Harmless treatment method for efficiently removing fluorine ions from copper smelting wastewater

Abstract

The invention relates to the technical field of wastewater treatment, in particular to a harmless treatment method for efficiently removing fluorine ions from copper smelting wastewater, which comprises the following steps: sequentially passing the copper smelting wastewater through a grating and an adjusting tank to remove particle impurities, and introducing the wastewater into the adjusting tank to adjust the wastewater to a preset pH value; introducing the wastewater with the adjusted pH value into a reaction tank, adding calcium salt, stirring the wastewater and the calcium salt, and reacting to generate calcium fluoride precipitate; introducing the wastewater into an adsorption column filled with an adsorbent, and carrying out adsorption treatment on fluorine ions in the wastewater; introducing the wastewater into an ion exchange column filled with fluorine selective ion exchange resin, and removing fluorine ions in the wastewater; sludge generated by chemical precipitation is concentrated and dehydrated, and a curing agent is used for curing the sludge; according to the method, the fluorine ions in the copper smelting wastewater can be deeply removed, the effect of removing the fluorine ions in the copper smelting wastewater is improved, and the concentration of the fluorine ions in the effluent is stably lower than the emission standard.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a method for the efficient removal of fluoride ions from copper smelting wastewater and its harmless treatment. Background Technology

[0002] Copper smelting generates large amounts of wastewater containing high concentrations of fluoride ions. If this wastewater is discharged directly without proper treatment, it will have serious impacts on the environment and ecosystems, including water pollution, soil acidification, and fluoride accumulation in the food chain. Therefore, the efficient removal of fluoride ions and the harmless treatment of copper smelting wastewater are of paramount importance.

[0003] Currently, existing methods for treating copper smelting wastewater cannot effectively remove fluoride ions from the wastewater, resulting in insufficient fluoride ion removal and causing the effluent fluoride concentration to remain consistently below the discharge standards. Summary of the Invention

[0004] The purpose of this invention is to provide a harmless treatment method for the efficient removal of fluoride ions from copper smelting wastewater. This method can deeply remove fluoride ions from copper smelting wastewater, improve the fluoride ion removal effect, and ensure that the fluoride ion concentration in the effluent is consistently lower than the discharge standard.

[0005] To achieve the above objectives, this invention provides a method for the harmless treatment of copper smelting wastewater by efficiently removing fluoride ions, comprising: The copper smelting wastewater is passed through a screen and a regulating tank in sequence to remove particulate impurities. The wastewater is then introduced into the regulating tank to adjust the wastewater to the preset pH value. After the pH value of the wastewater is adjusted, calcium salt is added to the reaction tank. The wastewater and calcium salt are stirred and reacted to form calcium fluoride precipitate. Wastewater is passed through an adsorption column filled with adsorbent, with the flow rate controlled at 2-5 BV / h and the contact time at 30-60 minutes, to adsorb fluoride ions in the wastewater. Wastewater is passed through an ion exchange column filled with fluoride-selective ion exchange resin, with the flow rate controlled at 1-3 BV / h and the contact time at 20-40 minutes to remove fluoride ions from the wastewater. The sludge produced by chemical precipitation is concentrated and dewatered, and then solidified using a solidifying agent. The solidified sludge is then used for building material preparation or safe landfill.

[0006] In one step, copper smelting wastewater is passed sequentially through a screen and a regulating tank to remove particulate impurities. The wastewater is then introduced into the regulating tank to adjust it to a preset pH value. The preset pH value is 7-9.

[0007] In one step, after the pH-adjusted wastewater is introduced into the reaction tank, calcium salt is added, and the wastewater and calcium salt react to form calcium fluoride precipitate. The stirring speed of the wastewater and calcium salt is 200-300 r / min, and the reaction time is 30-60 minutes.

[0008] In one step, wastewater is passed through an adsorption column filled with adsorbent, with a flow rate controlled at 2-5 BV / h and a contact time of 30-60 minutes, to adsorb fluoride ions from the wastewater. The adsorbent is activated alumina or modified zeolite.

[0009] The step of adsorbing fluoride ions in wastewater by passing it through an adsorption column filled with adsorbent, controlling the flow rate at 2-5 BV / h, and the contact time at 30-60 minutes, also includes: The concentration of fluoride ions in the water should be tested regularly, and the adsorbent should be regenerated or replaced when it becomes saturated.

[0010] In one step, wastewater is passed through an ion exchange column filled with fluoride-selective ion exchange resin, with the flow rate controlled at 1-3 BV / h and the contact time at 20-40 minutes, to remove fluoride ions from the wastewater. The fluorine-selective ion exchange resin is an aminophosphate resin.

[0011] The step of passing wastewater through an ion exchange column filled with fluoride-selective ion exchange resin, controlling the flow rate at 1-3 BV / h and the contact time at 20-40 minutes, to remove fluoride ions from the wastewater, also includes: The concentration of fluoride ions in the water is monitored regularly. When the fluoride-selective ion exchange resin becomes saturated, it is regenerated using sodium hydroxide solution.

