(O)O(A)H), or alkyl glycosides (e.g., R(C₆O₆H₁₁)_k), or alkylethanolamides, such as those of the formulae [O] or [P],

wherein R is linear or branched, saturated or unsaturated hydrocarbon group containing 1 to 24 carbon atoms; A is an alkylene oxide unit; Y is H, Na, K or an ammonium or alkylated ammonium; Z is -H, -CH₃ or -CH₂CH_3; f is 1-25, preferably f is 1-15, and most preferable 1-10 and each f is independently 1 to 25; k is 1 or more, preferably about 1-5. Further suitable nonionic surfactants include ethoxylated and/or propoxylated derivatives of anacardic acid [A], cardol [B], cardanol [C] and/or methylcardol [D], preferably ethoxylated and/or propoxylated derivatives of cardol [B], cardanol [C] and/or methylcardol [D].
Suitable cationic surfactants include, but are not limited to, fatty amines (preferably C8-C22, linear or branched alkyamines), fatty diamines (preferably C8-C22, linear or branched), alkyl etheramines (preferably C8-C22, linear or branched alky etheramines), alkyl etherdiamines (preferably C8-C22, linear or branched alkyl etherdiamines), alkyl esteramines (preferably C8-C22, linear or branched alkyl esteramines), quaternary ammonium surfactants, polyester polyamines (PEPA), and polyester polyquats (PEPQ).
The terms PEPA or PEPQ are related to polymeric components containing multiple amine or quaternary ammonium centres, respectively. Commonly, PEPA and PEPQ are obtained from reaction of an amine, dicarboxylic acid and hydrophobic precursor (for example, fatty acid or fatty alcohol). Preferred PEPA and PEPQ cationic surfactants include, but are not limited to:
wherein:

R is a linear or branched, saturated or unsaturated, C2-C20 alkyl;
R₂ is a linear or branched, saturated or unsaturated, C1-C20 alkyl;
D is a halogen counterion (preferably Cl^-, I^-, Br^- or F^-) or an organic counterion (preferably sulfate, sulfonate, phosphate, phosphonate, carboxylate with C1-C10 alkyl);
p is 0 or 1;
n is 1 to 10;
R₃ and R₄ are each independently:
- For PEPA : H, or a linear or branched, saturated or unsaturated, substituted or unsubstituted C1-C20 alkyl (preferably CH₃ or CH₂CH₂OH),
- For PEPQ : a linear or branched, saturated or unsaturated, substituted or unsubstituted C1-C20 alkyl (preferably CH₃ or CH₂CH₂OH).

Further preferred PEPQ cationic surfactants include:
wherein:

R is a linear or branched, saturated or unsaturated, C1-C20 alkyl;
R' is H or C(O)R;
R" is -CH₂CH₂N(CH₃)₂CH₂CH₂-;
n is 1 to 10;
m is 0 to 2; and
k is 1 to 6.

