CN-121976052-A - Method for transferring rhodium in rhodium-containing organic waste liquid to water phase through two-phase oxidation

Abstract

The invention relates to a method for transferring rhodium in rhodium-containing organic waste liquid to a water phase through two-phase oxidation, belonging to the technical field of precious metal regeneration metallurgy. According to the invention, a two-phase oxidation transfer system is adopted, a chlorine-containing aqueous phase is added into an in-situ active chlorine electrolysis unit for in-situ electrolysis to generate an active chlorine aqueous phase, carbon monoxide and the active chlorine aqueous phase are introduced into a two-phase contact unit for fully mixing and contacting with pretreated rhodium-containing organic waste liquid, and multi-stage oxidation-transfer reactions are sequentially carried out to obtain an oxidation-transfer reaction mixture, the oxidation-transfer reaction mixture is introduced into a phase separation unit and separated into a lower rhodium-containing aqueous phase and an upper organic phase by gravity, the upper organic phase returns to a 1 st stage mixing unit or an organic phase collecting unit through a three-way pipe I according to rhodium element content, and the lower rhodium-containing aqueous phase flows into the in-situ active chlorine electrolysis unit through a three-way pipe II or flows into an aqueous phase product collecting unit through a three-way pipe II as a rhodium-rich aqueous phase. The invention achieves a stable, treatable rhodium-rich aqueous phase while retaining the organic phase for reuse.

Inventors

• HAN JIBIAO
• WANG GUOZHEN
• YANG HAN
• WU YUEDONG
• Kang Xinke
• Ma Wangrui
• LIU KUO
• ZHANG CHUNXI
• YANG YIBIN
• WANG CHAO
• HE XINGWANG
• DONG HAIGANG
• YANG QUAN
• ZHAO JIACHUN
• LI YONG
• WU XILONG
• WANG HUAN

Assignees

• 云南贵金属实验室有限公司
• 贵研资源（易门）有限公司

Dates

Publication Date

20260505

Application Date

20260402

Claims (8)

1. 1. A method for transferring rhodium in rhodium-containing organic waste liquid to water phase through two-phase oxidation transfer is characterized in that a two-phase oxidation transfer system is adopted, the two-phase oxidation transfer system comprises a two-phase contact unit and an in-situ active chlorine electrolysis unit, the two-phase contact unit comprises a mixing unit, a phase separation unit, an organic phase collection unit and a water phase product collection unit, the serial mixing stage number of the mixing unit is 1-4, the inlet end of the mixing unit is a1 st mixing unit, the outlet of the mixing unit is communicated with the inlet of the phase separation unit, the organic phase outlet of the phase separation unit is respectively communicated with the inlet end of the 1 st mixing unit and the organic phase collection unit through a three-way pipe I, the inlet end of the 1 st mixing unit is communicated with the outlet of the in-situ active chlorine electrolysis unit, and the water phase outlet of the phase separation unit is respectively communicated with the water phase product collection unit and the inlet of the in-situ active chlorine electrolysis unit through a three-way pipe II; the method comprises the following specific steps: (1) Removing solid impurities from rhodium-containing organic waste liquid through solid-liquid separation, centrifuging, standing to remove water phase, and diluting with a diluent to obtain pretreated rhodium-containing organic waste liquid; (2) Preparing a chlorine-containing aqueous phase which contains hydrochloric acid and soluble chloride; (3) The pretreated rhodium-containing organic waste liquid is placed in a1 st-stage mixing unit of a two-phase contact unit, a chlorine-containing aqueous phase is added into an in-situ active chlorine electrolysis unit for in-situ electrolysis to generate an active chlorine aqueous phase, carbon monoxide and the active chlorine aqueous phase are introduced into the mixing unit of the two-phase contact unit and are fully mixed and contacted with the pretreated rhodium-containing organic waste liquid for orderly performing multistage oxidation-transfer reaction so as to enable rhodium to be oxidized and transferred to the aqueous phase to obtain an oxidation-transfer reaction mixture, and the oxidation-transfer reaction mixture is introduced into a phase separation unit and separated into a lower rhodium-containing aqueous phase and an upper organic phase by gravity; (4) When the rhodium content in the upper organic phase is greater than 0.005g/L, the upper organic phase returns to the 1 st stage mixing unit through a three-way pipe I, the lower rhodium-containing water phase flows into the in-situ active chlorine electrolysis unit through a three-way pipe II to carry out in-situ electrolysis to generate an active chlorine water phase, and then flows into the 1 st stage mixing unit to realize the circulation of the chlorine-containing water phase, when the rhodium content in the upper organic phase is less than or equal to 0.005g/L, the upper organic phase flows into the organic phase collecting unit through the three-way pipe I as a rhodium-poor organic phase, and when the rhodium content in the lower rhodium-containing water phase is not less than 2g/L, the lower rhodium-containing water phase flows into the water phase product collecting unit through the three-way pipe II as a rhodium-rich water phase.
2. 2. The method for transferring rhodium in rhodium-containing organic waste liquid into water phase by two-phase oxidation according to claim 1, wherein the diluent in the step (1) is one or more of isooctane, toluene, methyl isobutyl ketone and ethyl acetate.
3. 3. The method for transferring rhodium in rhodium-containing organic waste liquid to water phase by two-phase oxidation according to claim 1, wherein the rhodium content in the rhodium-containing organic waste liquid pretreated in the step (1) is 100-3000 mg/L.
4. 4. The method for transferring rhodium from rhodium-containing organic waste liquid to aqueous phase by two-phase oxidation according to claim 1, wherein the concentration of hydrochloric acid in the aqueous phase containing chlorine in the step (2) is 4-8 mol/L, and the concentration of soluble chloride is 0.5-2.0 mol/L.
5. 5. The process for the two-phase oxidative transfer of rhodium from a rhodium-containing organic waste liquid to an aqueous phase according to claim 4, wherein the chloride in step (2) is one or more of NaCl, KCl, liCl, mgCl 2 、CaCl 2 、NH 4 Cl.
6. 6. The method for transferring rhodium in rhodium-containing organic waste liquid to aqueous phase by two-phase oxidation according to claim 1, wherein Ag/AgCl is used as a reference electrode, oxidation-reduction potential of in-situ electrolysis in step (3) is 600-950 mV, available chlorine in active chlorine aqueous phase calculated by Cl 2 is 0.5-3 mmol/L, and concentration ratio of free chloride ion to hydrogen ion is 0.1-1.0:1.
7. 7. The method for transferring rhodium in rhodium-containing organic waste liquid to water phase by two-phase oxidation according to claim 1, wherein the volume ratio of the active chlorine water phase to the pretreated rhodium-containing organic waste liquid in the step (3) is 1:1-5, the oxidation-transfer reaction temperature is 35-80 ℃, and the single-stage oxidation-transfer reaction time is 5-15 min.
8. 8. The method for transferring rhodium from rhodium-containing organic waste liquid to water phase by two-phase oxidation according to claim 1, wherein the partial pressure of carbon monoxide gas in the step (3) is 0.3-2.0 bar.

