A composite beneficiation method for removing iron, aluminum, silicon, and magnesium impurities from phosphate rock.

Abstract

This invention relates to the field of phosphate rock beneficiation technology. It discloses a composite beneficiation method for removing iron, aluminum, silicon, and magnesium impurities from phosphate rock, comprising the following steps: S1, crushing and grinding phosphate rock to remove magnesium; S2, adding water to the demagnesified phosphate concentrate at a concentration controlled at 15-20%, and classifying it using a hydrocyclone to obtain coarse and fine products; S3, subjecting the coarse product to aeration reverse flotation for desiliconization; S4, concentrating the fine product and then subjecting it to aeration flotation for desiliconization, iron removal, and aluminum removal; S5, merging high-quality phosphate concentrate one and high-quality phosphate concentrate two to obtain a low-silicon, low-magnesium, low-iron, and low-aluminum high-quality phosphate concentrate; S6, merging the tailings as total tailings. This invention effectively solves the problem of high magnesium, silicon, iron, and aluminum impurity content in phosphate rock due to depletion, which is difficult to effectively remove. It is an easy-to-operate and easily industrialized composite beneficiation process for efficient phosphate rock impurity removal.

Description

Technical Field

[0001] This invention relates to the field of phosphate rock beneficiation technology, and in particular to a composite beneficiation method for removing iron, aluminum, silicon and magnesium impurities from phosphate rock. Background Technology

[0002] The main impurities in phosphate rock are iron, aluminum, magnesium, and silicon. In wet-process phosphoric acid production, iron-containing minerals primarily increase acid consumption and also affect the color of phosphoric acid and downstream products. Aluminum-containing minerals easily form microcrystals during phosphoric acid production, affecting filtration and quality. Magnesium-containing carbonate minerals increase acid consumption, and the resulting magnesium salts have high solubility in phosphoric acid, impacting downstream product quality. Siliceous and silicate minerals easily produce silica gel during wet-process phosphoric acid production, clogging the phosphogypsum filter cloth, affecting phosphoric acid concentration, and even impacting phosphoric acid quality. Therefore, wet-process phosphoric acid production urgently requires the removal of impurities such as iron, aluminum, magnesium, and silicon as much as possible. Thus, it is necessary to remove these impurities from the ore beneficiation process. Summary of the Invention

[0003] The purpose of this invention is to provide a composite beneficiation method for removing iron, aluminum, silicon, and magnesium impurities from phosphate rock, thereby solving the technical problem that existing phosphate rocks, which are mainly used for magnesium removal, have high iron and aluminum content, making it difficult to produce high-end phosphate products.

[0004] The present invention provides a composite beneficiation method for removing iron, aluminum, silicon, and magnesium impurities from phosphate rock, characterized by comprising the following steps:

[0005] S1, collophane is crushed and ground to a particle size of -0.075mm with a content greater than 80%, and the pulp concentration is 26-30%. Inhibitors and collectors are added to the pulp to remove dolomite minerals, resulting in demagnesized phosphate concentrate with a P2O5 content greater than 27%, MgO content less than 0.8%, Fe2O3 content 0.8-2%, Al2O3 content 0.9-3.3%, and a demagnesification rate greater than 90%.

[0006] S2. The concentration of water added to the demagnesified phosphate concentrate is controlled at 15-20%, and the ore is classified using a hydrocyclone to obtain coarse and fine products.

[0007] S3. The coarse-grained product obtained after step S2 is slurry-conditioned with dodecylamine cationic collector, followed by aeration reverse flotation desilication to obtain high-quality phosphate concentrate with P2O5 content greater than 30%, MgO content less than 1.0%, Fe2O3 content less than 0.6%, and Al2O3 content less than 0.8%.

[0008] S4. The fine-grained product obtained in step S2 is concentrated to a pulp concentration of 20% ± 2%. Sodium carbonate, water glass, and a positive flotation mixed collector are added separately. After aeration flotation, a high-quality phosphate concentrate with P2O5 content greater than 30%, MgO content less than 0.8%, Fe2O3 content less than 0.8%, and Al2O3 content less than 1.0% is obtained.

[0009] S5. Combine the high-quality phosphate concentrate I and high-quality phosphate concentrate II obtained in steps S3 and S4 respectively to obtain a high-quality phosphate concentrate with low silicon, low magnesium, low iron and aluminum content, with P2O5 content of 30-33%, MgO content of less than 0.9%, Fe2O3 content of less than 0.6%, and Al2O3 content of less than 0.8%.

[0010] S6. Combine the demagnesium tailings obtained in step S1, the desiliconization tailings obtained in step S3, and the desiliconization and dealuminization tailings obtained in step S4 into a total tailings.

