Combined inhibitor for reverse flotation magnesium removal of middle-low-grade phosphorite and application of combined inhibitor

Abstract

The invention relates to a combined inhibitor for reverse flotation magnesium removal of medium-low grade phosphorite and application thereof. The combined inhibitor comprises sodium sulfate, 1, 2, 4-butanetricarboxylic acid and sulfuric acid. The application method comprises the following steps: grinding raw ore, adding water and mixing to obtain ore pulp; the pH of the ore pulp is adjusted, then the combined inhibitor is sequentially added and mixed, then a collecting agent is added and mixed, flotation is conducted, and phosphate concentrate and phosphate tailings are obtained; the flotation process comprises one-time rough flotation, at least one-time fine flotation and at least one-time scavenging; the combined inhibitor provided by the invention is good in calcium and magnesium interference resistance and high in selectivity, the dosage of sulfuric acid is remarkably reduced, the pH value of ore pulp is increased, magnesian gangue in phosphorite is effectively removed through the synergistic effect of all the components, the grade of phosphate concentrate is increased, meanwhile, the recovery rate is high, and the combined inhibitor has good industrial application prospects.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of phosphate ore reverse flotation, and more particularly to a combined depressant for reverse flotation of medium and low grade phosphate ore and application thereof. BACKGROUND

[0002] Phosphorus is a non-metallic element, which is widely used in the manufacture of phosphate fertilizer, phosphoric acid and other purposes, and is often applied in the fields of agriculture, chemical industry, construction and the like. Phosphate ore is the main source of phosphorus, and is an important chemical mineral raw material, which belongs to strategic non-metallic mineral resources. The rational and efficient development and utilization of phosphate ore is of great importance because phosphate ore is non-renewable. The content of magnesium in medium and low grade phosphate ore is usually high, and the magnesium mainly exists in the form of minerals such as dolomite. These impurities seriously affect the quality of phosphate concentrate and the subsequent further processing and utilization of phosphate ore. For example, in the production of phosphoric acid, dolomite will consume a large amount of acid, thereby producing acid wastewater and reducing the resource utilization rate of phosphate ore. Therefore, how to efficiently remove magnesium in medium and low grade phosphate ore is related to the efficient enrichment and utilization of phosphate ore resources.

[0003] At present, reverse flotation is one of the effective methods for improving the P2O5 grade and reducing the MgO content in medium and low grade phosphate ore. The reverse flotation magnesium removal process of phosphate ore refers to the efficient flotation removal of magnesium-containing minerals in phosphate ore, so as to realize the efficient flotation separation of phosphate ore and magnesium-containing minerals. In the traditional reverse flotation process, the commonly used depressant is mainly inorganic acid, such as phosphoric acid and sulfuric acid. This kind of depressant is mainly used to inhibit phosphate ore. However, the dosage of single inorganic acid is large, the slurry solution has high acidity, which can easily corrode the beneficiation equipment, and the subsequent treatment of beneficiation wastewater is also difficult.

[0004] Therefore, it is of important practical application significance to develop an efficient combined depressant for reverse flotation magnesium removal of medium and low grade phosphate ore and an application method thereof, so as to improve the utilization efficiency of phosphate ore resources, reduce the dosage of traditional reverse flotation depressant, and reduce the beneficiation cost. SUMMARY

[0005] Based on the above technical problems existing in the prior art, the present application provides a combined depressant for reverse flotation magnesium removal of medium and low grade phosphate ore. The combined depressant is applied to the reverse flotation magnesium removal of phosphate ore, which can effectively separate magnesium gangue in phosphate ore, improve the grade of phosphate concentrate, and has high recovery rate.

[0006] In order to achieve the above purpose, the technical scheme of the present application is as follows:

[0007] A combined depressant for reverse flotation magnesium removal of medium and low grade phosphate ore, comprising sodium sulfate, 1,2,4-butanetricarboxylic acid and sulfuric acid.

[0008] In some embodiments, the mass ratio of sodium sulfate, 1,2,4-butanetricarboxylic acid and sulfuric acid is (5-25):(0.5-3):(5-15).

[0009] The application also provides the application of the combined depressant of any of the above embodiments in the reverse flotation of phosphate ore.

[0010] In some embodiments, the application method of the combined depressant in the reverse flotation of phosphate ore includes the following steps:

[0011] S1, grinding the raw ore, adding water to adjust the slurry, and obtaining the ore slurry;

[0012] S2, adjusting the pH of the ore slurry, then adding the combined depressant, mixing, then adding the collector, mixing, and performing flotation to obtain the phosphate concentrate and the phosphate tailings;

[0013] The flotation process includes one roughing, at least one cleaning, and at least one scavenging.

