Method for synergistic control and removal of organic matters in a zinc hydrometallurgy process

Abstract

This invention discloses a method for the synergistic control and removal of organic matter in the hydrometallurgical process of zinc smelting, belonging to the field of hydrometallurgical technology. It includes the following steps: incorporating the TOC content of manganese ore powder and iron removal agent into quality monitoring and limiting content thresholds; controlling the addition amounts of flocculant, bone glue, and organic cobalt removal agent; and simultaneously adjusting the concentrations of zinc ions and soluble silicon in the supernatant to reduce liquid viscosity, thereby reducing the introduction of impurities at the source; adding activated carbon to the purification process to adsorb organic matter; and adding a waste liquid circulation filtration system to the electrolysis process, while selectively adding modified activated carbon to remove suspended solids, organic matter, colloids, and harmful impurity ions from the electrolytic waste liquid. This invention achieves three main benefits: first, it establishes a synergistic removal system for fine suspended solids, colloids, organic matter, and impurity ions; second, it increases the electrolysis current efficiency to over 90% and reduces cell voltage; and third, it improves the utilization efficiency of fresh liquid and reduces overall production costs.

Description

Technical Field

[0001] This invention relates to the field of hydrometallurgical technology, specifically to a method for the synergistic control and removal of organic matter during the hydrometallurgical zinc smelting process. Background Technology

[0002] In the electrolytic deposition process of hydrometallurgical zinc refining, the fresh solution from the leaching and purification processes typically contains residual suspended solids (such as colloids and anode mud), trace amounts of incompletely precipitated impurity ions (such as iron, copper, cobalt, germanium, fluorine, and chlorine), and soluble or microemulsified organic matter. The presence of these impurities poses the following significant hazards to the zinc electrolysis process: Affecting the quality of cathode zinc: Suspended matter adhering to or being trapped on the cathode surface causes pitting, burning, and granulation on the zinc sheet; its accumulation in the electrolytic cell will increase resistivity, raise the cell temperature, and reduce current efficiency.

[0003] Increased cell voltage and energy consumption: Organic matter adsorbs and decomposes at the cathode, forming a barrier film that hinders zinc reduction; impurity ions trigger side reactions and synergistic discharges, leading to increased ineffective power consumption.

[0004] Decreased current efficiency and new electrolyte utilization: The intensified hydrogen evolution side reaction leads to a decrease in current efficiency; the accelerated accumulation of impurities forces frequent high-flow-rate electrolyte replacement, reducing the utilization efficiency of new electrolyte.

[0005] Existing organic matter removal technologies in hydrometallurgical zinc smelting processes have the following problems: Traditional hydrometallurgical zinc plants commonly use activated carbon to adsorb organic matter during the leaching and purification processes, but this method has significant drawbacks: the leaching and purification processes involve high system temperatures, low liquid viscosity, high organic matter solubility, and low removal efficiency. Unremoved impurity ions, colloids, and organic matter precipitate and agglomerate in large quantities after cooling during the electrolysis process, inducing problems such as plate burning, a sharp drop in current efficiency, and substandard cathode zinc quality. Summary of the Invention

[0006] The purpose of this invention is to provide a method for the synergistic control and removal of organic matter in the hydrometallurgical zinc smelting process. The core of this method lies in: firstly, establishing a synergistic removal system for fine suspended solids, colloids, organic matter, and impurity ions; secondly, increasing the electrolysis current efficiency to over 90% and reducing the cell voltage; and thirdly, improving the utilization efficiency of the fresh solution and reducing overall production costs.

[0007] A method for the synergistic control and removal of organic matter in a hydrometallurgical zinc smelting process includes the following steps: Step 1: Source Control The TOC content of manganese ore powder and iron removal agent is included in quality monitoring and the content threshold is limited. The amount of flocculant, bone glue and organic cobalt removal agent added is controlled. At the same time, the concentration of zinc ions and soluble silicon in the middle and upper rinsing is adjusted to reduce the viscosity of the liquid. The introduction of impurities is reduced from the source. The acidity of waste electrolyte and the temperature of the electrolytic cell are reasonably controlled. Step Two: Deep Purification Activated carbon is added to the purification process to adsorb organic matter; a waste liquid circulation filtration system is added to the electrolysis process, and modified activated carbon is selectively added to remove suspended solids, organic matter, colloids and harmful impurity ions from the electrolytic waste liquid. Step 3: Resource Recycling The filtrate after deep purification is returned to the mixing tank of the electrolysis process and mixed with the new liquid in a certain proportion to form an electrolyte, which is then sent to the electrolysis cell. The waste residue generated from deep purification is transported to the roasting process or slag treatment process for pyrometallurgical treatment to recover valuable metals from the slag.

