Equal floatable separation process for improving phosphorus recovery rate of micro-fine particle collophanite

Abstract

The invention relates to an equal floatable separation process for improving the phosphorus recovery rate of micro-fine particle collophanite. According to the technical scheme, the method comprises the steps that phosphoric ore pulp is introduced into isolatable flotation operation, a fatty acid anion collecting agent and an amine cation collecting agent are synchronously added into the phosphoric ore pulp, isolatable flotation is carried out, an in-tank product I and a foam product I are obtained, and the foam product I is phosphate concentrate I; the product I in the tank is introduced into reverse flotation roughing operation, a regulator and an amine cation collecting agent are added into the product I in the tank for roughing, a product II in the tank and a foam product II are obtained, the product II in the tank is phosphate concentrate II, and the phosphate concentrate I and the phosphate concentrate II are combined into phosphate concentrate; introducing the foam product II into the first scavenging operation for scavenging to obtain a product III in the tank and a foam product III, returning the product III in the tank to the previous step to enter the roughing operation together with the product I in the tank, introducing the foam product III into the second scavenging operation for scavenging to obtain a product IV in the tank and a foam product IV, and returning the product III in the tank to the next step to enter the roughing operation together with the product I in the tank. The product IV in the tank returns to the last step and enters the first scavenging operation together with the foam product II, and the foam product IV is phosphate tailings. According to the method, the natural floatability of the micro-fine-particle collophanite is fully utilized, the phosphorus recovery rate of the micro-fine-particle collophanite is increased to 85% or above, and the method has the advantages of being small in flotation reagent dosage, high in phosphorus recovery rate and high in mineral separation efficiency.

Description

Technical Field

[0001] The invention belongs to the technical field of phosphate ore separation, and in particular relates to an isoflurane separation process for improving the phosphorus recovery rate of micro-grained colloidal phosphate ore. Background Art

[0002] Phosphate is an important strategic resource of the country. Most of the phosphate rock in my country is medium-low grade collophosphate with fine particles. This kind of phosphate resource has high requirements for grinding fineness. Low grinding fineness is a necessary condition for its monomer dissociation. The flotation of fine-grained materials has the problems of great separation difficulty, low sorting efficiency and high phosphorus loss during the sorting process. The main reasons are the following two points: First, the fine particles have a large specific surface area and significantly increase the surface energy. Under certain conditions, non-selective mutual condensation is prone to occur between the surfaces of different minerals. At the same time, due to the large surface energy of fine particles, although they have a high adsorption force on reagents, they have poor selective adsorption, which makes it difficult to selectively separate fine particles; second, the fine particles are small in mass. When colliding with bubbles, it is not easy to overcome the resistance of the hydration layer between the mineral particles and the bubbles, and it is difficult to attach to the bubbles.

[0003] At present, the technological measures to solve the problem of fine particle flotation mainly start from reagents, such as selective flocculation flotation, carrier flotation, agglomeration flotation, etc.

[0004] (Li Donglian, Wang Qiao, Ma Xiaoshuang. Effect of a polymer flocculant on flotation of fine-grained colloidal phosphate [J]. Journal of Wuhan University of Technology, 2015, 11.) Taking Jinning high-silica gel phosphate ore as the research object, a non-ionic polymer flocculant F-08 was added to conduct direct flotation and reverse flotation experiments. In the direct flotation roughing, the grade of phosphorus pentoxide in the phosphate concentrate increased from 23.99% to 24.54%, and the recovery rate increased from 80.80% to 85.30%; in the reverse flotation roughing, the grade of phosphorus pentoxide in the phosphate concentrate increased from 21.50% to 22.95%, and the recovery rate increased from 65.32% to 70.48%. During the sorting process, the grade of phosphorus pentoxide in the phosphate concentrate was less than 25%, the increase was not large, and the phosphorus recovery rate did not have a significant advantage.