Anionic and nonionic surfactants, such as those detailed above, are preferred. The collector composition disclosed herein may comprise a mixture of two or more anionic and/or nonionic surfactants.
For embodiments of the collector composition of the present disclosure that comprise one or more surfactants (ii), the weight ratio of component (ii) to component (i) in the collector composition is preferably from about 15:85 to 99:1, preferably about 20:80 to 98:2, preferably about 25:75 to 97:3.
Preferably, the collector composition of the present disclosure comprises component (i) and optional component (ii) in a total amount of about 15 wt.% to about 100 wt.% (relative to the total weight of the collector composition), preferably in the above weight ratio (ii) to (i).
The collector compositions described above may further comprise a solvent. Preferred solvents include, but are not limited to, water, isopropyl alcohol, propylene glycol, polyethylene glycol, diethylene glycol, hydrocarbon oils, C6-C18 alcohols, and mixtures thereof. If a solvent is used, then the collector composition preferably comprises at least 50 wt.%, more preferably at least 60 wt.%, more preferably at least 70wt.%, and most preferably at least 75 wt.% of the solvent (relative to the total weight of the collector composition).
In a second aspect, the present invention relates to a flotation method using the collector composition as described in detail above. The collector composition is suitable for treating non-sulfidic ores, such as phosphate-containing ores and/or ores comprising silicate minerals (preferably lithium and/or magnesium silicate minerals).
The collector composition of the present invention is particularly suitable for treating (1) apatite ores (direct flotation of apatite), (2) sedimentary phosphate ores (direct flotation of sedimentary phosphate rock or direct flotation of carbonate impurities - i.e., in the latter case, reversed flotation of sedimentary phosphate rock) and (3) potash ores (i.e., slime flotation from potash ores). The collector composition of the present invention is also particularly suitable for use in the dephosphorization of iron ore, silicates flotation from iron ore and silicates flotation from sedimentary phosphate ore.
It was found that the use of a collector composition comprising component (i) improved the P₂O₅ recovery and grade in the three abovementioned processes (1) direct flotation of apatite and (2) direct flotation of sedimentary phosphate rock and (3) reversed flotation of sedimentary phosphate rock (i.e. direct flotation of carbonate impurities from sedimentary phosphate). In addition, the use of a collector composition comprising component (i) improved the slime flotation from potash. In addition, CNSL components are not estrogenic materials and have better environmental profile comparing to the common nonylphenol ethoxylates if used in these applications. In addition, CNSL components are based on the renewable raw material source. Overall, the collector composition of the present disclosure provides numerous technical and environmental advantages over the previously known collector compositions.
For flotation of igneous or sedimentary phosphates, the collector composition may comprise component (i) only, or may comprise component (i) in combination with one or more surfactant (ii) (most common for this particular application would be a fatty acid). Advantageously, the simultaneous presence of compounds (i) and (ii) or so to say the balance between the two compounds allows to reach the optimal recovery and grade of P₂O₅. In a preferred embodiment "p" is between 0 and 30, more preferably 5 and 15, yet even more preferably between 8 and 12.
For the reversed phosphate flotation of sedimentary phosphate, the collector composition may comprise component (i) only, or may comprise component (i) in combination with one or more surfactants (ii) (most common for this particular application would be alkyl etheramines) and the balance between the two compounds allows to reach the optimal recovery and grade of P₂O₅ in the bottom concentrate product. In a preferred embodiment "p" is between 0 and 30, more preferably 2 and 10, yet even more preferably between 3 and 8.
For the slime flotation from potash, the collector composition may comprise component (i) only, or may comprise component (i) in combination with one or more surfactants (ii) (most common for this particular application would be alcohol ethoxylate phosphate ester, ethoxylated or propoxylated fatty alcohol, ethoxylated fatty amine, all C8-C22 linear or branched). By means of the novel component (i) slimes can be efficiently floated from the potash concentrate product, which stay in the flotation tails. In a preferred embodiment "p" is between 0 and 30, more preferably 2 and 10, yet even more preferably between 3 and 8.
The amount of collector composition added to the ore will in general be in the range of from about 10 to about 1000 g/ton dry ore, preferably in the range of from about 20 to about 500 g/ton dry ore, more preferably from about 100 to about 400 g/ton dry ore.
Other additives can be also involved in the flotation process together with the collector composition of the current invention. These reagents can be added either at the same time or, preferably, separately during the process and can include depressants, such as a polysaccharide, alkalized starch or dextrin, extender oils, frothers/froth regulators, such as pine oil, MIBC (methylisobutyl carbinol) and alcohols such as hexanol and alcohol ethoxylates/propoxylates, inorganic dispersants, such as silicate of sodium (water glass) and soda ash, and pH-regulators.
The process to treat ores according to the present disclosure preferably comprises the steps of:

conditioning of the mixture of a pulped mineral ore under stirring in aqueous solution.
adding a flotation depressant, flotation activator or flocculant to the mixture with further conditioning (optional).
adjusting the pH of the mixture with further conditioning (optional).
adding the collector composition of the invention with further conditioning.
adding a frother to the mixture with further conditioning (optional).
performing a froth flotation by introducing air into the mixture. The froth is skimmed off to recover targeted minerals.

It is noted that various elements of the present invention, including but not limited to preferred ranges for the various parameters, can be combined unless they are mutually exclusive.
The invention will be elucidated by the following examples without being limited thereto or thereby.

