Positive and double reverse flotation process for removing silicon, magnesium, iron and aluminum from phosphorite

Abstract

The invention discloses a positive and double reverse flotation process for removing silicon, magnesium, iron and aluminum from phosphorite, and relates to the technical field of phosphorite flotation. High-grade phosphate concentrate, low-grade phosphate concentrate and tailings are obtained by performing direct flotation desiliconization, reverse flotation magnesium removal in acidic ore pulp and secondary reverse flotation iron and aluminum removal in the acidic ore pulp on phosphorite under a weak alkali condition. The method specifically comprises the following steps: crushing and grinding collophanite to obtain flotation raw ore pulp; adding sodium carbonate serving as a pH regulator, sodium silicate serving as an inhibitor, MON-135 serving as a collecting agent and LSD-Z serving as a synergist into the raw ore pulp to obtain positive flotation tailings and desiliconized phosphate concentrate pulp; a pH regulator sulfuric acid is added into the desiliconized phosphate concentrate pulp, the pH value is regulated to be 4-5, then a reverse flotation collecting agent LAA-T is added, and reverse flotation tailings and magnesium-removed phosphate concentrate pulp are obtained; and after a collecting agent E1310P is added into the magnesium-removed phosphate concentrate pulp to be fully mixed and mixed, high-grade phosphate concentrate and low-grade phosphate concentrate are obtained through secondary reverse flotation, the grade of phosphorus in the high-grade phosphate concentrate is larger than 30%, the recovery rate of P2O5 is larger than 50%, and the MER value is smaller than 0.08.

Description

Technical Field

[0001] The present invention relates to the technical field of phosphate ore flotation, and particularly to a positive double reverse flotation process for removing silicon, magnesium, iron and aluminum from phosphate ore. Background Art

[0002] With the gradual consumption of high-grade phosphate ore resources, low-grade phosphate ore has also been gradually developed and applied in industrial production. Low-grade phosphate ore has a low phosphorus grade and contains gangue minerals such as iron, aluminum, magnesium and silicon. Before being applied in production, it usually needs to be flotated to enrich phosphorus and remove various gangue minerals. Among them, magnesium, iron, aluminum and silicon have a greater impact on downstream production. Such gangue minerals mainly exist in dolomite, quartz, limonite, diaspore and potassium feldspar. The common flotation methods in phosphate ore flotation are positive flotation and reverse flotation. Among them, reverse flotation is often used to remove dolomite minerals, and positive flotation is often used to remove quartz minerals. There is less research on the method of removing iron and aluminum. Iron and aluminum are more present in limonite, diaspore and potassium feldspar. Limonite and diaspore are easy to slime, and are easy to adhere to the foam and float up in positive flotation, while are inhibited in the phosphate concentrate in reverse flotation, resulting in a higher content of Fe2O3 and Al2O3 in the phosphate concentrate. Therefore, it is urgent to develop a flotation process that can further reduce the iron and aluminum content in the phosphate concentrate while removing silicon and magnesium. Summary of the Invention

[0003] The purpose of the present invention is to provide a positive double reverse flotation process for removing silicon, magnesium, iron and aluminum from phosphate ore, so as to solve the problem of unsatisfactory removal effect of iron and aluminum in the existing process.

[0004] To solve the above technical problems, the present invention adopts the following technical solutions: a positive double reverse flotation process for removing silicon, magnesium, iron and aluminum from phosphate ore, characterized in that: by carrying out positive flotation to remove silicon under weak alkaline conditions, reverse flotation to remove magnesium in acidic pulp, and secondary reverse flotation to remove iron and aluminum in acidic pulp on the phosphate ore, high-grade phosphate concentrate, low-grade phosphate concentrate and tailings are obtained.

