CN111424174A

CN111424174A - Method for removing surfactant in metal raw material leaching solution, purification device and application

Info

Publication number: CN111424174A
Application number: CN201910323649.XA
Authority: CN
Inventors: 谢勇冰; 曹宏斌; 徐双
Original assignee: Institute of Process Engineering of CAS
Current assignee: Institute of Process Engineering of CAS
Priority date: 2019-04-22
Filing date: 2019-04-22
Publication date: 2020-07-17
Anticipated expiration: 2039-04-22
Also published as: CN111424174B

Abstract

The invention relates to a method for removing a surfactant in a metal raw material leachate, a purification device and application, wherein the method comprises the following steps: carrying out advanced oxidation treatment on the metal raw material leachate to obtain purified metal raw material leachate, wherein the purification device is used in the method for removing the surfactant in the metal raw material leachate, the purification device comprises an advanced oxidation reactor 1, a metal raw material leachate adding device 2, an exhaust gas discharging device 7, a purified liquid discharging device 3, at least one ozone adding device 5 and at least one aeration device 6, the aeration device and the ozone adding device are connected through pipelines, and the method is used in the metallurgical industry. The method can effectively remove the surfactant, reduce the loss of metal raw materials and avoid the waste of the leaching agent.

Description

Method for removing surfactant in metal raw material leaching solution, purification device and application

Technical Field

The invention relates to the technical field of metallurgy, in particular to a method for removing a surfactant in a metal raw material leaching solution, a purification device and application.

Background

Scheelite, mixed wolframite and scheelite ore, tungsten fine mud, artificial scheelite, low-grade tungsten and molybdenum mixed ore, zinc oxide, metal-containing catalyst waste and other metal raw materials have become the main raw materials of the metal industry. In the process of processing the raw materials, a surfactant-based beneficiation reagent is often added, and the presence of the surfactant has various adverse effects on the subsequent processes. For example, in the process of preparing sodium tungstate solution by leaching tungsten mineral raw material containing surfactant, the surfactant can enter the sodium tungstate solution, and in the process of producing ammonium paratungstate by adopting extraction process (including acid extraction process and alkaline extraction process), the surfactant in the sodium tungstate solution can pollute the extractant, cause the loss of the extractant, or cause difficult phase separation during extraction, generate a third phase, thereby damaging the normal operation of the production line and even causing the paralysis of the production line.

CN106011504B discloses a method for decomposing scheelite, comprising the following steps: the method comprises the following steps: grinding scheelite to make its granularity smaller than 325 mesh; step two: mixing the ground scheelite with sodium silicate to obtain a mixture; step three: placing the mixture in a high-temperature furnace for roasting to obtain a roasted product; step four: grinding the above roasted material, leaching with water, filtering, and oven drying to decompose scheelite and extract tungsten.

CN107287445A discloses a method for vacuum extraction of metallic zinc from wurtzite. Firstly, oxidizing and roasting the sphalerite under the air atmosphere and at the temperature of 1050-1080 ℃ to generate calcine; and uniformly mixing the calcine and the metallic iron, distilling at the constant pressure of 10-30 Pa and the temperature of 1050-1200 ℃ for 20-60 min to obtain metallic zinc steam, and condensing to obtain metallic zinc and iron slag residues. Firstly, oxidizing and roasting the sphalerite, and converting zinc and iron in the ore from sulfides into oxides; then mixing the roasted product with metal iron, putting the mixture into a vacuum furnace, and condensing zinc in a condensation zone in the form of metal steam under certain temperature and pressure conditions to obtain metal zinc; the iron remains in the residue and is used as iron concentrate, and the produced iron can be recycled as a reducing agent.

CN102730748B discloses a method for preparing lead chloride and zinc sulfate by using medium and low grade zinc oxide ore and zinc oxide and lead oxide paragenic ore, which comprises the following steps: (1) crushing zinc ore, grinding, mixing with ammonium sulfate and roasting; (2) dissolving out the roasted clinker, precipitating iron and aluminum in the obtained filtrate, and further separating lead from the zinc extraction slag; (3) evaporating the zinc sulfate solution obtained after iron and aluminum precipitation to be concentrated for electrolysis; (4) leaching the zinc extraction residue with NaCl solution, concentrating the filtrate after leaching, cooling and crystallizing to separate out PbCl₂The crystal and NaCl solution are returned to the leaching process, so that the cyclic utilization is realized.