Examples

Example 1: Synthesis of phosphate ester of ethoxylated Cardanol

A sample of T-CNSL was obtained and was found to consist primarily of Cardanol (96. 2 wt-%), with minor amounts of Cardol (3.1 wt-%) and Methyl Cardol (0.7 wt-%) also being present.
T-CNSL (Cardanol, 425.0g, 1.41 moles, Mw = 301.0 eq/g) and KOH (3.0g of 45 % aq. solution) were charged to a Parr reactor (2L). The reactor was heated at 120ºC for 1.5h under N₂ sparge to reduce water content to 0.04 wt. %. The reactor was then heated to 130ºC and 622 g (14.12 moles) of ethylene oxide were fed gradually to not exceed the reactor pressure of 55 psig. After ethylene oxide addition was completed, the post-reaction was carried out for 1.5 hours at 130ºC until the pressure in the reactor stabilized. Then the reaction mixture was cooled to 80ºC and material was discharged.
Cardanol ethoxylate (T-CNSL+10EO) (1000 g, 1.35 moles, Mw = 741.5 g/mole) was placed into 2 L glass flask and heated at 60ºC for 1h under N₂ sparge. Then polyphosphoric acid (126.65 g, 1.06 moles) was added over a period of 0.5h, keeping the temperature of the reaction mixture at 65ºC. The reaction was carried out at 65ºC for additional 4h.
Then P₂O₅ (49.12 g, 0.346 moles, Mw = 142.0 g/mole) was added over 0.5h at 60-65ºC. Thereafter the temperature was increased to 75ºC and the reaction was carried out for 4h more. After the reaction was completed, 14.81g of deionized water was added and unreacted P₂O₅ and polyphosphoric acid were hydrolysed keeping the reaction mixture at 90ºC for 3h. Then the reaction was cooled to 75ºC and the product was discharged. Monoalkylphosphate:dialkylphosphate ratio of this compound was 4.1 (determined by ³¹P NMR).

Example 2: Flotation tests - Direct flotation of apatite

500 g of an igneous phosphate ore containing 42% apatite, 38% nepheline, 5% aegirine, 3% feldspar and 2% sphene was ground in a rod mill with 500 g of synthetic process water and 6.2 kg of stainless-steel rods (grinding to 70% -160µm - i.e. a granulometry of 70% through a 160 micron mesh). The ore/water slurry was transferred to a 1.3L cell of a flotation machine and conditioned with 200 g/t of sodium silicate solution (2 min) and 100 g/t of the collector blend (containing 40 wt% of tested component and 60 wt% of tall oil fatty acid) (1 min). The conditioning was performed at a rotor speed of 1000 min^-1.
The Rougher - Cleaner 1 - Cleaner 2 flotation set was performed during 4, 3 and 2 min, respectively (at a rotor speed 1000 min^-1 and an air flow of 3.0 L/min). Fractions coming from flotation were dried in the oven, weighed, and analyzed by means of XRF analysis. Recovery and Grade values were received.
Tested reagents:

Alkylphosphate ester with C16-C18 alkyl chain having a degree of ethoxylation of 4 (40 wt-%) and tall oil fatty acid sodium salt (60 wt-%) [comparative].
Alkylphosphate ester with C16-C18 alkyl chain having a degree of ethoxylation of 10 (40 wt-%) and tall oil fatty acid sodium salt (60 wt-%) [comparative].
Ethoxylate of Example 1 without phosphate ester (40 wt-%) and tall oil fatty acid sodium salt (60 wt-%) [comparative].
Phosphate ester of Example 1 (40 wt-%) and tall oil fatty acid sodium salt (60 wt-%) [inventive].

The results are shown in Figure 1. A surprising finding was that P₂O₅ recovery was improved by 3.5% and grade by 0.5% using phosphate ester of Example 1 compared to a phosphate ester based on a linear alcohol with 4 EO and with 10 EO (the linear alcohol-based phosphate esters are currently used in the industry).
Furthermore, the anionic Cardanol phosphate ester of Example 1 substantially outperformed the nonionic equivalent (cf. RU2717862C1 ) - P₂O₅ recovery was improved by 9.5% and the grade of P₂O₅ was 0.2% higher.
Figure 1. Improved recovery of apatite in direct flotation with anionic Cardanol ethoxylate phosphate ester (bottom points represent Rougher flotation, middle and top points represent Cleaner 1 and Cleaner 2, respectively).

Example 3: Flotation tests - direct flotation of carbonates from sedimentary phosphate

320 g of the sedimentary phosphate ore containing 19.0% P₂O₅ and 8.0% SiO₂ was used for flotation. The ore contained 37% of particles <74µm and 75% <215µm. The ore was transferred to a 1.3L cell of a flotation machine and filled up to the mark with water. The water used in flotation was a synthetic made process water that contain 600 ppm Ca²⁺ and 1600 ppm SO₄ ^2-. The ore slurry was conditioned with 7000 g/t H₃PO₄ (30 sec) and 1000 g/t of carbonate collector (2 min). After that the carbonate flotation was performed during 2 min. Further, the pH of the pulp was adjusted to 7 using 10% Na₂CO₃. 1000 g/t of isotridecyl alkylethermonoamine acetate was added to the pulp and conditioning was carried out for 1 min. At the next step the silicate flotation was performed (2 min). All flotation steps were performed at 800 min^-1 and 3.5 L/min air.
Fractions coming from flotation were dried in the oven, weighed, and analyzed by means of XRF analysis.
Tested reagents (carbonate flotation):

Nonionic Cardanol derivative having a degree of ethoxylation of 10 (comparative).
Anionic phosphate ester of Example 1 (inventive).