[0008] Furthermore, in the source control process described in step one, the TOC content of manganese ore powder / iron removal agent is limited to <0.1%; the amount of flocculant added is <0.6 kg / t.Zn, the amount of bone glue added is <0.4 kg / t.Zn, and the amount of organic cobalt removal agent added is <5.5 kg / t.Zn; the concentration of zinc ions in the middle and upper clarifiers is controlled within 150 g / L, and the concentration of soluble silicon is controlled within 80 mg / L.

[0009] Furthermore, activated carbon is added to the purification process to adsorb organic matter, and a waste liquid circulation filtration system is added to the electrolysis process, with denser filter cloth used to improve filtration efficiency; at the same time, modified activated carbon is selectively added to deeply remove impurity ions from the electrolytic waste liquid.

[0010] Furthermore, the activated carbon added in the purification process has a particle size of -200 mesh and an addition amount of 0.1–0.2 kg / m³. 3 .

[0011] Furthermore, the acidity of the waste electrolyte in the electrolysis system is controlled within 175 g / L, and the temperature of the electrolytic cell is controlled within 40℃ to avoid the impurities from burning the plate due to excessively high cell temperature, thus ensuring the quality of zinc deposition at the cathode and stabilizing production.

[0012] In summary, due to the adoption of the above technical solution, the beneficial effects of the present invention are: 1. The waste liquid filtration of this invention exhibits excellent removal effects on various harmful impurity ions. In particular, it significantly reduces the concentration of ions such as copper (Cu), cobalt (Co), iron (Fe), and cadmium (Cd), which are extremely sensitive to the electrodeposition process, effectively reducing the risk of impurity ions burning the plate and creating favorable conditions for improving current efficiency.

[0013] 2. After filtration, the total organic carbon (TOC) content in the waste liquid of this invention is reduced from a relatively high level before filtration (about 180 mg / L) to about 60 mg / L, with a removal rate of up to 64.85%. This effectively inhibits the problem of excessive accumulation of organic matter in the electrolyte and reduces the probability of organic matter burning the plates in the electrolysis system.

[0014] 3. This invention reduces the content of impurities such as organic matter and suspended anode mud in the electrolyte by filtering the waste liquid. The conductivity of the waste liquid before and after filtration is increased by 1.1 mS / cm, which means that the cell voltage can be reduced by about 0.08V and the DC power consumption of the cathode zinc can be reduced by about 60 kWh / t.Zn. While reducing the impurity content, it is also conducive to stable and efficient electrolytic production.

[0015] 4. This invention can make the cathode zinc surface denser, smoother, and flatter, significantly reducing pitting, granulation, and burnt plate phenomena, and significantly improving the grade rate.

[0016] 5. This invention has significant environmental benefits. The amount of acid mist generated by the decomposition of organic matter and hydrogen evolution during the electrolysis production process is significantly reduced, and harmful impurities are enriched in the filter residue, which facilitates the centralized recovery of valuable metals and harmless disposal. Detailed Implementation

[0017] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to embodiments.

[0018] Example 1 This embodiment specifically provides a method for the synergistic control and removal of organic matter during the hydrometallurgical zinc smelting process, including the following steps: Step 1: Control the TOC content of auxiliary materials such as manganese powder and iron removal agent to <0.1%; Step 2: The leaching system is controlled to maintain a neutral leaching pH of 5.0. The iron concentration in the supernatant after alum precipitation (the iron ion concentration in the supernatant after the alum precipitation process) is 5 g / L. The Zn concentration in the middle and upper leaches is... 2+ (After the intermediate leaching process is completed, the zinc ion concentration in the intermediate leaching supernatant obtained by solid-liquid separation) is controlled within 150 g / L, the soluble silicon concentration is controlled within 100 mg / L, and the flocculant addition is controlled within 0.6 kg / t.Zn. Step 3: Add activated carbon to the purification system to adsorb organic matter. The activated carbon particle size is -200 mesh, and the addition amount is approximately 0.1 kg / m³. 3 The amount of organic cobalt removal agent added should be controlled within 5.5 kg / t Zn; Step 4: The acidity of the waste electrolyte in the electrolysis system should be below 175g / L, and the temperature of the electrolysis cell should be controlled below 40℃ to avoid excessively high temperature, which can easily cause impurities to burn the plates. The amount of bone glue added should be controlled below 0.4kg / t.Zn. Step 5: Add a waste liquid circulation filtration system to the electrolysis process, using denser filter cloth to improve filtration efficiency. Simultaneously, selectively add modified powdered or granular activated carbon with high specific surface area and optimized pore size distribution (rich in micropores) to deeply remove suspended solids, organic matter, colloids, and harmful impurity ions from the electrolytic waste liquid. The filtrate is returned to the mixing tank of the electrolysis process and mixed with the fresh liquid in a certain proportion to form the electrolyte, which then enters the electrolytic cell. TOC decreases by 60%, cell voltage decreases by 0.08V, and cathode zinc DC power consumption decreases by 40 kWh / t.Zn.

