Method for treating smelting waste acid wastewater with activated sulfur concentrate

Abstract

The present invention relates to the technical field of treatment of smelting wastewater. Disclosed is a method for treating smelting waste acid wastewater with activated sulfur concentrate. The method comprises drying and grinding sulfur concentrate and washing the sulfur concentrate twice with pure water and twice with anhydrous ethanol; uniformly mixing sulfur concentrate powder with Na2S powder at a mass ratio of 10:1-2, adding pure water at the mass-to-volume ratio of the mixed powder to the pure water being 400-500 g:1000 mL, and reacting the mixture for 3.5-4.5 h at 105-115°C, 0.3-0.5 MPa and 160-200 r / min; filtering the resulting activated sulfur concentrate and performing ventilation standing, drying, and grinding; adding lime milk to the wastewater and adjusting the pH value to 2.0-4.0; adding at a ratio of the activated sulfur concentrate powder to the wastewater of 12.0-20.0 g:1.0 L, carrying out ultrasonic treatment at 25-28 kHz, while maintaining the water temperature at 28-32°C, stirring and reacting for 5-6 h at a rotation speed of 140-180 r / min, and maintaining the dissolved oxygen content at 10.0-15.0 mg / L; and after 30-60 minutes of precipitation, adding lime milk to a primary supernatant, adjusting the pH value to 8.0-9.0, continuing to precipitate for 30-60 minutes, and then separating the supernatant obtained again. The method has high water quality applicability, and involves short process flow and low operation cost, the pollutant content of the treated water reaches national standard requirements, and a sediment has good dewatering performance and can be recycled.

Description

A method for treating smelting acid wastewater by activating sulfur concentrate Technical Field

[0001] The invention belongs to the technical field of smelting wastewater treatment, and particularly relates to a method for treating smelting acid wastewater by activating sulfur concentrate. Background Art

[0002] Acid-making workshops for smelting flue gas from copper, lead, zinc and other smelters will produce a large amount of polluted acid wastewater, which has the characteristics of high acidity, high concentration of heavy metals and fluorine, complex composition, large volatility and high toxicity. Therefore, polluted acid is the most difficult to treat among all smelting wastewaters. At present, the main methods for treating polluted acid include lime neutralization method, high concentration mud method, sulfidation method, lime + iron salt (aluminum salt) method, electrochemical method, biological agent method, membrane method and a combination of several of these methods. The "Lead and Zinc Industrial Pollutant Emission Standard GB 25466-2010" and its amendments stipulate that the total thallium emission concentration limit of wastewater from lead and zinc smelting workshops or production facilities is 0.017 mg / L, and COD Cr The direct emission concentration limit is 60mg / L; the "Copper, Nickel and Cobalt Industrial Pollutant Emission Standard GB 25467-2010" stipulates that the COD Cr The direct emission concentration limit is 60mg / L.

[0003] Except for the reverse osmosis membrane, other methods are usually difficult to separate total thallium and COD Cr However, these methods usually have the disadvantages of high treatment costs, poor effects, large amounts of treatment slag and difficulty in recycling, so there is an urgent need to find an economical and efficient treatment method.

[0004] Sulfur concentrate is a by-product of mineral processing of non-ferrous metal ores and can be used as a raw material for sulfuric acid manufacturing enterprises. In 2020, the national output of sulfur concentrate was 13.25 million tons, about 450 yuan / ton. At present, the research on the use of sulfur concentrate to treat wastewater mainly focuses on the use of sulfur concentrate and strong oxidants to remove organic matter, or to prepare flocculants and adsorbents to remove one or two of the elements such as arsenic, cadmium, chromium, and lead in the wastewater. However, the research on the use of sulfur concentrate to treat multiple pollutants in dirty acid wastewater has not been reported. Based on this, a method for activating sulfur concentrate is proposed, and the activated sulfur concentrate is used to treat smelting dirty acid wastewater. Most of the metals in the wastewater are removed by precipitation of metal sulfides, and thallium is removed by deep precipitation of TlS and Tl(OH)3, and COD Cr The sulfur concentrate is removed by advanced oxidation reaction through activation of sulfur concentrate, and the treated acid wastewater meets the national emission standards. It can be seen that this method has very important promotion and application value. Technical Solutions

[0005] The object of the present invention is to provide a method for treating smelting acid wastewater by using activated sulfur concentrate.

