High-selectivity flotation method for minerals

Abstract

The invention relates to a high-selectivity flotation method for minerals, belongs to a flotation technology, and aims to solve at least one of the problems of poor mineral collecting effect, poor selectivity, high collecting agent consumption and the like in the conventional flotation method. According to the method, firstly, impurities on the surface of ilmenite raw ore are stripped through first-time microwave pretreatment, meanwhile, part of Fe < 2 + > on the surface of the ilmenite is converted into Fe < 3 + >, and selective adsorption of a flotation reagent on the surface of the ore is better facilitated. The fucoidin is added into the ore pulp for secondary microwave pretreatment, so that the fucoidin in the ore pulp is broken to form an inhibitor with small molecular weight, and meanwhile, the reaction activity of the fucoidin is enhanced by microwave catalysis, so that the process of selectively adsorbing the fucoidin on the surface of gangue is more stable; the effect of improving the inhibition effect can be achieved, and the using amount of the collecting agent can be effectively reduced.

Description

Technical Field

[0001] The invention relates to the technical field of flotation, in particular to a high-selectivity flotation method for minerals. Background Art

[0002] my country has rich reserves of titanium resources, accounting for about 28% of the world's total reserves. Ilmenite is the main source of titanium resources in my country, mainly distributed in Panzhihua and Xichang areas of Sichuan. my country's ilmenite resources have the characteristics of "more poor ores, fewer rich ores, and fine particle size", making it difficult to achieve efficient sorting, restricting the further utilization of titanium resources. Flotation is an important method for achieving efficient sorting of fine-grained mineral resources. Due to the similar surface properties of the target minerals and gangue minerals, traditional fatty acid collectors have good collection properties, but it is difficult to achieve efficient separation of the two. Arsonic acid and phosphoric acid collectors have certain collectors and selectivities, but there are problems such as environmental pollution. Therefore, it is necessary to develop environmentally friendly and highly selective flotation collectors.

[0003] In recent years, hydroxamic acid collectors have attracted extensive attention in ilmenite flotation processes due to their excellent flotation performance. However, the collectivity and selectivity of hydroxamic acid collectors containing only one functional group are still insufficient, making it difficult to achieve selective separation of ilmenite and gangue minerals. Summary of the invention

[0004] In view of the above analysis, the present invention aims to provide a highly selective flotation method for minerals to solve at least one of the problems of poor mineral collection effect, poor selectivity, and high amount of collector used in the existing one-rough-one-fine flotation method.

[0005] In a first aspect, the present invention provides a high-selectivity flotation method for minerals, comprising the following steps: subjecting a raw ore pulp to a first microwave pretreatment, adding fucoidan and subjecting it to a second microwave pretreatment, adding a collector and subjecting it to a first flotation to obtain a coarse concentrate, subjecting the coarse concentrate to a second flotation to obtain an ilmenite concentrate;

[0006] The chemical structural formula of the collector is shown in formula (I):

[0007]

[0008] Wherein, R is an alkyl group.

[0009] Furthermore, the microwave power of the first microwave pretreatment is 400-800 W, and the treatment time is 1-5 min. The microwave power of the second microwave pretreatment is 700-1000 W, and the treatment time is 3-8 min.

[0010] Furthermore, sulfuric acid is added during the first flotation and the second flotation. Preferably, sulfuric acid is added during the first flotation to make the pulp pH = 4-5, and sulfuric acid is added during the second flotation to make the pulp pH = 3-4.

[0011] Furthermore, the added amount of fucoidan is 100-300 g / t.

[0012] Furthermore, the collector is prepared by the following method:

[0013] (1) dissolving an ester compound and a catalyst in a dispersant, and then adding an aldehyde to carry out a substitution reaction to obtain an ester compound with a branched chain;

[0014] (2) dissolving the hydroxylamine salt and the alkali in methanol, dispersing and dissolving them by ultrasonication, mixing them and reacting them in an ice-water bath, adding the branched ester compound, heating them for hydroxyoximation reaction, adjusting the pH, filtering them, and drying them to obtain the collector.

[0015] Furthermore, in step (1), the ester compound is dimethyl malonate or diethyl malonate;

[0016] The catalyst is one of 1-butyl-3-methylimidazole, N-butylpyridine nitrate, 1-hexyl-3-methylimidazole hexafluorophosphate, and 1-hexyl-3-methylimidazole hexafluorophosphate;

[0017] The dispersant is methanol or ethanol;

[0018] The aldehyde is one of octanal and decanal.

