A method for resource utilization of neutralized slag and dewatering

Abstract

The present application relates to a kind of neutralization slag synergic dewatering resource utilization method, belong to hazardous waste resource utilization technical field, including the following steps: S1: after waste acid is treated, liquid is removed sulfuric acid and fluorine by gypsum procedure, and produce sewage;S2: after adding lime milk, flocculating agent etc. to sewage and settling, the bottom stream containing neutralization slag is produced;S3: the bottom stream of neutralization thickener is added to slag concentrate slurry, then is sequentially introduced into slag concentrate thickener and vertical filter press, and the slag concentrate mixture is produced;S4: slag concentrate mixture is dosed with copper concentrate and quartz sand, and after the mixed ore after dosing is dried, it is introduced into smelting furnace and smelted, and the smelting slag is produced;S5: smelting slag is processed by slag ore dressing procedure, and the slag tailings and slag concentrate slurry are produced;S6: the bottom stream of neutralization thickener is mixed with slag concentrate slurry to form cycle.The present application solves the problem that the moisture of neutralization slag is high and difficult to dispose and the disposal cost is high, and realizes the resource utilization of valuable metal in neutralization slag.

Description

Technical Field

[0001] This invention relates to a method for the co-dehydration and resource utilization of neutralized slag, belonging to the field of hazardous waste resource utilization technology. Background Technology

[0002] Waste acid from copper smelting plants and other process wastewater are generally treated using a process of first applying gypsum and then neutralizing. In the neutralization process, the gypsum-treated wastewater and other wastewater are thoroughly stirred and reacted with lime slurry. After being clarified and separated by a thickener, the mixture is sent to a neutralization filter press for filtration and separation to produce neutralization residue.

[0003] The neutralization slag is mostly bound water, and currently there is no good filtration process to further reduce its moisture content, nor are there effective measures to dry it quickly, making it difficult to return it to the smelting process for disposal. Currently, some companies are attempting to return it to metallurgical furnaces for disposal by directly adding it to the furnace or by adding new drying facilities for drying.

[0004] However, direct batching, due to its high moisture content and muddy consistency, makes it difficult to mix evenly and easily adheres to other materials, forming large clumps that block the batching process. In severe cases, it can even cause the material to harden and stick to the inner walls of the batching silo, greatly hindering the batching process. Adding drying facilities requires additional equipment for drying, dust collection, and flue gas treatment, and the dehydration speed is slow, resulting in low processing efficiency and high disposal costs.

[0005] Therefore, copper smelting companies currently mainly outsource the disposal to qualified companies and pay disposal fees. Downstream qualified companies primarily use methods for treating neutralization slag, including incineration, stabilization / solidification, and co-processing in cement kilns.

[0006] The incineration process involves mixing neutralization residue with other solid wastes and then incinerating it in a rotary kiln. The flue gas is then discharged after being cooled, dusted, desulfurized, and denitrified. Residue and ash are sampled and analyzed. If the residue meets the landfill standards, it is directly and safely landfilled. If the analysis and testing show that the residue does not meet the landfill standards, it is further stabilized / solidified before being safely landfilled.

[0007] The stabilization / solidification process involves mixing neutralized slag and other hazardous waste with stabilizers such as lime and cement, followed by thorough mixing, temporary storage and curing, and finally, after sampling and analysis confirming compliance, safe landfill disposal. Cement kiln co-processing involves mixing neutralized slag with other raw materials, preheating, and then adding it to a decomposition furnace and rotary kiln for drying and calcination to produce cement clinker for cement manufacturing.

