A method for treating return water in a collophanite gravity-flotation combined separation production process

Abstract

This invention relates to a method for treating wastewater from the collophane heavy flotation and separation process. The steps are as follows: (1) Add treatment agent A to the wastewater generated during the collophane heavy flotation and separation process, and allow it to settle until complete precipitation; (2) Add treatment agent B to the supernatant from the previous step, and allow it to settle until complete precipitation; (3) Add treatment agent C to the supernatant from the previous step, and allow it to settle until complete precipitation; (4) Add treatment agent D to the supernatant from the previous step, and allow it to settle until complete precipitation. The treated supernatant can be reused in the collophane heavy flotation and separation process. Compared with the prior art, the raw materials selected in this invention are low-cost and widely available, the processing technology is simple, and the processing cost is low. It can simultaneously solve the problems of sticky flotation foam and reduced concentrate yield.

Description

Technical Field

[0001] This invention belongs to the field of collophane beneficiation technology, specifically relating to a method for treating the recycled water in the gravity flotation combined beneficiation process of collophane. Background Technology

[0002] my country has abundant phosphate resources, but most are low-quality collophane, requiring high grinding fineness and large flotation reagent consumption during beneficiation, resulting in large volumes of complex-composition flotation wastewater. Direct discharge of this wastewater would severely pollute the environment. Reusing flotation wastewater in the flotation process can effectively reduce water consumption, save costs, and protect the environment. However, during reuse, the concentration of flotation reagents and inorganic ions increases with the number of cycles. Direct reuse of such wastewater would severely affect the beneficiation indicators of the combined gravity flotation and flotation process, causing sticky froth in the magnesium removal stage, reducing concentrate yield, disrupting the stability of the entire production process, and leading to decreased production efficiency. Flotation wastewater reuse mainly affects flotation in the following ways: first, it affects the full dispersion of minerals; second, it changes the hydrophilicity or surface charge of minerals; third, some impurities in the wastewater react with reagents, increasing reagent consumption; and fourth, it affects the pH environment of the pulp, thereby altering the surface charge of minerals or the effectiveness of reagents. In particular, the residual organic reagents in the wastewater have an impact. During the flotation process, a large amount of mineral processing reagents are added. Some of them react with the mineral surface, while others react with some ions in the pulp, thus losing the proper function of the mineral processing reagents. After the wastewater is recycled multiple times, the residual organic collectors will cause the flotation foam to become sticky, which has a negative impact on mineral processing.

[0003] The wastewater generated from the gravity flotation process of phosphate rock contains a large amount of Ca. 2+ Mg 2+ The wastewater contains residual cationic and amine collectors. Direct reuse of this wastewater in flotation will cause the demagnesification foam to become sticky, reduce concentrate yield, and severely affect the stability of the combined gravity flotation process. Therefore, treating this wastewater before reuse can effectively improve flotation foam and mineral processing indicators, which is of great significance for ensuring the stable and continuous operation of the combined gravity flotation process.

[0004] Patent CN103819016A discloses a wastewater treatment method for a mixed production process of phosphate rock. This method uses multiple precipitants to remove inorganic ions from the wastewater through stepwise precipitation, and then reuses the treated wastewater in the positive flotation operation to achieve process parameters consistent with clean water. However, this method has no effect on removing flotation reagents from the water.

[0005] Patent CN115594353A discloses a method for treating wastewater from the double-reverse flotation of phosphate rock. This method introduces an eliminator into the wastewater to remove cationic collectors, and then uses activated carbon as an adsorbent to remove anionic collectors and eliminators from the wastewater. The resulting circulating water can be returned to the mineral processing process for reuse. This method is effective for removing flotation reagents from the wastewater, but it has no effect on removing calcium and magnesium ions. Summary of the Invention

[0006] The purpose of this invention is to solve the problem of viscous foam and decreased concentrate yield caused by wastewater reuse in the gravity flotation and separation of collophane. This invention proposes a wastewater treatment method for the gravity flotation and separation process of collophane. This method is low-cost, simple to operate, and enables stable and continuous operation of the gravity flotation and separation process of collophane.

