CN112782250B - Preparation method of sulfide ore working electrode, working electrode and research method - Google Patents
Preparation method of sulfide ore working electrode, working electrode and research method Download PDFInfo
- Publication number
- CN112782250B CN112782250B CN202011600450.6A CN202011600450A CN112782250B CN 112782250 B CN112782250 B CN 112782250B CN 202011600450 A CN202011600450 A CN 202011600450A CN 112782250 B CN112782250 B CN 112782250B
- Authority
- CN
- China
- Prior art keywords
- working electrode
- sulfide ore
- electrode
- powder
- chalcopyrite
- 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
Images
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/28—Electrolytic cell components
- G01N27/30—Electrodes, e.g. test electrodes; Half-cells
Landscapes
- Chemical & Material Sciences (AREA)
- Life Sciences & Earth Sciences (AREA)
- Health & Medical Sciences (AREA)
- Physics & Mathematics (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Electrochemistry (AREA)
- Molecular Biology (AREA)
- Analytical Chemistry (AREA)
- Biochemistry (AREA)
- General Health & Medical Sciences (AREA)
- General Physics & Mathematics (AREA)
- Immunology (AREA)
- Pathology (AREA)
- Testing Resistance To Weather, Investigating Materials By Mechanical Methods (AREA)
Abstract
The invention belongs to the technical field of electrochemistry, and particularly relates to a preparation method of a sulfide ore working electrode for measuring an electrochemical signal under a sulfide ore pressure leaching process condition, the sulfide ore working electrode and a method for researching the sulfide ore pressure leaching process by applying the working electrode. The problems that a device and a method for measuring dynamic high-temperature high-pressure electrochemical signals are lack and a natural block electrode is lack of representativeness in the prior art are solved. The sulfide ore working electrode is formed by adding a binder (PVDF) into carbon powder and mineral powder which are mixed according to a certain proportion and pressing. Testing the chalcopyrite leaching electrochemical mechanism at different temperatures by using open-circuit potential testing, polarization curve testing and alternating-current impedance spectrum testing technologies; the number of sub-processes in the leaching process can be distinguished by means of an alternating current impedance technology, the kinetic parameters of each sub-process are obtained by methods such as equivalent circuit simulation and the like, and the forming and growing mechanism of the chalcopyrite surface passivation film is determined.
Description
Technical Field
The invention belongs to the technical field of electrochemistry, and particularly relates to a preparation method of a sulfide ore working electrode for measuring an electrochemical signal under a sulfide ore pressure leaching process condition, the sulfide ore working electrode and a method for researching the sulfide ore pressure leaching process by applying the working electrode.
Background
Chalcopyrite and other sulphide ores have stable structures and are difficult to leach under the conditions of normal temperature and normal pressure. The pressure leaching is used as a reinforced leaching means, has the advantages of high efficiency, no pollution, short flow and the like, and has very wide application prospect.
Taking chalcopyrite as an example, as can be seen from a potential-pH diagram calculated by theory, the temperature rise, the stable region of the chalcopyrite and the stable region of the sulfur shrink, so that the overlapping region of the chalcopyrite and the stable region of the sulfur becomes small, and with the support of the theory, the pressure leaching kinetic study on the chalcopyrite leads to the following conclusion: increasing temperature and pressure, chalcopyriteCopper in the medium is Cu 2+ Into a leaching solution; iron in small amount of Fe 2+ Or Fe 3+ The ore enters a leaching solution in a form, and a large amount of hematite and a small amount of pyrite exist in leaching slag; most of sulfur enters the leaching solution in the form of sulfate radical, and the passivation phenomenon of sulfur coating can be avoided by high-temperature leaching.
