KR20090090215A - Method for recovering molybdenum and copper product using solvent extraction from waste water - Google Patents

Abstract

A method for collecting copper and molybdenum remaining in effluent generated in a manufacturing process is provided to reduce mineral import by recycling the copper and the molybdenum with a counter-current extraction mode. A method for collecting copper and molybdenum remaining in effluent generated in a manufacturing process includes the following steps of: collecting a molybdenum ion in an organic solvent by adding an Amine series organic solvent(S10); separating the collected organic solvent from the effluent(S20); performing a counter-current extraction process of the molybdenum ion by adding an ammonia solution(S30); and collecting molybdenum by adding acid on the ammonia solution(S40).

Description

METHODS FOR RECOVERING MOLYBDENUM AND COPPER PRODUCT USING SOLVENT EXTRACTION FROM WASTE WATER}

The present invention relates to a method for recovering molybdenum and copper, and more particularly, to a method for recovering molybdenum and copper remaining in the wastewater generated in the molybdenum production process capable of recovering molybdenum and copper from the wastewater generated during the production of molybdenum. will be.

Molybdenum is mined in the form of molybdenum (MoS ₂ ), and to sell it, the molybdenum is converted into molybdenum trioxide (MoO ₃ ) type through a roasting process. At this time, the MoO ₃ is a leaching process using sulfuric acid (H ₂ SO ₄ ) to lower the content of Cu contained in MoO ₃ to less than 0.5% to meet the market delivery conditions only when the content of Cu is 0.5% or less. In this case, only Cu may be selectively leached, but expensive molybdenum is also leached in an aqueous solution in an ionic state.

As such, in the preparation of molybdenum trioxide (MoO ₃ ), an aqueous solution containing molybdenum is generated.

In the aqueous solution produced during the production of molybdenum trioxide (MoO ₃ ), a large amount of molybdenum eluted with copper (Cu) remains, and in fact, 1 ton of aqueous solution has an average of 21Kg of MoO ₄ ^2- form and copper is Cu It is known to contain about 12Kg in ²⁺ form.

Although it is recognized that molybdenum and copper are contained in the aqueous solution generated during the production of molybdenum, the price of molybdenum minerals has soared due to the inability to recover molybdenum and copper from the aqueous solution generated during the production of molybdenum. It is a situation that the aqueous solution is disposed of as waste water.

The present invention is to solve the above problems, remaining in the wastewater generated in the molybdenum manufacturing process to recycle resources and create added value by recovering high-purity molybdenum products and copper products from the wastewater generated in the current molybdenum manufacturing process The purpose is to provide a method for recovering molybdenum and copper.

To recover the molybdenum remaining in the wastewater generated in the molybdenum production process according to the present invention for achieving the above object, the step of collecting the molybdenum ion in the organic solvent by adding an organic solvent to the wastewater containing molybdenum Wow; Back-extracting the molybdenum ions from the organic solvent by adding ammonia water to the organic solvent in which the molybdenum ions are collected by the step; Molybdenum is recovered by the step of adjusting the pH by adding an acid to the ammonia water from which the molybdenum ion is back-extracted by the above step.

The method for recovering copper remaining in the wastewater generated in the molybdenum production process according to the present invention includes the steps of: collecting an molybdenum ion in the organic solvent by adding an organic solvent to the wastewater containing molybdenum; Capturing copper ions in the wastewater by adding an organic solvent to the wastewater from which the molybdenum ions are solvent-extracted by the step; Back extracting copper ions by adding sulfuric acid to the organic solvent; It characterized in that it comprises the step of recovering copper by electrolysis of copper ions back extracted in the sulfuric acid.

According to the method for recovering molybdenum and copper remaining in the wastewater generated in the molybdenum manufacturing process according to the present invention, by adding the molybdenum and copper discarded in the wastewater state, it is possible to create value added by recycling resources and import substitution effect Of course, the stabilization of supply and demand has the effect of enhancing the competitiveness of related industries.

As those skilled in the art would realize, the described embodiments may be modified in various ways, all without departing from the spirit or scope of the present invention. It is to be understood, however, that the present invention is not limited to the specific forms referred to in the description, but rather includes all modifications, equivalents, and substitutions within the spirit and scope of the invention as defined by the appended claims. Should be.

