Beneficiation method for high-magnification semi-oxide silicon-calcium collophanite

Abstract

The invention relates to a beneficiation method for high-power semi-oxide silicon-calcium collophanite, and belongs to the field of mineral processing. The method comprises the following steps: crushing raw ore, carrying out ultrafine crushing and screening, carrying out ore grinding and grading, and carrying out reselection to obtain reselected concentrate and reselected tailings; carrying out reverse flotation dealumination and magnesium removal on the gravity concentrate, and dehydrating to obtain gravity concentrate flotation concentrate; and re-concentration and ore grinding operation is carried out on the re-concentration flotation tailings, dewatering is carried out, re-concentration flotation tailings filter cakes are mixed with underflow of a re-concentration tailings thickener, then grinding and grading are carried out, reverse flotation magnesium removal operation is carried out, and reverse flotation concentrate is obtained. According to the method, the energy consumption of the whole grinding process is effectively reduced, a good separation environment is provided for subsequent flotation, raw ore is divided into high-magnesium and high-silicon phosphorite and low-magnesium and low-silicon phosphorite through reselection and preselection, the low-magnesium and low-silicon phosphorite is subjected to a single reverse flotation synchronous magnesium, aluminum and iron removal process, and the low-magnesium and low-silicon phosphorite is obtained. A single reverse flotation magnesium removal process is adopted for the high-magnesium and high-silicon phosphorite, high-quality and high-utilization and low-quality and low-utilization of the phosphorite are achieved, the beneficiation technological process is stable, the separation effect is good, and the recovery rate is high.

Description

Technical Field

[0001] The invention belongs to the technical field of mineral processing, and in particular relates to a beneficiation method for high-sesquioxide calcareous silicate collophosphate. Background Art

[0002] In my country, phosphate rock resources primarily consist of sedimentary phosphate rocks, primarily low- and medium-grade collophanites. Some high-grade siliceous collophanites contain high levels of aluminum and iron sesquioxides (R2O3). Traditional wet phosphoric acid production has clear requirements for these levels: Class I phosphate concentrates must not contain more than 2.5% of these sesquioxides, while Class II concentrates must not contain more than 3.0%. The iron and aluminum oxide content in phosphate rock is often expressed as R2O3 (R represents Fe and Al, i.e., Fe2O3 + Al2O3). Iron and aluminum not only interfere with the growth of calcium sulfate crystals but also cause phosphoric acid to form sludge. Phosphate rock reacts with acid to form water-insoluble complex phosphates. These phosphates, when precipitated or removed with gypsum, result in significant losses of P2O5. The resulting complex phosphates of iron and aluminum form fine crystals, increasing the viscosity of solutions and slurries and easily clogging filter cloths and filter cake pores. These phosphates also complicate post-processing, such as the concentration and drying of phosphoric acid or ammonium phosphate slurries, leading to poor product properties and reduced quality. Therefore, to minimize the impact on wet-process phosphoric acid and acid-process fertilizer production, it is necessary to minimize the content of iron and aluminum sesquioxides in phosphate concentrate.

[0003] Currently, the conventional processes for high-aluminum, high-iron, low-grade calcareous silicate phosphate ores are direct-reverse flotation and pre-desliming-double-reverse flotation. The direct-reverse flotation process suffers from drawbacks such as fine grinding fineness, fine concentrate product particle size, difficulty in concentrate transportation and dewatering, and high concentrate beneficiation costs. Furthermore, direct-reverse flotation requires the use of a tailings pond for normal operation, making it difficult for new phosphate plants to obtain approval for tailings ponds. The pre-desliming-double-reverse flotation process, on the other hand, suffers from poor reagent selectivity, a significant impact of ore slime on the process, significant P2O5 losses during desliming, and ultimately low P2O5 recovery in the concentrate. Summary of the Invention

[0004] The present invention is mainly devoted to addressing the deficiencies of the existing technology and proposes a more reasonable and efficient beneficiation method for removing carbonate, iron-containing and aluminum-containing gangue minerals from calcareous siliceous collophosphate.