[0019] Furthermore, in step (1), the molar ratio of the ester compound, the aldehyde and the catalyst is 1:1 to 1.1:0.4.

[0020] Furthermore, in step (2), the hydroxylamine salt is one of hydroxylamine hydrochloride, hydroxylamine carbonate or hydroxylamine sulfate.

[0021] Furthermore, in step (2), the heating temperature is 30 to 60°C.

[0022] Furthermore, in step (2), the molar ratio of the branched ester compound, the hydroxylamine salt and the base is 1:2.2-2.3:4.4-4.5.

[0023] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0024] (1) In the present invention, the first microwave pretreatment is used to remove impurities on the surface of the ilmenite ore, and at the same time, part of the Fe 2+ Converted to Fe 3+, which is more conducive to the selective adsorption of flotation reagents on the mineral surface. After adding fucoidan to the slurry and performing a second microwave pretreatment, the fucoidan in the slurry can be broken to form small molecular weight inhibitors. At the same time, microwave catalysis enhances the reaction activity of fucoidan. Therefore, the process of fucoidan selectively adsorbing on the surface of gangue is more stable, which can not only improve the inhibitory effect, but also effectively reduce the amount of collector used.

[0025] (2) The present invention combines an olefin-based bifunctional collector with strong selectivity, the polar groups of the collector are all hydroxyoxime groups, and the non-polar group contains a double bond, one of the hydroxyoxime groups can first combine with the active site on the surface of ilmenite to form a stable chelate ring, and the other hydroxyoxime group can not only rotate flexibly, but also reduce the inductive effect between the two polar groups. In addition, the double bond in the non-polar group can adjust the charge distribution and electron cloud density of the polar group, thereby effectively improving the reaction performance of the polar group with metal ions, enhancing the selectivity of the collector molecule, improving the concentrate grade and recovery rate, and reducing the amount of collector used.

[0026] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be achieved and obtained through the contents particularly pointed out in the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings are only for the purpose of illustrating particular embodiments and are not to be considered limiting of the present invention. Like reference symbols denote like components throughout the drawings.

[0028] Figure 1 This is the infrared spectrum of the collector prepared in Example 1 of the present invention;

[0029] Figure 2 The mass spectrum of the collector prepared in Example 1 of the present invention;

[0030] Figure 3 This is the nuclear magnetic resonance image of the collector prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0031] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0032] A specific embodiment of the present invention discloses a high-selectivity flotation method for minerals, comprising the following steps: subjecting the raw ore pulp to a first microwave pretreatment, adding fucoidan and subjecting it to a second microwave pretreatment, adding a collector and subjecting it to a first flotation to obtain a coarse concentrate, subjecting the coarse concentrate to a second flotation to obtain an ilmenite concentrate;

[0033] The chemical structural formula of the collector is shown in formula (I):

[0034]

[0035]

[0036] Wherein, R is an alkyl group.

[0037] Compared with the prior art, the present invention firstly adopts the first microwave pretreatment to remove the impurities on the surface of the ilmenite ore, and at the same time removes part of the Fe 2+ Converted to Fe 3+ , which is more conducive to the selective adsorption of flotation agents on the mineral surface. After adding fucoidan to the slurry and performing a second microwave pretreatment, the fucoidan in the slurry can be broken to form small molecular weight inhibitors. At the same time, microwave catalysis enhances the reaction activity of fucoidan. Therefore, the process of selective adsorption of fucoidan on the surface of gangue is more stable, which can not only improve the inhibitory effect, but also effectively reduce the amount of collector.

[0038] In addition, the present invention combines an olefin-based bifunctional collector with strong selectivity, the polar groups of the collector are all hydroxyoxime groups, and the non-polar group contains a double bond, one of the hydroxyoxime groups can first combine with the active site on the surface of ilmenite to form a stable chelate ring, and the other hydroxyoxime group can not only rotate flexibly, but also reduce the inductive effect between the two polar groups. In addition, the double bond in the non-polar group can adjust the charge distribution and electron cloud density of the polar group, thereby effectively improving the reaction performance of the polar group with metal ions, enhancing the selectivity of the collector molecule, improving the concentrate grade and recovery rate, and can reduce the amount of collector used.

