A method for treating hydrometallurgical raffinate

Abstract

The application relates to a treatment method of hydrometallurgical raffinate, which comprises the following steps: performing a fractional co-precipitation reaction on the raffinate by using characteristic seeds in the presence of an alkalizing agent until the heavy metal content in the raffinate is less than 10 mg / L and the COD is less than 300 mg / L. The treatment method provided by the application recycles the characteristic seeds as renewable resources, can realize synchronous removal of organic matters and heavy metal ions in the raffinate wastewater and resource recovery, the COD of the raffinate effluent is less than 300 mg / L, the concentration of heavy metal ions is less than 10 mg / L, the heavy metal recovery rate is more than 98%, the hydraulic retention time is short, the turbidity of the effluent is small, no sludge is produced, no secondary pollution is caused, and the cost is effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of metallurgical wastewater treatment, and particularly relates to a treatment method of raffinate in hydrometallurgy. BACKGROUND

[0002] With the rapid development and popularization of the new energy industry in China, as a key component of the positive material of ternary lithium battery, the demand for cobalt sulfate and nickel sulfate is continuously increasing. At present, the wet metallurgical process is generally used to purify and enrich cobalt and nickel in raw ore, waste batteries and industrial catalysts. The hydrometallurgical technology is to contact ores, concentrates enriched by ore dressing or other raw materials with aqueous solution or other solution, to transfer the target metal from the solid phase to the liquid phase through chemical reaction, then to separate and enrich various useful metals contained in the liquid phase, and finally to recover them in the form of metal or other compounds. It mainly includes leaching, solid-liquid separation, solution purification, solution metal extraction and wastewater treatment. While recovering metal elements from leaching solution in the extraction process, a large amount of raffinate wastewater is generated, which has the water quality characteristics of complex and high content of organic matter and high salt content.

[0003] In the hydrometallurgical industry, the commonly used metal extractants mainly include acidic extractants, neutral extractants and alkaline extractants. At present, P204, P507 and Cyanex272 extractants are mainly used in the extraction process of separating nickel and cobalt non-ferrous metal elements. In the extraction process stage, the extractant needs to be diluted with solvents such as sulfonated kerosene to form an extraction organic phase with a certain concentration, and then saponified with an alkaline solution. Due to the decomposition and aging of the extractant and the diluent, and the hydrophilicity of the extractant itself, a part of oil substances is inevitably carried in the raffinate and stripping solution, thereby increasing the concentration of organic matter in the raffinate wastewater.

[0004] Taking the cobalt-nickel extraction process of an enterprise as an example, the organic matter in the nickel soap raffinate includes a small amount of dispersed oil, extractants P204, P257, soluble sulfonated kerosene and metal complexes. Since the extractant is generally stable in nature, and a large amount of acid, alkali and salt are introduced into the system during smelting, it is difficult to treat by biological method. At present, the pretreatment-MVR evaporation crystallization combined process is mainly used for deep treatment of the raffinate wastewater. Among them, the pretreatment such as gravity separation, reagent coagulation, air flotation and filtration has no obvious effect on the treatment of raffinate; and the advanced oxidation technologies such as photo-Fenton, electro-Fenton, persulfate method and ozone catalytic oxidation proposed by many researchers mainly have the advantages of no secondary pollution, good oxidation and decolorization effect, but cannot realize the removal and recycling of metal ions in the raffinate.

[0005] In order to ensure that the COD and heavy metal ions of the raffinate wastewater in the hydrometallurgy industry meet the standards and reduce the treatment cost, it is of great significance to study a more effective and lower cost treatment method. SUMMARY

[0006] In order to solve the above technical problems, the application provides a treatment method for hydrometallurgy raffinate, which uses characteristic crystal seeds as mass centers to attract and destabilize pollutants to form dense granules, removes organic matter and metal ions by discharging the granules, recycles and reuses heavy metals by acid leaching of the characteristic crystal seeds, and finally obtains effluent with COD less than 300 mg / L and heavy metal ion concentration less than 10 mg / L, and heavy metal resource recovery rate more than 98%.

