Process for deeply recovering and enriching molybdenum in copper smelting smoke dust

Abstract

The invention discloses a deep recovery and enrichment process for molybdenum in copper smelting smoke dust, and belongs to the technical field of hydrometallurgy. The method comprises the following steps: uniformly mixing smoke dust and water according to a solid-to-liquid ratio S: L of 1: (2-4), adding 70-100g / L concentrated sulfuric acid, reacting at 70-85 DEG C for 0.5-1.5 hours, and filtering to obtain an acid leaching solution and acid leaching residues; mixing the pickle liquor with the molybdenum extraction organic phase according to a phase ratio O: A of 1: (7-9), performing extraction and phase splitting, mixing the molybdenum-loaded organic phase with a stripping agent according to a phase ratio O: A of (2-4): 1, and performing extraction and phase splitting to obtain stripping liquor 1; washing the acid leaching residues, uniformly mixing the washed acid leaching residues with water according to a solid-to-liquid ratio of S: L of 1: (2-4), adding 90-110g / L of sodium hydroxide, reacting at 70-85 DEG C for 0.5-1.5 hours, and filtering to obtain alkaline leaching liquid and alkaline leaching residues; mixing the alkaline leaching solution with the molybdenum extraction organic phase according to a phase ratio O: A of 1: (7-9), performing extraction and phase splitting, mixing the molybdenum-loaded organic phase with a stripping agent according to a phase ratio O: A of (2-4): 1, and performing extraction and phase splitting to obtain a stripping solution 2; and mixing the strip liquor 1 and the strip liquor 2, heating to reduce the volume of the solution, cooling to separate out crystals, and calcining the crystals at 550-650 DEG C for 1-2 hours. According to the method, the molybdenum content in the copper smelting smoke dust can be reduced to 0.02% or below, the purity of the prepared molybdenum trioxide is larger than 98%, and deep extraction and enrichment of molybdenum are achieved.

Description

Technical Field

[0001] This invention belongs to the field of hydrometallurgical technology, specifically relating to a process for deep recovery and enrichment of molybdenum in copper smelting flue dust. Background Technology

[0002] Copper smelting dust, as an important secondary resource, contains various valuable metallic elements, among which the recovery and enrichment of molybdenum resources is of significant strategic importance. Firstly, copper smelting dust contains 0.2-2% molybdenum, representing a considerable secondary resource; achieving the recycling of molybdenum resources is crucial for ensuring resource security. Secondly, the molybdenum in copper smelting dust mainly exists in the form of molybdenum oxide and molybdate, making it easier to separate than molybdenum in the ore, thus improving recovery rates and reducing costs and increasing efficiency for enterprises. Thirdly, copper smelting dust contains molybdenum and other heavy metals; improper treatment can cause long-term environmental pollution. Recovering molybdenum from the dust through hydrometallurgical processes while removing other harmful elements achieves harmless treatment of the dust, significantly reducing the environmental burden. However, after traditional acid leaching, the leaching residue typically still contains 0.3-0.5% molybdenum. Without further recovery, this molybdenum will disperse into subsequent lead, antimony, and other element recovery processes, resulting in metal loss. Therefore, there is an urgent need to develop a deep recovery and enrichment process for molybdenum in copper smelting flue dust, so as to further reduce the molybdenum content in leaching residue and achieve efficient recovery of molybdenum resources. Summary of the Invention

[0003] The purpose of this invention is to provide a process for the deep recovery and enrichment of molybdenum in copper smelting dust.