In the above prior art, in order to remove the surfactant in the metal raw material, the metal raw material is treated by an oxidizing roasting method, that is, the metal raw material is oxidized at a high temperature for a certain time in an oxidizing atmosphere, so as to ensure that the leached metal salt solution does not contain the surfactant. The prior art has the defects that the high temperature in the roasting process results in high energy consumption, high labor intensity and poor working environment, and generates a large amount of roasting smoke which is difficult to treat, thereby causing huge environmental risk. Particularly, a part of metal raw materials are low in yield and high in price, the metal content difference between batches of the metal raw materials is large, and the metal raw materials are mixed randomly in the roasting process, so that the smelting grade of the metal raw materials is unclear during leaching, and the subsequent operation processes such as batching and leaching are seriously influenced. In order to ensure the leaching rate of the metal raw material, the leaching agent is usually added in excess in production, so that the leaching agent is wasted. In addition, the roasting process also causes a certain proportion of metal loss, for example, the tungsten loss rate caused by the roasting process of the tungsten mineral raw material in the prior art is about 2.5%, which causes great resource waste and poor economical efficiency.

Therefore, there is a need in the art to develop a new method for removing a surfactant from a metal raw material leachate, which can effectively remove the surfactant, reduce the loss of the metal raw material, avoid the waste of the leaching agent, and has the advantages of low energy consumption, low labor intensity, good working environment, no release of polluted gas, and the like.

Disclosure of Invention

In view of the deficiencies of the prior art, it is an object of the present invention to provide a method for removing a surfactant from a leachate of a metal feedstock, the method comprising the steps of: and carrying out advanced oxidation treatment on the metal raw material leachate to obtain purified metal raw material leachate.

"advanced oxidation" refers to a process of oxidative degradation of organic substances that are difficult to be oxidized by common oxidants by generating hydroxyl radicals.

The invention carries out advanced oxidation treatment on the metal raw material leachate, and oxidizes the surfactant through hydroxyl free radicals generated in the process to achieve the purpose of removing the surfactant in the metal raw material. Compared with the method for directly treating the metal raw material to remove the surfactant, the method has the advantages that the surfactant is removed after the metal is leached, the surfactant is uniformly dispersed in the leaching solution, and the higher oxidation treatment is carried out, so that the better removal effect can be achieved. Meanwhile, the loss of metal raw materials can be reduced, the waste of leaching agents is avoided, and the method has the advantages of low energy consumption, low labor intensity, good operation environment, no pollution gas release and the like.

Preferably, the metal feedstock leachate containing sodium carbonate is subjected to freeze crystallisation prior to the advanced oxidation treatment.

In the preferred scheme of the invention, before the advanced oxidation step, a freezing crystallization step is carried out, and as most of leaching agents of metal raw materials are sodium carbonate, a part of carbonate ions can remain in the leaching solution, and the carbonate ions have a certain inhibition effect on the advanced oxidation reaction.

Preferably, the temperature of the freeze crystallization is-10 to 10 ℃, for example, -9 ℃, -8 ℃, -7 ℃, -6 ℃, -5 ℃, -4 ℃, -3 ℃, -2 ℃, -1 ℃, 0 ℃, 1 ℃, 2 ℃, 3 ℃, 4 ℃, 5 ℃, 6 ℃, 7 ℃, 8 ℃ or 9 ℃, preferably-7 to 5 ℃.

Preferably, the freezing crystallization specifically comprises the following steps: and (3) freezing the metal raw material leaching solution to-10 ℃, separating out sodium carbonate crystals, filtering, and collecting the filtrate.

Preferably, the oxidizing agent of the advanced oxidation treatment includes any one or a combination of at least two of ozone, hydrogen peroxide, a persulfate, and a monopersulfate.

Preferably, the oxidizing agent comprises ozone and/or hydrogen peroxide, preferably ozone and hydrogen peroxide.

The ozone and the hydrogen peroxide are used together to generate more hydroxyl radicals, namely, the hydroxyl radicals have higher free radical generation rate, and the surfactant can be removed more thoroughly.

