A separation method for high-aluminum, high-silicon and high-phosphorus phosphate rock

Abstract

The present invention relates to a separation method for high-aluminum, high-silicon phosphate ore, belonging to the technical field of phosphate ore beneficiation. It mainly includes three-stage separation operation processes of gravity separation, optoelectronic separation and flotation: the original ore is crushed and then screened by a screening machine, and the oversize product enters the heavy medium beneficiation process to obtain gravity separation concentrate and gravity separation tailings; the gravity separation concentrate undergoes optoelectronic separation to obtain optoelectronic separation concentrate and optoelectronic separation tailings; the optoelectronic separation concentrate and the undersize product of the screening machine enter the grinding process together, and then through the double reverse flotation process to obtain flotation concentrate I and flotation tailings I; after grinding, the optoelectronic separation tailings enter the double reverse flotation process to obtain flotation concentrate II and flotation tailings II respectively. The method of the present invention adopts a combined process of gravity separation, optoelectronic separation and flotation to classify and process phosphate ore, which can not only obtain high-quality concentrate, save costs, but also improve the recovery rate.

Description

Technical Field

[0001] The present invention relates to a beneficiation method, particularly a separation method for high-aluminum, high-silicon phosphate ore. Background Art

[0002] Existing traditional beneficiation technologies have high energy consumption and low quality of phosphate concentrate. Especially for some low-grade colloidal phosphate ores with high sesquioxides, it is difficult to obtain high-quality phosphate concentrate using traditional technologies. In traditional wet-process production of phosphoric acid, impurities contained in phosphate concentrate are all unfavorable for wet-process production of phosphoric acid. When the dissolved iron phosphate or aluminum phosphate in the phosphoric acid solution reaches saturation, very fine precipitates are produced, increasing the loss of P2O5 and the consumption of sulfuric acid. At the same time, the presence of iron phosphate and aluminum phosphate affects the crystallization of calcium sulfate, and the iron phosphate and aluminum phosphate dissolved in phosphoric acid will increase the viscosity of phosphoric acid during concentration, and a large amount of fine iron phosphate and aluminum phosphate will precipitate, affecting the normal operation of the concentrated finished acid. With the continuous depletion of phosphate ore quality, the Fe, Al, and Mg impurities in wet-process phosphoric acid gradually increase, resulting in an increase in the impurity coefficient MER value of wet-process phosphoric acid, which has a greater impact on the subsequent product processing and production.

[0003] Currently, the technically feasible methods for phosphate ore beneficiation mainly include: flotation method, scrubbing and desliming method, heavy medium beneficiation, optoelectronic beneficiation, etc. In view of the continuous depletion trend of phosphate ore resources, developing a beneficiation technology with better economy has become a common topic faced by the entire industry. For dense phosphate ores, due to the small density difference of the ores, simply using physical beneficiation (heavy separation or optoelectronic separation) processes cannot obtain qualified concentrates; simply using the flotation process has disadvantages such as high reagent consumption cost, unsatisfactory beneficiation effect, and inability to obtain high-quality phosphate concentrate. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a separation method for high-aluminum, high-silicon phosphate ore in view of the deficiencies of the prior art. This method adopts a combined process of heavy separation, optoelectronic separation, and flotation, and classifies and processes phosphate ore, which can not only obtain high-quality concentrates but also improve the recovery rate.

[0005] The technical problem to be solved by the present invention is achieved through the following technical solutions. The present invention is a separation method for high-aluminum, high-silicon phosphate ore, and its characteristics are: this method mainly includes three-stage separation operation processes of heavy separation, optoelectronic separation, and flotation:

[0006] (1) The original ore enters the crushing system. After the ore is crushed, it is screened by a screening machine, and the oversize product enters the heavy medium beneficiation process; after heavy medium separation, heavy separation concentrate and heavy separation tailings are obtained respectively;

[0007] (2) The heavy separation concentrate enters the optoelectronic beneficiation process, and optoelectronic separation concentrate and optoelectronic separation tailings are obtained respectively;

[0008] (3) The electro-optical separated concentrate and the undersize product of the screening machine enter the grinding process together. After grinding to an ore particle size of -200 mesh at 54 - 57% (most preferably 55%), they enter the double reverse flotation process to obtain flotation concentrate I and flotation tailing I respectively;

[0009] (4) The electro-optical separated tailing is ground. After grinding to an ore particle size of -200 mesh at 70 - 75% (most preferably 70%), it also enters the double reverse flotation process to obtain flotation concentrate II and flotation tailing II respectively; Flotation tailing I and flotation tailing II are combined into the final tailing.

