SEPARATION OF A MIXTURE USING MAGNETIC CARRIER PARTICLES

Abstract

The present invention relates to a process for separating at least one first material from a mixture comprising this at least one first material, at least one second material and at least one third material, which comprises at least the following steps: (A) providing a mixture comprising at least one first material, at least one second material, at least one third material and at least one hydrocarbon in an amount of more than 0.4% by weight, based on the sum of mixture, in the presence or 10 absence of at least one dispersion medium, (B) if appropriate, addition of at least one dispersion medium to the mixture obtained in step (A) in order to obtain a dispersion, (C) treatment of the dispersion from step (A) or (B) with at least one hydrophobic magnetic particle, so that the at least one first material and the at least one magnetic particle agglomerate, (D) separation of the adduct from step (C) from the mixture by application of a magnetic field, (E) if appropriate, dissociation of the adduct which has been separated off in step (D) in order to obtain the at least one first material and the at least one magnetic particle separately.

Claims

1.-11. (canceled)

12. A process for separating at least one first material from a mixture comprising this at least one first material, at least one second material and at least one third material, which comprises at least the following steps: (A) providing a mixture comprising at least one first material, at least one second material, at least one third material and at least one hydrocarbon in an amount of more than 0.4% by weight, based on the sum of mixture, in the presence or absence of at least one dispersion medium, (B) optionally, adding at least one dispersion medium to the mixture obtained in step (A) in order to obtain a dispersion, (C) treating the dispersion from step (A) or (B) with at least one hydrophobic magnetic particle, so that the at least one first material and the at least one magnetic particle agglomerate, (D) separating the adduct from step (C) from the mixture by application of a magnetic field, (E) optionally, dissociation of the adduct which has been separated off in step (D) in order to obtain the at least one first material and the at least one magnetic particle separately.

13. The process according to claim 12, wherein the at least one first material and the at least one second material are hydrophobic metal compounds and the at least one third material is a hydrophilic metal compound.

14. The process according to claim 12, wherein the at least one hydrocarbon is selected from the group consisting of crude oil derivatives, mineral oils, mineral waxes, vegetable oils, biodiesel, diesel and mixtures thereof.

15. The process according to claim 12, wherein the at least one hydrocarbon has a flash point of at least 20 C.

16. The process according to claim 12, wherein the at least one first material is a sulfidic molybdenum ore and the at least one second material is a sulfidic copper ore.

17. The process according to claim 12, wherein the at least one third material is selected from the group consisting of oxidic and hydroxidic metal compounds.

18. The process according to claim 12, wherein the at least one magnetic particle is selected from the group consisting of magnetic metals and mixtures thereof, ferromagnetic alloys of magnetic metals and mixtures thereof, magnetic iron oxides, cubic ferrites of the general formula (III)
M.sup.2+.sub.xFe.sup.2+.sub.1-xFe.sup.3+.sub.2O.sub.4(III) where M is selected from among Co, Ni, Mn, Zn and mixtures thereof and x is 1, hexagonal ferrites and mixtures thereof.

19. The process according to claim 12, wherein the dispersion medium in step (A) is water.

20. The process according to claim 12, wherein the mixture comprising at least one first material, at least one second material and at least one third material is milled to particles having a size of from 100 nm to 100 m before or during step (A).

21. The process according to claim 12, wherein the mixture of step (A) or, if step (B) is carried out, the dispersion obtained from step (B) is mixed vigorously such that energy in an amount of 150 kWh/m.sup.3 or more is introduced into the mixture prior to step (C).

22. The process according to claim 12, wherein a hydrophobizing agent is added in step (A).

Description

EXAMPLES

Example 1: Enriched Mo-Ore

[0152] In a buffled beaker 20 g of an enriched solid Mo-ore (19.5 g dry mass), containing 30.0% Mo as Molybdenite (MoS.sub.2) and 1.5% Cu mainly as Chalcopyrite (CuFeS.sub.2), are provided. The material has a particle size d80 of 30 m. The material was dispersed in 60 g of filtrated river water yielding a solid content of 25 w % (step 1).