[0039] In a specific embodiment, the mass concentration of the raw ore slurry is 30-40%.

[0040] It should be noted that the raw ore slurry refers to the ilmenite ore added into water.

[0041] Specifically, the raw ore described in the present invention is calcium-magnesium-rich ilmenite, the gangue minerals are forsterite and titanopyroxene, and the TiO2 grade in the raw ore is ≤15%.

[0042] In a specific embodiment, the microwave power of the first microwave pretreatment is 400-800 W, for example, 400 W, 420 W, 440 W, 460 W, 480 W, 500 W, 520 W, 540 W, 560 W, 580 W, 600 W, 620 W, 640 W, 660 W, 680 W, 700 W, 720 W, 740 W, 760 W, 780 W, 800 W, and the treatment time is 1-5 min, for example, 1 min, 1.5 min, 2 min, 2.5 min, 3 min, 3.5 min, 4 min, The microwave power of the second microwave pretreatment is 700-1000 W, for example, 700 W, 720 W, 740 W, 760 W, 780 W, 800 W, 820 W, 840 W, 860 W, 88 W, 900 W, 920 W, 940 W, 960 W, 980 W, 1000 W, and the treatment time is 3-8 min, for example, 3 min, 3.5 min, 4 min, 4.5 min, 5 min, 5.5 min, 6 min, 6.5 min, 7 min, 7.5 min, 8 min.

[0043] In a specific embodiment, sulfuric acid is also added during the first flotation and the second flotation.

[0044] Preferably, sulfuric acid is added during the first flotation to make the pulp pH = 4-5, and sulfuric acid is added during the second flotation to make the pulp pH = 3-4.

[0045] Preferably, a collector solution is added during the first flotation.

[0046] Specifically, the two flotation times are the same.

[0047] In a specific embodiment, the amount of fucoidan added is 100-300g / t, for example, 100g / t, 120g / t, 140g / t, 160g / t, 180g / t, 200g / t, 220g / t, 240g / t, 260g / t, 280g / t, 300g / t, and the amount of collector added is 500-800g / t, 520g / t, 540g / t, 560g / t, 580g / t, 600g / t, 620g / t, 640g / t, 660g / t, 680g / t, 700g / t, 720g / t, 740g / t, 760g / t, 780g / t, 800g / t.

[0048] In a specific embodiment, the collector is prepared by the following method:

[0049] (1) dissolving an ester compound and a catalyst in a dispersant, and then adding an aldehyde to carry out a substitution reaction to obtain an ester compound with a branched chain;

[0050] (2) dissolving the hydroxylamine salt and the alkali in methanol, dispersing and dissolving them by ultrasonication, mixing them and reacting them in an ice-water bath, adding the branched ester compound, heating them for hydroxyoximation reaction, adjusting the pH, filtering them, and drying them to obtain the collector.

[0051] In a specific embodiment, in step (1), the ester compound is dimethyl malonate or diethyl malonate;

[0052] The catalyst is one of 1-butyl-3-methylimidazole, N-butylpyridine nitrate, 1-hexyl-3-methylimidazole hexafluorophosphate, and 1-hexyl-3-methylimidazole hexafluorophosphate;

[0053] The dispersant is methanol or ethanol;

[0054] The aldehyde is one of octanal and decanal.

[0055] In a specific embodiment, in step (1), the molar ratio of the ester compound, the aldehyde and the catalyst is 1:1 to 1.1:0.4.

[0056] In a specific embodiment, in step (2), the hydroxylamine salt is one of hydroxylamine hydrochloride, hydroxylamine carbonate or hydroxylamine sulfate.

[0057] In a specific embodiment, in step (2), the heating temperature is 30-60°C, for example, 30°C, 32°C, 34°C, 36°C, 38°C, 40°C, 42°C, 44°C, 46°C, 48°C, 50°C, 52°C, 54°C, 56°C, 58°C, 60°C.

[0058] Furthermore, in step (2), the base is one of sodium hydroxide, potassium hydroxide, sodium carbonate, sodium bicarbonate, potassium carbonate or potassium bicarbonate.