[0010] For the separation method of high-aluminum high-silicon phosphate ore described in the present invention, a further preferred technical solution is: in step (1): the raw ore enters the crushing system and is crushed to a product particle size of -20 mm, and then is screened by a screening machine with a screen hole of 3 mm to obtain an oversize product of 3 mm - 20 mm and an undersize product of -3 mm.

[0011] For the separation method of high-aluminum high-silicon phosphate ore described in the present invention, a further preferred technical solution is: in step (1): the gravity separation tailing obtained by heavy medium separation is used as building materials.

[0012] For the separation method of high-aluminum high-silicon phosphate ore described in the present invention, a further preferred technical solution is: in step (3) or (4), preferably, the dosage of flotation reagents in the double reverse flotation process is as follows: phosphoric acid containing 49.43% P2O5 is 6.5 - 6.8 kg / t of raw ore, the silicon collector ether polyamine is 0.35 - 0.4 kg / t of raw ore, the regulator phosphate is 2.4 - 2.6 kg / t of raw ore, and PA-69 fatty acid is 0.7 - 0.9 kg / t of raw ore. The most preferred dosage of flotation reagents in the double reverse flotation process is: phosphoric acid containing 49.43% P2O5 is 6.5 kg / t of raw ore, the silicon collector (ether polyamine) is 0.35 kg / t of raw ore, the regulator phosphate is 2.4 kg / t of raw ore, and PA-69 fatty acid is 0.7 kg / t of raw ore.

[0013] For the separation method of high-aluminum high-silicon phosphate ore described in the present invention, the gravity separation can be carried out by the following method: using the specific gravity difference between phosphate and gangue minerals, according to Archimedes' law, particles smaller than the density of the heavy medium will float in the medium, and particles larger than the density of the heavy medium will sink in the medium. The electro-optical separation can be carried out by the following method: after the ore is crushed, it reaches the particle size required by the electro-optical separator, so that the phosphate and gangue minerals are effectively dissociated, and the elemental atomic density in the raw ore is measured by X-ray, and the phosphate minerals and high-silicon minerals are distinguished according to the density difference. The flotation can be carried out by the following method: in an alkaline or acidic pulp, using the separability difference between phosphorus-containing minerals and silicate gangue minerals or carbonate gangue minerals, by adding flotation reagents, concentrate and tailing are obtained respectively.

[0014] In the method of the present invention, the composition of the high-aluminum, high-silicon phosphate ore raw ore is preferably P2O5 18 - 24%, MgO ≤2%, R2O3 (Fe2O3 + Al2O3) 4 - 8%, and SiO2 4 - 8%. The qualities of the flotation concentrate I and flotation concentrate II obtained by the method of the present invention are P2O5 35 - 37% and P2O5 30 - 31.5% respectively.

[0015] Compared with the prior art, the present invention has the following beneficial effects:

[0016] (1) In the present invention, high-grade and low-grade ores are respectively subjected to flotation, and the concentrate grade is high. The high-quality concentrate grade can reach 36.5% (the direct flotation grade is 30.5%), which improves the added value of the product;

[0017] (2) The comprehensive recovery rate is high. Compared with the direct flotation process, the recovery rate is increased from 80.28% to 82.45%;

[0018] (3) The heavy medium separation process discards the waste rock with low P2O5 content in advance, reducing the processing volume of subsequent grinding and flotation operations (reducing the process volume by 15% and the production cost by 3.2 yuan / t of raw ore), saving equipment investment and operating costs; compared with the single flotation process, the power consumption is reduced by 5° / t of raw ore;

[0019] (4) The heavy medium separation process discards the waste rock with low P2O5 content in advance, and this waste rock can be used as building materials, which not only reduces the subsequent tailings treatment cost but also improves the utilization value of the tailings;

[0020] (5) High-grade and low-grade ores are respectively subjected to flotation, reducing the consumption of reagents. Among them, phosphoric acid (P2O5 49.43%) is reduced by about 1.2 kg / t of raw ore, the silicon collector (ether polyamine) is reduced by about 0.05 kg / t of raw ore, the regulator (phosphate) is reduced by about 0.4 kg / t of raw ore, and PA - 69 (fatty acid) is reduced by about 0.1 kg / t of raw ore. Specific Embodiments

[0021] The following further describes the specific technical solutions of the present invention to facilitate those skilled in the art to further understand the present invention without restricting its rights.