[0004] The objective of this invention is achieved by the deep recovery and enrichment process of molybdenum in copper smelting dust, comprising the following steps: Acid leaching: Copper smelting fumes and water are mixed evenly at a solid-liquid ratio of S:L=1:2~4, then 70~100g / L of concentrated sulfuric acid is added, the temperature is raised to 70~85℃, the mixture is stirred and reacted for 0.5~1.5h, and then filtered to obtain molybdenum-containing acid leaching solution and acid leaching residue. Acid leaching solution extraction and back-extraction: The molybdenum-containing acid leaching solution and the acidic molybdenum extraction organic phase were mixed at a ratio of O:A = 1:7~9, and then extracted by shaking at room temperature. After standing and phase separation, the molybdenum-loaded organic phase and the back-extraction agent were mixed at a ratio of O:A = 2~4:1, and then extracted by shaking at room temperature. After standing and phase separation, the molybdenum-containing back-extraction solution 1 was obtained. Alkaline leaching: After washing the acid leaching residue, mix it with water at a solid-liquid ratio of S:L=1:2~4, add 90~110g / L of sodium hydroxide, heat to 70~85℃, stir and react for 0.5~1.5h, and then filter to obtain molybdenum-containing alkaline leaching solution and alkaline leaching residue. Alkaline extraction and back-extraction: The molybdenum-containing alkaline extract and the alkaline molybdenum extraction organic phase were mixed at a ratio of O:A = 1:7~9, and then extracted by shaking at room temperature. After standing and phase separation, the molybdenum-loaded organic phase and the back-extraction agent were mixed at a ratio of O:A = 2~4:1, and then extracted by shaking at room temperature. After standing and phase separation, the molybdenum-containing back-extraction solution 2 was obtained. Evaporation crystallization: After mixing molybdenum-containing back-extraction solution 1 and molybdenum-containing back-extraction solution 2, the solution volume is reduced by heating and then cooled to allow ammonium molybdate crystals to crystallize out, thus obtaining ammonium molybdate crystals; Calcination and decomposition: heating ammonium molybdate crystals to 550~650℃ and maintaining the temperature for 1~2 hours will yield the target molybdenum trioxide.

[0005] The technical solution described in this invention has the following advantages compared with the prior art: (1) This process can achieve deep extraction of molybdenum. Acid leaching first removes more than 70% of the molybdenum from the flue dust, and then the acid leaching residue is leached with alkali. After leaching, the molybdenum content in the residue can be reduced to below 0.02%, the molybdenum leaching rate reaches 99.06%, and the purity of molybdenum trioxide is >98%.

[0006] (2) The acid leaching solution and the alkaline leaching solution are enriched by the extraction-back-extraction process. Both leaching solutions are back-extracted with ammonia water. The back-extracted solutions can be combined and then ammonium molybdate and molybdenum trioxide are prepared. The process is flexible, highly compatible, and can be widely adapted to complex dust components.

[0007] (3) Acid leaching, alkali leaching and extraction-back-extraction are all carried out at lower temperatures, which significantly reduces energy consumption and operating costs. The extracted organic phase can be reused, reducing the consumption of chemical reagents and improving the resource recycling rate. Attached Figure Description

[0008] Figure 1 This is a process flow diagram of the technical solution described in this invention. Detailed Implementation

[0009] The present invention will be further described below, but this is not intended to limit the invention in any way. Any modifications or substitutions made based on the teachings of the present invention shall fall within the scope of protection of the present invention.

[0010] The deep recovery and enrichment process of molybdenum in copper smelting dust described in this invention includes the following steps: Acid leaching: Copper smelting fumes and water are mixed evenly at a solid-liquid ratio of S:L=1:2~4, then 70~100g / L of concentrated sulfuric acid is added, the temperature is raised to 70~85℃, the mixture is stirred and reacted for 0.5~1.5h, and then filtered to obtain molybdenum-containing acid leaching solution and acid leaching residue. Acid leaching solution extraction and back-extraction: The molybdenum-containing acid leaching solution and the acidic molybdenum extraction organic phase were mixed at a ratio of O:A = 1:7~9, and then extracted by shaking at room temperature. After standing and phase separation, the molybdenum-loaded organic phase and raffinate were obtained. The molybdenum-loaded organic phase and the back-extraction agent were mixed at a ratio of O:A = 2~4:1, and then extracted by shaking at room temperature. After standing and phase separation, the molybdenum-containing back-extraction solution 1 was obtained. Alkaline leaching: After washing the acid leaching residue, mix it with water at a solid-liquid ratio of S:L=1:2~4, add 90~110g / L of sodium hydroxide, heat to 70~85℃, stir and react for 0.5~1.5h, and then filter to obtain molybdenum-containing alkaline leaching solution and alkaline leaching residue. Alkaline extraction and back-extraction: The molybdenum-containing alkaline leaching solution and the alkaline molybdenum extraction organic phase were mixed at a ratio of O:A = 1:7~9, and then extracted by shaking at room temperature. After standing and phase separation, the molybdenum-loaded organic phase and raffinate were obtained. The molybdenum-loaded organic phase and the back-extraction agent were mixed at a ratio of O:A = 2~4:1, and then extracted by shaking at room temperature. After standing and phase separation, the molybdenum-containing back-extraction solution 2 was obtained. Evaporation crystallization: After mixing molybdenum-containing back-extraction solution 1 and molybdenum-containing back-extraction solution 2, the solution volume is reduced by heating and then cooled to allow ammonium molybdate crystals to crystallize out, thus obtaining ammonium molybdate crystals; Calcination decomposition: heating ammonium molybdate crystals to 550~650℃ and maintaining the temperature for 1~2 hours will yield the target molybdenum trioxide.