[0007] The technical solution adopted by the present invention to solve the above-mentioned problems is as follows:

[0008] A method for treating recycled water in the gravity flotation and separation process of collophane ore, the specific steps of which are as follows:

[0009] (1) Add treatment agent A to the wastewater generated by the gravity flotation and separation process of collophane ore, and let it settle for more than 4 hours until the sedimentation is complete.

[0010] (2) Add treatment agent B to the supernatant in step (1) and let it settle for more than 2 hours until the sedimentation is complete;

[0011] (3) Add treatment agent C to the supernatant in step (2) and let it settle for more than 2 hours until the sedimentation is complete;

[0012] (4) Add treatment agent D to the supernatant from step (3) and allow it to settle for at least 2 hours until precipitation is complete. The treated supernatant can be reused in the gravity flotation and separation of phosphate rock.

[0013] In the above scheme, the treatment agent A mentioned in step (1) is lime slurry, and its mass fraction ranges from 20% to 30%.

[0014] In the above scheme, the mass ratio of the treatment agent A to the wastewater in step (1) is in the range of 3 to 5: 1000.

[0015] In the above scheme, the treatment agent B mentioned in step (2) is a composite agent composed of the following raw materials in parts by weight: 85-95 parts of montmorillonite, 4-6 parts of carboxymethyl cellulose, 2-4 parts of sodium dodecyl ether sulfate, and 1.5-2.5 parts of sodium dioctyl succinate sulfonate. The ratio of the mass of treatment agent B added to the mass of wastewater is 2-3.5:1000.

[0016] In the above scheme, the preparation method of the treatment agent B in step (2) is as follows:

[0017] Montmorillonite, carboxymethyl cellulose, and sodium dioctyl succinate sulfonate were mixed and then added to sodium dodecyl ether sulfate and mixed thoroughly to obtain treatment agent B. Montmorillonite adsorbs flotation reagents in water; carboxymethyl cellulose helps disperse montmorillonite in water, facilitating its adsorption of flotation reagents; sodium dodecyl ether sulfate is an anionic surfactant that helps precipitate flotation reagents in water; and sodium dioctyl succinate sulfonate is a surfactant that helps settle suspended solids and precipitates in water.

[0018] In the above scheme, the montmorillonite in the treatment agent B mentioned in step (2) includes either calcium-based montmorillonite or sodium-based montmorillonite.

[0019] In the above scheme, the treatment agent C mentioned in step (3) includes sodium carbonate, sodium bicarbonate, sodium phosphate, sodium dihydrogen phosphate, sodium monohydrogen phosphate and sodium silicate, and the ratio of the mass of treatment agent C added to the mass of wastewater is in the range of 2 to 4:1000.

[0020] In the above scheme, the treatment agent D in step (4) includes polyacrylamide, polyaluminum chloride, and polyferric chloride, with a mass fraction range of 0.1% to 1%, and the ratio of the mass of the flocculant solution added to the mass of wastewater ranges from 2 to 10:1000.

[0021] Compared with the prior art, the beneficial effects of this invention are:

[0022] This invention addresses the problem that the reuse of wastewater from the collophane ore gravitational flotation process causes sticky flotation foam in the magnesium removal stage and a decrease in the P2O5 yield of the concentrate. It uses a series of steps to treat the wastewater from the collophane ore gravitational flotation process, which is low-cost, easy to operate, and improves the water recycling rate. It can ensure smooth water circulation and continuous and stable operation of the collophane ore gravitational flotation process. Attached Figure Description

[0023] Figure 1 This is a flowchart of the roughing process in the magnesium removal stage of a phosphate rock gravity flotation combined beneficiation process.