[0019] Step Six: The filter residue is transported to the roasting process or slag treatment process for batching and processing to recover valuable metals from the residue.

[0020] The technical effects achieved by this embodiment are as follows: As shown in the table above, filtration of electrolytic waste liquid exhibits excellent removal effects on various harmful impurity ions. In particular, the concentrations of ions such as copper (Cu), cobalt (Co), iron (Fe), and cadmium (Cd), which are extremely sensitive to the electrodeposition process, are significantly reduced, effectively lowering the risk of impurity ion burn-out and creating favorable conditions for improving current efficiency. After filtration, the total organic carbon (TOC) content in the waste liquid is reduced from a relatively high level before filtration (approximately 180 mg / L) to around 60 mg / L, with a removal rate as high as 64.85%. This effectively inhibits the problem of excessive accumulation of organic matter in the electrolyte and reduces the probability of organic matter burn-out in the electrolysis workshop. By reducing the content of impurities such as organic matter and suspended anode sludge in the electrolyte through waste liquid filtration, the conductivity of the waste liquid increases by 1.1 mS / cm before and after filtration, meaning the cell voltage can be reduced by approximately 0.08 V, and the DC power consumption of the cathode zinc can be reduced by approximately 60 kWh / t.Zn. While reducing impurity content, this also contributes to stable and efficient electrolysis production.

[0021] Example 2 This embodiment specifically provides a method for the synergistic control and removal of organic matter during the hydrometallurgical zinc smelting process, including the following steps: Step 1: Control the TOC content of auxiliary materials such as manganese powder and iron removal agent to <0.2%; Step 2: The leaching system is controlled to maintain a neutral leaching pH of 5.1, with the supernatant iron concentration at 5.2 g / L and the middle and upper leaching Zn concentration at 5.2 g / L. 2+ The concentration of flocculant should be controlled below 145 g / L, the concentration of soluble silica below 80 mg / L, and the flocculant addition rate controlled at 0.6 kg / m³. 3 Within.

[0022] Step 3: Add activated carbon to the purification system to adsorb organic matter. The activated carbon particle size is -200 mesh, and the addition amount is about 0.15 kg / m³. The addition amount of organic cobalt removal agent is controlled within 5.8 kg t. Zn.

[0023] Step 4: The acidity of the waste electrolyte in the electrolysis system should be below 175g / L, and the temperature of the electrolysis cell should be controlled below 40℃ to avoid excessively high temperature, which can easily cause impurities to burn the plates. The amount of bone glue added should be controlled below 0.4kg / t.Zn. Step 5: Add filtration of the electrolytic waste liquid in the electrolysis process, using denser filter cloth to improve filtration efficiency. Simultaneously, selectively add modified powdered or granular activated carbon with high specific surface area and optimized pore size distribution (rich in micropores) to deeply remove suspended solids, organic matter, colloids, and harmful impurity ions from the electrolytic waste liquid. The filtrate is returned to the mixing tank of the electrolysis process and mixed with the fresh liquid in a certain proportion to form the electrolyte, which then enters the electrolytic cell. TOC decreases by 55%, cell voltage decreases by 0.06V, and the cathode zinc DC power consumption decreases by 32 kWh / t.Zn.

[0024] Step Six: The filter residue is transported to the roasting process or slag treatment process for batching and processing to recover valuable metals from the residue.