[0008] However, after incineration and stabilization / solidification, the waste needs to be safely landfilled, which fails to achieve the resource utilization of the neutralization slag. The co-processing in cement kilns also fails to recover valuable metals from the waste, and there is also the risk that impurity metals will affect subsequent processes. Therefore, improvements are urgently needed. Summary of the Invention

[0009] To overcome the shortcomings of existing copper smelting neutralization slag, such as high moisture content, poor treatment effect, and waste of resources due to the lack of recycling and reuse processes, this invention designs a method for the co-dehydration and resource utilization of neutralization slag. This method solves the problems of high moisture content, difficulty in disposal, and high disposal costs of neutralization slag, and realizes the comprehensive recycling and utilization of valuable metals in neutralization slag.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] A method for the co-dewatering and resource utilization of neutralized residue includes the following steps:

[0012] S1: The waste acid solution generated from copper smelting is treated and then processed through a gypsum board process to remove sulfuric acid and fluorine, generating wastewater in the process;

[0013] S2: Add lime milk, flocculant and wastewater from other processes in copper smelting to the wastewater generated in step S1 for neutralization, and pass the neutralized mixture into a neutralization thickener for sedimentation to produce underflow containing neutralization slag.

[0014] S3: Add the underflow from the neutralizing thickener in step S2 to the slag concentrate slurry, and then pass it through the slag concentrate thickener and the vertical filter press in sequence to produce a slag concentrate mixture;

[0015] S4: The slag concentrate mixture produced in step S3 is batched with copper concentrate and quartz sand. After the batched slag concentrate is dried, it is fed into a smelting furnace for high-temperature smelting. During the high-temperature smelting process, a slag-forming reaction will occur, producing smelting slag.

[0016] S5: The smelting slag produced in step S4 is processed through a slag beneficiation process to produce slag tailings and slag concentrate slurry;

[0017] S6: The underflow from the neutralizing thickener in step S2 is mixed with the slag concentrate slurry produced in step S5 to form a cycle.

[0018] Furthermore, the main chemical reactions occurring in the slag-forming reaction of the neutralized slag in the slag concentrate mixture in step S4 are as follows:

[0019] CaSO4·2H2O→CaSO4+2H2O;

[0020] CaSO4→CaO+SO2+O2;

[0021] Ca(OH)2→CaO+H2O;

[0022] 2Fe3O4+3CaSO4→3CaFe2O4+3SO2+O2;

[0023] 2CaSO4+SiO2→Ca2SiO4+2SO2+O2.

[0024] Furthermore, in step S3, the underflow from the neutralizing thickener is output through a delivery pump, and the delivery pump is a variable frequency pump.

[0025] Furthermore, the output flow rate of the variable frequency pump is 5–30 m³ / h. 3 / h.

[0026] Furthermore, the neutralized slag output from the neutralization thickener accounts for 1% to 15% of the slag concentrate mixture.

[0027] Furthermore, in step S3, the pH value of the underflow from the neutralizing thickener is 9.2-10, and the water content of the slag concentrate mixture is 8-14%.

[0028] Furthermore, in step S3, the resulting slag concentrate mixture is in a loose state.

[0029] Furthermore, in step S5, the copper content of the tailings is stabilized at 0.15% to 0.19%.

[0030] Furthermore, in step S5, the smelting slag is slowly cooled and crushed before entering the slag beneficiation process.

[0031] Furthermore, the underflow from the neutralizing thickener in step S2 is added to the slag concentrate slurry, and the slag concentrate slurry is entirely the slag concentrate slurry produced in step S5.

[0032] Compared with the prior art, the present invention has the following features and beneficial effects:

[0033] In this invention, by mixing the underflow reflux from the neutralizing thickener with the slag concentrate slurry, the problems of high moisture content in neutralizing slag, difficulty in disposal, and high disposal costs can be effectively solved. This also facilitates faster settling of the slag concentrate and improves the pH value in the beneficiation process. The resulting slag concentrate mixture participates in the slag-forming reaction during smelting, which helps reduce the melting point and viscosity of the slag, improves the properties of the smelting slag, and comprehensively recovers valuable metals such as copper brought in by the neutralizing slag, achieving comprehensive resource recovery and utilization of valuable metals in the neutralizing slag. After participating in the smelting slag-forming reaction, the neutralizing slag enters the slag beneficiation process, where the gangue components such as calcium enter the tailings and can be used as raw materials for cement manufacturing, achieving the harmless disposal and comprehensive utilization of the neutralizing slag. This reduces the disposal costs of neutralizing slag for copper smelting enterprises, as well as the resource consumption and potential environmental risks during the transfer and downstream disposal of neutralizing slag. Attached Figure Description

[0034] Figure 1 This is a process flow diagram of the present invention. Detailed Implementation

[0035] The present invention will now be described in more detail with reference to the embodiments.