[0005] The patented technology of "A flotation process for fine-grained phosphate ore" (CN110369152B) discloses a flotation process for fine-grained phosphate ore, which includes the following steps: 1) Ball milling: repeatedly ball mill the phosphate ore through a ball mill and a spiral classifier, and grind it to the required fineness; 2) Reverse flotation decarbonization and demagnesiumization: add water to adjust the slurry, and carry out decarbonization flotation at pH5.4 to pH5.8 to reduce the influence of organic carbon on flotation desiliconization and demagnesiumization; 3) Direct flotation desiliconization: add sodium carbonate to adjust the decarbonization and demagnesium concentrate slurry, and carry out desiliconization flotation at pH9.5 to pH9.8; 4) Reverse flotation demagnesiumization: add phosphoric acid to adjust the desiliconization concentrate slurry, and carry out demagnesiumization flotation at pH5.3 to pH5.6. This invention can effectively recover useful minerals from fine-grained phosphate ore, but the sorting process is too long and the amount of reagents is large, making it difficult to industrialize. Summary of the invention

[0006] The present invention aims to address the deficiencies of the prior art and aims to provide a separation method which is stable, has an efficient process structure, uses a small amount of reagents, can effectively improve the phosphorus recovery rate of fine-grained phosphate ore, and realizes efficient enrichment of fine-grained phosphate minerals.

[0007] To achieve the above-mentioned purpose, an isoflurane separation process for improving the phosphorus recovery rate of fine-grained colloidal phosphate ore is disclosed. The specific steps of the technical solution adopted by the process are: introducing phosphate ore pulp into an isoflurane operation, and simultaneously adding fatty acid anion collectors and amine cationic collectors to the phosphate ore pulp, wherein the mass ratio of the added fatty acid anion collectors to the amine cationic collectors is 2.0 / 1.0-3.5 / 1.0, and the total amount of collectors added per ton of ore pulp dry basis is 0.05-0.15 kg; performing isoflurane flotation to obtain a tank product I and a foam product I, wherein the foam product I is a phosphate concentrate I; introducing the tank product I into a reverse flotation roughing operation, and adding a regulator and an amine cationic collector to the tank product I, wherein the mass ratio of the added fatty acid anion collectors to the amine cationic collectors is 2.0 / 1.0-3.5 / 1.0, and the total amount of collectors added per ton of ore pulp dry basis is 0.05-0.15 kg. The amount of adjusting agent added is 4.0~6.0kg, and the amount of amine cationic collector added is 0.2~0.35kg, and roughing is carried out to obtain in-tank product II and foam product II. In-tank product II is phosphate concentrate II, and phosphate concentrate I and phosphate concentrate II are combined into phosphate concentrate; foam product II is introduced into the first scavenging operation, and scavenging is carried out to obtain in-tank product III and foam product III. In-tank product III returns to the previous step and enters the roughing operation together with in-tank product I, foam product III is introduced into the second scavenging operation, and scavenging is carried out to obtain in-tank product IV and foam product IV, in-tank product IV returns to the previous step and enters the first scavenging operation together with foam product II, and foam product IV is phosphate tailings.

[0008] In the above scheme, the phosphate slurry has a P2O5 grade of 22.0~28.0wt%, a MgO content of 0.8~1.5wt%, an Al2O3 content of 2.0~4.5wt%, a particle size of less than 0.025mm accounting for 50~70wt%, and a concentration of 18~25wt%.

[0009] In the above scheme, the difference in P2O5 grade between the phosphate concentrate I and the phosphate concentrate II is less than 2%, the P2O5 grade of the phosphate concentrate is ≥28.5wt%, and the MgO content is ≤0.8wt%. It is further preferred that the P2O5 grade difference between the phosphate concentrate I and the phosphate slurry II is less than 1%.

[0010] In the above scheme, the adjusting agent is composed of the following components in mass percentage: 25-30% phosphoric acid, 13-17% sulfuric acid, 30-40% iron-free aluminum sulfate, and 6-20% polyethylene glycol, and the sum of the mass percentages of the components is 100%.

[0011] The adoption of the above technical solution has the following positive effects: 1. The invention makes full use of the natural floatability of fine-grained collophanites, and floats the easily floatable minerals first. In the collophanites, the floatability of the minerals is in the order of dolomite minerals>colllophanites>siliceous minerals. After adding fatty acid collectors and amine collectors, the essence of the equal floatability separation process is to first float out the easily floatable dolomite minerals and some fine-grained collophanites, as well as the mud, suspended particles and some small amounts of ultra-fine-grained siliceous minerals mixed in the phosphate slurry after the early grinding. Since the phosphate slurry selected in the present invention has a MgO content of 0.8-1.5wt%, the equal floatation operation has a pre-selection effect in the present invention. First, the mud, suspended and ultrafine particles that affect the subsequent flotation are removed in advance to ensure the high sorting of the subsequent flotation; second, a part of the fine-grained collophosphate ore is collected in advance. The P2O5 grade difference between the phosphate concentrate I and the phosphate concentrate II is less than 2%, and further less than 1%. Then, the phosphate concentrate I and the phosphate slurry II can be combined into a phosphate concentrate, and the P2O5 grade of the phosphate concentrate is guaranteed to be ≥27.5, thereby improving the yield of the phosphate concentrate.