[0011] The preferred solid-liquid ratio of copper smelting flue dust to water is S:L=1:3.

[0012] The preferred reaction time for acid leaching is 1 hour.

[0013] The preferred ratio of the molybdenum-containing acid leaching solution to the acidic molybdenum extraction organic phase is O:A=1:8.

[0014] The acidic molybdenum extraction organic phase is either tributyl phosphate or di(2-ethylhexyl)phosphoric acid.

[0015] In the acid leaching step, the raffinate can be returned to the acid leaching step.

[0016] The preferred solid-liquid ratio of the acid leaching residue to water is S:L = 1:3.

[0017] The concentration of sodium hydroxide is preferably 100 g / L.

[0018] The preferred reaction time for the alkaline leaching is 1 hour.

[0019] The preferred ratio of the molybdenum-containing alkaline leaching solution to the alkaline molybdenum extraction organic phase is O:A=1:8.

[0020] The alkaline molybdenum extraction organic phase is either trioctylamine or methyltrioctylammonium chloride.

[0021] In the alkaline extraction step, the raffinate can be returned to the alkaline leaching step.

[0022] The extraction temperature is preferably 20~30℃, and the extraction time is preferably 5 minutes. The settling time is preferably 5 minutes.

[0023] The preferred ratio of the molybdenum-supported organic phase to the stripping agent is O:A = 3:1.

[0024] The stripping agent is ammonia water with a concentration of 7~9 mol / L.

[0025] The preferred temperature for back-extraction is 20-30°C, and the preferred time is 5 minutes. The preferred settling time is 5 minutes.

[0026] In the evaporation and crystallization step, the heating temperature is 70-80°C. After heating reduces the solution volume by 60%, cooling causes ammonium molybdate crystals to precipitate.

[0027] Example 1

[0028] Acid leaching: Copper smelting fumes and water are mixed evenly at a solid-liquid ratio of S:L=1:3. Then, 85g / L of concentrated sulfuric acid is added, the temperature is raised to 75℃, and the mixture is stirred and reacted for 1 hour before filtration to obtain a molybdenum-containing acid leaching solution and acid leaching residue.

[0029] Acid leaching solution extraction and back-extraction: The molybdenum-containing acid leaching solution and the acidic molybdenum extraction organic phase (di(2-ethylhexyl)phosphoric acid) were mixed at a ratio of O:A=1:8, and extracted by shaking at room temperature for 5 min. After standing for 5 min and phase separation, the molybdenum-loaded organic phase was mixed with 8 mol / L ammonia water at a ratio of O:A=3:1, and extracted by shaking at room temperature for 5 min. After standing for 5 min and phase separation, the molybdenum-containing back-extraction solution 1 was obtained.

[0030] Alkali leaching: After washing the filtered acid leaching residue, mix it with water at a solid-liquid ratio of S:L=1:3, add 100g / L sodium hydroxide, heat to 80℃, stir and react for 1h, and then filter to obtain molybdenum-containing alkaline leaching solution and alkaline leaching residue.

[0031] Alkaline extraction and back-extraction: The molybdenum-containing alkaline extract and the alkaline molybdenum extraction organic phase (methyltrioctylammonium chloride) were mixed at a ratio of O:A=1:8, and extracted by shaking at room temperature for 5 min. After standing for 5 min, the phases were separated. The molybdenum-loaded organic phase and 8 mol / L ammonia water were mixed at a ratio of O:A=3:1, and extracted by shaking at room temperature for 5 min. After standing for 5 min, the phases were separated to obtain molybdenum-containing back-extraction solution 2.

[0032] Evaporation crystallization: After mixing molybdenum-containing back-extraction solution 1 and molybdenum-containing back-extraction solution 2, heat to 75°C to reduce the solution volume by 60%, then cool down to allow ammonium molybdate crystals to crystallize out, thus obtaining ammonium molybdate crystals.

