CN115448372B - Method for solidifying high-arsenic crystal by using composite iron salt through hydrothermal oxygen pressure - Google Patents
Method for solidifying high-arsenic crystal by using composite iron salt through hydrothermal oxygen pressure Download PDFInfo
- Publication number
- CN115448372B CN115448372B CN202211112466.1A CN202211112466A CN115448372B CN 115448372 B CN115448372 B CN 115448372B CN 202211112466 A CN202211112466 A CN 202211112466A CN 115448372 B CN115448372 B CN 115448372B
- Authority
- CN
- China
- Prior art keywords
- arsenic
- scorodite
- solution
- crystal
- crystals
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01G—COMPOUNDS CONTAINING METALS NOT COVERED BY SUBCLASSES C01D OR C01F
- C01G49/00—Compounds of iron
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F11/00—Treatment of sludge; Devices therefor
- C02F11/004—Sludge detoxification
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2002/00—Crystal-structural characteristics
- C01P2002/70—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data
- C01P2002/72—Crystal-structural characteristics defined by measured X-ray, neutron or electron diffraction data by d-values or two theta-values, e.g. as X-ray diagram
-
- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01P—INDEXING SCHEME RELATING TO STRUCTURAL AND PHYSICAL ASPECTS OF SOLID INORGANIC COMPOUNDS
- C01P2004/00—Particle morphology
- C01P2004/01—Particle morphology depicted by an image
- C01P2004/03—Particle morphology depicted by an image obtained by SEM
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2101/00—Nature of the contaminant
- C02F2101/10—Inorganic compounds
- C02F2101/103—Arsenic compounds
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
- C02F2103/16—Nature of the water, waste water, sewage or sludge to be treated from metallurgical processes, i.e. from the production, refining or treatment of metals, e.g. galvanic wastes
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y02P10/00—Technologies related to metal processing
- Y02P10/20—Recycling
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Life Sciences & Earth Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Inorganic Chemistry (AREA)
- Inorganic Compounds Of Heavy Metals (AREA)
- Compounds Of Iron (AREA)
Abstract
The invention discloses a method for solidifying a high-arsenic crystal into scorodite crystals by hydrothermal oxygen pressure, and relates to the field of non-toxicity and harmless arsenic-containing byproducts in nonferrous metal smelting. The invention provides a method for preparing a regular octahedral scorodite crystal by acid dissolution of sodium arsenate crystals produced in lead anode slime resource utilization into a high-arsenic solution, transferring the high-arsenic solution into a hydrothermal kettle, adding solid composite ferric salt, and pressing the high-temperature oxygen into the regular octahedral scorodite crystal. Arsenic concentration in the scorodite crystal toxicity leaching (TCLP) is lower than the specified value of the national standard (GB 5085.3-2007) by 5mg/L, and the scorodite crystal toxicity leaching (TCLP) is suitable for long-term safe storage. The solid composite ferric salt is dissolved in hydrothermal oxygen pressure, so that hydrogen ions released in synthesis are consumed, the acid balance and stabilization of the solution are realized, and the arsenic fixing effect is improved. The invention solves the problems of accumulation of hydrogen ions in scorodite and poor arsenic fixing effect in hydrothermal oxygen synthesis, and achieves the aim of innocuity and innocuity of arsenic in lead anode mud. The invention has the advantages of simple operation, small fluctuation of pH value of the solution, excellent arsenic fixing performance, good stability of scorodite crystals and the like.
Description
Technical Field
The invention relates to the field of non-toxic and harmless arsenic-containing byproducts in nonferrous metal smelting, in particular to a method for solidifying sodium arsenate crystals in lead anode slime resource utilization by adopting solid compound iron salt water under hot oxygen pressure.
Background
Arsenic in electrolytic refining of lead bullionWith elemental As, as 2 O 3 And Cu 0.95 As 4 Is enriched in anode mud, and the content of the anode mud is 1 to 20 percent. In the recycling of lead anode slime, the nontoxic and harmless treatment of arsenic has become an important link of lead clean production. In the alkaline pressure oxidation treatment of lead anode slime, arsenic is oxidized into sodium arsenate with high solubility, and then enters leaching liquid, and sodium arsenate crystals are obtained through evaporation crystallization or cooling crystallization (Yang Tianzu, etc. A method for removing and recovering arsenic from lead anode slime is disclosed in CN101928838B, 2011-12-07). Because the sodium arsenate has small market and water-soluble property, and a large amount of highly toxic sodium arsenate is unreasonably stacked for a long time, serious arsenic pollution is easy to cause, and the sodium arsenate is a non-negligible environmental protection challenge in the clean utilization of lead anode slime.