[0036] like Figure 1 As shown, a method for the co-dewatering and resource utilization of neutralization residue includes the following steps:

[0037] S1: The waste acid solution generated from copper smelting is treated and then processed through a gypsum board process to remove sulfuric acid and fluorine, generating wastewater in the process;

[0038] S2: The wastewater generated in step S1 is mixed with the wastewater generated in other processes during copper smelting, and lime milk and flocculant are added to neutralize it. The neutralized mixture is then passed into a neutralization thickener for settling, producing an underflow containing neutralization slag.

[0039] The main components of the neutralization residue are CaSO4·2H2O and some unreacted Ca(H0)2, as well as a small amount of copper, and impurities such as iron, arsenic, lead, and zinc.

[0040] S3: Add the underflow from the neutralizing thickener in step S2 to the slag concentrate slurry, and then pass it through the slag concentrate thickener and the vertical filter press in sequence to produce a slag concentrate mixture;

[0041] In this process, the slag concentrate slurry and the underflow containing neutralization slag are thoroughly mixed in the slag concentrate thickener. The small amount of flocculant and unreacted calcium hydroxide remaining in the neutralization slag have a good flocculation effect, which can effectively promote the coagulation and growth of fine particles in the mixed slurry. These particles, along with the slag concentrate in the slag concentrate slurry and the calcium sulfate in the neutralization slag, settle together, thereby accelerating the settling process.

[0042] During the flocculation and synergistic sedimentation process, fine particles agglomerate into larger particles, and calcium sulfate and slag concentrate are fully mixed. The moisture content of the slag concentrate mixture produced by the synergistic effect is much lower than that of the neutralized slag after separate filtration, and also lower than that of the mixture after separate filtration of the neutralized slag and slag concentrate. The moisture content of the produced slag concentrate mixture can be stably controlled at 8% to 14%.

[0043] At the same time, a vertical filter press is set up to dewater the mixture after preliminary clarification and separation by the slag concentrate thickener, producing a mixed mineral of slag concentrate and neutralization slag that is uniformly mixed, namely slag concentrate mixture. This material is loose and can smoothly participate in the subsequent batching process.

[0044] In particular, after the underflow from the neutralizing thickener settles together with the slag concentrate slurry, the supernatant in the slag concentrate thickener can be returned to the slag beneficiation process to adjust the pH value of the slag beneficiation process.

[0045] S4: The slag concentrate mixture produced in step S3 is batched with copper concentrate and quartz sand. After drying, the batched ore is fed into a smelting furnace for high-temperature smelting. A slag-forming reaction will occur during the high-temperature smelting process.

[0046] Production of smelting slag;

[0047] S5: The smelting slag produced in step S4 is processed through a slag beneficiation process to produce slag tailings and slag concentrate slurry;

[0048] S6: The underflow from the neutralizing thickener in step S2 is mixed with the slag concentrate slurry produced in step S5 to form a cycle.

[0049] As can be seen from the above description, the beneficial effects of the present invention are as follows: by mixing the underflow of the neutralizing thickener with the slag concentrate slurry, and through synergistic dewatering, a slag concentrate mixture with low moisture content is produced, which can effectively solve the problems of high moisture content of neutralizing slag, difficulty in returning it to the process, and high disposal costs. It is also beneficial to accelerate the settling of slag concentrate and improve the pH value of the mineral processing process.

[0050] The resulting slag concentrate mixture participates in the slag-forming reaction during the smelting process, which is conducive to reducing the melting point and viscosity of the slag, improving the properties of the smelting slag, and comprehensively recovering valuable metals such as copper brought in by the neutralization slag, thus realizing the resource-based comprehensive recovery and utilization of valuable metals in the neutralization slag.