[0005] A further technical solution is that the specific steps of the flotation process are as follows: S1. The collophanite is crushed and ground to a content of -0.075mm greater than 80% to obtain a flotation raw ore pulp with a concentration of 20% - 25%; S2. Positive flotation to remove silicon: Sodium carbonate as a pH adjuster, water glass as an inhibitor, MON-135 as a collector and LSD-Z as a synergist are added to the raw ore pulp. After pulp conditioning, one roughing, one cleaning and one scavenging are carried out. The collector MON-135 is added during scavenging, and the scavenging middlings are returned to the roughing process to obtain positive flotation tailings and desiliconized phosphate concentrate pulp; S3. Reverse flotation to remove magnesium: Add sulfuric acid, a pH adjuster, to the desilicated phosphate concentrate slurry to adjust the pH value to 4 - 5. Then add the reverse flotation collector LAA-T. After pulp conditioning, conduct one roughing, one cleaning, and three scavenging operations. Add the collector LAA-T during cleaning and add sulfuric acid during scavenging. The middlings from the reverse flotation cleaning and the first reverse flotation scavenging are combined and returned to the reverse flotation roughing process. The middlings from the second reverse flotation scavenging are returned to the first reverse flotation scavenging process, and the middlings from the third reverse flotation scavenging are returned to the second reverse flotation scavenging process to obtain reverse flotation tailings and magnesium-removed phosphate concentrate slurry. S4. Secondary reverse flotation for removing iron and aluminum: Add the collector E1310P to the magnesium-removed phosphate concentrate slurry, fully mix and condition the pulp, and then obtain high-grade phosphate concentrate and low-grade phosphate concentrate through the second reverse flotation.

[0006] A further technical solution is that in the step S1, the P2O5 content in the collophanite is 18 - 22%, the SiO2 content is 18 - 25%, the MgO content is 4 - 5.5%, and the sesquioxide content is 2.5 - 4.5%.

[0007] A further technical solution is that in the step S2, the dosage of sodium carbonate is 2 - 5 kg / t, the dosage of water glass is 4 - 6 kg / t, the dosage of the collector MON-135 is 0.5 - 0.8 kg / t, the dosage of the synergist LSD-Z is 100 - 200 g / t, and the dosage of the collector MON-135 added during scavenging is 0.2 - 0.4 kg / t.

[0008] A further technical solution is that in the step S3, the dosage of sulfuric acid is 20 - 22 kg / t, the dosage of the collector LAA-T is 0.5 - 0.7 kg / t, the dosage of the collector LAA-T added during reverse flotation cleaning is 0.1 - 0.2 kg / t, the dosage of sulfuric acid added during the first reverse flotation scavenging is 5 - 7 kg / t, the dosage of sulfuric acid added during the second reverse flotation scavenging is 5 - 7 kg / t, and the dosage of sulfuric acid added during the third reverse flotation scavenging is 2 - 5 kg / t.

[0009] A further technical solution is that in the step S4, the dosage of the collector E1310P is 50 - 125 g / t.

[0010] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention provides a weak alkaline condition through sodium carbonate, efficiently removes silicon through the synergistic action of water glass, the collector MON-135, and the synergist LSD-Z, quickly removes magnesium through reverse flotation under acidic pulp, and then conducts secondary reverse flotation by adding the collector E1310P to concentrate iron and aluminum in the low-grade phosphate ore, thereby obtaining high-grade phosphate ore with silicon, magnesium, iron, and aluminum removed. The phosphate grade is greater than 30%, the recovery rate of P2O5 is greater than 50%, and the MER value is less than 0.08. Brief Description of the Drawings

[0011] Figure 1 This is the process flow diagram of the present invention. Detailed implementation manners