Scorodite (FeAsO) 4 ·2H 2 O) is highly crystalline ferric arsenate, mainly in the form of biconical, columnar, clustered or grape, etc., having a single crystal particle size of 0.1-0.5 mm, and having a particle size of 3-5 mm, and having a density of 3.10g/cm 3 The color is mainly light green, light yellow, white, etc. The crystal parameters of the regular octahedron scorodite areAnd Z=8, and the space group is Pcab. Standard formation enthalpy of scorodite is-1508.9 kJ/mol, standard entropy is 188.0J.mol -1 ·K -1 Gibbs free energy of-1284.8 kJ/mol, solubility product of only (log K sp Amorphous ferric arsenate (log K) = -26.4 sp One thousandth of = -23.0). Scorodite in natural environment is a efflorescence product of arsenopyrite, and can exist in nature stably, and its stability is mainly represented by FeAsO in acidic medium 4 ·2H 2 O is present to form stable FeAsO under alkaline conditions 4 ·2H 2 O@FeOOH core-shell structure. The scorodite has the advantages of stable crystal structure, high arsenic content (32.5%), small slag content, easy filtration, no toxicity, low storage cost and the like.
Among the methods for synthesizing scorodite, the hydrothermal oxygen pressure method has the advantages of high oxygen utilization rate, coarse scorodite grains, stable crystal structure and convenience for long-term safetyThe storage advantage is received attention from research and development personnel (Yuxiu, et al. Arsenic molten iron thermal coprecipitation preparation of large particle scorodite [ J)]Process engineering report 2018,18 (01): 126-132.). The hydrothermal oxygen pressure method adopts Fe 2+ Introducing oxygen into weak acid As (V) solution, and performing hydrothermal pressurized oxidation to obtain high-crystallinity scorodite crystal, as shown in chemical equation (1). The hydrothermal oxygen pressure method solves the defects of large supersaturation degree, low oxygen utilization rate and poor stability of solid arsenic precipitate in the traditional scorodite synthesis process. But in the process of synthesizing scorodite by hydrothermal oxygen compression, H is taken as a raw material 3 AsO 4 Displaced H + The acid is accumulated in the solution in a large amount, the acidity of the solution is increased, the synthesis of scorodite is inhibited, and the arsenic fixing effect is not ideal. Therefore, in the hydrothermal oxygen pressure method, how to solve the accumulation and stabilization of acid in the solution becomes a key link for improving the arsenic fixing efficiency and synthesizing high-stability scorodite crystals, and also becomes a technical problem that arsenic-containing byproducts are nontoxic and harmless and need to be urgently solved in nonferrous metal smelting.
4Fe 2+ +O 2 +6H 2 O+4H 3 AsO 4 ＝4FeAsO 4 ·2H 2 O+8H + (1)
Disclosure of Invention
In order to solve the problems of the hazard of high-arsenic crystals in the recycling of lead anode slime and the poor acid accumulation and arsenic fixing effect in the scorodite crystals synthesized by hydrothermal oxygen synthesis. The first aim of the invention is to convert sodium arsenate crystals into stable scorodite crystals in lead anode slime resource utilization by adopting a hydrothermal oxygen pressure method, thereby realizing non-toxic and harmless arsenic-containing byproducts in nonferrous metal smelting. The method is very suitable for Gao Shen solution, and the synthesized scorodite has complete crystal development, high stability and convenient long-term safe storage.
The second object of the invention is to provide a solid composite ferric salt containing Fe (II) and Fe (III) simultaneously for hydrothermally and aerobically solidifying high-arsenic crystals into scorodite, and neutralizing acid generated in the synthesis process to realize acid balance and stabilization of the solution. The scorodite crystal synthesized by the composite ferric salt has the advantages of coarse particles, good crystallinity, excellent arsenic fixing performance and small pH change at the reaction end point.
In order to achieve the above purpose, the present invention provides the following technical solutions: adding sodium arsenate crystal produced in the lead anode slime utilization process into distilled water, then dripping a proper amount of sulfuric acid to regulate the initial pH value of the solution to be weak acidity, and continuously stirring to completely dissolve the sodium arsenate crystal into H n AsO 4 (3-n)- (n=0 to 3). Transferring the solution into a hydrothermal kettle, adding solid composite ferric salt, introducing oxygen at high temperature, maintaining a certain oxygen pressure, uniformly stirring to co-precipitate and crystallize arsenic and iron, and performing decompression, cooling, filtering and washing after the reaction is completed to obtain the regular octahedron scorodite crystal. The essence of the invention is to realize the dissolution of sodium arsenate crystals by utilizing the principle that sodium arsenate is easily converted into arsenic acid with higher solubility in an acid solution. And then the principle that hydrogen ions generated in the scorodite synthesis process are consumed by the oxidation and dissolution of the solid composite ferric salt is utilized to realize the acid balance and stabilization of the reaction in the intermediate solution.