[0014] In some embodiments, the flotation process includes:

[0015] The roughing process: adding the collector to the mixed slurry, performing flotation, and obtaining the roughing concentrate and the roughing tailings;

[0016] The cleaning process: adding the combined depressant to the ore slurry after adjusting the pH, mixing, then adding the collector, mixing, and performing flotation to obtain the cleaning concentrate and the cleaning tailings; the cleaning tailings are returned to the raw ore slurry for roughing; and the cleaning concentrate is the final phosphate concentrate product;

[0017] The scavenging process: adding the collector to the roughing tailings, performing flotation, and obtaining the scavenging concentrate and the scavenging tailings; the scavenging concentrate is returned to the raw ore slurry for roughing; and the scavenging tailings are the phosphate tailings product.

[0018] In some embodiments, in step S1, the raw ore is ground to a fineness of more than 80% of -0.074 mm, water is added to adjust the slurry, and the ore slurry with a concentration of 15-30% is obtained.

[0019] In some embodiments, in step S2, the pH of the ore slurry is adjusted to 5-7 by using the adjusting agent hydrochloric acid.

[0020] In some embodiments, in the roughing process in step S2, the combined inhibitor is added in an amount of 2000-3000 g / t, the mixing time is 4-6 min, the collector is sodium oleate, which is added in an amount of 600-1000 g / t, the mixing time of the collector is 3-5 min, and the floating time is 4-6 min; in the cleaning process, the combined inhibitor is added in an amount of 500-1000 g / t, the mixing time is 2-5 min, the collector is added in an amount of 200-500 g / t, the mixing time is 1-3 min, and the floating time is 2-4 min; in the scavenging process, the collector is added in an amount of 0-200 g / t, the mixing time is 0-2 min, and the floating time is 3-5 min.

[0021] In some embodiments, in the crude ore, the P2O5 grade is 15-21%, and the MgO content is 1-5%.

[0022] The application also provides the phosphate concentrate obtained by the application method, wherein the P2O5 grade of the phosphate concentrate is more than 26%, and the MgO content is less than 1%.

[0023] Compared with the prior art, the application has the following beneficial effects:

[0024] (1) The application first proposes to use the combination of the inorganic adjusting agent sodium sulfate, the organic small-molecule inhibitor 1,2,4-butanetricarboxylic acid, and the inorganic inhibitor sulfuric acid as the combined inhibitor for the reverse flotation and magnesium removal of the medium and low grade phosphate ore, wherein the polar group carboxyl in the 1,2,4-butanetricarboxylic acid can be selectively adsorbed on the calcium ion active site of the target minerals such as apatite to play a selective inhibition role, thereby realizing the efficient removal of magnesium minerals in the medium and low grade phosphate ore; the mixed system of the organic inhibitor and the inorganic inhibitor formed by the 1,2,4-butanetricarboxylic acid and the sulfuric acid can improve the inhibition effect of the sulfuric acid, reduce the dosage of the single sulfuric acid, and reduce the adverse effects of the single sulfuric acid system on the flotation; the addition of sodium sulfate can provide a large amount of sulfate radicals in the ore pulp, which can react with calcium and magnesium ions in the solution to play a buffering role and effectively reduce the influence of interfering ions in the ore pulp, and can improve the quality of the flotation froth and enhance the flotation separation efficiency of the phosphate ore and the magnesium minerals.

[0025] (2) The application of the combined inhibitor in the application successfully realizes the efficient flotation separation of the phosphate ore and the magnesium gangue minerals, obtains the phosphate concentrate with a MgO content of less than 1% and a P2O5 grade of more than 26%, and has a P2O5 recovery rate of more than 91.95%, thereby improving the flotation efficiency of the reverse flotation and magnesium removal of the phosphate ore.

[0026] (3) The combined inhibitor in the present application has simple composition, low cost and is green and environmentally friendly, which not only improves the flotation separation efficiency, reduces the amount of sulfuric acid, reduces the adverse effects of single sulfuric acid inhibitor, and improves the pH value of the ore pulp, slows down the corrosion of the flotation equipment and prolongs the service life thereof.

