CN-122010345-A - Copper-containing cyanide-containing wastewater cooperative treatment and copper recycling recovery method

Abstract

The copper-containing cyanide-containing wastewater cooperative treatment and copper recycling recovery method comprises the steps and conditions of pretreatment adjustment, iron-carbon micro-electrolysis vein breaking pretreatment, copper precipitation reaction and solid-liquid separation, copper recycling recovery, and active carbon catalytic oxidation cyanide removal and standard emission cooperative combination, and particularly comprises five steps and conditions, so that the standard emission of cyanide removal and copper-containing cyanide-containing wastewater is achieved, and the method has the advantages of solving the problems of poor cooperativity, incomplete copper recovery, easy poisoning of active carbon, high operation cost and the like of the conventional technology, and achieving the treatment targets of high efficiency, low cost and recycling.

Inventors

• ZHANG YAOMING
• LIU QIANG
• WANG HONGJUN
• GAO SHIKANG
• WANG QIANKUN
• SUN ZHONGMEI
• WU ZENGLING
• HE YUANPENG

Assignees

• 紫金矿业集团股份有限公司

Dates

Publication Date

20260512

Application Date

20260317

Claims (5)

1. 1. The copper-containing cyanide-containing wastewater cooperative treatment and copper recycling recovery method is characterized by combining pretreatment adjustment, iron-carbon micro-electrolysis vein breaking pretreatment, copper precipitation reaction and solid-liquid separation, copper recycling recovery, active carbon catalytic oxidation cyanide removal and standard emission cooperative combination process, and specifically comprises the following process steps and conditions: (1) The pretreatment and adjustment are carried out, namely, the wastewater containing copper and cyanide is filtered by a grid to remove suspended matters and impurities with the particle size of more than or equal to 5mm, the water quality of the wastewater is detected, the total cyanide concentration of the inflow water is controlled to be 50-500 mg/L, the copper ion concentration is controlled to be 5-100 mg/L, COD to be less than or equal to 2000mg/L, and if the pH value of the wastewater is more than 8, dilute sulfuric acid with the mass fraction of 10-20% is added to adjust the pH value to be 4.0-8.0 for standby; (2) Pumping the wastewater regulated in the step (1) into an iron-carbon micro-electrolysis reactor, filling iron-carbon composite filler in the reactor, controlling the mass ratio of iron to carbon in the iron-carbon composite filler to be 4:1-6:1, controlling the particle size of the filler to be 3-8 mm, the porosity to be 40-50%, and the ratio of the filler layer height to the reactor diameter to be 3:1-4:1, introducing air into the reactor for aeration treatment, adjusting the aeration intensity to be 1.0-1.5 m < 3 >/(m < 3 >. H), reacting for 60-120 min, and generating Fe2+ by using an iron-carbon primary cell reaction, wherein the anode Fe loses electrons, and the cathode generates hydrogen evolution reaction to generate a reduced state [ H ], and the Fe2+ and [ H ] synergistically destroy Cu-CN complex bonds, converting the complex state copper into free state Cu < 2+ >, and simultaneously, adsorbing part of colloid cyanide and organic matters by Fe (OH) 2 /Fe(OH) 3 flocs generated in the reaction process, and synchronously removing free cyanide to reduce COD load; (3) Slowly adding alkali solution into the broken wastewater obtained in the step (2), wherein the alkali solution is 10-20% of sodium hydroxide solution or calcium hydroxide solution by mass fraction, continuously stirring in the adding process, adjusting the pH value of the wastewater to 8.5-9.5, maintaining the stirring speed to 50-80 r/min, reacting for 30-45 min, fully reacting free Cu < 2+ > with OH < - >, generating copper hydroxide precipitate, reacting residual Fe < 3+ > with OH < - >, generating ferric hydroxide precipitate, after the reaction is finished, sending the mixed solution into the precipitate Chi Jingzhi for precipitating for 60-90 min, and carrying out solid-liquid separation to obtain mixed precipitate slag and supernatant containing copper hydroxide and ferric hydroxide; (4) Copper recycling recovery, namely transferring the mixed precipitate slag obtained in the step (3) into an acid solution tank, adding 15-25% of dilute sulfuric acid by mass fraction, regulating the pH value of a reaction system to 2.0-2.5, maintaining the temperature at 40-50 ℃, stirring and reacting for 40-60 min to completely dissolve the mixed precipitate slag to obtain a mixed sulfate solution containing Cu < 2+ > and Fe < 3+ >, slowly adding 30% of hydrogen peroxide by mass fraction into the mixed sulfate solution, oxidizing the residual Fe < 2+ > into Fe < 3+ >, finely regulating the pH value to 2.8-3.2 by using 10% of sodium hydroxide solution by mass fraction, stirring and reacting at constant temperature at 40 ℃ for 30min to completely hydrolyze Fe < 3+ > to generate ferric hydroxide precipitate, standing and precipitating for 20-30 min, and filtering to remove the ferric hydroxide precipitate to obtain a pure copper sulfate solution, carrying out electrolytic treatment on the pure copper sulfate solution by adopting an electrolytic deposition method, controlling the electrolytic voltage to be 1.8-2.2V, the electrolytic current density to be 20-30 mA/cm < 2 >, the electrolytic temperature to be 30-40 ℃, and the electrolytic time to be 120-180 min, separating out metal copper by a cathode, and obtaining an industrial grade copper product after washing and drying; (5) The method comprises the steps of (1) feeding supernatant obtained in the step (3) into an active carbon catalytic oxidation reactor, filling a granular active carbon catalyst loaded with iron and copper double metal ions in the reactor, wherein the specific surface area of the catalyst is 800-1200 m <2 >/g, the total loading amount of the iron and copper metal ions is 3% -5% of the mass of the active carbon, preparing the catalyst by an impregnation method, drying and activating, introducing air into the reactor for aeration, controlling the aeration intensity to be 0.8-1.2 m < 3 >/(m < 3 >. H), maintaining the reaction temperature to be 25-30℃, pH to be the original pH value of the supernatant, and the retention time of wastewater to be 90-120 min, and utilizing the catalytic activity of the active carbon and the double metal ions, combining aeration oxygen supply to oxidatively decompose residual cyanide into harmless substances, synchronously adsorbing and degrading part of residual organic matters and trace heavy metal ions, thereby realizing the standard discharge of the wastewater.
2. 2. The method of claim 1, wherein the iron-carbon composite filler in the step (2) can be repeatedly used for 3-5 treatment cycles, and after the filler fails, the filler is subjected to acid washing and activation for 30-40 min by 5% -8% dilute sulfuric acid, so that passivation films and impurities attached to the surface are removed, and the filler can be reused after being washed to be neutral.
3. 3. The method according to claim 1 or 2, wherein the waste liquid containing trace iron ions generated by the acid washing in the step (2) is collected to the acid dissolution tank in the step (4) for recycling.
4. 4. The method according to claim 1, wherein the electrolytic deposition method in the step (4) uses a titanium ruthenium-plated electrode as an anode and a pure copper sheet as a cathode, and the surface attachments of the electrode are cleaned periodically during the electrolytic process to keep the electrolytic efficiency stable.
5. 5. The method according to claim 1 or 4, wherein the electrolyte after the electrolytic deposition in the step (4) is returned to the pretreatment regulating unit of the step (1) for recycling.