Preferably, the mass ratio of the ozone to the TOC corresponding to the surfactant in the metal raw material leachate is 4-10: 1, such as 4:1, 5:1, 6:1, 7:1, 8:1, 9:1, 10:1, and the like.

TOC is total organic carbon (herein abbreviated as TOC), and represents the total organic carbon corresponding to the surfactant in the present invention.

Preferably, the temperature of the advanced oxidation treatment is 0 to 100 ℃, for example, 2 ℃, 5 ℃, 10 ℃, 15 ℃, 20 ℃, 25 ℃, 30 ℃, 35 ℃, 40 ℃, 45 ℃, 50 ℃, 55 ℃, 60 ℃, 65 ℃, 70 ℃, 75 ℃, 80 ℃, 85 ℃, 90 ℃, 95 ℃ or 98 ℃, preferably 25 to 75 ℃, and more preferably 30 to 50 ℃.

Preferably, the time of the advanced oxidation treatment is 0.25 to 12 hours, such as 0.3 hour, 0.5 hour, 1 hour, 2 hours, 3 hours, 4 hours, 5 hours, 6 hours, 7 hours, 8 hours, 9 hours, 10 hours or 11 hours, and the like, and preferably 0.5 to 3 hours.

Preferably, the advanced oxidation treatment is performed under the action of an external energy field.

In a preferable scheme, an external energy field is added to promote the oxidizing agent to form hydroxyl radicals, so that the surfactant is oxidized to a greater extent, and the removal effect is better.

Preferably, the applied energy field comprises ultraviolet light and/or ultrasound.

Preferably, the advanced oxidation treatment is carried out under the action of a catalyst.

Preferably, the catalyst is a heterogeneous catalyst, preferably any one or a combination of at least two of activated carbon, titania, transition metal supported titania and transition metal supported activated carbon.

Preferably, the metal feedstock comprises a mineral feedstock.

Preferably, the mineral raw material comprises any one or a combination of at least two of a tungsten mineral raw material, a zinc mineral raw material, a copper mineral raw material and an iron mineral raw material, preferably a tungsten mineral raw material.

Preferably, the metal feedstock leach solution comprises a sodium tungstate leach solution.

Preferably, the tungsten mineral feedstock leachate is obtained by leaching with a sodium carbonate solution.

Preferably, the pH of the metal raw material leachate is 7.5 to 14, such as 8, 9, 10, 11, 12 or 13, and preferably 8.5 to 10.5.

The pH value of the metal raw material leachate is preferably 7.5-14, because a plurality of metal mineral phases can be separated by alkaline solution leaching, and an external oxidant is easy to generate strong oxidizing free radicals in alkaline solution, such as ozone, sodium persulfate, ozone and hydrogen peroxide, ozone and sodium persulfate and other oxidants or combination of oxidants, so that the surfactant is efficiently removed, and the effect is optimal when the pH value is 8.5-10.5.

Preferably, the method specifically comprises the following steps:

adding an oxidant into the metal raw material leachate with the pH value of 7.5-14, and performing advanced oxidation treatment for 0.25-12 h at the temperature of 0-100 ℃ under the action of an external energy field and a catalyst to obtain the purified metal raw material leachate.

The second object of the present invention is to provide an apparatus for carrying out the method of the first object, wherein the purification apparatus comprises a high-stage oxidation reactor 1, a metal raw material leachate adding apparatus 2 and an exhaust gas discharging apparatus 7 are provided at an upper portion of the high-stage oxidation reactor, a purified liquid discharging apparatus 3 and at least one ozone adding apparatus 5 are provided at a lower portion of the high-stage oxidation reactor, at least one aeration apparatus 6 is provided inside the high-stage oxidation reactor, and the aeration apparatus and the ozone adding apparatus are connected by a pipeline.

The purification apparatus of the present invention is designed to achieve the method described as one of the objects of the present invention.

Preferably, two or three aeration devices are provided inside the advanced oxidation reactor.

Preferably, an oxidant adding device 4 is arranged at the upper part of the advanced oxidation reactor.

Preferably, a catalyst bed is provided inside the advanced oxidation reactor. Preferably, at least one external energy field generating device is arranged inside the advanced oxidation reactor.

