A method for recovering valuable elements by side and bottom residue synergistic flotation

Abstract

The present application belongs to the technical field of valuable metal recovery, and particularly relates to a method for cooperatively floating and recovering valuable elements from side slag and bottom slag, comprising the following steps: S1, mixing copper smelting side slag with copper smelting bottom slag to obtain mixed slag material; S2, performing one-stage grinding on the mixed slag material to obtain first ore slurry; S3, performing first floating operation on the first ore slurry to obtain first concentrate and first tailings; S4, performing two-stage grinding on the first tailings to obtain second ore slurry; S5, performing second floating operation on the second ore slurry to obtain second concentrate and final tailings; and S6, combining the first concentrate and the second concentrate to perform cleaning operation to obtain final copper concentrate. The present application mixes high-silicon and easy-mudification side slag with high-density and easy-settlement bottom slag, significantly reduces the overall viscosity and density of the mixed ore slurry, improves the rheological properties, and creates an excellent floating physical environment.

Description

Technical Field

[0001] This invention relates to a method for the synergistic flotation recovery of valuable elements from side ash and bottom ash, belonging to the field of valuable metal recovery technology. Background Technology

[0002] In the pyrometallurgical process of copper, core smelting equipment (such as side-blown furnaces and bottom-blown oxygen-enriched furnaces) inevitably generates a large amount of smelting slag with varying compositions and physicochemical properties while efficiently producing the intermediate product, matte. This slag is a solid product formed from a mixture of molten oxides after slow cooling or water quenching. Depending on the type of furnace, the smelting slag produced by side-blown furnaces is commonly referred to as "side slag" in the industry, while that produced by bottom-blown furnaces is called "bottom slag." Although discharged as waste, its chemical composition still contains valuable metals such as copper, gold, and silver of considerable grade, making it a secondary resource with significant economic recovery value.

[0003] Side slag and bottom slag differ significantly in chemical composition, mineral composition, and physical properties. Side slag typically exhibits high silica and low iron content, with a relatively low Fe / SiO2 ratio. After slow cooling, its main phases are glassy silicates and dispersed copper matte particles or metallic copper beads. Due to the high oxygen potential of the melt, copper mainly exists in oxide form or is dissolved in the silicate glass phase, with fewer independent copper sulfide minerals. The high SiO2 content results in high slag viscosity and poor fluidity. The cooled side slag has a brittle and hard structure, making it extremely prone to over-grinding during grinding, producing a large amount of fine-grained sludge with a very large specific surface area and surface activity.

[0004] Bottom slag is typically characterized by high iron and low silicon content, a high Fe / SiO2 ratio, and is dense and hard, but relatively tough. It has extremely high oxygen potential and extremely low sulfur content, with the main crystalline phase being a framework structure composed of fir olivine and magnetite. The occurrence of valuable metals, especially copper, is extremely complex: a small amount of very fine matte or metallic copper particles are encased within the fir olivine crystals or between grain boundaries, while a significant portion of copper exists in ionic form dissolved in the fir olivine lattice or within the silicate glass phase.

[0005] Currently, separate flotation of side slag suffers from problems such as high pulp viscosity, severe interference from fine slime, and high reagent consumption; while separate treatment of bottom slag faces bottlenecks such as high grinding energy consumption and complex copper occurrence states that hinder recovery rates. Simply mixing the two and returning them directly to the smelting system, while processing waste slag, increases the heat load and energy consumption of the smelting process. Therefore, how to achieve economical and efficient integrated recovery of these two slag materials with significantly different characteristics is a key issue that the industry urgently needs to address. Summary of the Invention

[0006] This invention addresses the shortcomings of existing technologies, such as poor pulp properties, high grinding energy consumption, low recovery rate of valuable metals, and poor economic benefits, when flotating side slag and bottom slag separately. It provides a method for the co-flotation of side slag and bottom slag to recover valuable elements.