[0153] To this dispersion 500 mg corresponding to a concentration of 25000 g/t solid of a liquid mixed hydrocarbon having a boiling range of 145-202 C. and a dynamic viscosity of 1.2.Math.10.sup.6 m.sup.2/sec (20 C.) were added (step 2). Afterwards this dispersion was vigorously mixed with an Ultra Turrax T25 stirrer for 10 min at 10000 rpm (spec. energy input approx. 600 kWh/m.sup.3) (Step 2a).

[0154] Subsequently to this slurry 0.6 g (3 w % with respect to the solid feed material) of a magnetite powder (Fe.sub.3O.sub.4, particle size: 50=1-3 m, 90=4-10 m) coated with 1.35 w % of a solid methyl silicone resin (melting range 35-55 C.) from a toluene solution according to WO 2015/110555 dispersed in 3.6 g of an 0.1 w % aqueous solution of a non-ionic surfactant (general formula RO(CH.sub.2CH.sub.2O).sub.xH, x8, derived from a C.sub.10 Guerbet alcohol ROH, wherein RC.sub.10H.sub.21) was added (step 3). This slurry was stirred for 15 min with a 30 mm pitch blade stirrer at 1400 rpm corresponding to an energy input of approx. 0.7 kWh/m.sup.3 (step 3a).

[0155] The resulting dispersion is pumped with a rate of 6 l/h to an Eriez L4 WHIMS lab-scale magnetic separator equipped with a 42 mm wedged wire matrix at a magnetic field strength of 0.7 T (step 4). After completion of the feed addition the matrix is flushed with water (step 4a). The combined dispersion and flush water are collected as tailings. Afterwards the magnetic field was switched off and the magnetic fraction containing the magnetite molybdenite agglomerates are flushed out from the matrix and collected separately yielding the magnetic concentrate. The elemental composition of both fractions was analyzed.

TABLE-US-00001 non-magnetic fraction magnetic fraction dry mass 8.28 g 11.65 g Cu-content 1.58% 1.10% Mo-content 5.08% 48.27% Cu-recovery 50.2% 49.8% Mo-recovery 7.0% 93.0%

Example 2: Enriched Mo-Ore

[0156] The experimental conditions were as in example 1 except that 100 mg (0.5%) of the liquid mixed hydrocarbon was used.

TABLE-US-00002 non-magnetic fraction magnetic fraction dry mass 15.73 g 3.88 g Cu-content 1.24% 1.68% Mo-content 30.51% 39.68% Cu-recovery 75.0% 25.0% Mo-recovery 75.7% 24.3%

Example 3: Enriched Mo-Ore

[0157] The experimental conditions were as in example 1 except that 200 mg (1.0%) of the liquid mixed hydrocarbon was used.

TABLE-US-00003 non-magnetic fraction magnetic fraction dry mass 14.94 g 4.89 g Cu-content 1.32% 1.38% Mo-content 27.75% 42.19% Cu-recovery 74.5% 25.5% Mo-recovery 66.8% 33.2%

Example 4: Enriched Mo-Ore

[0158] The experimental conditions were as in example 1 except that 300 mg (1.5%) of the liquid mixed hydrocarbon was used.

TABLE-US-00004 non-magnetic fraction magnetic fraction dry mass 11.63 g 8.08 g Cu-content 1.49% 1.12% Mo-content 18.68% 49.69% Cu-recovery 65.7% 34.3% Mo-recovery 35.1% 64.9%

Comparative Example 1: Enriched Mo-Ore

[0159] The experimental conditions were as in example 1 except that 80 mg (0.4%) of the liquid mixed hydrocarbon was used.