Preferably, the external energy field generating device comprises an ultraviolet light generating device and an ultrasonic generating device.

Preferably, the ultraviolet light generating device is arranged at the top of the advanced oxidation reactor.

Preferably, the ultrasound generating means comprises an ultrasound probe.

Preferably, the ultrasonic generator is arranged at the bottom of the advanced oxidation reactor.

It is a further object of the invention to provide the use of the method according to one of the objects for the metallurgical industry.

Preferably, the method is used for tungsten mineral raw material smelting.

Compared with the prior art, the invention has the following beneficial effects:

the invention carries out advanced oxidation treatment on the metal raw material leachate, and oxidizes the surfactant by hydroxyl free radicals generated by the oxidant. Compared with the method for directly removing the surfactant in the metal raw material, the method selects the treatment after the metal leaching, and the surfactant is uniformly dispersed in the leaching solution, so that a better oxidation removal effect can be achieved. Meanwhile, the loss of metal raw materials can be reduced, the waste of leaching agents is avoided, and the method has the advantages of low energy consumption, low labor intensity, good operation environment, no pollution gas release and the like.

Drawings

Fig. 1 is a schematic structural diagram of a purification apparatus according to an embodiment of the present invention.

Wherein: 1-advanced oxidation reactor; 2-adding the metal raw material leachate into a device; 3-purified liquid discharge means; 4-an oxidant addition device; 5-an ozone adding device; 6-an aeration device; 7-an exhaust gas discharge device; 8-external energy field generating device.

FIG. 2 is a flow diagram of a process for removing a surfactant from a leachate of a metal feedstock according to one embodiment of the present invention.

Detailed Description

For the purpose of facilitating an understanding of the present invention, the present invention will now be described by way of examples. It should be understood by those skilled in the art that the examples are only for the understanding of the present invention and should not be construed as the specific limitations of the present invention.

The following examples of the method for removing the surfactant from the leachate of the metal raw material were carried out according to the flow shown in fig. 2 and implemented by using the apparatus shown in fig. 1.

Example 1

The embodiment provides a method for removing a surfactant in a metal raw material leachate, which comprises the following specific steps:

(1) freezing and crystallizing sodium tungstate leach liquor containing a surfactant at 0 ℃, filtering after crystal precipitation, collecting filtrate, taking 350m L filtrate (the concentration of tungsten is 81.4 g/L, the concentration of Total Organic Carbon (TOC) corresponding to the surfactant is 73.5 mg/L, the pH is 11.0), adding a sulfuric acid solution to adjust the pH to 10.0, adding the sodium tungstate leach liquor with the adjusted pH value into a high-grade oxidation reactor 1 through a metal raw material leach liquor adding device 2, wherein the reactor 1 comprises an active carbon catalyst bed layer, introducing ozone into the high-grade oxidation reactor 1 through an ozone adding device 5, uniformly distributing the ozone into the sodium tungstate through an aeration device 6, simultaneously adding 30% hydrogen peroxide through an oxidant adding device 4 at the speed of 1m L/h, fully mixing the sodium tungstate leach liquor, starting an ultraviolet light generating device to react for 3h, and adding 4 times of the total amount of the ozone of the TOC to obtain purified sodium tungstate leach liquor (primary purified sodium tungstate leach liquor).

(2) Adding a magnesium sulfate solution into the primary purified liquid obtained in the step (1) to purify and remove impurity elements such as silicon, phosphorus, arsenic, fluorine and the like, filtering to obtain secondary purified liquid, transferring the secondary purified liquid into a sulfuration acid-regulating molybdenum-removing device, adding a sodium sulfide solution into the secondary purified liquid to sulfuration acid-regulating molybdenum-removing to obtain a refined sodium tungstate solution, extracting the refined sodium tungstate solution by taking N235 (trioctanoamino ammonium) as an extracting agent in an extraction and back-extraction device to obtain a loaded organic phase, washing the loaded organic phase twice by using pure water, performing back extraction on the loaded organic phase by taking ammonia water as a back-extraction agent to obtain an ammonium tungstate solution, and evaporating and crystallizing the ammonium tungstate solution to obtain an ammonium paratungstate product.