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

[0008] A method for recovering valuable elements by co-flotation of side ash and bottom ash includes the following steps:

[0009] S1. Mix the copper smelting side slag with the copper smelting bottom slag to obtain a mixed slag material;

[0010] S2. The mixed slag is subjected to a first-stage grinding process to obtain the first slurry;

[0011] S3. Perform a first flotation operation on the first slurry, adding a pH adjuster, a first activator, a first collector, and a first frother to obtain a first concentrate and a first tailings;

[0012] S4. The first tailings are subjected to two-stage grinding to obtain the second slurry;

[0013] S5. Perform a second flotation operation on the second slurry, adding a second activator, a second collector and a second frother to obtain a second concentrate and final tailings.

[0014] S6. Combine the first concentrate and the second concentrate and perform a fine-refining process to obtain the final copper concentrate.

[0015] Based on the above technical solution, the present invention can also be improved as follows:

[0016] Furthermore, in step S1, the mixing ratio of the copper smelting side slag and the copper smelting bottom slag is controlled by the mass ratio of SiO2 to Fe in the mixed slag material to be 0.65 to 0.75.

[0017] This invention fundamentally optimizes the rheological properties of flotation pulp by mixing side slag and bottom slag with significantly different SiO2 / Fe ratios in a ratio of 0.65–0.75. Pulp viscosity is affected by the particle size distribution, density, and shape of the solid particles. Side slag easily becomes muddy, producing a large amount of fine mud, leading to excessive pulp viscosity; bottom slag has a high density and coarse particles, easily causing the pulp to settle too quickly. After mixing, when the SiO2 / Fe ratio is between 0.65 and 0.75, the ratio of fine mud to coarse particles (iron minerals) reaches an optimal synergistic state. The fine particles moderately fill the gaps between coarse particles, reducing the degree of free water encapsulation between particles, increasing pulp density, decreasing apparent viscosity, and achieving a suitable overall density. This makes the pulp neither prone to settling nor excessively viscous, exhibiting an ideal hydrodynamic state, which is conducive to uniform bubble dispersion and stable suspension of mineral particles, creating prerequisites for efficient flotation. If the SiO2 / Fe ratio is too high (>0.75), there will be an excess of fine mud, resulting in excessive slurry viscosity, decreased probability of bubble-particle collision, and poor selectivity. If the SiO2 / Fe ratio is too low (<0.65), coarse iron minerals will dominate, leading to excessively rapid slurry settling, short bubble residence time, and reduced recovery rate. At this ratio, the chemical properties and mineral composition of the mixed slag achieve optimal synergy, suppressing the mudification tendency of high-silica side slag and the high viscosity problem of the slurry, avoiding excessive reagent consumption caused by high-iron bottom slag, and optimizing the floatability of gangue minerals.

[0018] Furthermore, in step S1, the copper smelting side slag comprises the following components by mass percentage: Cu 0.5%–1.0%, Fe 35%–38%, SiO2 30%–34%, and MgO 1.5%–2.5%.

[0019] Furthermore, in step S1, the copper smelting bottom slag includes the following components by mass percentage: Cu 3%–4%, Fe 40%–44%, SiO2 20%–24%, and MgO ≤0.01%.

[0020] Furthermore, in step S2, after the first grinding stage, the grinding fineness is controlled so that the proportion of particles with a particle size of -0.074 mm is 50% to 70%. At this fineness, brittle side slag particles are preferentially crushed, and the resulting sharp edges effectively grind and erode the tough bottom slag particles, thus initially promoting the dissociation of valuable metals in the bottom slag with lower energy consumption, achieving "grinding hard with soft materials".

[0021] Further, in step S3, the conditions for the first flotation operation include: a pulp concentration of 33%–37% and a pH value of 9–10; the pH adjuster is lime; the activator is sodium sulfide, with an addition amount of 300–500 g / t of mixed residue; the first collector is a mixture of isobutyl xanthate and pentyl xanthate, wherein the mass ratio of isobutyl xanthate to pentyl xanthate is 1:1–2, and the total addition amount is 200–300 g / t of mixed residue; the first frother is pine oil, with an addition amount of 20–60 g / t of mixed residue.