[0005] The present invention is a beneficiation method for high-sesquioxide calcareous silicate collophosphate, which is characterized by the following steps: (1) The raw ore is crushed in a conventional way and then fed into an ultra-fine crushing and screening system consisting of a high-pressure roller and a vibrating screen for further ultra-fine crushing. The qualified material is fed into the powder ore bin; (2) The materials at the bottom of the powder ore bin are fed into the grinding and classification process through the feeder, and the qualified materials obtained after classification are fed into the gravity separation buffer tank; (3) The slurry in the gravity separation buffer tank is fed to the gravity separation process through a conveying pump to obtain gravity separation concentrate and gravity separation tailings; (4) The gravity separation concentrate is fed into the buffer tank of the gravity separation reverse flotation synchronous impurity removal operation, and the gravity separation flotation concentrate is fed into the gravity separation flotation concentrate dehydration operation. The filtrate of the gravity separation flotation concentrate dehydration operation is returned to the reverse flotation dealumination return water tank, and the filter cake of the gravity separation flotation concentrate is used as a low-grade concentrate product to supply the downstream wet-process phosphoric acid unit; (5) The heavy flotation tailings are fed into the heavy flotation tailings dewatering operation, and the heavy flotation tailings dewatering operation returns to the gravity separation and grinding operation. The filter cake of the heavy flotation tailings is mixed with the underflow of the gravity separation tailings thickener and fed into the tailings regrinding and classification operation. The ground slurry is fed into the reverse flotation demagnesium operation buffer tank; the reverse flotation tailings are fed into the reverse flotation tailings dewatering operation, and the filter cake of the reverse flotation tailings dewatering operation is fed into the downstream filling operation. The reverse flotation concentrate is a high-grade concentrate product and can be used for the downstream yellow phosphorus raw material pellet production device; (6) Build three return water pools to store reverse flotation desiliconization return water, reverse flotation demagnesium return water and gravity separation return water respectively; The ore composition of the high-sesquioxide siliceous-calcium collophosphate is as follows: P2O5 grade is 27.5%~29.8%, MgO mass content is 1.1%~2.5%, SiO2 mass content is 11.5%~14.5%, Al2O3 mass content is 1.5%~3.0%, and Fe2O3 mass content is 1.2%~2.5%.

[0006] The above-mentioned beneficiation method for high-sesquioxide calcareous silicate collophosphate has a further preferred technical solution: the ore is crushed to -3mm by ultra-fine crushing, the ultra-fine crushing adopts a high-pressure roller mill, and the vibrating screen adopts a relaxation screen.

[0007] The above-mentioned beneficiation method for high-sesquioxide calcareous silicate collophosphate, a further preferred technical solution is: the grinding and classification operation adopts a rod mill or a grate ball mill, and adopts a two-stage classification: the first stage adopts a micro powder screen or a fine screen with a sieve aperture size controlled at 0.1~0.15mm, and the second stage adopts a cyclone classification with a classification particle size controlled at 74μm; the grinding fineness of the material before flotation is controlled at 55%~65%.

[0008] The above-mentioned beneficiation method for high-sesquioxide calcareous silicate phosphate, a further preferred technical solution is: the gravity separation operation adopts two-stage classification plus one-stage gravity separation, the two-stage classification adopts a cyclone + a micro powder screen, the cyclone is controlled at 10~38μm, and the micro powder screen is controlled at 0.5~1mm. The gravity separation uses one or a combination of two of an interference bed, a shaking table, a spiral chute, a belt chute and a centrifugal concentrator, and the gravity separation operation includes roughing, cleaning or scavenging.

[0009] The above-mentioned beneficiation method for high-sesquioxide calcareous silicate collophosphate, a further preferred technical solution is: the heavy fine flotation tailings and the reverse flotation demagnesization process of the gravity separation tailings mainly remove carbonate-containing minerals, the inhibitor is sulfuric acid, phosphoric acid, phosphate or a combination of the above agents, the collector is fatty acid soap, and the reverse flotation demagnesization operation includes roughing, scavenging, and concentration or a combination thereof.

[0010] The beneficiation method for high-sesquioxide calcareous collophosphate described above has a further preferred technical solution: a single reverse flotation synchronous impurity removal process for the gravity concentrate, the flotation environment is an acidic or weakly acidic environment, the adjusting agent is selected from one of inorganic acids or organic acids such as sulfuric acid, phosphoric acid, hydrochloric acid, and oxalic acid, or a combination of the above agents, the dealuminizing collector is selected from one of fatty amines, polyamines, etheramines, amides, polyamine ethers, and quaternary ammoniums, the demagnesizing collector is selected from weak anions such as phosphates and polyoxyethylene esters, and the deferrifying collector is selected from xanthates and sulfur-nitrogen sulfide ore collectors. The collectors can be added simultaneously or in steps during the roughing operation, and the reverse flotation operation includes roughing, scavenging, and concentration, or a combination thereof.

[0011] A further preferred technical solution of the above-mentioned beneficiation method for high-sesquioxide calcareous silicate collophosphate is as follows: the regrinding and classification operation adopts a tower mill for grinding, and the grinding fineness is 85% to 95% of -200 mesh.

[0012] The above-mentioned beneficiation method for high-sesquioxide calcareous silicate collophosphate, a further preferred technical solution is: the return water from the gravity separation return water tank is used for the primary grinding operation and gravity separation operation, the return water from the reverse flotation demagnesium return water tank is used for the reverse flotation demagnesium operation and regrinding operation, and the return water from the reverse flotation synchronous impurity removal return water tank is used for the reverse flotation synchronous impurity removal operation.

[0013] The above-mentioned beneficiation method for high-sesquioxide calcareous silicate phosphate, a further preferred technical solution is: the dehydration operation of the heavy fine flotation concentrate, the dehydration operation of the heavy fine flotation tailings, the dehydration operation of the heavy tailings flotation concentrate, and the dehydration operation of the heavy tailings flotation tailings adopt one or two dehydration processes of thickening and filtration.