[0012] 2. The amount of flotation reagent is small. In order to ensure the iso-floatable pre-selection effect of the present invention, only a small amount of collector needs to be added to the iso-floatable process to float out some fine-grained collophanite, ultra-fine-grained siliceous minerals, and gangue minerals such as dolomite minerals, mud, and suspended particles. In the subsequent flotation operation, without the interference of these ultra-fine materials, adding an appropriate amount of selection reagent can obtain good process indicators, and the amount of reagent can be greatly reduced.

[0013] 3. The present invention adopts a mixture of sulfuric acid, phosphoric acid, iron-free aluminum sulfate and polyethylene glycol as a regulator, firstly to adjust the pH value of the slurry, and secondly to adjust the foam toughness, so as to improve the fluidity of the flotation foam, facilitate transportation, and avoid the problem of difficult foam accumulation and transportation difficulties.

[0014] 4. The addition method of the regulator and collector adopted in the present invention can achieve the simultaneous removal of magnesium and aluminum in phosphate minerals, avoiding the low flotation efficiency and complicated recycling of return water.

[0015] 5. The P2O5 grade of the phosphate concentrate obtained in the specific implementation manner of the present invention is ≥27.5%, and the phosphorus recovery rate is ≥85%.

[0016] Therefore, the present invention has the characteristics of stable process structure, high efficiency, high phosphorus recovery rate, small reagent consumption and low mineral processing cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The present invention is a flow chart of an isoflurane separation process for improving the phosphorus recovery rate of fine-grained colloidal phosphate. DETAILED DESCRIPTION

[0018] In order to better understand the present invention, the content of the present invention is further explained below in conjunction with the examples, but the content of the present invention is not limited to the following examples. Any simple modification and equivalent structural transformation or modification made according to the essential content of the present invention should be included in the protection scope of the present invention.

[0019] Unless otherwise specified in the following examples, the reagents used are commercially available chemical reagents or industrial products.

[0020] In the following examples, the adjusting agent is composed of the following components in the following mass percentages: 30% phosphoric acid, 15% sulfuric acid, 35% iron-free aluminum sulfate, and 20% polyethylene glycol.

[0021] The fatty acid anion scavenger used in the embodiment of the present invention is a fatty acid saponification compound, which is prepared by firstly subjecting cottonseed oil to a saponification reaction with a sodium hydroxide solution, and then compounding the saponified product with a nonionic surfactant, Tween-80.

[0022] The amine cationic collector used in the embodiment of the present invention is a compound of N-(2-hydroxy-1,1-dimethylethyl) dodecylamine, a nonionic surfactant, sorbitan oleate, and a C7-C9 high-carbon fatty alcohol.

[0023] Example 1 A floatable separation process for improving the phosphorus recovery rate of fine-grained colloidal phosphate. The phosphate slurry described in this embodiment has a P2O5 grade of 26.0-28.0wt%, a MgO content of 0.8-1.5wt%, an Al2O3 content of 2.0-3.0wt%, a particle size of less than 0.025mm accounting for 55t%, and a concentration of 22-25wt%. Figure 1 As shown, the technical scheme described in this embodiment is: introducing phosphate slurry into iso-floatable operation, adding fatty acid anion collector and amine cationic collector to the phosphate slurry simultaneously, wherein the mass ratio of the added fatty acid anion collector to the added amine cationic collector is 3.0 / 1.0, and the total amount of collector added per ton of dry pulp is 0.1 kg, and iso-floatable flotation is performed to obtain product I in the tank and foam product I, and the foam product I is phosphate concentrate I; The product I in the tank is introduced into a reverse flotation roughing operation, and a regulator and an amine cationic collector are added to the product I in the tank, wherein the amount of the regulator added per ton of dry basis of phosphate ore pulp is 6.0 kg, and the amount of the amine cationic collector added is 0.2 kg, and roughing is performed to obtain a tank product II and a foam product II, wherein the tank product II is phosphate concentrate II, and the phosphate concentrate I and the phosphate concentrate II are combined into a phosphate concentrate; The foam product II is introduced into the first scavenging operation for scavenging to obtain the in-tank product III and the foam product III. The in-tank product III returns to the previous step and enters the roughing operation together with the in-tank product I. The foam product III is introduced into the second scavenging operation for scavenging to obtain the in-tank product IV and the foam product IV. The in-tank product IV returns to the previous step and enters the first scavenging operation together with the foam product II. The foam product IV is the phosphate tailings.