[0024] Figure 2 For comparative examples and implementation examples, the flotation foam effect diagram is shown below: Figure 2 (a) Comparative Example 1; (b) Comparative Example 2; (c) Example 1; (d) Graph showing the effect of flotation foam in Example 2. Detailed Implementation

[0025] To better understand the present invention, the following description, in conjunction with embodiments and comparative examples, further illustrates the content of the present invention, but the present invention is not limited to the embodiments described below.

[0026] Unless otherwise specified, the following comparisons and implementation examples use commercially available chemical reagents or industrial products.

[0027] The flotation reagents used in the gravity flotation and separation process of phosphate rock in this invention contain amine groups. Therefore, the change in total nitrogen content in the wastewater represents the change in the flotation reagent content in the water. Simultaneously, the Ca content in both the wastewater and the treated wastewater is measured. 2+ Mg 2+ The content of.

[0028] Comparative Example 1

[0029] A small-scale demagnesification reverse flotation test was conducted using wastewater generated from the gravity flotation process of a phosphate mine in Yichang. The raw ore came from a phosphate mine in Yichang, with a P2O5 grade of 26.26%, MgO content of 2.14%, and a grinding fineness of -0.074mm mineral particles accounting for 84%. The wastewater was added to adjust the slurry to a concentration of 25%–30% for demagnesification reverse flotation. The specific flotation process is shown in [link to flotation procedure]. Figure 1 The concentrate yield was 69.95%, the P2O5 grade was 29.11%, and the MgO content was 0.76% (see Table 1). The demagnesification flotation showed significant foam accumulation and severe stickiness (see Table 1). Figure 2 .

[0030] Comparative Example 2

[0031] The wastewater described in this comparative example is the same as that in Comparative Example 1. The specific steps of wastewater treatment are as follows: (1) Add 5L of wastewater generated by the gravity flotation and separation process of phosphate rock to the wastewater purification tank, add 15mL of lime slurry with a mass fraction of 30% to the purification tank, mix well, and let it settle for 2 hours; (2) Add 15g of sodium carbonate to the clear liquid in step (1), mix well, and let it settle for 2 hours; (3) Add 10mL of polyacrylamide solution with a mass fraction of 0.5% to the clear liquid in step (2), and let it settle for 4 hours.

[0032] The treated supernatant was used for flotation, following the same flotation process as the comparative example. The concentrate yield was 74.57%, with a P2O5 grade of 29.51% and an MgO content of 0.81% (see Table 1). Compared to the comparative example, the demagnesium flotation concentrate yield increased by 4 percentage points after treatment using the method in Example 1. However, significant foam accumulation and stickiness issues remained in the demagnesium flotation process (see Table 1). Figure 2 .

[0033] Example 1

[0034] A method for treating wastewater from the gravity flotation and separation process of phosphate rock. The wastewater in this embodiment is the same as that in Comparative Example 1. The specific steps of wastewater treatment are as follows: (1) Add 5L of wastewater generated by the gravity flotation and separation process of phosphate rock to a wastewater purification tank, add 15mL of lime slurry with a mass fraction of 30% to the purification tank, mix well, and let it settle for 4 hours; (2) Add 15g of calcium montmorillonite, 0.8g of carboxymethyl cellulose, 0.6g of sodium dodecyl ether sulfate, and 0.25g of sodium dioctyl succinate to the clear liquid in step (1), mix well, and let it settle for 2 hours; (3) Add 15g of sodium carbonate to the clear liquid in step (2), mix well, and let it settle for 2 hours; (4) Add 5mL of polyacrylamide solution with a mass fraction of 0.5% to the clear liquid in step (3), and let it settle for 2 hours.

[0035] The treated supernatant was used for flotation, following the same flotation process as the comparative example, yielding a concentrate yield of 78.81%, a P2O5 grade of 29.67%, and an MgO content of 0.78% (see Table 1). Compared to the comparative example, after treatment using the method described in Example 1, the concentrate yield from the magnesium removal flotation increased by 8 percentage points, while the amount of foam in the magnesium removal flotation decreased, and the stickiness problem was resolved (see Table 1). Figure 2 .