[0014] The high-grade collophanite concentrate obtained by the method of the present invention has a P2O5 grade of 31.5% to 33.5%, a MgO content of 0.5% to 0.8%, and an aluminum-iron sesquioxide (R2O3) content of 1.8% to 2.6%. The low-grade collophanite concentrate obtained has a P2O5 grade of 24.00% to 26.00%, a MgO content of 0.5% to 1.0%, and a SiO2 content of 18% to 26%.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The method of the present invention is aimed at the high-sesquioxide siliceous-calcium collophosphate with a single mineral composition, wherein the phosphorus-containing minerals are mainly low-carbon fluoroapatite, a small amount of carbonapatite and apatite, the magnesium-containing gangue minerals are mainly divided into carbonate minerals, the aluminum-containing gangue minerals are mainly clay silicate minerals such as hydromica and kaolin, as well as feldspar, quartz and siliceous gangue, and the iron-containing gangue minerals are mainly pyrite. Among them, collophosphate, quartz and feldspar have poor grindability and coarse dissociation particle size, while dolomite, hydromica, kaolin and pyrite have good grindability and fine dissociation particle size. Conventional crushing and grinding process is prone to over-grinding. Adding a section of high-pressure roller ultra-fine crushing operation between fine crushing and grinding can improve the particle size composition of subsequent grinding products and provide a good sorting environment for subsequent gravity separation. After gravity separation, they are divided into two grades of products: high-magnesium and high-silicon phosphate ore and low-magnesium and low-silicon phosphate ore. Low-magnesium and low-silicon phosphate ore has good ore selectivity and coarse dissociation particle size. High-quality phosphate concentrate can be obtained by synchronous impurity removal process, while high-magnesium and high-silicon phosphate ore has poor selectivity and fine dissociation particle size, but high silicon content. After simple magnesium removal and pelletizing, it can be used as a high-quality raw material for yellow phosphate ore, truly achieving the purpose of making full use of phosphate minerals.

[0016] The return water process of the present invention adopts separate return water, and the waste water generated by each operation is returned to the respective operation as much as possible through thickening, thereby effectively avoiding interference between different mineral processing processes.

[0017] Compared with the conventional forward-reverse flotation process or the double reverse flotation process, the process of the present invention has the advantages of stable mineral processing process, good separation effect, high recovery rate, etc. DETAILED DESCRIPTION

[0018] Example 1, a beneficiation method for high-sesquioxide calcareous silicate collophosphate, the steps of which are as follows: (1) The feed particle size of the raw ore is -600mm. Conventional crushing adopts three-stage open circuit crushing. The first stage crushing adopts jaw crusher, and the last two stages crushing adopt cone crusher to crush the material to -30mm. The crushed material is fed to the screening operation before fine crushing. The screening equipment uses relaxation screen. The material on the screen is fed to the high-pressure roller mill. The material after high-pressure roller crushing returns to the screening operation to form closed-circuit ultra-fine crushing and screening. The material under the screen is fed to the powder ore bin, and the screening particle size is controlled at -3mm.

[0019] (2) The material at the bottom of the powder ore bin is quantitatively fed to the grinding and classification operation through a disc feeder. The grinding method is single-stage grinding, and the classification method is primary pre-classification and secondary control classification. The disc feeder adopts variable frequency speed regulation. The grinding operation adopts a grid-type ball mill. The primary pre-classification adopts a hydrocyclone. The secondary control classification operation adopts two-stage classification. The particle size of the primary pre-classification and the secondary cyclone classification is controlled at 74μm. The first stage adopts a micro powder screen, and the sieve hole particle size is controlled at 0.15mm. The grinding fineness of the material before gravity separation is controlled at 60%. The particle size that passes the classification operation is fed into the gravity separation operation buffer tank; (3) The slurry in the gravity separation buffer tank is fed to the gravity separation operation through a conveying pump to obtain gravity separation concentrate and gravity separation tailings. The conveying pump adopts variable frequency speed regulation. The gravity separation operation adopts two-stage classification plus one-stage gravity separation. The two-stage classification adopts a cyclone + a micro powder screen. The cyclone is controlled at 38μm and the micro powder screen is controlled at 0.5mm. The gravity separation adopts a spiral chute for primary roughing and a spiral chute for primary scavenging, and finally produces gravity separation concentrate and gravity separation tailings. (4) The gravity separation concentrate is fed into the reverse flotation synchronous impurity removal slurry buffer tank. The flotation environment is a weakly acidic environment. Sulfuric acid is used as the pH adjuster, etheramine is used as the dealumination collector, phosphate is used as the demagnesium collector, and butyl xanthate is used as the deferrification collector. The collectors are added at the same time. The reverse flotation operation includes one roughing selection and one scavenging selection.