[0022] Example 1, an experiment on a combined beneficiation method of heavy separation + optoelectronic separation + flotation for high-aluminum, high-silicon phosphate ore: The beneficiation process of high-aluminum, high-silicon phosphate ore in a beneficiation plant in Hubei mainly includes three stages (heavy separation + optoelectronic separation + flotation) of separation operation processes:

[0023] The first stage of beneficiation process - heavy medium beneficiation: The raw ore with 24% P2O5 enters the crushing system. After crushing, the product particle size is -20 mm. Then it is screened by a screening machine (screen hole 3 mm). The oversize product of 3 mm - 20 mm enters the heavy medium beneficiation process. After heavy medium separation, concentrate with 27.21% P2O5 and tailings with 5% P2O5 are obtained respectively. The tailings after heavy medium beneficiation can be used as building materials.

[0024] The second stage of beneficiation process - optoelectronic beneficiation: The concentrate with 27.21% P2O5 after heavy medium beneficiation enters the optoelectronic beneficiation process, and concentrate with 29.75% P2O5 and tailings with 24.2% P2O5 are obtained respectively.

[0025] The third stage of beneficiation process - double reverse flotation beneficiation:

[0026] The concentrate with 29.75% P2O5 from optoelectronic beneficiation and the -3 mm product (28.00% P2O5) under the screen of the screening machine enter the grinding process together. After grinding to 55% of the ore particle size reaching -200 mesh, they enter the double reverse flotation process, and high-quality concentrate with 36.5% P2O5 and tailings with 12.94% P2O5 are obtained respectively. The tailings from optoelectronic beneficiation are ground to 70% of the ore particle size reaching -200 mesh and then enter the double reverse flotation process, and concentrate with 30.5% P2O5 and tailings with 12.24% P2O5 are obtained respectively. The tailings from the two-stage double reverse flotation are combined into the final tailings with 12.66% P2O5.

[0027] Consumption of flotation reagents:

[0028] Phosphoric acid (P2O5 49.43%): 6.5 kg / t of raw ore,

[0029] Silicon collector (ether polyamine): 0.35 kg / t of raw ore,

[0030] Regulator (phosphate): 2.4 kg / t of raw ore,

[0031] PA - 69 (fatty acid): 0.7 kg / t of raw ore.

[0032] Power consumption: 35 kw.h / t of raw ore.

[0033] Example 2, Experiment 2 on the separation method for high - aluminum and high - silicon phosphate ore:

[0034] The beneficiation process of high - aluminum and high - silicon phosphate ore in a certain beneficiation plant mainly includes three stages (heavy separation + optoelectronic separation + flotation) of separation operation process:

[0035] The first stage of beneficiation process - heavy medium beneficiation: The raw ore with 23% P2O5 enters the crushing system. After crushing, the product particle size is -20 mm. Then it is screened by a screening machine (screen hole 3 mm). The oversize products with particle size of 3 mm - 20 mm enter the heavy medium beneficiation process. After heavy medium separation, concentrates with 26.22% P2O5 and tailings with 6.74% P2O5 are obtained respectively. The tailings after heavy medium beneficiation can be used as building materials.

[0036] The second stage of beneficiation process - optoelectronic beneficiation: The concentrates with 26.22% P2O5 after heavy medium beneficiation enter the optoelectronic beneficiation process, and concentrates with 28.85% P2O5 and tailings with 23.26% P2O5 are obtained respectively.

[0037] The third stage of beneficiation process - double reverse flotation beneficiation:

[0038] The concentrates with 28.85% P2O5 from optoelectronic beneficiation and the -3 mm undersize products from the screening machine (with 26.83% P2O5) enter the grinding process together. After grinding to 55% of the ore particle size reaching -200 mesh, they enter the double reverse flotation process, and high-quality concentrates with 35.8% P2O5 and tailings with 11.46% P2O5 are obtained respectively. The tailings from optoelectronic beneficiation are ground until 70% of the ore particle size reaches -200 mesh and then enter the double reverse flotation process, and concentrates with 30.0% P2O5 and tailings with 12.25% P2O5 are obtained respectively. The tailings from the two-stage double reverse flotation are combined into the final tailings with 11.80% P2O5.