[0012] This invention discloses a method for the efficient removal and harmless treatment of fluoride ions from copper smelting wastewater. Through the combined application of chemical precipitation, adsorption, and ion exchange processes, it achieves deep removal of fluoride ions from copper smelting wastewater, improving the removal efficiency and ensuring that the effluent fluoride concentration remains consistently below discharge standards. Simultaneously, the method effectively treats and explores the resource utilization of fluoride-containing sludge generated during the chemical precipitation process, preventing secondary fluoride pollution through solidification and other technical means. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below.

[0014] Figure 1 This is a flowchart of a method for the efficient removal of fluoride ions and harmless treatment of copper smelting wastewater according to the present invention. Detailed Implementation

[0015] The embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, but should not be construed as limiting the present invention.

[0016] Please see Figure 1 ,in, Figure 1 This is a flowchart of a method for the efficient removal of fluoride ions and harmless treatment of copper smelting wastewater according to the present invention.

[0017] This invention provides a method for the efficient removal of fluoride ions from copper smelting wastewater and its harmless treatment, comprising: S1 passes the copper smelting wastewater through a screen and a regulating tank in sequence to remove particulate impurities. The wastewater is then introduced into the regulating tank to adjust the wastewater to the preset pH value. In this step, the preset pH value is 7-9.

[0018] Specifically, copper smelting wastewater is first introduced into a screen to intercept larger particulate impurities, such as suspended solids and floating matter, preventing them from clogging or damaging subsequent treatment equipment. Next, the wastewater flows into a regulating tank, where a stirring device homogenizes the wastewater's quality and quantity, and adjusts the pH value to a suitable range, preferably 7-9.

[0019] S2 introduces the pH-adjusted wastewater into the reaction tank and adds calcium salt. After stirring the wastewater and calcium salt, they react to generate calcium fluoride precipitate. In this step, the stirring speed of the wastewater and calcium salt is 200-300 r / min, and the reaction time is 30-60 minutes. Specifically, calcium salt is added to the pretreated wastewater in the reaction tank, utilizing the reaction of calcium ions with fluoride ions to form insoluble calcium fluoride precipitate. During the reaction, the stirring speed and reaction time are controlled to promote a complete reaction; the stirring speed is 200-300 r / min, and the reaction time is 30-60 minutes. Simultaneously, the amount of calcium salt added is calculated and adjusted based on the fluoride ion concentration in the wastewater to improve the fluoride ion removal efficiency. The calcium salt used is, for example, calcium chloride or calcium hydroxide.

[0020] S3 introduces wastewater into an adsorption column filled with adsorbent, controls the flow rate at 2-5 BV / h, and the contact time at 30-60 minutes to adsorb fluoride ions in the wastewater. In this step, the adsorbent used is activated alumina or modified zeolite. This step also includes periodically monitoring the fluoride ion concentration in the effluent, and regenerating or replacing the adsorbent when it becomes saturated.

[0021] Specifically, the wastewater after preliminary defluorination is passed through an adsorption column filled with activated alumina or modified zeolite as the adsorbent. The flow rate of the adsorption column is controlled at 2-5 BV / h, and the contact time is 30-60 minutes to ensure sufficient adsorption of fluoride ions. The fluoride ion concentration in the effluent is monitored periodically, and the adsorbent is regenerated or replaced when it becomes saturated. The specific steps for periodically monitoring the effluent fluoride ion concentration and regenerating or replacing the adsorbent when it becomes saturated are as follows: an automatic sampler is installed at the outlet of the adsorption column to collect water samples at fixed time intervals T, where T is 2-4 hours; the collected water samples are filtered through a 0.45μm microporous membrane, and the fluoride ion concentration Ct is determined using the fluoride ion selective electrode method, in mg / L; for the adsorption column, the detected concentration is compared with a preset adsorbent saturation concentration limit. When the detected concentration is greater than the preset adsorbent saturation concentration limit, the adsorbent is considered saturated and regenerated or replaced.

[0022] S4 involves passing wastewater through an ion exchange column filled with fluoride-selective ion exchange resin, controlling the flow rate at 1-3 BV / h and the contact time at 20-40 minutes to remove fluoride ions from the wastewater. In this step, the fluoride-selective ion exchange resin used is an aminophosphate resin. This step also includes: periodically monitoring the fluoride ion concentration in the effluent; and regenerating the fluoride-selective ion exchange resin using a sodium hydroxide solution once it becomes saturated.

[0023] Specifically, the adsorbed wastewater is passed through an ion exchange column filled with a fluoride-selective resin (such as aminophosphate resin). The flow rate of the ion exchange column is controlled at 1-3 BV / h, and the contact time is 20-40 minutes to ensure efficient removal of fluoride ions. The fluoride ion concentration in the effluent is monitored periodically. When the resin is saturated, it is regenerated using sodium hydroxide solution. The specific steps for periodically monitoring the effluent fluoride ion concentration and regenerating the fluoride-selective ion exchange resin with sodium hydroxide solution after saturation are as follows: An automatic sampler is installed at the outlet of the ion exchange column to collect water samples at fixed time intervals T, where T is 2-4 hours. The collected water samples are filtered through a 0.45μm microporous membrane, and the fluoride ion concentration is determined using the fluoride ion selective electrode method, in mg / L. For the ion exchange column, the detected concentration is compared with a preset resin saturation concentration limit. When the detected concentration is greater than the preset resin saturation concentration limit, the fluoride-selective ion exchange resin is determined to be saturated, and regeneration of the fluoride-selective ion exchange resin is performed using sodium hydroxide solution.