[0007] In the first aspect, the application provides a treatment method for hydrometallurgy raffinate, which comprises the following steps:

[0008] In the presence of an alkalizing agent, the raffinate is subjected to fractional co-precipitation reaction using characteristic crystal seeds until the heavy metal content in the raffinate is less than 10 mg / L and the COD is less than 300 mg / L.

[0009] The raffinate described in the application is hydrometallurgy raffinate wastewater, and the application does not limit its composition and content too much. The raffinate after extraction by P204, P207 or Cyanex272 and the like is suitable for the application. Exemplarily, the raffinate includes dispersants, extractants, solvent oil, sulfonated kerosene, nickel ions, cobalt ions and the like, and the heavy metals include nickel, cobalt and the like.

[0010] The treatment method provided by the application is based on the granulation coagulation theory, uses characteristic crystal seeds as renewable resources for recycling, can realize the synchronous removal of organic matter and heavy metal ions in the raffinate wastewater and resource recycling, finally obtains effluent with COD less than 300 mg / L, heavy metal ion concentration less than 10 mg / L, and heavy metal recovery rate more than 98%, and effectively reduces the process cost.

[0011] As a preferred technical solution of the application, the treatment method comprises the following steps:

[0012] (1) placing the characteristic crystal seeds in a fluidized bed;

[0013] (2) passing the raffinate into the fluidized bed for fractional co-precipitation reaction to obtain fractional raffinate, wherein the co-precipitation reaction of each stage is carried out in the presence of an alkalizing agent;

[0014] (3) when the heavy metal content in the fractional raffinate is less than 10 mg / L and the COD is less than 300 mg / L, the treatment is completed.

[0015] The fluidized bed is a reactor for making solid particles in suspended motion and carrying out liquid-solid phase reaction process by using liquid (raffinate) to pass through the layer of granular solid (characteristic seed).

[0016] The reaction mechanism of the treatment method is as follows, Figure 1 The reaction mechanism of the treatment method is as follows,

[0017] (1) When organic compounds and heavy metal ions coexist in a reaction unit, the oxygen-containing functional groups on the organic matter are easy to complex with positively charged metal ions to form Me 2+ - organic compounds;

[0018] (2) In the process of introducing the alkalizing agent, the enrichment of metal ions on the surface of the characteristic seed enhances its co-precipitation ability, so that the organic matter and Me 2+ - organic compounds are co-precipitated on the surface of the characteristic seed;

[0019] (3) Under appropriate hydraulic conditions, the collision frequency between metal ions and characteristic seeds changes, so that the mass transfer of crystal growth is accelerated;

[0020] (4) In the subsequent process, the metal precipitates and organic matter attached to the characteristic seed act as a new carrier to realize the densification of the product through the common ion effect and surface complexation, and finally realize the synchronous removal of organic matter and metal ions by discharging the characteristic seed;

[0021] (5) By acid leaching the characteristic seed, the leaching solution is discharged to the process extraction unit to realize the recycling of the heavy metal resources loaded on the characteristic seed.

[0022] Based on the theoretical basis of granulation coagulation technology and combined with the reaction process of the fluidized bed, the core crystal agglomeration induced granulation technology for promoting the growth of flocculation body is proposed, which is characterized by taking the characteristic seed as the core and the remaining substances adhering or gathering around it. Compared with the traditional coagulation technology, the addition of the characteristic seed in the present application provides a site for the attachment of organic matter and reduces the reaction activation energy through the crystallization process to provide a preferential surface area for ion reaction.

[0023] As a preferred technical solution of the present application, the treatment method comprises the following steps:

[0024] (1) placing the characteristic seed in the fluidized bed;

[0025] (2) introducing the raffinate into the fluidized bed for staged co-precipitation reaction, and obtaining the staged raffinate after the reaction, adjusting the pH value of the staged raffinate, and introducing it into the fluidized bed again for the next stage of staged co-precipitation reaction;

[0026] In the hierarchical co-precipitation reaction, each stage of the co-precipitation reaction is carried out in the presence of an alkalizing agent.