[0024] In this embodiment, the P2O5 grade of phosphate concentrate I is controlled to be 30.02, and the P2O5 grade of phosphate concentrate II is controlled to be 31.93 during flotation; the P2O5 grade of the phosphate concentrate is 31.13%, the MgO content is 0.68%, the Al2O3 content is 2.36%, and the P2O5 recovery rate is 89.67%.

[0025] Example 2 A floatable separation process for improving the phosphorus recovery rate of fine-grained colloidal phosphate. The phosphate slurry described in this embodiment has a P2O5 grade of 26.0-28.0wt%, a MgO content of 0.8-1.5wt%, an Al2O3 content of 2.0-3.0wt%, a particle size of less than 0.025mm accounting for 63t%, and a concentration of 22-25wt%. Figure 1As shown, the technical scheme described in this embodiment is: introducing phosphate slurry into iso-floatable operation, adding fatty acid anion collector and amine cationic collector to the phosphate slurry simultaneously, wherein the mass ratio of the added fatty acid anion collector to the added amine cationic collector is 3.0 / 1.0, and the total amount of collector added per ton of dry pulp is 0.1 kg, and iso-floatable flotation is performed to obtain product I in the tank and foam product I, and the foam product I is phosphate concentrate I; The product I in the tank is introduced into a reverse flotation roughing operation, and a regulator and an amine cationic collector are added to the product I in the tank, wherein the amount of the regulator added per ton of dry basis of phosphate ore pulp is 6.0 kg, and the amount of the amine cationic collector added is 0.2 kg, and roughing is performed to obtain a tank product II and a foam product II, wherein the tank product II is phosphate concentrate II, and the phosphate concentrate I and the phosphate concentrate II are combined into a phosphate concentrate; The foam product II is introduced into the first scavenging operation for scavenging to obtain the in-tank product III and the foam product III. The in-tank product III returns to the previous step and enters the roughing operation together with the in-tank product I. The foam product III is introduced into the second scavenging operation for scavenging to obtain the in-tank product IV and the foam product IV. The in-tank product IV returns to the previous step and enters the first scavenging operation together with the foam product II. The foam product IV is the phosphate tailings.

[0026] In this embodiment, the P2O5 grade of phosphate concentrate I is controlled to be 29.48, the P2O5 grade of phosphate concentrate II is 30.91, the P2O5 grade of phosphate concentrate is 30.43%, the MgO content is 0.72%, the Al2O3 content is 2.54%, and the P2O5 recovery rate is 91.40%.

[0027] Example 3 A floatable separation process for improving the phosphorus recovery rate of fine-grained colloidal phosphate. The phosphate slurry described in this embodiment has a P2O5 grade of 26.0-28.0wt%, a MgO content of 0.8-1.5wt%, an Al2O3 content of 2.0-3.0wt%, a particle size of less than 0.025mm accounting for 70t, and a concentration of 22-25wt%. Figure 1 As shown, the technical scheme described in this embodiment is: introducing phosphate slurry into iso-floatable operation, adding fatty acid anion collector and amine cationic collector to the phosphate slurry simultaneously, wherein the mass ratio of the added fatty acid anion collector to the added amine cationic collector is 3.0 / 1.0, and the total amount of collector added per ton of dry pulp is 0.1 kg, and iso-floatable flotation is performed to obtain product I in the tank and foam product I, and the foam product I is phosphate concentrate I; The product I in the tank is introduced into a reverse flotation roughing operation, and a regulator and an amine cationic collector are added to the product I in the tank, wherein the amount of the regulator added per ton of dry basis of phosphate ore pulp is 6.0 kg, and the amount of the amine cationic collector added is 0.2 kg, and roughing is performed to obtain a tank product II and a foam product II, wherein the tank product II is phosphate concentrate II, and the phosphate concentrate I and the phosphate concentrate II are combined into a phosphate concentrate; The foam product II is introduced into the first scavenging operation for scavenging to obtain the in-tank product III and the foam product III. The in-tank product III returns to the previous step and enters the roughing operation together with the in-tank product I. The foam product III is introduced into the second scavenging operation for scavenging to obtain the in-tank product IV and the foam product IV. The in-tank product IV returns to the previous step and enters the first scavenging operation together with the foam product II. The foam product IV is the phosphate tailings.

