Composition Of Fatty Acids And N-Acyl Derivatives Of Sarcosine For The Improved Flotation Of Nonsulfide Minerals

Abstract

This invention relates to a collector composition for the direct froth flotation of nonsulfide ores comprising a) 50-99 wt.-% of a mixture of fatty acids and b) 1-50 wt.-% of an N-acyl derivative of sarcosine of the formula (I)

##STR00001## wherein R is a saturated or unsaturated hydrocarbon chain with 7 to 21 carbon atoms, wherein the mixture of comprises 10.0-35.0 wt.-% of fatty acid having a saturated C.sub.11 hydrocarbon group, 2.5-15.0 wt.-% of fatty acid having a saturated C.sub.13 hydrocarbon group, 10.0-25.0 wt.-% fatty acid having a monounsaturated C.sub.17 hydrocarbon group and 20.0-45.0 wt.-% fatty acid having a bisunsaturated C.sub.17 hydrocarbon group.

Claims

1. A collector composition for the direct froth flotation of nonsulfide ores comprising a) 50-99 wt.-% of a mixture of fatty acids and b) 1-50 wt.-% of an N-acyl derivative of sarcosine of the formula (I) ##STR00003## wherein R is a saturated or unsaturated hydrocarbon chain with 7 to 21 carbon atoms, wherein the mixture of comprises 10.0-35.0 wt.-% of fatty acid having a saturated C.sub.11 hydrocarbon group, 2.5-15.0 wt.-% of fatty acid having a saturated C.sub.13 hydrocarbon group, 10.0-25.0 wt.-% fatty acid having a monounsaturated C.sub.17 hydrocarbon group and 20.0-45.0 wt.-% fatty acid having a bisunsaturated C.sub.17 hydrocarbon group.

2. Composition according to claim 1, wherein the fatty acid mixture comprises fatty acids having 1.0-6.5 wt.-% of saturated C.sub.7 hydrocarbon chain 1.0-4.0 wt.-% of saturated C.sub.9 10.0-35.0 wt.-% of saturated C.sub.11 2.5-15.0 wt.-% of saturated C.sub.13 1.0-7.0 wt.-% of saturated C.sub.15 0.0-1.0 wt.-% of monounsaturated C.sub.15 0.0-1.0 wt.-% of bisunsaturated C.sub.15 0.5-2.0 wt.-% of saturated C.sub.17 10.0-25.0 wt.-% of monounsaturated C.sub.17 20.0-45.0 wt.-% bisunsaturated C.sub.17 0.0-2.0 wt.-% trisunsaturated C.sub.17 0.0-1.0 wt.-% saturated C.sub.19 0.0-4.0 wt.-% monounsaturated C.sub.19 0.0-7.0 wt.-% other fatty acids.

3. The composition of claim 1 and/or 2, wherein the component a) is a mixture of 0.3 to 1.7 weight parts of coconut oil fatty acid to 1 weight part of tall oil fatty acid.

4. The composition of one or more of claims 1 to 3, wherein the component b) is N-oleoylsarcosine.

5. The composition as claimed in one or more of claims 1 to 4, wherein the component a) is 80 wt.-% of a mixture of 1 weight part of coconut oil fatty acid and 1 weight part of tall oil fatty acid and component b) is 20 wt.-% of N-oleoylsarcosine.

6. A process for the direct froth flotation of nonsulfide minerals, the process comprising the steps of bringing the collector composition according to one or more of claims 1 to 5 in contact with an aqueous suspension of the nonsulfide mineral and frothing the so formed mineral pulp.

7. The process as claimed in claim 6, wherein the nonsulfide minerals is apatite.

8. The process as claimed in claim 6, wherein the nonsulfide minerals are selected from the group of calcite, scheelite, fluorspar, magnesite and barite.

9. The process as claimed in claim 6, wherein the nonsulfide mineral is ilmenite.

10. A direct froth flotation process according to claims 6 to 9, wherein the amount of collector composition added is an amount between 100 g and 1000 g per ton of ore.

11. Use of a composition according to one or more of claims 1 to 5 as collector for the direct flotation of non-sulfide ores in an amount between 100 and 1000 g per ton of ore.