[0036] Example 2

[0037] A method for treating wastewater from the gravity flotation and separation process of phosphate rock. The wastewater in this embodiment is the same as that in Comparative Example 1. The specific steps of wastewater treatment are as follows: (1) Add 5L of wastewater generated by the gravity flotation and separation process of phosphate rock to a wastewater purification tank, add 15mL of lime slurry with a mass fraction of 30% to the purification tank, mix well, and let it settle for 4 hours; (2) Add 10g of sodium montmorillonite, 0.5g of carboxymethyl cellulose, 0.3g of sodium dodecyl ether sulfate, and 0.2g of sodium dioctyl succinate to the clear liquid in step (1), mix well, and let it settle for 2 hours; (3) Add 10g of sodium carbonate to the clear liquid in step (2), mix well, and let it settle for 2 hours; (4) Add 5mL of polyacrylamide solution with a mass fraction of 0.5% to the clear liquid in step (3), and let it settle for 2 hours.

[0038] The treated supernatant was used for flotation, following the same flotation process as the comparative example, yielding a concentrate yield of 80.09%, a P2O5 grade of 29.45%, and an MgO content of 0.69% (see Table 1). Compared to the comparative example, after treatment using the method described in Example 2, the concentrate yield from the magnesium removal flotation increased by 10 percentage points, while the amount of foam in the magnesium removal flotation decreased, and the stickiness problem was resolved (see Table 2). Figure 2 .

[0039] Example 3

[0040] Based on Example 2, the composition of the treatment agent B added in step (2) was changed.

[0041] Example 3-1: The treatment agent B added in step (2) was replaced with 10g sodium montmorillonite, 0.5g carboxymethyl cellulose, and 0.3g sodium dodecyl ether sulfate. All other steps were the same as in Example 2. The treated supernatant was used for flotation, and the flotation process was the same as in Comparative Example 1, yielding a concentrate yield of 78.45%, a concentrate P2O5 grade of 29.59%, and a MgO content of 0.71% (see Table 1). Compared with Example 2, after the wastewater was treated by the method in Example 3-1, the concentrate yield of the magnesium removal flotation decreased by 1.5 percentage points, and the amount of froth in the magnesium removal flotation was slightly reduced, but the stickiness problem still existed.

[0042] Example 3-2: The treatment agent B added in step (2) was replaced with 10g sodium montmorillonite, 0.5g carboxymethyl cellulose, and 0.2g sodium dioctyl succinate sulfonate. All other steps were the same as in Example 2. The treated supernatant was used for flotation, and the flotation process was the same as in Comparative Example 1, yielding a concentrate yield of 78.89%, a concentrate P2O5 grade of 29.45%, and an MgO content of 0.68% (see Table 1). Compared with Example 2, after the wastewater was treated by the method in Example 3-2, the concentrate yield of the demagnesification flotation decreased by 1.2 percentage points, and the amount of froth in the demagnesification flotation was slightly reduced, but the stickiness problem still existed.

[0043] Example 3-3: The treatment agent B added in step (2) was replaced with 10g sodium montmorillonite, 0.3g sodium dodecyl ether sulfate, and 0.2g sodium dioctyl succinate sulfonate. All other steps were the same as in Example 2. The treated supernatant was used for flotation, and the flotation process was the same as in Comparative Example 1, yielding a concentrate yield of 77.78%, a concentrate P2O5 grade of 29.89%, and a MgO content of 0.83% (see Table 1). Compared with Example 2, after treatment with the method in Example 3-3, the concentrate yield of the demagnesium flotation decreased by 2.2 percentage points, and the amount of froth in the demagnesium flotation was slightly reduced, but the stickiness problem still existed.