[0011] As a preferred technical solution, in step S1, the inhibitor is at least one of sulfuric acid or phosphoric acid, and the amount of inhibitor added is 12-16 kg / t of raw ore; the collector is sodium 18-carbon fatty acid, and the amount of collector added is 0.4-0.8 kg / t of raw ore.

[0012] As a preferred technical solution, in step S2, a hydrocyclone is used for classification, with the classification standard being either 400 mesh or 500 mesh. The underflow, as a coarse-grained product, has a +400 or +500 mesh particle content ≥90%, a P2O5 content greater than 27.5%, a MgO content less than 0.1%, a Fe2O3 content 0.6-1%, and an Al2O3 content 1-1.5%. The overflow, as a fine-grained product, has a content of 40-50%, a P2O5 content greater than 25%, a MgO content less than 0.6%, a Fe2O3 content 1-2%, and an Al2O3 content 1.5-3.8%.

[0013] As a preferred technical solution, the amount of dodecylamine cationic collector added in step S3 is 0.2-0.3 kg / t.

[0014] As a preferred technical solution, the positive flotation mixed collector in step S4 is a mixture of sodium oleate and oxidized paraffin soap in a 1:1 ratio, and the addition amount is 0.8-1.4 kg / t.

[0015] As a preferred technical solution, in step S4, the amount of sodium carbonate added is 6-8 kg / t and the amount of water glass added is 2-3 kg / t.

[0016] As a preferred technical solution, the phosphate rock in step S1 contains 18%–24% P2O5, 4%–8% MgO, 12%–23% SiO2, 0.6%–1.7% Fe2O3, and 0.8%–3% Al2O3.

[0017] Advantages of this invention:

[0018] This invention removes dolomite minerals from phosphate rock through reverse flotation. The resulting demagnesified phosphate concentrate is then classified. The coarse-grained ore is treated with reverse flotation to remove siliceous gangue (double reverse flotation process) to enrich the phosphate concentrate. The fine-grained ore is treated with direct flotation to remove siliceous and iron-aluminum minerals (reverse flotation process) to enrich the phosphate concentrate. Through this composite beneficiation process, most of the impurities such as magnesium, silicon, iron, and aluminum are efficiently removed, reducing the content of these impurities in the phosphate concentrate and improving its quality. Attached Figure Description

[0019] Figure 1 This is a flowchart of the present invention. Detailed Implementation

[0020] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention will be further described below with reference to specific embodiments.

[0021] The following embodiments are only for further detailed description of the present invention, but do not constitute any limitation on the present invention; the materials used in the following embodiments, unless otherwise specified, were purchased from conventional chemical reagent companies and raw material suppliers.

[0022] Example 1

[0023] The phosphate rock contained 23% P2O5, 4% MgO, 14% SiO2, 0.6% Fe2O3, and 0.8% Al2O3. After grinding to -0.075 mm using a two-stage closed ball mill, the phosphate rock contained 83% phosphate and had a concentration of 30%. 12 kg / t of sulfuric acid and 0.4 kg / t of sodium fatty acid collector were added to the raw ore, and the mixture was subjected to aeration flotation for 4 minutes to obtain a demagnesified phosphate concentrate containing 29% P2O5, 0.7% MgO, 0.8% Fe2O3, and 0.9% Al2O3.

[0024] The magnesium-phosphate concentrate was diluted with water to 20% and classified using a hydrocyclone at 500 mesh to obtain (1) a +500 mesh coarse-grained product, which was 60% of the slurry, with P2O5 content of 30%, MgO content of 0.8%, SiO2 content of 12%, Fe2O3 content of 0.6%, Al2O3 content of 0.8%, and +500 mesh particle content of 90%; (2) an overflow product, which was -500 mesh fine-grained product, which was 40% of the slurry, with P2O5 content of 26%, MgO content of 0.6%, SiO2 content of 16%, Fe2O3 content of 1.0%, and Al2O3 content of 1.4%.

[0025] The (1) 500 mesh coarse-grained product was mixed with water to a concentration of 28%, and 0.2 kg / t of dodecylamine cationic collector was added. The product was then subjected to aeration flotation to obtain a high-quality phosphate concentrate with desilication, containing 33% P2O5, 0.9% MgO, 6% SiO2, 0.5% Fe2O3, and 0.8% Al2O3. The (2) 500 mesh fine-grained product was concentrated and mixed to a concentration of 18%, and 6 kg / t of sodium carbonate, 2 kg / t of water glass, and 0.8 kg / t of positive flotation mixed collector were added. The product was then subjected to aeration flotation to obtain a high-quality phosphate concentrate with desilication, de-ironization, and dealuminization, containing 30% P2O5, 0.7% MgO, 12% SiO2, 0.6% Fe2O3, and 0.8% Al2O3. The positive flotation mixed collector was a mixture of sodium oleate and oxidized paraffin soap in a 1:1 ratio.