[0027] (3) repeating step (2) until the content of heavy metals in the hierarchical raffinate is less than 10 mg / L and the COD is less than 300 mg / L, and the treatment is completed.

[0028] As a preferred technical solution of the present application, the average particle size of the characteristic seed crystal is 0.2-0.3 mm, such as 0.22 mm, 0.24 mm, 0.26 mm, 0.28 mm, etc.

[0029] The present application provides a new treatment method for hydrometallurgical raffinate, i.e. a nucleation granulation method, which uses characteristic seed crystals as mass centers to attract and destabilize pollutants to form dense granules, and removes organic matter and metal ions and recovers heavy metals by discharging the granules.

[0030] As a preferred technical solution of the present application, the volume of the characteristic seed crystal is 20-35% of the volume of the fluidized bed, such as 22%, 24%, 26%, 28%, 30%, 32%, 34%, etc.

[0031] As a preferred technical solution of the present application, the hourly flow rate of the raffinate is 15-25 times the volume of the fluidized bed, such as 18 times, 20 times, 22 times, 24 times, etc.

[0032] As a preferred technical solution of the present application, the hourly flow rate of the raffinate is 15-25 times the volume of the fluidized bed, such as 18 times, 20 times, 22 times, 24 times, etc.

[0033] The treatment method provided by the present application has a short hydraulic retention time, low effluent turbidity, no sludge production, and no secondary pollution.

[0034] As a preferred technical solution of the present application, the alkalizing agent is introduced into the fluidized bed in the form of an alkalizing agent solution.

[0035] As a preferred technical solution of the present application, the flow rate of the alkalizing agent solution is 10-20% of the flow rate of the raffinate in the corresponding hierarchical co-precipitation reaction, such as 12%, 14%, 16%, 18%, etc.

[0036] As a preferred technical solution of the present application, in the hierarchical co-precipitation reaction, the concentration of the alkalizing agent is 4000-10000 mg / L, such as 5000 mg / L, 6000 mg / L, 7000 mg / L, 8000 mg / L, 9000 mg / L, etc.

[0037] This application achieves the removal of organic matter and metal ions by controlling appropriate hydraulic and alkalinity conditions to promote the continuous aggregation and densification of characteristic seed crystals and destabilized pollutants.

[0038] As a preferred technical solution of this application, when the heavy metal content in the fractionated raffinate is greater than 350 mg / L, the concentration of the alkalizing agent is 4000-6000 mg / L.

[0039] As a preferred technical solution of this application, when the heavy metal content in the fractionated raffinate is less than 350 mg / L, the concentration of the alkalizing agent is 6000-10000 mg / L.

[0040] When the heavy metal content is below 350 mg / L, increase the amount of alkalizing agent to 6000-10000 mg / L so that a small amount of heavy metal in the raffinate co-precipitates, thereby making the heavy metal content in the final raffinate below 10 mg / L.

[0041] In a preferred embodiment of this application, the concentration of the alkalizing agent increases progressively in the graded coprecipitation reaction. It is understood that this progressive increase in the concentration of the alkalizing agent means that the concentration of the alkalizing agent in the next stage of the coprecipitation reaction is higher than the concentration of the alkalizing agent in the previous stage.

[0042] As a preferred technical solution of this application, in step (2), the pH value of the adjusted fractionated raffinate is 7-8.5, such as 7.2, 7.4, 7.6, 7.8, 8.0, 8.2, 8.4, etc.

[0043] As a preferred technical solution of this application, when the heavy metal content in the fractionated raffinate is greater than 350 mg / L, the pH value of the fractionated raffinate is adjusted to 7-7.5, such as 7.1, 7.2, 7.3, 7.4, etc.