Description

EXAMPLES

[0035] 1. General Procedure for Preparation of Collector Compositions According to this Invention:

[0036] Distilled coconut fatty acid sample was warmed to 35? C. until it was entirely melted and then added to tall oil fatty acid at room temperature. The fatty acid mixture was then homogenised by a slow stirring action. Finally, N-oleoylsarcosine was slowly added to the fatty acid mixture. The mixture was thereafter homogenised for a further 10 minutes. The procedure is completed when a clear, yellow-coloured liquid solution is obtained.

2. Collector Compositions According to this Invention Prepared Following Used the Procedure Describer Under 1.

Composition 1:

Component a:

[0037] 80 wt.-% of a mixture of 1 weight part of distilled coconut fatty acid and 1 weight part of tall oil fatty acid with a hydrocarbon chain distribution as follows: [0038] 3.25 wt.-% of saturated C.sub.7 hydrocarbon chain [0039] 2.85 wt.-% of saturated C.sub.9 [0040] 25.65 wt.-% of saturated C.sub.11 [0041] 8.60 wt.-% of saturated C.sub.13 [0042] 4.45 wt.-% of saturated C.sub.15 [0043] 0.02 wt.-% of monounsaturated C.sub.15 [0044] 0.20 wt.-% of bisunsaturated C.sub.15 [0045] 1.25 wt.-% of saturated C.sub.17 [0046] 19.10 wt.-% of monounsaturated C.sub.17 [0047] 28.5 wt.-% bisunsaturated C.sub.17 [0048] 0.60 wt.-% trisunsaturated C.sub.17 [0049] 0.05 wt.-% saturated C.sub.19 [0050] 1.25 wt.-% monounsaturated C.sub.19 [0051] 4.3 wt.-% others

Component b:

[0052] 20 wt.-% N-oleoylsarcosine

Composition 2:

Component a:

[0053] 80 wt.-% of a mixture of 0.33 weight part of distilled coconut fatty acid and 1 weight part of tall oil fatty acid with a hydrocarbon chain distribution as follows: [0054] 1.62 wt.-% of saturated C.sub.7 hydrocarbon chain [0055] 1.42 wt.-% of saturated C.sub.9 [0056] 12.82 wt.-% of saturated C.sub.11 [0057] 4.30 wt.-% of saturated C.sub.13 [0058] 2.37 wt.-% of saturated C.sub.15 [0059] 0.04 wt.-% of monounsaturated C.sub.15 [0060] 0.30 wt.-% of bisunsaturated C.sub.15 [0061] 1.17 wt.-% of saturated C.sub.17 [0062] 24.70 wt.-% of monounsaturated C.sub.17 [0063] 42.15 wt.-% bisunsaturated C.sub.17 [0064] 0.90 wt.-% trisunsaturated C.sub.17 [0065] 0.02 wt.-% saturated C.sub.19 [0066] 1.87 wt.-% monounsaturated C.sub.19 [0067] 6.40 wt.-% others

Component b:

[0068] 20 wt.-% N-oleoylsarcosine

Composition 3:

Component a:

[0069] 80 wt.-% of a mixture of 1.66 weight part of distilled coconut fatty acid and 1 weight part of tall oil fatty acid with a hydrocarbon chain distribution as follows: [0070] 4.10 wt.-% of saturated C.sub.7 hydrocarbon chain [0071] 3.59 wt.-% of saturated C.sub.9 [0072] 32.32 wt.-% of saturated C.sub.11 [0073] 10.84 wt.-% of saturated C.sub.13 [0074] 5.53 wt.-% of saturated C.sub.15 [0075] 0.02 wt.-% of monounsaturated C.sub.15 [0076] 0.15 wt.-% of bisunsaturated C.sub.15 [0077] 1.29 wt.-% of saturated C.sub.17 [0078] 16.19 wt.-% of monounsaturated C.sub.17 [0079] 21.40 wt.-% bisunsaturated C.sub.17 [0080] 0.44 wt.-% trisunsaturated C.sub.17 [0081] 0.06 wt.-% saturated C.sub.19 [0082] 0.92 wt.-% monounsaturated C.sub.19 [0083] 3.21 wt.-% others

Component b:

[0084] 20 wt.-% N-oleoylsarcosine

Composition 4:

Component a:

