Composite beneficiation method for removing iron, aluminum, silicon and magnesium impurities in phosphorite

Abstract

The invention relates to the technical field of phosphorite beneficiation, and discloses a compound beneficiation method for removing iron, aluminum, silicon and magnesium impurities in phosphorite, which comprises the following steps: S1, crushing and grinding collophanite, and then removing magnesium; s2, water is added into the magnesium-removed phosphate concentrate to control the concentration to be 15-20%, a cyclone is used for grading, and a coarse-grain product and a fine-grain product are obtained; s3, the coarse fraction product is subjected to inflation reverse flotation desilicication; s4, concentrating the fine fraction product, and performing air inflation flotation to remove silicon, iron and aluminum; s5, combining the high-quality phosphate concentrate I and the high-quality phosphate concentrate II to obtain low-silicon, low-magnesium, low-iron and low-aluminum high-quality phosphate concentrate; and S6, the tailings are combined to serve as total tailings. The method can effectively solve the problems that magnesium, silicon, iron and aluminum impurities in phosphorite are high in content and difficult to effectively remove due to depletion of the phosphorite, and is a beneficiation compound process for efficient impurity removal of phosphorite, which is easy to operate and easy to industrialize.

Description

Technical Field

[0001] The present invention relates to the technical field of phosphate ore beneficiation, and in particular to a composite beneficiation method for removing iron, aluminum, silicon and magnesium impurities from phosphate ore. Background Art

[0002] The main impurities in phosphate rock include iron, aluminum, magnesium, and silicon. In wet-process phosphoric acid production, iron-containing minerals primarily increase acid consumption and can also affect the color of the phosphoric acid and downstream products. Aluminum-containing minerals easily form tiny crystals during phosphoric acid production, affecting phosphate filtration and quality. Magnesium-containing carbonate minerals not only increase acid consumption but also form magnesium salts with high solubility in phosphoric acid, affecting the quality of downstream products. Silica and silicate minerals can easily produce silica gel during wet-process phosphoric acid production, clogging phosphogypsum filter cloths, hindering phosphoric acid concentration, and even affecting 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. Therefore, it is necessary to remove impurities such as iron, aluminum, magnesium, and silicon during mineral processing. Summary of the Invention

[0003] The purpose of the present invention is to provide a composite mineral processing method for removing iron, aluminum, silicon and magnesium impurities from phosphate ore, so as to solve the technical problem that the existing phosphate ore mainly removes magnesium, but has high content of impurities such as iron and aluminum, making it difficult to produce high-end phosphate products.

[0004] The present invention provides a composite mineral processing method for removing iron, aluminum, silicon and magnesium impurities from phosphate ore, characterized in that it comprises the following steps:

[0005] S1. Collophorite is crushed and ground to a content of greater than 80% of -0.075mm and a pulp concentration of 26-30%. Inhibitors and collectors are added to the pulp to remove dolomite minerals to obtain demagnesized phosphate concentrate, which has a P2O5 content greater than 27%, a MgO content less than 0.8%, a Fe2O3 content of 0.8-2%, an Al2O3 content of 0.9-3.3%, and a demagnesization rate greater than 90%.

[0006] S2, adding water to the demagnesiumized phosphate concentrate to control the concentration at 15-20%, and using a cyclone to classify it to obtain coarse-grained products and fine-grained products;

[0007] S3. Add dodecylamine cationic collector to the coarse-grained product obtained in step S2 for slurry adjustment, and perform aeration reverse flotation for desiliconization to obtain a high-quality phosphate concentrate having a P2O5 content greater than 30%, a MgO content less than 1.0%, a Fe2O3 content less than 0.6%, and an Al2O3 content less than 0.8%;

[0008] S4. The fine-grained product obtained in step S2 is concentrated to control the pulp concentration to 20%±2%, and sodium carbonate, water glass, and a mixed collector for direct flotation are added respectively. After aeration flotation, a high-quality phosphate concentrate II having a P2O5 content greater than 30%, a MgO content less than 0.8%, a Fe2O3 content less than 0.8%, and an Al2O3 content less than 1.0% is obtained;

[0009] S5, combining the high-quality phosphate concentrate 1 and the high-quality phosphate concentrate 2 obtained in steps S3 and S4, respectively, to obtain a low-silicon, low-magnesium, low-iron, and low-aluminum high-quality phosphate concentrate having 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%;

[0010] S6. Combining the demagnesium tailings obtained in step S1, the desiliconization tailings obtained in step S3, and the desiliconization and deironization tailings obtained in step S4 as the total tailings.

