阅读说明：本技术 一种回收废水中稀有金属的方法 (Method for recycling rare metals in wastewater ) 是由 李德坤 于 2018-06-29 设计创作，主要内容包括：本发明涉及废水处理领域,公开了一种回收废水中稀有金属的方法,将含钼酸性废水是将钼焙砂在90℃温度下、固液比为1∶3、反应1h后过滤,随后对滤液进行1-2小时的搅拌,再采用由Alamine304-1或N235复配磷酸三丁酯和煤油而成的萃取剂,进行多级萃取回收钼,油相采用碱液反萃；有机叔胺类萃取剂Alamine304-1或N235同磷酸三丁酯和煤油混合的萃取剂,其组成的体积比为Alamine304-1+TBP+煤油或N235+TBP+煤油：VALAMINE∶VTBP∶V煤油＝1∶2∶7和VN235∶VTBP∶V煤油＝1∶3∶6。(The invention relates to the field of wastewater treatment, and discloses a method for recovering rare metals in wastewater, which is characterized in that molybdenum-containing acidic wastewater is obtained by reacting molybdenum calcine at the temperature of 90 ℃ for 1 to 3 in a solid-liquid ratio and then filtering the reaction product after 1 hour, then stirring the filtrate for 1 to 2 hours, then performing multistage extraction by using an extractant prepared by compounding tributyl phosphate and kerosene with Alamine304-1 or N235 to recover molybdenum, and performing back extraction on an oil phase by using alkali liquor; the volume ratio of the organic tertiary amine extractant Alamine304-1 or N235 to the extractant mixed with tributyl phosphate and kerosene is Alamine304-1+ TBP + kerosene or N235+ TBP + kerosene: VALAMINE: VTBP: V kerosene 1: 2: 7 and VN 235: VTBP: V kerosene 1: 3: 6.)

1. A method for recovering rare metals in wastewater is characterized by comprising the following steps:

the molybdenum-containing acidic wastewater is prepared by reacting molybdenum calcine at 90 ℃ for 1: 3 in a solid-to-liquid ratio for 1h, filtering, stirring the filtrate for 1-2 h, performing multistage extraction by using an extractant prepared by compounding Alamine304-1 or N235 with tributyl phosphate and kerosene, and recovering molybdenum, wherein the oil phase is subjected to back extraction by using alkali liquor; the volume ratio of the organic tertiary amine extractant Alamine304-1 or N235 to the extractant mixed with tributyl phosphate and kerosene is Alamine304-1+ TBP + kerosene or N235+ TBP + kerosene: VALAMINE: VTBP: V kerosene 1: 2: 7 and VN 235: VTBP: V kerosene 1: 3: 6.

2. The method according to claim 1, wherein the extractant is acidified with 4.5mol/l nitric acid after the preparation.

3. The method for recovering rare metals in wastewater according to claim 1, wherein the volume ratio of acidification of the extracting agent V oil phase to V acid is 1: 0.5-1, shaking is carried out for 5min, standing is carried out for 30min, and the extracting agent used in the process is obtained through separation.

4. The method for recovering rare metals in wastewater according to claim 1, wherein the extraction process adopts three-stage or five-stage cross-flow extraction of molybdenum; mixing and oscillating the same oil and water phases of each stage for 2min, standing for 10min, separating, and oscillating the raffinate of each stage for 5-10 min by ultrasonic waves for next-stage extraction treatment.

5. The method for recovering rare metals in wastewater according to claim 1, characterized in that Alamine304-1+ TBP + kerosene extraction agent is adopted, the extraction process comprises the steps of extracting according to the volume ratio of oil phase to water phase of 1: 5 at the temperature of 60 ℃, vibrating the two phases in a contact manner for 2min, standing for 10min, and separating; the raffinate is used for the next extraction treatment, and the oil phase is to be back-extracted.

6. The method for recovering rare metals in wastewater according to claim 1, wherein the raffinate obtained by separation is subjected to ultrasonic oscillation at 30 ℃ for 10min and then used for next-stage extraction.

7. The method for recovering rare metals in wastewater according to claim 1, characterized in that the N235+ TBP + kerosene extraction agent is extracted at room temperature according to the volume ratio V oil phase to V water phase being 1: 5, the two phases are contacted and shaken for 2min, and then kept still for 10min, and separated; the raffinate is used for the next extraction treatment, and the oil phase is to be back-extracted.

8. The method for recovering rare metals in wastewater according to claim 1, wherein the raffinate obtained by separation is subjected to ultrasonic oscillation at 30 ℃ for 10min and then used for next-stage extraction.

9. The method for recovering rare metals in wastewater according to claim 1, wherein in the process of recovering molybdenum by oil phase back extraction, 10% -15% alkali liquor is adopted to be mixed with oil phase, and the mixture is shaken for 5min, kept stand for 30min and separated.

10. The method for recovering rare metals in wastewater according to claim 1, characterized in that 4.5mol/l nitric acid is adopted for oil phase regeneration to be mixed with the oil phase, the mixture is shaken for 10min, kept stand for 30min and separated to obtain a regenerated oil phase.

Technical Field

The invention relates to the field of wastewater treatment, in particular to a method for recovering rare metals in wastewater.

