EP2355933B1 - Mixture of an amine alkoxylate ester and a quaternary ammonium compound as a collector for minerals containing silicate - Google Patents

Description

The present invention relates to the use of compositions of alkylammonium salts and amine alkoxylate esters in the flotation of silicate-containing minerals and ores.

In reverse flotation impurities are floated out of the value mineral. In particular, iron ore, calcium carbonate, phosphate and feldspar are often processed in this way. In many cases, siliceous minerals are the main constituents of these contaminants, causing quality degradation in the final product. These include quartz, mica and feldspar, as well as muscovite and biotite. For example, a high silicate content lowers the quality of iron ore concentrate, so that it is flotatively purified in Brazil, for example, by the use of alkyletheramines and alkylether diamines in order to be able to produce high-quality steels from the low-silicate concentrate.

Calcium carbonate is purified from silicate-containing and color-providing minerals with the aid of quaternary ammonium salts based on fatty acids or fatty alkylimidazoline compounds. Since calcium carbonate is used in addition to kaolin, rutile and talc as a white pigment in paper and plastic production, the highest possible whiteness or a low concentration of coloring minerals is desired. Due to the hardness of silicate, this would also lead to increased wear on the calenders of paper machines in papermaking. Therefore, calcium carbonate is purified in addition to dry processing via the flotation process.

In general, the aim is to reduce the silicate content, which in the case of calcium carbonate is often characterized as an acid-insoluble constituent, by less than 1.0% by weight due to the reverse flotation. The content of silicate in the task can vary and in some cases be from 10 to 20% by weight.

For example, fatty amines, alkyl ether amines, alkyl ether diamines or quaternary ammonium salt compounds are used as silicate collectors. These are also known under the trade name Flotigam ^®.
In WO-A-00/62937 discloses the use of quaternary ammonium salts for flotation of iron ore.
EP-A-0 876 222 describes the use of biodegradable esterquats as a collector for the flotation of non-sulphidic ores.
U.S. 4,995,965 discloses the use of hydroxypropylated quaternary ammonium salts, unsymmetrically substituted dimethyldialkylammonium salts, and dialkylhexahydropyrimidine compounds as the collector in the reverse flotation of calcium carbonate.
CA-A-1 187 212 discloses quaternary ammonium salts and bis-imidazolines as collectors in silicate flotation.

U.S. 5,720,873 and EP 1 949 964 A1 disclose a collector for silicate flotation comprising an amine alkoxylate in addition to a quaternary ammonium compound.

PAPINI RM ET AL: "Cationic flotation of iron ores: amine characterization and performance" MINERALS AND METALLURGICAL PROCESSING, CO, Vol. 18, No. 1, January 1, 2001 (2001-01-01), pages 5-9, ISSN : 0747-9182 discloses an overview of the cationic reverse flotation of iron ores.

However, the silicate flotation collectors described in the prior art show insufficient results in terms of selectivity and yield. The object of the present invention was therefore to provide an improved collector for the silicate flotation, which can be used in particular in the reverse flotation but also in the direct flotation.
Surprisingly, it has been found that a collector combination of an alkylammonium salt and an amine alkoxylate ester discharges less calcite fine grain than the previously described collector and collector combinations and thereby the recycling of valuable material is significantly improved, without thereby increasing the content of silicates in the concentrate.

1. A) mindestens einer quaternären Ammoniumverbindung, die mindestens einen, an das Ammoniumstickstoffatom gebundenen, gegebenenfalls Heteroatome enthaltenden, organischen Rest mit 8 bis 36 Kohlenstoffatomen enthält, und
2. B) mindestens einem Aminalkoxylatester der Formel (1) oder einem Salz davon
   
   worin

   A, B

   unabhängig voneinander ein C₂- bis C₅-Alkylenrest

   R¹

   ein C₈- bis C₂₄-Alkyl- oder Alkenylrest

   R², R³, R⁴

   unabhängig voneinander H oder ein C₈- bis C₂₄-Acylrest, mit der Maßgabe, dass mindestens einer der Reste R², R³ oder R⁴ für einen C₈- bis C₂₄-Acylrest steht

   x, y, z

   unabhängig voneinander eine ganze Zahl von 0 bis 50 mit der Maßgabe, dass x + y + z eine ganze Zahl von 1 bis 100 ist, bedeuten,

   in Mengen von 10 bis 5000 g/Tonne Erz als Sammler in der Silikatflotation.