[0011] As a preferred technical solution, the inhibitor in step S1 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, S2 is classified by a cyclone, and the classification standard is one of 400 mesh or 500 mesh; the sedimentation is used as a coarse-grained product, wherein the content of +400 or +500 mesh particle size is ≥90%, its P2O5 content is greater than 27.5%, its MgO content is less than 0.1%, its Fe2O3 content is 0.6-1%, and its Al2O3 content is 1-1.5%; the overflow is used as a fine-grained product, its content is 40-50%, its P2O5 content is greater than 25%, its MgO content is less than 0.6%, its Fe2O3 content is 1-2%, and its Al2O3 content is 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 mixed collector for positive flotation in step S4 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.

[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 P2O5 content in the collophosphate ore in step S1 is 18% to 24%, the MgO content is 4% to 8%, the SiO2 content is 12% to 23%, the Fe2O3 content is 0.6 to 1.7%, and the Al2O3 content is 0.8 to 3%.

[0017] Advantages of the present invention:

[0018] The present invention removes dolomite minerals from phosphate ore by reverse flotation, and the obtained demagnesized phosphate concentrate is subjected to classification operation. The coarse-grained ore is subjected to reverse flotation to remove siliceous gangue (double reverse flotation process) to enrich the phosphate concentrate; the fine-grained ore is subjected to direct flotation to remove siliceous and ferroaluminous minerals (inverse flotation process) to enrich the phosphate concentrate. Through the composite mineral processing process, most of the impurities such as magnesium, silicon, iron, and aluminum are efficiently removed, the impurity contents of magnesium, silicon, iron, and aluminum in the phosphate concentrate are reduced, and the quality of the phosphate concentrate is improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a process framework diagram of the present invention. DETAILED DESCRIPTION

[0020] In order to make the technical means, creative features, objectives and effects achieved by the present invention easier to understand, the present invention is further described below in conjunction with specific embodiments.

[0021] The following examples are intended to further illustrate the present invention but do not constitute any limitation thereto. Unless otherwise specified, the materials used in the following examples were purchased from conventional chemical reagent companies and raw material suppliers.

[0022] Example 1

[0023] The collophosphate ore contained 23% P2O5, 4% MgO, 14% SiO2, 0.6% Fe2O3, and 0.8% Al2O3. It was ground in a two-stage, two-closed ball mill to a particle size of -0.075 mm, accounting for 83% of the total particle size and 30% concentration. Sulfuric acid (12 kg / t) and sodium fatty acid (0.4 kg / t) were added to the ore, and aerated flotation was performed for 4 minutes to obtain a demagnesized phosphate concentrate with a P2O5 content of 29%, MgO content of 0.7%, Fe2O3 content of 0.8%, and Al2O3 content of 0.9%.

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

[0025] The (1) +500 mesh coarse-grained product is slurried with water to a concentration of 28%, and 0.2 kg / t of dodecylamine cationic collector is added, and aeration flotation is performed to obtain a desiliconized high-quality phosphate concentrate No. 1 with a P2O5 content of 33%, a MgO content of 0.9%, a SiO2 content of 6%, a Fe2O3 content of 0.5%, and an Al2O3 content of 0.8%. The (2) -500 mesh fine-grained product is concentrated and slurried 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 are added, and aeration flotation is performed to obtain a desiliconized, deironized, and dealuminized high-quality phosphate concentrate No. 2 with a P2O5 content of 30%, a MgO content of 0.7%, a SiO2 content of 12%, a Fe2O3 content of 0.6%, and an Al2O3 content of 0.8%. The positive flotation mixed collector is a mixture of sodium oleate and oxidized paraffin soap in a ratio of 1:1.