[0059] In a specific embodiment, in step (2), the molar ratio of the branched ester compound, the hydroxylamine salt and the base is 1:2.2-2.3:4.4-4.5.

[0060] In a specific embodiment, R is an alkyl group with 8-10 carbon atoms, preferably, R is an octyl group or a decyl group. When R is an alkyl group with 8-10 carbon atoms, the collector has better capture and selectivity, and low or high carbon atoms will affect the capture and selectivity.

[0061] The flotation method of the present invention can be used not only for ilmenite, but also for the flotation of phosphate ore, rutile, fluorite, tungsten ore and the like.

[0062] The technical solution of the present invention is further explained below in conjunction with specific embodiments. All raw materials in the present invention are commercially available raw materials.

[0063] Example 1

[0064] The present embodiment provides an efficient flotation method for ilmenite, comprising the following steps: subjecting the raw ore pulp to a first microwave pretreatment, wherein the microwave power is 500 W and the treatment time is 4 min, and then subjecting the raw ore pulp to a second microwave pretreatment, wherein the microwave power is 900 W and the treatment time is 6 min after fucoidan is added, and then subjecting the raw ore pulp to a first flotation, wherein the microwave power is 900 W and the treatment time is 6 min, and then subjecting the raw ore pulp to a second flotation, wherein sulfuric acid is added during the first flotation and the second flotation, wherein sulfuric acid is added during the first flotation to make the pulp pH = 4.5, and wherein sulfuric acid is added during the second flotation to make the pulp pH = 3.5, and then subjecting the raw ore pulp to a ilmenite concentrate;

[0065] The mass concentration of the raw ore pulp is 30%, the amount of fucoidan added is 100 g / t, and the amount of collector added is 500 g / t.

[0066] The chemical structural formula of the collector is as follows:

[0067]

[0068] The preparation method of the collector of the present embodiment is as follows:

[0069] (1) Diethyl malonate, octanal and 1-butyl-3-methylimidazole were weighed in a molar ratio of 1:1:0.4, and diethyl malonate and 1-butyl-3-methylimidazole were dispersed in ethanol to mix them evenly. The mixture was first reacted at 25-35°C in a 100 mL round-bottom flask for 3-5 min, and then octanal was slowly added dropwise and the reaction was continued for 30-60 min. After the reaction was completed, ether was used for extraction 3-4 times to obtain the product diethyl 2-octylene-1,3-malonate.

[0070] (2) Weigh diethyl 2-octyl-1,3-malonate, hydroxylamine hydrochloride and NaOH in a molar ratio of 1:2.2:4.4, dissolve hydroxylamine hydrochloride and NaOH in 40 mL of methanol, respectively, disperse and dissolve by ultrasonication, mix them, and stir in an ice-water bath for 0.5 to 1.5 h to fully free hydroxylamine, then add diethyl 2-octyl-1,3-malonate, heat to 30° C. and react for 6 h to obtain sodium 2-octyl-1,3-malonate.

[0071] (3) The solution was acidified with 1.06 mol / L hydrochloric acid to adjust the pH to 5-6, and filtered to obtain a white solid as a crude product of 2-octylene-1,3-propanedihydroxamic acid. The crude product of 2-octylene-1,3-propanedihydroxamic acid was dispersed in ethyl acetate, filtered with a sand core funnel to remove the ethyl acetate, dried, and ground to obtain a relatively pure product of 2-octylene-1,3-propanedihydroxamic acid (i.e., collector).

[0072] The infrared spectrum of the collector prepared in this example is as follows Figure 1 As shown, the mass spectrum (M+Na) of the collector prepared in this embodiment is as follows Figure 2 As shown, the nuclear magnetic resonance image of the collector prepared in this embodiment is as follows Figure 3 shown.

[0073] Example 2

[0074] The present embodiment provides an efficient ilmenite flotation method, comprising the following steps: subjecting the raw ore pulp to a first microwave pretreatment, wherein the microwave power is 400 W and the treatment time is 5 min, and then subjecting the raw ore pulp to a second microwave pretreatment, wherein the microwave power is 700 W and the treatment time is 8 min after fucoidan is added, and then subjecting the raw ore pulp to a first microwave pretreatment, wherein the microwave power is 700 W and the treatment time is 8 min, and then subjecting the raw ore pulp to a first flotation to obtain a coarse concentrate, and subjecting the coarse concentrate to a second flotation, and further adding sulfuric acid during the first flotation and the second flotation, wherein sulfuric acid is added during the first flotation to make the pulp pH = 4, and sulfuric acid is added during the second flotation to make the pulp pH = 3, and then subjecting the raw ore pulp to a ilmenite concentrate;

[0075] The mass concentration of the raw ore pulp is 35%, the amount of fucoidan added is 200 g / t, and the amount of collector added is 650 g / t.

