阅读说明：本技术 一种从废催化剂碱性溶液中回收钼的方法 (Method for recovering molybdenum from waste catalyst alkaline solution ) 是由 蒲年文 刘磊 付云枫 张忠裕 贾强方 于 2021-06-02 设计创作，主要内容包括：本发明公开了一种从废催化剂碱性溶液中回收钼的方法,包括以下步骤：S1、配制胺类萃取剂；S2、调节钼溶液的pH,用配制萃取剂萃取钼；S3、使用反萃剂反萃钼,得到高浓度含钼溶液；S4、往含钼溶液中加入酸沉试剂,固液分离得到钼沉淀产物,本发明方法可用于碱性溶液中钼的回收,不需要将溶液调为酸性,缩短了工艺流程,而且钼的萃取率高；本发明中使用的萃取剂和酸沉试剂便宜易得,萃取过程以及后续的钼沉淀过程操作简单,便于后续工业化应用。(The invention discloses a method for recovering molybdenum from a waste catalyst alkaline solution, which comprises the following steps: s1, preparing an amine extractant; s2, adjusting the pH value of the molybdenum solution, and extracting molybdenum by using a prepared extracting agent; s3, back extracting molybdenum by using a back extractant to obtain a high-concentration molybdenum-containing solution; s4, adding an acid precipitation reagent into the molybdenum-containing solution, and carrying out solid-liquid separation to obtain a molybdenum precipitation product, wherein the method can be used for recovering molybdenum in an alkaline solution, does not need to adjust the solution to be acidic, shortens the process flow, and has high extraction rate of molybdenum; the extracting agent and the acid precipitation agent used in the invention are cheap and easily available, and the extraction process and the subsequent molybdenum precipitation process are simple to operate and convenient for subsequent industrial application.)

1. A method for recovering molybdenum from waste catalyst alkaline solution is characterized by comprising the following steps:

s1, preparing an amine extractant;

s2, adjusting the pH value of the molybdenum solution, and extracting molybdenum by using a prepared extracting agent;

s3, back extracting molybdenum by using a back extractant to obtain a high-concentration molybdenum-containing solution;

s4, adding an acid precipitation reagent into the molybdenum-containing solution, and carrying out solid-liquid separation to obtain a molybdenum precipitation product.

2. The method for recovering molybdenum from waste catalyst alkaline solution according to claim 1, wherein the composition of the synergistic extraction agent used in S1 is N235 (trialkylamine), Cynex272 (di (2, 2, 4-trimethylpentyl) phosphonic acid) and sulfonated kerosene.

3. The method for recovering molybdenum from alkaline solution of spent catalyst as claimed in claim 2, wherein the volume percentages of N235, Cynex272 and sulfonated kerosene in the extractant are 5% -45%, 1% -20% and 0% -90%, respectively.

4. The method for recovering molybdenum from the alkaline solution of the waste catalyst in claim 2, wherein the pretreatment method of the synergic extractant before extraction is as follows: mixing and contacting an N235 extractant with an acid solution, stirring for a period of time, separating out a water phase, and preparing the extractant by using an organic phase.

5. The method for recovering molybdenum from the alkaline solution of the spent catalyst according to claim 4, wherein the acid solution is one or more of hydrochloric acid, nitric acid and sulfuric acid, and the concentration of the acid solution is 0.5mol/L to 3 mol/L.

6. The method for recovering molybdenum from the alkaline solution of the waste catalyst in claim 1, wherein the pH value of the molybdenum solution in S2 is 5-9, and the molybdenum content is less than or equal to 50 g/L.

7. The method of claim 1, wherein the alkaline solution of the molybdenum-containing solution in S3 is extracted and separated by an extractant, and the raffinate, i.e. the low-concentration molybdenum-containing solution, is subjected to stripping to obtain the high-concentration molybdenum-containing solution.

8. The method for recovering molybdenum from alkaline solution of spent catalyst according to claim 7, wherein the stripping process uses at least one of ammonia solution and sodium hydroxide solution as stripping agent.

9. The method for recovering molybdenum from the alkaline solution of the waste catalyst according to claim 1, wherein the acid precipitation reagent is hydrochloric acid added into the S4, the temperature is controlled to be 40-45 ℃, the final pH is 1-3, and the molybdenum precipitation product is obtained by solid-liquid separation.

Technical Field

The invention relates to the technical field of molybdenum recovery, in particular to a method for recovering molybdenum from a spent catalyst alkaline leaching solution.