In order to achieve the above purpose, the present invention provides the following technical solutions:
(1) Acidic dissolution
Adding sodium arsenate crystal into distilled water, dripping a proper amount of sulfuric acid, stirring and dissolving to prepare high-arsenic solution. Adding 100g of sodium arsenate crystal into distilled water according to the liquid-solid ratio of (17-2): 1, uniformly stirring and slurrying, dropwise adding sulfuric acid according to the mass ratio of sulfuric acid to sodium arsenate crystal of (2.5-4.5) until the solution pH=1-4, and continuously stirring for 1-3 hours until the sodium arsenate crystal is completely dissolved, thereby obtaining the acidic high-arsenic solution containing 10-65 g/L of arsenic. The chemical reactions that may occur in this process are as follows:
2Na 3 AsO 4 ·12H 2 O+3H 2 SO 4 ＝3Na 2 SO 4 +2H 3 AsO 4 +24H 2 O (2)
(2) Scorodite crystal synthesis
The scorodite crystal is prepared by adding solid composite ferric salt into high arsenic solutionContinuous oxygen-supplying hydrothermal oxygen synthesis, and solid composite ferric salt for consuming H generated in synthesis + The acid balance of the solution is stabilized. Adding the Gao Shen solution into a hydrothermal kettle, and adding solid composite ferric salt according to the iron-arsenic molar ratio of (1.05-4.5) 1, wherein the iron ratio n of two valence states in the solid composite ferric salt (Fe(II)) :n (Fe(III)) (1-4) = (9-6), then sealing the reaction kettle, exhausting, closing the air inlet valve and the air outlet valve, regulating the rotating speed to 200-600 r/min, heating to 110-180 ℃, opening the oxygen valve, introducing oxygen into the kettle, keeping the oxygen partial pressure to be 0.10-0.60 MPa, and continuously preserving the heat for 3-12 hours to enable the arsenic and the iron to co-precipitate and crystallize. After the reaction is finished, the oxygen valve is closed, the exhaust valve is gradually opened to release pressure after the temperature is reduced and cooled to the room temperature, the slurry in the reaction kettle is taken out, and the liquid and solid separation is realized by vacuum suction filtration. Washing and filtering the precipitate, and drying at 60-80 ℃ for 4-8 hours to obtain scorodite crystals. The chemical reaction of the solid composite ferric salt in the synthesis of scorodite crystals by hydrothermal oxygen compression is shown as formulas (4) to (13), wherein formulas (4) to (9) consume hydrogen ions and generate Fe for the oxidation and dissolution of the solid composite ferric salt 3+ The reaction of (2) is carried out by the following formulae (10) to (12) being Fe 3+ And H n AsO 4 (3-n)- The coprecipitation is a reaction of scorodite crystals and releasing hydrogen ions, the proportion of two valence ferric salts in the solid composite ferric salt is regulated, the hydrogen ion balance in the whole synthesis process is realized, and the aims of stabilizing the pH value of the solution and improving the arsenic fixing rate are achieved.
Fe 2 O 3 +6H + ＝Fe 3+ +3H 2 O (4)
Fe(OH) 3 +3H + ＝Fe 3+ +3H 2 O (5)
4Fe 3 O 4 +36H + +O 2 ＝12Fe 3+ +18H 2 O (6)
4Fe(OH) 2 +O 2 +12H + ＝4Fe 3+ +6H 2 O (7)
4FeO+O 2 +12H + ＝4Fe 3+ +6H 2 O (8)
4Fe 2+ +O 2 +4H + ＝4Fe 3+ +2H 2 O (9)
Fe 3+ +H 3 AsO 4 +2H 2 O＝FeAsO 4 ·2H 2 O+3H + (10)
Fe 3+ +H 2 AsO 4 - +2H 2 O＝FeAsO 4 ·2H 2 O+2H + (11)
Fe 3+ +HAsO 4 2- +2H 2 O＝FeAsO 4 ·2H 2 O+H + (12)
Fe 3+ +AsO 4 3- +2H 2 O＝FeAsO 4 ·2H 2 O (13)
The high arsenic crystal used in the invention is sodium arsenate crystal generated in lead anode slime resource utilization, and the phase is Na 3 AsO 4 ·xH 2 O (x=10, 12), wherein the main chemical components (w.t%) are Na 15-24, A15-25, sb 0.15-0.30, the rest impurities are Ca, cd, pb less than or equal to 0.10 and the crystallization water is 45-55.
