Application of amphoteric collecting agent AEDA-14 in iron ore flotation

Abstract

The invention belongs to the technical field of mineral separation, and particularly relates to application of an amphoteric collecting agent AEDA-14 in iron ore flotation. Aiming at the defects of an existing iron ore flotation reagent system in the aspects of foam behavior, hard water adaptability, pH and temperature stability, interface selectivity in a complex ion environment and the like, the invention provides an iron ore flotation process of an amphoteric collecting agent AEDA-14, and the iron ore flotation process still has good stability and selectivity under the conditions of wide pH and complex ions. The sensitivity to water quality, ion background and operation condition fluctuation in the iron ore flotation process is reduced as much as possible, and efficient and green separation of hematite and gangue minerals is achieved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of mineral processing, and particularly relates to application of an amphoteric collector AEDA-14 in iron ore flotation. BACKGROUND

[0002] In the process of iron ore flotation, a series of common problems exist in the conventional collector system: on the one hand, in the flotation operation, phenomena such as thick foam, high foam layer stability or difficulty in breaking, poor adaptability to hard water, high sensitivity to pH and temperature changes, and narrow process control window are prone to occur; on the other hand, for refractory iron ores such as hematite and iron-bearing silicates, the conventional fatty acid and amine collectors have low collection efficiency and insufficient selectivity for target minerals, and are easily affected by the competitive adsorption and covering effect of anions (such as CO3 2- , SO4 2- , etc.) and colloidal clay particles in the ore slurry, resulting in a decrease in the effective adsorption amount of the reagent, a decrease in the hydrophobicity of the mineral surface, and thus affecting the stability and improvement space of the flotation index.

[0003] Under the driving of the development demand of complex iron ore resources, amphoteric collectors have gradually become a research hotspot because they have both acidic and basic functional groups and are expected to maintain a certain interfacial activity and selectivity in a wide pH range in theory. However, most of the existing research results on amphoteric collectors still remain in the laboratory basic research or small-scale test stage, and the process application foundation is relatively weak. In the actual complex ore slurry environment, the structural stability and interfacial behavior of such collectors are easily affected by the combined effect of multivalent cations such as Mg 2+ , Al 3+ , high-concentration inorganic anions and colloidal particles, and phenomena such as competitive adsorption, complexation or aggregation occur, resulting in a decrease in the effective concentration and a decrease in the selectivity, and the collection efficiency and repeatability are difficult to meet the actual needs of the industrial separation process of complex iron ore.

[0004] In summary, the existing iron ore flotation reagent system has obvious deficiencies in aspects such as foam behavior, hard water adaptability, pH and temperature stability, and interfacial selectivity in a complex ion environment, especially when dealing with refractory iron ores containing a high content of MgO and rich in iron-bearing silicate gangue. Therefore, it is urgent to develop a flotation method and a matching amphoteric collector system that still has good stability and selectivity under wide pH and complex ion conditions, so that the iron ore flotation process can reduce the sensitivity to water quality, ion background and fluctuations in operating conditions as much as possible, and realize efficient and green separation of hematite and gangue minerals. SUMMARY

[0005] In view of the above problems, the application provides application of an amphoteric collector AEDA-14 in iron ore flotation.

[0006] The application of the amphoteric collector AEDA-14 in iron ore flotation includes the following contents: the amphoteric collector AEDA-14 can be used in open-circuit flotation and closed-circuit flotation of iron ore;

[0007] In open-circuit flotation: after the iron ore is ground into slurry and flotation, an inhibitor is added, then the amphoteric collector AEDA-14 is added, and the roughing operation is entered to obtain roughing concentrate and roughing tailings; the amphoteric collector AEDA-14 is added to the roughing concentrate, the cleaning operation is entered to obtain cleaning concentrate and cleaning tailings, and the cleaning concentrate is the iron concentrate product; the amphoteric collector AEDA-14 is added to the roughing tailings, the scavenging operation is entered to obtain scavenging froth product and scavenging tailings, and the scavenging tailings are the final tailings;

[0008] When entering the roughing operation, the addition amount of the inhibitor is 50g / t~150g / t, and the addition amount of the amphoteric collector AEDA-14 is 100g / t~200g / t; when entering the cleaning operation, the addition amount of the amphoteric collector AEDA-14 is 50g / t~100g / t; when entering the scavenging operation, the addition amount of the amphoteric collector AEDA-14 is 100g / t~200g / t, and three-stage scavenging operation is carried out.