[0076] The chemical structural formula of the collector is as follows:

[0077]

[0078] The preparation method of the collector of the present embodiment is as follows:

[0079] (1) Diethyl malonate, octanal and 1-butyl-3-methylimidazole were weighed in a molar ratio of 1:1.05:0.4, diethyl malonate and 1-butyl-3-methylimidazole were dispersed in ethanol and mixed evenly, first reacted at 25-35°C in a 100 mL round-bottom flask for 3-5 min, then octanal was slowly added dropwise and the reaction was continued for 30-60 min. After the reaction was completed, ether was used for extraction 3-4 times to obtain the product 2-octylene-1,3-diethyl malonate.

[0080] (2) Weigh diethyl 2-octyl-1,3-malonate, hydroxylamine hydrochloride and NaOH in a molar ratio of 1:2.25:4.45, dissolve hydroxylamine hydrochloride and NaOH in 40 mL of methanol, dissolve by ultrasonic dispersion, mix them, and stir in an ice-water bath for 0.5 to 1.5 h to fully free hydroxylamine, then add diethyl 2-octyl-1,3-malonate, heat to 45° C. and react for 5 h to obtain sodium 2-octyl-1,3-malonate.

[0081] (3) The solution was acidified with 1.06 mol / L hydrochloric acid to adjust the pH to 5-6, and filtered to obtain a white solid as a crude product of 2-octylene-1,3-propanedihydroxamic acid. The crude product of 2-octylene-1,3-propanedihydroxamic acid was dispersed in ethyl acetate, filtered with a sand core funnel to remove the ethyl acetate, dried, and ground to obtain a relatively pure product of 2-octylene-1,3-propanedihydroxamic acid (i.e., collector).

[0082] The collector prepared in this example was also tested in Example 1, and the results were basically the same. Due to limited space, they are not listed one by one.

[0083] Example 3

[0084] The present embodiment provides an efficient flotation method for ilmenite, comprising the following steps: subjecting the original ore pulp to a first microwave pretreatment, wherein the microwave power is 800 W and the treatment time is 1 min, and then subjecting the raw ore pulp to a second microwave pretreatment, wherein the microwave power is 1000 W and the treatment time is 3 min after fucoidan is added, and then subjecting the raw ore pulp to a first microwave pretreatment, wherein the microwave power is 1000 W and the treatment time is 3 min, and then subjecting the raw ore pulp to a first flotation to obtain a coarse concentrate, and subjecting the coarse concentrate to a second flotation, and further adding sulfuric acid during the first flotation and the second flotation, wherein sulfuric acid is added during the first flotation to make the pulp pH = 5, and sulfuric acid is added during the second flotation to make the pulp pH = 4, and then subjecting the raw ore pulp to a ilmenite concentrate;

[0085] The mass concentration of the raw ore pulp is 40%, the amount of fucoidan added is 300 g / t, and the amount of collector added is 800 g / t.

[0086] The chemical structural formula of the collector is as follows:

[0087]

[0088] The preparation method of the collector of the present embodiment is as follows:

[0089] (1) Diethyl malonate, octanal and 1-butyl-3-methylimidazole were weighed in a molar ratio of 1:1.1:0.4, diethyl malonate and 1-butyl-3-methylimidazole were dispersed in ethanol and mixed evenly, first reacted at 25-35°C in a 100 mL round-bottom flask for 3-5 min, then octanal was slowly added dropwise and the reaction was continued for 30-60 min. After the reaction was completed, ether was used for extraction 3-4 times to obtain the product 2-octylene-1,3-diethyl malonate.