The invention relates to the use of a composition

1. A) at least one quaternary ammonium compound containing at least one bound to the ammonium nitrogen, optionally containing heteroatoms, organic radical having 8 to 36 carbon atoms, and
2. B) at least one Aminalkoxylatester of formula (1) or a salt thereof
   
   wherein

   A, B

   independently of one another a C ₂ - to C ₅ -alkylene radical

   R ¹

   a C ₈ - to C ₂₄ -alkyl or alkenyl radical

   R ² , R ³ , R ⁴

   independently of one another H or a C ₈ - to C ₂₄ -acyl radical, with the proviso that at least one of the radicals R ² , R ³ or R ^{4 is} a C ₈ - to C ₂₄ -acyl radical

   x, y, z

   independently represent an integer from 0 to 50, with the proviso that x + y + z is an integer from 1 to 100,

   in quantities of 10 to 5000 g / ton of ore as a collector in silicate flotation.

Another object of the invention is a method for flotation of silicate-containing mineral by bringing a composition of A) and B) with the silicate-containing mineral in contact.

Another object of the invention is a composition containing 1 to 99 wt .-% of component A) and 1 to 99 wt .-% of component B).

The composition of A) and B) is also referred to below as a collector according to the invention.

worin

R⁶, R⁷

unabhängig voneinander C₁- bis C₆-Alkylgruppen oder Benzylgruppen,

R⁸, R⁹

unabhängig voneinander C₈- bis C₃₆-Alkylgruppen oder -Alkenylgruppen,
und

X

ein Anion bedeuten.

Preferably, the quaternary ammonium compound constituting component A) is a tetraalkylammonium salt of formula (2)

wherein

R ⁶ , R ⁷

independently of one another C ₁ - to C ₆ -alkyl groups or benzyl groups,

R ⁸ , R ⁹

independently of one another C ₈ - to C ₃₆ -alkyl groups or -alkenyl groups,
and

X

an anion.

worin

R¹⁰, R¹¹, R¹²

unabhängig voneinander H oder C₈- bis C₂₄-Acylgruppen,

R⁵

eine C₁- bis C₆-Alkylgruppe oder eine Benzylgruppe,

k, l, m

ganze Zahlen von 0 bis 5, und

X

ein Anion, vorzugsweise Cl oder CH₃SO₄, bedeuten.

Esterquats according to the formula (3) are further preferred embodiments of the quaternary ammonium compound according to constituent A),

wherein

R ¹⁰ , R ¹¹ , R ¹²

independently of one another H or C ₈ - to C ₂₄ -acyl groups,

R ⁵

a C ₁ to C ₆ alkyl group or a benzyl group,

k, l, m

integers from 0 to 5, and

X

an anion, preferably Cl or CH ₃ SO ₄ , mean.

R ¹ , R ⁸ and R ⁹ independently represent a linear or branched alkyl or alkenyl group. It is preferred that the radicals comprise 8 to 18 carbon atoms. Particularly preferred are 2-ethylhexyl, isononyl, isodecyl and Isotridecyl- and dodecyl radicals.

R ² , R ³ , R ⁴ , R ¹⁰ , R ¹¹ and R ¹² are acyl radicals having 8 to 24 carbon atoms. The acyl radicals preferably comprise 10 to 18 carbon atoms. They can be linear or branched. The acyl radicals can be saturated or unsaturated. Preferred acyl radicals are stearoyl and oleoyl radicals.