[0044] As a preferred technical solution of this application, when the heavy metal content in the fractionated raffinate is less than 350 mg / L, the pH value of the fractionated raffinate is adjusted to 7.5-8.5.

[0045] As a preferred technical solution of this application, in the fractional coprecipitation reaction, the pH value of the fractional raffinate increases step by step. It can be understood that the step-by-step increase in pH value of the fractional raffinate means that the pH value of the fractional raffinate in the next coprecipitation reaction is higher than the pH value of the fractional raffinate in the previous coprecipitation reaction. More specifically, for example, in step (2), the pH value of the obtained fractional raffinate is adjusted to m1, the next fractional coprecipitation reaction is carried out, the next fractional raffinate is obtained, its pH value is adjusted to m2, and the next fractional coprecipitation reaction is continued, where m2>m1.

[0046] The fluidized bed is not limited in the present application, as long as it can be applied to the present application and achieve the purpose of the present application.

[0047] As a preferred technical solution of the present application, the fluidized bed in step (1) is an upflow fluidized bed. When the fluidized bed is an upflow fluidized bed, the raffinate, the alkalizing agent and the characteristic seed can be fully mixed and contacted, and the mass transfer effect can be improved.

[0048] As a preferred technical solution of the present application, the pH value of the raffinate in step (2) is 6-7. Generally, the pH of the raffinate is about 4. In the present application, the pH of the raffinate is adjusted to 6-7 by the alkalizing agent, which is close to neutral, and is more conducive to the subsequent fractional co-precipitation reaction.

[0049] As a preferred technical solution of the present application, the alkalizing agent is selected from sodium hydroxide and / or sodium carbonate.

[0050] As a preferred technical solution of the present application, the reaction temperature of the fractional co-precipitation reaction is independently 5-35℃, such as 10℃, 15℃, 20℃, 25℃, 30℃, etc.

[0051] As a preferred technical solution of the present application, the pH regulator of the fractional raffinate is selected from sulfuric acid and / or nitric acid. Because the fractional co-precipitation reaction is carried out in the presence of the alkalizing agent, the pH of the obtained fractional raffinate is strongly alkaline. On the one hand, the pH of the fractional raffinate can be adjusted to ensure that the heavy metal ions and the organic matter can be precipitated and attached to the characteristic seed after the alkalizing agent is added in the next stage, so as to be removed. On the other hand, it can prevent the pH of the water from being too high, which can cause the turbidity of the effluent to increase and affect the water quality.

[0052] As a preferred technical solution of the present application, the treatment method further comprises acid leaching treatment on the characteristic seed after the treatment is completed.

[0053] The present application performs acid leaching treatment on the characteristic seed after the treatment is completed, so as to recover the heavy metals, and the recovery rate reaches more than 98%. The removal rate of the heavy metal ions and the organic matter and the heavy metal resource recovery rate of the treatment method of the present application are much higher than those of the conventional physical and chemical processes.

[0054] As a preferred technical solution of the present application, during the acid leaching treatment, the volume ratio of the characteristic seed after the treatment to the acid is 1:1.

[0055] As a preferred technical solution of the present application, the treatment method further comprises adjusting the pH of the raffinate after the treatment to 7-7.5, so as to make the raffinate neutral.

[0056] As a preferred technical solution of the present application, the acid used in the acid leaching treatment is selected from sulfuric acid and / or nitric acid.

[0057] As a preferred technical solution of the present application, the pH regulator for the raffinate after the treatment is selected from sulfuric acid and / or nitric acid.