[0020] (5) The gravity separation tailings are fed into the gravity separation tailings thickener, and the gravity separation concentrate is fed into reverse flotation. The tailings with simultaneous impurity removal are fed into the gravity separation tailings dewatering operation. The filter cake of the dewatering operation is mixed with the underflow of the gravity separation tailings thickener and then fed into the tailings regrinding operation. The regrinding and classification operation uses a tower mill for grinding to achieve further dissociation of useful minerals and gangue minerals. The grinding fineness is -200 mesh 85%. The ground slurry is fed into the reverse flotation demagnesization operation. Sulfuric acid is used as the inhibitor and PA-64 as the collector. The reverse flotation demagnesization operation adopts one roughing and two scavenging operations.

[0021] (6) The dewatering operation of heavy fine flotation concentrate, the dewatering operation of heavy fine flotation tailings, the dewatering operation of heavy tailings flotation concentrate and the dewatering operation of heavy tailings flotation tailings all adopt two dewatering processes, namely, thickening and filtration. The overflow and filtrate of the dewatering operation are respectively returned to their own return water tanks.

[0022] (7) The whole plant has three return water tanks, which are used to store gravity separation return water, reverse flotation demagnesium return water and reverse flotation dealuminization return water respectively. The return water from the gravity separation return water tank can be used for primary grinding and gravity separation operations, the return water from the reverse flotation demagnesium return water tank can be used for reverse flotation demagnesium operations and regrinding operations, and the return water from the reverse flotation dealuminization return water tank can be used for reverse flotation dealuminization operations.

[0023] The ore composition of the high-sesquioxide type collophanite in the above method is 29.46% P2O5, 1.65% MgO, 15.80% SiO2, 3.34% Al2O3, and 1.38% Fe2O3. The high-grade collophosphate concentrate obtained by the above method has a P2O5 grade of 33.50%, a MgO mass content of 0.55%, and a sesquioxide (R2O3) mass content of 1.95%.

[0024] The low-grade collophosphate concentrate obtained by the above method has a P2O5 grade of 25.32% and a MgO mass content of 0.75%.

[0025] Example 2, a beneficiation method for high-sesquioxide calcareous silicate collophosphate, the steps of which are as follows: (1) The feed particle size of the raw ore is -350mm. Conventional crushing adopts two-stage open-circuit crushing. The first stage crushing adopts jaw crusher and the second stage crushing adopts cone crusher to crush the material to -30mm. The crushed material is fed to the screening operation before fine crushing. The screening equipment uses relaxation screen. The material on the screen is fed to the high-pressure roller mill. The material after high-pressure roller crushing is returned to the screening operation to form a closed-circuit ultra-fine crushing and screening. The material under the screen is fed to the powder ore bin. The screening particle size is controlled at -3mm.

[0026] (2) The material at the bottom of the powder ore bin is quantitatively fed to the grinding and classification operation through a disc feeder. The grinding adopts a single-stage grinding method, and the classification adopts a single-stage control classification method. The disc feeder adopts variable frequency speed regulation, the grinding operation adopts a rod mill, and the single-stage control classification operation adopts cyclone classification. The classification particle size is controlled at 74μm, and the grinding fineness of the material before gravity separation is controlled at 65%. The particle size that passes the classification operation is fed into the gravity separation operation buffer tank; (3) The slurry in the gravity separation buffer tank is fed to the gravity separation operation through a conveying pump to obtain gravity separation concentrate and gravity separation tailings. The conveying pump adopts variable frequency speed regulation. The gravity separation operation adopts one-stage classification plus one-stage gravity separation. The classification adopts a cyclone, and the cyclone is controlled at 38μm. The gravity separation adopts interference bed one-time roughing and spiral chute one-time scavenging, and finally produces gravity separation concentrate and gravity separation tailings. (4) The gravity separation concentrate is fed into the reverse flotation synchronous impurity removal slurry buffer tank. The flotation environment is a weakly acidic environment. Oxalic acid is used as the pH adjuster, quaternary ammonium salt is used as the dealumination collector, organic phosphate is used as the demagnesium collector, and butyl xanthate is used as the deferrification collector. The collectors are added in batches, first adding organic phosphate and xanthate, and then adding quaternary ammonium salt. The reverse flotation operation includes one roughing selection, one scavenging selection and one cleaning selection.

[0027] (5) The gravity separation tailings are fed into the gravity separation tailings thickener, and the gravity separation concentrate is fed into the reverse flotation. The tailings with simultaneous impurity removal are fed into the gravity separation tailings dewatering operation. The filter cake of the dewatering operation is mixed with the underflow of the gravity separation tailings thickener and then fed into the tailings regrinding operation. The regrinding and classification operation uses a tower mill for grinding to achieve further dissociation of useful minerals and gangue minerals. The grinding fineness is -200 mesh 85%. The ground slurry is fed into the reverse flotation demagnesization operation. Oxalic acid is used as the inhibitor and PA-67 as the collector. The reverse flotation demagnesization operation adopts one roughing selection, two scavenging selections and one concentrating selection.