[0051] After the neutralized slag participates in the smelting and slag-forming reaction, it enters the slag beneficiation process. The gangue components such as calcium in it enter the tailings and can be used as raw materials for cement manufacturing, thus realizing the harmless treatment and comprehensive utilization of the neutralized slag.

[0052] Neutralization slag is hazardous waste. This invention can effectively reduce the disposal costs of neutralization slag for copper smelting enterprises, as well as the resource consumption and potential environmental risks during the transfer and disposal of neutralization slag by downstream enterprises.

[0053] Furthermore, the main chemical reactions occurring in the slag-forming reaction of the neutralized slag in the slag concentrate mixture in step S4 are as follows:

[0054] CaSO4·2H2O→CaSO4+2H2O;

[0055] CaSO4→CaO+SO2+O2;

[0056] Ca(OH)2→CaO+H2O;

[0057] 2Fe3O4+3CaSO4→3CaFe2O4+3SO2+O2;

[0058] 2CaSO4+SiO2→Ca2SiO4+2SO2+O2.

[0059] As can be seen from the above description, specifically, CaSO4·2H2O and Ca(H0)2 in the slag concentrate mixture further decompose into CaO to participate in the slag-forming reaction. Among them, CaSO4 can also directly participate in the slag-forming reaction. The participation of calcium substances in the slag-forming reaction is beneficial to reducing the melting point and viscosity of the smelting slag, which is of great help to reduce the smelting temperature control, improve the properties of the smelting slag, thereby reducing the copper content in the smelting slag and stabilizing the furnace condition control. In addition, valuable metals such as copper brought in by the neutralization slag are also comprehensively recovered and utilized in the smelting process.

[0060] Furthermore, in step S3, the underflow from the neutralizing thickener is output through a delivery pump, which is a variable frequency pump.

[0061] As can be seen from the above description, the variable frequency pump can control the delivery flow rate through frequency conversion, thereby controlling the concentration of the underflow of the thickener. It is convenient, quick, and suitable for promotion and use.

[0062] Furthermore, the output flow rate of the variable frequency pump is 5–30 m³ / h. 3 / h.

[0063] Furthermore, the neutralized slag output from the neutralization thickener accounts for 1% to 15% of the slag concentrate mixture.

[0064] Furthermore, in step S3, the pH value of the underflow from the neutralizing thickener is 9.2-10, and the water content of the slag-concentrate mixture is 8-14%.

[0065] Furthermore, in step S3, the resulting slag concentrate mixture is in a loose state.

[0066] As can be seen from the above description, the loosely formed slag concentrate mixture meets the requirements for subsequent batching and facilitates subsequent processing.

[0067] Furthermore, in step S5, the copper content of the tailings is stabilized at 0.15% to 0.19%.

[0068] Furthermore, in step S5, the smelting slag is slowly cooled and crushed before entering the slag beneficiation process.

[0069] Furthermore, the underflow from the neutralizing thickener in step S2 is added to the slag concentrate slurry, and the slag concentrate slurry is entirely the slag concentrate slurry produced in step S5.

[0070] Example 1

[0071] The method for resource utilization of neutralized residue through co-dehydration in this embodiment includes the following steps:

[0072] S1: The waste acid solution generated from copper smelting is treated and then processed through a gypsum board process to remove sulfuric acid and fluorine, generating wastewater in the process;

[0073] S2: The wastewater generated in step S1 is mixed with the wastewater generated in other processes during copper smelting, and lime milk and flocculant are added to neutralize it. The neutralized mixture is then passed into a neutralization thickener for settling, producing an underflow containing neutralization slag.

[0074] S3: Add the underflow from the neutralization and thickening machine in step S2 to the slag concentrate slurry. The underflow from the neutralization and thickening machine is pumped by a frequency converter to achieve an output flow rate of 5m³ / h. 3 The output is per hour, and the mixture is sequentially passed through a slag concentrate thickener and a vertical filter press to produce a slag concentrate mixture. The neutralized slag output from the neutralization thickener accounts for 2.5% of the slag concentrate mixture; the pH value of the underflow from the neutralization thickener is 9.4; and the water content of the produced slag concentrate mixture is 9.3%.