[0028] In this embodiment, the P2O5 grade of phosphate concentrate I is controlled to be 28.84%, the P2O5 grade of phosphate concentrate II is 29.84%, the P2O5 grade of phosphate concentrate is 29.46%, the MgO content is 0.74%, the Al2O3 content is 2.76%, and the P2O5 recovery rate is 94.04%.

[0029] Example 4 A floatable separation process for improving the phosphorus recovery rate of fine-grained colloidal phosphate. The phosphate slurry described in this embodiment has a P2O5 grade of 24.0-26.0wt%, a MgO content of 0.8-1.5wt%, an Al2O3 content of 2.5-3.7wt%, a particle size of less than 0.025mm accounting for 55t%, and a concentration of 22-25wt%. Figure 1 As shown, the technical solution described in this embodiment is: introducing phosphate slurry into iso-floatable operation, adding fatty acid anion collector and amine cationic collector to the phosphate slurry simultaneously, wherein the mass ratio of the added fatty acid anion collector to the added amine cationic collector is 2.0, and the total amount of collector added per ton of dry pulp is 0.13 kg, and iso-floatable flotation is performed to obtain product I in the tank and foam product I, and the foam product I is phosphate concentrate I; The product I in the tank is introduced into a reverse flotation roughing operation, and a regulator and an amine cationic collector are added to the product I in the tank, wherein the amount of the regulator added per ton of dry basis of phosphate slurry is 4.0 kg, and the amount of the amine cationic collector added is 0.3 kg, and roughing is performed to obtain a tank product II and a foam product II, wherein the tank product II is phosphate concentrate II, and the phosphate concentrate I and the phosphate concentrate II are combined into a phosphate concentrate; The foam product II is introduced into the first scavenging operation for scavenging to obtain the in-tank product III and the foam product III. The in-tank product III returns to the previous step and enters the roughing operation together with the in-tank product I. The foam product III is introduced into the second scavenging operation for scavenging to obtain the in-tank product IV and the foam product IV. The in-tank product IV returns to the previous step and enters the first scavenging operation together with the foam product II. The foam product IV is the phosphate tailings.

[0030] In this embodiment, the P2O5 grade of phosphate concentrate I is controlled to be 29.84, the P2O5 grade of phosphate concentrate II is 31.23, the P2O5 grade of phosphate concentrate is 30.11%, the MgO content is 0.74%, the Al2O3 content is 2.61%, and the P2O5 recovery rate is 87.96%.

[0031] Example 5 A floatable separation process for improving the phosphorus recovery rate of fine-grained colloidal phosphate. The phosphate slurry described in this embodiment has a P2O5 grade of 22.0-24.0wt%, a MgO content of 0.8-1.5wt%, an Al2O3 content of 3.0-4.5wt%, a particle size of less than 0.025mm accounting for 55t%, and a concentration of 18-25wt%. Figure 1 As shown, the technical solution described in this embodiment is: introducing phosphate slurry into iso-floatable operation, adding fatty acid anion collector and amine cationic collector to the phosphate slurry simultaneously, wherein the mass ratio of the added fatty acid anion collector to the added amine cationic collector is 3.5 / 1.0, and the total amount of collector added per ton of dry pulp is 0.08kg; performing iso-floatable flotation to obtain product I in the tank and foam product I, wherein the foam product I is phosphate concentrate I; The product I in the tank is introduced into a reverse flotation roughing operation, and a regulator and an amine cationic collector are added to the product I in the tank, wherein the amount of the regulator added per ton of dry basis of phosphate ore pulp is 5.0 kg, and the amount of the amine cationic collector added is 0.35 kg, and roughing is performed to obtain a tank product II and a foam product II, wherein the tank product II is phosphate concentrate II, and the phosphate concentrate I and the phosphate concentrate II are combined into a phosphate concentrate; The foam product II is introduced into the first scavenging operation for scavenging to obtain the in-tank product III and the foam product III. The in-tank product III returns to the previous step and enters the roughing operation together with the in-tank product I. The foam product III is introduced into the second scavenging operation for scavenging to obtain the in-tank product IV and the foam product IV. The in-tank product IV returns to the previous step and enters the first scavenging operation together with the foam product II. The foam product IV is the phosphate tailings.