[0058] As a specific embodiment of the present application, the treatment method comprises the following steps:

[0059] (1) pH adjustment: adding an alkalinizing agent to the raffinate wastewater to adjust the pH of the wastewater to 6-7;

[0060] (2) Seed filling: placing characteristic seeds in a fluidized bed, the volume of the characteristic seeds being 20%-35% of the volume of the fluidized bed;

[0061] (3) Primary nucleation granulation: respectively feeding the raffinate and an alkalinizing agent solution into the fluidized bed, the hourly flow rate of the raffinate being 15-25 times the volume of the fluidized bed, the flow rate of the alkalinizing agent solution being 10-20% of the flow rate of the raffinate, and the concentration of the alkalinizing agent being 4000-6000 mg / L, to obtain a primary raffinate;

[0062] (4) pH adjustment: adding an acid to adjust the pH of the primary raffinate to 7-7.5;

[0063] (5) Secondary nucleation granulation: respectively feeding the primary raffinate and an alkalinizing agent solution into the fluidized bed, the hourly flow rate of the primary raffinate being 15-25 times the volume of the fluidized bed, the flow rate of the alkalinizing agent being 10-20% of the flow rate of the primary raffinate, and the concentration of the alkalinizing agent being 4000-6000 mg / L, to obtain a secondary raffinate;

[0064] (6) pH adjustment: adding an acid to adjust the pH of the secondary raffinate to 7-7.5;

[0065] (7) Tertiary nucleation granulation: respectively feeding the secondary raffinate and an alkalinizing agent solution into the fluidized bed, the hourly flow rate of the secondary raffinate being 15-25 times the volume of the fluidized bed, the flow rate of the alkalinizing agent being 10-20% of the flow rate of the secondary raffinate, and the concentration of the alkalinizing agent being 4000-6000 mg / L, to obtain a tertiary raffinate, wherein the content of heavy metals in the raffinate is less than 350 mg / L and the COD is greater than 300 mg / L;

[0066] (8) pH adjustment: adding an acid to adjust the pH of the tertiary raffinate to 7.5-8;

[0067] (9) Quaternary nucleation granulation: respectively feeding the tertiary raffinate and an alkalinizing agent solution into the fluidized bed, the hourly flow rate of the tertiary raffinate being 15-25 times the volume of the fluidized bed, the flow rate of the alkalinizing agent being 10-20% of the flow rate of the tertiary raffinate, and the concentration of the alkalinizing agent being 6000-8000 mg / L, to obtain a quaternary raffinate;

[0068] (10) pH adjustment: adjust the pH of the fourth-stage raffinate to 8 by adding acid;

[0069] (11) fifth-stage seed crystal granulation: introduce the fourth-stage raffinate and an alkalizing agent solution into a fluidized bed, respectively, the flow rate of the fourth-stage raffinate per hour is 15-25 times the volume of the fluidized bed, the flow rate of the alkalizing agent is 10-20% of the flow rate of the fourth-stage raffinate, and the concentration of the alkalizing agent is 8000-10000 mg / L, to obtain a fifth-stage raffinate;

[0070] (12) pH adjustment: adjust the pH of the fifth-stage raffinate to 8.5 by adding acid;

[0071] (13) sixth-stage seed crystal granulation: introduce the fifth-stage raffinate and an alkalizing agent solution into a fluidized bed, respectively, the flow rate of the fifth-stage raffinate per hour is 15-25 times the volume of the fluidized bed, the flow rate of the alkalizing agent is 10-20% of the flow rate of the fifth-stage raffinate, and the concentration of the alkalizing agent is 8000-10000 mg / L, to obtain a sixth-stage raffinate, wherein the content of heavy metals is less than 10 mg / L and the COD is less than 300 mg / L;

[0072] (14) pH adjustment: adjust the pH of the sixth-stage raffinate to 7-7.5 by adding acid;

[0073] (15) acid leaching seed crystal: recover and utilize the heavy metals loaded on the characteristic seed crystal by acid leaching the discharged characteristic seed crystal.

[0074] The technical scheme provided by the embodiments of the present application has the following advantages compared with the prior art:

[0075] 1. The treatment method provided by the present application is based on the granulation coagulation theory, and the characteristic seed crystal is used as a renewable resource for recycling, which can realize the simultaneous removal of organic matter and heavy metal ions in raffinate wastewater and resource recovery, and the final effluent has a COD of less than 300 mg / L, a heavy metal ion concentration of less than 10 mg / L, and a heavy metal recovery rate of more than 98%, and the process cost is effectively reduced.

