A combined depressant for flotation separation of fluorite and calcium-containing gangue minerals and application thereof

Abstract

The application discloses a combined depressor for flotation separation of fluorite and calcium-containing gangue minerals and application thereof. The combined depressor is composed of water glass, iminodisuccinic acid and carboxymethyl cellulose, and mass percentages of the components of the combined depressor are as follows: water glass 60-75%, iminodisuccinic acid 15-30% and carboxymethyl cellulose 10-25%. The application also provides a method for applying the combined depressor, which specifically comprises the following steps: firstly, grinding the ore sample; adjusting the fluorite ore slurry to a required slurry concentration and pH value, adding the combined depressor, and performing one rough separation to obtain fluorite rough concentrate and calcium-containing gangue tailings; then, performing seven times of cleaning to obtain final fluorite concentrate product; and performing two times of scavenging to obtain fluorite tailings. The combined depressor is clean, efficient and pollution-free, tailings slurry is easy to handle, and the combined depressor can efficiently realize the flotation separation of fluorite and calcium-containing gangue minerals, so the combined depressor has a wide application prospect.

Description

Technical Field

[0001] This invention relates to a combined inhibitor for the flotation separation of fluorite and calcium-containing gangue minerals and its application, belonging to the field of mineral processing flotation technology. Background Technology

[0002] Fluorite is an important source of elemental fluorine. In nature, fluorite often coexists with calcium-bearing gangue minerals such as calcite and dolomite. Flotation is the most important and efficient method for processing and enriching fluorite ore. Fluorite ore and calcium-bearing gangue minerals such as calcite and dolomite belong to the same calcareous minerals. They have similar surface chemical properties, solution chemical properties and the same calcium ion active sites. When using traditional fatty acid collectors for flotation, their floatability is similar and it is difficult to separate them. Therefore, the development, selection and application of efficient flotation separation inhibitors are crucial.

[0003] Currently, the most widely used depressant in the flotation separation of fluorite and calcium-bearing gangue minerals is still the traditional water glass depressant. During flotation, large quantities of water glass are used, but its selective inhibition effect is poor. Adding large amounts of water glass also leads to highly dispersed tailings, making settling difficult and causing significant challenges in wastewater treatment. Furthermore, with the continuous development and utilization of fluorite, the ore is becoming increasingly lean, fine, and complex, making the effectiveness of a single water glass depressant increasingly diminished, hindering efficient flotation separation of fluorite.

[0004] Iminodisuccinic acid is a novel, environmentally friendly chelating agent that is highly water-soluble and readily biodegradable. Its hydrophilic carboxyl groups can both adsorb onto the surface of calcium-bearing minerals and act as inhibitors. Carboxymethyl cellulose is widely available and abundant, soluble in water, and commonly used as an inhibitor in mineral processing. Therefore, developing green, low-cost, and efficient combined inhibitors for calcium-bearing gangue minerals in the efficient flotation separation of fluorite is a future trend in fluorite beneficiation and is of great significance for improving the utilization rate of fluorite resources in my country. Summary of the Invention

[0005] To address the difficulty in separating fluorite from calcareous gangue minerals such as calcite, apatite, and dolomite during flotation, the present invention aims to provide a combined inhibitor for the flotation separation of fluorite and calcareous gangue minerals, and its application, to solve the problem of difficult separation of fluorite from calcareous gangue minerals during flotation.

[0006] The combined inhibitors for the flotation separation of fluorite and calcium-containing gangue minerals described in this invention include water glass, iminodisuccinic acid, and carboxymethyl cellulose.

[0007] Preferably, the combined inhibitor for the flotation separation of fluorite and calcium-containing gangue minerals contains 60%–75% water glass, 15%–30% iminodisuccinic acid, and 10%–25% carboxymethyl cellulose, with a total mass percentage of 100% for water glass, iminodisuccinic acid, and carboxymethyl cellulose.

[0008] The present invention also provides the application of a combined inhibitor for the flotation separation of fluorite and calcareous gangue minerals.

[0009] Preferably, fluorite concentrate and fluorite tailings are obtained from fluorite ore by flotation separation through a process of one roughing, seven cleaning, and two scavenging.

[0010] Preferably, a combination inhibitor is added in one coarse selection and seven fine selection processes, but no combination inhibitor is added in other processes.

[0011] Preferably, the amount of combined inhibitor added during the roughing process is 450–750 g / t; during the seven refining processes, the amount of combined inhibitor added during refining I and refining II is 150–250 g / t, the amount of combined inhibitor added during refining III, refining IV and refining V is 50–84 g / t, and the amount of combined inhibitor added during refining VI and refining VII is 16–28 g / t.