The solid composite ferric salt used in the invention is ferric iron and ferrous iron which are formed according to different proportions, wherein the ferric iron is Fe 2 O 3 、Fe(OH) 3 FeOOH, rust (Fe) 2 O 3 ·nH 2 O)、Fe 2 (CO 3 ) 3 And ferrihydrite, the ferrous iron mainly comprises FeO and Fe (OH) 2 、FeSO 4 、FeSO 4 ·7H 2 O、FeCl 2 ·4H 2 O Fe(NH 4 ) 2 ·(SO 4 ) 2 ·6H 2 O, etc., fe containing both ferrous iron and ferric iron 3 O 4 。
The sulfuric acid used in the invention is an analytically pure reagent, the content of which is more than 98%, and the oxygen is industrial grade gas, the content of which is more than 99.5%.
Toxicity leaching experiment (TCLP), according to the operation standard of solid waste leaching toxicity leaching method-nitric acid sulfuric acid method HJ/T299-2007, adding the synthesized flaky scorodite crystal material into aqueous solution of nitric acid sulfuric acid with pH=3.15-3.25 according to the liquid-solid ratio of 10:1, horizontally oscillating for 16-20 hours, standing, filtering supernatant with a filter membrane of 0.8 mu m, and measuring arsenic concentration of the toxic leaching liquid by ICP-AES. According to the requirements of hazardous waste identification standard-leaching toxicity identification (GB 5085.3-2007), when the arsenic concentration in the determined toxic leaching solution is less than 5mg/L, the synthesized scorodite crystal can be considered as a nontoxic harmless arsenic-fixing material, and can be safely stored.
Compared with the traditional method for solidifying arsenic into scorodite from arsenic-containing solution by hydrothermal oxygen pressure, the invention has the following advantages: (1) After the sodium arsenate crystals produced by the lead anode slime resource utilization are subjected to hydrothermal oxygen pressure solidification to form scorodite crystals, the arsenic in the lead anode slime is nontoxic and harmless; (2) The oxidation and dissolution of the solid composite ferric salt consume hydrogen ions generated in the synthesis of scorodite, realize acid balance in the solution and are beneficial to improving arsenic fixing efficiency; (4) The synthesized scorodite is a regular octahedral crystal form with coarse particles, the crystal grains are complete in development, the arsenic concentration in the toxic leaching solution is far less than 5mg/L, the crystal structure is stable, and the scorodite is suitable for long-term safe storage; (5) The hydrothermal oxygen pressure method is suitable for high-arsenic solution with arsenic concentration of 10-65 g/L, the arsenic fixation rate is more than 99.5%, the arsenic concentration in the reacted solution is lower than 50mg/L, and the treatment burden on arsenic-containing wastewater is reduced.
Drawings
FIG. 1 is a process flow diagram of the present invention;
FIG. 2 is an XRD pattern of a synthetic scorodite crystal according to the invention;
FIG. 3 is an SEM image of a synthetic scorodite crystal of the present invention.
Detailed description of the preferred embodiments
For the purpose of making the objects, technical solutions and advantages of the embodiments of the present invention more apparent, the technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is apparent that the described embodiments are some embodiments of the present invention, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
Example 1:
100g of sodium arsenate crystal is weighed and added into 1650mL of distilled water according to the liquid-solid ratio of 16.5:1, and the mixture is evenly stirred and pulped, and sulfuric acid and sodium arsenate are preparedSulfuric acid is added dropwise to the solution with the mass ratio of 1:2.5 until the initial pH=3.0, and stirring is continued for 1 hour until the crystals are completely dissolved, so that the high-arsenic solution with arsenic content of 10g/L is obtained. Adding the high-arsenic solution into a hydrothermal kettle, and adding solid composite ferric salt according to the molar ratio of iron to arsenic of 1.4:1, wherein the molar ratio of two valence-state irons in the solid composite ferric salt is n (Fe(II)) :n (Fe(III)) And (2) sealing the reaction kettle, exhausting the air, closing an air inlet valve and an air outlet valve, regulating the rotating speed to 300 revolutions per minute, heating to 120 ℃, opening an oxygen valve, introducing oxygen into the kettle, keeping the oxygen partial pressure to be 0.20MPa, and continuously preserving the temperature for 5 hours to enable arsenic and iron to co-precipitate into scorodite crystals. After the reaction is finished, the oxygen valve is closed, the exhaust valve is gradually opened to release pressure after the temperature is reduced and cooled to the room temperature, the slurry in the reaction kettle is taken out, and the liquid and solid separation is realized by vacuum suction filtration. And washing and filtering the precipitate, and drying at 60 ℃ for 5 hours to obtain scorodite crystals. The arsenic fixing rate in the synthesis is 99.6%, the pH value of the solution after arsenic fixing is 2.95, the solution is close to the initial pH value of the solution, and the acid in the solution is basically balanced, so that the acid stabilization regulation and control target is realized.