[0044] Examples 3-4: The treatment agent B added in step (2) was replaced with 10g of sodium montmorillonite and 0.5g of carboxymethyl cellulose. All other steps were the same as in Example 2. The treated supernatant was used for flotation, and the flotation process was the same as in Comparative Example 1, yielding a concentrate yield of 78.12%, a concentrate P2O5 grade of 29.71%, and an MgO content of 0.77% (see Table 1). Compared with Example 2, after the wastewater was treated by the method in Examples 3-4, the concentrate yield of the magnesium removal flotation decreased by 2 percentage points, and the amount of froth in the magnesium removal flotation was slightly reduced, but the stickiness problem still existed.

[0045] Examples 3-5: The treatment agent B added in step (2) was replaced with 10g of sodium montmorillonite and 0.2g of sodium dioctyl succinate sulfonate. All other steps were the same as in Example 2. The treated supernatant was used for flotation, and the flotation process was the same as the comparative example, yielding a concentrate yield of 77.56%, a concentrate P2O5 grade of 29.47%, and an MgO content of 0.85% (see Table 1). Compared with Example 2, after the wastewater was treated by the method in Examples 3-5, the concentrate yield of the demagnesium flotation decreased by 2.5 percentage points, and the amount of froth in the demagnesium flotation was slightly reduced, but the stickiness problem still existed.

[0046] Examples 3-6: The treatment agent B added in step (2) was replaced with 10g of sodium montmorillonite and 0.3g of sodium dodecyl ether sulfate. All other steps were the same as in Example 2. The treated supernatant was used for flotation, and the flotation process was the same as the comparative example, yielding a concentrate yield of 78.03%, a concentrate P2O5 grade of 29.84%, and a MgO content of 0.89% (see Table 1). Compared with Example 2, after the wastewater was treated by the method in Examples 3-6, the concentrate yield of the demagnesium flotation decreased by 2 percentage points, and the amount of froth in the demagnesium flotation was slightly reduced, but the stickiness problem still existed.

[0047] Table 1. Return water index and magnesium removal test index

[0048]

[0049]

[0050] As shown in Table 1, the total nitrogen content of the wastewater decreased after treatment using the methods described in the two embodiments, indicating that the flotation reagent content was reduced after treatment. Simultaneously, the Ca content decreased. 2+ Mg 2+ The content of magnesium decreased significantly. Compared with using untreated wastewater for magnesium removal flotation, the concentrate yield increased significantly when using treated wastewater for magnesium removal flotation.

[0051] Compared with Comparative Example 1 and Comparative Example 2, Examples 1 and 2 produced less flotation foam and significantly increased the P2O5 grade of the concentrate.

[0052] In Comparative Example 2, the wastewater treatment method omitted the addition of treatment agent B and carried out magnesium removal flotation. However, the flotation foam still had a lot of foam accumulation and the problem of stickiness still existed.

[0053] Comparing Example 1 and Example 2, treatment agent B uses sodium-based montmorillonite as the main component. Compared with calcium-based montmorillonite, the dosage of the agent is lower, and the concentrate yield is higher after the wastewater is treated.

[0054] Comparing Example 3 with Example 2, the concentrate yield decreased significantly, the amount of demagnesium foam increased, and the problem of sticky foam still existed, indicating that the components in treatment agent B play an important role in the treatment effect of the recycled water.

[0055] Example 4

[0056] Based on Example 1, sodium carbonate in step (3) is replaced with sodium chloride, and all other steps are the same as in Example 2.

[0057] The treated supernatant was used for flotation, following the same flotation process as Comparative Example 1, yielding a concentrate yield of 76.92%, a P2O5 grade of 29.21%, and an MgO content of 0.87% (see Table 1). Compared to Example 2, after treatment using the method in Example 4, the calcium and magnesium ion concentrations of the wastewater increased significantly, and the concentrate yield from the magnesium removal flotation decreased by 3 percentage points. Simultaneously, the amount of foam in the magnesium removal flotation decreased, and the stickiness problem was resolved. This indicates that sodium carbonate plays a crucial role in the treatment of the recycled water; adding sodium carbonate to treat the recycled water can significantly increase the concentrate yield.