Component A) of the collector according to the invention contains at least one bound to the ammonium nitrogen, optionally heteroatom-containing organic radical having 8 to 36 carbon atoms. The radical may preferably be an alkyl, alkenyl or acyl radical, which is furthermore preferably designed as disclosed for R ¹ or R ² .

A especially either an ethylene - (- C ₂ H ₄ -), a propylene - (- C ₃ H ₆ -) or a butylene group (-C ₄ H ₈ -). Preferably, A is an ethylene group.

B is in particular either an ethylene - (- C ₂ H ₄ -), a propylene - (- C ₃ H ₆ -) or a butylene group (-C ₄ H ₈ -). Preferably, B is an isopropylene group.

k, l and m are preferably independently of one another 2, 3 or 4, in particular 3.

In the sum, x, y and z preferably give an integer of 15 to 30, in particular 20 to 25.

In a preferred embodiment, the amino ethoxylate ester constituting component B) is in the form of its mono- or di-ammonium salts obtained by neutralization with both organic and mineral acids.

The components A) and B) of the collector according to the invention can be used together with other collectors of the prior art, which are different from A) and B). Examples of such other collectors other than A) and B) are

R ¹⁴ -OR ¹³ -NH ₂ (II)

wherein R ^{14 is} a hydrocarbon group of 1 to 40, preferably 8 to 32 carbon atoms and R ^{13 is} an aliphatic hydrocarbon group of 2 to 4 carbon atoms;

R ¹⁷ -OR ¹⁵ -NH-R ¹⁶ -NH ₂ (III)

wherein R ¹⁷ is a hydrocarbon group having 1 to 40, preferably 8 to 32 carbon atoms, R ¹⁵ and R ¹⁶ correspond to one or various aliphatic hydrocarbon group having 2 to 4 carbon atoms;

(R ²¹ R ¹⁸ NR ¹⁹ R ²⁰ ) ^⊕ Y ^⊝ (IV)

wherein R ²¹ , R ¹⁸ , R ¹⁹ and R ²⁰ correspond to one or more hydrocarbon groups of 1 to 22 carbon atoms and Y ^{⊝ corresponds to} a suitable anion;

R ²² -NH ₂ (V)

wherein R ²² corresponds to a hydrocarbon group having 1 to 40, preferably 8 to 32 carbon atoms;

R ²³ -N- [D-NH ₂ ] ₂ (VI)

wherein R ^{23 is} a linear or branched alkyl group or alkenyl group having 6 to 24 carbon atoms and D is a C ₂ - to C ₄ alkylene group.

The use of the collector according to the invention can also be carried out in combination with foaming agents and pushers, as known from the prior art. In order to avoid that in the case of the silicate flotation of iron ore this is carried along, preferably hydrophilic polysaccharides, such as modified starch, carboxymethylcellulose, or gum arabic in dosages of 10 to 1000 g / ton are added as a pusher.

The silicate flotation is preferably carried out at a pH of 6 to 12, in particular 8 to 11, which is set, for example, with sodium hydroxide.

The use according to the invention can be carried out both in direct and in reverse silicate flotation. The use of the present invention is also useful in freeing silicate sand from impurities by flotatively separating the silicate sand from the contaminants using the compound of A) and B).

The preferred addition amount of the collector according to the invention is 100 to 1500 g / ton of ore, in particular 500 to 600 g / ton of ore.

The preferred weight ratio for the composition and use of the invention is A: B = 99: 1 to 1:99, especially 20:80 to 80:20.

Examples

The laboratory flotation experiments were carried out using a Denver flotation machine, type D 12 in a 2.5 L glass cell, whereby the pulp level was kept at the same level by constant addition of drinking water. The slurry contained 130 g of solid per liter.