[0025] Example 3 This embodiment specifically provides a method for the synergistic control and removal of organic matter during the hydrometallurgical zinc smelting process, including the following steps: Step 1: Control the TOC content of auxiliary materials such as manganese powder and iron removal agent to <0.15%; Step 2: The leaching system was controlled with the pH at 5.2 during the intermediate leaching stage, the iron concentration in the supernatant of the alum precipitation was 5.5 g / L, and the zinc concentration in the middle and upper leaching stages was [not specified]. 2+ The concentration of zinc should be controlled within 148 g / L, the concentration of soluble silica within 80 mg / L, and the amount of flocculant added within 0.5 kg / t.Zn.

[0026] Step 3: Add activated carbon to the purification system to adsorb organic matter. The activated carbon particle size is -200 mesh, and the addition amount is approximately 0.2 kg / m³. 3 The amount of organic cobalt removal agent added should be controlled within 5.6 kg / t Zn.

[0027] Step 4: The acidity of the waste electrolyte in the electrolysis system should be below 175g / L, and the temperature of the electrolysis cell should be controlled below 40℃ to avoid excessively high temperature, which can easily cause impurities to burn the plates. The amount of bone glue added should be controlled below 0.3kg / t.Zn. Step 5: Add filtration of the electrolytic waste liquid in the electrolysis process, using denser filter cloth to improve filtration efficiency. Simultaneously, selectively add modified powdered or granular activated carbon with high specific surface area and optimized pore size distribution (rich in micropores) to deeply remove suspended solids, organic matter, colloids, and harmful impurity ions from the electrolytic waste liquid. The filtrate is returned to the mixing tank of the electrolysis process and mixed with the fresh liquid in a certain proportion to form the electrolyte, which then enters the electrolytic cell. TOC decreases by 58%, cell voltage decreases by 0.05V, and the DC power consumption of the cathode zinc decreases by 36 kWh / t.Zn.

[0028] Step Six: The filter residue is transported to the roasting process or slag treatment process for batching and processing to recover valuable metals from the residue.

Claims

1. A method for the synergistic control and removal of organic matter in a hydrometallurgical zinc smelting process, characterized in that, Includes the following steps: Step 1: Source Control The TOC content of manganese ore powder and iron removal agent is included in quality monitoring and the content threshold is limited. The amount of flocculant, bone glue and organic cobalt removal agent added is controlled. At the same time, the concentration of zinc ions and soluble silicon in the middle and upper rinsing is adjusted to reduce the viscosity of the liquid. The introduction of impurities is reduced from the source. The acidity of waste electrolyte and the temperature of the electrolytic cell are reasonably controlled. Step Two: Deep Purification Activated carbon is added to the purification process to adsorb organic matter; a waste liquid circulation filtration system is added to the electrolysis process, and modified activated carbon is selectively added to deeply remove suspended solids, organic matter, colloids and harmful impurity ions from the electrolytic waste liquid; Step 3: Resource Recycling The filtrate after deep purification is returned to the mixing tank of the electrolysis process and mixed with the new liquid in a certain proportion to form an electrolyte, which is then sent to the electrolysis cell. The waste residue generated from deep purification is transported to the roasting process or slag treatment process for pyrometallurgical treatment to recover valuable metals from the slag.

2. The method for synergistic control and removal of organic matter in a hydrometallurgical zinc smelting process according to claim 1, characterized in that, In the source control process described in Step 1, the TOC content of manganese ore powder / iron removal agent is limited to <0.1%; the amount of flocculant added is <0.6 kg / t.Zn, the amount of bone glue added is <0.4 kg / t.Zn, and the amount of organic cobalt removal agent added is <5.5 kg / t.Zn; the concentration of zinc ions in the middle and upper purlins is controlled within 150 g / L, and the concentration of soluble silicon is controlled within 80 mg / L.

3. The method for synergistic control and removal of organic matter in a hydrometallurgical zinc smelting process according to claim 1, characterized in that, In the deep purification process described in step two, activated carbon is added to adsorb organic matter in the purification process, and a waste liquid circulation filtration system is added in the electrolysis process, with denser filter cloth used to improve filtration efficiency; at the same time, modified activated carbon is selectively added to deeply remove impurity ions from the electrolytic waste liquid.

4. The method for synergistic control and removal of organic matter in a hydrometallurgical zinc smelting process according to claim 3, characterized in that, The activated carbon added in the purification process has a particle size of -200 mesh and an addition amount of 0.1–0.2 kg / m³. 3 .

5. The method for synergistic control and removal of organic matter in a hydrometallurgical zinc smelting process according to claim 1, characterized in that, In step one, the acidity of the waste electrolyte in the electrolysis system is controlled within 175 g / L, and the temperature of the electrolytic cell is controlled within 40℃.

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