[0006] The object of the present invention is achieved as follows: the method for treating smelting dirty acid wastewater by activating sulfur concentrate includes sulfur concentrate pretreatment, sulfur concentrate activation and dirty acid wastewater treatment steps, specifically comprising:

[0007] A. Pretreatment of sulfur concentrate: drying and grinding the sulfur concentrate. The obtained sulfur concentrate powder is washed twice with pure water and anhydrous ethanol respectively before use. The composition of the sulfur concentrate includes: Fe 42.56-48.95%, S 43.28-49.26%, SiO2 ≤ 3.0%, Zn ≤ 1.12%, and Pb ≤ 0.44%.

[0008] B. Activation of sulfur concentrate: sulfur concentrate powder and Na2S powder are mixed in a mass ratio of 10:1-2, and the mixture is put into a reactor. Pure water is added, and the mass volume ratio of the mixed powder to the added pure water is 400-500 g:1000 mL. The mixture is reacted at 105-115° C., 0.3-0.5 MPa, and 160-200 r / min for 3.5-4.5 hours, and then naturally cooled to room temperature. The reaction solution is filtered, and the filtered activated sulfur concentrate is ventilated, allowed to stand, dried, and ground to obtain activated sulfur concentrate powder for use. The activated sulfur concentrate powder comprises: Fe of 37.28-42.56%, S of 42.64-48.54%, Na of 4.76-8.65%, SiO2≤2.35%, Zn≤0.97%, and Pb≤0.38%.

[0009] C. Treatment of contaminated acid wastewater: add lime milk to the contaminated acid wastewater to adjust the pH value of the wastewater to 2.0-4.0; then add activated sulfur concentrate powder to the contaminated acid wastewater at a rate of 12.0-20.0 g of activated sulfur concentrate powder per 1.0 L of wastewater, supplemented by ultrasonic treatment at a frequency of 25-28 kHz. During this period, the wastewater temperature is maintained at 28-32°C, and the reaction is continuously stirred at a speed of 140-180 r / min for 5-6 hours, and the dissolved oxygen content of the wastewater is maintained at 10.0-15.0 mg / L; then, allow to settle for 30-60 minutes, add lime milk to the supernatant initially obtained after the precipitation, adjust the pH value to 8.0-9.0, continue to allow to settle for 30-60 minutes, and centrifuge the supernatant again to obtain the final treated water.

[0010] Technical principle of the present invention:

[0011] During the oxidation process of sulfur concentrate, dissolved oxygen is adsorbed on the surface of sulfur concentrate and generates H2O2 through a two-electron reduction mechanism, which is then desorbed from the mineral surface into the solution through the Fenton reaction to generate •OH; Fe 2+ Oxidized by O2 to Fe 3+ O2 will be produced at the same time •- , O2 •- Fe 2+Oxidized to Fe 3+ When adding Na2S to activate the sulfur concentrate, more S 2- , polysulfides, etc. The formation of polysulfides will promote the decomposition of H2O2 into •OH, which greatly increases the reaction rate. •OH and O2 in the solution •- Is to remove organic pollutants (ie COD Cr )'s main active ingredient.