[0022] Furthermore, in step S4, after the two-stage grinding, the grinding fineness is controlled so that the proportion of particles with a diameter of -0.074 mm is 85% to 90%. This fineness further dissociates the fine-grained valuable metals trapped in the bottom ash olivine. At the same time, due to the "dilution" effect of the side ash, the viscosity of the mixed slurry is suitable, avoiding the extremely high energy consumption and slurry deterioration problems caused by ultrafine grinding when treating the bottom ash separately.

[0023] Further, in step S5, the conditions for the second flotation operation include: a pulp concentration of 30%–35% and a pH value of 9–10; the second activator is sodium sulfide, with an addition amount of 50–100 g / t of mixed residue; the second collector is a mixture of isobutyl xanthate and pentyl xanthate, wherein the mass ratio of isobutyl xanthate to pentyl xanthate is 1:1–2, and the total addition amount is 50–100 g / t of mixed residue; the second frother is pine oil, with an addition amount of 5–20 g / t of mixed residue.

[0024] Furthermore, step S5 also includes a step of magnetic separation of the middlings or tailings produced by the second flotation operation to obtain magnetically separated tailings and iron concentrate, wherein the magnetically separated tailings are the final tailings.

[0025] Furthermore, in step S6, the refined tailings generated by the refining operation are returned to the grinding process in step S2 to form a closed loop and improve the metal recovery rate.

[0026] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0027] This invention mixes high-silica, easily mud-forming side slag with high-density, easily settling bottom slag, improving the particle size distribution of the mixed slurry, significantly reducing the overall viscosity and density of the mixed slurry, improving rheological properties, making bubble dispersion more uniform, and mineral particle suspension more stable, thus creating a superior flotation physical environment.

[0028] This invention utilizes the brittle and fragile nature of the side slag to preferentially crush it in a single grinding stage. The resulting sharp particles act as "natural grinding media" to effectively grind the tough bottom slag, achieving the effect of "grinding hard with soft materials." This promotes the dissociation of valuable metals in the bottom slag at a relatively coarse grinding fineness, significantly reducing the total energy consumption of grinding.

[0029] This invention achieves, for the first time, the active optimization of the rheological properties of the mixed slurry of side slag and bottom slag by adjusting the extreme silicon-iron ratio to a suitable intermediate range through the mixing of slag materials (controlling the mass ratio of SiO2 to Fe in the mixed slag materials to 0.65-0.75). Under this ratio, the floatability of gangue minerals (such as fir olivine and silicate glass phase) is suppressed, while the unnecessary adsorption of reagents caused by excessive iron minerals is reduced, thereby improving the selectivity and reagent efficiency of the flotation process.

[0030] The low-grade side slag of this invention has increased processing value by incorporating high-grade bottom slag; the high-processing-cost bottom slag has reduced grinding and flotation difficulty and reagent consumption due to the physicochemical conditioning effect of the side slag. The complementary advantages and synergistic effect of the two result in a significantly higher overall recovery rate of copper, gold, and silver than either of them alone or in simple mixed processing, achieving optimal overall technical and economic indicators. Attached Figure Description

[0031] Figure 1 This is a schematic diagram of the process flow of the present invention. Detailed Implementation

[0032] The principles and features of the present invention are described below with reference to the accompanying drawings. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0033] like Figure 1 As shown, the present invention provides a method for recovering valuable elements by co-flotation of side slag and bottom slag, which mainly includes the following steps: mixing and batching, primary grinding, first flotation operation (roughing), secondary grinding, second flotation operation (mid-stage), magnetic separation and cleaning.

[0034] Example 1

[0035] The slow-cooling side slag and slow-cooling bottom slag produced by the smelter are used as raw materials.

[0036] The main components (mass percentage) of the side slag are: Cu 1.0%, Fe 37.89%, SiO2 33.95%, MgO 2.38%, Au 0.97g / t, Ag 24.93g / t.

[0037] The main components of the bottom slag are: Cu 3.97%, Fe 43.86%, SiO2 23.89%, MgO 0.01%, Au 9.78g / t, Ag 146.59g / t.