[0012] In order to make the objectives, technical solutions and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0013] Embodiment 1 This embodiment applies the positive-dual reverse flotation process for desiliconization, magnesia, iron and aluminum removal to collophanite with an average P2O5 content of 21.89%, SiO2 content of 20.87%, MgO content of 4.28%, and sesquioxide (Fe2O3 + Al2O3) content of 2.78%. The process flow is shown in Figure 1 , and the specific process steps are as follows: (1) Pulp preparation process Crush and grind collophanite with an average P2O5 content of 21.89%, SiO2 content of 20.87%, MgO content of 4.28%, and sesquioxide (Fe2O3 + Al2O3) content of 2.78% to a content of more than 80% of -0.075 mm, obtaining flotation raw ore pulp with a concentration of 22.5%; (2) Positive flotation desiliconization process Add pH adjuster sodium carbonate, inhibitor water glass, collector MON-135 and synergist LSD-Z to the pulp. After pulp conditioning, perform one rough selection, one fine selection and one scavenging. Add collector MON-135 during scavenging. The middle ore of scavenging 1 returns to the rough selection process to obtain positive flotation tailings and desiliconized phosphorus concentrate pulp; obtain desiliconized magnesium phosphorus concentrate with a P2O5 content of 24.35%, SiO2 content of 20.12%, MgO content of 4.78%, and sesquioxide (Fe2O3 + Al2O3) content of 2.67%. The P2O5 content of the positive flotation desiliconization tailings is 9.43%.

[0014] (3) Reverse flotation magnesia removal process Add sulfuric acid as a pH adjuster to adjust the pH value of the desiliconized concentrate pulp to 4.5, and then add reverse flotation collector LAA-T. After pulp conditioning, perform one rough selection, one fine selection and three scavengings. Add collector LAA-T during fine selection and sulfuric acid during scavenging. The middle ore 5 of reverse flotation fine selection and the middle ore 2 of reverse flotation scavenging 1 are merged and returned to the reverse flotation rough selection process. The middle ore 3 of reverse flotation scavenging 2 returns to the reverse flotation scavenging 1 process, and the middle ore 4 of reverse flotation scavenging 3 returns to the reverse flotation scavenging 2 process to obtain reverse flotation tailings and desiliconized magnesium phosphorus concentrate pulp; obtain desiliconized magnesium phosphorus concentrate with a P2O5 content of 26.85%, SiO2 content of 19.17%, MgO content of 0.90%, and sesquioxide (Fe2O3 + Al2O3) content of 2.73%. The P2O5 content of the reverse flotation magnesia removal tailings is 6.99%.

[0015] (4)Reverse flotation process for removing iron and aluminum After adding collector E1310P to the magnesium-removed phosphate concentrate pulp and fully mixing and adjusting the pulp, high-grade phosphate concentrate 1 and low-grade phosphate concentrate 2 are obtained through the second reverse flotation. The grade of phosphate concentrate 1 is 31.85%, and the MER value is 0.075, which can be used as high-quality chemical raw materials to produce high-value phosphorus chemical products; the grade of phosphate concentrate 2 is 28.86%, which can be used as raw materials for producing fertilizer products.

[0016] In the above examples, the dosages of sodium carbonate, water glass, MON-135 and LSD-Z in the positive flotation roughing are 4 kg / t, 5 kg / t, 0.7 kg / t and 156 g / t respectively, and the dosage of MON-135 in the positive flotation scavenging is 0.3 kg / t; the dosages of sulfuric acid and LAA-T in the reverse flotation roughing are 21 kg / t and 0.6 kg / t respectively, the dosages of sulfuric acid in the reverse flotation scavenging 1, 2 and 3 are 6 kg / t, 6 kg / t and 3 kg / t respectively, and the dosage of LAA-T in the reverse flotation cleaning is 0.15 kg / t; the dosage of E1310P in the second reverse flotation is 75 g / t.