Example 2:
100g of sodium arsenate crystal is weighed and added into 375mL of distilled water according to the liquid-solid ratio of 3.75:1, uniformly stirred and pulped, sulfuric acid is added dropwise according to the mass ratio of sulfuric acid to sodium arsenate crystal of 1:3.5 until the pH=2.0 of the initial solution, and then the stirring is continued for 1.5 hours until the crystal is completely dissolved, thus obtaining the acid high-arsenic solution containing 40g/L of arsenic. Adding the high-arsenic solution into a hydrothermal kettle, and adding solid composite ferric salt according to the iron-arsenic molar ratio of 1.2:1, wherein the iron molar ratio of two valence states in the solid composite ferric salt is n (Fe(II)) :n (Fe(III)) After the reaction kettle is sealed and exhausted, an air inlet valve and an air outlet valve are closed, the rotating speed is adjusted to 400 revolutions per minute, the temperature is raised to 130 ℃, an oxygen valve is opened, oxygen is introduced into the kettle, the oxygen partial pressure is kept to be 0.40MPa, and the temperature is kept for 7 hours continuously, so that arsenic and iron are coprecipitated into scorodite crystals. After the reaction is finished, the oxygen valve is closed, the exhaust valve is gradually opened to release pressure after the temperature is reduced and cooled to the room temperature, the slurry in the reaction kettle is taken out, and the liquid-solid separation is realized by vacuum suction filtration. And washing and filtering the precipitate, and drying at 80 ℃ for 8 hours to obtain scorodite crystals. The arsenic fixing rate in the synthesis is99.8 percent, the pH value of the solution after arsenic fixation is 1.98, which is close to the initial pH value of the solution, and the acid in the solution is basically balanced, thus realizing the aim of regulating and controlling the acid stabilization.
Example 3:
100g of sodium arsenate crystal is weighed and added into 240mL of distilled water according to the liquid-solid ratio of 2.4:1, evenly stirred and pulped, sulfuric acid is added dropwise according to the mass ratio of sulfuric acid to sodium arsenate crystal of 1:4 until the initial pH=1.0 of the solution, and stirring is continued for 2 hours until the crystal is completely dissolved, thus obtaining 60g/L acidic high-arsenic solution containing arsenic. Adding the high-arsenic solution into a hydrothermal kettle, adding solid composite ferric salt according to the iron-arsenic molar ratio of 2:1, wherein the iron molar ratio of two valence states in the solid composite ferric salt is n (Fe(II)) :n (Fe(III)) After the reaction kettle is sealed and exhausted, an air inlet valve and an air outlet valve are closed, the rotating speed is adjusted to 600 revolutions per minute, the temperature is raised to 160 ℃, an oxygen valve is opened, oxygen is introduced into the kettle, the oxygen partial pressure is kept to be 0.50MPa, and the continuous heat preservation is carried out for 10 hours, so that arsenic and iron are coprecipitated into scorodite crystals. After the reaction is finished, the oxygen valve is closed, the exhaust valve is gradually opened to release pressure after the temperature is reduced and cooled to the room temperature, the slurry in the reaction kettle is taken out, and the liquid and solid separation is realized by vacuum suction filtration. Washing and filtering the precipitate, and drying at 80 ℃ for 8 hours to obtain scorodite crystals. The arsenic fixing rate in the synthesis is 99.9%, the pH value of the solution after arsenic fixing is 1.05, the solution is close to the initial pH value of the solution, and the acid in the solution is basically balanced, so that the acid stabilization regulation and control target is realized.
The scorodite crystal materials synthesized by the method are subjected to toxicity leaching experiments according to the operation standard of solid waste leaching toxicity leaching method-nitric acid sulfuric acid method HJ/T299-2007, and the toxicity leaching liquid is determined by ICP-AES, has arsenic concentration lower than 5mg/L, is a nontoxic harmless arsenic-fixing material, and is suitable for long-term safe storage.