[0076] 2. The treatment method provided by the present application has a short hydraulic retention time, low effluent turbidity, no sludge, and no secondary pollution. BRIEF DESCRIPTION OF DRAWINGS

[0077] The accompanying drawings, which are incorporated into and form part of the specification, illustrate embodiments consistent with the present application and, together with the specification, serve to explain the principles of the application.

[0078] In order to more clearly illustrate the technical schemes in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or the prior art description will be briefly introduced as follows. Obviously, other drawings can also be obtained by those skilled in the art without any creative effort.

[0079] Figure 1 A schematic diagram of the reaction mechanism of the treatment method of the hydrometallurgical raffinate of the present application;

[0080] Figure 2 A process flow chart of the treatment method of the hydrometallurgical raffinate described in Example 1 of the present application. DETAILED DESCRIPTION

[0081] In order to enable a more complete understanding of the above-mentioned objects, features and advantages of the present application, the scheme of the present application will be further described below. It should be noted that the embodiments of the present application and the features in the embodiments can be combined with each other without conflict.

[0082] In the following description, many specific details are set forth in order to provide a thorough understanding of the present application, but the present application can also be implemented in other ways different from those described herein; obviously, the embodiments in the description are only some of the embodiments of the present application, not all the embodiments.

[0083] Example 1

[0084] The present embodiment provides a treatment method of a hydrometallurgical raffinate, the properties of the raffinate are as follows: pH = 4.8-5.2, COD = 800-1000 mg / L, oil content is 280 mg / L, Co 2+ content is 828 mg / L, Ni 2+ content is 306 mg / L, and TDS is 102 g / L. The main components of COD are a small amount of dispersed oil, extractant P507, solvent oil, sulfonated kerosene and cobalt-nickel complex;

[0085] The process flow chart of the treatment method is shown in Figure 2 , and specifically comprises the following steps:

[0086] (1) pH adjustment: adding sodium hydroxide to the raffinate wastewater to adjust the pH of the raffinate wastewater to 6.5;

[0087] (2) Seed crystal filling: adding characteristic seed crystals to the upflowing fluidized bed, the addition amount is 25% of the volume of the fluidized bed, and the volume of the fluidized bed is 0.5 L;

[0088] (3) First-stage nucleation and granulation: passing the raffinate and the alkalinizing agent solution into the fluidized bed through the water pump and the medicine pump respectively, the flow rate of the raffinate is 13 L / h, the concentration of the alkalinizing agent is 5000 mg / L, the flow rate of the alkalinizing agent is 1.5 L / h, and the first-stage raffinate is obtained;

[0089] (4) pH readjustment: adding acid to readjust the pH of the first-stage raffinate to 7 through the acid pump;

[0090] (5) Secondary nucleation granulation: the first-stage raffinate and alkalizing agent solution were respectively fed into the fluidized bed by water pump and medicine pump, the first-stage raffinate flow rate was 13 L / h, the alkalizing agent concentration was 5000 mg / L, and the alkalizing agent flow rate was 1.5 L / h, to obtain the secondary-stage raffinate;

[0091] (6) pH adjustment: the pH of the secondary-stage raffinate was adjusted to 7.3 by adding acid through the acid pump;

[0092] (7) Tertiary nucleation granulation: the secondary-stage raffinate and alkalizing agent solution were respectively fed into the fluidized bed by water pump and medicine pump, the secondary-stage raffinate flow rate was 13 L / h, the alkalizing agent concentration was 5000 mg / L, and the alkalizing agent flow rate was 1.5 L / h, to obtain the tertiary-stage raffinate, at this time, the COD was 565 mg / L, the Co 2+ concentration was 264 mg / L, and the Ni 2+ concentration was 82 mg / L;