[0012] Preferably, the combination inhibitor is first dissolved in ultrapure water before use. The specific preparation method is as follows: water glass, iminodisuccinic acid and carboxymethyl cellulose are added to ultrapure water at the same time, and the mixture is heated and stirred vigorously to obtain the inhibitor aqueous solution.

[0013] Preferably, the total mass concentration of the three substances—water glass, iminodisuccinic acid, and carboxymethyl cellulose—in the aqueous solution of the inhibitor is 15% to 20%, and the concentration of the combined inhibitor is diluted to 1% to 2% before use in flotation.

[0014] Preferably, the heating temperature is 60℃~70℃ and the stirring intensity is 1200~1500r / min.

[0015] Preferably, the specific process flow for flotation separation is as follows:

[0016] (1) Grind the ore sample and adjust the slurry to the required slurry concentration and pH value.

[0017] (2) Fluorite roughing: Add a combination inhibitor to the slurry obtained in step (1), stir, add a collector, stir, and float to obtain fluorite rough concentrate and calcium gangue tailings.

[0018] (3) Fluorite scavenging: Fluorite scavenging is performed on the calcium-bearing gangue tailings obtained in step (2). In scavenging I, a collector is added, stirred, and floated. In scavenging II, a collector is added, stirred, and floated to obtain the final fluorite tailings.

[0019] (4) Fluorite Refinement: Fluorite refinement is carried out on the rough concentrate obtained in step (2). The steps of refinement I to refinement VII are as follows: add combined inhibitor, stir, float, and obtain the final fluorite concentrate.

[0020] Preferably, in step (1), the grinding fineness meets the requirement that -0.074 mm accounts for 70-80%.

[0021] Preferably, in step (1), the slurry concentration is 25-35%, the slurry pH is 9-11, the adjuster is one or two of sodium hydroxide and sodium carbonate in any proportion, and the slurry conditioning time is 2-3 min.

[0022] Preferably, in step (2), the amount of combined inhibitor added in the roughing of fluorite is 450-750 g / t, and the amount of collector added is 500-750 g / t; the stirring time is 2-3 min and the flotation time is 4-5 min.

[0023] Preferably, in step (3), the amount of collector added in scavenging I is 180-250 g / t; the amount of collector added in scavenging II is 60-150 g / t; the stirring time for both scavenging I and scavenging II is 2-3 min, the flotation time for scavenging I is 3-4 min, and the flotation time for scavenging II is 2.5-3.5 min.

[0024] Preferably, in step (4), the amount of combined inhibitor added in Selected I and Selected II is 150-250 g / t, the stirring time is 2-3 min, and the flotation time is 2-3 min; the amount of combined inhibitor added in Selected III, Selected IV and Selected V is 50-84 g / t, the stirring time is 2-3 min, and the flotation time is 2-3 min; and the amount of combined inhibitor added in Selected VI and Selected VII is 16-28 g / t, the stirring time is 2-3 min, and the flotation time is 2-3 min.

[0025] The collectors used in the flotation separation process are common collectors used in flotation separation.

[0026] The principle of this invention: Water glass is a commonly used flotation depressant for calcium-bearing gangue minerals, but its use is limited by drawbacks such as weak selectivity, the need for acidification treatment, and the difficulty in treating mineral processing wastewater. Therefore, it has limitations in actual production. The molecular formula of iminodisuccinic acid is C8H. 11 O8N, structural formula is This compound contains a large number of polar carboxyl groups, which can selectively adsorb onto the surface of calcium-bearing gangue minerals, thus inhibiting their growth. Carboxymethyl cellulose (CMC) is a soluble natural polymer that acts as an inhibitor of calcium-bearing gangue minerals in the slurry solution. It also acts as a dispersant, helping to disperse the slurry and facilitating the adsorption of flotation reagents on the mineral surface. A novel compound was synthesized by heating and mixing iminodisuccinic acid, water glass, and CMC. Water glass facilitates adsorption of the reagents onto the slurry particles. Iminodisuccinic acid exhibits good selectivity, and its four carboxyl groups can stably adsorb onto the calcium sites of calcium-bearing gangue minerals. Carboxymethyl cellulose makes the mineral particles more hydrophilic. This new compound exerts a synergistic inhibitory effect on the surface of calcium-bearing gangue minerals.