[0017] Example 2 In this example, the application of the positive-double reverse flotation process for desiliconization, magnesium, iron and aluminum of collophanite with an average P2O5 content of 20.50%, SiO2 content of 22.27%, MgO content of 5.35% and sesquioxide (Fe2O3+Al2O3) content of 2.96% is carried out. The process flow is shown in Figure 1 , and the specific process steps are as follows: (1)Pulp preparation process The collophanite with an average P2O5 content of 20.50%, SiO2 content of 22.27%, MgO content of 5.35% and sesquioxide (Fe2O3+Al2O3) content of 2.96% is crushed and ground to a flotation raw ore pulp with a content of -0.075 mm greater than 80% and a concentration of 23.12%. (2)Positive flotation desiliconization process pH adjuster sodium carbonate, inhibitor water glass, collector MON-135 and synergist LSD-Z are added to the pulp. After adjusting the pulp, one roughing, one cleaning and one scavenging are carried out. The collector MON-135 is added during scavenging. The middlings of scavenging 1 are returned to the roughing process to obtain positive flotation tailings 1 and desiliconized phosphate concentrate pulp; desiliconized magnesium-removed phosphate concentrate with a P2O5 content of 23.67%, SiO2 content of 18.34%, MgO content of 5.18% and sesquioxide (Fe2O3+Al2O3) content of 2.32% is obtained, and the P2O5 content of the positive flotation desiliconization tailings is 10.56%.

[0018] (3)Reverse flotation process for removing magnesium Add sulfuric acid as a pH adjuster to adjust the pH value of the desilicated concentrate pulp to 4.5, then add the reverse flotation collector LAA-T. After pulp conditioning, conduct one roughing, one cleaning, and three scavenging operations. Add the collector LAA-T during cleaning and sulfuric acid during scavenging. The middlings 5 from the reverse flotation cleaning and the middlings 2 from the first scavenging of the reverse flotation are combined and returned to the reverse flotation roughing process. The middlings 3 from the second scavenging of the reverse flotation are returned to the first scavenging process of the reverse flotation, and the middlings 4 from the third scavenging of the reverse flotation are returned to the second scavenging process of the reverse flotation to obtain the reverse flotation tailings and the magnesium-removed phosphate concentrate pulp; obtain magnesium-removed phosphate concentrate with P2O5 content of 25.98%, SiO2 content of 18.12%, MgO content of 0.87%, and sesquioxide (Fe2O3 + Al2O3) content of 2.13%. The P2O5 content of the reverse flotation magnesium-removed tailings is 7.26%.

[0019] (4)Reverse flotation for iron and aluminum removal process After adding the collector E1310P to the magnesium-removed phosphate concentrate pulp and fully mixing and conditioning the pulp, high-grade phosphate concentrate 1 and low-grade phosphate concentrate 2 are obtained through the second reverse flotation. The grade of phosphate concentrate 1 is 31.13% and the MER value is 0.058, which can be used as high-quality chemical raw materials to produce high-value phosphorus chemical products; the grade of phosphate concentrate 2 is 27.34%, which can be used as raw materials for producing fertilizer products.

[0020] In the above examples, the dosages of sodium carbonate, water glass, MON-135, and LSD-Z in the positive flotation roughing are 4.5 kg / t, 5.5 kg / t, 0.75 kg / t, and 200 g / t respectively, and the dosage of MON-135 in the positive flotation scavenging is 0.35 kg / t; the dosages of sulfuric acid and LAA-T in the reverse flotation roughing are 23 kg / t and 0.7 kg / t respectively, the dosages of sulfuric acid in the first, second, and third scavenging of the reverse flotation are 7 kg / t, 7 kg / t, and 4 kg / t respectively, and the dosage of LAA-T in the reverse flotation cleaning is 0.2 kg / t; the dosage of E1310P in the second reverse flotation is 100 g / t.