[0027] (4) The combined inhibitor in the present application reduces the acidic wastewater generated by the single sulfuric acid inhibitor, reduces the difficulty of tailings wastewater treatment, and reduces the generation of solid waste phosphogypsum. BRIEF DESCRIPTION OF DRAWINGS

[0028] Figure 1 Process flow chart of examples and comparative examples. DETAILED DESCRIPTION

[0029] In the following description, a lot of specific details are set forth in order to provide a thorough understanding of the present application. However, the present application can be practiced in a variety of ways beyond the specific embodiments described and claimed herein, and it is understood that it can be employed in other different embodiments which are within the scope of the present application and that modifications can be made by those skilled in the art, without departing from the spirit of the present application. Therefore, the present application is not intended to be limited to the specific embodiments disclosed herein, but is to be accorded the full scope that can be apparent to one skilled in the art in view of this disclosure.

[0030] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description herein is for describing particular embodiments only and is not intended to be limiting of the present application.

[0031] Example 1

[0032] This embodiment takes a certain low-grade mixed collophanite in Guizhou as the research object, the P2O5 grade in the raw ore is 20.59%, the MgO content is 4.06%, and the gangue minerals are mainly dolomite, calcite, quartz and feldspar, etc.

[0033] The mass ratio of sodium sulfate, 1,2,4-butanetricarboxylic acid and sulfuric acid in the combined inhibitor of this embodiment is 9:1:10, and the collector is selected as 15g / L of sodium oleate aqueous solution.

[0034] The process flow of the phosphorite reverse flotation magnesium removal of this embodiment is shown in Figure 1 The specific steps are as follows:

[0035] (1) The ore sample is ground, the grinding fineness is 85% of -0.074mm, water is added to adjust the pulp concentration to 30%, and hydrochloric acid is added as a pH adjuster to adjust the pH value of the ore pulp to 6;

[0036] (2) Roughing of phosphate ore: 3000 g / t of the combined depressant is added to the slurry of step (1), 1000 g / t of sodium oleate is added after 5 minutes of reaction, and the flotation is carried out after 4 minutes of reaction of sodium oleate, and the flotation time is 5 minutes, the floated product is magnesium-containing gangue tailings, and the phosphate ore rough concentrate is left in the flotation tank;

[0037] (3) Cleaning of phosphate ore: the phosphate ore rough concentrate in step (2) is subjected to cleaning of phosphate ore, 800 g / t of the combined depressant is added, 350 g / t of sodium oleate is added after 3 minutes of reaction, and the flotation is carried out after 3 minutes of stirring, and the floated product is cleaning tailings, and the phosphate ore concentrate is left in the flotation tank; the cleaning tailings are returned to step (1) for roughing;

[0038] (4) Scavenging of phosphate ore: the magnesium-containing gangue tailings in step (2) are subjected to scavenging of phosphate ore, 100 g / t of sodium oleate is added, and the flotation is carried out after 2 minutes of stirring and 4 minutes of flotation, and the floated product is the final phosphate ore tailings, and the scavenging concentrate is left in the flotation tank; the scavenging concentrate is returned to step (1) for roughing.

[0039] The flotation results of the example are shown in Table 1.

[0040] Comparative Example 1

[0041] The ore sample and process flow of the comparative example are the same as those of Example 1, and the difference between the comparative example and Example 1 is that the depressant is single sulfuric acid, and the details are as follows:

[0042] The depressant in step (2) is single sulfuric acid, and the dosage is 3000 g / t;

[0043] The dosage of the depressant sulfuric acid in step (3) is 800 g / t;

[0044] The types, dosages and flotation times of the remaining reagents are the same as those of Example 1.

[0045] The flotation results of the comparative example are shown in Table 1.

[0046] Comparative Example 2

[0047] The ore sample and process flow of the comparative example are the same as those of Example 1, and the difference between the comparative example and Example 1 is that the depressant is single and higher concentration sulfuric acid, and the details are as follows:

[0048] The depressant in step (2) is single sulfuric acid, and the dosage is 8000 g / t;

[0049] The dosage of the depressant sulfuric acid in step (3) is 3000 g / t;

[0050] The types, dosages and flotation times of the remaining reagents are the same as those of Example 1.

[0051] The flotation results of the present comparative example are shown in Table 1.

[0052] Comparative Example 3

[0053] The ore sample and process flow of the present comparative example are the same as those of Example 1, and the difference between the present comparative example and Example 1 is that the depressant is a single 1,2,4-butanetricarboxylic acid, specifically as follows:

[0054] The depressant in step (2) is a single 1,2,4-butanetricarboxylic acid, and the dosage is 800 g / t;

[0055] The dosage of the depressant 1,2,4-butanetricarboxylic acid in step (3) is 100 g / t;

[0056] The types of other reagents, the dosages of the reagents, and the flotation time are the same as those of Example 1;

[0057] The flotation results of the present comparative example are shown in Table 1.