[0027] Beneficial effects of the present invention

[0028] (1) This invention proposes for the first time to combine inorganic inhibitor water glass with organic small molecule inhibitor iminodisuccinic acid and organic macromolecule inhibitor carboxymethyl cellulose as a combined inhibitor for the flotation separation of fluorite and calcium gangue minerals. Its application in fluorite flotation has not yet been reported.

[0029] (2) The combined suppression in this invention is applied to fluorite flotation to achieve efficient flotation separation of fluorite and calcium-containing gangue minerals, thereby obtaining high-grade fluorite concentrate, reducing the amount of flotation reagents, and improving separation efficiency.

[0030] (3) The components of the combined inhibitor in this invention are widely available, have good environmental properties, are easy to prepare, and are easy to operate and implement, which can effectively improve the flotation separation effect. Attached Figure Description

[0031] Figure 1 The above are flowcharts of the fluorite flotation process for both examples and comparative examples. Detailed Implementation

[0032] The technical solution of the present invention will be further described below with reference to the accompanying drawings and specific embodiments. However, the following embodiments are merely simple examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention is determined by the claims.

[0033] Example 1

[0034] In this embodiment, the mass percentages of water glass, iminodisuccinic acid, and carboxymethyl cellulose in the combined inhibition components are 70%, 15%, and 15%, respectively, and the collector is an aqueous solution of sodium oleate.

[0035] A fluorite mine in Hunan Province is a calcite-type fluorite-symbiotic deposit. The fluorite content in the raw ore is 31.43%, and the gangue minerals mainly include calcite, quartz, and feldspar, with calcite content at 20.46% and SiO2 content at 17.32%. A closed-circuit test process with one rougher, seven cleaners, two scavengers, and sequential return of middlings is adopted. The flotation separation process in this embodiment is as follows: Figure 1 As shown in Table 1, the flotation results are as follows: The specific steps and experimental conditions are as follows:

[0036] (1) Grind the raw ore to a fineness of -0.074 mm, accounting for 75%, adjust the slurry concentration to 25%, and adjust the slurry pH to 8.5 with sodium carbonate pH adjuster.

[0037] (2) Fluorite roughing: Add a combination inhibitor at a dosage of 600 g / t, mix the slurry for 2 min, add a collector sodium oleate at a dosage of 500 g / t, mix the slurry for 2 min; roughing flotation time is 4 min; finally, roughing concentrate and roughing tailings are obtained.

[0038] (3) Fluorite scavenging is performed on the obtained rough tailings: Scavenging I: Sodium oleate collector is added at a dosage of 200 g / t, stirred for 2 min, and floated for 3 min; Scavenging II: Sodium oleate collector is added at a dosage of 100 g / t, stirred for 2 min, and floated for 3 min; the final fluorite tailings are obtained.

[0039] (4) Fluorite refining of the obtained rough concentrate: Refining I and Refining II: Add combined inhibitor at a dosage of 200 g / t, stir for 2 min, and float for 3 min; Refining III, Refining IV and Refining V: Add combined inhibitor at a dosage of 60 g / t, stir for 2 min, and float for 2 min; Refining VI and Refining VII: Add combined inhibitor at a dosage of 20 g / t, stir for 2 min, and float for 2 min to obtain the final fluorite concentrate.

[0040] Comparative Example 1

[0041] The process flow of this comparative example is the same as that of the example. The difference between this comparative example and Example 1 is that the inhibitor used is a single water glass. The flotation results are shown in Table 1. The specific operation steps are as follows:

[0042] The pulp pH was adjusted to 8.5. During the fluorite roughing process, water glass was used as the depressant at a dosage of 600 g / t. In the fluorite finishing process: for Finishing I and Finishing II, the dosage of water glass was 200 g / t; for Finishing III, Finishing IV, and Finishing V, the dosage was 60 g / t; and for Finishing VI and Finishing VII, the dosage was 20 g / t. The types of reagents added, stirring time, reagent dosage, flotation time, and other parameters were the same as in Example 1.

[0043] Comparative Example 2

[0044] The process flow of this comparative example is the same as that of the example. The difference between this comparative example and Example 1 is that the inhibitor used is a single organic inhibitor, iminodisuccinic acid. The flotation results are shown in Table 1. The specific operation steps are as follows:

[0045] The pulp pH was adjusted to 8.5. During the fluorite roughing process, a single organic inhibitor, iminodisuccinic acid, was used at a dosage of 600 g / t. In the fluorite finishing process: for Finishing I and Finishing II, the dosage of iminodisuccinic acid was 200 g / t; for Finishing III, Finishing IV, and Finishing V, the dosage was 60 g / t; and for Finishing VI and Finishing VII, the dosage was 20 g / t. The types of reagents added, stirring time, reagent dosage, flotation time, and other parameters were the same as in Example 1.