[0024] S5 concentrates and dewaters the sludge produced by chemical precipitation, and uses a solidifying agent to solidify the sludge. The solidified sludge is then used for building material preparation or safe landfill. Specifically, the sludge produced by chemical precipitation is concentrated and dewatered to reduce its moisture content. A solidifying agent (such as cement or lime) is used to solidify the sludge to prevent fluoride ion leaching. The solidified sludge is then used for building material production (such as brick making and road paving) or safely landfilled.

[0025] This invention discloses a method for the efficient removal and harmless treatment of fluoride ions from copper smelting wastewater. Through the combined application of chemical precipitation, adsorption, and ion exchange processes, it achieves deep removal of fluoride ions from copper smelting wastewater, improving the removal efficiency and ensuring that the effluent fluoride concentration remains consistently below discharge standards. Simultaneously, the method effectively treats and explores the resource utilization of fluoride-containing sludge generated during the chemical precipitation process, preventing secondary fluoride pollution through solidification and other technical means.

[0026] The above-disclosed embodiments are merely one or more preferred embodiments of this application and should not be construed as limiting the scope of this application. Those skilled in the art can understand that all or part of the processes for implementing the above embodiments and equivalent changes made in accordance with the claims of this application still fall within the scope of this application.

Claims

1. A method for the harmless treatment of copper smelting wastewater with efficient removal of fluoride ions, characterized in that, include: The copper smelting wastewater is passed through a screen and a regulating tank in sequence to remove particulate impurities. The wastewater is then introduced into the regulating tank to adjust the wastewater to the preset pH value. After the pH value of the wastewater is adjusted, calcium salt is added to the reaction tank. The wastewater and calcium salt are stirred and reacted to form calcium fluoride precipitate. Wastewater is passed through an adsorption column filled with adsorbent, with the flow rate controlled at 2-5 BV / h and the contact time at 30-60 minutes, to adsorb fluoride ions in the wastewater. Wastewater is passed through an ion exchange column filled with fluoride-selective ion exchange resin, with the flow rate controlled at 1-3 BV / h and the contact time at 20-40 minutes to remove fluoride ions from the wastewater. The sludge produced by chemical precipitation is concentrated and dewatered, and then solidified using a solidifying agent. The solidified sludge is then used for building material preparation or safe landfill.

2. The method for the efficient removal of fluoride ions and harmless treatment of copper smelting wastewater as described in claim 1, characterized in that, In the process of passing copper smelting wastewater through a screen and a regulating tank to remove particulate impurities, the wastewater is then introduced into the regulating tank to adjust the pH value to a preset level. The preset pH value is 7-9.

3. The method for the efficient removal of fluoride ions and harmless treatment of copper smelting wastewater as described in claim 2, characterized in that, In the step of introducing pH-adjusted wastewater into a reaction tank and adding calcium salt, the wastewater and calcium salt are stirred and reacted to form calcium fluoride precipitate. The stirring speed of the wastewater and calcium salt is 200-300 r / min, and the reaction time is 30-60 minutes.

4. The method for the efficient removal of fluoride ions and harmless treatment of copper smelting wastewater as described in claim 3, characterized in that, In the step of adsorbing fluoride ions in wastewater by passing the wastewater through an adsorption column filled with adsorbent, controlling the flow rate at 2-5 BV / h, and the contact time at 30-60 minutes,... The adsorbent is activated alumina or modified zeolite.

5. The method for the efficient removal of fluoride ions and harmless treatment of copper smelting wastewater as described in claim 4, characterized in that, The step of adsorbing fluoride ions in wastewater by passing the wastewater through an adsorption column filled with adsorbent, controlling the flow rate at 2-5 BV / h, and the contact time at 30-60 minutes, also includes: The concentration of fluoride ions in the water should be tested regularly, and the adsorbent should be regenerated or replaced when it becomes saturated.

6. The method for the efficient removal of fluoride ions and harmless treatment of copper smelting wastewater as described in claim 5, characterized in that, In the step of removing fluoride ions from wastewater, the wastewater is passed through an ion exchange column filled with fluoride-selective ion exchange resin, with the flow rate controlled at 1-3 BV / h and the contact time at 20-40 minutes. The fluorine-selective ion exchange resin is an aminophosphate resin.

7. The method for the efficient removal of fluoride ions and harmless treatment of copper smelting wastewater as described in claim 6, characterized in that, The process of passing wastewater through an ion exchange column filled with fluoride-selective ion exchange resin, controlling the flow rate at 1-3 BV / h and the contact time at 20-40 minutes, also includes: The concentration of fluoride ions in the water is monitored regularly. When the fluoride-selective ion exchange resin becomes saturated, it is regenerated using sodium hydroxide solution.

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