Description

Method for transferring rhodium in rhodium-containing organic waste liquid to water phase through two-phase oxidation Technical Field The invention relates to a method for transferring rhodium in rhodium-containing organic waste liquid to a water phase through two-phase oxidation, belonging to the technical field of precious metal regeneration metallurgy. Background The rhodium-containing organic dead catalyst mainly comes from olefin oxo synthesis, alkylation/carbonylation, selective hydrogenation and other homogeneous systems, and is typically reaction mother liquor, washing liquor and concentrated tar residues of Rh-phosphine (such as triphenylphosphine) -carbonyl complex in solvents such as aromatic hydrocarbon/alkane/ketone and the like. In addition to Rh complex, phosphine/phosphine oxide (such as PPh 3 and TPPO), unreacted substrate, byproduct aldehyde/alcohol/acid, a small amount of polymer and trace inorganic salt are often co-present in the waste liquid, and the physical properties of the waste liquid are high viscosity, easy emulsification and large component fluctuation. Rhodium is used as rare noble metal, the resource endowment is rare, the price is high, the fluctuation of a supply chain is sensitive, the economic value and the strategic value are obvious, and meanwhile, organic components such as phosphine/phosphine oxide and the like have recovery values. If the rhodium is burned or buried at will, not only is the rhodium and the organic ligand greatly lost, but also the environmental burden of volatile organic compounds, chlorine-containing and phosphorus-containing organic compounds and acid tail gas is brought. Therefore, the establishment of the recovery process which is oriented to the complex organic system, can be amplified, controllable and intrinsically safe has direct significance on the cost reduction and synergy of enterprises, the closed cycle of noble metals and the environment compliance. The prior recovery technology can be divided into three types, namely an external reinforcing oxidant-water phase transfer-precipitation/reduction route, namely adding active chlorine or a peroxidation system (such as Cl 2, hypochlorite, chlorate, hydrogen peroxide and the like) into an organic-water two-phase system to increase the valence state of Rh and convert the Rh into a water phase, then enriching the Rh by using precipitation, reduction or ion exchange resin, a physical separation-heat treatment-acid dissolution route, recovering a solvent and a low-boiling organic matter by multistage rectification, incinerating concentrated slag or forming an oxide by high Wen Churong, dissolving and reducing and refining by a strong acid/chlorination system, and a membrane/extraction/absorption combined process, wherein the Rh enrichment is realized by utilizing ceramic ultrafiltration or organic solvent nanofiltration to remove macromolecular tar and matching extraction and resin adsorption. The method can realize rhodium recovery to a certain extent in experiments or engineering, but has the common problems that organic phase side reactions (chlorination and condensation) are easy to cause emulsification and tarry under a strong oxidation environment, incineration/high-temperature ashing and multistage rectification have high energy consumption, rh (0) black colloid or indissolvable oxide is easy to generate at a two-phase interface, transfer/filtration loss is caused, and a large amount of salt-containing mother liquor and solid waste are generated in the repeated cycle process of precipitation reduction. In combination, the prior art either relies on external reinforcing oxidants or on high temperature heat treatment and multiple chemical cycles, and cannot meet the requirements of rapid and clear phase separation, colloid inhibition and continuous operation with low salt load. Disclosure of Invention Aiming at the problems that rhodium recovery in rhodium-containing organic waste liquid depends on external oxidant or depends on high-temperature heat treatment, chemical circulation is repeated and the like in the prior art, the invention provides a method for transferring rhodium in rhodium-containing organic waste liquid to a water phase through two-phase oxidation, wherein an active chloridion organic phase is formed in situ by taking chloridion in the water phase as a source in a two-phase system, and rhodium (0) colloid/rhodium oxide auxiliary phase generation is inhibited by carbon monoxide during oxidation, and rhodium is transferred to the water phase in a synergic manner; the invention obtains stable and treatable rhodium-rich water phase, leaves enough selection space for the subsequent adoption of a conventional wet process, and simultaneously reserves and recycles an organic phase. The two-phase oxidation transfer system comprises a two-phase contact unit and an in-situ active chlorine electrolysis unit, wherein the two-phase contact unit comprises a mixing unit, a phase separation