[0039] Comparative example 1, directly using the double reverse flotation process for beneficiation experiments on high-aluminum and high-silicon phosphate ore:

[0040] The beneficiation process of a phosphate ore dressing plant in Hubei with high aluminum and high silicon adopts the double reverse flotation process: The raw ore with 24% P2O5 and a particle size of -350 mm enters the crushing system and adopts a two-stage one-closed-circuit crushing process. After crushing, the product particle size is -15 mm. The crushed product enters a one-stage closed-circuit grinding (a closed-circuit cycle composed of an overflow ball mill and a hydrocyclone group) operation to make the particle size reach 70% of -200 mesh. The beneficiation adopts the double reverse flotation process, that is, a two-roughing, two-scavenging desilication and deiron-aluminum reverse flotation process flow and a two-roughing, one-scavenging demagnesium reverse flotation process flow. The desilication and deiron-aluminum reverse flotation process flow consists of two-stage roughing and two-stage scavenging processes, and the beneficiation is carried out under weakly alkaline conditions. The demagnesium reverse flotation process flow consists of two-stage roughing and one-stage scavenging processes, and the beneficiation is carried out under weakly acidic conditions.

[0041] The final concentrate product obtained: P2O5 30.5%, yield γ = 63.17%, recovery rate ε = 80.28%. The final tailings product obtained: P2O5 12.85%, yield γ = 36.83%, recovery rate ε = 19.72%.

[0042] For the flotation reagents, sulfuric acid is used as the regulator, and amines and fatty acids are used as the collectors for separating silicon-iron-aluminum and magnesium respectively.

[0043] From the data comparison of Example 1, Example 2 and Comparative Example 1, it can be seen that the present invention can effectively solve the problem of difficult separation of high-aluminum and high-silicon phosphate ores, and can obtain some phosphorus concentrates with a grade of over 36%. Moreover, it reduces the stockpile of flotation tailings, lowers the cost of subsequent tailings treatment, and achieves the purpose of grading utilization of ores. This process responds to the national policies of environmental protection, cost reduction in production, and rational utilization of phosphate ore tailings.

[0044] Example 3, a separation method for high-aluminum and high-silicon phosphate ores, mainly including three-stage separation operation flows of gravity separation, optoelectronic separation and flotation:

[0045] (1) The raw ore enters the crushing system. After the ore is crushed, it is screened by a screening machine. The oversize products enter the heavy medium beneficiation process; after heavy medium separation, heavy medium concentrate and heavy medium tailings are obtained respectively;

[0046] (2) The heavy medium concentrate enters the optoelectronic beneficiation process to obtain optoelectronic concentrate and optoelectronic tailings respectively;

[0047] (3) The optoelectronic concentrate and the undersize products of the screening machine enter the grinding process together. After grinding to an ore particle size of 55% -200 mesh, they enter the double reverse flotation process to obtain flotation concentrate I and flotation tailings I respectively;

[0048] (4) The optoelectronic tailings are ground. After grinding to an ore particle size of 70% -200 mesh, they also enter the double reverse flotation process to obtain flotation concentrate II and flotation tailings II respectively; Flotation tailings I and flotation tailings II are combined into the final tailings.

[0049] In step (1): The raw ore enters the crushing system and is crushed to a product particle size of -20 mm, and then screened by a screening machine with a screen hole of 3 mm to obtain oversize products of 3 mm - 20 mm and undersize products of -3 mm. The composition of the raw ore is P2O5 18 - 24%, MgO ≤2%, Fe2O3 + Al2O3 4 - 8%, SiO2 4 - 8%. The dosage of flotation reagents in the double reverse flotation process is: 6.5 kg / t of raw ore of phosphoric acid with P2O5 49.43%, 0.35 kg / t of raw ore of ether polyamine as the silicon collector, 2.4 kg / t of raw ore of phosphate as the regulator, and 0.7 kg / t of raw ore of PA-69 fatty acid.

[0050] By utilizing the specific gravity difference between phosphate and gangue minerals, according to Archimedes' law, particles with a specific gravity less than that of the heavy medium will float in the medium, while particles with a specific gravity greater than that of the heavy medium will sink in the medium. The specific method of electro-optical separation is as follows: After the ore is crushed to the particle size required by the electro-optical separator to effectively dissociate phosphate from gangue minerals, the elemental atomic density in the raw ore is measured using X-rays, and phosphate minerals and high-silica minerals are distinguished based on the density difference. The specific method of flotation is as follows: In an alkaline or acidic pulp, by utilizing the difference in floatability between phosphate-containing minerals and silicate gangue minerals or carbonate gangue minerals, concentrates and tailings are obtained respectively by adding flotation reagents.

[0051] The present invention can effectively recover medium- and low-grade phosphate ores and classify phosphate ores. It can not only obtain high-quality concentrates but also improve the recovery rate. Heavy medium separation is used to reject tailings in advance, and the particle size for separation is from 0 - 20 mm. All raw ores are processed, and the tailings can be used as building materials, which not only reduces the subsequent tailings treatment cost but also improves the utilization value of the tailings; electro-optical separation further classifies the heavy medium concentrates to obtain higher-grade concentrates; rejecting tailings in advance can reduce the amount of ore entering the grinding process. High- and low-grade concentrates are separately floated. The grinding particle size of high-grade ore is coarser, saving energy consumption. It can effectively solve the difficult problem of the beneficiation process for medium- and low-grade phosphate ores with high aluminum and high silicon. This process has a high safety factor, is easy to be environmentally friendly, and is easy to industrialize, with remarkable economic and social benefits.