[0028] (6) The dewatering operation of heavy fine flotation concentrate, the dewatering operation of heavy fine flotation tailings, the dewatering operation of heavy tailings flotation concentrate and the dewatering operation of heavy tailings flotation tailings all adopt two dewatering processes, namely, thickening and filtration. The overflow and filtrate of the dewatering operation are respectively returned to their own return water tanks.

[0029] (7) The whole plant has three return water tanks, which are used to store gravity separation return water, reverse flotation demagnesium return water and reverse flotation dealuminization return water respectively. The return water from the gravity separation return water tank can be used for primary grinding and gravity separation operations, the return water from the reverse flotation demagnesium return water tank can be used for reverse flotation demagnesium operations and regrinding operations, and the return water from the reverse flotation dealuminization return water tank can be used for reverse flotation dealuminization operations.

[0030] The ore composition of the high-sesquioxide type collophanite in the above method is 27.98% P2O5, 1.75% MgO, 16.5% SiO2, 3.45% Al2O3, and 1.65% Fe2O3. The high-grade collophosphate concentrate obtained by the above method has a P2O5 grade of 32.50%, a MgO mass content of 0.75%, and a sesquioxide (R2O3) mass content of 2.05%.

[0031] The low-grade collophosphate concentrate obtained by the above method has a P2O5 grade of 24.61% and a MgO mass content of 0.85%.

[0032] Example 3, a beneficiation method for high-sesquioxide calcareous silicate collophosphate, the steps of which are as follows: (1) The feed particle size of the raw ore is -500mm. Conventional crushing adopts three-stage open circuit crushing. The first stage crushing adopts hammer crusher and the second stage crushing adopts cone crusher to crush the material to -20mm. The crushed material is fed to fine crushing operation. The screening equipment uses relaxation screen. The material on the screen is fed to high pressure roller mill and the material under the screen is fed to powder ore bin. The screening particle size is controlled at -3mm.

[0033] (2) The material at the bottom of the powder ore bin is quantitatively fed to the grinding and classification operation through a disc feeder. The grinding method is single-stage grinding, and the classification method is primary pre-classification and secondary control classification. The disc feeder adopts variable frequency speed regulation. The grinding operation adopts a rod mill or a grate ball mill. The primary pre-classification adopts a hydrocyclone, and the secondary control classification operation adopts cyclone classification. The classification particle size is controlled at 74μm, and the grinding fineness of the material before gravity separation is controlled at 55%. The particle size that passes the classification operation is fed into the gravity separation operation buffer tank; (3) The slurry in the gravity separation buffer tank is fed to the gravity separation operation through a conveying pump to obtain gravity separation concentrate and gravity separation tailings. The conveying pump adopts variable frequency speed regulation. The gravity separation operation adopts two-stage classification plus one-stage gravity separation. The two-stage classification adopts a cyclone + a micro powder screen. The cyclone is controlled at 38μm and the micro powder screen is controlled at 0.5mm. The gravity separation adopts a spiral chute for primary roughing and a spiral chute for primary scavenging, and finally produces gravity separation concentrate and gravity separation tailings. (4) The re-selected concentrate is fed into the reverse flotation synchronous impurity removal slurry buffer tank. The flotation environment is a weakly acidic environment. Phosphoric acid is used as the pH adjuster, polyamine is used as the dealumination collector, polyoxyethylene esters are used as the demagnesium collector, and butyl xanthate is used as the deferrification collector. The collectors are added in batches. First, polyoxyethylene esters and butyl xanthate are mixed and added, and then quaternary ammonium salts are added. The reverse flotation operation includes one roughing selection, one scavenging selection and one cleaning selection.

[0034] (5) The gravity separation tailings are fed into the gravity separation tailings thickener, and the gravity separation concentrate is fed into the reverse flotation. The tailings with simultaneous impurity removal are fed into the gravity separation tailings dewatering operation. The filter cake of the dewatering operation is mixed with the underflow of the gravity separation tailings thickener and then fed into the tailings regrinding operation. The regrinding and classification operation uses a tower mill for grinding to achieve further dissociation of useful minerals and gangue minerals. The grinding fineness is -200 mesh 90%. The ground slurry is fed into the reverse flotation demagnesization operation. Oxalic acid is used as the inhibitor and PA-67 as the collector. The reverse flotation demagnesization operation adopts one roughing, two scavenging and one concentrating.

[0035] (6) The dewatering operation of heavy fine flotation concentrate, the dewatering operation of heavy fine flotation tailings, the dewatering operation of heavy tailings flotation concentrate and the dewatering operation of heavy tailings flotation tailings all adopt two dewatering processes, namely, thickening and filtration. The overflow and filtrate of the dewatering operation are respectively returned to their own return water tanks.