[0093] (8) pH adjustment: the pH of the tertiary-stage raffinate was adjusted to 7.5 by adding acid through the acid pump;

[0094] (9) Quaternary nucleation granulation: the tertiary-stage raffinate and alkalizing agent solution were respectively fed into the fluidized bed by water pump and medicine pump, the tertiary-stage raffinate flow rate was 13 L / h, the alkalizing agent concentration was 8000 mg / L, and the alkalizing agent flow rate was 1.5 L / h, to obtain the quaternary-stage raffinate;

[0095] (10) pH adjustment: the pH of the quaternary-stage raffinate was adjusted to 8 by adding acid through the acid pump;

[0096] (11) Quinary nucleation granulation: the quaternary-stage raffinate and alkalizing agent solution were respectively fed into the fluidized bed by water pump and medicine pump, the quaternary-stage raffinate flow rate was 13 L / h, the alkalizing agent concentration was 9000 mg / L, and the alkalizing agent flow rate was 1.5 L / h, to obtain the quinary-stage raffinate, at this time, the COD was 324 mg / L, the Co 2+ concentration was 31 mg / L, and the Ni 2+ concentration was 19 mg / L;

[0097] (12) pH adjustment: the pH of the quinary-stage raffinate was adjusted to 8.5 by adding acid through the acid pump;

[0098] (13) Sextuple nucleation granulation: the quinary-stage raffinate and alkalizing agent were respectively fed into the fluidized bed by water pump and medicine pump, the quinary-stage raffinate flow rate was 13 L / h, the alkalizing agent concentration was 10000 mg / L, and the alkalizing agent flow rate was 1.5 L / h, to obtain the sextuple-stage raffinate, at this time, the COD was 255 mg / L, the Co 2+ concentration was 6 mg / L, and the Ni 2+ concentration was 4 mg / L;

[0099] (14) pH adjustment: the pH of the sixth-stage raffinate is adjusted to 7-7.5 by adding acid to the sixth-stage raffinate with an acid pump to obtain the effluent;

[0100] (15) Acid leaching of seeds: the discharged characteristic seeds are subjected to acid leaching (volume ratio 1:1) with sulfuric acid to realize recycling of the heavy metals loaded on the seeds, Co 2+ The recovery rate reaches 99.3%, Ni 2+ The recovery rate reaches 98.7%.

[0101] Example 2

[0102] The present example provides a treatment method for a hydrometallurgical raffinate, the properties of the raffinate being the same as in Example 1, and the treatment method being the same as in Example 1.

[0103] The difference from Example 1 is that the fractionated raffinate obtained in the treatment method of the present example is not subjected to pH adjustment, but is directly subjected to the next-stage nucleation granulation step.

[0104] The COD in the sixth-stage raffinate is detected to be 485 mg / L, Co 2+ The concentration is 94 mg / L, Ni 2+ The concentration is 61 mg / L.

[0105] Comparative Example 1

[0106] The present comparative example provides a treatment method for a hydrometallurgical raffinate, the properties of the raffinate being the same as in Example 1, and the treatment method being the same as in Example 1.

[0107] The difference from Example 1 is that the treatment method of the present comparative example does not add characteristic seeds.

[0108] The COD in the sixth-stage raffinate is detected to be 684 mg / L, Co 2+ The concentration is 148 mg / L, Ni 2+ The concentration is 101 mg / L.

[0109] Comparative Example 2

[0110] The present comparative example provides a treatment method for a hydrometallurgical raffinate, the properties of the raffinate being the same as in Example 1, and the treatment method being the same as in Example 1.

[0111] The difference from Example 1 is that the treatment method of the present comparative example does not add the alkali agent sodium hydroxide.

[0112] The COD in the sixth-stage raffinate is detected to be 792 mg / L, Co 2+ The concentration is 754 mg / L, Ni 2+ The concentration is 276 mg / L.