FIG. 1 is a technical flow chart of the invention, which consists of two key processes of acid dissolution of high-arsenic crystals and synthesis of scorodite by hydrothermal oxygen compression. The high-arsenic crystal is dissolved into an acidic high-arsenic solution in acidity, the solution is converted into stable scorodite crystals by hydrothermal oxygen pressure, and the solid composite ferric salt is mainly used for neutralizing hydrogen ions generated in synthesis, so that the aims of solution acid balance and high-efficiency arsenic fixation in a synthesis system are fulfilled. The two procedures are closely connected to form a safe, nontoxic and harmless technology for recycling the high-arsenic crystals in the lead anode slime.
FIG. 2 shows that the scorodite crystals synthesized by hydrothermal oxygen synthesis are FeAsO with sharp diffraction peaks 4 ·2H 2 The O-phase, at 2θ=15.78 °,19.82 °,28.04 °,29.16 °, and 35.82 °, corresponds to (1 1 1), (2 0), (2 1 2), (1 3 1), and (3 2 0) crystal planes, respectively, indicating that the synthesized scorodite crystals are well crystalline. FIG. 3 shows that the synthesized scorodite has a regular octahedral crystal structure with a particle size of 10-15 μm, the crystal is uniformly distributed, the particles are coarse, the scorodite has a complete crystal development and a complete structure in hydrothermal oxygen pressure, and the scorodite has good stability.
In conclusion, the solid composite ferric salt provided by the invention can effectively neutralize hydrogen ions released in the process of synthesizing scorodite by hydrothermal oxygen, so that acid balance and stability in the solution are realized. Is suitable for the non-toxic and harmless treatment of high-arsenic crystals in lead anode slime resource utilization, and achieves the safety treatment and environmental protection of arsenic in lead anode slime.
Claims (3)
1. A method for hydrothermally and oxygen pressure solidification of high-arsenic crystals by composite iron salt, which is characterized by comprising the following steps:
(1) Acid dissolution:
adding sulfuric acid into distilled water to regulate the pH value of the solution to dissolve the high-arsenic crystal, thereby obtaining high-arsenic solution;
adding 100g of high-arsenic crystal into distilled water according to the liquid-solid ratio of (17-2), uniformly stirring and slurrying, and dripping sulfuric acid to the initial pH value of the solution=1-4 according to the mass ratio of sulfuric acid to the high-arsenic crystal of (2.5-4.5), and reacting for 1-3 hours until the high-arsenic crystal is completely dissolved to obtain high-arsenic solution containing 10-65 g/L of arsenic;
(2) Synthesis of scorodite crystals:
adding solid composite ferric salt into the high-arsenic solution, continuously introducing oxygen, hydrothermal and oxygen to synthesize scorodite crystals, and consuming H released in synthesis by oxidation and dissolution of the solid composite ferric salt + Acid balance and stabilization in the solution are realized;
firstly, adding high arsenic solution into a hydrothermal kettle according to the mole ratio of iron to arsenic of (1.05-4.5): 1Adding solid composite ferric salt, wherein the molar ratio n of two valence state iron in the solid composite ferric salt (Fe(II)) :n (Fe(III)) ＝(1～4):(9～6)；
Secondly, sealing the reaction kettle, regulating the rotating speed to 200-600 rpm, heating to 100-180 ℃, introducing oxygen into the kettle, keeping the oxygen partial pressure to be 0.10-0.60 MPa, and continuously preserving the heat for 3-12 hours;
finally, after the reaction is finished, closing an oxygen valve, cooling, decompressing, taking out slurry in the reaction kettle, performing liquid-solid separation by vacuum suction filtration, washing and filtering sediment, and drying at 60-80 ℃ for 4-8 hours to obtain scorodite crystals;
the solid composite ferric salt is composed of ferric iron and ferrous iron according to different proportions, wherein the ferric iron is as follows: fe (Fe) 2 O 3 、Fe(OH) 3 FeOOH, rust (Fe) 2 O 3 ·nH 2 O)、Fe 2 (CO 3 ) 3 And ferrihydrite; the ferrous iron is as follows: feO, fe (OH) 2 、FeSO 4 、FeSO 4 ·7H 2 O、FeCl 2 ·4H 2 O、Fe(NH 4 ) 2 ·(SO 4 ) 2 ·6H 2 O, and Fe containing both ferric iron and ferrous iron 3 O 4 。
2. The method for solidifying high-arsenic crystals by hot water oxygen pressure of composite iron salt according to claim 1, wherein the high-arsenic crystals are sodium arsenate crystals produced in lead anode slime recycling, and the phases are Na 3 AsO 4 ·10H 2 O and/or Na 3 AsO 4 ·12H 2 The main chemical components of the O are 15-24% of Na, 15-25% of As, 0.15-0.30% of Sb, and the balance of impurities Ca, cd and Pb which are less than 0.10% and the crystallization water is 45-55%.