[0046] Comparative Example 3

[0047] The process flow of this comparative example is the same as that of the example. The difference between this comparative example and Example 1 is that the inhibitor used is a single inhibitor, carboxymethyl cellulose. The flotation results are shown in Table 1. The specific operation steps are as follows:

[0048] The pulp pH was adjusted to 8.5. During the fluorite roughing process, a single carboxymethyl cellulose (CMC) inhibitor was used at a dosage of 600 g / t. In the fluorite finishing process: for Finishing I and Finishing II, the CMC inhibitor dosage was 200 g / t; for Finishing III, Finishing IV, and Finishing V, the CMC inhibitor dosage was 60 g / t; and for Finishing VI and Finishing VII, the CMC inhibitor dosage was 20 g / t. The other reagent types, stirring times, reagent dosages, flotation times, and flotation times were the same as in Example 1.

[0049] Table 1. Results of the full-process closed-loop test of Example 1 and Comparative Examples 1-3

[0050]

[0051] As shown in Table 1, under the same flotation process, flotation collector, flotation pulp concentration, and flotation pH, compared with single inorganic flotation depressants such as water glass, carboxymethyl cellulose, and iminodisuccinic acid, the combined depressant (water glass, iminodisuccinic acid, and carboxymethyl cellulose at mass percentages of 70%, 15%, and 15%) achieves higher CaF2 grade and CaF2 recovery, with values ​​of 95.42% and 72.81%, respectively. This indicates that the combined depressant described in this invention is an excellent flotation depressant for calcareous gangue minerals in the flotation of fluorite ore.

[0052] Example 2

[0053] In this embodiment, the mass percentages of water glass, iminodisuccinic acid, and carboxymethyl cellulose in the components of the combined inhibitor are 65%, 25%, and 10%, respectively, and the collector is an aqueous solution of sodium oleate.

[0054] A high-calcium fluorite mine in Inner Mongolia Autonomous Region has a fluorite content of 21.63% in its raw ore. The gangue minerals mainly include calcite, quartz, and mica, while the main metallic minerals are pyrite and other sulfide minerals. The calcite content is as high as 31.49%, and the SiO2 content is 18.36%. The flotation process also adopts a closed-circuit test process with one rougher, seven cleaners, two scavengers, and sequential return of middlings. The flotation separation process in this embodiment is also as follows... Figure 1 As shown in Table 2, the flotation results are as follows: The specific steps and experimental conditions are as follows:

[0055] (1) Grind the raw ore to a fineness of -0.074 mm, accounting for 75%, adjust the slurry concentration to 30%, and adjust the slurry pH to 9 with sodium carbonate as a pH adjuster.

[0056] (2) Fluorite roughing: Add a combination inhibitor at a dosage of 750 g / t, mix the slurry for 2 min, add a collector sodium oleate at a dosage of 600 g / t, mix the slurry for 2 min; roughing flotation time is 4 min; finally, roughing concentrate and roughing tailings are obtained.

[0057] (3) Fluorite scavenging is performed on the obtained rough tailings: Scavenging I: Sodium oleate collector is added at a dosage of 300 g / t, stirred for 2 min, and floated for 3 min; Scavenging II: Sodium oleate collector is added at a dosage of 150 g / t, stirred for 2 min, and floated for 3 min; the final fluorite tailings are obtained.

[0058] (4) Fluorite refining of the obtained rough concentrate: Refining I and Refining II: Add combined inhibitor at a dosage of 250 g / t, stir for 2 min, and float for 3 min; Refining III, Refining IV and Refining V: Add combined inhibitor at a dosage of 80 g / t, stir for 2 min, and float for 2 min; Refining VI and Refining VII: Add combined inhibitor at a dosage of 25 g / t, stir for 2 min, and float for 2 min to obtain the final fluorite concentrate.

[0059] Comparative Example 4

[0060] The process flow of this comparative example is the same as that of Example 2. For comparison, the difference between this comparative example and Example 2 is that the inhibitor used is a single water glass. The flotation results are shown in Table 2. The specific operation steps are as follows:

[0061] The pulp pH was adjusted to 9. During the fluorite roughing process, water glass was used as the depressant at a dosage of 750 g / t. In the fluorite finishing process: for Finishing I and Finishing II, the dosage of water glass was 250 g / t; for Finishing III, Finishing IV, and Finishing V, the dosage was 80 g / t; and for Finishing VI and Finishing VII, the dosage was 25 g / t. The types of reagents added, stirring time, reagent dosage, flotation time, and other parameters were the same as in Example 2.