TABLE-US-00005 non-magnetic fraction magnetic fraction dry mass 16.14 g 3.66 g Cu-content 1.26% 1.73% Mo-content 29.85% 39.35% Cu-recovery 76.2% 23.8% Mo-recovery 77.0% 23.0%

Comparative Example 2: Enriched Mo-Ore

[0160] The experimental conditions were as in example 1 except that 60 mg (0.3%) of the liquid mixed hydrocarbon was used.

TABLE-US-00006 non-magnetic fraction magnetic fraction dry mass 16.88 g 2.65 g Cu-content 1.29% 1.76% Mo-content 26.22% 40.38% Cu-recovery 82.4% 17.6% Mo-recovery 82.2% 17.8%

[0161] Comparing examples 1 to 4 and comparative examples 1 and 2 show that in the case of the given Mo feed material the amount of added hydrocarbon strongly determines the Mo recovery in the inventive separation process and that with amounts of hydrocarbons above the one described in the art the separation process becomes more efficient.

Example 5: Enriched Mo-Ore

[0162] In a buffled beaker 20 g (19.3 g dry mass) of an enriched solid Mo-ore, containing 35.5% Mo as Molybdenite (MoS.sub.2) and 1.6% Cu mainly as Chalcopyrite (CuFeS.sub.2), are provided. The material has a particle size d80 of 40 m. The material was dispersed in 60 g of filtrated river water yielding a solid content of 25 w % (step 1). This dispersion was stirred with an Ultra Turrax T25 stirrer for 5 min at 10000 rpm (step 1 b).

[0163] To this dispersion 1.0 g corresponding to a concentration of 50000 g/t solid of the same liquid mixed hydrocarbon as used in example 1 (boiling range of 149-213 C., dynamic viscosity of 1.2.Math.10.sup.6 m.sup.2/sec (20 C.)) (step 2) and a slurry 0.6 g (3 w % with respect to the solid feed material) of a magnetite powder (the same as used in example 1) coated with 1.35 w % of a solid methyl silicone resin (melting range 35-55 C., the same as used in example 1) from a toluene solution according to WO 2015/110555 dispersed in 4 g isopropanol was added (step 3) were added thus, omitting the stirring step 2a.

[0164] This slurry was stirred for 15 min with a 30 mm pitch blade stirrer at 1400 rpm corresponding to an energy input of approx. 0.7 kWh/m.sup.3 at a specific power input of 3 kW/m.sup.3 (step 3a). The resulting dispersion is pumped with a rate of 6 l/h to an Eriez L4 WHIMS lab-scale magnetic separator equipped with a 42 mm wedged wire matrix at a magnetic field strength of 0.7 T (step 4). After completion of the feed addition the matrix is flushed with water (step 4a).

[0165] The combined dispersion and flush water are collected as tailings. Afterwards the magnetic field was switched off and the magnetic fraction containing the magnetite molybdenite agglomerates are flushed out from the matrix and collected separately yielding the magnetic concentrate. The elemental composition of both fractions was analyzed.

TABLE-US-00007 non-magnetic fraction magnetic fraction dry mass 7.55 g 12.37 g Cu-content 2.54% 1.49% Mo-content 23.07% 46.09% Cu-recovery 50.9% 49.1% Mo-recovery 23.4% 76.6%

Example 6: Enriched Mo-Ore

[0166] The experimental conditions were as in example 7 except that the stirring of the water and the liquid mixed hydrocarbon with the Ultra Turrax stirrer in step 1b was omitted.

[0167] Instead, after the addition of the liquid mixed hydrocarbon and before the addition of the magnetite carrier the mixture is vigorously stirred with an Ultra Turrax T25 for 5 min at 10000 rpm (spec. energy input approx. 300 kWh/m.sup.3 at a spec. power of 3600 kW/m.sup.3) (Step 2a).