[0012] Thallium in acid wastewater + and Tl 3+ There are Tl + Stable existence. Tl in acid wastewater + 、As 3+ 、Hg 2+ 、Cd 2+ , Pb 2+ 、Zn 2+ 、Cu 2+ Most of the generated metal sulfides are precipitated and removed. + In H2O2, •OH and O2 •- Under the combined action of strong oxidation, it is rapidly oxidized into Tl 3+ , with Cd 2+ , Pb 2+ 、Zn 2+ 、Cu 2+ 、Fe 3+ Wait together with OH - The metal hydroxide precipitate formed by the reaction is further removed. - It reacts with lime milk to generate CaF2 for precipitation and removal. During the reaction, activated sulfur concentrate produces trivalent iron oxide and hydroxide particles, which produce a coagulation and co-precipitation effect in the process of heavy metal removal, further improving the efficiency of pollutant removal. Beneficial effects

[0013] Compared with the prior art, the present invention has the following beneficial effects:

[0014] 1. The technical solution of the present invention uses Na2S to activate the pretreated sulfur concentrate powder, which is simple, efficient, safe and economical.

[0015] 2. Activated sulfur concentrate powder is effective in removing thallium and organic pollutants (COD Cr ) at the same time, it can also efficiently and synchronously remove arsenic, mercury, cadmium, lead, zinc, copper and fluoride, and the treated acid wastewater can meet the requirements of "Lead and Zinc Industrial Pollutant Emission Standard GB 25466-2010" and its amendment, and "Copper, Nickel and Cobalt Industrial Pollutant Emission Standard GB 25467-2010".

[0016] 3. The technical solution of the present invention has strong applicability to water quality, a short process flow for treating contaminated acid wastewater, low operating costs and good treatment effect.

[0017] 4. After treating the acid wastewater, the activated sulfur concentrate powder sediment obtained has excellent dehydration performance and can be recycled and reused as sulfur concentrate raw material. Modes for Carrying Out the Invention

[0018] The present invention is further described below, but is not intended to limit the present invention in any way. Any changes or substitutions made based on the teachings of the present invention fall within the scope of protection of the present invention.

[0019] The method for treating smelting acid wastewater with activated sulfur concentrate of the present invention comprises the steps of sulfur concentrate pretreatment, sulfur concentrate activation and acid wastewater treatment, specifically comprising:

[0020] A. Pretreatment of sulfur concentrate: drying and grinding the sulfur concentrate. The obtained sulfur concentrate powder is washed twice with pure water and anhydrous ethanol respectively before use. The composition of the sulfur concentrate includes: Fe 42.56-48.95%, S 43.28-49.26%, SiO2 ≤ 3.0%, Zn ≤ 1.12%, and Pb ≤ 0.44%.

[0021] B. Activation of sulfur concentrate: sulfur concentrate powder and Na2S powder are mixed in a mass ratio of 10:1-2, and the mixture is put into a reactor. Pure water is added, and the mass volume ratio of the mixed powder to the added pure water is 400-500 g:1000 mL. The mixture is reacted at 105-115°C, 0.3-0.5 MPa, and 160-200 r / min for 3.5-4.5 hours, and then naturally cooled to room temperature. The reaction solution is filtered, and the filtered activated sulfur concentrate is ventilated and allowed to stand, then dried and ground to obtain activated sulfur concentrate powder for use. The activated sulfur concentrate powder comprises: Fe of 37.28-42.56%, S of 42.64-48.54%, Na of 4.76-8.65%, SiO2≤2.35%, Zn≤0.97%, and Pb≤0.38%.

[0022] C. Treatment of contaminated acid wastewater: add lime milk to the contaminated acid wastewater to adjust the pH value of the wastewater to 2.0-4.0; then add activated sulfur concentrate powder to the contaminated acid wastewater at a rate of 12.0-20.0 g of activated sulfur concentrate powder per 1.0 L of wastewater, supplemented by ultrasonic treatment at a frequency of 25-28 kHz. During this period, the wastewater temperature is maintained at 28-32°C, and the reaction is continuously stirred at a speed of 140-180 r / min for 5-6 hours, and the dissolved oxygen content of the wastewater is maintained at 10.0-15.0 mg / L; then, allow to settle for 30-60 minutes, add lime milk to the supernatant obtained initially after precipitation, adjust the pH value to 8.0-9.0, continue to allow to settle for 30-60 minutes, and centrifuge the supernatant obtained again to obtain the final treated water.