[0062] Comparative Example 5

[0063] The process flow of this comparative example is the same as that of Example 2. For comparison, the difference between this comparative example and Example 2 is that the inhibitor used is water glass + iminodisuccinic acid, with the mass percentages of water glass and iminodisuccinic acid being 65% and 35%, respectively. The flotation results are shown in Table 2. The specific operating steps are as follows:

[0064] The pulp pH was adjusted to 9. During the fluorite roughing process, the depressant used was organic water glass + iminodisuccinic acid, at a dosage of 750 g / t. In the fluorite finishing process: Finishing I and Finishing II: the dosage of water glass + iminodisuccinic acid was 250 g / t; Finishing III, Finishing IV and Finishing V: the dosage of water glass + iminodisuccinic acid was 80 g / t; Finishing VI and Finishing VII: the dosage of water glass + iminodisuccinic acid was 25 g / t. The other reagent types, stirring time, reagent dosages, flotation time, and flotation time were the same as in Example 2.

[0065] Comparative Example 6

[0066] The process flow of this comparative example is the same as that of the example. For comparison, the difference between this comparative example and example 2 is that the inhibitor used is water glass + carboxymethyl cellulose, and the mass percentages of water glass and carboxymethyl cellulose are 65% and 35%, respectively. The flotation results are shown in Table 2. The specific operation steps are as follows:

[0067] The pulp pH was adjusted to 9. During the fluorite roughing process, the depressant used was water glass + carboxymethyl cellulose at a dosage of 750 g / t. In the fluorite finishing process: for Finishing I and Finishing II, the dosage of water glass + carboxymethyl cellulose was 250 g / t; for Finishing III, Finishing IV, and Finishing V, the dosage was 80 g / t; and for Finishing VI and Finishing VII, the dosage was 25 g / t. The types of reagents added, stirring time, reagent dosage, flotation time, and other parameters were the same as in Example 2.

[0068] Table 2. Results of the full-process closed-loop test for Example 2 and Comparative Examples 4-6

[0069]

[0070] Table 2 shows that, under the same flotation process, flotation collector, flotation pulp concentration, and flotation pH conditions, compared with single inorganic flotation depressants such as water glass and water glass + iminodisuccinic acid, the combined depressant (water glass, iminodisuccinic acid, and carboxymethyl cellulose at mass percentages of 65%, 25%, and 10%) achieves higher CaF2 grades and recoveries, with values ​​of 91.39% and 72.61%, respectively. Although the recovery rate under the water glass + carboxymethyl cellulose condition is slightly higher than that under the combined depressant condition, reaching 73.26%, the grade is only 88.46%. Therefore, the combined depressant described in this invention is a good flotation depressant for calcareous gangue minerals in fluorite flotation.

Claims

1. A combined depressant for the flotation separation of fluorite and calcium-bearing gangue minerals, characterized in that: The combined inhibitor comprises water glass, iminodisuccinic acid, and carboxymethyl cellulose; the combined inhibitor contains 60%–75% water glass by mass, 15%–30% iminodisuccinic acid by mass, 10%–25% carboxymethyl cellulose by mass, and the total mass percentage of water glass, iminodisuccinic acid, and carboxymethyl cellulose is 100%.

2. The application of the combined inhibitor for flotation separation of fluorite and calcareous gangue minerals as described in claim 1 in the flotation separation of fluorite and calcareous gangue minerals.

3. The application according to claim 2, characterized in that: Fluorite concentrate and fluorite tailings are obtained from fluorite ore through a process of one roughing, seven cleaning, and two scavenging.

4. The application according to claim 3, characterized in that: Combination inhibitors were added during the first coarse selection and the seventh fine selection, but not during other processes.

5. The application according to claim 4, characterized in that: In the first coarse selection process, the amount of combined inhibitor added was 450–750 g / t; in the seven fine selection processes, the amount of combined inhibitor added in Fine Selection I and Fine Selection II was 150–250 g / t, the amount of combined inhibitor added in Fine Selection III, Fine Selection IV and Fine Selection V was 50–84 g / t, and the amount of combined inhibitor added in Fine Selection VI and Fine Selection VII was 16–28 g / t.

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