Hereinafter, a method for recovering molybdenum remaining in the wastewater generated in the molybdenum manufacturing process according to the present invention will be described in detail with reference to the accompanying drawings.

In the following description of the present invention, if it is determined that a detailed description of a related known function or configuration may unnecessarily obscure the subject matter of the present invention, the detailed description thereof will be omitted. Terms to be described later are terms defined in consideration of functions in the present invention, and may be changed according to intentions or customs of users or operators. Therefore, the definition should be made based on the contents throughout the specification.

1 is a process chart showing a process for recovering molybdenum remaining in the wastewater generated in the molybdenum production process according to the present invention, Figure 2 is a method for recovering molybdenum remaining in the wastewater generated in the molybdenum production process according to the present invention It is process drawing which showed the process of collect | recovering a copper product.

The recovery method of molybdenum remaining in the wastewater generated in the molybdenum production process according to the present invention is as follows.

(S10) Iron ion stabilization.

Waste water generated during the manufacturing process of molybdenum contains iron ions. Iron ions may precipitate in the form of goethite (FeOOH) due to the pH increase during the extraction of molybdenum, which is a post-process, and may cause paralysis of the solvent extraction process, and may lower the purity of molybdenum. It is

When sulfuric acid (H ₂ SO ₄ ) is added to the wastewater containing molybdenum, iron can be selectively separated from molybdenum ions by being in an ionic state.

FIG. 3A is a distribution graph of Fe (III) 0.179 mM vs pH at 5 M Cl ⁻ and 25 ° C., FIG. 3B is a distribution graph of Fe (III) 0.0179 M vs pH at 5 M Cl ⁻ and 25 ° C., FIG. 3C Is a distribution graph of Fe (III) 0.5 M vs pH at 1.5 M Cl ^- and 25 ° C., and the overall behavior of the iron chloride was examined by thermodynamic modeling, and as shown in FIGS. It is stable in ionic state, but it can be seen that precipitates in goethite (FeOOH) form when pH is increased.

At this time, the amount of sulfuric acid (H ₂ SO ₄ ) is added in consideration of the efficiency of the molybdenum extraction step and precipitation of iron ions in the post-process it is necessary to add 2.3 to 2.7%, preferably 2.5% by volume ratio. That is, if the amount of wastewater is 1L, 25 mL of sulfuric acid is added.

When sulfuric acid is added to the waste water, the pH is lowered to about 0.94 and the pH is raised to about 2 through the reaction of the organic solvent, which is an extraction step of molybdenum. When the pH is raised, the efficiency of the organic solvent (LIX-984N) is improved in the copper extraction process described later. This is because the organic solvent (LIX-984N manufactured by Cognis, Germany) shows maximum efficiency above pH 2.

(S20) Molybdenum Extraction.

The organic solvent is added to collect the molybdenum ions in the wastewater (wastewater containing molybdenum ions (MoO ₄ ^2- )) obtained through the stabilization of the iron ions.

The organic solvent is an Amine family capable of collecting molybdenum ions, and for example, the brand name Alamine 304-1 (manufactured by Cognis, Germany) may be used.

At this time, the reaction scheme is the same as in [Scheme 1].

In addition, since the organic solvent (Almine 304-1) has a high viscosity, it is necessary to lower the viscosity, and because the price is expensive, it can be diluted with a diluent. As a diluent, A-150 (manufacturer: Samsung Total Co., Ltd., Korea) may be used.

Almine 304-1 and A-150 can be diluted by mixing 1: 9 in volume ratio. Hereinafter, a mixture of an organic solvent (Almine 304-1) and a diluent (A-150) is referred to as a solvent extractant.

For example, in order to treat 1L of sulfuric acid-containing wastewater, 1800 mL of A-150 and 200 mL of Alamine 304-1 are mixed and diluted for 10 minutes first, and a solvent extractant (Almine 304-1 and A-150 is mixed). 2L of the solvent extractant is reacted with 1L of wastewater for 10 minutes to collect molybdenum ions.