[0032] The phosphate concentrate obtained in this embodiment has a P2O5 grade of 29.71%, a MgO content of 0.78%, an Al2O3 content of 3.24%, and a P2O5 recovery rate of 85.3%.

[0033] In this embodiment, the P2O5 grade of phosphate concentrate I is controlled to be 27.14, the P2O5 grade of phosphate concentrate II is 28.76, the P2O5 grade of phosphate concentrate is 27.65%, the MgO content is 0.77%, the Al2O3 content is 3.05%, and the P2O5 recovery rate is 86.64%.

[0034] Example 6 A flotation separation process for improving the phosphorus recovery rate of fine-grained colloidal phosphate. The phosphate slurry described in this embodiment has a P2O5 grade of 26.0~28.0wt%, a MgO content of 0.8~1.5wt%, an Al2O3 content of 2.0~3.0wt%, a particle size of less than 0.025mm accounting for 63t, and a concentration of 18~23wt%. The technical solution described in this embodiment is: introducing the phosphate slurry into the reverse flotation roughing operation, first adding an adjusting agent to the phosphate slurry, and the amount of adjusting agent added per ton of dry phosphate slurry is 9.0kg; adding fatty acid anion collectors and amine cationic collectors to the phosphate slurry simultaneously, wherein the mass ratio of the added fatty acid anion collector to the amine cationic collector is 3.5 / 1.0, and the total amount of collector added per ton of dry slurry is 0.40kg; obtaining the in-tank product I and the foam product I, and the in-tank product I is a phosphate concentrate; The foam product I is introduced into the first scavenging operation for scavenging to obtain the in-tank product II and the foam product II. The in-tank product II returns to the previous step and enters the roughing operation together with the phosphate slurry. The foam product II is introduced into the second scavenging operation for scavenging to obtain the in-tank product III and the foam product III. The in-tank product III returns to the previous step and enters the first scavenging operation together with the foam product I. The foam product IV is the phosphate tailings.

[0035] In this embodiment, the P2O5 grade of the phosphate concentrate is controlled to be 28.53%, the MgO content is 0.78%, the Al2O3 content is 2.84%, and the P2O5 recovery rate is 56.81% during the flotation process.

[0036] Compared with the prior art, this specific implementation has the following positive effects: 1. The invention makes full use of the natural floatability of fine-grained collophanites, and floats the easily floatable minerals first. In the collophanites, the floatability of the minerals is in the order of dolomite minerals>colllophanites>siliceous minerals. After adding fatty acid collectors and amine collectors, the essence of the equal floatability separation process is to first float out the easily floatable dolomite minerals and some fine-grained collophanites, as well as the mud, suspended particles and some small amounts of ultra-fine-grained siliceous minerals mixed in the phosphate slurry after the early grinding. Since the phosphate slurry selected in the present invention has a MgO content of 0.8-1.5wt%, the equal floatation operation has a preselection effect in the present invention. First, the mud, suspended and ultrafine particles that affect the subsequent flotation are removed in advance to ensure the high separation of the subsequent flotation; second, a part of the fine-grained collophosphate ore is collected in advance. The P2O5 grade difference between the phosphate concentrate I and the phosphate concentrate II is less than 2%, and further less than 1%. Then, the phosphate concentrate I and the phosphate slurry II can be combined into a phosphate concentrate, and the P2O5 grade of the phosphate concentrate is guaranteed to be ≥27.5%, thereby improving the yield of the phosphate concentrate.

[0037] 2. The amount of flotation reagent is small. In order to ensure the iso-floatable pre-selection effect of the present invention, only a small amount of collector needs to be added to the iso-floatable process to float out some fine-grained collophanite, ultra-fine-grained siliceous minerals, and gangue minerals such as dolomite minerals, mud, and suspended particles. In the subsequent flotation operation, without the interference of these ultra-fine materials, adding an appropriate amount of selection reagent can obtain good process indicators, and the amount of reagent can be greatly reduced.