Description

Copper-containing cyanide-containing wastewater cooperative treatment and copper recycling recovery method Technical Field The invention relates to the technical field of industrial wastewater treatment and recycling recovery, in particular to a copper-containing cyanide-containing wastewater cooperative treatment and copper recycling recovery method. Background The cyanide-containing wastewater containing copper is a typical pollutant in industries such as electroplating, metallurgy, gold cyanide leaching and the like, and the cyanide in the wastewater mostly exists in a free state (CN-) and a complex state (such as Cu (CN) 3²⁻、Cu(CN)4 & lt- & gt), and copper ions mainly form a stable complex with cyanide, so that the cyanide-containing wastewater has the characteristics of strong toxicity, difficult degradation and complex pollutant components. If the waste water is directly discharged, serious harm is caused to the ecological environment and human health, and meanwhile, copper resources in the waste water are not recovered, so that resource waste is caused. At present, the treatment method of copper-containing cyanide-containing wastewater mainly comprises two major types of cyanide degradation and copper resource recovery, but the prior art generally has the problems of poor cooperativity, high treatment cost, unstable effect and the like, and is characterized in that (1) an oxidation method (such as an alkaline chlorination method and an ozone oxidation method) can degrade cyanide, but copper resources cannot be effectively recovered, and has limited degradation efficiency on complex cyanide, toxic intermediate products are easy to generate, equipment investment and operation cost are higher, (2) a precipitation method (such as a copper salt precipitation method) can remove part of cyanide, but the medicament consumption is huge, the generated copper-containing precipitate is mostly treated as dangerous waste, the recycling utilization rate is low, cyanide standard emission is difficult to realize synchronously, and (3) a single iron-carbon micro-electrolysis process can destroy part of complex bonds and remove free cyanide, but cannot degrade stable complex cyanide, the total cyanide concentration of treated effluent is still higher, and copper resources are not recovered, and copper ions of iron-carbon effluent residues can be poisoned and then deeply treated, and (4) an active carbon catalytic oxidation method can deeply remove cyanide, but the catalytic efficiency of the copper ions in the copper-containing cyanide is easy to be directly polluted, and the catalytic life of the raw water is greatly shortened if the catalytic activity and the activity cost of the raw water is greatly shortened is required to be greatly shortened. In the prior art, the cyanide treatment and the copper resource recovery are mostly independent procedures, and the problems that the treatment effect, the resource recovery and the cost control cannot be considered exist. In order to solve the problems, CN102079590B ' a method for treating and recycling copper-cyanide complex wastewater ', which is disclosed by the invention, is characterized in that simple substance aluminum or simple substance phosphorus is adopted as a reducing agent, and the copper-cyanide complex wastewater is stirred and reacted for 1-5 hours and then subjected to solid-liquid separation to realize wastewater recycling and copper recovery, but the reducing agent adopts simple substance aluminum/phosphorus, secondary impurities are easily generated in the reaction process, a targeted complex cyanide breaking mechanism is not established, the treatment effect on a stable Cu-CN complex is limited, and no chemical agent circulation and sludge recycling design are adopted, so that a closed-loop treatment process cannot be formed; the invention adopts a two-step method of ' ion recovery and extraction separation ' to treat the copper cyanide-containing wastewater, firstly carries out security filtration and impurity removal, then enriches cyanide complex and free cyanide through a cyanide ion recoverer to obtain analysis concentrated solution, then fills inert gas into a sealed tank, adds sulfuric acid and sodium chloride mixed extractant, separates and recovers finished products of hydrogen cyanide and cuprous chloride to realize separate recovery of cyanide and copper, but relies on a sulfuric acid-sodium chloride extraction system, the consumption and the loss of extractant are larger, no reagent circulation multiplexing design exists, the treatment cost is higher, the influence on the stable Cu-CN complex is obvious due to the influence of the complex state content, the copper resource recovery form is cuprous chloride, the application scene is limited, general industrial grade copper product cannot be directly produced, the inert gas is added and the hydrogen cyanide is collected, the operation complexity and the risk of the large-scale application are