[0075] S4: The slag concentrate mixture produced in step S3 is batched with copper concentrate and quartz sand. After the batched slag concentrate is dried, it is fed into a smelting furnace for high-temperature smelting. During the high-temperature smelting process, a slag-forming reaction will occur, producing smelting slag.

[0076] S5: The smelting slag produced in step S4 is processed through a slag beneficiation process to produce slag tailings and slag concentrate slurry, wherein the copper content of the slag tailings is 0.18%.

[0077] S6: The underflow from the neutralizing thickener in step S2 is mixed with the slag concentrate slurry produced in step S5 to form a cycle.

[0078] Furthermore, the main chemical reactions occurring in the slag-forming reaction of the neutralized slag in the slag concentrate mixture in step S4 are as follows:

[0079] CaSO4·2H2O→CaSO4+2H2O;

[0080] CaSO4→CaO+SO2+O2;

[0081] Ca(OH)2→CaO+H2O;

[0082] 2Fe3O4+3CaSO4→3CaFe2O4+3SO2+O2;

[0083] 2CaSO4+SiO2→Ca2SiO4+2SO2+O2.

[0084] Furthermore, in step S3, the resulting slag concentrate mixture is in a loose state.

[0085] Furthermore, the underflow from the neutralizing thickener in step S2 is added to the slag concentrate slurry, and the slag concentrate slurry is entirely the slag concentrate slurry produced in step S5.

[0086] In this embodiment, the content of each component in the slag concentrate mixture is shown in Table 1 below:

[0087]

[0088] Table 1

[0089] The moisture content is 9.3%.

[0090] Example 2

[0091] The method for resource utilization of neutralized residue through co-dehydration in this embodiment includes the following steps:

[0092] S1: The waste acid solution generated from copper smelting is treated and then processed through a gypsum board process to remove sulfuric acid and fluorine, generating wastewater in the process;

[0093] S2: The wastewater generated in step S1 is mixed with the wastewater generated in other processes during copper smelting, and lime milk and flocculant are added to neutralize it. The neutralized mixture is then passed into a neutralization thickener for settling, producing an underflow containing neutralization slag.

[0094] S3: Add the underflow from the neutralizing and thickening machine in step S2 to the slag concentrate slurry. The underflow from the neutralizing and thickening machine is pumped by a frequency converter to achieve an output flow rate of 15m³ / h. 3 The output is per hour, and the mixture is sequentially passed through a slag concentrate thickener and a vertical filter press to produce a slag concentrate mixture. The neutralized slag output from the neutralization thickener accounts for 7.5% of the slag concentrate mixture. The pH value of the underflow from the neutralization thickener is 9.5. The water content of the produced slag concentrate mixture is 10.53%.

[0095] S4: The slag concentrate mixture produced in step S3 is batched with copper concentrate and quartz sand. After the batched slag concentrate is dried, it is fed into a smelting furnace for high-temperature smelting. During the high-temperature smelting process, a slag-forming reaction will occur, producing smelting slag.

[0096] S5: The smelting slag produced in step S4 is processed through a slag beneficiation process to produce tailings and slag concentrate slurry, wherein the copper content of the tailings is 0.16%.

[0097] S6: The underflow from the neutralizing thickener in step S2 is mixed with the slag concentrate slurry produced in step S5 to form a cycle.

[0098] Furthermore, the main chemical reactions occurring in the slag-forming reaction of the neutralized slag in the slag concentrate mixture in step S4 are as follows:

[0099] CaSO4·2H2O→CaSO4+2H2O;

[0100] CaSO4→CaO+SO2+O2;

[0101] Ca(OH)2→CaO+H2O;

[0102] 2Fe3O4+3CaSO4→3CaFe2O4+3SO2+O2;

[0103] 2CaSO4+SiO2→Ca2SiO4+2SO2+O2.