Example 1: Ground calcite, 100% <250 microns, containing about 12 wt .-% silicate minerals, such as quartz, mica, and graphite, was transferred to a 2.5 L glass cell. The flotation pulp was then adjusted with drinking water to a level of 130 g solids per liter of pulp. The conditioning of the flotation pulp and the subsequent flotation was carried out with a DENVER flotation machine, type D-12.
For flotation of the graphite, the flotation pulp was first conditioned with 20 g / t of a pine oil. The pine oil was added undiluted to the pulp and conditioned for 1 min. The graphite was floated in the foam phase (graphite flotation). The flotation time was completed after 3 min.

The chamber product was then subjected to silicate flotation, whereby the silicates were swelled in the foam phase (Silikatflotationsberge). In the flotation cell remained the purified calcite (concentrate). The silicate collectors were added undiluted to the flotation pulp and left for 1 min. conditioned. The subsequent silicate flotation was complete after 4 min.

The flotation fractions (graphite flotation, Silikatflotationsberge and concentrate) were dehydrated, dried, weighed and dissolved in 25% HCl solution to determine the acid-insoluble portion. The acid-insoluble component (AIR) of the concentrate is a quality feature. The AIR content is calculated:% AIR = dried residue from the HCl solution / weighed into the HCl solution × 100%.

Another quality feature of the flotation concentrate is its whiteness, which was measured with a photometer against barite.

The collectors used and the resulting flotation results are shown in the following tables.

As a standard collector, dicocoalkyldimethylammonium chloride (standard collector 1), dioleoyloxyethyl-hydroxyethylmethylammonium methosulfate (standard collector 2) and tallow fatty propylenediamine with 40 moles of EO (standard collector 3) were used.

As an example of the collector according to the invention (collector 4) was a mixture of Dicocosalkyldimethylammoniumchlorid (standard collector 1, component A)) and ethoxylated Cocosalkylpropylenediamine, esterified with oleic acid (A = ethylene, R ¹ = Cocosfettalkyl, R ² , R ³ , R ⁴ = oleic acid , x, y, z in the sum 50, component B)) in different weight ratios It. Table 3 used. Table 1: Standard collector 1 = dicocoalkyldimethylammonium chloride Standard collector 2 = Dioleoyloxyethyl-hydroxyethylmethylammonium methosulfate example collector Addition [g / t] AIR [%] Spreading [%] 1 (V) 1 404 1.98 89.5 2 (V) 1 455 1.1 88.7 3 (V) 1 500 0.51 87.8 4 (V) 2 478 2.56 90.1 5 (V) 2 577 1.50 88.4 6 (V) 2 693 0.74 86.3 Standard collector 1 = dicocoalkyldimethylammonium chloride Standard collector 3 = tallow fat propylenediamine with 40 mol EO example collector Addition [g / t] collector Addition [g / t] AIR [%] Spreading [%] 7 (V) 1 500 3 0 0.51 87.8 8 (V) 1 250 3 250 0.83 86.1 9 (V) 1 350 3 150 0.52 87.2 10 (V) 1 450 3 50 0.52 88.3 11 (V) 1 0 3 500 1.32 84.5 Use of the collector 4 according to the invention example Ratio A): B) Addition [g / t] AIR [%] Spreading [%] 12 (V) 100: 0 500 0.51 87.8 13 80:20 500 0.50 91.4 14 70:30 500 0.51 89.8 15 50: 50 500 0.52 89.5 16 30: 70 500 0.49 89.1 17 (V) 0: 100 500 1.62 84.0 AIR = Acid Insoluble Rest

The results show that the standard collector results in a significantly lower Calcitausbringen compared to the collector according to the invention.