[0038] The ingredients were prepared and mixed according to a controlled SiO2 / Fe mass ratio of 0.71 (the mass ratio of side slag to bottom slag was approximately 1:1).

[0039] After the mixed slag is crushed by a jaw crusher, it is fed into a ball mill for grinding. The grinding fineness is controlled to be -0.074mm, accounting for 60%, to obtain a first slurry with a concentration of about 35%.

[0040] The first slurry is pumped into the roughing flotation machine. First, lime is added to adjust the slurry pH to 9.5, then sodium sulfide (400 g / t of mixed material), collector (isobutyl xanthate and pentyl xanthate mixed at a 1:1.5 ratio, total addition 250 g / t), and pine oil (40 g / t) are added sequentially. Roughing flotation is performed; the frothy product scraped off is the first concentrate, and the product remaining in the tank is the first tailings.

[0041] The first tailings were pumped into a second-stage ball mill for regrinding, and the grinding fineness was controlled to be -0.074mm, accounting for 88%, to obtain a second slurry with a concentration of about 33%.

[0042] The regrinded second pulp is fed into a mid-stage flotation machine, with the addition of sodium sulfide (80 g / t), collector (isobutyl xanthate and pentyl xanthate mixed at a ratio of 1:1.5, total addition 80 g / t), and pine oil (12 g / t). Mid-stage flotation is then performed, and the frothy product is scraped off as the second concentrate.

[0043] The product (iron raw material) in the flotation tank is mixed with water to control the slurry concentration to below 25%, and then pumped into a magnetic separator. The magnetic concentrate is iron concentrate powder, and the magnetic tailings are the final tailings.

[0044] The first and second concentrates were combined and subjected to a fine-refining process. Sodium sulfide (50 g / t), collector (isobutyl xanthate and pentyl xanthate mixed at a ratio of 1:1.5, with a total addition of 40 g / t), and pine oil (5 g / t) were added to obtain the final copper concentrate. The refined tailings were returned to a primary ball mill.

[0045] The results of the valuable metal grades and recovery rates of the raw material slag, copper concentrate, and iron ore in this embodiment are shown in Table 1.

[0046] Table 1. Grade and recovery rate of valuable metals in Example 1

[0047]

[0048] Example 2

[0049] The slow-cooling side slag and slow-cooling bottom slag produced by the smelter are used as raw materials.

[0050] The main components (mass percentage) of the side slag are: Cu 1.0%, Fe 37.89%, SiO2 33.95%, MgO 2.38%, Au 0.97g / t, Ag 24.93g / t.

[0051] The main components of the bottom slag are: Cu 3.02%, Fe 40.25%, SiO2 20.26%, MgO 0.01%, Au 5.21g / t, Ag 10 1.24g / t.

[0052] The ingredients were prepared and mixed according to a controlled SiO2 / Fe mass ratio of 0.75 (the mass ratio of side slag to bottom slag was approximately 13:7).

[0053] After the mixed slag is crushed by a jaw crusher, it is fed into a ball mill for grinding. The grinding fineness is controlled to be -0.074mm, accounting for 50%, to obtain a first slurry with a concentration of about 33%.

[0054] The first slurry is pumped into the roughing flotation machine. First, lime is added to adjust the slurry pH to 9.0, then sodium sulfide (300 g / t of mixed material), collector (isobutyl xanthate and pentyl xanthate mixed in a 1:1 ratio, total addition 200 g / t), and pine oil (20 g / t) are added sequentially. Roughing flotation is performed; the frothy product is the first concentrate, and the product remaining in the tank is the first tailings.

[0055] The first tailings were pumped into a second-stage ball mill for regrinding, and the grinding fineness was controlled to be -0.074mm, accounting for 85%, to obtain a second slurry with a concentration of about 30%.