[0023] In the sulfur concentrate pretreatment process, the sulfur concentrate is a byproduct of the lead-zinc sulfide ore beneficiation process. Drying refers to drying the sulfur concentrate at 100-110°C for 2.5-3.5 hours. Grinding refers to grinding the sulfur concentrate to a particle size that passes a 100-mesh sieve.

[0024] In the sulfur concentrate activation process, the ventilation and standing process refers to allowing the filtered activated sulfur concentrate to stand under ventilation at 30-35°C for 24 hours. The drying process refers to drying the activated sulfur concentrate at 105°C for 3 hours after ventilation and standing. The grinding process refers to grinding the dried activated sulfur concentrate to a particle size that passes through a 200-mesh sieve.

[0025] In the acid wastewater treatment process, the wastewater temperature maintenance refers to maintaining the water temperature by solar heating or by using flue gas waste heat to maintain the water temperature. The concentration indicators of various pollutants in the treated water are: thallium ≤ 0.004mg / L, arsenic ≤ 0.18mg / L, mercury ≤ 0.001mg / L, cadmium ≤ 0.012mg / L, lead ≤ 0.065mg / L, zinc ≤ 0.68mg / L, copper ≤ 0.17mg / L, COD Cr ≤52.87mg / L, fluoride ≤4.56mg / L.

[0026] Example 1

[0027] In all the following examples, pH value was determined by glass electrode method, thallium, arsenic, cadmium, lead, zinc and copper were determined by inductively coupled plasma atomic emission spectrometry, mercury was determined by cold atomic absorption spectrophotometry, chemical oxygen demand (COD Cr ) was determined by the dichromate method, and fluoride ion was determined by the ion selective electrode method.

[0028] The concentration limits for direct discharge of water pollutants from newly-built enterprises in the "Lead and Zinc Industrial Pollutant Emission Standard GB 25466-2010" and its amendment, and the "Copper, Nickel and Cobalt Industrial Pollutant Emission Standard GB 25467-2010" are shown in Table 1.

[0029] Table 1 Concentration limits for direct discharge of water pollutants from newly built enterprises Unit: mg / L (excluding pH value)

[0030] .

[0031] A. Pretreatment of sulfur concentrate: The sulfur concentrate was dried at 105°C for 3 hours, ground into a particle size that could pass a 100-mesh sieve, and the resulting sulfur concentrate powder was washed twice with pure water and then with anhydrous ethanol before use. The sulfur concentrate contains 42.56% Fe, 45.72% S, 2.8% SiO2, 1.12% Zn, and 0.38% Pb.

[0032] B. Activation of Sulfur Concentrate: Mix sulfur concentrate powder and Na2S powder in a mass ratio of 10:1.5, place in a reactor, add pure water, and react at a mass volume ratio of 450 g of mixed powder to 1000 mL of pure water. The mixture is reacted at 110°C, 0.4 MPa, and 180 rpm for 4 hours, then naturally cooled to room temperature. The reaction liquid is filtered, and the filtered activated sulfur concentrate is allowed to stand at 30-32°C with ventilation for 24 hours, then dried at 105°C for 3 hours, and ground to a particle size that passes a 200-mesh sieve to produce activated sulfur concentrate powder for later use. The activated sulfur concentrate powder comprises: 37.28% Fe, 45.05% S, 6.71% Na, 2.24% SiO2, 0.97% Zn, and 0.32% Pb.