The results are shown in Table 1. The nonionic Cardanol ethoxylate resulted in no improvement in P₂O₅ grade after the flotation. Conversely, the anionic phosphate ester of Example 1 improved the P₂O₅ grade; the flotation of carbonates with the phosphate ester of ethoxylated Cardanol was more selective since the final grade of P₂O₅ was improved. Table 1. Improved performance in reversed flotation of sedimentary phosphate with Cardanol ethoxylate phosphate ester 10 EO.

Reagent P₂O₅ grade in the feed to flotation, % Final P₂O₅ grade of the tailings concentrate, %

Ethoxylated Cardanol 10EO 19.0 19.2

Phosphate ester of Example 1 19.4 21.5
In this specification, unless expressly otherwise indicated, the word 'or' is used in the sense of an operator that returns a true value when either or both of the stated conditions is met, as opposed to the operator 'exclusive or' which requires that only one of the conditions is met. The word 'comprising' is used in the sense of 'including' rather than to mean 'consisting of'. All prior teachings acknowledged above are hereby incorporated by reference. No acknowledgement of any prior published document herein should be taken to be an admission or representation that the teaching thereof was common general knowledge in Europe or elsewhere at the date hereof.

Claims

A collector composition comprising:
(i) one or more compounds of formula (I):
wherein:
R₁ is a saturated or unsaturated, linear C15 alkyl,

R₂ is selected from H, -C(O)OH, C(O)-Ap-OH, or C(O)-Ap-O-Z,

R₃ is selected from OH, O-Z, Ap-OH, or Ap-O-Z,

R₄ is selected from H or CH₃,

R₅ is selected from H, OH, O-Z, Ap-OH, or Ap-O-Z,

A is an alkylene oxide unit,

p is 1 - 30, and

Z is an anionic moiety, a cationic moiety, or an amphoteric moiety,

with the proviso that the compound of formula (I) comprises at least one Z group; and

(ii) optionally one or more surfactants.
The collector composition of claim 1, wherein the one or more compounds of formula (I) are selected from compounds of formula (Ia):
wherein:
R₁ is a saturated or unsaturated, linear C15 alkyl,

R₃ is selected from OH, O-Z, Ap-OH, or Ap-O-Z,

R₄ is H or CH₃,

R₅ is selected from H, OH, O-Z, Ap-OH, or Ap-O-Z,

A is an alkylene oxide unit,

p is 1 - 30, and

Z is an anionic moiety, a cationic moiety, or an amphoteric moiety,

with the proviso that the compound of formula (Ia) comprises at least one Z group.
The collector composition of claims 1 or 2, wherein the one or more compounds of formula (I) comprises at least one compound of formula (Ib):
wherein:
R₁ is a saturated or unsaturated, linear C15 alkyl, and

R₃ is selected from O-Z or Ap-O-Z,

A is an alkylene oxide unit,

p is 1 - 30, and

Z is an anionic moiety, a cationic moiety, or an amphoteric moiety.
The collector composition of any one of claims 1 to 3, wherein the anionic, cationic, or amphoteric moiety Z of formulae (I), (Ia) and/or (Ib) comprises or consists of a phosphate, a pyrophosphate, a polyphosphate, a phosphonate, a phosphinate, a sulfate, a sulfonate, a carboxylic acid, a sulfosuccinate, a sarcosinate, a glycinate, a polysulfate, a polysulfonate, a betaine, a sulfobetaine, an aminocarboxylate, an aminosulfonate, (alkyl)amines, (alkyl)diamines, etheramines, etherdiamines, esteramines, esterdiamines, and quaternary ammonium moieties.
The collector composition of any one of claims 1 to 4, wherein Z of formulae (I), (Ia) and/or (Ib) is an anionic moiety or an amphoteric moiety, preferably an anionic moiety.
The collector composition of claim 5, wherein anionic moiety Z of formulae (I), (Ia) and/or (Ib) comprises or consists of a phosphate of formula (II):
wherein:
n is 0 - 3, and