[0009] In closed-circuit flotation: after the iron ore is ground into slurry and flotation, an inhibitor is added, then the amphoteric collector AEDA-14 is added, and the roughing operation is entered to obtain roughing concentrate and roughing tailings; the amphoteric collector AEDA-14 is added to the roughing concentrate, the cleaning operation is entered to obtain cleaning concentrate and cleaning tailings, and the cleaning concentrate is the final iron concentrate product, and the cleaning tailings return to the previous operation; the amphoteric collector AEDA-14 is added to the roughing tailings, the scavenging operation is entered to obtain scavenging froth product and scavenging tailings, the scavenging froth product returns to the previous operation, and the scavenging tailings are the final tailings;

[0010] When entering the roughing operation, the addition amount of the inhibitor is 50g / t~100g / t, and the addition amount of the amphoteric collector AEDA-14 is 120g / t~160g / t; when entering the cleaning operation, the addition amount of the amphoteric collector AEDA-14 is 60g / t~80g / t; when entering the scavenging operation, the addition amount of the amphoteric collector AEDA-14 is 30g / t~150g / t, and three-stage scavenging operation is carried out.

[0011] The amphoteric collector AEDA-14 is HOOC-CH(NH-CH2-CH2-NH2)-(CH2) 11-CH3, containing a hydrophobic alkyl chain, a carboxylic acid group and an amine group, in the process of iron ore flotation, the hydrophobic alkyl chain forms a metal-carboxylate bond on the surface of the mineral, and the amine group has electrostatic interaction and hydrogen bond with the negatively charged oxygen-containing group on the surface of the mineral, so that the amphoteric collector simultaneously exhibits anionic and cationic collector characteristics, and forms a stable adsorption layer on the surface of the iron ore; the structural formula is as follows: .

[0012] The following conditions are met in open-circuit flotation and closed-circuit flotation:

[0013] After the iron ore is ground, the particle size is 200-400 mesh, and the pulp concentration is 15-35 wt%; the flotation temperature is 10-30 DEG C, preferably 15-30 DEG C; during the flotation process, NaOH or HCl is used to adjust the pulp pH to 3-11, preferably 8-11;

[0014] The order of adding the reagents is: first, add the depressant and stir for 1-5 min to mix, then add the amphoteric collector AEDA-14 and stir for 2-4 min to mix, to ensure that the reagents are fully dispersed and adsorbed in the raw ore pulp before entering the roughing operation; the time for each flotation operation is 2-5 min;

[0015] The amphoteric collector AEDA-14 can resist the interference of multivalent ions such as Mg 2+ , Al 3+ , and the interference of pH fluctuation (pH is 3-11); the depressant includes starch derivatives and polysaccharides such as L-carrageenan and locust bean gum.

[0016] The beneficial effects of the present application are as follows:

[0017] The present application uses the amphoteric collector AEDA-14 for iron ore flotation, which has outstanding application effect in the complex system of iron ore-silicate intergrowth, can realize efficient separation of hematite, reduce reagent consumption, and improve concentrate grade and recovery rate. Compared with traditional oleate or single amine collector, the amphoteric collector AEDA-14 of the present application has wider adaptability and better separation index, and can achieve higher recovery rate and better concentrate grade in the dosage range of 10-40 mg / L. At the same time, the solubility of the collector is better than that of dodecylamine, thereby giving it stronger interface adaptability and application potential. Under the conditions of mixed ore flotation of pure iron ore and pure silicate mineral (pulp concentration 20-35%, pH 7-9, temperature 20-25 DEG C), the use of AEDA-14 can obtain hematite concentrate with a grade of ≥65% and a recovery rate of ≥87%. Compared with sodium oleate or single amine collector, the concentrate grade is increased by about 2-4 percentage points, and the recovery rate is increased by about 3-5 percentage points. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 Flotation flow chart for pure mineral in Example 1;