Claims (15)

1. The use of a composition of

   A) at least one quaternary ammonium compound which contains at least one organic radical having 8 to 36 carbon atoms that is bound to the ammonium nitrogen atom and possibly contains heteroatoms, and

   B) at least one amine alkoxylate ester of the formula (1) or a salt thereof

   

   where

   A, B independently of one another are a C₂ to C₅ alkylene radical

   R¹ is a C₈ to C₂₄ alkyl radical or C₈ to C₂₄ alkenyl radical

   R², R³, R⁴ independently of one another are H or a C₈ to C₂₄ acyl radical, with the proviso that at least one of the radicals R², R³ or R⁴ is a C₈ to C₂₄ acyl radical

   x, y, z independently of one another are an integer from 0 to 50 with the proviso that x + y + z is an integer from 1 to 100,

   in amounts of 10 to 5000 g/metric ton of ore as collector in silicate flotation.
2. The use as claimed in claim 1, wherein the ammonium salt A) is selected from tetraalkylammonium salts and esterquats.
3. The use as claimed in claim 2, wherein the tetraalkylammonium salt corresponds to the formula (2)

   

   where

   R⁶, R⁷ independently of one another are C₁ to C₆ alkyl groups or benzyl groups,

   R⁸, R⁹ independently of one another are C₈ to C₃₆ alkyl groups or C₈ to C₃₆ alkenyl groups
   and

   X is an anion.
4. The use as claimed in claim 2, wherein the esterquat corresponds to the formula (3)

   

   where

   R¹⁰, R¹¹, R¹² independently of one another are H or C₈ to C₂₄ acyl groups,

   R⁵ is a C₁ to C₆ alkyl group or a benzyl group,

   k, l, m independently of one another are integers from 0 to 5, and

   X is an anion, preferably Cl or CH₃SO₄.
5. The use as claimed in one or more of claims 1 to 4, wherein R¹, R², R³, R⁴, R⁸, R⁹, R¹⁰, R¹¹ and R¹² independently of one another are selected from linear or branched alkyl, alkenyl or acyl radicals having 8 to 18 carbon atoms.
6. The use as claimed in claim 5, wherein R¹, R², R³, R⁴, R⁸, R⁹, R¹⁰, R¹¹ and R¹² independently of one another are selected from 2-ethylhexane, isononane, isodecane, decane, dodecane or isotridecane radicals or the corresponding acyl radicals.
7. The use as claimed in one or more of claims 1 to 6, wherein A is an ethylene group (-C₂H₄-).
8. The use as claimed in one or more of claims 4 to 7, where k, l and m independently of one another are 2, 3 or 4.
9. The use as claimed in one or more of claims 1 to 8, where the sum of x, y and z gives an integer from 15 to 30.
10. The use as claimed in one or more of claims 1 to 9 for reverse flotation of silicate-containing minerals from iron ore, phosphate ore or calcium carbonate.
11. The use as claimed in one or more of claims 1 to 10 for purifying silicate sand.
12. The use as claimed in one or more of claims 1 to 11 in combination with frothers and depressants.
13. The use as claimed in one or more of claims 1 to 12 in a pH range of 7 to 12.
14. The use as claimed in one or more of claims 1 to 13 in amounts of 0.1 to 1.5 kg per metric ton of ore.
15. A composition containing

    A) at least one quaternary ammonium compound which contains at least one organic radical having 1 to 36 carbon atoms that is bound to the ammonium nitrogen atom and possibly contains heteroatoms, and

    B) at least one amine alkoxylate ester of the formula (1) or a salt thereof

    

    where

    A, B independently of one another are a C₂ to C₅ alkylene radical

    R¹ is a C₈ to C₂₄ alkyl radical or C₈ to C₂₄ alkenyl radical

    R², R³, R⁴ independently of one another are H or a C₈ to C₂₄ acyl radical, with the proviso that at least one of the radicals R², R³ or R⁴ is a C₈ to C₂₄ acyl radical

    x, y, z independently of one another are an integer from 0 to 50 with the proviso that x + y + z is an integer from 1 to 100,

    in the weight ratio of 99:1 to 1:99.