[0021] Example 3 This example applies the positive-double reverse flotation process for desilication, magnesium removal, iron removal, and aluminum removal to collophanite with an average P2O5 content of 18.72%, SiO2 content of 25.68%, MgO content of 6.53%, and sesquioxide (Fe2O3 + Al2O3) content of 3.56%. The process flow is shown in Figure 1 and the specific process steps are as follows: (1)Pulp preparation process Crush and grind collophanite with an average P2O5 content of 18.72%, SiO2 content of 25.68%, MgO content of 6.53%, and sesquioxide (Fe2O3 + Al2O3) content of 3.56% to a particle size with -0.075 mm content greater than 80% to obtain a flotation raw ore pulp with a concentration of 22.35%. (2)Positive flotation for desilication process Sodium carbonate as a pH regulator, water glass as an inhibitor, MON-135 as a collector and LSD-Z as a synergist are added to the pulp. After pulp conditioning, one rough selection, one cleaning and one scavenging are carried out. The collector MON-135 is added during scavenging. The middlings from the first scavenging are returned to the rough selection process to obtain positive flotation tailings 1 and desiliconized phosphate concentrate pulp; desmagnesium phosphate concentrate with a P2O5 content of 22.83%, a SiO2 content of 22.67%, a MgO content of 5.58% and a sesquioxide (Fe2O3 + Al2O3) content of 3.24% is obtained, and the positive flotation desiliconized tailings have a P2O5 content of 11.26%.

[0022] (3)Reverse flotation desmagnesium process Sulfuric acid is added as a pH regulator to adjust the pH value of the desiliconized concentrate pulp to about 4.5, and then the reverse flotation collector LAA-T is added. After pulp conditioning, one rough selection, one cleaning and three scavengings are carried out. The collector LAA-T is added during cleaning, and sulfuric acid is added during scavenging. The middlings 5 from the reverse flotation cleaning and the middlings 2 from the first reverse flotation scavenging are combined and returned to the reverse flotation rough selection process. The middlings 3 from the second reverse flotation scavenging are returned to the first reverse flotation scavenging process, and the middlings 4 from the third reverse flotation scavenging are returned to the second reverse flotation scavenging process to obtain reverse flotation tailings and desmagnesium phosphate concentrate pulp; desmagnesium phosphate concentrate with a P2O5 content of 26.71%, a SiO2 content of 20.45%, a MgO content of 0.83% and a sesquioxide (Fe2O3 + Al2O3) content of 2.56% is obtained, and the reverse flotation desmagnesium tailings have a P2O5 content of 5.24%.

[0023] (4)Reverse flotation deiron-aluminum process After adding the collector E1310P to the desmagnesium phosphate concentrate pulp and fully mixing and conditioning, high-grade phosphate concentrate 1 and low-grade phosphate concentrate 2 are obtained through the second reverse flotation. The grade of phosphate concentrate 1 is 30.35% and the MER value is 0.071, which can be used as high-quality chemical raw materials to produce high-value phosphorus chemical products; the grade of phosphate concentrate 2 is 27.02%, which can be used as raw materials for producing fertilizer products.

[0024] In the above examples, the dosages of sodium carbonate, water glass, MON-135 and LSD-Z in the positive flotation rough selection are 5 kg / t, 6 kg / t, 0.8 kg / t and 250 g / t respectively, and the dosage of MON-135 in the positive flotation scavenging is 0.4 kg / t; the dosages of sulfuric acid and LAA-T in the reverse flotation rough selection are 24 kg / t and 0.75 kg / t respectively, and the dosages of sulfuric acid in the first, second and third reverse flotation scavengings are 7 kg / t, 7 kg / t and 5 kg / t respectively, and the dosage of LAA-T in the reverse flotation cleaning is 0.25 kg / t; the dosage of E1310P in the second reverse flotation is 150 g / t.

[0025] Although the present invention has been described herein with reference to a number of illustrative embodiments, it should be understood that those skilled in the art can devise many other modifications and embodiments that will fall within the scope of the principles disclosed in this application and the spirit thereof. More specifically, within the scope of the disclosure, the drawings, and the claims of this application, various deformations and improvements can be made to the components or layout of the subject combination layout. In addition to the deformations and improvements to the components or layout, other uses will also be obvious to those skilled in the art.