[0019] Figure 2 Flotation flow chart for Al 3+ Flotation effect diagram of dosage of amphoteric collector AEDA-14;

[0020] Figure 3 Flotation flow chart for Mg 2+ Flotation effect diagram of dosage of amphoteric collector AEDA-14;

[0021] Figure 4 Flotation effect diagram of pH of amphoteric collector AEDA-14 when no activating ion is added in Example 2;

[0022] Figure 5 Flotation flow chart for Al 3+ Flotation effect diagram of pH of amphoteric collector AEDA-14 when activating ion exists;

[0023] Figure 6 Flotation flow chart for Mg 2+ Flotation effect diagram of pH of amphoteric collector AEDA-14 when activating ion exists;

[0024] Figure 7 Flotation flow chart for mixed mineral in Example 3;

[0025] Figure 8 Flotation flow chart for open-circuit test in Example 4;

[0026] Figure 9 Flotation flow chart for closed-circuit test in Example 6. DETAILED DESCRIPTION

[0027] The technical solutions of the present application will be described clearly and completely in combination with the embodiments and the drawings. It should be noted that the embodiments described in the present application are only used to further explain and illustrate, but not to limit the application scope. Based on the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0028] Example 1

[0029] Pure mineral flotation tests were carried out respectively with pure iron ore and pure silicate ore.

[0030] S1: pure iron ore (purity 99.8%) was taken as the research object to carry out flotation test, and the flotation flow chart is shown in Figure 1 .

[0031] Pure iron ore was ground to a particle size of 200-400 mesh to prepare pure iron ore slurry. Single mineral tests were conducted under the conditions of slurry concentration of 35%, flotation temperature of room temperature, AEDA-14 dosage of 30 mg / L, and pH of 7. The iron ore recovery rate was 99.94% according to the single mineral test.

[0032] S2: Flotation tests were conducted using pure silicate minerals (purity 85%~90%) as the research object. The pure silicate minerals were ground to a particle size of 200-400 mesh to prepare a slurry. Flotation tests were performed under the following conditions: slurry concentration of 35%, flotation temperature at room temperature, AEDA-14 dosage of 30 mg / L, and pH of 9. The results showed that the concentrate recovery rate of the pure silicate minerals was 92.35%.

[0033] Example 2

[0034] Using pure hematite, type I silicate minerals, and type II silicate minerals as research objects, under conditions of 35% slurry concentration and room temperature, and with a fixed AEDA-14 addition of 30 mg / L, the effects of different activator ions (Mg) were investigated. 2+ Al 3 + The effects of pH conditions on the flotation performance of AEDA-14 amphoteric collector were investigated.

[0035] Al 3+ The effect of dosage on the floatability of the three types of minerals, such as Figure 2 As shown, Al 3+ When added at concentrations of 10 mg / L, 20 mg / L, 40 mg / L, 60 mg / L, 80 mg / L, and 100 mg / L, the recoveries of hematite and two types of silicate minerals were ≥90%, and the recoveries of one type of silicate mineral were ≥70%. Mg 2+ The effect of dosage on the floatability of the three types of minerals is as follows: Figure 3 As shown, Mg 2+ When the added amounts are 10 mg / L, 20 mg / L, 40 mg / L, 60 mg / L, 80 mg / L, and 100 mg / L, the recovery rates of hematite and type 2 silicate minerals are ≥90%, and the recovery rate of type 1 silicate minerals is ≥80%.

[0036] The effect of pH on flotation without the addition of activating ions is as follows: Figure 4 As shown, the recoveries of hematite and its two silicate minerals were ≥80% at pH values ​​of 3, 5, 7, 9, and 11. Al 3+ The effect of pH on flotation when the addition amount is 60 mg / L is as follows: Figure 5 As shown, at pH values ​​of 3, 5, 7, 9, and 11, the recoveries of hematite and the two types of silicate minerals were ≥73%. Mg 2+The effect of pH on flotation when the addition amount is 60 mg / L is as follows: Figure 6 As shown, the recovery rates of hematite and the two types of silicate minerals were ≥89% at pH values ​​of 3, 5, 7, 9, and 11.