[0026] High-quality phosphate concentrate I and high-quality phosphate concentrate II were combined to obtain mixed total phosphate concentrate, which contained 32% P2O5, 0.65% MgO, 10% SiO2, 0.6% Fe2O3, and 0.8% Al2O3.

[0027] Example 2

[0028] The phosphate rock contained 21% P2O5, 5.5% MgO, 16% SiO2, 0.8% Fe2O3, and 1.0% Al2O3. After grinding to -0.075 mm using a two-stage closed ball mill, the phosphate rock contained 88% MgO and had a concentration of 28%. 16 kg / t of sulfuric acid and 0.8 kg / t of sodium fatty acid collector were added to the raw ore, and the mixture was subjected to aeration flotation for 6 minutes to obtain a demagnesified phosphate concentrate containing 28.5% P2O5, 0.6% MgO, 1.0% Fe2O3, and 1.2% Al2O3.

[0029] The magnesium-phosphate concentrate was diluted with water to 18% and classified using a hydrocyclone at 500 mesh to obtain (1) a +500 mesh coarse-grained product, which was 55% of the slurry, with P2O5 content of 29.5%, MgO content of 0.8%, SiO2 content of 13%, Fe2O3 content of 0.6%, Al2O3 content of 0.8%, and +500 mesh particle content of 90%; (2) an overflow product, which was -500 mesh fine-grained product, which was 45% of the slurry, with P2O5 content of 25%, MgO content of 0.6%, SiO2 content of 18%, Fe2O3 content of 1.8%, and Al2O3 content of 2.2%.

[0030] The (1) 500 mesh coarse-grained product was mixed with water to a concentration of 26%, and 0.2 kg / t of dodecylamine cationic collector was added. The product was then subjected to aeration flotation to obtain a high-quality phosphate concentrate with desilication, containing 33% P2O5, 0.8% MgO, 8% SiO2, 0.6% Fe2O3, and 0.8% Al2O3. The (2) 500 mesh fine-grained product was concentrated and mixed to a concentration of 16%, and 7 kg / t of sodium carbonate, 3 kg / t of water glass, and 1.0 kg / t of positive flotation mixed collector were added. The product was then subjected to aeration flotation to obtain a high-quality phosphate concentrate with desilication, de-ironization, and dealuminization, containing 30% P2O5, 0.7% MgO, 12% SiO2, 0.7% Fe2O3, and 0.9% Al2O3. The positive flotation mixed collector was a mixture of sodium oleate and oxidized paraffin soap in a 1:1 ratio.

[0031] High-quality phosphate concentrate I and high-quality phosphate concentrate II were combined to obtain mixed total phosphate concentrate, which contained 32% P2O5, 0.7% MgO, 10% SiO2, 0.7% Fe2O3, and 0.86% Al2O3.

[0032] Example 3

[0033] The phosphate rock contained 19% P2O5, 5.5% MgO, 20% SiO2, 1.0% Fe2O3, and 1.6% Al2O3. It was ground to -0.075 mm using a two-stage closed ball mill, resulting in a particle size of 90% and a concentration of 25%. 14 kg / t of sulfuric acid and 0.6 kg / t of sodium fatty acid collector were added to the raw ore, followed by aeration flotation for 4 minutes to obtain a demagnesified phosphate concentrate with a P2O5 content of 27.5%, MgO content of 0.7%, Fe2O3 content of 1.3%, and Al2O3 content of 2.0%.

[0034] The magnesium-phosphate concentrate was diluted with water to 15% and classified using a hydrocyclone at 400 mesh to obtain (1) a +400 mesh coarse-grained product, which was 50% of the slurry, with P2O5 content of 28.5%, MgO content of 0.8%, SiO2 content of 14%, Fe2O3 content of 0.8%, Al2O3 content of 0.9%, and +500 mesh content of 95%; (2) an overflow, which was a -500 mesh fine-grained product, which was 50% of the slurry, with P2O5 content of 24%, MgO content of 0.6%, SiO2 content of 23%, Fe2O3 content of 2.0%, and Al2O3 content of 3.0%.

[0035] The (1) 400 mesh coarse-grained product was mixed with water to a concentration of 25%, and 0.3 kg / t of dodecylamine cationic collector was added. The product was then subjected to aeration flotation to obtain a high-quality phosphate concentrate with desilication, containing 32% P2O5, 0.8% MgO, 10% SiO2, 0.6% Fe2O3, and 0.8% Al2O3. The (2) 400 mesh fine-grained product was concentrated and mixed to a concentration of 15%, and 8 kg / t of sodium carbonate, 3 kg / t of water glass, and 1.4 kg / t of positive flotation mixed collector were added. The product was then subjected to aeration flotation to obtain a high-quality phosphate concentrate with desilication, deironization, and dealuminization, containing 30% P2O5, 0.8% MgO, 13% SiO2, 0.8% Fe2O3, and 1.0% Al2O3. The positive flotation mixed collector was a mixture of sodium oleate and oxidized paraffin soap in a 1:1 ratio.