[0085] 67 wt.-% of a mixture of 1 weight part of distilled coconut fatty acid and 1 weight part of tall oil fatty acid with a hydrocarbon chain distribution as follows: [0086] 3.25 wt.-% of saturated C.sub.7 hydrocarbon chain [0087] 2.85 wt.-% of saturated C.sub.9 [0088] 25.65 wt.-% of saturated C.sub.11 [0089] 8.60 wt.-% of saturated C.sub.13 [0090] 4.45 wt.-% of saturated C.sub.15 [0091] 0.02 wt.-% of monounsaturated C.sub.15 [0092] 0.20 wt.-% of bisunsaturated C.sub.15 [0093] 1.25 wt.-% of saturated C.sub.17 [0094] 19.10 wt.-% of monounsaturated C.sub.17 [0095] 28.5 wt.-% bisunsaturated C.sub.15 [0096] 0.60 wt.-% trisunsaturated C.sub.17 [0097] 0.05 wt.-% saturated C.sub.19 [0098] 1.25 wt.-% monounsaturated C.sub.19 [0099] 4.3 wt.-% others

Component b:

[0100] 33 wt.-% N-oleoylsarcosine

Composition 5:

Component a:

[0101] 75 wt.-% of a mixture of 1 weight part of distilled coconut fatty acid and 1 weight part of tall oil fatty acid with a hydrocarbon chain distribution as follows: [0102] 3.25 wt.-% of saturated C.sub.7 hydrocarbon chain [0103] 2.85 wt.-% of saturated C.sub.9 [0104] 25.65 wt.-% of saturated C.sub.11 [0105] 8.60 wt.-% of saturated C.sub.13 [0106] 4.45 wt.-% of saturated C.sub.15 [0107] 0.02 wt.-% of monounsaturated C.sub.15 [0108] 0.20 wt.-% of bisunsaturated C.sub.15 [0109] 1.25 wt.-% of saturated C.sub.17 [0110] 19.10 wt.-% of monounsaturated C.sub.17 [0111] 28.5 wt.-% bisunsaturated C.sub.17 [0112] 0.60 wt.-% trisunsaturated C.sub.17 [0113] 0.05 wt.-% saturated C.sub.19 [0114] 1.25 wt.-% monounsaturated C.sub.19 [0115] 4.3 wt.-% others

Component b:

[0116] 25 wt.-% N-oleoylsarcosine

Composition 6:

Component a:

[0117] 84 wt.-% of a mixture of 1 weight part of distilled coconut fatty acid and 1 weight part of tall oil fatty acid with a hydrocarbon chain distribution as follows: [0118] 3.25 wt.-% of saturated C.sub.7 hydrocarbon chain [0119] 2.85 wt.-% of saturated C.sub.9 [0120] 25.65 wt.-% of saturated C.sub.11 [0121] 8.60 wt.-% of saturated C.sub.13 [0122] 4.45 wt.-% of saturated C.sub.15 [0123] 0.02 wt.-% of monounsaturated C.sub.15 [0124] 0.20 wt.-% of bisunsaturated C.sub.15 [0125] 1.25 wt.-% of saturated C.sub.17 [0126] 19.10 wt.-% of monounsaturated C.sub.17 [0127] 28.5 wt.-% bisunsaturated C.sub.17 [0128] 0.60 wt.-% trisunsaturated C.sub.17 [0129] 0.05 wt.-% saturated C.sub.19 [0130] 1.25 wt.-% monounsaturated C.sub.19 [0131] 4.3 wt.-% others

Component b:

[0132] 16 wt.-% N-oleoylsarcosine

3. Comparative Collector Compositions

Composition 7:

[0133] 80 wt.-% of tall oil fatty acid with a hydrocarbon chain distribution as follows: [0134] 0 wt.-% of saturated C.sub.7 hydrocarbon chain [0135] 0 wt.-% of saturated C.sub.9 [0136] 0 wt.-% of saturated C.sub.11 [0137] 0 wt.-% of saturated C.sub.13 [0138] 0.30 wt.-% of saturated C.sub.15 [0139] 0.05 wt.-% of monounsaturated C.sub.15 [0140] 0.40 wt.-% of bisunsaturated C.sub.15 [0141] 1.10 wt.-% of saturated C.sub.17 [0142] 30.30 wt.-% of monounsaturated C.sub.17 [0143] 55.80 wt.-% bisunsaturated C.sub.17 [0144] 1.20 wt.-% trisunsaturated C.sub.17 [0145] 0 wt.-% saturated C.sub.19 [0146] 2.50 wt.-% monounsaturated C.sub.19 [0147] 8.50 wt.-% others [0148] and [0149] 20 wt.-% N-oleoylsarcosine