At this time, each reaction time means a sufficient time. If the experiment is about 5 minutes, all reactions are completed, but it is preferable to react for 10 minutes to give sufficient time.

The reaction time may be appropriately adjusted in consideration of sufficient reaction and process time.

Scheme 1

^{_{N 3 R + (H +)}} (HSO 4 -) → N 3 R (H +) (HSO 4 -)

^{_{2 [N 3 R (H +}} ) (HSO 4 -)] + MoO 4 2- → 2 [N 3 R (H +)] (MoO 4 2-) + 2 (HSO 4 -)

(S30) Molybdenum Stripping.

Molybdenum ions are extracted in the solvent extractor (Almine 304-1 and A-150 mixed state) through the step (S20), and the solvent extractant from which the molybdenum ions are extracted is separated from the wastewater by specific gravity. Molybdenum ions are back extracted from the solvent extractor (molybdenum ion capture) separated from the wastewater. At this time, ammonia water (NH ₄ OH) is used for back extraction.

Ammonia water can be adjusted to a concentration of 12.5% by mixing and diluting a product having a concentration of 25% on the market with water and 1: 1.

The mixing ratio of aqueous ammonia and solvent extractant is 1: 4 by volume. When the mixing ratio of ammonia water and the solvent extractant is 5: 1 to 10: 1, and the mixing amount of the ammonia water is small, the reverse extraction efficiency of molybdenum ions decreases, and the mixing ratio of the ammonia water to the solvent extraction agent is 1: 1 to 3: 1. If too much molybdenum ions are back-extracted in the ammonia water, gel-type particles are generated during the pilot test, so that they do not easily release.

For example, 250 mL of ammonia water is added to 1 L of solvent extractant and reacted for 10 minutes. The reaction formula is shown in [Scheme 2].

Solvent extractant (Almine 304-1 and A-150 mixed state) in which the molybdenum ion is back-extracted with ammonia water can be reused in the step (S20).

Scheme 2

^{_{2 [N 3 R (H +}} )] (MoO 4 2-) + 2 (NH 4 + + OH -) → (2NH 4 + + MoO 4 2-) + H 2 O + [2N 3 R + OH -]

(S40) High Purity Molybdenum Recovery. Through the above process, a strong acid (10 M hydrochloric acid or 10 M nitric acid) is added to ammonia water containing molybdenum ions to lower the pH to 2 or less. It can be seen that molybdenum is present in the form of MoO ₃ in the region of pH 3 or lower, and accordingly, the molybdenum ion is adjusted to 2 or less to form MoO ₃ · H ₂ O. Precipitation in form. Reaction formula at this time is the same as [Scheme 3].

Scheme 3

^{2 (H + + Cl -)} + (2NH 4 + + MoO 4 2 -) → MoO 3 · H 2 O + 2 (NH 4 Cl)

The high purity molybdenum product precipitated through the above process may be recovered as a final high purity molybdenum product through a solid-liquid separation step.

Meanwhile, at the end of the precipitation reaction (S40), MoO ₃ · H ₂ O (precipitation reaction by hydrochloric acid) and MoO ₃ · 2H ₂ O (precipitation reaction by nitric acid) are produced. This product is a high-purity molybdenum product including crystal water, but when it is supplied to the market, the drying process (S41) is carried out to deliver the final high purity (MoO ₃ ) product by evaporating the crystal water attached to MoO ₃ · H ₂ O. It may be rough. The drying temperature is maintained at 350 to 450 ° C, preferably 400 ° C.

Figure 2 illustrates a process for high purity copper product recovery of the present invention starting with the waste water from the (S20) molybdenum extraction process and described in detail with reference to the accompanying drawings.

(S50) Copper Ion Loading (Loading). In the step (S20) using a solvent extractant (a mixture of Alamine 304-1 and A-150), the wastewater (copper containing) after collecting molybdenum ions is an organic solvent (Oxime series that can collect copper ions) And, for example, LIX-984N, manufactured by Cognis, Germany, to selectively collect only copper ions. At this time, the reaction scheme is the same as in [Scheme 4], and the organic solvent (LIX-984N) is used by mixing a diluent. A diluent may be used, for example, under the trade name Kerosen (manufactured by Hyundai Oilbank Co., Ltd.). The reaction time and dilution time with the waste water should be given at least 10 minutes for sufficient reaction.