[0033] C. Treatment of acid wastewater: Take 10L of lead smelting acid wastewater and place it in a bucket. Let it settle for 24 hours and take the supernatant for testing. The test results are: acidity 78.89g / L, thallium 3.28mg / L, arsenic 28.35mg / L, mercury 0.87mg / L, cadmium 1.53mg / L, lead 6.24mg / L, zinc 57.26mg / L, copper 5.64mg / L, COD Cr 98.65mg / L, fluoride ion 789mg / L.

[0034] Add lime milk to the acid wastewater to adjust the pH value of the wastewater to 2.0; then add activated sulfur concentrate powder to the acid wastewater at a rate of 12.0g / 1.0L of wastewater, supplemented by ultrasonic treatment with an ultrasonic frequency of 25kHz. During this period, the wastewater temperature was kept at 28°C by heating with flue gas waste heat, and the reaction was continuously stirred at a speed of 140r / min for 5h, and the dissolved oxygen content of the wastewater was kept at 10.0mg / L; then the solution was allowed to settle for 30min. Lime milk was added to the supernatant obtained after precipitation, and the pH value was adjusted to 8.0. The supernatant was allowed to settle for 30 minutes. The supernatant obtained again was centrifuged to obtain the final treated water, in which the concentration indicators of various pollutants were: thallium 0.004 mg / L, arsenic 0.18 mg / L, mercury 0.001 mg / L, cadmium 0.012 mg / L, lead 0.056 mg / L, zinc 0.68 mg / L, copper 0.098 mg / L, COD Cr 49.85 mg / L, fluoride 4.56 mg / L, which are lower than the water pollutant emission concentration limits for newly built enterprises in GB 25466-2010 in Table 1.

[0035] Example 2

[0036] A. Pretreatment of sulfur concentrate: Dry the sulfur concentrate at 110°C for 2.5 hours, grind it into a particle size that can pass a 100-mesh sieve, and wash the resulting sulfur concentrate powder twice with pure water and then with anhydrous ethanol for later use. The sulfur concentrate contains 44.32% Fe, 49.26% S, 2.7% SiO2, 1.05% Zn, and 0.44% Pb.

[0037] B. Activation of Sulfur Concentrate: Mix sulfur concentrate powder and Na2S powder in a mass ratio of 10:1, place in a reactor, and add pure water (mass volume ratio of 400 g of mixed powder to 1000 mL of pure water). React at 105°C, 0.3 MPa, and 200 rpm for 4.5 hours, then cool naturally to room temperature. Filter the reaction solution, and let the filtered activated sulfur concentrate stand at 32-34°C with ventilation for 24 hours. Dry at 105°C for 3 hours, and grind to a particle size that passes a 200-mesh sieve to obtain activated sulfur concentrate powder for later use. The activated sulfur concentrate powder comprises: 38.54% Fe, 48.54% S, 4.76% Na, 2.10% SiO2, 0.82% Zn, and 0.38% Pb.

[0038] C. Treatment of dirty acid wastewater: The lead smelting dirty acid wastewater treated was the same as that in Example 1.

[0039] Add lime milk to the acid wastewater to adjust the pH value of the wastewater to 4.0; then add activated sulfur concentrate powder to the acid wastewater at a dosage of 20.0g activated sulfur concentrate powder / 1.0L wastewater, supplemented by ultrasonic treatment, with an ultrasonic frequency of 28kHz, during which the wastewater temperature is maintained at 32°C by solar heating, and the reaction is continuously stirred at a speed of 150r / min for 6h, and the dissolved oxygen content of the wastewater is maintained at 12.0mg / L; then let it settle for 60min, and Lime milk was added to the supernatant obtained after precipitation, and the pH value was adjusted to 9.0. The supernatant was allowed to settle for 60 minutes. The supernatant obtained again was centrifuged to obtain the final treated water, in which the concentration indicators of various pollutants were: thallium 0.002 mg / L, arsenic 0.16 mg / L, mercury 0.0008 mg / L, cadmium 0.011 mg / L, lead 0.052 mg / L, zinc 0.63 mg / L, copper 0.083 mg / L, COD Cr The concentrations of water pollutants in the atmosphere were 42.85 mg / L and 4.23 mg / L, which were lower than the emission concentration limits of water pollutants for newly built enterprises in GB 25466-2010 in Table 1.

[0040] Example 3

[0041] A. Pretreatment of sulfur concentrate: Dry the sulfur concentrate at 100°C for 3.5 hours, grind it into a particle size that can pass a 100-mesh sieve, and wash the resulting sulfur concentrate powder twice with pure water and then with anhydrous ethanol for later use. The sulfur concentrate contains 48.95% Fe, 47.34% S, 2.9% SiO2, 0.85% Zn, and 0.29% Pb.

[0042] B. Activation of Sulfur Concentrate: Mix sulfur concentrate powder and Na2S powder in a mass ratio of 10:2, place in a reactor, add pure water, and react at a mass volume ratio of 500 g of mixed powder to 1000 mL of pure water. The mixture is reacted at 115°C, 0.5 MPa, and 160 rpm for 3.5 hours, then naturally cooled to room temperature. The reaction liquid is filtered, and the filtered activated sulfur concentrate is allowed to stand at 33-35°C with ventilation for 24 hours, then dried at 105°C for 3 hours, and ground to a particle size that passes a 200-mesh sieve to produce activated sulfur concentrate powder for later use. The activated sulfur concentrate powder comprises: 42.56% Fe, 46.65% S, 8.65% Na, 2.28% SiO2, 0.69% Zn, and 0.26% Pb.

[0043] C. Treatment of acid wastewater: Take 10L of copper smelting acid wastewater and place it in a bucket. Let it settle for 24 hours and take the supernatant for testing. The test results are: acidity 86.52g / L, thallium 2.69mg / L, arsenic 17.16mg / L, mercury 0.27mg / L, cadmium 1.87mg / L, lead 9.98mg / L, zinc 30.16mg / L, copper 37.04mg / L, COD Cr 105.86 mg / L, fluoride ion 586 mg / L.

[0044] Add lime milk to the acid wastewater to adjust the pH value of the wastewater to 2.0; then add activated sulfur concentrate powder to the acid wastewater at a rate of 12.0g / 1.0L of wastewater, supplemented by ultrasonic treatment with an ultrasonic frequency of 25kHz. During this period, the wastewater temperature was kept at 28°C by heating with flue gas waste heat, and the reaction was continuously stirred at a speed of 160r / min for 5h, and the dissolved oxygen content of the wastewater was kept at 13.0mg / L; then the solution was allowed to settle for 30min. Lime milk was added to the supernatant obtained after precipitation, and the pH value was adjusted to 8.0. The supernatant was allowed to settle for 30 minutes. The supernatant was centrifuged to obtain the final treated water, in which the concentrations of various pollutants were as follows: thallium 0.003 mg / L, arsenic 0.12 mg / L, mercury 0.0006 mg / L, cadmium 0.010 mg / L, lead 0.065 mg / L, zinc 0.52 mg / L, copper 0.17 mg / L, COD Cr 52.87 mg / L, fluoride 4.17 mg / L, which are lower than the water pollutant emission concentration limits for newly built enterprises in GB 25466-2010 in Table 1.

[0045] Example 4

[0046] A. Pretreatment of sulfur concentrate: Dry the sulfur concentrate at 105°C for 3 hours, grind it into a particle size that can pass a 100-mesh sieve, and wash the resulting sulfur concentrate powder twice with pure water and then with anhydrous ethanol for later use. The sulfur concentrate contains 46.75% Fe, 43.28% S, 3.0% SiO2, 0.98% Zn, and 0.32% Pb.

[0047] B. Activation of Sulfur Concentrate: Mix sulfur concentrate powder and Na2S powder in a mass ratio of 10:1.5, place in a reactor, add pure water, and react at a mass volume ratio of 460 g of mixed powder to 1000 mL of pure water. The mixture is reacted at 112°C, 0.4 MPa, and 170 rpm for 4 hours, then naturally cooled to room temperature. The reaction liquid is filtered, and the filtered activated sulfur concentrate is allowed to stand at 30-33°C with ventilation for 24 hours, then dried at 105°C for 3 hours, and ground to a particle size that passes a 200-mesh sieve to produce activated sulfur concentrate powder for later use. The activated sulfur concentrate powder comprises: 40.65% Fe, 42.64% S, 6.71% Na, 2.35% SiO2, 0.78% Zn, and 0.25% Pb.

[0048] C. Treatment of dirty acid wastewater: The copper smelting dirty acid wastewater treated is the same as that in Example 3.

[0049] Lime milk was added to the acid wastewater to adjust the pH value of the wastewater to 4.0; then activated sulfur concentrate powder was added to the acid wastewater at a dosage of 20.0g / 1.0L of wastewater, and ultrasonic treatment was performed with an ultrasonic frequency of 28kHz. During this period, the wastewater temperature was maintained at 32°C by solar heating, and the reaction was continuously stirred at a speed of 180r / min for 6h, during which the dissolved oxygen content of the wastewater was maintained at 15.0mg / L; then the solution was allowed to settle for 60min. Lime milk was added to the supernatant obtained after precipitation, and the pH value was adjusted to 9.0. The supernatant was allowed to settle for 60 minutes. The supernatant was centrifuged to obtain the final treated water, in which the concentrations of various pollutants were as follows: thallium 0.002 mg / L, arsenic 0.10 mg / L, mercury 0.0005 mg / L, cadmium 0.009 mg / L, lead 0.057 mg / L, zinc 0.48 mg / L, copper 0.15 mg / L, COD Cr 46.75 mg / L, fluoride 3.98 mg / L, which are lower than the water pollutant emission concentration limits for newly built enterprises in GB 25466-2010 in Table 1.

[0050] Example 5

[0051] According to Example 2, 1000.0 g of the activated sulfur concentrate sand powder sediment obtained after treating the acid wastewater was weighed into three beakers, and the mixture was placed in an oven at 105° C. and dried to a constant weight. The mass changes of the three beakers before and after drying were weighed, and the average moisture content of the activated sulfur concentrate sand powder sediment was calculated to be 75%.

[0052] After the activated sulfur concentrate sand powder sediment was filtered through a filter press, 100.0 g of the filter press residue was weighed into three beakers respectively, and the beakers were placed in an oven at 105°C to dry to constant weight. The mass changes of the three beakers before and after drying were weighed, and the average moisture content of the filter press residue was calculated to be 23%.

[0053] This indicates that the activated sulfur concentrate powder sediment has excellent dehydration performance. Elemental analysis by X-ray fluorescence spectroscopy showed that the dry-pressed filter residue contained 41.50% Fe and 44.26% S, and could be recycled as sulfur concentrate raw material.

Claims

1. A method for treating smelting waste acid wastewater by activating sulfur concentrate sand, characterized in that It includes the pretreatment of sulfur concentrate, the activation of sulfur concentrate and the treatment process of waste acid wastewater, specifically including: A. Pretreatment of sulfur concentrate: The sulfur concentrate is dried and ground, and the obtained sulfur concentrate powder is washed twice with pure water and anhydrous ethanol respectively and then reserved for use; the components of the sulfur concentrate include: Fe is 42.56 - 48.95%, S is 43.28 - 49.26%, SiO2 ≤ 3.0%, Zn ≤ 1.12%, Pb ≤ 0.44%; B. Activation of sulfur concentrate: The sulfur concentrate powder and Na2S powder are mixed evenly according to the mass ratio of 10:1 - 2, put into a reaction kettle, pure water is added, and the mass - to - volume ratio of the added mixed powder to the added pure water is 400 - 500g:1000mL. React at 105 - 115°C, 0.3 - 0.5MPa, 160 - 200r / min for 3.5 - 4.5h, then naturally cool to room temperature. Filter the reaction solution, and the filtered activated sulfur concentrate is dried and ground after ventilation and static settlement to obtain activated sulfur concentrate powder for standby; the components of the activated sulfur concentrate powder include: Fe is 37.28 - 42.56%, S is 42.64 - 48.54%, Na is 4.76 - 8.65%, SiO2 ≤ 2.35%, Zn ≤ 0.97%, Pb ≤ 0.38%; C. Treatment of waste acid wastewater: Add lime milk to the waste acid wastewater to adjust the pH value of the wastewater to 2.0 - 4.0; then add activated sulfur concentrate powder to the waste acid wastewater according to the dosage of 12.0 - 20.0g activated sulfur concentrate powder / 1.0L wastewater, supplemented with ultrasonic treatment, the ultrasonic frequency is 25 - 28kHz, keep the wastewater temperature at 28 - 32°C during this period, continuously stir and react at a speed of 140 - 180r / min for 5 - 6h, and keep the dissolved oxygen content of the wastewater at 10.0 - 15.0mg / L; then let it stand and precipitate for 30 - 60min, add lime milk to the supernatant obtained for the first time after precipitation to adjust the pH value to 8.0 - 9.0, continue to let it stand and precipitate for 30 - 60min, and after centrifugally separating the supernatant obtained again, obtain the final treated water.

2. The method for treating smelting waste acid wastewater by activating pyrite cinder according to claim 1, characterized in that In the sulfur concentrate pretreatment process, the sulfur concentrate is a by - product obtained from the sulfide lead - zinc ore beneficiation process.

3. The method for treating smelting waste acid wastewater by activating sulfur concentrate sand according to claim 1, wherein In the sulfur concentrate pretreatment process, the drying means drying the sulfur concentrate at 100 - 110°C for 2.5 - 3.5h.

4. The method for treating smelting waste acid wastewater by activating sulfur concentrate sand according to claim 1, wherein In the sulfur concentrate pretreatment process, the grinding means grinding the sulfur concentrate into a particle size passing through a 100 - mesh sieve.

5. The method for treating smelting waste acid wastewater by activating pyrite cinder according to claim 1, characterized in that In the sulfur concentrate activation process, the ventilation and static settlement means ventilating and statically settling the filtered activated sulfur concentrate at 30 - 35°C for 24h.

6. The method for treating smelting waste acid wastewater by activating sulfur concentrate sand according to claim 1, characterized in that In the sulfur concentrate activation process, the drying means drying the activated sulfur concentrate after ventilation and static settlement at 105°C for 3h.

7. The method for treating smelting waste acid wastewater by activating sulfur concentrate sand according to claim 1, characterized in that In the sulfur concentrate activation process, the grinding means grinding the dried activated sulfur concentrate into a particle size passing through a 200 - mesh sieve.

8. The method for treating smelting waste acid wastewater by activating pyrite cinder according to claim 1, characterized in that In the waste acid wastewater treatment process, the maintaining of the wastewater temperature means maintaining the water temperature by solar heating or by using the waste heat of flue gas.

9. The method for treating smelting waste acid wastewater by activating sulfur concentrate sand according to claim 1, characterized in that In the process of treating waste acid wastewater, the concentration indexes of various pollutants in the treated water are as follows: thallium ≤ 0.004 mg / L, arsenic ≤ 0.18 mg / L, mercury ≤ 0.001 mg / L, cadmium ≤ 0.012 mg / L, lead ≤ 0.065 mg / L, zinc ≤ 0.68 mg / L, copper ≤ 0.17 mg / L, COD Cr ≤ 52.87 mg / L, fluoride ≤ 4.56 mg / L.

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