[0033] Calcination decomposition: Ammonium molybdate crystals are heated to 600℃ and kept at a constant temperature for 1.5h to obtain the target molybdenum trioxide.

[0034] Example 2

[0035] Acid leaching: Copper smelting fumes and water are mixed evenly at a solid-liquid ratio of S:L=1:4. Then, 100g / L of concentrated sulfuric acid is added, the temperature is raised to 70℃, and the mixture is stirred and reacted for 1.5h before filtration to obtain a molybdenum-containing acid leaching solution and acid leaching residue.

[0036] Acid leaching solution extraction and back-extraction: The molybdenum-containing acid leaching solution and the acidic molybdenum extraction organic phase (di(2-ethylhexyl)phosphoric acid) were mixed at a ratio of O:A=1:9, and extracted by shaking at room temperature for 5 min. After standing for 5 min and phase separation, the molybdenum-loaded organic phase was mixed with 9 mol / L ammonia water at a ratio of O:A=4:1, and extracted by shaking at room temperature for 5 min. After standing for 5 min and phase separation, the molybdenum-containing back-extraction solution 1 was obtained.

[0037] Alkali leaching: After washing the filtered acid leaching residue, mix it with water at a solid-liquid ratio of S:L=1:4, add 110g / L sodium hydroxide, heat to 70℃, stir and react for 1.5h, and then filter to obtain molybdenum-containing alkaline leaching solution and alkaline leaching residue.

[0038] Alkaline extraction and back-extraction: The molybdenum-containing alkaline extract and the alkaline molybdenum extraction organic phase (methyltrioctylammonium chloride) were mixed at a ratio of O:A=1:9, and extracted by shaking at room temperature for 5 min. After standing for 5 min, the phases were separated. The molybdenum-loaded organic phase and 9 mol / L ammonia water were mixed at a ratio of O:A=4:1, and extracted by shaking at room temperature for 5 min. After standing for 5 min, the phases were separated to obtain molybdenum-containing back-extraction solution 2.

[0039] Evaporation crystallization: After mixing molybdenum-containing back-extraction solution 1 and molybdenum-containing back-extraction solution 2, heat to 80°C to reduce the solution volume by 60%, then cool down to allow ammonium molybdate crystals to crystallize out, thus obtaining ammonium molybdate crystals.

[0040] Calcination and decomposition: Ammonium molybdate crystals are heated to 650℃ and kept at a constant temperature for 1 hour to obtain the target molybdenum trioxide.

[0041] Example 3

[0042] Acid leaching: Copper smelting fumes and water are mixed evenly at a solid-liquid ratio of S:L=1:2. Then, 70g / L of concentrated sulfuric acid is added, the temperature is raised to 85℃, and the mixture is stirred and reacted for 0.5h before filtration to obtain a molybdenum-containing acid leaching solution and acid leaching residue.

[0043] Acid leaching solution extraction and back-extraction: The molybdenum-containing acid leaching solution and the acidic molybdenum extraction organic phase (di(2-ethylhexyl)phosphoric acid) were mixed at a ratio of O:A=1:7, and extracted by shaking at room temperature for 5 min. After standing for 5 min and phase separation, the molybdenum-loaded organic phase was mixed with 7 mol / L ammonia water at a ratio of O:A=2:1, and extracted by shaking at room temperature for 5 min. After standing for 5 min and phase separation, the molybdenum-containing back-extraction solution 1 was obtained.

[0044] Alkali leaching: After washing the filtered acid leaching residue, mix it with water at a solid-liquid ratio of S:L=1:2, add 90g / L sodium hydroxide, heat to 85℃, stir and react for 0.5h, and then filter to obtain molybdenum-containing alkaline leaching solution and alkaline leaching residue.

[0045] Alkaline extraction and back-extraction: The molybdenum-containing alkaline extract was mixed with the alkaline molybdenum extraction organic phase (methyltrioctylammonium chloride) at a ratio of O:A=1:7, and extracted by shaking at room temperature for 5 min. After standing for 5 min and phase separation, the molybdenum-loaded organic phase was mixed with 7 mol / L ammonia water at a ratio of O:A=2:1, and extracted by shaking at room temperature for 5 min. After standing for 5 min and phase separation, the molybdenum-containing back-extraction solution 2 was obtained.