[0037] The experimental results show that under acidic conditions, the activator ions have only a slight effect on the surface properties of minerals and the adsorption behavior of the collector, while under neutral and alkaline conditions, they show almost no significant effect. This indicates that the amphoteric collector AEDA-14 can maintain high interfacial stability and selectivity under different slurry conditions, is not easily affected by external ion concentration and pH fluctuations, and has good adaptability and system stability.

[0038] Example 3

[0039] A mixed ore of pure iron ore (99.8% purity) and a class of pure silicate minerals (85%–90% purity) was used as the research object. Modified starch was used as an inhibitor, and AEDA-14 was used as the collector for flotation experiments. The flotation process is as follows: Figure 7 As shown.

[0040] The iron grade in the mixed ore was 38.12%. The mixed ore was ground to a particle size of 200-400 mesh to prepare a mixed ore slurry. A binary mixed mineral test was conducted under the conditions of slurry concentration of 35%, flotation temperature of room temperature, modified starch dosage of 3 mg / L, AEDA-14 dosage of 30 mg / L, and pH of 9. The test results showed that the iron grade in the concentrate was 66.45% with a recovery rate of 87.59%; the iron grade in the tailings was 9.51% with a recovery rate of 12.41%.

[0041] Example 4

[0042] An open-circuit test was conducted using an actual hematite ore sample (from a mine in Lüliang City, Shanxi Province) as the research object.

[0043] The actual ore sample had an iron grade of 48.97% and a SiO2 content of 35%. The actual ore sample was ground to a particle size of 200-400 mesh to prepare an actual ore sample slurry. The slurry concentration was adjusted to 27% and the pH to 9. The flotation open-circuit test was carried out at room temperature. Add 100 g / t of inhibitor-modified starch and 140 g / t of amphoteric collector AEDA-14 to the slurry, and proceed to the roughing operation to obtain roughing concentrate and roughing tailings. Add 70 g / t of amphoteric collector AEDA-14 to the roughing concentrate, adjust the pH to 9, and proceed to the cleaning operation to obtain cleaned concentrate and cleaned tailings. Add 70 g / t of amphoteric collector AEDA-14 to the roughing tailings, adjust the slurry pH to 9, and proceed to the scavenging operation, sequentially going through three stages: scavenging I, scavenging II, and scavenging III. After scavenging I, the roughing tailings yield scavenging I froth product (scavenging concentrate 1) and scavenging I tailings. Add 35 g / t of amphoteric collector AEDA-14 to the scavenging I tailings, adjust the pH to 9, and proceed to scavenging II to obtain scavenging II froth product (scavenging concentrate 2) and scavenging II tailings. Add amphoteric collector AEDA-14 to the scavenging II tailings. After adjusting the pH to 9, the material is fed into the scavenging stage III, yielding scavenging stage III froth product (scavenger concentrate 3) and scavenging stage III tailings. The flotation process is as follows: Figure 8 As shown.

[0044] After the above flotation operation, the iron grade in the concentrate was 66.35% and the recovery rate was 76.16%, while the iron grade in the tailings of the scavenging III process was 3.23% and the recovery rate was 1.08%.