Scheme 4

2 Oxime-H ⁺ + Cu ²⁺ (waste water) → Oxime-Cu-Oxime + 2H ⁺

(S60) Copper ion stripping. In step (S50), the copper ions collected in the solvent extractor (that is, the organic solvent (LIX-984N) and the diluent (Kerosen) are mixed) are reversely extracted. In this case, sulfuric acid (H ₂ SO ₄ ) is used as the back extraction solution, and the solvent extraction agent which back-extracts copper ions is reused in the step (S50).

Sulfuric acid is mixed with 1/4 of the solvent extractant, for example, 250 mL is added when the solvent extractant is 1L. Here, sulfuric acid may be diluted to 20% by mixing a commercially available product of 10M concentration and water, for example, is prepared in 250mL by mixing 50mL of 10M sulfuric acid and 200mL of water. Reaction formula at this time is the same as [Scheme 5].

Scheme 5

Oxime-Cu-Oxime + 2H ⁺ → 2Oxime-H ⁺ + Cu ²⁺

(S70) High Purity Copper Product Recovery. In step (S60), the copper present in the sulfuric acid (H ₂ SO ₄ ) in an ionic state is recovered to a high purity copper product using electrolysis. Reaction formula at this time is the same as [Scheme 6]. In addition, sulfuric acid (H ₂ SO ₄ ) in which the copper ions have been recovered may be reused as a back extract in the step (S60).

Scheme 6

Cathode: Cu ²⁺ + 2e → Cu

Anode: H ₂ O → 2H ⁺ + 1 / 2O ₂ + 2e

Overall reaction: Cu ^{2 +} + H ₂ O → Cu (99.99%) + 2H ⁺ + 1 / 2O ₂ ↑

1 is a process chart showing a process of a high purity molybdenum product recovery method using a solvent extraction method from the wastewater generated in the molybdenum production process according to the present invention.

Figure 2 is a process chart showing a process of high purity copper product recovery method using a solvent extraction method from the wastewater generated in the molybdenum production process according to the present invention.

3A to 3C are graphs showing that iron ions change to goethite, respectively.

Claims (5)

Capturing molybdenum ions in the organic solvent by adding an Amine-based organic solvent to molybdenum-containing wastewater; Separating the organic solvent in which the molybdenum ions are collected by the step from the wastewater, and then adding the ammonia water to the organic solvent to back extract the molybdenum ions from the organic solvent; Recovering molybdenum and copper remaining in the wastewater generated in the molybdenum manufacturing process, comprising the step of recovering molybdenum by adding an acid to the ammonia water from which the molybdenum ion is back extracted by the step to pH 2 or less Way. Capturing molybdenum ions in the organic solvent by adding an organic solvent of Oxime series to the wastewater containing molybdenum; Capturing copper ions in the wastewater by adding an organic solvent to the wastewater from which the molybdenum ions are solvent-extracted by the step; Back extracting copper ions by adding sulfuric acid to the organic solvent; Recovering copper from the wastewater generated in the molybdenum manufacturing process, comprising: recovering copper by electrolyzing copper ions extracted back to the sulfuric acid. The method of claim 1 or 2, wherein prior to the molybdenum ion capture step, The addition of sulfuric acid (H ₂ SO ₄ ) to the wastewater containing molybdenum and stabilizing the iron ions in the wastewater in the molybdenum ion collection step further comprises the wastewater generated in the molybdenum manufacturing process, characterized in that Method for recovering molybdenum and copper remaining in the. The method of claim 1, wherein in the collecting of molybdenum ions, the solvent extractant diluting the organic solvent with a diluent is mixed in a volume ratio of 2: 2 with respect to the wastewater. Recovery method of molybdenum and copper. The molybdenum and copper remaining in the wastewater generated in the molybdenum manufacturing process of claim 4, wherein in the molybdenum back extraction step, the solvent extractant and the ammonia water are mixed at a volume ratio of 4: 1 to extract molybdenum ions. Recovery method of the.

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