Background

The waste catalyst usually adopts oxides of heavy metals such as titanium, molybdenum, vanadium, tungsten and the like as carriers and active ingredients, if the waste catalyst is randomly piled or simply buried, a large amount of substances contained in the waste catalyst can slowly enter the environment, so that serious environmental pollution, particularly pollution to underground water, is closely related to the health of human beings. Therefore, the recovery of metals and other useful components from the waste catalyst is particularly important, which not only can reduce the pollution of the waste catalyst to the environment caused by direct discharge, but also has certain economic benefit and enhances the competitive power of enterprises, and the molybdenum element in the waste catalyst is more important. Molybdenum is a rare metal with high melting point, and the chemical products of molybdenum have wide application in the fields of petroleum industry, metal corrosion prevention, pigment chemical industry and the like. In the field of metal processing, molybdenum is widely applied to manufacturing high-temperature dies, and the molybdenum is doped in stainless steel, so that the corrosion resistance can be greatly improved, the high-temperature strength can be increased, and the weldability can be improved. In the electronics industry, such as flat panel display devices, emission tips made of molybdenum have the advantages of short response time, wide temperature range tolerance, low power consumption, clarity, brightness, and durability. Therefore, the recovery of molybdenum in solution has important economic value, and the purity of molybdenum is also important for the development and application of high technology.

Currently, as for the recovery treatment of the spent catalyst alkaline leaching molybdenum-containing solution, the most common method is to separate and recover molybdenum by separating molybdenum from the solution through precipitation, activated carbon adsorption, solvent extraction, ion exchange, and the like. Chinese patent CN 107512734B discloses a method for separating tungsten, molybdenum and vanadium from a spent catalyst leaching solution, in which calcium chloride is added to precipitate tungsten and molybdenum to generate calcium tungstate and calcium molybdate, so that tungsten and molybdenum are well separated from the vanadium solution, but the subsequent tungsten and molybdenum also need to be leached by phosphoric acid to separate tungsten and molybdenum. Chinese patent CN 110656242 a discloses a method for recovering molybdenum metal in wastewater, which uses organic tertiary amine extractant Alamine304 to extract molybdenum at 60 ℃ compared with O/a 1:5, the method is simple and easy, and has high extraction rate, but the method is only suitable for acidic systems, and consumes a large amount of acid for alkaline solutions, which results in waste. Chinese patent CN 107385211A discloses that imidazole compounds extract and separate vanadium and molybdenum in an alkaline solution system containing vanadium and molybdenum, the extraction separation coefficient is about 5:1 at most, but vanadium and molybdenum in the solution are almost extracted at the same time, and the separation of the vanadium and the molybdenum cannot be realized.

Disclosure of Invention

The present invention is directed to a method for recovering molybdenum from a spent catalyst alkaline solution to solve the problems set forth in the background art.

In order to achieve the purpose, the invention provides the following technical scheme that the method comprises the following steps: a method for recovering molybdenum from a spent catalyst alkaline solution comprises the following steps:

s1, preparing an amine extractant;

s2, adjusting the pH value of the molybdenum solution, and extracting molybdenum by using a prepared extracting agent;

s3, back extracting molybdenum by using a back extractant to obtain a high-concentration molybdenum-containing solution;

s4, adding an acid precipitation reagent into the molybdenum-containing solution, and carrying out solid-liquid separation to obtain a molybdenum precipitation product.

Preferably, the synergistic extractant used in S1 consists of N235 (trialkylamine), Cynex272 (bis (2, 2, 4 trimethylpentyl) phosphonic acid) and sulfonated kerosene.

Preferably, the volume percentages of the N235, the Cynex272 and the sulfonated kerosene in the extracting agent are respectively 5-45%, 1-20% and 0-90%.

Preferably, the pretreatment method of the synergistic extraction agent before extraction is as follows: mixing and contacting an N235 extractant with an acid solution, stirring for a period of time, separating out a water phase, and preparing the extractant by using an organic phase.

Preferably, the acid solution is one or more of hydrochloric acid, nitric acid and sulfuric acid, and the concentration of the acid solution is 0.5-3 mol/L.

Preferably, the pH value of the molybdenum solution in the S2 is 5-9, and the molybdenum content is less than or equal to 50 g/L.

Preferably, the alkaline solution of the molybdenum-containing solution in S3 is extracted and separated by using an extractant, and the loaded organic phase is back-extracted with a raffinate, i.e., a low-concentration molybdenum-containing solution, to obtain a high-concentration molybdenum-containing solution.

Preferably, at least one of an ammonia solution and a sodium hydroxide solution is used as a stripping agent in the stripping process.

Preferably, the acid precipitation reagent is added into S4, hydrochloric acid is used as the acid precipitation reagent, the temperature is controlled to be 40-45 ℃, the final pH value is 1-3, and the molybdenum precipitation product is obtained through solid-liquid separation.