[0058] Table 1: Results of the whole-circuit test of Example 1 and Comparative Examples 1-3

[0059]

[0060]

[0061] As shown in Table 1, under the same flotation process and flotation collector conditions, compared with a single inorganic depressant sulfuric acid and a single organic small molecule depressant 1,2,4-butanetricarboxylic acid, the combined depressant (sodium sulfate, 1,2,4-butanetricarboxylic acid, and sulfuric acid in a mass ratio of 45%, 5%, and 50%) obtains a higher P2O5 grade of the phosphate concentrate, which is 26.49%, a recovery rate of 94.23%, a lower MgO content in the concentrate, which is only 0.51%, and a removal rate of 90.80%. It is shown that the combined depressant of the present application has excellent effects in the reverse flotation of the phosphate ore for magnesium removal.

[0062] Example 2

[0063] In the present example, a certain medium-low grade mixed type collophanite in Yunnan is taken as the research object, the P2O5 grade of the raw ore is 18.24%, the MgO content is 3.85%, and the gangue minerals mainly include dolomite, chalcedony, quartz, and muscovite, etc.

[0064] In the combined depressant of the present example, the mass ratio of sodium sulfate, 1,2,4-butanetricarboxylic acid, and sulfuric acid is 15:2:13, and the collector is selected as a 12 g / L sodium oleate aqueous solution.

[0065] The process flow of the reverse flotation of the phosphate ore for magnesium removal in the present example is as follows: Figure 1The specific steps are as follows:

[0066] (1) The ore sample is ground, the grinding fineness is 80% of -0.074 mm, water is added to reduce the pulp concentration to 25%, hydrochloric acid is used as the pH regulator, and the pH value of the pulp is adjusted to 6.5;

[0067] (2) Phosphate ore roughing: 2500g / t of the combined depressant is added to the pulp in step (1), 800g / t of sodium oleate is added after 5 minutes of reaction, and flotation is carried out after 4 minutes of sodium oleate reaction, the flotation time is 5 minutes, the product floated out is a magnesium-containing gangue tailing, and the phosphate ore rough concentrate remains in the flotation tank;

[0068] (3) Phosphate ore cleaning: the phosphate ore rough concentrate in step (2) is subjected to phosphate ore cleaning, 500g / t of the combined depressant is added, 250g / t of sodium oleate is added after 3 minutes of reaction, and the product floated out is a cleaning tailing, and the phosphate ore concentrate remains in the flotation tank; the cleaning tailing returns to step (1) for roughing;

[0069] (4) Phosphate ore scavenging: the magnesium-containing gangue tailing in step (2) is subjected to phosphate ore scavenging, 120g / t of sodium oleate is added, stirring for 2 minutes, and flotation for 4 minutes, the product floated out is the final phosphate ore tailing, and the scavenging concentrate remains in the flotation tank; the scavenging concentrate returns to step (1) for roughing.

[0070] The flotation results of this example are shown in Table 2.

[0071] Comparative Example 4

[0072] The ore sample and process flow of this comparative example are the same as those of Example 2, and the difference between this comparative example and Example 2 is that the combined depressant of sulfuric acid and sodium sulfate is used, and the mass ratio of the two is 1:1, as follows:

[0073] The amount of the combined depressant in step (2) is 2500g / t;

[0074] The amount of the combined depressant in step (3) is 500g / t;

[0075] The types, amounts and flotation times of the remaining reagents are the same as those of Example 2.

[0076] The flotation results of this comparative example are shown in Table 2.

[0077] Comparative Example 5

[0078] The ore sample and process flow of the present comparative example are the same as those of Example 2, and the difference between the present comparative example and Example 2 is that the inhibitor is a combination of sulfuric acid and 1,2,4-butanetricarboxylic acid, and the mass ratio of sulfuric acid to 1,2,4-butanetricarboxylic acid is 14:1, and the specific steps are as follows:

[0079] The dosage of the combination inhibitor in step (2) is 2500 g / t;

[0080] The dosage of the combination inhibitor sulfuric acid in step (3) is 500 g / t;

[0081] The types of reagents, the dosages of reagents, and the flotation time are the same as those of Example 2.

[0082] The flotation results of the present comparative example are shown in Table 2.

[0083] Comparative Example 6

[0084] The ore sample and process flow of the present comparative example are the same as those of Example 2, and the difference between the present comparative example and Example 2 is that the inhibitor is a combination of 1,2,4-butanetricarboxylic acid and sodium sulfate, and the mass ratio of 1,2,4-butanetricarboxylic acid to sodium sulfate is 4:1, and the specific steps are as follows:

[0085] The dosage of the combination inhibitor in step (2) is 2500 g / t;

[0086] The dosage of the combination inhibitor in step (3) is 500 g / t;

[0087] The types of reagents, the dosages of reagents, and the flotation time are the same as those of Example 1.