[0090] (2) Weigh 2-octyl-1,3-malonic acid diethyl ester (5 g), hydroxylamine hydrochloride (2.96-6.80 g) and NaOH (3.25-3.33 g) in a molar ratio of 1:2.3:4.5, dissolve hydroxylamine hydrochloride and NaOH in 40 mL of methanol, dissolve by ultrasonic dispersion, mix them, and stir in an ice-water bath for 0.5-1.5 h to fully free hydroxylamine, then add 2-octyl-1,3-malonic acid diethyl ester, heat to 60° C. and react for 4 h to obtain 2-octyl-1,3-malonic acid sodium dihydroxamate.

[0091] (3) The solution was acidified with 1.06 mol / L hydrochloric acid to adjust the pH to 5-6, and filtered to obtain a white solid as a crude product of 2-octylene-1,3-propanedihydroxamic acid. The crude product of 2-octylene-1,3-propanedihydroxamic acid was dispersed in ethyl acetate, filtered with a sand core funnel to remove the ethyl acetate, dried, and ground to obtain a relatively pure product of 2-octylene-1,3-propanedihydroxamic acid (i.e., collector).

[0092] The collector prepared in this example was also tested in Example 1, and the results were basically the same. Due to limited space, they are not listed one by one.

[0093] Example 4

[0094] The efficient separation method of ilmenite in this embodiment is the same as that in Example 1, except that the structural formula of the collector is as follows:

[0095]

[0096] The collector of this embodiment is prepared by the following method:

[0097] (1) Diethyl malonate, decanal and 1-butyl-3-methylimidazole were weighed in a molar ratio of 1:1:0.4, and diethyl malonate and 1-butyl-3-methylimidazole were dispersed in ethanol to mix them evenly. The mixture was first reacted in a 100 mL round-bottom flask at 25-35°C for 3-5 min, and then octanal was slowly added dropwise and the reaction was continued for 30-60 min. After the reaction was completed, ether was used for extraction 3-4 times to obtain the product diethyl 2-decylidene-1,3-malonate.

[0098] (2) Weigh diethyl 2-decylidene-1,3-malonate, hydroxylamine hydrochloride and NaOH in a molar ratio of 1:2.2:4.4, dissolve hydroxylamine hydrochloride and NaOH in 40 mL of methanol, respectively, disperse and dissolve by ultrasonication, mix them, and stir in an ice-water bath for 0.5 to 1.5 h to fully free hydroxylamine, then add diethyl 2-decylidene-1,3-malonate, heat to 30° C. and react for 6 h to obtain sodium diethyl 2-decylidene-1,3-malonate.

[0099] (3) The solution was acidified with 1.0 mol / L hydrochloric acid to adjust the pH to 5-6, and filtered to obtain a white solid as a crude product of 2-decylidene-1,3-propanedioic acid diethyl ester. The crude product of 2-decylidene-1,3-propanedioic acid diethyl ester was dispersed in ethyl acetate, filtered with a sand core funnel to remove the ethyl acetate, dried, and ground to obtain a relatively pure product of 2-decylidene-1,3-propanedioic acid dihydroxamic acid (i.e., collector).

[0100] Example 5

[0101] The efficient separation method of ilmenite in this embodiment is the same as that in Example 2, except that the structural formula of the collector is as follows:

[0102]

[0103] The collector of this embodiment is prepared by the following method:

[0104] (1) Diethyl malonate, decanal and 1-butyl-3-methylimidazole were weighed in a molar ratio of 1:1.05:0.4, and diethyl malonate and 1-butyl-3-methylimidazole were dispersed in ethanol to mix them evenly. The mixture was first reacted at 25-35°C for 3-5 minutes in a 100 mL round-bottom flask, and then decanal was slowly added dropwise and the reaction was continued for 30-60 minutes. After the reaction was completed, ether was used for extraction 3-4 times to obtain the product 2-decylidene-1,3-diethyl malonate.

[0105] (2) Weigh diethyl 2-decylidene-1,3-malonate, hydroxylamine hydrochloride and NaOH in a molar ratio of 1:2.25:4.45, dissolve hydroxylamine hydrochloride and NaOH in 40 mL of methanol, dissolve by ultrasonic dispersion, mix them, and stir in an ice-water bath for 0.5 to 1.5 h to fully free hydroxylamine, then add diethyl 2-decylidene-1,3-malonate, heat to 45° C. and react for 5 h to obtain sodium diethyl 2-decylidene-1,3-malonate.