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

1. the method can be used for recovering molybdenum in the alkaline solution, does not need to adjust the solution to be acidic, shortens the process flow and has high extraction rate of molybdenum.

2. The extracting agent and the acid precipitation agent used in the invention are cheap and easily available, and the extraction process and the subsequent molybdenum precipitation process are simple to operate and convenient for subsequent industrial application.

3. The method extracts and separates molybdenum from the alkaline solution and precipitates the molybdenum, thereby realizing the recycling of the molybdenum in the molybdenum-containing solution, and the molybdenum precipitation product has certain economic value.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The invention provides a technical scheme that: a method for recovering molybdenum from a spent catalyst alkaline solution comprises the following steps:

s1, preparing an amine extractant;

s2, adjusting the pH value of the molybdenum solution, and extracting molybdenum by using a prepared extracting agent;

s3, back extracting molybdenum by using a back extractant to obtain a high-concentration molybdenum-containing solution;

s4, adding an acid precipitation reagent into the molybdenum-containing solution, and carrying out solid-liquid separation to obtain a molybdenum precipitation product.

Preferably, the synergistic extractant used in S1 consists of N235 (trialkylamine), Cynex272 (bis (2, 2, 4 trimethylpentyl) phosphonic acid) and sulfonated kerosene.

Wherein, the volume percentages of N235, Cynex272 and sulfonated kerosene in the extracting agent are respectively 5-45%, 1-20% and 0-90%.

The pretreatment method of the synergistic extraction agent before extraction comprises the following steps: mixing and contacting an N235 extractant with an acid solution, stirring for a period of time, separating out a water phase, and preparing the extractant by using an organic phase.

Wherein the acid solution is one or more of hydrochloric acid, nitric acid and sulfuric acid, and the concentration of the acid solution is 0.5-3 mol/L.

Wherein the pH value of the molybdenum solution in the S2 is 5-9, and the molybdenum content is less than or equal to 50 g/L.

And extracting and separating the alkaline solution of the molybdenum-containing solution in the S3 by using an extracting agent, wherein the raffinate, namely the low-concentration molybdenum-containing solution, is subjected to back extraction on the loaded organic phase to obtain the high-concentration molybdenum-containing solution.

Wherein at least one of an ammonia water solution and a sodium hydroxide solution is adopted as a stripping agent in the stripping process.

Wherein, the acid precipitation reagent is hydrochloric acid added into the S4, the temperature is controlled to be 40-45 ℃, the final pH is 1-3, and the molybdenum precipitation product is obtained by solid-liquid separation.

Example 1

(1) 250mL of hydrochloric acid solution (1mol/L) and 250mL of N235 were placed in a 500mL beaker and stirred at room temperature. After 60min, phase separation is carried out by using a separating funnel, the upper layer yellow N235 is taken for use, N235+ Cynex272+ sulfonated kerosene extracting agent is prepared according to the proportion, and the materials are stirred for one hour at room temperature and uniformly mixed;

(2) the solution containing molybdenum with pH value of 8 is adjusted, and the solution containing molybdenum with pH value of 3.3g/L, phosphorus with pH value of 0.05g/L, magnesium with pH value of 0.21g/L and sodium with pH value of 18.2g/L is extracted by using an extracting agent. Compared with the ratio of O/A to 1:1, the stirring speed is 500rpm, the stirring is carried out for 10min at the room temperature of 25 ℃, the standing is carried out for 5min, the organic phase and the water phase are separated for analysis, and the molybdenum, the phosphorus, the magnesium and the sodium in the raffinate are 0.0025g/L, 0.049g/L, 0.196g/L and 18.1g/L respectively;

(3) taking the extracted organic phase and 15% ammonia water according to the ratio of O/A to 1:2, stirring at 500rpm at room temperature of 25 ℃ for 7min, standing for 5min, then transferring to a separating funnel, standing for 5min, separating the organic phase and the aqueous phase, and obtaining a stripping solution with the molybdenum concentration of 6.46 g/L;

(4) and (3) regulating the final pH value of the stripping solution obtained in the previous step to 1.0 by using hydrochloric acid at 45 ℃, precipitating tungsten and molybdenum, and performing solid-liquid separation to obtain a molybdenum precipitation product. The precipitation rate of molybdenum was measured to be 83%.