[0046] Evaporation crystallization: After mixing molybdenum-containing back-extraction solution 1 and molybdenum-containing back-extraction solution 2, heat to 70°C to reduce the solution volume by 60%, then cool down to allow ammonium molybdate crystals to crystallize out, thus obtaining ammonium molybdate crystals.

[0047] Calcination and decomposition: Ammonium molybdate crystals are heated to 550℃ and kept at a constant temperature for 2 hours to obtain the target molybdenum trioxide.

Claims

1. A process for deep recovery and enrichment of molybdenum from copper smelting dust, characterized in that, Includes the following steps: Acid leaching: Copper smelting fumes and water are mixed evenly at a solid-liquid ratio of S:L=1:2~4, then 70~100g / L of concentrated sulfuric acid is added, the temperature is raised to 70~85℃, the mixture is stirred and reacted for 0.5~1.5h, and then filtered to obtain molybdenum-containing acid leaching solution and acid leaching residue. Acid leaching solution extraction and back-extraction: The molybdenum-containing acid leaching solution and the acidic molybdenum extraction organic phase were mixed at a ratio of O:A = 1:7~9, and then extracted by shaking at room temperature. After standing and phase separation, the molybdenum-loaded organic phase and the back-extraction agent were mixed at a ratio of O:A = 2~4:1, and then extracted by shaking at room temperature. After standing and phase separation, the molybdenum-containing back-extraction solution 1 was obtained. Alkaline leaching: After washing the acid leaching residue, mix it with water at a solid-liquid ratio of S:L=1:2~4, add 90~110g / L of sodium hydroxide, heat to 70~85℃, stir and react for 0.5~1.5h, and then filter to obtain molybdenum-containing alkaline leaching solution and alkaline leaching residue. Alkaline extraction and back-extraction: The molybdenum-containing alkaline extract and the alkaline molybdenum extraction organic phase were mixed at a ratio of O:A = 1:7~9, and then extracted by shaking at room temperature. After standing and phase separation, the molybdenum-loaded organic phase and the back-extraction agent were mixed at a ratio of O:A = 2~4:1, and then extracted by shaking at room temperature. After standing and phase separation, the molybdenum-containing back-extraction solution 2 was obtained. Evaporation crystallization: After mixing molybdenum-containing back-extraction solution 1 and molybdenum-containing back-extraction solution 2, the solution volume is reduced by heating and then cooled to allow ammonium molybdate crystals to crystallize out, thus obtaining ammonium molybdate crystals; Calcination and decomposition: heating ammonium molybdate crystals to 550~650℃ and maintaining the temperature for 1~2 hours will yield the target molybdenum trioxide.

2. The deep recovery and enrichment process of molybdenum in copper smelting dust according to claim 1, characterized in that, The solid-liquid ratio of the copper smelting flue dust to water is S:L=1:

3.

3. The deep recovery and enrichment process of molybdenum in copper smelting dust according to claim 1, characterized in that, The acid leaching reaction time is 1 hour.

4. The deep recovery and enrichment process of molybdenum in copper smelting dust according to claim 1, characterized in that, The ratio of the molybdenum-containing acid leaching solution to the acidic molybdenum extraction organic phase is O:A = 1:

8.

5. The deep recovery and enrichment process of molybdenum in copper smelting dust according to claim 1, characterized in that, The solid-liquid ratio of the acid leaching residue to water is S:L=1:

3.

6. The deep recovery and enrichment process of molybdenum in copper smelting dust according to claim 1, characterized in that, The alkaline leaching reaction time is 1 hour.

7. The deep recovery and enrichment process of molybdenum in copper smelting dust according to claim 1, characterized in that, The ratio of the molybdenum-containing alkaline leaching solution to the alkaline molybdenum extraction organic phase is O:A = 1:

8.

8. The deep recovery and enrichment process of molybdenum in copper smelting dust according to claim 1, characterized in that, The ratio of the molybdenum-loaded organic phase to the stripping agent is O:A = 3:

1.

9. The deep recovery and enrichment process of molybdenum in copper smelting dust according to any one of claims 1 or 8, characterized in that, The stripping agent is ammonia water with a concentration of 7~9 mol / L.

10. The deep recovery and enrichment process of molybdenum in copper smelting dust according to claim 1, characterized in that, In the evaporation and crystallization step, the heating temperature is 70~80℃.

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