Composition 8:

[0150] 80 wt.-% of distilled coconut fatty acid with a hydrocarbon chain distribution as follows: [0151] 6.50 wt.-% of saturated C.sub.7 hydrocarbon chain [0152] 5.70 wt.-% of saturated C.sub.9 [0153] 51.30 wt.-% of saturated C.sub.11 [0154] 17.20 wt.-% of saturated C.sub.13 [0155] 8.60 wt.-% of saturated C.sub.15 [0156] 0 wt.-% of monounsaturated C.sub.15 [0157] 0 wt.-% of bisunsaturated C.sub.15 [0158] 1.40 wt.-% of saturated C.sub.17 [0159] 7.90 wt.-% of monounsaturated C.sub.17 [0160] 1.20 wt.-% bisunsaturated C.sub.17 [0161] 0 wt.-% trisunsaturated C.sub.17 [0162] 0.10 wt.-% saturated C.sub.19 [0163] 0 wt.-% monounsaturated C.sub.19 [0164] 0.10 wt.-% others [0165] and [0166] 20 wt.-% N-oleoylsarcosine

Composition 9:

[0167] 100 wt.-% of tall oil fatty acid with a hydrocarbon chain distribution as follows: [0168] 0 wt.-% of saturated C.sub.7 hydrocarbon chain [0169] 0 wt.-% of saturated C.sub.9 [0170] 0 wt.-% of saturated C.sub.11 [0171] 0 wt.-% of saturated C.sub.13 [0172] 0.30 wt.-% of saturated C.sub.15 [0173] 0.05 wt.-% of monounsaturated C.sub.15 [0174] 0.40 wt.-% of bisunsaturated C.sub.15 [0175] 1.10 wt.-% of saturated C.sub.17 [0176] 30.30 wt.-% of monounsaturated C.sub.17 [0177] 55.80 wt.-% bisunsaturated C.sub.17 [0178] 1.20 wt.-% trisunsaturated C.sub.17 [0179] 0 wt.-% saturated C.sub.19 [0180] 2.50 wt.-% monounsaturated C.sub.19 [0181] 8.50 wt.-% others

Composition 10:

[0182] 100 wt.-% of a mixture of 1 weight part of distilled coconut fatty acid and 1 weight part of tall oil fatty acid with a hydrocarbon chain distribution as follows: [0183] 3.25 wt.-% of saturated C.sub.7 hydrocarbon chain [0184] 2.85 wt.-% of saturated C.sub.9 [0185] 25.65 wt.-% of saturated C.sub.11 [0186] 8.60 wt.-% of saturated C.sub.13 [0187] 4.45 wt.-% of saturated C.sub.15 [0188] 0.02 wt.-% of monounsaturated C.sub.15 [0189] 0.20 wt.-% of bisunsaturated C.sub.15 [0190] 1.25 wt.-% of saturated C.sub.17 [0191] 19.10 wt.-% of monounsaturated C.sub.17 [0192] 28.5 wt.-% bisunsaturated C.sub.17 [0193] 0.60 wt.-% trisunsaturated C.sub.17 [0194] 0.05 wt.-% saturated C.sub.19 [0195] 1.25 wt.-% monounsaturated C.sub.19 [0196] 4.3 wt.-% others

4. Flotation Test Results

Example I: Apatite Ore Containing 16.1% P.SUB.2.O.SUB.5., 47.9% SiO.SUB.2., 21.4% CaO, and 0.7% MgO

[0197] A 390 g portion of the ore sample was ground in a laboratory stainless steel mill for 5 minutes at 50 rpm and 66% solids. This resulted in the following particle size distribution for the flotation feed: P.sub.50=17 ?m and P.sub.80=47 ?m. On completion of the grinding stage, the milled slurry was transferred to a 2.5 L capacity flotation cell, where the percentage solid was adjusted to approximately 15% by addition of the appropriate amount of water. The flotation device was a Denver D-12 flotation machine and the impeller speed set to 1100 rpm. The flotation pulp was thereafter conditioned for 4 minutes and 3 minutes with the depressants sodium silicate (Na.sub.2SiO.sub.3, 550 g/t) and sodium carbonate (Na.sub.2CO.sub.3, 280 g/t) respectivelyin the indicated order. Next the collector mixture, which was freshly prepared as a 1% solution prior to starting each flotation test, was added and conditioned with the flotation pulp for 3 min. Finally, the air flow rate was set to 2 L/min and the resulting froth collected for 12 minutes.