Example 2

The difference from example 1 is that the tungsten concentration in the filtrate was 82.4 g/L at 75.6 mg/L and the pH was 10.5, and no freeze crystallization step was performed.

Example 3

The difference from example 1 is that the tungsten concentration in the filtrate is 81.9 g/L, 74.5 mg/L, the pH is 11.0, and 30% hydrogen peroxide is replaced by the same amount of persulfate.

Example 4

The difference from example 1 is that the tungsten concentration in the filtrate was 82.1 g/L at a concentration of 72.0 mg/L, the pH was 10.7, and ozone was not introduced.

Example 5

The difference from example 1 is that the tungsten concentration in the filtrate was 81.3 g/L at 71.4 mg/L, the pH was 11.3, and the temperature of the higher oxidation in step (1) was 30 ℃.

Example 6

The difference from example 1 is that the tungsten concentration in the filtrate was 82.3 g/L at a concentration of 74.0 mg/L, the pH was 11.7, and the temperature of the higher oxidation in step (1) was 50 ℃.

Example 7

The difference from example 1 is that the tungsten concentration in the filtrate was 80.4 g/L at a concentration of 75.1 mg/L, the pH was 10.7, and the temperature of the higher oxidation in step (1) was 25 ℃.

Example 8

The difference from example 1 is that the tungsten concentration in the filtrate was 80.9 g/L at 73.1 mg/L, the pH was 10.9, and the temperature of the higher oxidation in step (1) was 75 ℃.

Example 9

The difference from example 1 is that the tungsten concentration in the filtrate was 82.0 g/L at 74.8 mg/L, the pH was 11.1, and the temperature of the higher oxidation in step (1) was 0 ℃.

Example 10

The difference from example 1 is that the tungsten concentration in the filtrate was 82.1 g/L at 76.0 mg/L, the pH was 11.2, and the temperature of the higher oxidation in step (1) was 100 ℃.

Example 11

The difference from example 1 is that the tungsten concentration in the filtrate was 81.6 g/L at 73.7 mg/L, the pH was 10.7, and the pH was adjusted to 8.5.

Example 12

The difference from example 1 is that the tungsten concentration in the filtrate was 81.0 g/L, the concentration was 72.5 mg/L, the pH was 10.2, and in step (1), the sulfuric acid solution was replaced with a sodium hydroxide solution, and the pH was adjusted to 10.5.

Example 13

The difference from example 1 is that the tungsten concentration in the filtrate was 80.9 g/L at 73.9 mg/L and the pH was 10.5, and in step (1), the pH was adjusted to 7.5.

Example 14

The difference from example 1 is that the tungsten concentration in the filtrate was 83.8 g/L, the concentration was 74.0 mg/L, the pH was 10.6, and in step (1), the sulfuric acid solution was replaced with a sodium hydroxide solution, and the pH was adjusted to 14.0.

Example 15

The difference from example 1 is that the tungsten concentration in the filtrate was 83.7 g/L, 73.1 mg/L, and the pH was 10.5, and in step (1), a sulfuric acid solution was added to adjust the pH to 6.5.

Example 16

(1) freezing and crystallizing sodium tungstate leach liquor containing a surfactant at-10 ℃, filtering after crystal precipitation, collecting filtrate, taking 350m L filtrate (the concentration of tungsten is 82.1 g/L is 76.0 mg/L, the pH is 10.6), adding a sulfuric acid solution to adjust the pH, adjusting the pH to 10.0, adding the sodium tungstate leach liquor with the adjusted pH value into a high-grade oxidation reactor 1 through a metal raw material leach liquor adding device 2, introducing ozone (the total amount of the added ozone is 5 times of the mass of TOC) into the high-grade oxidation reactor 1 through an ozone adding device 5, uniformly distributing the ozone in the sodium tungstate leach liquor through an aeration device 6, simultaneously adding 30% hydrogen peroxide through an oxidant adding device 4 at the speed of 1m L/h, fully mixing the sodium tungstate leach liquor with a high-grade oxidant and a catalyst, setting the temperature to be 35 ℃, starting an ultrasonic generator, and reacting the sodium tungstate leach liquor for 0.25h to obtain purified sodium tungstate (primary purification liquor).