TABLE-US-00008 non-magnetic fraction magnetic fraction dry mass 5.60 g 14.31 g Cu-content 4.08% 1.13% Mo-content 3.69% 51.03% Cu-recovery 58.5% 41.5% Mo-recovery 2.8% 97.2%

Example 7: Enriched Mo-Ore

[0168] In a buffled beaker 122.8 g of an enriched solid Mo-ore (120.0 g dry mass), containing 30.0% Mo as Molybdenite (MoS.sub.2) and 1.5% Cu mainly as Chalcopyrite (CuFeS.sub.2), are provided. The material has a particle size d80 of 30 m. The material was dispersed in 357 g of filtrated river water yielding a solid content of 25 w % (step 1) and mixed with an Ultra Turrax T50 stirrer for 5 min at 6000 rpm (spec. energy input approx. 150 kWh/m.sup.3). To this dispersion 3000 mg of the same liquid mixed hydrocarbon as used in example 1 (boiling range of 149-213 C., dynamic viscosity of 1.2 10.sup.6 m.sup.2/sec (20 C.)), corresponding to a concentration the hydrocarbon of 25000 g/t solid, were added (step 2). Afterwards this dispersion was vigorously mixed with an Ultra Turrax T50 stirrer for additional 2 min at 6000 rpm (spec. energy input approx. 50 kWh/m.sup.3) (Step 2a).

[0169] Subsequently to this slurry 3.6 g (3 w % with respect to the solid feed material) of magnetite powder (the same as in example 1) coated with 1.35 w % of the same solid methyl silicone resin as used in example 1 from a toluene solution according to WO 2015/110555 dispersed in 21.6 g of an 0.1 w % aqueous solution of the same non-ionic surfactant as used in example 1 was added (step 3).

[0170] This slurry was stirred for 15 min with a 45 mm pitch blade stirrer at 1000 rpm corresponding to an energy input of approx. 0.5 kWh/m.sup.3 (step 3a). The resulting dispersion is pumped with a rate of 6 l/h to an Eriez L4 WHIMS lab-scale magnetic separator equipped with a 42 mm wedged wire matrix at a magnetic field strength of 0.7 T (step 4). After completion of the feed addition the matrix is flushed with water (step 4a). The combined dispersion and flush water are collected as tailings which are filtered and dried. Afterwards the magnetic field was switched off and the magnetic fraction containing the magnetite molybdenite agglomerates are flushed out from the matrix and collected separately yielding the magnetic concentrate.

TABLE-US-00009 non-magnetic fraction magnetic fraction dry mass 48.75 g 74.80 g Cu-content 1.93% 0.99% Mo-content 5.76% 47.78% Cu-recovery 56.1% 43.9% Mo-recovery 7.3% 92.7%

[0171] The magnetic fraction of the magnetic separation of step 4 was filtered to obtain 84.15 g of wet filter cake with a water content of 11.1% and samples were taken for the corresponding elemental analyses. The elemental composition of both fractions was analyzed. For the recovery of the magnetite the remaining 16.88 g of the filtrated but not dried solid magnetic fraction (corresponds to 15.00 g dry mass) were suspended in a solution of 500 g of filtered river water and 1.35 g of the same non-ionic surfactant as used in step 3 (steps 5 and 5a) and stirred with a 72 mm pitch blade stirrer for 10 min at 300 rpm (corresponding to an energy input of approx. 0.04 kWh/m.sup.3) (step 5b).

[0172] Afterwards the resulting slurry is pumped to a lab-scale MIMS magnetic separator device as described in WO 2014/068142 (step 6) with a feed flow of 24.4 l/h a flush water flow of 12 l/h for the resulting magnetic fraction and a flow of 7.4 l/h for the magnetic fraction and a resulting flow of 29 l/h flow of the non-magnetic fraction. The resulting magnetic fraction which contained mainly the magnetite carrier material and the non-magnetic fraction containing the concentrated mineral target particles were filtered and their elemental composition was analyzed.

TABLE-US-00010 non-magnetic fraction magnetic fraction dry mass 0.71 g 14.30 g Cu-content 0.24% 0.99% Mo-content 4.23% 48.94% Cu-recovery 1.2% 98.8% Mo-recovery 0.4% 99.6%