Claims

1. A separation method for high-aluminum, high-silicon and high-phosphorus ore, characterized in that, This method mainly includes three-stage separation operation processes of re-election, electro-optical separation and flotation: (1) The raw ore enters the crushing system. After the ore is crushed, it is screened by a screening machine. The oversize product enters the dense medium separation process; after dense medium separation, the re-election concentrate and the re-election tailings are obtained respectively; (2) The re-election concentrate enters the electro-optical separation process, and the electro-optical separation concentrate and the electro-optical separation tailings are obtained respectively; (3) The electro-optical separation concentrate and the undersize product of the screening machine enter the grinding process together. After grinding to an ore particle size of -200 mesh 54-57%, they enter the double reverse flotation process, and the flotation concentrate I and the flotation tailings I are obtained respectively; (4) The electro-optical separation tailings are ground. After grinding to an ore particle size of -200 mesh 70-75%, they also enter the double reverse flotation process, and the flotation concentrate II and the flotation tailings II are obtained respectively; The flotation tailings I and the flotation tailings II are combined into the final tailings; The composition of the raw ore is: P2O5 18-24%, MgO ≤2%, Fe2O3 + Al2O3 4-8%, SiO2 4-8%.

2. The separation method for high-aluminum, high-silicon and high-phosphorus ore according to claim 1, wherein: In step (1): The raw ore enters the crushing system and is crushed to a product particle size of -20 mm, and then screened by a screening machine with a screen hole of 3 mm to obtain an oversize product of 3 mm-20 mm and an undersize product of -3 mm.

3. The sorting method for high-aluminum high-silicon phosphate ore according to claim 1, wherein: In step (3): The electro-optical separation concentrate and the undersize product of the screening machine enter the grinding process together. After grinding to an ore particle size of -200 mesh 55%, they enter the double reverse flotation process.

4. The separation method for high-aluminum high-silicon phosphate ore according to claim 1, characterized in that: In step (4): The electro-optical separation tailings are ground. After grinding to an ore particle size of -200 mesh 70%, they also enter the double reverse flotation process.

5. The separation method for high-aluminum high-silicon phosphate ore according to claim 1, characterized in that: In step (3) or (4), the dosage of the flotation reagents in the double reverse flotation process is: phosphoric acid containing 49.43% P2O5 6.5-6.8 kg / t of raw ore, silicon collector ether polyamine 0.35-0.4 kg / t of raw ore, regulator phosphate 2.4-2.6 kg / t of raw ore, PA-69 fatty acid 0.7-0.9 kg / t of raw ore.

6. The sorting method for high-aluminum and high-silicon phosphate ore according to claim 5, characterized in that: In step (3) or (4), the dosage of the flotation reagents in the double reverse flotation process is: phosphoric acid containing 49.43% P2O5 6.5 kg / t of raw ore, silicon collector ether polyamine 0.35 kg / t of raw ore, regulator phosphate 2.4 kg / t of raw ore, PA-69 fatty acid 0.7 kg / t of raw ore.

7. The separation method for high-aluminum, high-silicon and high-phosphorus ore according to any one of claims 1-6, characterized in that: The specific re-election method is as follows: Utilizing the specific gravity difference between phosphate and gangue minerals, according to Archimedes' law, particles smaller than the density of the dense medium will float in the medium, and particles larger than the density of the dense medium will sink in the medium.

8. The separation method for high-aluminum, high-silicon and high-phosphorus ore according to any one of claims 1-6, characterized in that: The specific electro-optical separation method is as follows: After the ore is crushed, it reaches the particle size required by the electro-optical separator, enabling the effective dissociation of phosphate and gangue minerals. The elemental atomic density in the raw ore is measured by X-ray, and phosphate minerals and high-silica minerals are distinguished according to the density difference.

9. The beneficiation method for high-aluminum, high-silicon and high-phosphorus ore according to any one of claims 1-6, characterized in that: The specific flotation method is as follows: In an alkaline or acidic pulp, by utilizing the difference in the floatability between phosphate-containing minerals and silicate gangue minerals or carbonate gangue minerals, concentrates and tailings are obtained respectively by adding flotation reagents.