(2) Adding a magnesium sulfate solution into the primary purified liquid obtained in the step (1) to purify and remove impurity elements such as silicon, phosphorus, arsenic, fluorine and the like, filtering to obtain secondary purified liquid, transferring the secondary purified liquid into a sulfuration acid-regulating molybdenum-removing device, adding a sodium sulfide solution into the secondary purified liquid to sulfuration acid-regulating molybdenum-removing to obtain a refined sodium tungstate solution, extracting the refined sodium tungstate solution by taking N235 as an extracting agent in an extraction and back-extraction device to obtain a loaded organic phase, washing the loaded organic phase twice by using pure water, back-extracting the loaded organic phase by taking ammonia water as a back-extracting agent to obtain an ammonium tungstate solution, and evaporating and crystallizing the ammonium tungstate solution to obtain an ammonium paratungstate product.

Example 17

(1) freezing and crystallizing sodium tungstate leach liquor containing a surfactant at 10 ℃, filtering after crystal precipitation, collecting filtrate, taking 350m L filtrate (the concentration of tungsten is 80.9 g/L is 74.8 mg/L, the pH is 11.1), adding a sulfuric acid solution to adjust the pH, adjusting the pH to 10.0, adding the adjusted pH sodium tungstate leach liquor into a high-grade oxidation reactor 1 through a metal raw material leach liquor adding device 2, introducing ozone into the high-grade oxidation reactor 1 through an ozone adding device 5, uniformly distributing the ozone in the sodium tungstate leach liquor through an aeration device 6, simultaneously adding 30% hydrogen peroxide through an oxidant adding device 4 at the speed of 1m L/h, fully mixing the sodium tungstate leach liquor with a high-grade oxidant and a catalyst, setting the temperature to be 35 ℃, starting an ultraviolet light generating device, reacting for 12h, and adding 10 times of total TOC of the ozone to obtain purified sodium tungstate leach liquor (primary purification liquor).

Example 18

The difference from example 1 is that the tungsten concentration in the filtrate was 81.4 g/L, the concentration was 76.6 mg/L, the pH was 10.3, and the total amount of ozone added was 8 times the amount of surfactant corresponding to the TOC mass.

Example 19

The difference from example 1 is that the tungsten concentration in the filtrate was 82.4 g/L at 77.1 mg/L, the pH was 10.3, and the total amount of ozone added was 10 times the amount of surfactant in terms of TOC.

Example 20

The difference from example 1 is that the tungsten concentration in the filtrate was 81.6 g/L, the concentration was 71.6 mg/L, the pH was 10.3, and the total amount of ozone added was 3 times the amount of surfactant corresponding to the TOC mass.

Example 21

The difference from example 1 is that the tungsten concentration in the filtrate was 80.9 g/L, the concentration was 76.2 mg/L, the pH was 10.3, and the total amount of ozone added was 11 times the amount of surfactant in terms of TOC mass.

Comparative example 1

(1) Freezing and crystallizing sodium tungstate leaching solution containing surfactant at 0 deg.C, precipitating crystal, filtering, collecting filtrate, and collecting 350m L filtrate (tungsten concentration of 82.4 g/L concentration of 71.5 mg/L, pH of 10.5).

(2) Adding a magnesium sulfate solution into the filtrate obtained in the step (1) to purify and remove impurity elements such as silicon, phosphorus, arsenic, fluorine and the like, filtering to obtain a secondary purified solution, transferring the secondary purified solution into a sulfuration acid-regulating molybdenum-removing device, adding a sodium sulfide solution into the secondary purified solution to sulfuration acid-regulating molybdenum-removing to obtain a refined sodium tungstate solution, extracting the refined sodium tungstate solution by using N235 as an extracting agent in an extraction and back-extraction device to obtain a loaded organic phase, washing the loaded organic phase twice by using pure water, and back-extracting the loaded organic phase by using ammonia water as a back-extracting agent to obtain an ammonium tungstate solution, and evaporating and crystallizing the ammonium tungstate solution to obtain an ammonium paratungstate product.

Comparative example 2

The same batch of scheelite is divided into two parts, the first part is mixed with a sodium carbonate solution and is leached for 3 hours at 190 ℃ to obtain a sodium tungstate leaching solution before purification (the concentration of tungsten is 81.0 g/L is 76.4 mg/L, the pH is 10.1), the second part is roasted for 1.5 hours at 750 ℃, the roasted scheelite is mixed with the sodium carbonate solution and is leached for 3 hours at 190 ℃ to obtain the purified sodium tungstate leaching solution.