[0045] Example 5

[0046] An open-circuit test was conducted using an actual hematite ore sample (from a mine in Lüliang City, Shanxi Province). Unlike Example 4, the pH was changed. The actual ore sample had an iron grade of 48.97% and a SiO2 content of 35%. The sample was ground to a particle size of 200-400 mesh to prepare an actual ore slurry. The slurry concentration was adjusted to 27%, and the pH to 11. An open-circuit flotation test was then conducted at room temperature. Add 100 g / t of inhibitor-modified starch and 140 g / t of amphoteric collector AEDA-14 to the slurry, then proceed to the roughing operation to obtain roughing concentrate and roughing tailings. Add 70 g / t of amphoteric collector AEDA-14 to the roughing concentrate, adjust the pH to 11, and then proceed to the cleaning operation to obtain cleaned concentrate and cleaned tailings. Add 70 g / t of amphoteric collector AEDA-14 to the roughing tailings, adjust the slurry pH to 11, and then proceed to the scavenging operation, sequentially going through three stages: scavenging I, scavenging II, and scavenging III. After scavenging I, the roughing tailings yield scavenging I froth product and scavenging I tailings. Add 35 g / t of amphoteric collector AEDA-14 to the scavenging I tailings, adjust the pH to 11, and then proceed to scavenging II to obtain scavenging II froth product and scavenging II tailings. Add amphoteric collector AEDA-14 to the scavenging II tailings. After adjusting the pH to 11, the product is fed into the scavenging III process to obtain scavenging III foam product and scavenging III tailings.

[0047] After the above flotation operations, the iron grade in the concentrate was 65.32%, with a recovery rate of 74.98%, while the iron grade in the tailings from the scavenging stage III was 4.47%, with a recovery rate of 1.5%. Based on the results of the open-circuit test, the actual ore samples were subjected to flotation operations consisting of one roughing stage, one cleaning stage, and three scavenging stages.

[0048] Example 6

[0049] A closed-circuit test was conducted using an actual ore sample (a mine in Lüliang City, Shanxi Province) as the research object (the raw ore had an iron grade of 48.97% and a SiO2 content of 35%). The process included roughing, cleaning and three-stage scavenging operations to form a slurry circulation loop, which was used to achieve effective separation of target minerals and gangue minerals.

[0050] Hematite is ground to a fineness of 200-400 mesh to prepare a slurry with a concentration of 27%. A pH adjuster is added to control the pH of the slurry, adjusting it to 9. Then, 80 g / t of modified starch and 120 g / t of amphoteric collector AEDA-14 are added sequentially to condition the slurry. The conditioned slurry then enters the roughing stage. In the roughing stage, the slurry undergoes a first flotation to obtain roughing concentrate and roughing tailings. 60 g / t of amphoteric collector AEDA-14 is added to the roughing concentrate, and the pH is adjusted to 9 before it enters the cleaning stage to remove gangue inclusions, yielding cleaned concentrate and cleaned tailings. The cleaned concentrate is the high-grade iron concentrate product, while the cleaned tailings are returned to the roughing or scavenging circuit to improve the recovery rate. The roughing tailings undergo three stages: scavenging I, scavenging II, and scavenging III. After adding 60 g / t of amphoteric collector AEDA-14 and adjusting the pH to 9, the roughing tailings are processed through scavenging I to obtain scavenging I tailings and scavenging I froth product. The scavenging I froth product is returned to the roughing stage. Then, 30 g / t of amphoteric collector AEDA-14 is added to the scavenging I tailings, and the pH is adjusted to 9 before entering scavenging II to obtain scavenging II tailings and scavenging II froth product. The scavenging II froth product is returned to scavenging I. Finally, 15 g / t of amphoteric collector AEDA-14 is added to the scavenging II tailings, and the pH is adjusted to 9 before entering scavenging III to obtain scavenging III tailings and scavenging III froth product. The scavenging III froth product is returned to scavenging II, and the scavenging III tailings are the final tailings discharged from the system. The flotation process is as follows: Figure 9 As shown.

[0051] Through multi-stage scavenging-reflux circulation, the unfloated slurry is reused in multiple loops, ensuring full recovery of valuable components and reducing reagent consumption. Under the above conditions, the iron concentrate product has an iron grade of 66.75% and an iron recovery rate of 88.75%; the final tailings have an iron grade of 15.79% and an iron recovery rate of 11.25%.