[0038] 3. The present invention adopts a mixture of sulfuric acid, phosphoric acid, iron-free aluminum sulfate and polyethylene glycol as a regulator, firstly to adjust the pH value of the slurry, and secondly to adjust the foam toughness, so as to improve the fluidity of the flotation foam, facilitate transportation, and avoid the problem of difficult foam accumulation and transportation difficulties.

[0039] 4. The addition method of the regulator and collector adopted in the present invention can achieve the simultaneous removal of magnesium and aluminum in phosphate minerals, avoiding the low flotation efficiency and complicated recycling of return water.

[0040] 5. The P2O5 grade of the phosphate concentrate obtained in the specific implementation manner of the present invention is ≥27.5%, and the phosphorus recovery rate is ≥85%.

[0041] Therefore, the present invention has the characteristics of stable process structure, high efficiency, high phosphorus recovery rate, small reagent consumption and low mineral processing cost.

Claims

1. A flotation separation process for improving the phosphorus recovery rate of fine-grained collophosphate, characterized in that: The steps include: (1) introducing phosphate slurry into iso-flotation operation, adding fatty acid anion collector and amine cationic collector to the phosphate slurry simultaneously, and performing iso-flotation flotation to obtain in-tank product I and foam product I, wherein the foam product I is phosphate concentrate I; (2) introducing the product I in the tank into a reverse flotation roughing operation, adding a regulator and an amine cationic collector to the product I in the tank, and performing roughing to obtain a product II in the tank and a foam product II. The product II in the tank is the phosphate concentrate II, and the phosphate concentrate I and the phosphate concentrate II are combined into a phosphate concentrate; (3) Foam product II is introduced into the first sweeping operation to obtain in-tank product III and foam product III. Foam product III is introduced into the second sweeping operation to obtain in-tank product IV and foam product IV. Foam product IV is phosphate tailings.

2. The isoflurane separation process for improving the phosphorus recovery rate of fine colloidal phosphate according to claim 1, characterized in that: The phosphate slurry has a P2O5 grade of 22.0-28.0wt%, a MgO content of 0.8-1.5wt%, an Al2O3 content of 2.0-4.5wt%, a particle size of less than 0.025mm accounting for 50-70wt%, and a concentration of 18-25wt%.

3. The isoflurane separation process for improving the phosphorus recovery rate of fine colloidal phosphate according to claim 1, characterized in that: The P2O5 grade of phosphate concentrate II is ≥28.5wt%, the MgO content is ≤0.8wt%, and the difference in P2O5 grade between phosphate concentrate I and phosphate concentrate II is less than 2%.

4. The isoflurane separation process for improving the phosphorus recovery rate of fine collophosphate according to claim 3, characterized in that: The P2O5 grade difference between the phosphate concentrate I and the phosphate concentrate II is less than 1%.

5. The isoflurane separation process for improving the phosphorus recovery rate of fine collophosphate according to claim 1, characterized in that: In the floatable operation, the mass ratio of fatty acid anionic collector to amine cationic collector is 2.0 / 1.0~3.5 / 1.0, and the total amount of collector added per ton of dry pulp is 0.05~0.15kg.

6. The isoflurane separation process for improving the phosphorus recovery rate of fine collophosphate according to claim 1, characterized in that: In the reverse flotation roughing operation, the amount of adjusting agent added per ton of phosphate slurry dry basis is 4.0~6.0kg, and the amount of amine cationic collector added is 0.2~0.35kg.

7. The isoflurane separation process for improving the phosphorus recovery rate of fine collophosphate according to claim 6, characterized in that: The adjusting agent is composed of the following components in mass percentage: 25-30% phosphoric acid, 13-17% sulfuric acid, 30-40% iron-free aluminum sulfate, and 6-20% polyethylene glycol, and the sum of the mass percentages of the components is 100%.

8. The isoflurane separation process for improving the phosphorus recovery rate of fine collophosphate according to claim 1, characterized in that: Product IV in the tank returns to the previous step and enters the first sweeping operation together with foam product II; product III in the tank returns to the previous step and enters the roughing operation together with product I in the tank.

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