[0088] The flotation results of the present comparative example are shown in Table 2.

[0089] Table 2: Results of the whole-process closed-circuit test of Example 2 and Comparative Examples 4-6

[0090]

[0091] As shown in Table 2, under the same conditions at pH = 6.5, the inhibitor effect of the combination of sodium sulfate, 1,2,4-butanetricarboxylic acid and sulfuric acid is better than that of any two combinations of sulfuric acid and sodium sulfate, sulfuric acid and 1,2,4-butanetricarboxylic acid, and 1,2,4-butanetricarboxylic acid and sodium sulfate. At this time, the grade of P2O5 in the concentrate is 26.56%, the recovery rate reaches 91.96%, the content of MgO in the concentrate is 0.68, and the removal rate reaches 88.85%. It is shown that the combination inhibitor has excellent effect in the reverse flotation of phosphorite for removing magnesium.

[0092] Any combination of the technical features in the above-described embodiments can be made, and for the sake of brevity, not all possible combinations are described, however, as long as there is no conflict, any combination of the technical features should be considered within the scope of the present disclosure.

[0093] The above-described embodiments only express several embodiments of the present application, and the description is more specific and detailed, but it should not be understood as a limitation on the scope of the application. It should be noted that for ordinary skilled in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of the present application. Therefore, the scope of protection of the present application should be subject to the content of the claims.

Claims

1. A combined depressant for reverse flotation of medium and low-grade phosphate rock for magnesium removal, characterized in that: These include sodium sulfate, 1,2,4-butanetricarboxylic acid, and sulfuric acid.

2. The combined inhibitor for reverse flotation and magnesium removal of medium and low-grade phosphate rock according to claim 1, characterized in that: The mass ratio of the sodium sulfate, 1,2,4-butanetricarboxylic acid and sulfuric acid is (5-25): (0.5-3): (5-15).

3. Use of the combined depressant according to claim 1 or 2 in reverse flotation magnesium removal of medium and low grade phosphate rock.

4. The use according to claim 3, characterized in that The following steps are involved: S1. Grind the raw ore, add water to prepare the slurry, and obtain slurry; S2, adjusting the pH of the slurry, then adding the combined depressant, mixing, and then adding a collector, mixing, and flotation to obtain phosphate concentrate and phosphate tailings; The flotation process includes one roughing process, at least one cleaning process and at least one scavenging process.

5. The use according to claim 4, characterized in that The flotation process includes: Roughing process: Add combined depressants to the pH-adjusted pulp, mix, then add collectors and perform flotation to obtain roughing concentrate and roughing tailings; Concentration process: adding the combined depressant and collector to the rougher concentrate in sequence, performing flotation to obtain a concentrated concentrate and concentrated tailings; the concentrated tailings are returned to the original ore slurry for roughing; the concentrated concentrate is the final phosphate concentrate product; Scavenging process: adding a collector to the roughing tailings to carry out flotation to obtain scavenging concentrate and scavenging tailings; the scavenging concentrate is returned to the original ore slurry for roughing; the scavenging tailings are phosphate tailings products.

6. The use according to claim 5, characterized in that In step S1, the raw ore is ground to a fineness of -0.074 mm accounting for more than 80%, and water is added to adjust the slurry to obtain a slurry with a concentration of 15-30%; and / or, in step S2, the pH of the slurry is adjusted to 5-7 with hydrochloric acid as an adjusting agent.

7. The use according to claim 5, characterized in that In step S2, during the roughing process, the amount of the combined depressant added is 2000-3000 g / t, the mixing time is 4-6 min, the collector is sodium oleate, the amount added is 600-1000 g / t, the collector mixing time is 3-5 min, and the flotation time is 4-6 min; during the cleaning process, the amount of the combined depressant added is 500-1000 g / t, the mixing time is 2-5 min, the amount of the collector added is 200-500 g / t, the mixing time is 1-3 min, and the flotation time is 2-4 min; during the scavenging process, the amount of the collector added is 0-200 g / t, the mixing time is 0-2 min, and the flotation time is 3-5 min.

8. The use according to any one of claims 4 to 7, characterized in that: In the raw ore, the P2O5 grade is 15-21%, and the MgO content is 1-5%.

9. The phosphate concentrate obtained by the application method according to any one of claims 4 to 8, wherein the P2O5 grade of the phosphate concentrate is above 26% and the MgO content is below 1%.

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