Claims

1. A positive double reverse flotation process for removing silicon, magnesium, iron, and aluminum from phosphate rock, characterized in that: By subjecting the phosphate rock to positive flotation desilication under weak alkaline conditions, reverse flotation de-magnesium in acidic pulp, and secondary reverse flotation de-iron and de-aluminum in acidic pulp, high-grade phosphate concentrate, low-grade phosphate concentrate, and tailings are obtained.

2. The positive double reverse flotation process for removing silicon, magnesium, iron and aluminum from phosphate rock according to claim 1, characterized in that: The specific steps of the flotation process are as follows: S1. Crush the collophanite and grind it to a content of more than 80% with a particle size of -0.075 mm to obtain a flotation raw ore pulp with a concentration of 20% - 25%. S2. Positive flotation desilication: Add the pH regulator sodium carbonate, inhibitor water glass, collector MON-135, and synergist LSD-Z to the raw ore pulp. After pulp conditioning, conduct one roughing, one cleaning, and one scavenging. Add the collector MON-135 during scavenging, and return the scavenging middlings to the roughing process to obtain positive flotation tailings and desilicated phosphate concentrate pulp. S3. Reverse flotation de-magnesium: Add sulfuric acid as the pH regulator to the desilicated phosphate concentrate pulp to adjust the pH value to 4 - 5, and then add the reverse flotation collector LAA-T. After pulp conditioning, conduct one roughing, one cleaning, and three scavengings. Add the collector LAA-T during cleaning, and add sulfuric acid during scavenging. Combine the reverse flotation cleaning middlings and the first reverse flotation scavenging middlings and return them to the reverse flotation roughing process. Return the second reverse flotation scavenging middlings to the first reverse flotation scavenging process, and return the third reverse flotation scavenging middlings to the second reverse flotation scavenging process to obtain reverse flotation tailings and de-magnesium phosphate concentrate pulp. S4. Secondary reverse flotation de-iron and de-aluminum: Add the collector E1310P to the de-magnesium phosphate concentrate pulp, fully mix and condition the pulp, and then obtain high-grade phosphate concentrate and low-grade phosphate concentrate through the second reverse flotation.

3. The positive double reverse flotation process for removing silicon, magnesium, iron and aluminum from phosphate rock according to claim 2, characterized in that: In the collophanite in step S1, the P2O5 content is 18 - 22%, the SiO2 content is 18 - 25%, the MgO content is 4 - 5.5%, and the sesquioxide content is 2.5 - 4.5%.

4. The positive double reverse flotation process for removing silicon, magnesium, iron and aluminum from phosphate rock according to claim 2, characterized in that: In step S2, the dosage of sodium carbonate is 2 - 5 kg / t, the dosage of water glass is 4 - 6 kg / t, the dosage of collector MON-135 is 0.5 - 0.8 kg / t, the dosage of synergist LSD-Z is 100 - 250 g / t, and the dosage of collector MON-135 added during scavenging is 0.2 - 0.4 kg / t.

5. The positive double reverse flotation process for desilication, magnesium, iron and aluminum removal from phosphate rock according to claim 2, characterized in that: In step S3, the dosage of sulfuric acid is 20 - 22 kg / t, the dosage of collector LAA-T is 0.5 - 0.75 kg / t, the dosage of collector LAA-T added during reverse flotation cleaning is 0.1 - 0.3 kg / t, the dosage of sulfuric acid added during the first reverse flotation scavenging is 5 - 7 kg / t, the dosage of sulfuric acid added during the second reverse flotation scavenging is 5 - 7 kg / t, and the dosage of sulfuric acid added during the third reverse flotation scavenging is 2 - 5 kg / t.

6. The positive double reverse flotation process for removing silicon, magnesium, iron and aluminum from phosphate rock according to claim 2, characterized in that: In step S4, the dosage of collector E1310P is 50 - 150 g / t.

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