[0056] The regrinded second pulp is fed into a mid-stage flotation machine, with the addition of sodium sulfide (50 g / t), collector (isobutyl xanthate and pentyl xanthate mixed in a 1:1 ratio, total addition 50 g / t), and pine oil (5 g / t). Mid-stage flotation is then performed, and the frothy product is the second concentrate.

[0057] The product (iron raw material) in the flotation tank is mixed with water to control the slurry concentration to below 25%, and then pumped into a magnetic separator. The magnetic concentrate is iron concentrate powder, and the magnetic tailings are the final tailings.

[0058] The first and second concentrates were combined and subjected to a fine-refining process. Sodium sulfide (50 g / t), collector (isobutyl xanthate and pentyl xanthate mixed at a ratio of 1:1.5, with a total addition of 40 g / t), and pine oil (5 g / t) were added to obtain the final copper concentrate. The refined tailings were returned to a primary ball mill.

[0059] The results of the valuable metal grades and recovery rates of the raw material slag, copper concentrate, and iron ore in this embodiment are shown in Table 2.

[0060] Table 2. Grade and recovery rate of valuable metals in Example 2

[0061]

[0062] Example 3

[0063] The slow-cooling side slag and slow-cooling bottom slag produced by the smelter are used as raw materials.

[0064] The main components (mass percentage) of the side slag are: Cu 0.51%, Fe 35.26%, SiO2 30.14%, MgO 1.68%, Au 0.53g / t, Ag 10.68g / t.

[0065] The main components of the bottom slag are: Cu 3.97%, Fe 43.86%, SiO2 23.89%, MgO 0.01%, Au 9.78g / t, Ag 146.59g / t.

[0066] The ingredients were prepared and mixed according to a controlled SiO2 / Fe mass ratio of 0.65 (the mass ratio of side slag to bottom slag was approximately 2:3).

[0067] After the mixed slag is crushed by a jaw crusher, it is fed into a ball mill for grinding. The grinding fineness is controlled to be -0.074mm, accounting for 70%, to obtain a first slurry with a concentration of about 37%.

[0068] The first slurry is pumped into the roughing flotation machine. First, lime is added to adjust the slurry pH to 10. Then, sodium sulfide (500 g / t of mixed material), collector (isobutyl xanthate and pentyl xanthate mixed in a 1:2 ratio, total addition 300 g / t), and pine oil (60 g / t) are added sequentially. Roughing flotation is performed; the frothy product scraped off is the first concentrate, and the product remaining in the tank is the first tailings.

[0069] The first tailings were pumped into a second-stage ball mill for regrinding, and the grinding fineness was controlled to be -0.074 mm, accounting for 90%, to obtain a second slurry with a concentration of about 35%.

[0070] The regrinded second pulp is fed into a mid-stage flotation machine, with the addition of sodium sulfide (100 g / t), collector (isobutyl xanthate and pentyl xanthate mixed in a 1:2 ratio, total addition 100 g / t), and pine oil (20 g / t). Mid-stage flotation is then performed, and the frothy product is scraped off as the second concentrate.

[0071] The product (iron raw material) in the flotation tank is mixed with water to control the slurry concentration to below 25%, and then pumped into a magnetic separator. The magnetic concentrate is iron concentrate powder, and the magnetic tailings are the final tailings.

[0072] The first and second concentrates were combined and subjected to a fine-refining process. Sodium sulfide (50 g / t), collector (isobutyl xanthate and pentyl xanthate mixed at a ratio of 1:1.5, with a total addition of 40 g / t), and pine oil (5 g / t) were added to obtain the final copper concentrate. The refined tailings were returned to a primary ball mill.

[0073] The results of the valuable metal grades and recovery rates of the raw material slag, copper concentrate, and iron ore in this embodiment are shown in Table 3.

[0074] Table 3. Grade and recovery rate of valuable metals in Example 3

[0075]

[0076] Comparative Example 1

[0077] Side slag from the same source as in Example 1 was used, without adding bottom slag. The same grinding and flotation process as in Example 1 was employed. Due to excessively high pulp viscosity and severe mudding, the flotation froth was sticky, resulting in extremely poor selectivity.