[0026] The high-quality phosphate concentrate 1 and the high-quality phosphate concentrate 2 are combined to obtain a mixed total phosphate concentrate, wherein the P2O5 content is 32%, the MgO content is 0.65%, the SiO2 content is 10%, the Fe2O3 content is 0.6%, and the Al2O3 content is 0.8%.

[0027] Example 2

[0028] The collophosphate ore contained 21% P2O5, 5.5% MgO, 16% SiO2, 0.8% Fe2O3, and 1.0% Al2O3. It was ground in a two-stage, two-closed ball mill to a particle size of -0.075 mm, accounting for 88% of the total particle size and 28% concentration. Sulfuric acid (16 kg / t) and sodium fatty acid (0.8 kg / t) were added, and aeration flotation was performed for 6 minutes to obtain a demagnesized phosphate concentrate with a P2O5 content of 28.5%, MgO content of 0.6%, Fe2O3 content of 1.0%, and Al2O3 content of 1.2%.

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

[0030] The (1) +500 mesh coarse-grained product is slurried with water to a concentration of 26%, and 0.2 kg / t of dodecylamine cationic collector is added, and aeration flotation is performed to obtain a desiliconized high-quality phosphate concentrate No. 1 with a P2O5 content of 33%, a MgO content of 0.8%, a SiO2 content of 8%, a Fe2O3 content of 0.6%, and an Al2O3 content of 0.8%. The (2) -500 mesh fine-grained product is concentrated and slurried 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 are added, and aeration flotation is performed to obtain a desiliconized, deironized, and dealuminized high-quality phosphate concentrate No. 2 with a P2O5 content of 30%, a MgO content of 0.7%, a SiO2 content of 12%, a Fe2O3 content of 0.7%, and an Al2O3 content of 0.9%. The positive flotation mixed collector is a mixture of sodium oleate and oxidized paraffin soap in a ratio of 1:1.

[0031] The high-quality phosphate concentrate 1 and the high-quality phosphate concentrate 2 are combined to obtain a mixed total phosphate concentrate, wherein the P2O5 content is 32%, the MgO content is 0.7%, the SiO2 content is 10%, the Fe2O3 content is 0.7%, and the Al2O3 content is 0.86%.

[0032] Example 3

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

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

[0035] The (1) +400 mesh coarse-grained product is slurried with water to a concentration of 25%, and 0.3 kg / t of dodecylamine cationic collector is added, and aeration flotation is performed to obtain a desiliconized high-quality phosphate concentrate No. 1 with a P2O5 content of 32%, a MgO content of 0.8%, a SiO2 content of 10%, a Fe2O3 content of 0.6%, and an Al2O3 content of 0.8%. The (2) -400 mesh fine-grained product is concentrated and slurried 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 are added, and aeration flotation is performed to obtain a desiliconized, deironized, and dealuminized high-quality phosphate concentrate No. 2 with a P2O5 content of 30%, a MgO content of 0.8%, a SiO2 content of 13%, a Fe2O3 content of 0.8%, and an Al2O3 content of 1.0%. The positive flotation mixed collector is a mixture of sodium oleate and oxidized paraffin soap in a ratio of 1:1.

[0036] The high-quality phosphate concentrate 1 and the high-quality phosphate concentrate 2 are combined to obtain a mixed total phosphate concentrate, wherein the P2O5 content is 31.8%, the MgO content is 0.8%, the SiO2 content is 11%, the Fe2O3 content is 0.8%, and the Al2O3 content is 0.9%.