[0036] High-quality phosphate concentrate I and high-quality phosphate concentrate II were combined to obtain mixed total phosphate concentrate, which contained 31.8% P2O5, 0.8% MgO, 11% SiO2, 0.8% Fe2O3, and 0.9% Al2O3.

[0037] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.

Claims

1. A combined beneficiation method for removing iron, aluminum, silicon and magnesium impurities from phosphate ores, characterized by, The method comprises the following steps: S1, collophane is crushed and ground to a content of -0.075 mm of more than 80%, and the pulp concentration is 26-30%; an inhibitor and a collector are added to the pulp to remove dolomite minerals, and a demagnified phosphate concentrate is obtained, with a P2O5 content of more than 27%, a MgO content of less than 0.8%, a Fe2O3 content of 0.8-2%, an Al2O3 content of 0.9-3.3%, and a demagnification rate of more than 90%; S2, the demagnified phosphate concentrate is added with water to control the concentration to be 15-20%, and is classified by a cyclone to obtain coarse-grained products and fine-grained products; S3, the coarse-grained products obtained by the step S2 are added with dodecylamine amine cationic collector for slurry conditioning, and are subjected to air reverse flotation to remove silicon to obtain high-quality phosphate concentrate I, with a P2O5 content of more than 30%, a MgO content of less than 1.0%, a Fe2O3 content of less than 0.6%, and an Al2O3 content of less than 0.8%; S4, the fine-grained products obtained by the step S2 are concentrated, and the pulp concentration is controlled to be 20%±2%; sodium carbonate, water glass and positive flotation mixed collector are added respectively, and air flotation is performed to obtain high-quality phosphate concentrate II, with a P2O5 content of more than 30%, a MgO content of less than 0.8%, a Fe2O3 content of less than 0.8%, and an Al2O3 content of less than 1.0%; S5, the high-quality phosphate concentrate I and II obtained by the steps S3 and S4 are combined to obtain low-silicon, low-magnesium, low-iron and aluminum high-quality phosphate concentrate, with a P2O5 content of 30-33%, a MgO content of less than 0.9%, a Fe2O3 content of less than 0.6%, and an Al2O3 content of less than 0.8%; S6, the demagnified tailings obtained by the step S1, the desiliconized tailings obtained by the step S3, and the desiliconized and de-iron and aluminum tailings obtained by the step S4 are combined as total tailings; The inhibitor in the step S1 is at least one of sulfuric acid or phosphoric acid, and the inhibitor is added in an amount of 12-16 kg / t of raw ore; the collector is sodium 18-carbon fatty acid, and the collector is added in an amount of 0.4-0.8 kg / t of raw ore; In the step S2, the cyclone is used for classification, and the classification standard is one of 400 mesh or 500 mesh; the sand is used as coarse-grained products, with a +400 or +500 mesh content of more than 90%, a P2O5 content of more than 27.5%, a MgO content of less than 0.1%, a Fe2O3 content of 0.6-1%, and an Al2O3 content of 1-1.5%; the overflow is used as fine-grained products, with a content of 40-50%, a P2O5 content of more than 25%, a MgO content of less than 0.6%, a Fe2O3 content of 1-2%, and an Al2O3 content of 1.5-3.8%; The collophane in the step S1 has a P2O5 content of 18%-24%, a MgO content of 4%-8%, a SiO2 content of 12%-23%, a Fe2O3 content of 0.6-1.7%, and an Al2O3 content of 0.8-3%.

2. A combined beneficiation process for removal of iron, aluminium, silicon and magnesium impurities from phosphate ores as claimed in claim 1, wherein: The dodecylamine amine cationic collector in the step S3 is added in an amount of 0.2-0.3 kg / t.

3. The composite beneficiation method for removing iron, aluminum, silicon, and magnesium impurities from phosphate rock as described in claim 1, characterized in that: The mixed collector in the S4 step is a mixture of sodium oleate and oxidized paraffin soap in a ratio of 1:1, and the addition amount is 0.8-1.4 Kg / t.

4. A combined beneficiation process for removal of iron, aluminum, silicon and magnesium impurities from phosphate ores as claimed in claim 1, wherein: The addition amount of sodium carbonate in the S4 step is 6-8 Kg / t, and the addition amount of water glass is 2-3 Kg / t.

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