[0104] Furthermore, in step S3, the resulting slag concentrate mixture is in a loose state.

[0105] Furthermore, the underflow from the neutralizing thickener in step S2 is added to the slag concentrate slurry, and the slag concentrate slurry is entirely the slag concentrate slurry produced in step S5.

[0106] In this embodiment, the content of each component in the slag concentrate mixture is shown in Table 2 below:

[0107]

[0108] Table 2

[0109] The moisture content is 10.53%.

[0110] Example 3

[0111] The method for resource utilization of neutralized residue through co-dehydration in this embodiment includes the following steps:

[0112] S1: The waste acid solution generated from copper smelting is treated and then processed through a gypsum board process to remove sulfuric acid and fluorine, generating wastewater in the process;

[0113] S2: The wastewater generated in step S1 is mixed with the wastewater generated in other processes during copper smelting, and lime milk and flocculant are added to neutralize it. The neutralized mixture is then passed into a neutralization thickener for settling, producing an underflow containing neutralization slag.

[0114] S3: Add the underflow from the neutralizing and thickening machine in step S2 to the slag concentrate slurry. The underflow from the neutralizing and thickening machine is pumped by a frequency converter to achieve an output flow rate of 30 m³ / h. 3 The output is per hour, and the mixture passes through a slag concentrate thickener and a vertical filter press in sequence to produce a slag concentrate mixture. The neutralized slag output from the neutralization thickener accounts for 15% of the slag concentrate mixture. The pH value of the underflow from the neutralization thickener is 9.8. The water content of the produced slag concentrate mixture is 12.54%.

[0115] S4: The slag concentrate mixture produced in step S3 is batched with copper concentrate and quartz sand. After the batched slag concentrate is dried, it is fed into a smelting furnace for high-temperature smelting. During the high-temperature smelting process, a slag-forming reaction will occur, producing smelting slag.

[0116] S5: The smelting slag produced in step S4 is processed through a slag beneficiation process to produce slag tailings and slag concentrate slurry, wherein the copper content of the slag tailings is 0.17%.

[0117] S6: The underflow from the neutralizing thickener in step S2 is mixed with the slag concentrate slurry produced in step S5 to form a cycle.

[0118] Furthermore, the main chemical reactions occurring in the slag-forming reaction of the neutralized slag in the slag concentrate mixture in step S4 are as follows:

[0119] CaSO4·2H2O→CaSO4+2H2O;

[0120] CaSO4→CaO+SO2+O2;

[0121] Ca(OH)2→CaO+H2O;

[0122] 2Fe3O4+3CaSO4→3CaFe2O4+3SO2+O2;

[0123] 2CaSO4+SiO2→Ca2SiO4+2SO2+O2.

[0124] Furthermore, in step S3, the resulting slag concentrate mixture is in a loose state.

[0125] Furthermore, the underflow from the neutralizing thickener in step S2 is added to the slag concentrate slurry, and the slag concentrate slurry is entirely the slag concentrate slurry produced in step S5.

[0126] In this embodiment, the content of each component in the slag concentrate mixture is shown in Table 3 below:

[0127]

[0128] Table 3

[0129] The moisture content is 12.54%.

[0130] Example 4

[0131] In contrast to Example 1, this example only dewaters the underflow from the neutralization thickener, and the final composition of the neutralization sludge is shown in Table 4 below:

[0132]

[0133] Table 4

[0134] The moisture content is as high as 74.11%.

[0135] Example 5

[0136] In contrast to Example 1, this example only dewaters the slag concentrate, and the components of the final neutralized slag are shown in Table 5 below:

[0137] Cu Bi Fe S <![CDATA[SiO2]]> CaO MgO <![CDATA[Al2O3]]> Pb As Sb Zn <![CDATA[H20]]> Slag concentrate 20.37 0.02 26.75 5.50 20.41 2.60 0.72 4.44 0.43 2.85 0.10 1.21 8.84

[0138] Table 5

[0139] The moisture content is 8.84%.