each X is independently selected from H, a cationic counterion (preferably an alkali(ne) metal cation, ammonium, or an alkyl ammonium), or Y; or when n is 2 or 3, the terminal O-X and a second O-X jointly may be a -O- bridge to give a cyclic phosphate,

wherein Y is a compound of formula (III),

wherein:
R₆ is a saturated or unsaturated, linear C15 alkyl,

R₇ is selected from H, -C(O)OH, or C(O)-Ap-OH,

R₈ is selected from OH or Ap-OH,

R₉ is selected from H or CH₃,

R₁₀ is selected from H, OH, or Ap-OH,

A is an alkylene oxide unit,

p is 1 - 30,

wherein at least of one of R₇, R₈ or R₁₀ contains an OH group that forms a phosphate ester link with the anionic moiety Z of formula (II),

with the proviso that at least one X of Formula (II) must be selected from H or a cationic counterion.
The collector composition of any one of claims 1 to 6, wherein the one or more compounds of formula (I) comprises at least one compound of formula [IB]:

wherein:
R' is a saturated or unsaturated, linear C15 alkyl,

A is an alkylene oxide unit,

p is 0 - 30,

n is 0 - 3, and

each X is independently selected from H, a cationic counterion (preferably an alkali(ne) metal cation, ammonium, or an alkyl ammonium), or Y; or when n is 2 or 3, the terminal O-X and a second O-X jointly may be a -O- bridge to give a cyclic phosphate,

wherein Y is a compound of formula (IIIa),

wherein:
R₆ is a saturated or unsaturated, linear C15 alkyl,

R₈ is selected from OH or Ap-OH,

R₉ is selected from H or CH₃,

R₁₀ is selected from H, OH, or Ap-OH,

A is an alkylene oxide unit, and

p is 1 - 30,

wherein at least of one of R₈ or R₁₀ contains an OH group that forms a phosphate ester link with phosphate group of formula [IB],

with the proviso that at least one X must be selected from H or a cationic counterion.
The collector composition of any one of claims 1 to 7, wherein the collector composition comprises one or more surfactants (ii) selected from cationic, anionic, non-ionic and/or amphoteric surfactants.
The collector composition of claim 8, wherein the collector composition comprises one of more surfactants (ii) selected from:
a) anionic surfactants selected from fatty acids, alkylphosphates, alkylsulfosuccinates, alkylsarcosinates, alkylglycinates, alkyltaurates, alkylmaleates, alkylamidocarboxylates and esters thereof, alkylhydroxamates, sulphonated fatty acids, alkylbenzensulphonates, or alkylsulfonates;

b) amphoteric surfactants selected from those of formula [C]:
wherein R₁ is a hydrocarbyl group with 8-22, preferably 12-18, carbon atoms; A is an alkyleneoxy group having 2-4, preferably 2, carbon atoms; p is a number 0 or 1; q is a number from 0 to 5, preferably 0; R₂ is a hydrocarbyl group having 1-4 carbon atoms, preferably 1, or R₂ is the group
wherein R₁, A, p and q have the same meaning as above; Y is selected from the group consisting of COO^- and SO₃ ^-, preferably COO^-; n is a number 1 or 2, preferably 1; M is a cation, which may be monovalent or divalent, and inorganic or organic, and r is a number 1 or 2;
or amphoteric surfactants selected from those of formula [D]:
wherein R₂ is a hydrocarbyl group with 8-22, preferably 12-18, carbon atoms, D is - CH₂- or -CH₂CH₂-, k is 0-4, preferably 0-3, and most preferably 0-2, and M is hydrogen or a cation, such as sodium or potassium

c) nonionic surfactants selected from alkoxylates, alkyl glycosides, or alkylethanolamides;

d) cationic surfactants selected from fatty amines, fatty diamines, alkyl etheramines, alkyl etherdiamines, alkyl esteramines, quaternary ammonium surfactants, polyester polyamines (PEPA), or polyester polyquats (PEPQ).
The collector composition of any one of claims 1 to 9, wherein the collector composition comprises one or more surfactants (ii), and wherein the weight ratio of component (ii) to component (i) in the collector composition is from about 15:85 to 99:1.
The collector composition of any one of claims 1 to 10, further comprising a solvent.
A flotation method comprising the use of a collector composition according to any one of claims 1 to 11.
The flotation method of claim 12, wherein the method is for the treatment of non-sulfidic ores.
The flotation method of claim 12, wherein the method is a flotation method to recover slime particles from potash salts
The flotation method of claim 12, wherein the method is for the dephosphorization of iron ore, silicates flotation from iron ore, or silicates flotation from sedimentary phosphate ore.