[0058] In summary, the wastewater treatment method proposed in this invention for the gravity flotation and separation process of phosphate rock introduces multiple treatment agents into the wastewater to remove calcium and magnesium ions and residual flotation reagents without causing secondary pollution. The treated wastewater is then reused in the gravity flotation and separation process, simultaneously addressing the problems of sticky flotation foam and decreased P2O5 concentrate yield in the magnesium removal stage.

[0059] The method provided by this invention has low reagent cost, simple process operation, small footprint, improves the recycling rate of recycled water, and realizes smooth water circulation and continuous and stable operation in the phosphate rock gravity flotation and separation process.

[0060] The embodiments described above are merely preferred embodiments of the present invention, and not all embodiments. It should be noted that all modifications, improvements, or equivalent substitutions made by those skilled in the art based on the embodiments of the present invention without departing from the core concept of the present invention are within the protection scope of the present invention.

Claims

1. A method for treating recycled water in a gravity flotation and beneficiation process for phosphate rock, characterized in that, The specific process steps are as follows: 1) Add treatment agent A to the wastewater generated by the gravity flotation and separation process of collophane ore, and let it settle for more than 4 hours until the sedimentation is complete. Treatment agent A is lime slurry. 2) Add treatment agent B to the supernatant in step 1) and let it settle for more than 2 hours until the precipitation is complete. Treatment agent B is a compound agent composed of the following raw materials in parts by weight: 85-95 parts montmorillonite, 4-6 parts carboxymethyl cellulose, 2-4 parts sodium dodecyl ether sulfate, and 1.5-2.5 parts sodium dioctyl succinate sulfonate. 3) Add treatment agent C to the supernatant in step 2) and let it settle for more than 2 hours until the precipitation is complete. Treatment agent C is sodium carbonate. 4) Add treatment agent D to the supernatant in step 3), D includes polyacrylamide, polyaluminum chloride and polyferric chloride, and let it settle for more than 2 hours until the sedimentation is complete. The treated supernatant can be reused in the gravity flotation and beneficiation of phosphate rock.

2. The water treatment method for the gravity flotation and beneficiation process of phosphate rock according to claim 1, characterized in that, The mass fraction of treatment agent A mentioned in step 1) is in the range of 20% to 30%.

3. The method for treating recycled water in the gravity flotation and beneficiation process of phosphate rock according to claim 1, characterized in that, The mass ratio of treatment agent A to wastewater in step 1) is (3~5):1000.

4. The method for treating recycled water in the gravity flotation and beneficiation process of phosphate rock according to claim 1, characterized in that, The preparation method of the treatment agent B is as follows: Montmorillonite, carboxymethyl cellulose, and sodium dioctyl succinate were mixed and then sodium dodecyl ether sulfate was added and mixed evenly to obtain treatment agent B.

5. The water treatment method for the gravity flotation and beneficiation process of phosphate rock according to claim 4, characterized in that, The montmorillonite includes either calcium-based montmorillonite or sodium-based montmorillonite.

6. The method for treating recycled water in the gravity flotation and beneficiation process of phosphate rock according to claim 1, characterized in that, In step 2), the ratio of the mass of treatment agent B added to the mass of wastewater is in the range of (2~3.5):1000.

7. The method for treating recycled water in the gravity flotation and beneficiation process of phosphate rock according to claim 1, characterized in that, In step 3), the ratio of the mass of the treatment agent C added to the mass of the wastewater is in the range of (2~4):1000.

8. The method for treating recycled water in the gravity flotation and beneficiation process of phosphate rock according to claim 1, characterized in that, The mass fraction of the treatment agent D mentioned in step 4) is in the range of 0.1% to 1%.

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