3. The method for solidifying high-arsenic crystals by using the composite iron salt hydrothermal oxygen pressure according to claim 1, which is characterized in that the scorodite crystals formed by the hydrothermal oxygen pressure have single phase and have a regular octahedral crystal form with a microcosmic appearance of 10-15 μm, and the method is good in stability, is a nontoxic harmless arsenic-solidifying material, and is suitable for long-term safe storage.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211112466.1A CN115448372B (en) | 2022-09-14 | 2022-09-14 | Method for solidifying high-arsenic crystal by using composite iron salt through hydrothermal oxygen pressure |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202211112466.1A CN115448372B (en) | 2022-09-14 | 2022-09-14 | Method for solidifying high-arsenic crystal by using composite iron salt through hydrothermal oxygen pressure |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN115448372A CN115448372A (en) | 2022-12-09 |
| CN115448372B true CN115448372B (en) | 2023-09-22 |
Family
ID=84303314
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202211112466.1A Active CN115448372B (en) | 2022-09-14 | 2022-09-14 | Method for solidifying high-arsenic crystal by using composite iron salt through hydrothermal oxygen pressure |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN115448372B (en) |
Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7314604B1 (en) * | 1999-09-30 | 2008-01-01 | Billiton Intellectual Property, B.V. | Stable ferric arsenate precipitation from acid copper solutions whilst minimising copper losses |
| CN102674526A (en) * | 2012-05-14 | 2012-09-19 | 中南大学 | Method for precipitating and stabilizing As from As-containing solution |
| WO2013173914A1 (en) * | 2012-05-25 | 2013-11-28 | The University Of British Columbia | Arsenic recovery from copper-arsenic sulphides |
| CN103964601A (en) * | 2013-02-06 | 2014-08-06 | 中国科学院沈阳应用生态研究所 | Method for treating arsenic-containing industrial wastewater |
| JP2015003852A (en) * | 2013-05-21 | 2015-01-08 | 国立大学法人東北大学 | Method of producing crystalline iron arsenate from solution containing pentavalent arsenic |
| CN107512739A (en) * | 2017-08-15 | 2017-12-26 | 昆明理工大学 | A kind of method of the heavy arsenic of the complicated arsenic containing solution normal pressure of acidity |
| CN107794372A (en) * | 2017-10-25 | 2018-03-13 | 湖南水口山有色金属集团有限公司 | A kind of dearsenification selective from lead anode slurry and the method for zero emission of wastewater treatment |
| CN111039327A (en) * | 2019-12-31 | 2020-04-21 | 福州大学 | Method for converting arsenic slag into scorodite in one step |
| CN111170510A (en) * | 2020-01-20 | 2020-05-19 | 宁波弗镁瑞环保科技有限公司 | Method for treating arsenic-containing wastewater and solidifying arsenic |
| CN114561558A (en) * | 2022-02-23 | 2022-05-31 | 中南大学 | Method for recovering antimony and solid arsenic from arsenic-containing crystal |
-
2022
- 2022-09-14 CN CN202211112466.1A patent/CN115448372B/en active Active
Patent Citations (10)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7314604B1 (en) * | 1999-09-30 | 2008-01-01 | Billiton Intellectual Property, B.V. | Stable ferric arsenate precipitation from acid copper solutions whilst minimising copper losses |
| CN102674526A (en) * | 2012-05-14 | 2012-09-19 | 中南大学 | Method for precipitating and stabilizing As from As-containing solution |
| WO2013173914A1 (en) * | 2012-05-25 | 2013-11-28 | The University Of British Columbia | Arsenic recovery from copper-arsenic sulphides |
| CN103964601A (en) * | 2013-02-06 | 2014-08-06 | 中国科学院沈阳应用生态研究所 | Method for treating arsenic-containing industrial wastewater |
| JP2015003852A (en) * | 2013-05-21 | 2015-01-08 | 国立大学法人東北大学 | Method of producing crystalline iron arsenate from solution containing pentavalent arsenic |
| CN107512739A (en) * | 2017-08-15 | 2017-12-26 | 昆明理工大学 | A kind of method of the heavy arsenic of the complicated arsenic containing solution normal pressure of acidity |