[0078] The results of the valuable metal grades and recovery rates of the raw material slag, copper concentrate, and iron ore in this comparative example are shown in Table 4.

[0079] Table 4. Grade and recovery rate of valuable metals in Comparative Example 1

[0080]

[0081] Comparative Example 2

[0082] Bottom slag from the same source as in Example 1 was used, without adding side slag. The same grinding and flotation process as in Example 1 was adopted. During the flotation process, the pulp settling speed was fast, and bubble co-occurrence was severe, resulting in insurmountable bottlenecks in the overall recovery rate and the original value of iron.

[0083] The results of the valuable metal grades and recovery rates of the raw material slag, copper concentrate, and iron ore in this comparative example are shown in Table 5.

[0084] Table 5. Grade and recovery rate of valuable metals in Comparative Example 2

[0085]

[0086] Comparative Example 3

[0087] The operating steps are the same as in Example 1, except that the mixing ratio of side slag and bottom slag is changed so that the final SiO2 / Fe mass ratio of the mixed slag is 0.80. At this point, the mixed slurry exhibits a significant viscosity, severe bubble co-occurrence, and poor flotation selectivity.

[0088] The results of the valuable metal grades and recovery rates of the raw material slag, copper concentrate, and iron ore in this comparative example are shown in Table 6.

[0089] Table 6. Grade and recovery rate of valuable metals in Comparative Example 3

[0090]

[0091] Comparative Example 4

[0092] The operating steps are the same as in Example 1, except that the mixing ratio of side slag and bottom slag is changed so that the SiO2 / Fe mass ratio of the final mixed slag is 0.58. At this time, the slurry settling speed is significantly accelerated, the slurry in the flotation cell settles quickly, and the foam layer becomes thinner and unstable.

[0093] The results of the valuable metal grades and recovery rates of the raw material slag, copper concentrate, and iron ore in this comparative example are shown in Table 7.

[0094] Table 7. Valuable metal grades and recovery rates in Comparative Example 4

[0095]

[0096] Effect Comparison

[0097] The recovery rates of valuable metals in Examples 1-3 were compared with those in Comparative Examples 1-4, and the results are shown in Table 8 below:

[0098] Table 8 Comparison of valuable metal recovery rate data between Examples 1-3 and Comparative Examples 1-4

[0099]

[0100] As shown in the table above, when the SiO2 / Fe ratio is controlled within the range of 0.65 to 0.75 (Examples 1-3), the recovery rates of gold, silver, and copper are all consistently above 95%, which is superior to Comparative Examples 1-4, and the slurry rheology is good. Once the SiO2 / Fe ratio exceeds this range (Comparative Examples 3 and 4), the recovery rates all show a significant decrease, and the slurry rheology deteriorates. The recovery rate of bottom ash treated alone (Comparative Example 2) is better than that of Comparative Example 3 (mixed ash, SiO2 / Fe mass ratio of 0.8), but the grade of valuable metals in its iron ore is much higher than that in Comparative Example 3. Since iron ore is the product of the intermediate beneficiation process and is used for magnetic separation, the grade of valuable metals in it is crucial, and the lower the grade, the better. Although the recovery rate data of Comparative Example 2 treating bottom ash alone is better than that of Comparative Example 3, the grade of valuable metals in the iron ore is not effectively controlled, which does not meet the process requirements for low-grade iron ore, thus affecting the overall efficiency of valuable metal recovery. This invention, through a synergistic flotation method that controls the SiO2 / Fe ratio at 0.65–0.75, not only achieves a stable increase in the recovery rates of gold, silver, and copper, but also effectively reduces the valuable metal grade of the iron ore, meeting the stringent standards of magnetic separation processes. It balances the dual process objectives of high recovery rate and low iron ore grade, demonstrating the significant advantages of synergistic treatment of side slag and bottom slag.