[0106] (3) The solution was acidified with 1.0 mol / L hydrochloric acid to adjust the pH to 5-6, and filtered to obtain a white solid as a crude product of 2-decylidene-1,3-propanedioic acid diethyl ester. The crude product of 2-decylidene-1,3-propanedioic acid diethyl ester was dispersed in ethyl acetate, filtered with a sand core funnel to remove the ethyl acetate, dried, and ground to obtain a relatively pure product of 2-decylidene-1,3-propanedioic acid dihydroxamic acid (i.e., collector).

[0107] Example 6

[0108] The efficient separation method of ilmenite in this embodiment is the same as that in Example 3, except that the structural formula of the collector is as follows:

[0109]

[0110] The collector of this embodiment is prepared by the following method:

[0111] (1) Diethyl malonate, decanal and 1-butyl-3-methylimidazole were weighed in a molar ratio of 1:1.1:0.4, and diethyl malonate and 1-butyl-3-methylimidazole were dispersed in ethanol to mix them evenly. The mixture was first reacted in a 100 mL round-bottom flask at 25-35°C for 3-5 min, and then octanal was slowly added dropwise and the reaction was continued for 30-60 min. After the reaction was completed, ether was used for extraction 3-4 times to obtain the product diethyl 2-decylidene-1,3-malonate.

[0112] (2) Weigh diethyl 2-decylidene-1,3-malonate, hydroxylamine hydrochloride and NaOH in a molar ratio of 1:2.3:4.5, dissolve hydroxylamine hydrochloride and NaOH in 40 mL of methanol, respectively, disperse and dissolve by ultrasonication, mix them, and stir in an ice-water bath for 0.5 to 1.5 h to fully free hydroxylamine, then add diethyl 2-decylidene-1,3-malonate, heat to 60° C. and react for 4 h to obtain sodium diethyl 2-decylidene-1,3-malonate.

[0113] (3) The solution was acidified with 1.0 mol / L hydrochloric acid to adjust the pH to 5-6, and filtered to obtain a white solid as a crude product of 2-decylidene-1,3-propanedioic acid diethyl ester. The crude product of 2-decylidene-1,3-propanedioic acid diethyl ester was dispersed in ethyl acetate, filtered with a sand core funnel to remove the ethyl acetate, dried, and ground to obtain a relatively pure product of 2-decylidene-1,3-propanedioic acid dihydroxamic acid (i.e., collector).

[0114] Comparative Example 1

[0115] The high-efficiency flotation method of ilmenite in this comparative example is the same as that in Example 1, except that fucoidan is not added.

[0116] Comparative Example 2

[0117] The high-efficiency ilmenite flotation method of this comparative example is the same as that of Example 1, except that the first microwave pretreatment is removed.

[0118] Comparative Example 3

[0119] The high-efficiency ilmenite flotation method of this comparative example is the same as that of Example 1, except that the second microwave pretreatment is removed.

[0120] Comparative Example 4

[0121] The high-efficiency ilmenite flotation method of this comparative example is the same as that of Example 1, except that the microwave power of the second microwave treatment is 600 W and the treatment time is 10 min.

[0122] Comparative Example 5

[0123] The high-efficiency flotation method of ilmenite in this comparative example is the same as that in Example 1, except that the structural formula of the collector is as follows:

[0124]

[0125] Comparative Example 6

[0126] The high-efficiency flotation method of ilmenite in this comparative example is the same as that in Example 1, except that the collector is octylhydroxamic acid.

[0127] Test Example 1

[0128] The flotation processes of Examples 1-6 and Comparative Examples 1-6 were respectively used to flotate actual ilmenite ore with a grade of 14.97%, with a pulp volume of 1.5 L. The flotation results are shown in Table 1.

[0129] Table 1

[0130]

[0131] The results of Example 1 and Comparative Example 1 show that the use of inhibitors can effectively improve the grade and recovery rate of concentrate and improve the separation efficiency of target minerals and gangue minerals.

[0132] The results of Example 1 and Comparative Example 2 show that the first microwave pretreatment of ilmenite and the addition of inhibitors can effectively improve the separation efficiency of ilmenite and gangue minerals, improve the yield and grade of ilmenite flotation concentrate, and achieve efficient separation of target minerals and gangue minerals.