[0113] From the examples 1-2 and the comparative examples 1-2, it can be seen that the treatment method provided in the present application can effectively remove the organic matter and heavy metal ions in the hydrometallurgical raffinate, and the COD of the effluent is less than 300 mg / L, the concentration of heavy metal ions is less than 10 mg / L, and the recovery rate of heavy metals is more than 98%.

[0114] It should be noted that, in this document, relational terms such as "first" and "second", and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises... a" does not, without more constraints, exclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0115] The above description is merely that of a specific implementation of the present application, and enables those skilled in the art to understand or implement the present application. Various modifications to the embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Accordingly, the present application is not intended to be limited to the embodiments described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A method for treating hydrometallurgical extraction residue, characterized in that, The processing method includes the following steps: (1) Place the characteristic seed crystals in a fluidized bed; (2) The raffinate is fed into the fluidized bed for a fractional coprecipitation reaction. After the reaction, the fractional raffinate is obtained. The pH value of the fractional raffinate is adjusted and fed into the fluidized bed again for the next fractional coprecipitation reaction. In the aforementioned graded coprecipitation reaction, each stage of the coprecipitation reaction is carried out in the presence of an alkalizing agent. (3) Repeat step (2) until the heavy metal content in the fractionated raffinate is less than 10 mg / L and the COD is less than 300 mg / L, at which point the treatment is complete; The processing method also includes acid leaching the processed characteristic seed crystals; In the fractional coprecipitation reaction, the concentration of the alkalizing agent is 4000-10000 mg / L; when the heavy metal content in the fractional raffinate is greater than 350 mg / L, the concentration of the alkalizing agent is 4000-6000 mg / L; when the heavy metal content in the fractional raffinate is less than 350 mg / L, the concentration of the alkalizing agent is 6000-10000 mg / L; the concentration of the alkalizing agent increases progressively. In step (2), the pH value of the fractionated raffinate is adjusted to 7-8.5; when the heavy metal content in the fractionated raffinate is greater than 350 mg / L, the pH value of the fractionated raffinate is adjusted to 7-7.5; when the heavy metal content in the fractionated raffinate is less than 350 mg / L, the pH value of the fractionated raffinate is adjusted to 7.5-8.5; the pH value of the fractionated raffinate is gradually increased.

2. The processing method according to claim 1, characterized in that, The average grain size of the characteristic seed crystals is 0.2-0.3 mm; And / or, the volume of the characteristic seed crystal is 20-35% of the volume of the fluidized bed; And / or, the hourly flow rate of the raffinate is 15-25 times the volume of the fluidized bed; And / or, the hourly flow rate of the fractionated raffinate is 15-25 times the volume of the fluidized bed.

3. The processing method according to claim 2, characterized in that, The alkalizing agent is introduced into the fluidized bed in the form of an alkalizing agent solution.

4. The processing method according to claim 3, characterized in that, The flow rate of the alkalizing agent solution is 10-20% of the flow rate of the raffinate in the corresponding fractional coprecipitation reaction.

5. The processing method according to claim 1, characterized in that, The fluidized bed in step (1) is an upward flow fluidized bed; And / or, the pH of the raffinate in step (2) is 6-7; And / or, the alkalizing agent is selected from sodium hydroxide and / or sodium carbonate; And / or, the reaction temperature of each of the fractional coprecipitation reactions is independently 5-35°C; And / or, the pH adjuster of the fractionated raffinate is selected from sulfuric acid and / or nitric acid.

6. The processing method according to claim 1, characterized in that, The volume ratio of the characteristic seed crystals to the acid after the treatment is 1:1; And / or, the treatment method further includes adjusting the pH of the raffinate after treatment to 7-7.

5.

7. The processing method according to claim 6, characterized in that, The acid used in the acid leaching treatment is selected from sulfuric acid and / or nitric acid; And / or, the pH adjuster of the raffinate after the treatment is selected from sulfuric acid and / or nitric acid.

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