Effect testing

(1) The TOC concentration of the sodium tungstate leach solutions before/after purification in examples and comparative examples was measured using a total organic carbon analyzer (instrument model: TOC-VCpH, manufacturer: shimadzu corporation), and the results are shown in table 1, where TOC removal rate is (TOC concentration before purification-TOC concentration after purification)/TOC concentration before purification.

(2) Taking example 1 as an example, the content of the main impurity elements in the obtained sodium paratungstate was measured by using an inductively coupled-plasma emission spectrometer (instrument model: Optima 5300DV, manufacturer: perkin elmer, usa), and the results are shown in table 2.

TABLE 1 TOC removal Effect of different treatment Processes

As can be seen from Table 1, the reduction amount of TOC in the examples is 46.2-95.1%, and the content of the surfactant in the leachate is greatly reduced after purification treatment under the optimized conditions; compared with the comparative example 1, the advanced oxidation is not carried out, and the reduction of TOC is only 28.3 percent, namely, a large amount of surfactant still remains in the leachate after the purification treatment; the TOC reduction in comparative example 2 was 96.2%, but the calcination method used had disadvantages such as high calcination temperature, high energy consumption, high labor intensity, poor working environment, and generation of a large amount of polluting fumes, causing environmental pollution, especially loss of metal raw materials. The results prove that the method provided by the invention can effectively remove the surfactant in the metal raw material leachate. Compared with the surfactant for removing the metal raw material by direct oxidation, the method selects to remove the surfactant after the metal is leached, so that the surfactant is uniformly dispersed in the leaching solution to achieve better removal effect, and the residual small amount of organic matters do not influence the subsequent operation. Meanwhile, the loss of metal raw materials can be reduced, the waste of leaching agents can be avoided, and the method has the advantages of low energy consumption, low labor intensity, good operation environment, no pollution gas release and the like.

Comparing examples 1 and 2, it can be seen that the freezing and crystallizing step (example 1) is performed before the advanced oxidation step, the surfactant removal is more thorough, because most of the leaching agents of the metal raw materials are sodium carbonate, so that a part of carbonate ions in the leachate is remained, and the carbonate ions have a certain inhibiting effect on the advanced oxidation reaction.

It is understood from comparative examples 1, 3 and 4 that when ozone and hydrogen peroxide are selected as the oxidizing agent for the advanced oxidation (example 1), a better effect of removing the surfactant can be achieved, and the effect is deteriorated in the absence of either one (examples 3 and 4), because the two oxidizing agents, ozone and hydrogen peroxide, act together to have a higher hydroxyl radical generation rate and more thoroughly remove the surfactant.

As is clear from comparison of examples 1 and 5 to 10, the removal of the surfactant was more complete when the temperature of the advanced oxidation was 25 to 75 ℃ (examples 1 and 5 to 8), particularly 30 to 50 ℃ (examples 1, 5 and 6).

As is clear from comparison of examples 1 and 11 to 15, the metal raw material leachate has a pH of 7.5 to 14 (examples 1 and 11 to 14), particularly 8.5 to 10.5 (examples 1, 11 and 12), and the effect is more excellent.

In comparison with examples 1 and 18 to 21, it can be seen that when the mass ratio of the ozone to the TOC corresponding to the surfactant in the metal raw material leachate is 4 to 10:1, the surfactant removal effect is the best, and further, the increase of the amount of ozone is not high, and the cost is increased.

TABLE 2 content of impurity elements in ammonium paratungstate product

Element(s)	Al	As	Bi	Ca	Cd	Co	Cr	Cu	Fe
										Content (ppm)	2	6	0.5	6	5	3	2	0.5	5
Element(s)	Mn	Mg	Ni	Pb	Sb	Si	Sn	Ti	V
										Content (ppm)	2	2	3	0.5	2	8	0.5	3	2

As can be seen from table 2, the quality of the ammonium paratungstate product obtained in example 1 meets the requirement of the ammonium paratungstate product at the APT-0 level in the national standard (GBT10116-2007) of the ammonium paratungstate product, which indicates that the method for removing the surfactant from the metal raw material leachate provided by the invention effectively removes the surfactant, and solves the problem that the extraction effect is affected by the pollution of the surfactant to the extractant in the extraction process.