Claims

1. The application of an amphoteric collector, AEDA-14, in iron ore flotation, characterized in that, The amphoteric collector is used in open-circuit or closed-circuit flotation of iron ore, and its structural formula is as follows: ； In open-circuit flotation: after iron ore is ground into a slurry, it is subjected to flotation. An inhibitor and the aforementioned amphoteric collector are added, and the mixture enters the roughing operation to obtain a roughing concentrate and roughing tailings. The amphoteric collector is added to the roughing concentrate, and the mixture enters the cleaning operation to obtain a cleaned concentrate and cleaned tailings. The cleaned concentrate is the iron concentrate product. The amphoteric collector is added to the roughing tailings, and the mixture enters the scavenging operation to obtain a scavenging froth product and scavenging tailings. The scavenging tailings are the final tailings. In closed-circuit flotation: after iron ore is ground into a slurry, it is subjected to flotation. Depressants and the aforementioned amphoteric collector are added, and the slurry enters the roughing operation to obtain roughing concentrate and roughing tailings. The amphoteric collector is added to the roughing concentrate, and the slurry enters the cleaning operation to obtain cleaning concentrate and cleaning tailings. The cleaning concentrate is the final iron concentrate product, and the cleaning tailings are returned to the previous stage operation. The amphoteric collector is added to the roughing tailings, and the scavenging operation is conducted to obtain scavenging froth product and scavenging tailings. The scavenging froth product is returned to the previous stage operation, and the scavenging tailings are the final tailings.

2. The application of the amphoteric collector AEDA-14 according to claim 1 in iron ore flotation, characterized in that, The amphoteric collector contains hydrophobic alkyl chains, carboxylic acid groups, and amino functional groups. During iron ore flotation, it exhibits both anionic and cationic collector characteristics, forming a stable adsorption layer on the iron ore surface.

3. The application of the amphoteric collector AEDA-14 according to claim 1 in iron ore flotation, characterized in that, During open-circuit flotation: when entering the roughing operation, the amount of the inhibitor added is 50g / t~150g / t, and the amount of the amphoteric collector added is 100g / t~200g / t; when entering the cleaning operation, the amount of the amphoteric collector added is 50g / t~100g / t; when entering the scavenging operation, the amount of the amphoteric collector added is 100g / t~200g / t, and a three-stage scavenging operation is carried out.

4. The application of the amphoteric collector AEDA-14 according to claim 1 in iron ore flotation, characterized in that, During closed-circuit flotation: when entering the roughing operation, the amount of the inhibitor added is 50g / t~100g / t, and the amount of the amphoteric collector added is 120g / t~160g / t; when entering the cleaning operation, the amount of the amphoteric collector added is 60g / t~80g / t; when entering the scavenging operation, the amount of the amphoteric collector added is 30g / t~150g / t, and a three-stage scavenging operation is carried out.

5. The application of the amphoteric collector AEDA-14 according to claim 1 in iron ore flotation, characterized in that, The conditions for both open-circuit and closed-circuit flotation are as follows: the iron ore is ground to a particle size of 200-400 mesh, the pulp concentration during flotation is 15%-35wt%, and the flotation temperature is 10℃-30℃.

6. The application of the amphoteric collector AEDA-14 according to claim 1 in iron ore flotation, characterized in that, The pH of the pulp is 3-11 in both open-circuit and closed-circuit flotation.

7. The application of the amphoteric collector AEDA-14 according to claim 6 in iron ore flotation, characterized in that, The pulp pH is 8-11 for both open-circuit and closed-circuit flotation.

8. The application of the amphoteric collector AEDA-14 according to claim 1 in iron ore flotation, characterized in that, The amphoteric collector is resistant to Mg in both open-circuit and closed-circuit flotation. 2+ Al 3+ Interference from ions and pH fluctuations.

9. The application of the amphoteric collector AEDA-14 according to claim 1 in iron ore flotation, characterized in that, The inhibitors used in both open-circuit and closed-circuit flotation include starch derivatives, gum arabic, L-carrageenan, and carob gum.

10. The application of the amphoteric collector AEDA-14 according to claim 1 in iron ore flotation, characterized in that, In both open-circuit and closed-circuit flotation, the inhibitor is first added and stirred for 2 to 5 minutes to mix evenly, and then the amphoteric collector is added and stirred for 2 to 5 minutes to mix evenly, so that the reagent is fully dispersed and adsorbed before entering the roughing operation; the time for each flotation operation is 2 to 5 minutes.

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