[0101] In summary, this invention, by precisely controlling the SiO2 / Fe mass ratio of the mixed slag within the range of 0.65 to 0.75 and combining it with a stepped grinding and flotation process, not only utilizes the differences in the physical properties of the two slags to achieve energy-saving grinding, but also fundamentally optimizes the flotation environment from a fluid dynamics perspective, generating a significant synergistic effect and effectively solving the problems encountered when the two materials are processed separately.

[0102] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for the synergistic flotation recovery of valuable elements from side ash and bottom ash, characterized in that, Includes the following steps: S1. Mix the copper smelting side slag with the copper smelting bottom slag to obtain a mixed slag material; S2. The mixed slag is subjected to a first-stage grinding process to obtain the first slurry; S3. Perform a first flotation operation on the first slurry, adding a pH adjuster, a first activator, a first collector, and a first frother to obtain a first concentrate and a first tailings; S4. The first tailings are subjected to two-stage grinding to obtain the second slurry; S5. Perform a second flotation operation on the second slurry, adding a second activator, a second collector and a second frother to obtain a second concentrate and final tailings. S6. Combine the first concentrate and the second concentrate, and perform a fine-refining operation to obtain the final copper concentrate; In step S1, the mixing ratio of the copper smelting side slag and the copper smelting bottom slag is controlled by mass, with the SiO2 to Fe ratio of the mixed slag material being 0.65 to 0.

75.

2. The method for co-flotation recovery of valuable elements from side ash and bottom ash according to claim 1, characterized in that, In step S1, the copper smelting side slag includes the following components by mass percentage: Cu 0.5%–1.0%, Fe 35%–38%, SiO2 30%–34%, and MgO 1.5%–2.5%.

3. The method for co-flotation recovery of valuable elements from side ash and bottom ash according to claim 1, characterized in that, In step S1, the copper smelting bottom slag comprises the following components by mass percentage: Cu 3%–4%, Fe 40%–44%, SiO2 20%–24%, and MgO ≤0.01%.

4. The method for co-flotation recovery of valuable elements from side ash and bottom ash according to claim 1, characterized in that, In step S2, after the first grinding stage, the proportion of particles with a grinding fineness of -0.074 mm is controlled to be 50% to 70%.

5. The method for co-flotation recovery of valuable elements from side slag and bottom slag according to claim 1, characterized in that, In step S3, the conditions for the first flotation operation include: a pulp concentration of 33%–37% and a pH value of 9–10; the pH adjuster is lime; the activator is sodium sulfide, with an addition amount of 300–500 g / t of mixed residue; the first collector is a mixture of isobutyl xanthate and pentyl xanthate, wherein the mass ratio of isobutyl xanthate to pentyl xanthate is 1:1–2, and the total addition amount is 200–300 g / t of mixed residue; the first frother is pine oil, with an addition amount of 20–60 g / t of mixed residue.

6. The method for co-flotation recovery of valuable elements from side ash and bottom ash according to claim 1, characterized in that, In step S4, after the two-stage grinding, the grinding fineness is controlled so that the proportion of particles with a particle size of -0.074mm is 85% to 90%.

7. The method for co-flotation recovery of valuable elements from side slag and bottom slag according to claim 1, characterized in that, In step S5, the conditions for the second flotation operation include: a pulp concentration of 30%–35% and a pH value of 9–10; the second activator is sodium sulfide, with an addition amount of 50–100 g / t of mixed residue; the second collector is a mixture of isobutyl xanthate and pentyl xanthate, wherein the mass ratio of isobutyl xanthate to pentyl xanthate is 1:1–2, and the total addition amount is 50–100 g / t of mixed residue; the second frother is pine oil, with an addition amount of 5–20 g / t of mixed residue.

8. The method for co-flotation recovery of valuable elements from side ash and bottom ash according to claim 1, characterized in that, Step S5 also includes a step of magnetic separation of the middlings or tailings produced by the second flotation operation to obtain magnetically separated tailings and iron concentrate, wherein the magnetically separated tailings are the final tailings.

9. The method for co-flotation recovery of valuable elements from side ash and bottom ash according to claim 1, characterized in that, In step S6, the refined tailings generated by the refined operation are returned to the grinding process in step S2.

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