TABLE-US-00001 Coconut Tall oil Collector oil fatty N-Oleoyl Grade Recovery com- fatty acid acid sarcosine Dosage P.sub.2O.sub.5 P.sub.2O.sub.5 position (wt.-%) (wt.-%) (wt.-%) (g/ton) (wt.-%) (wt.-%) 1 40 40 20 500 27.86 55.74 2 20 60 20 500 25.47 69.57 3 50 30 20 500 27.77 58.35 7 (C) 80 20 500 26.56 54.37 8 (C) 80 20 500 30.82 42.91

[0198] The results from the flotation tests show that the collector compositions according to this invention (1 to 3) show excellent flotation efficiency and in particular, notably improved mineral recovery in comparison with the reference compositions 7 and 8.

[0199] The P.sub.2O.sub.5 grade obtained with the inventive compositions is slightly lower than what was obtained especially with the reference 8 in the laboratory experiments. This difference in grade is considered negligible because industrial flotation plants typically put the rougher concentrate through two, three or even four cleaning steps. In this way, the grade of the final concentrate is typically increased.

Example II: Ilmenite Ore Containing on Approximately 32% TiO.SUB.2

[0200] Approximately 1.2 L of sample was collected from the flotation feed stream of an ilmenite flotation plant. The 1.2 L sample, which consisted of approximately 1785 g dry ore and 750 g water, was thereafter transferred to a 3.2 L capacity flotation cell. The collector was thereafter added as-is and conditioned for 10 minutes using a Denver D-12 flotation device with the impeller speed set at 1550 rpm. The percentage solids in the slurry was thereafter reduced from 71% to 51% by addition of 1.0 L of industrial water. Hereafter, the air flow rate was set to 8.5 L/min and resulting froth collected for 270 seconds. In the case of the ore in question, a fatty acid and paraffin was used as collector combination. The results are shown below.

TABLE-US-00002 Coconut oil Tall oil N-Oleoyl Collector Paraffin Grade Recovery Collector fatty acid fatty acid sarcosine dosage dosage TiO.sub.2 TiO.sub.2 composition (wt.-%) (wt.-%) (wt.-%) (g/ton) (g/ton) (wt.-%) (wt.-%) 1 40 40 20 840 360 37.4 81.1 9 (C) 100 840 360 36.8 76.0

[0201] The flotation results show that a 1:1 replacement of the fatty acid collector resulted in a 5.1% increase in recovery in combination with a marginal increase in concentrate grade.

Example III: Scheelite Ore Containing 0.20% WO.SUB.3

[0202] The ground ore was conditioned with the depressants tannin (25 g/t), sodium silicate (350 g/t) and sodium carbonate (1000 g/t) after which the slurry pH was adjusted to pH 10 by adding the required amount of NaOH solution. The collector was then added as-is and conditioned with the flotation slurry for 2 minutes followed by addition of Clariant frother Flotanol 7026 and conditioning for a further 1 minute. Hereafter sufficient water was added to decrease the percentage solids in the flotation cell from 60% during the conditioning step to 35% in the flotation step. The air flow rate was now set to 5 L/min and the resulting froth collected for 2 minutes.

TABLE-US-00003 Coconut Tall oil oil fatty fatty N-Oleoyl Grade Recovery Collector acid acid sarcosine Dosage W.sub.2O.sub.3 W.sub.2O.sub.3 composition (wt.-%) (wt.-%) (wt.-%) (g/ton) (wt.-%) (wt.-%) 4 33.5 33.5 33 145 1.16 78.3 5 37.5 37.5 25 194 0.81 84.2 6 42 42 16 151 1.61 78.0 10 (C) 50 50 195 1.42 72.7 9 (C) 100 184 0.87 71.3 9 (C) 100 369 0.72 78.2

[0203] The use of the new collector mixture resulted in a significant increase in WO.sub.3 grade as compared to the comparative product (100% tall oil fatty acid collector). In addition, a similar WO.sub.3 recovery value was obtained with 151 g/t dosage of the new collector blend as compared with 369 g/t dosage of the comparative tall oil fatty acid collector.