| CN107794372A (en) * | 2017-10-25 | 2018-03-13 | 湖南水口山有色金属集团有限公司 | A kind of dearsenification selective from lead anode slurry and the method for zero emission of wastewater treatment |
| CN111039327A (en) * | 2019-12-31 | 2020-04-21 | 福州大学 | Method for converting arsenic slag into scorodite in one step |
| CN111170510A (en) * | 2020-01-20 | 2020-05-19 | 宁波弗镁瑞环保科技有限公司 | Method for treating arsenic-containing wastewater and solidifying arsenic |
| CN114561558A (en) * | 2022-02-23 | 2022-05-31 | 中南大学 | Method for recovering antimony and solid arsenic from arsenic-containing crystal |
Non-Patent Citations (4)
| Title |
|---|
| A novel process of immobilizing sodium arsenate crystals as scorodite using Fe(OH)3 as an iron source;Zanlang Tang等;《Process Safety and Environmental Protection 》;第550-564页 * |
| 含砷铁溶液水热臭葱石沉砷研究;余自秀;李存兄;魏昶;杨晨年;邓志敢;李兴彬;樊刚;;昆明理工大学学报(自然科学版)(01);第1-8页 * |
| 磁性Fe3O4处置铜冶炼污酸技术研究;李勋;《中国优秀硕士学位论文全文数据库 工程科技Ⅰ辑》;第23-24、28、41-45页 * |
| 铅阳极泥臭葱石脱砷工艺研究;卢铭;《中国优秀硕士学位论文全文数据库 工程科技Ⅰ辑》;第16-17页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN115448372A (en) | 2022-12-09 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Ooi et al. | Mechanism of lithium (1+) insertion in spinel-type manganese oxide. Redox and ion-exchange reactions | |
| Chitrakar et al. | Synthesis of spinel-type lithium antimony manganese oxides and their Li+ extraction/ion insertion reactions | |
| CN102329964B (en) | Method for separating and recovering vanadium and chromium from vanadium-chromium reduced waste residue | |
| CN111170510B (en) | Method for treating arsenic-containing wastewater and solidifying arsenic | |
| CN109500059B (en) | Transformation and microcapsule curing stabilization method for arsenic sulfide slag | |
| CN111115681B (en) | Inert atmosphere one-step method for preparing high-purity phase Ti4O7Method for preparing nano material | |
| CN114684801B (en) | Method for preparing high-purity ferric phosphate by using pyrite cinder | |
| WO2014047764A1 (en) | Method for producing high-purity nanometer zinc oxide from steel plant smoke and dust by ammonia decarburization | |
| WO2022260542A1 (en) | Process and system for lithium extraction | |
| CN114561558B (en) | Method for recycling antimony and fixing arsenic from arsenic-containing crystal | |
| CN106868320A (en) | A kind of preparation method of the solid arsenic mineral of high stability | |
| CN110407250B (en) | Method for stabilizing treatment and recycling sulfur by converting arsenic-containing waste residues into arsenite | |
| CN115448372B (en) | Method for solidifying high-arsenic crystal by using composite iron salt through hydrothermal oxygen pressure | |
| CN108063295B (en) | Method for extracting lithium from slag generated by pyrogenic recovery of lithium battery | |
| WO2020138137A1 (en) | Method for purifying vanadium oxide | |
| CN115367722B (en) | Method for preparing ferric phosphate from ferrophosphorus ore | |
| AU2016318839A1 (en) | Recycling process of wastewater containing ammonium ion and preparation method of metal oxide | |
| US20240010514A1 (en) | Nanomaterial Composites Useful for the Extraction and Recovery of Lithium from Aqueous Solutions | |
| CN115304105B (en) | Method for thermally curing arsenic-rich crystals | |
| WO2012058801A1 (en) | A hydrothermal oxidation method for production of alkali metal dichromate from carbon ferrochrome | |
| JP4552324B2 (en) | Method for producing cobalt oxide particles by neutralization method | |
| CN102765762B (en) | Method for preparing nickelous carbonate by utilization of waste ammonia decomposition catalyst | |
| CN111170596A (en) | Treatment method of electroplating sludge containing Cr, Fe and Ca | |
| CN106823235A (en) | A kind of method that regulation and control growth method prepares the solid arsenic mineral of high stability | |
| CN105110380A (en) | Method utilizing calcium-magnesium-contained ferrous chloride solution for preparing pigment-grade Fe2O3 |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |