A high selectivity flotation process for a mineral

Abstract

The present application relates to a kind of high selectivity mineral flotation method, belong to flotation technology, to solve at least one of the problems such as poor mineral collecting effect, poor selectivity, large amount of collector in the existing flotation method.The first microwave pretreatment is used in the present application to strip the impurities on the surface of ilmenite ore, and part of Fe 2+ On the surface of iron-titanium ore is converted into Fe 3+ , which is more conducive to the selective adsorption of flotation reagent on the surface of mineral. After adding fucoidan to the ore pulp, the second microwave pretreatment is carried out, which can make the fucoidan in the ore pulp break down to form small molecular weight inhibitors, and the microwave catalysis can enhance the reactivity of fucoidan. Therefore, the process of selective adsorption of fucoidan on the gangue surface is more stable, which not only can improve the effect of inhibition, but also can effectively reduce the amount of collector.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of flotation, in particular to a high selectivity flotation method of minerals. BACKGROUND

[0002] Titanium resources are abundant in China, accounting for about 28% of the total reserves in the world. Ilmenite is the main source of titanium resources in China, mainly distributed in Panzhihua and Xichang areas of Sichuan. The ilmenite resources in China are characterized by "more lean ore, less rich ore, and fine particle size", which makes it difficult to achieve efficient separation and restricts the further utilization of titanium resources. Flotation is an important method to realize efficient separation of fine-grained mineral resources. Due to the similar surface properties of the target mineral and the gangue mineral, traditional fatty acid collectors have good collecting properties, but it is difficult to achieve high-efficiency separation of the two. Arsonic acid and phosphoric acid collectors have certain collecting properties and selectivity, but there are problems such as environmental pollution, so it is necessary to develop environmentally friendly high-selectivity flotation collectors.

[0003] In recent years, hydroxamic acid collectors have received widespread attention in ilmenite flotation process due to their excellent flotation performance, but the collecting property 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

[0004] In view of the above analysis, the present application aims to provide a high selectivity flotation method of minerals, which at least solves one of the problems of poor collecting effect, poor selectivity, and large amount of collector in the existing one-rough and one-fine flotation method.

[0005] In a first aspect, the present application provides a high selectivity flotation method of minerals, comprising the following steps: after the first microwave pretreatment of the raw ore slurry, adding fucoidan for the second microwave pretreatment, adding a collector for the first flotation to obtain a rough concentrate, and then carrying out the second flotation on the rough concentrate to obtain an ilmenite concentrate.

[0006] The chemical structure of the collector is shown as formula (I):

[0007]

[0008] Wherein, R is an alkyl group.

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

[0010] Further, sulfuric acid is added in the first and second flotation, preferably, the pH of the slurry is 4-5 in the first flotation, and the pH of the slurry is 3-4 in the second flotation.

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

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

[0013] (1) dissolving the ester compound and the catalyst in the dispersant, then adding aldehyde to perform substitution reaction to obtain branched ester compound;

[0014] (2) dissolving the hydroxylamine salt and the base in methanol, ultrasonic dispersion and dissolution, mixing to perform ice water bath free reaction, then adding the branched ester compound, heating to perform hydroxamidation reaction, adjusting pH, filtering and drying to obtain the collector.

[0015] Further, 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 hexaphosphoric acid and 1-hexyl-3-methylimidazole hexaphosphoric acid;

[0017] The dispersant is methanol or ethanol;

[0018] The aldehyde is one of octyl aldehyde and decyl aldehyde.

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

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

[0021] Further, in step (2), the heating temperature is 30-60℃.

[0022] Further, 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 application can achieve at least one of the following beneficial effects:

[0024] (1) In the present application, the first microwave pretreatment is used to strip the impurities on the surface of ilmenite ore, and at the same time, part of Fe 2+ on the surface of ilmenite is converted into Fe 3+More beneficial to the selective adsorption of the flotation reagent on the mineral surface. After adding fucoidan to the ore pulp and performing the second microwave pretreatment, the fucoidan in the ore pulp can be broken to form small molecular weight inhibitors, and the microwave catalysis can enhance the reaction activity of the fucoidan, so that the process of the selective adsorption of the fucoidan on the gangue surface is more stable, which not only can improve the effect of the inhibition, but also can effectively reduce the dosage of the collector;

[0025] (2) The present application combines the olefin-based bifunctional collector with high selectivity, the polar group of the collector is hydroxylamine, and the non-polar group contains a double bond. One of the hydroxylamines can be combined with the active sites on the ilmenite surface to form a stable chelate ring, the other hydroxylamine can rotate flexibly, and the induction effect between the two polar groups is reduced. 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 molecules, improving the concentrate grade and recovery rate, and reducing the dosage of the collector.

[0026] In the present application, the above technical solutions can be combined with each other to realize more preferred combination solutions. Other features and advantages of the present application will be described in the subsequent specification, and some advantages will become apparent from the specification, or will be understood by implementing the present application. The purposes and other advantages of the present application can be realized and obtained through the contents specifically indicated in the specification and the drawings. BRIEF DESCRIPTION OF DRAWINGS

[0027] The accompanying drawings are included to provide a further understanding of the application and are incorporated in and constitute a part of this specification, illustrate embodiments of the application and serve to explain the principles of the application.

[0028] Figure 1 The infrared spectrum of the collector prepared for the embodiment 1 of the present application;

[0029] Figure 2 The mass spectrum of the collector prepared for the embodiment 1 of the present application;

[0030] Figure 3 The nuclear magnetic resonance spectrum of the collector prepared for the embodiment 1 of the present application. DETAILED DESCRIPTION

[0031] The preferred embodiments of the present application will be specifically described below in combination with the drawings, wherein the drawings constitute a part of the present application and are used to illustrate the principles of the embodiments of the present application, and are not used to limit the scope of the present application.

[0032] One specific embodiment of the present application discloses a high-selectivity mineral flotation method, comprising the following steps: after first microwave pretreatment of raw ore slurry, adding fucoidan for second microwave pretreatment, adding collector for first flotation to obtain rough concentrate, and second flotation of the rough concentrate to obtain ilmenite concentrate.

[0033] The chemical structure of the collector is shown as formula (I):

[0034]

[0035]

[0036] Wherein, R is alkyl.

[0037] Compared with the prior art, in the present application, first microwave pretreatment is adopted to strip the impurities on the surface of ilmenite raw ore, and at the same time, part of Fe 2+ on the surface of ilmenite is converted into Fe 3+ , which is more conducive to selective adsorption of flotation reagents on the surface of minerals. After adding fucoidan to the slurry for second microwave pretreatment, the fucoidan in the slurry is broken to form small molecular weight inhibitors, and the microwave catalysis enhances the reaction activity of fucoidan, so that the selective adsorption of fucoidan on the surface of gangue is more stable, which not only improves the effect of inhibition, but also effectively reduces the dosage of the collector.

[0038] In addition, the present application combines a selective olefin-based bifunctional collector, the polar group of the collector is hydroxylamine, and the non-polar group contains a double bond. One of the hydroxylamines can be combined with the active sites on the surface of ilmenite to form a stable chelate ring, and the other hydroxylamine can rotate flexibly and reduce the induction 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 molecules, improving the concentrate grade and recovery rate, and reducing the dosage of the collector.

[0039] In one 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 raw ore added into water to form.

[0041] Specifically, the raw ore in the present application is calcium and magnesium rich ilmenite, the gangue mineral is forsterite and titanic augite, 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 processing time is 1-5 min, for example, 1 min, 1.5 min, 2 min, 2.5 min, 3 min, 3.5 min, 4 min, 4.5 min, 5 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, 880 W, 900 W, 920 W, 940 W, 960 W, 980 W, 1000 W, and the processing 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 further added in the first and second flotation.

[0044] Preferably, the pH of the slurry is 4-5 in the first flotation, and the pH of the slurry is 3-4 in the second flotation.

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

[0046] Specifically, the time of the two flotations is the same.

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

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

[0049] (1) dissolving the ester compound and the catalyst in a dispersing agent, and then adding an aldehyde to perform a substitution reaction to obtain an ester compound with a branched chain;

[0050] (2) dissolving a hydroxylamine salt and a base in methanol, ultrasonic dispersion and dissolution, and then mixing to perform a free reaction in an ice water bath, and then adding the ester compound with a branched chain to perform a hydroxamic acid reaction, adjusting the pH, filtering, and drying to obtain the collector.

[0051] In one 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 hexaphosphoric acid, and 1-hexyl-3-methylimidazole hexaphosphoric acid.

[0053] The dispersing agent is methanol or ethanol.

[0054] The aldehyde is one of octyl aldehyde and decyl aldehyde.

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

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

[0057] In one 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, or 60°C.

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

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

[0060] In one specific embodiment, R is an alkyl group with 8-10 carbon atoms, and preferably, R is an octyl group or a decyl group. When R is an alkyl group with 8-10 carbon atoms, the collecting property and selectivity of the collector are better, and a lower or higher number of carbon atoms will affect the collecting property and selectivity.

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

[0062] The technical solutions of the application are further explained in combination with specific examples, and each raw material in the application is a commercially available raw material.

[0063] Example 1

[0064] The ilmenite high-efficiency flotation method of the example comprises the following steps: after first microwave pretreatment of an ore pulp, microwave power is 500 W, and the treatment time is 4 min; after second microwave pretreatment after adding fucoidan, microwave power is 900 W, and the treatment time is 6 min; first flotation is performed after adding a collector, and a rough concentrate is obtained; the rough concentrate is subjected to second flotation, and sulfuric acid is further added during the first and second flotation; the sulfuric acid added during the first flotation makes the pH of the ore pulp 4.5, and the sulfuric acid added during the second flotation makes the pH of the ore pulp 3.5, and an ilmenite concentrate is obtained.

[0065] The mass concentration of the ore pulp is 30%. The addition amount of fucoidan is 100 g / t, and the addition amount of the collector 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 example is as follows:

[0069] (1) Take malonic acid diethyl ester, octanal and 1-butyl-3-methyl imidazole in a molar ratio of 1:1:0.4, disperse malonic acid diethyl ester and 1-butyl-3-methyl imidazole in ethanol to mix them uniformly, first react at 25-35℃ in a 100 mL round-bottom flask for 3-5 min, then slowly drop octanal, and continue to react for 30-60 min, after the reaction is completed, extract 3-4 times with diethyl ether, and obtain the product 2-octylene-1,3-malonic acid diethyl ester.

[0070] (2) Take 2-octylene-1,3-malonic acid diethyl ester, hydroxylamine hydrochloride and NaOH in a molar ratio of 1:2.2:4.4, and dissolve hydroxylamine hydrochloride and NaOH in 40 mL of methanol respectively, ultrasonic dispersion and dissolution, then mix them, stir in an ice water bath for 0.5-1.5 h to make the hydroxylamine fully dissociate, then add 2-octylene-1,3-malonic acid diethyl ester, and react at 30℃ for 6 h to prepare 2-octylene-1,3-malonic acid sodium hydroxamate.

[0071] (3) using 1.06 mol / L hydrochloric acid to adjust the pH of the solution to 5-6, filtering, obtaining white solid as 2-octylene-1,3-propanediol hydroxamic acid crude product. Dispersing 2-octylene-1,3-propanediol hydroxamic acid crude product in ethyl acetate, filtering to remove ethyl acetate using a sand core funnel, drying, grinding to obtain 2-octylene-1,3-propanediol hydroxamic acid relatively pure product (i.e. collector).

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

[0073] Example 2

[0074] The ilmenite efficient flotation method of this example includes the following steps: after the first microwave pretreatment of the raw ore slurry, the microwave power is 400 W, the treatment time is 5 min, after the addition of fucoidan, the second microwave pretreatment is carried out, the microwave power is 700 W, the treatment time is 8 min, the collector is added for the first flotation, and the rough concentrate is obtained. The rough concentrate is subjected to the second flotation, and sulfuric acid is also added during the first and second flotations. The pH of the slurry is 4 after the addition of sulfuric acid in the first flotation, and the pH of the slurry is 3 after the addition of sulfuric acid in the second flotation, and the ilmenite concentrate is obtained.

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

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

[0077]

[0078] The preparation method of the collector of this example is as follows:

[0079] (1) taking malonic acid diethyl ester, octanal and 1-butyl-3-methyl imidazole in a molar ratio of 1:1.05:0.4, dispersing malonic acid diethyl ester and 1-butyl-3-methyl imidazole in ethanol to mix them uniformly, first reacting in a 100 mL round-bottom flask at 25-35°C for 3-5 min, then slowly adding octanal, and continuing to react for 30-60 min. After the reaction is completed, the product 2-octylene-1,3-malonic acid diethyl ester is obtained by extracting 3-4 times with diethyl ether.

[0080] ​(2) Weigh 2-octyl-1,3-malonic acid diethyl ester, hydroxylamine hydrochloride and NaOH in a molar ratio of 1:2.25:4.45. 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 0.5-1.5 h to allow hydroxylamine to be fully released. Then add 2-octyl-1,3-malonic acid diethyl ester and heat to 45 °C for 5 h to prepare sodium 2-octyl-1,3-malonic acid dihydroxyoxime.

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

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

[0083] Example 3

[0084] This embodiment of a high-efficiency flotation method for ilmenite includes the following steps: The raw ore pulp undergoes a first microwave pretreatment with a microwave power of 800W for 1 minute; fucoidan is added, followed by a second microwave pretreatment with a microwave power of 1000W for 3 minutes; a collector is added for the first flotation to obtain a rough concentrate; the rough concentrate is then subjected to a second flotation. Sulfuric acid is added during both the first and second flotation processes. In the first flotation, sulfuric acid is added to adjust the pulp pH to 5; in the second flotation, sulfuric acid is added to adjust the pulp pH to 4, resulting in an ilmenite concentrate.

[0085] The raw ore slurry has a mass concentration of 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 shown below:

[0087]

[0088] The method for preparing the collector in this 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 to mix uniformly, first reacted at 25-35℃ for 3-5 min in a 100 mL round-bottom flask, then octanal was slowly added dropwise, and the reaction was continued for 30-60 min, after the reaction was completed, diethyl ether was used for extraction for 3-4 times to obtain the product diethyl 2-octylidene-1,3-propanedioate.

[0090] (2) Diethyl 2-octylidene-1,3-propanedioate (5 g), hydroxylamine hydrochloride (2.96-6.80 g) and NaOH (3.25-3.33 g) were weighed in a molar ratio of 1:2.3:4.5, and hydroxylamine hydrochloride and NaOH were respectively dissolved in 40 mL of methanol and ultrasonically dispersed and dissolved, then after mixing, the mixture was stirred in an ice water bath for 0.5-1.5 h to make the hydroxylamine fully dissociate, then diethyl 2-octylidene-1,3-propanedioate was added, and the temperature was raised to 60℃ for reaction for 4 h to prepare sodium 2-octylidene-1,3-propanedioate hydroxamate.

[0091] (3) The solution pH was adjusted to 5-6 by using 1.06 mol / L hydrochloric acid, and filtration was performed to obtain white solid as crude 2-octylidene-1,3-propanedioate hydroxamate. The crude 2-octylidene-1,3-propanedioate hydroxamate was dispersed in ethyl acetate, the ethyl acetate was removed by filtration using a sand core funnel, dried, and ground to obtain a relatively pure product of 2-octylidene-1,3-propanedioate hydroxamate (i.e. collector).

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

[0093] Example 4

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

[0095]

[0096] The collector in this example was 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, diethyl malonate and 1-butyl-3-methylimidazole were dispersed in ethanol to mix uniformly, first reacted at 25-35℃ for 3-5 min in a 100 mL round-bottom flask, then decanal was slowly added dropwise, and the reaction was continued for 30-60 min, after the reaction was completed, diethyl ether was used for extraction for 3-4 times to obtain the product diethyl 2-decylidene-1,3-propanedioate.

[0098] (2) Take 2-decylidene-1,3-propanedioic acid diethyl ester, hydroxylamine hydrochloride and NaOH in a molar ratio of 1:2.2:4.4, and dissolve the hydroxylamine hydrochloride and NaOH in 40 mL of methanol respectively, and then mix them together and stir in an ice water bath for 0.5-1.5 h to make the hydroxylamine fully dissociate, and then add 2-decylidene-1,3-propanedioic acid diethyl ester and heat to 30°C for 6 h to obtain 2-decylidene-1,3-propanedioic acid diethyl ester sodium.

[0099] (3) Adjust the pH of the solution to 5-6 by using 1.0 mol / L hydrochloric acid, and filter to obtain white solid 2-decylidene-1,3-propanedioic acid diethyl ester crude product. Disperse the 2-decylidene-1,3-propanedioic acid diethyl ester crude product in ethyl acetate, filter out the ethyl acetate using a sand core funnel, dry and grind to obtain 2-decylidene-1,3-propanedioic acid dihydroxamic acid pure product (i.e. the collector)

[0100] Example 5

[0101] The method for efficiently separating ilmenite in this example is the same as that in Example 2, except that the structural formula of the collector is as follows:

[0102]

[0103] The collector in this example is prepared by the following method:

[0104] (1) Take malonic acid diethyl ester, decanal (and 1-butyl-3-methylimidazole) in a molar ratio of 1:1.05:0.4, disperse the malonic acid diethyl ester and 1-butyl-3-methylimidazole in ethanol to mix them evenly, first react in a 100 mL round-bottom flask at 25-35°C for 3-5 min, then slowly add octanal, and continue to react for 30-60 min. After the reaction is completed, extract the product 2-decylidene-1,3-propanedioic acid diethyl ester with diethyl ether for 3-4 times.

[0105] (2) Take 2-decylidene-1,3-propanedioic acid diethyl ester, hydroxylamine hydrochloride and NaOH in a molar ratio of 1:2.25:4.45, and dissolve the hydroxylamine hydrochloride and NaOH in 40 mL of methanol respectively, and then mix them together and stir in an ice water bath for 0.5-1.5 h to make the hydroxylamine fully dissociate, and then add 2-decylidene-1,3-propanedioic acid diethyl ester and heat to 45°C for 5 h to obtain 2-decylidene-1,3-propanedioic acid diethyl ester sodium.

[0106] (3) 1.0 mol / L hydrochloric acid was used to adjust the pH of the solution to 5-6, and filtration was performed to obtain the crude product of 2-decylidene-1,3-propanedioic acid diethyl ester in the form of white solid. The crude product of 2-decylidene-1,3-propanedioic acid diethyl ester was dispersed in ethyl acetate, and the ethyl acetate was removed by filtration using a sand core funnel. After drying and grinding, the relatively pure product of 2-decylidene-1,3-propanedioic acid dihydroxamic acid (i.e., the collector) was obtained.

[0107] Example 6

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

[0109]

[0110] The collector in this example was prepared by the following method:

[0111] (1) The molar ratio of malonic acid diethyl ester, decanal, and 1-butyl-3-methylimidazole was 1:1.1:0.4. The malonic acid diethyl ester and 1-butyl-3-methylimidazole were dispersed in ethanol to ensure uniform mixing. The reaction was first carried out in a 100 mL round-bottom flask at 25-35°C for 3-5 min. Then, octanal was slowly added dropwise, and the reaction was continued for 30-60 min. After the reaction was completed, the product, 2-decylidene-1,3-propanedioic acid diethyl ester, was obtained by extracting with diethyl ether for 3-4 times.

[0112] (2) The molar ratio of 2-decylidene-1,3-propanedioic acid diethyl ester, hydroxylamine hydrochloride, and NaOH was 1:2.3:4.5. The hydroxylamine hydrochloride and NaOH were separately dissolved in 40 mL of methanol and ultrasonically dispersed and dissolved. After mixing, the mixture was stirred in an ice water bath for 0.5-1.5 h to ensure the complete dissociation of hydroxylamine. Then, 2-decylidene-1,3-propanedioic acid diethyl ester was added, and the temperature was raised to 60°C for a reaction time of 4 h to obtain 2-decylidene-1,3-propanedioic acid diethyl ester sodium.

[0113] (3) 1.0 mol / L hydrochloric acid was used to adjust the pH of the solution to 5-6, and filtration was performed to obtain the crude product of 2-decylidene-1,3-propanedioic acid diethyl ester in the form of white solid. The crude product of 2-decylidene-1,3-propanedioic acid diethyl ester was dispersed in ethyl acetate, and the ethyl acetate was removed by filtration using a sand core funnel. After drying and grinding, the relatively pure product of 2-decylidene-1,3-propanedioic acid dihydroxamic acid (i.e., the collector) was obtained.

[0114] Comparative Example 1

[0115] The method for efficient flotation of ilmenite in this comparative example is the same as that in Example 1, except that no fucoidan was added.

[0116] Comparative Example 2

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

[0118] Comparative Example 3

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

[0120] Comparative Example 4

[0121] The ilmenite high-efficiency flotation method of the present 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 ilmenite high-efficiency flotation method of the present comparative example is the same as that of Example 1, except that the structure of the collector is as follows:

[0124]

[0125] Comparative Example 6

[0126] The ilmenite high-efficiency flotation method of the present comparative example is the same as that of 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 are respectively used for the flotation of ilmenite actual ore with a grade of 14.97%, and the pulp is 1.5 L. The flotation effects are shown in Table 1.

[0129] Table 1

[0130]

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

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

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

[0134] The results of Examples 1 and Comparative Examples 5-6 show that the collector used in the present application has good collecting effect and selectivity on ilmenite compared with the collectors in the prior art, and can realize 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 carry out flotation on ilmenite actual ore with a grade of 14.97%, and the pulp was 1.5L, and the TiO2 grade and recovery rate in the concentrate under different collector dosages were investigated, and the results are shown in Table 2.

[0137] Table 2

[0138]

[0139]

[0140] The TiO2 grade and recovery rate in the concentrate under different collector dosages were investigated, and the results show that the optimal dosage of the collector in the present application is 650g / t, and with the increase of the collector dosage, the yield of ilmenite concentrate increases, but the grade and recovery rate decrease, which shows that the dosage of the collector in the present application is lower. In addition, the collectors used in Comparative Examples 5 and 6 for flotation of ilmenite have not reached the flotation effect of the collector in the present application.

[0141] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this, any change or replacement that can be easily thought of by those skilled in the art within the technical range disclosed in the present application should be covered in the protection scope of the present application.

Claims

1. A method of high selectivity flotation of minerals, characterized in that, The method comprises the following steps: after the first microwave pretreatment of the raw ore slurry, adding fucoidan for the second microwave pretreatment, adding a collector for the first flotation to obtain a rough concentrate, and carrying out the second flotation on the rough concentrate to obtain the ilmenite concentrate. The chemical structure of the collector is shown as formula (I). In the formula, R is an alkyl group.

2. A process for the high selective flotation of minerals according to claim 1, characterized in that, The microwave power of the first microwave pretreatment is 400-800 W, and the treatment time is 1-5 min.

3. A process for the high selective flotation of minerals according to claim 1, characterized in that, Sulfuric acid is also added during the first and second flotations, and the pH of the slurry is 4-5 during the first flotation and 3-4 during the second flotation.

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

5. A method for the high selective flotation of a mineral according to any one of claims 1 to 3, characterised in that, The collector is prepared by the following method: (1) dissolving an ester compound and a catalyst in a dispersant, adding an aldehyde for substitution reaction to obtain an ester compound with a branched chain; (2) dissolving a hydroxylamine salt and a base in methanol, ultrasonic dispersion and dissolution, mixing for ice water bath free reaction, adding the ester compound with a branched chain, heating for hydroxamic acid reaction, adjusting pH, filtering, and drying to obtain the collector.

6. A process for the high selective flotation of minerals 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 hexaphosphoric acid, and 1-hexyl-3-methylimidazole hexaphosphoric acid. The dispersant is methanol or ethanol. The aldehyde is one of octyl aldehyde and decyl aldehyde.

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

4.

8. A process for the high selective flotation of minerals according to claim 5, characterized in that, In step (2), the hydroxylamine salt is one of hydroxylamine hydrochloride, hydroxylamine carbonate, and hydroxylamine sulfate.

9. A process for the high selective flotation of minerals according to claim 5, characterized in that, In step (2), the heating temperature is 30-60℃.

10. A process for the high selective flotation of minerals according to claim 5, characterized in that, In step (2), the molar ratio of the ester compound with a branched chain, the hydroxylamine salt, and the base is 1:2.2-2.3:4.4-4.5.

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