The applicant states that the present invention is illustrated by the above examples to show the detailed process equipment and process flow of the present invention, but the present invention is not limited to the above detailed process equipment and process flow, i.e. it does not mean that the present invention must rely on the above detailed process equipment and process flow to be implemented. It should be understood by those skilled in the art that any modification of the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific modes, etc., are within the scope and disclosure of the present invention.

Claims

1. A method for removing a surfactant from a metal feedstock leachate, the method comprising the steps of: and carrying out advanced oxidation treatment on the metal raw material leachate to obtain purified metal raw material leachate.

2. The process according to claim 1, wherein the metal feedstock leachate is subjected to freeze crystallization prior to the advanced oxidation treatment;

preferably, the temperature of the frozen crystal is-10 ℃, preferably-7-5 ℃;

preferably, the freezing crystallization specifically comprises the following steps: and (3) freezing the metal raw material leaching solution to-10 ℃, separating out crystals, filtering, and collecting filtrate.

3. The method according to claim 1 or 2, wherein the oxidizing agent of the advanced oxidation treatment comprises any one or a combination of at least two of ozone, hydrogen peroxide, a persulfate, and a monopersulfate;

preferably, the oxidizing agent comprises ozone and/or hydrogen peroxide, preferably ozone and hydrogen peroxide;

preferably, the mass ratio of the ozone to the TOC corresponding to the surfactant in the metal raw material leachate is 4-10: 1;

preferably, the temperature of the advanced oxidation treatment is 0-100 ℃, preferably 25-75 ℃, and further preferably 30-50 ℃;

preferably, the time of the advanced oxidation treatment is 0.25-12 h, preferably 0.5-3 h.

4. The method according to any one of claims 1 to 3, wherein the advanced oxidation treatment is carried out under the action of an external energy field;

5. The method according to any one of claims 1 to 4, wherein the advanced oxidation treatment is carried out under the action of a catalyst;

6. The method according to any one of claims 1 to 5, wherein the metal feedstock comprises a mineral feedstock;

preferably, the mineral raw material comprises any one or at least two of tungsten mineral raw material, zinc mineral raw material, copper mineral raw material and iron mineral raw material, preferably tungsten mineral raw material;

preferably, the metal feedstock leach solution comprises a sodium tungstate leach solution;

preferably, the tungsten mineral raw material leachate is obtained by leaching with a sodium carbonate solution;

preferably, the pH value of the metal raw material leaching solution is 7.5-14, and preferably 8.5-10.5.

7. The method according to any one of claims 1 to 6, characterized in that the method comprises in particular the steps of:

8. A purification apparatus for implementing the method according to any one of claims 1 to 7, wherein the purification apparatus comprises a high-stage oxidation reactor (1), a metal raw material leachate adding apparatus (2) and an exhaust gas discharging apparatus (7) are provided in an upper portion of the high-stage oxidation reactor, a purified liquid discharging apparatus (3) and at least one ozone adding apparatus (5) are provided in a lower portion of the high-stage oxidation reactor, and at least one aeration apparatus (6) is provided in the high-stage oxidation reactor, and the aeration apparatus and the ozone adding apparatus are connected by a pipeline.

9. The purification apparatus according to claim 8, wherein two or three aeration devices are provided inside the advanced oxidation reactor;

preferably, an oxidant adding device (4) is arranged at the upper part of the advanced oxidation reactor;

preferably, a catalyst bed layer is arranged inside the advanced oxidation reactor;

preferably, at least one external energy field generating device is arranged inside the advanced oxidation reactor;

preferably, the external energy field generating device comprises an ultraviolet light generating device and an ultrasonic generating device;

preferably, the ultraviolet light generating device is arranged at the top of the advanced oxidation reactor;

preferably, the ultrasound generating means comprises an ultrasound probe;

10. Use of the method according to any one of claims 1 to 7, characterized in that the method is used in the metallurgical industry;

preferably, the method is used for tungsten mineral raw material smelting.