[0036] (7) The whole plant has three return water tanks, which are used to store gravity separation return water, reverse flotation demagnesium return water and reverse flotation dealuminization return water respectively. The return water from the gravity separation return water tank can be used for primary grinding and gravity separation operations, the return water from the reverse flotation demagnesium return water tank can be used for reverse flotation demagnesium operations and regrinding operations, and the return water from the reverse flotation dealuminization return water tank can be used for reverse flotation dealuminization operations.

[0037] The ore composition of the high-sesquioxide type collophanite in the above method is P2O5 grade of 28.58%, MgO mass content of 1.35%, SiO2 mass content of 15.20%, Al2O3 mass content of 2.95%, and Fe2O3 mass content of 1.58%; The high-grade collophosphate concentrate obtained by the above method has a P2O5 grade of 32.75%, a MgO mass content of 0.5%, and a sesquioxide (R2O3) mass content of 1.95%.

[0038] The low-grade collophosphate concentrate obtained by the above method has a P2O5 grade of 24.85% and a MgO mass content of 0.75%.

[0039] Example 4, a comparative experiment on the beneficiation method of high-sesquioxide calcareous silicate collophosphate: The direct-reverse flotation process and the double reverse flotation process are consistent with the crushing and dehydration process adopted in the present invention, and the main difference is the subsequent grinding and sorting process. The specific implementation methods are as follows: (1) Crushing and screening: The feed particle size of the raw ore is -350mm. Conventional crushing adopts two-stage open circuit crushing. The first stage crushing adopts jaw crusher and the second stage crushing adopts cone crusher to crush the material to -30mm. The crushed material is fed to the screening operation before fine crushing. The screening equipment uses relaxation screen. The material on the screen is fed to the high-pressure roller mill. The material after high-pressure roller crushing is returned to the screening operation to form closed-circuit ultra-fine crushing and screening. The material under the screen is fed to the powder ore bin. The screening particle size is controlled at -3mm.

[0040] (2) Grinding process: Double reverse flotation is the same as the grinding process of the process of the present invention, both using a one-stage grinding and classification process, while direct and reverse flotation uses a two-stage grinding process.

[0041] Comparison Example 1: Positive and negative processes: The material at the bottom of the powder ore bin is quantitatively fed to the grinding and classification process via a disc feeder. Two-stage grinding is used, and the disc feeder adopts variable frequency speed regulation. A grate ball mill is used for the first stage of grinding, and an overflow ball mill is used for the second stage of grinding. The classification particle size is controlled at 74μm and the grinding fineness is controlled at 85%. The qualified particle size of the classification process is fed into the flotation buffer tank. Comparative Example 2: Double-reverse process: Single-stage grinding is used for grinding, primary controlled classification is used for classification, variable frequency speed regulation is used for the disc feeder, a rod mill is used for grinding, cyclone classification is used for primary controlled classification, the classification particle size is controlled at 74μm, the grinding fineness of the material before gravity separation is controlled at 65%, and the qualified particle size of the classification operation is fed into the reverse flotation demagnesium operation buffer tank; Experimental example: The process of the present invention: the ore grinding adopts one-stage grinding, the classification adopts one-time controlled classification, the disc feeder adopts frequency conversion speed regulation, the grinding operation adopts rod mill, the one-time controlled classification operation adopts cyclone classification, the classification particle size is controlled at 74μm, the grinding fineness of the material before gravity separation is controlled at 65%, and the particle size that passes the classification operation is fed into the gravity separation operation buffer tank.

[0042] (3) Separation process: Direct flotation and reverse flotation are used to remove magnesium first and then remove silicon by reverse flotation. Double reverse flotation is used to remove mud first, and the demudified pulp is reverse flotated to remove magnesium and silicon in sequence. The present invention adopts gravity separation first and then separate flotation.

[0043] Comparative Method Example 1: Direct and reverse processes: The ground pulp is fed into the direct flotation process. The flotation environment is a weakly alkaline environment. Sodium carbonate is used as the pH adjuster, water glass is used as the depressant, 2# medicine is used as the forward flotation collector, and the collector is added in batches. The forward flotation operation includes one roughing, one scavenging, and one cleaning. The foam from the forward flotation is fed into the reverse flotation for magnesium removal. The flotation environment is a weakly acidic environment. Phosphoric acid is used as the pH adjuster, PA-67 is used as the magnesium removal collector, and the collector is added in batches. The reverse flotation operation includes one roughing, two scavengings, and one cleaning. The tailings from the forward flotation, the tailings from the reverse flotation, and the concentrate from the reverse flotation are fed into the subsequent dewatering operation. Comparative Method Example 2: Double Reverse Process: The ground pulp is fed to the desliming operation, and a hydrocyclone is used for desliming to remove -38μm ore slime. The deslimed pulp is fed to the reverse flotation demagnesing process. The flotation environment is a weakly acidic environment. Phosphoric acid is used as the pH adjuster. The demagnesing collector is PA-67. The collector is added in batches. The reverse flotation operation includes one roughing, two scavenging and one concentrating. The product in the reverse flotation demagnesing tank is fed to the reverse flotation desiliconization operation. The flotation environment is a weakly alkaline environment. Sodium carbonate is used as the pH adjuster. MAC is used as the reverse flotation collector. The collector is added in batches. The forward flotation operation includes one roughing, one scavenging and one concentrating. The reverse flotation demagnesing tailings, reverse flotation desiliconization tailings, reverse flotation desiliconization concentrate and ore slime are fed to the subsequent dewatering operation. Experimental example: The process of the present invention: the slurry in the gravity separation buffer tank is fed to the gravity separation operation via a delivery pump to obtain gravity separation concentrate and gravity separation tailings. The delivery pump adopts variable frequency speed regulation. The gravity separation operation adopts one-stage classification plus one-stage gravity separation. The classification adopts a cyclone, and the cyclone is controlled at 38μm. The gravity separation adopts an interference bed for one roughing selection and a spiral chute for one scavenging selection, and finally produces gravity separation concentrate and gravity separation tailings; the gravity separation concentrate is fed into a reverse flotation synchronous impurity removal slurry buffer tank, the flotation environment is a weakly acidic environment, phosphorus is selected as a pH adjuster, MAC is selected as a desiliconization collector, and PA-64 is selected as a demagnesium collector. The collectors are added in batches, first adding PA-64 and then adding MAC. The reverse flotation operation includes one roughing selection, one scavenging selection and one concentrating selection. The gravity separation tailings are fed into the gravity separation tailings thickener, and the gravity separation concentrate is fed into reverse flotation. The tailings with simultaneous impurity removal are fed into the gravity separation tailings dewatering operation. The filter cake of the dewatering operation is mixed with the underflow of the gravity separation tailings thickener and then fed into the tailings regrinding operation. The regrinding and classification operation uses a tower mill for grinding to further separate useful minerals and gangue minerals. The grinding fineness is 85% at -200 mesh. The ground slurry is fed into the reverse flotation demagnesization operation. Phosphoric acid is used as the inhibitor and PA-67 as the collector. The reverse flotation demagnesization operation adopts one roughing operation, two scavenging operations and one cleaning operation.

[0044] (4) Thickening and filtration: The dewatering operation of fine tailings adopts two dewatering processes, thickening and filtration. The overflow and filtrate of the dewatering operation are respectively returned to the return water tank.

[0045] The ore composition of the high-sesquioxide type collophanite in the above method is as follows: P2O5 grade is 27.98%, MgO mass content is 1.75%, SiO2 mass content is 16.5%, Al2O3 mass content is 3.45%, and Fe2O3 mass content is 1.65%.

[0046] Analysis: Since forward and reverse flotation uses two-stage grinding and the flotation process requires heated flotation for large flotation volumes, the process flow is complex, and the energy consumption and reagent costs are high. The cost is about twice that of double reverse flotation and the combined gravity flotation-separation flotation process of the present invention, and the investment is 20% higher than the same period last year. The present invention uses gravity separation to discard some difficult-to-select clay gangue minerals in advance, improves subsequent flotation, and adopts a desiliconization and demagnesium single flotation process. The process flow is simple, the reagent consumption is small, and the mineral processing cost is reduced by 1 / 3.

[0047] The high-grade collophanite concentrate obtained by the present invention has a P2O5 grade of 32.50%, a MgO content of 0.75%, and a sesquioxide (R2O3) content of 2.05%, with a recovery rate of approximately 63%. The low-grade collophanite concentrate has a P2O5 grade of 24.61%, a MgO content of 0.85%, and a recovery rate of approximately 29.5%. The high-grade phosphate concentrate can be used to produce high-grade monoammonium phosphate products, while the low-grade phosphate concentrate can be used for wet-process phosphoric acid.

[0048] Comparative Example 1: The collophosphate concentrate obtained by direct and reverse flotation contained a P₂O₅ grade of 31.00%, a MgO content of 0.95%, and a sesquioxide (R₂O₃) content of 2.35%, with a recovery rate of approximately 80%. This phosphate concentrate can be used in subsequent wet-process phosphoric acid processes.

[0049] Comparative Example 2: The collophosphate concentrate obtained by double reverse flotation contained a P₂O₅ grade of 31.50%, a MgO content of 0.85%, and a sesquioxide (R₂O₃) content of 2.20%, with a recovery rate of approximately 60%. This phosphate concentrate can be used in subsequent wet-process phosphoric acid processes.

[0050] The following table compares the costs of the process of the present invention with those of conventional forward and reverse flotation processes and double reverse flotation processes: .

Claims

1. A beneficiation method for high-sesquioxide calcareous silicate collophosphate, characterized in that: The steps are as follows: (1) The raw ore is crushed in a conventional way and then fed into an ultra-fine crushing and screening system consisting of a high-pressure roller and a vibrating screen for further ultra-fine crushing. The qualified material is fed into the powder ore bin; (2) The materials at the bottom of the powder ore bin are fed into the grinding and classification process through the feeder, and the qualified materials obtained after classification are fed into the gravity separation buffer tank; (3) The slurry in the gravity separation buffer tank is fed to the gravity separation process through a conveying pump to obtain gravity separation concentrate and gravity separation tailings; (4) The gravity separation concentrate is fed into the buffer tank of the gravity separation reverse flotation synchronous impurity removal operation, and the gravity separation flotation concentrate is fed into the gravity separation flotation concentrate dehydration operation. The filtrate of the gravity separation flotation concentrate dehydration operation is returned to the reverse flotation dealumination return water tank, and the filter cake of the gravity separation flotation concentrate is used as a low-grade concentrate product to supply the downstream wet-process phosphoric acid unit; (5) The heavy flotation tailings are fed into the heavy flotation tailings dewatering operation, and the heavy flotation tailings dewatering operation returns to the gravity separation and grinding operation. The heavy flotation tailings filter cake is mixed with the gravity separation tailings thickener underflow and then fed into the tailings regrinding and classification operation. The ground slurry is fed into the reverse flotation demagnesium operation buffer tank; The reverse flotation tailings are fed into the reverse flotation tailings dewatering process, and the filter cake from the reverse flotation tailings dewatering process is fed into the downstream filling process. The reverse flotation concentrate is a high-grade concentrate product that can be used by the downstream yellow phosphorus raw material pellet production unit. (6) Build three return water pools to store reverse flotation desiliconization return water, reverse flotation demagnesium return water and gravity separation return water respectively; The ore composition of the high-sesquioxide siliceous-calcium collophosphate is as follows: P2O5 grade is 27.5%~29.8%, MgO mass content is 1.1%~2.5%, SiO2 mass content is 11.5%~14.5%, Al2O3 mass content is 1.5%~3.0%, and Fe2O3 mass content is 1.2%~2.5%.

2. The mineral processing method according to claim 1, wherein: The ultra-fine crushing operation crushes the ore to -3mm. The ultra-fine crushing adopts high-pressure roller mill and the vibrating screen adopts relaxation screen.

3. The mineral processing method according to claim 1, wherein: The grinding and classification operation uses a rod mill or a grate ball mill, and adopts a two-stage classification: the first stage uses a micro-powder screen or a fine screen, and the screen hole particle size is controlled at 0.1~0.15mm; the second stage uses a cyclone classification, and the classification particle size is controlled at 74μm; the grinding fineness of the material before flotation is controlled at 55%~65%.

4. The mineral processing method according to claim 1, wherein: Gravity separation adopts two-stage classification plus one-stage gravity separation. The two-stage classification adopts cyclone + micro powder screen. The cyclone is controlled at 10~38μm, and the micro powder screen is controlled at 0.5~1mm. Gravity separation uses one or a combination of interference bed, shaking table, spiral chute, belt chute and centrifugal concentrator. Gravity separation operation includes roughing, cleaning or scavenging.

5. The mineral processing method according to claim 1, wherein: The reverse flotation demagnesization process of heavy fine flotation tailings and gravity separation tailings mainly removes carbonate minerals. The inhibitors are sulfuric acid, phosphoric acid, phosphates or a combination of the above agents. The collector is fatty acid soap. The reverse flotation demagnesization operation includes roughing, scavenging, and concentration or a combination of them.

6. The mineral processing method according to claim 1, wherein: The single reverse flotation synchronous impurity removal process of gravity concentrate adopts an acidic or weakly acidic flotation environment. The adjusting agent is selected from inorganic acids or organic acids such as sulfuric acid, phosphoric acid, hydrochloric acid, oxalic acid, or a combination of the above agents. The dealumination collector is selected from fatty amines, polyamines, etheramines, amides, polyamine ethers, and quaternary ammonium. The demagnesization collector is selected from weak anions such as phosphates and polyoxyethylene esters. The deferrification collector is selected from xanthates and sulfur-nitrogen sulfide ore collectors. The collectors can be added simultaneously or in steps during the roughing operation. The reverse flotation operation includes roughing, scavenging, and concentrate, or a combination of them.

7. The mineral processing method according to claim 1, wherein: The regrinding and classification operation uses a tower mill for grinding, and the grinding fineness is 85%~95% of -200 mesh.

8. The mineral processing method according to claim 1, wherein: The return water from the gravity separation return water tank is used for the first stage grinding operation and gravity separation operation, the return water from the reverse flotation demagnesium return water tank is used for the reverse flotation demagnesium operation and regrinding operation, and the return water from the reverse flotation synchronous impurity removal return water tank is used for the reverse flotation synchronous impurity removal operation.

9. The mineral processing method according to claim 1, wherein: The dewatering operation of heavy fine flotation concentrate, the dewatering operation of heavy fine flotation tailings, the dewatering operation of heavy tailings flotation concentrate and the dewatering operation of heavy tailings flotation tailings adopt one or a combination of thickening and filtration dewatering processes.