[0133] The results of Example 1 and Comparative Example 3 show that the second microwave treatment can not only decompose the macromolecular inhibitor into inhibitors with lower molecular weight, enhancing the competitive adsorption process of the collector on the surface of the target mineral, but also microwave treatment makes the chemical adsorption of the inhibitor and the gangue mineral stronger.

[0134] The results of Example 1 and Comparative Examples 5-6 show that the collector used in the present invention has a good collecting effect and selectivity for ilmenite compared with the collector in the prior art, and can achieve efficient separation of ilmenite.

[0135] Test Example 2

[0136] The flotation methods of Examples 1-6 and Comparative Examples 1-6 were respectively used to flotate actual ilmenite ore with a grade of 14.97%. The slurry was 1.5 L. The flotation under different collector dosages was investigated to obtain the TiO2 grade and recovery rate in the concentrate. The results are shown in Table 2.

[0137] Table 2

[0138]

[0139]

[0140] The TiO2 grade and recovery rate in the concentrate obtained by flotation under different collector dosages were investigated. The results showed that the optimal dosage of the collector in the present invention was 650 g / t. With the increase of the collector dosage, the yield of the ilmenite concentrate increased, but the grade and recovery rate decreased, which shows that the dosage of the reagent in the present invention is relatively low. In addition, the collectors used in comparative examples 5 and 6 for flotation of ilmenite have never achieved the flotation effect of the collector in the present invention.

[0141] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A highly selective flotation method for minerals, characterized in that: The method comprises the following steps: subjecting the raw ore pulp to a first microwave pretreatment, adding fucoidan and subjecting it to a second microwave pretreatment, adding a collector and subjecting it to a first flotation to obtain a coarse concentrate, subjecting the coarse concentrate to a second flotation to obtain an ilmenite concentrate; The chemical structural formula of the collector is shown in formula (I): Wherein, R is an alkyl group.

2. A highly selective flotation method for a mineral according to claim 1, characterized in that: The microwave power of the first microwave pretreatment is 400-800W, and the processing time is 1-5min. The microwave power of the second microwave pretreatment is 700-1000W, and the processing time is 3-8min.

3. The high-selectivity flotation method for a mineral according to claim 1, characterized in that: Sulfuric acid is also added during the first and second flotation. Preferably, sulfuric acid is added during the first flotation to make the pulp pH = 4-5, and sulfuric acid is added during the second flotation to make the pulp pH = 3-4.

4. A highly selective flotation method for a mineral according to any one of claims 1 to 3, characterized in that: The added amount of fucoidan is 100-300g / t.

5. A highly selective flotation method for a mineral according to any one of claims 1 to 3, characterized in that: The collector is prepared by the following method: (1) dissolving an ester compound and a catalyst in a dispersant, and then adding an aldehyde to carry out a substitution reaction to obtain an ester compound with a branched chain; (2) dissolving the hydroxylamine salt and the alkali in methanol, dispersing and dissolving them by ultrasonication, mixing them and reacting them in an ice-water bath, adding the branched ester compound, heating them for hydroxyoximation reaction, adjusting the pH, filtering them, and drying them to obtain the collector.

6. A highly selective flotation method for a mineral according to claim 5, characterized in that: In step (1), the ester compound is dimethyl malonate or diethyl malonate; The catalyst is one of 1-butyl-3-methylimidazole, N-butylpyridine nitrate, 1-hexyl-3-methylimidazole hexafluorophosphate, and 1-hexyl-3-methylimidazole hexafluorophosphate; The dispersant is methanol or ethanol; The aldehyde is one of octanal and decanal.

7. A highly selective flotation method for minerals according to claim 5, characterized in that: In step (1), the molar ratio of the ester compound, the aldehyde and the catalyst is 1:1 to 1.1:0.

4.

8. The high-selectivity flotation method for a mineral according to claim 5, characterized in that: In step (2), the hydroxylamine salt is one of hydroxylamine hydrochloride, hydroxylamine carbonate or hydroxylamine sulfate.

9. The high-selectivity flotation method for a mineral according to claim 5, characterized in that: In step (2), the heating temperature is 30 to 60°C.

10. The high-selectivity flotation method for a mineral according to claim 5, characterized in that: In step (2), the molar ratio of the branched ester compound, the hydroxylamine salt and the base is 1:2.2-2.3:4.4-4.5.

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