Background

In the traditional production for preparing ammonium molybdate, molybdenum calcine is pickled, ammonia is soaked, acid is deposited, ammonia is dissolved, and ammonium dimolybdate is prepared by evaporation and crystallization. The process for producing ammonium dimolybdate in an environment-friendly way is imperative. For example, CN201010149800.1 discloses a method for extracting molybdenum from waste materials in the field of ammonium molybdate production, which adopts a process for producing ammonium dimolybdate by washing molybdenum calcine, and can solve the problem of ammonia nitrogen pollution, but in the implementation process of the process, it is found that the molybdenum content in wastewater generated by washing molybdenum calcine with water is high, and can reach about 10g/l on average, and the pH value is about 2.5. Compared with the waste water produced by the prior art for pickling the molybdenum calcine, the molybdenum content of the waste water is about 1g/l, and the pH value is about 1.0. Therefore, the molybdenum in the molybdenum calcine washed by water in the process is imperative to be recovered.

Disclosure of Invention

The invention aims to provide a method for effectively reducing pollution and recovering rare metals in wastewater with high yield aiming at the defects of the prior art.

The purpose of the invention is realized by the following technical scheme: a method for recycling an alloy, characterized by comprising the steps of:

a method for recovering rare metals in wastewater, molybdenum-containing acidic wastewater is prepared by reacting molybdenum calcine at 90 ℃ for 1: 3 in a solid-to-liquid ratio, filtering, stirring the filtrate for 1-2 hours, extracting with an extractant prepared by compounding Alamine304-1 or N235 with tributyl phosphate and kerosene in a multistage manner to recover molybdenum, and back-extracting the oil phase with an alkali liquor; the volume ratio of the organic tertiary amine extractant Alamine304-1 or N235 to the extractant mixed with tributyl phosphate and kerosene is Alamine304-1+ TBP + kerosene or N235+ TBP + kerosene: VALAMINE: VTBP: V kerosene 1: 2: 7 and VN 235: VTBP: V kerosene 1: 3: 6. Furthermore, the extractant is acidified by 4.5mol/l nitric acid after preparation.

Further, the acidifying volume ratio of the extracting agent V oil phase to V acid is 1: 0.5-1, the extracting agent used in the process is obtained by oscillating for 5min, standing for 30min and separating.

Further, three-stage or five-stage cross flow extraction of molybdenum is adopted in the extraction process; mixing and oscillating the same oil and water phases of each stage for 2min, standing for 10min, separating, and oscillating the raffinate of each stage for 5-10 min by ultrasonic waves for next-stage extraction treatment.

Further, adopting Alamine304-1+ TBP + kerosene extraction agent, extracting at 60 deg.C according to volume ratio of oil phase to water phase of 1: 5, oscillating for 2min, standing for 10min, and separating; the raffinate is used for the next extraction treatment, and the oil phase is to be back-extracted.

Further, the raffinate obtained by separation was subjected to ultrasonic oscillation at 30 ℃ for 10min and then used for the next-stage extraction.

Further, extracting with N235+ TBP + kerosene extraction agent at room temperature at volume ratio of oil phase to water phase of 1: 5, oscillating for 2min, standing for 10min, and separating; the raffinate is used for the next extraction treatment, and the oil phase is to be back-extracted.

Further, the raffinate obtained by separation is subjected to ultrasonic oscillation at 30 ℃ for 10min and then is used for next-stage extraction.

Further, in the process of recovering molybdenum by back extraction of the oil phase, alkali liquor with the concentration of 10-15% is mixed with the oil phase, the mixture is oscillated for 5min, kept stand for 30min and separated.

Further, the oil phase regeneration adopts 4.5mol/l nitric acid to be mixed with the oil phase, the mixture is oscillated for 10min, kept stand for 30min and separated to obtain the regenerated oil phase.

The method for recovering rare metals in wastewater adopts the molybdenum extractant with industrial application value, and the molybdenum extractant is the amine extractant which has the characteristics of large capacity, good selectivity, suitability for various acid systems and high radiation stability. The tertiary amine in the amine extractant does not contain hydrogen in the molecular structure and does not form hydrogen bonds, so the tertiary amine has stronger extraction capability. The selection of the high-efficiency tertiary amine extractant becomes the important research point for extracting and recovering molybdenum in the waste liquid.

According to the method, an organic tertiary amine extractant Alamine304-1 is adopted, the molecular formula is (C12H25)3N or N235, the molecular formula is (C8H17)3N, the molybdenum metal in the molybdenum calcine waste liquid washed by water in the ammonium molybdate production process is extracted and recovered, the raffinate separated by each stage of extraction is treated by ultrasonic waves, the extraction rate is improved, and the extraction stages are reduced.

The method mainly comprises the following steps: the extractant is prepared by mixing Alamine304-1 or N235, tributyl phosphate and kerosene, the extractant is acidified, the wastewater is extracted in multiple stages, and meanwhile, ultrasonic oscillation treatment, alkali liquor back extraction, oil phase acidification regeneration and other processes are adopted for each stage of raffinate in the multiple-stage extraction, so that the recovery rate of metal molybdenum in the wastewater and the reuse of the extractant are achieved, the recovery rate of the metal molybdenum is above 95%, and the concentration of the metal molybdenum in the wastewater is reduced to below 0.5g/l from 10g/l, thereby achieving the requirement of wastewater discharge.

Detailed Description