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

Claims

1. A composite mineral processing method for removing iron, aluminum, silicon and magnesium impurities from phosphate ore, characterized in that: The following steps are involved: S1. Collophanite is crushed and ground to a content of greater than 80% at -0.075 mm and a pulp concentration of 26-30%. Inhibitors and collectors are added to the pulp to remove dolomite minerals to obtain demagnesified phosphate concentrate, wherein the P2O5 content is greater than 27%, the MgO content is less than 0.8%, the Fe2O3 content is 0.8-2%, the Al2O3 content is 0.9-3.3%, and the demagnesization rate is greater than 90%; S2, adding water to the de-magnesiumized phosphate concentrate to control the concentration to 15-20%, and using a cyclone to classify to obtain a coarse particle product and a fine particle product; S3, adding dodecylamine cationic collector to the coarse-grained product obtained in step S2 for slurry adjustment, aerating reverse flotation for desiliconization, and obtaining a high-quality phosphate concentrate with a P2O5 content greater than 30%, a MgO content less than 1.0%, a Fe2O3 content less than 0.6%, and an Al2O3 content less than 0.8%; S4, the fine-grained product obtained in step S2 is concentrated, the pulp concentration is controlled to be 20%±2%, sodium carbonate, water glass, and positive flotation mixed collector are added respectively, and high-quality phosphate concentrate II with a P2O5 content greater than 30%, a MgO content less than 0.8%, a Fe2O3 content less than 0.8%, and an Al2O3 content less than 1.0% is obtained after aeration flotation; S5, combining the high-quality phosphate concentrate 1 and the high-quality phosphate concentrate 2 obtained in steps S3 and S4, respectively, to obtain a low-silicon, low-magnesium, low-iron, and low-aluminum high-quality phosphate concentrate having 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. Combining the demagnesium tailings obtained in step S1, the desiliconization tailings obtained in step S3 and the desiliconization and deironization tailings obtained in step S4 as the total tailings.

2. A composite mineral processing method for removing iron, aluminum, silicon and magnesium impurities from phosphate ore according to claim 1, characterized in that: In the step S1, the inhibitor is at least one of sulfuric acid or phosphoric acid, and the amount of the inhibitor added is 12-16 kg / t of the original ore. The collector is sodium 18-carbon fatty acid, and the amount of the collector added is 0.4-0.8 kg / t of the original ore.

3. A composite mineral processing method for removing iron, aluminum, silicon and magnesium impurities from phosphate ore according to claim 1, characterized in that: The S2 is classified by a cyclone, and the classification standard is one of 400 mesh or 500 mesh; the sedimentation is taken as a coarse-grained product, wherein the content of +400 or +500 mesh is ≥90%, and its P2O5 content is greater than 27.5%, MgO content is less than 0.1%, Fe2O3 content is 0.6-1%, and Al2O3 content is 1-1.5%; the overflow is taken as a fine-grained product, and its content is 40-50%, and its P2O5 content is greater than 25%, MgO content is less than 0.6%, Fe2O3 content is 1-2%, and Al2O3 content is 1.5-3.8%.

4. A composite mineral processing method for removing iron, aluminum, silicon and magnesium impurities from phosphate ore according to claim 1, characterized in that: In the step S3, the amount of dodecylamine cationic collector added is 0.2-0.3 Kg / t.

5. A composite mineral processing method for removing iron, aluminum, silicon and magnesium impurities from phosphate ore according to claim 1, characterized in that: In the step S4, the mixed collector for positive flotation is a mixture of sodium oleate and oxidized paraffin soap in a ratio of 1:1, and the added amount is 0.8-1.4 Kg / t.

6. A composite mineral processing method for removing iron, aluminum, silicon and magnesium impurities from phosphate ore according to claim 1, characterized in that: In the 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.

7. A composite mineral processing method for removing iron, aluminum, silicon and magnesium impurities from phosphate ore according to claim 1, characterized in that: The collophanite in step S1 has a P2O5 content of 18% to 24%, a MgO content of 4% to 8%, a SiO2 content of 12% to 23%, a Fe2O3 content of 0.6% to 1.7%, and an Al2O3 content of 0.8% to 3%.

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