Example 2

(1) 250mL of hydrochloric acid solution (1mol/L) and 250mL of N235 were placed in a 500mL beaker and stirred at room temperature. After 60min, phase separation is carried out by using a separating funnel, the upper layer yellow N235 is taken for use, N235+ Cynex272+ sulfonated kerosene extracting agent is prepared according to the proportion, and the materials are stirred for one hour at room temperature and uniformly mixed;

(2) the pH value of the molybdenum-containing solution is adjusted to 7, and the solution containing 3.3g/L of molybdenum, 0.052g/L of phosphorus, 0.21g/L of magnesium and 18.2g/L of sodium is extracted by using an extracting agent. Compared with the ratio of O/A to 1:1, the stirring speed is 500rpm, the stirring is carried out for 10min at the room temperature of 25 ℃, the standing is carried out for 5min, the organic phase and the water phase are separated for analysis, and the raffinate contains 0.0011g/L of molybdenum, 0.050g/L of phosphorus, 0.195g/L of magnesium and 18.1g/L of sodium;

(3) taking the extracted organic phase and 15% ammonia water according to the ratio of O/A to 1:2, stirring at 500rpm at room temperature of 25 ℃ for 7min, standing for 5min, then transferring to a separating funnel, standing for 5min, separating the organic phase and the aqueous phase, and obtaining a stripping solution with the molybdenum concentration of 6.45 g/L;

(4) after extraction is finished, hydrochloric acid is used for adjusting the final pH value of the stripping solution to 1.0 at 45 ℃, tungsten and molybdenum are precipitated, and solid-liquid separation is carried out to obtain a molybdenum-tungsten precipitation product. The precipitation rate of molybdenum was measured to be 83%.

Example 3

(1) 250mL of hydrochloric acid solution (1mol/L) and 250mL of N235 were placed in a 500mL beaker and stirred at room temperature. After 60min, phase separation is carried out by using a separating funnel, the upper layer yellow N235 is taken for use, N235+ Cynex272+ sulfonated kerosene extracting agent is prepared according to the proportion, and the mixture is stirred for one hour at room temperature and is uniformly mixed;

(2) the pH value of the molybdenum solution is adjusted to 8, and the solution containing 2.35g/L of molybdenum, 0.013g/L of phosphorus, 1.41g/L of magnesium and 18.2g/L of sodium is extracted by using an extracting agent. Using the phase ratio of O/A to 1:1, stirring at 500rpm at room temperature of 25 ℃ for 10min, standing for 5min, separating an organic phase from an aqueous phase, wherein the raffinate contains 0.0031g/L of molybdenum, 0.012g/L of phosphorus, 1.39g/L of magnesium and 18.1g/L of sodium;

(3) taking the extracted organic phase and 15% ammonia water according to the ratio of O/A to 1:2, stirring at 500rpm, stirring at room temperature of 25 ℃ for 7min, standing for 5min, then transferring to a separating funnel, standing for 5min, separating the organic phase and the aqueous phase, and analyzing to obtain a stripping solution with the molybdenum concentration of 4.65 g/L;

(4) after the extraction was completed, molybdenum was precipitated by adjusting the final pH of the stripping solution to 1.0 using hydrochloric acid at 30 ℃. And carrying out solid-liquid separation to obtain a molybdenum precipitate product. The precipitation rate of molybdenum was measured to be 81%.

Example 4:

(1) 250mL of hydrochloric acid solution (1mol/L) and 250mL of N235 were placed in a 500mL beaker and stirred at room temperature. After 60min, phase separation is carried out by using a separating funnel, the upper layer yellow N235 is taken for use, N235+ Cynex272+ sulfonated kerosene extracting agent is prepared according to the proportion, and the mixture is stirred for one hour at room temperature and is uniformly mixed;

(2) the pH value of the molybdenum solution is adjusted to 8, and the solution containing 2.35g/L of molybdenum, 0.013g/L of phosphorus, 1.41g/L of magnesium and 18.2g/L of sodium is extracted by using an extracting agent. Using the phase ratio of O/A to 1:1, stirring at 500rpm at room temperature of 25 ℃ for 10min, standing for 5min, separating an organic phase from an aqueous phase, wherein the raffinate contains 0.0031g/L of molybdenum, 0.012g/L of phosphorus, 1.39g/L of magnesium and 18.1g/L of sodium;

(3) taking the extracted organic phase and 20% ammonia water according to the ratio of O/A to 1:2, stirring at 500rpm, stirring at room temperature of 25 ℃ for 7min, standing for 5min, then transferring to a separating funnel, standing for 5min, separating the organic phase and the aqueous phase, and analyzing to obtain a stripping solution with the molybdenum concentration of 4.59 g/L;

(4) after the extraction was completed, molybdenum was precipitated by adjusting the final pH of the stripping solution to 1.0 using hydrochloric acid at 45 ℃. And carrying out solid-liquid separation to obtain a molybdenum precipitate product. The precipitation rate of molybdenum was measured to be 83%.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims and their equivalents.