[0140] To better illustrate this, Tables 1-5 are summarized into Table 6 as follows:

[0141]

[0142] Table 6

[0143] In summary, this invention controls the underflow of the neutralization slag thickener to 5–30 m. 3 When the flow rate of the slag concentrate mixture is / h, the moisture content is stable between 8% and 14%, and it shows an upward trend as the flow rate of the neutralizing thickener underflow increases. In this invention, by mixing the underflow of the neutralizing thickener with the slag concentrate slurry, the problems of high moisture content in the neutralizing slag, difficulty in handling, and high handling costs can be effectively solved. It is also beneficial to accelerate the settling of the slag concentrate and improve the pH value of the mineral processing process.

[0144] In the description of this invention, it should be noted that the terms "inner", "outer", "upper", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0145] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the term "connection" should be interpreted broadly. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0146] Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

Claims

1. A method for the co-dewatering and resource utilization of neutralization residue, characterized in that: Includes the following steps: S1: The waste acid solution generated from copper smelting is treated and then processed through a gypsum board process to remove sulfuric acid and fluorine, generating wastewater in the process; S2: Add lime milk, flocculant and wastewater from other processes in copper smelting to the wastewater generated in step S1 for neutralization, and pass the neutralized mixture into a neutralization thickener for sedimentation to produce underflow containing neutralization slag. S3: Add the underflow from the neutralizing thickener in step S2 to the slag concentrate slurry, and then pass it through the slag concentrate thickener and the vertical filter press in sequence to produce a slag concentrate mixture; S4: The slag concentrate mixture produced in step S3 is batched with copper concentrate and quartz sand. After the batched slag concentrate is dried, it is fed into a smelting furnace for high-temperature smelting. During the high-temperature smelting process, a slag-forming reaction will occur, producing smelting slag. S5: The smelting slag produced in step S4 is processed through a slag beneficiation process to produce slag tailings and slag concentrate slurry; S6: The underflow from the neutralizing thickener in step S2 is mixed with the slag concentrate slurry produced in step S5 to form a cycle; In step S3, the pH value of the underflow from the neutralization thickener is 9.2~10, and the water content of the slag-concentrate mixture is 8~14%. In step S3, the resulting slag concentrate mixture is in a loose state.

2. The method for co-dewatering and resource utilization of neutralization residue according to claim 1, characterized in that: The main chemical reaction of the slag-forming reaction in the neutralized slag in the slag concentrate mixture in step S4 is as follows: CaSO4•2H2O→CaSO4+2H2O; CaSO4→CaO+SO2+O2; Ca(OH)2→CaO+H2O; 2Fe3O4+3CaSO4→3CaFe2O4+3SO2+O2; 2CaSO4+SiO2→Ca2SiO4+2SO2+O2.

3. The method for co-dewatering and resource utilization of neutralization residue according to claim 1, characterized in that: In step S3, the underflow from the neutralizing thickener is output through a delivery pump, and the delivery pump is a variable frequency pump.

4. The method for co-dewatering and resource utilization of neutralized residue according to claim 3, characterized in that: The output flow rate of the variable frequency pump is 5~30 m3 / h.

5. The method for co-dewatering and resource utilization of neutralization residue according to claim 1, characterized in that: The neutralized slag output from the neutralization thickener accounts for 1% to 15% of the slag concentrate mixture.

6. The method for co-dewatering and resource utilization of neutralization residue according to claim 1, characterized in that: In step S5, the copper content of the tailings is stabilized at 0.15%~0.19%.

7. The method for co-dewatering and resource utilization of neutralized residue according to claim 1, characterized in that: In step S5, the smelting slag is slowly cooled and crushed before entering the slag beneficiation process.

8. The method for co-dewatering and resource utilization of neutralized residue according to claim 1, characterized in that: The underflow from the neutralizing thickener in step S2 is added to the slag concentrate slurry, and the slag concentrate slurry is entirely the slag concentrate slurry produced in step S5.

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