Although the leaching effect of the chalcopyrite can be improved by pressure leaching, the leaching slag still contains the chalcopyrite which is not completely reacted, and the leaching mechanism is not clear. In the oxidation leaching process of the chalcopyrite, along with the transfer process of electrons, the leaching mechanism of the chalcopyrite can be deeply characterized in real time by virtue of an electrochemical testing technology. The electrochemical testing method can effectively avoid the defects of the traditional physicochemical testing methods (methods such as XPS and AES), particularly can effectively avoid the change of the real state of a sample in the preparation, storage and detection processes when the electrochemical mechanism of the chalcopyrite pressure leaching is researched, and reduce the accidental errors in the research of the composition and thickness of a passivation film. At present, most of chalcopyrite electrochemical mechanism researches are based on a steady-state or quasi-steady-state direct current electrochemical testing technology, are difficult to measure sub-processes or steps of an overall process, cannot determine a time constant in a reaction process at all, and cannot capture the characteristics of step-by-step kinetics. And under the high-temperature and high-pressure condition of pressure leaching, the structure of the electrode has high requirements, and the measurement and output of electrochemical signals become very difficult.
In general, a natural block electrode is used for high-temperature high-pressure electrochemical testing of chalcopyrite and other sulfide ores, however, the natural block electrode has the disadvantages of difficult search and no representativeness, and electrochemical behaviors in the leaching process under the actual conditions cannot be obtained completely and truly by measuring electrochemical signals (such as a polarization curve, an alternating-current impedance spectrum and the like) of the block electrode under the high-temperature high-pressure condition of pressure leaching. Therefore, the lack of devices and methods that can measure dynamic high-temperature high-pressure electrochemical signals has hindered the intensive research on the dynamic leaching behavior and mechanism in the high-temperature high-pressure leaching process.
Disclosure of Invention
Aiming at the problems and overcoming the defects of an electrochemical testing technology under a pressure leaching process of sulphide ores such as chalcopyrite and the like, the invention provides a method for carrying out an electrochemical test (especially a dynamic electrochemical test) under a high-temperature high-pressure process condition of pressure leaching by using a working electrode prepared from sulphide ore powder to replace a natural block electrode. The obtained electrochemical signal (especially dynamic electrochemical signal) of the sulfide ore under the pressure leaching condition accords with the real situation of the pressure leaching of the sulfide ore, and can be better used for research and analysis of the pressure leaching process of the sulfide ore.
The working electrode for measuring electrochemical signals in the sulfide ore pressure leaching process is prepared by the following method:
(1) and (3) pretreating, crushing and grinding the sulfide ores to prepare sulfide ore powder.
(2) And mixing carbon powder and the sulfide ore powder according to a certain proportion, wherein the preferred proportion is 1:1-1:5 by mass.
(3) Adding a binder into the mixed powder in the step (2), and stirring to fully mix the mixed powder.
(4) And (4) adding the powder fully mixed in the step (3) into a tablet press for pressing to obtain the sheet electrode.
(5) And (4) putting the sheet electrode pressed in the step (4) into a muffle furnace for binder solidification, taking out the sheet electrode after solidification, and cooling to room temperature in a dry environment.
(6) And (5) packaging the cooled sheet electrode in the step (5) by adopting high-temperature-resistant organic resin.
(7) And (4) soaking the sheet electrode packaged in the step (6) in a 2mol/L sulfuric acid solution for 24 hours for corrosion resistance test, and finishing the preparation of the sulfide ore working electrode if no corrosion phenomenon occurs.
In the method, the sulphide ore is one or more of chalcopyrite, arsenopyrite and molybdenite, and the sulphide ore powder in the step (1) is below 200 meshes; the carbon powder is one or more of graphite powder and conductive carbon black.
In the above method, the binder in step (3) is preferably PVDF (polyvinylidene fluoride), and accordingly, the binder in step (5) is cured at 80 ℃ for 12 hours.
The sulfide ore working electrode can be used for researching the pressure leaching process of sulfide ore: the sulfide ore to be researched is prepared into the sulfide ore working electrode, the sulfide ore working electrode is used as the working electrode, the leaching solution used in the research pressure leaching process is used as electrolyte, and the actual pressure leaching process of the sulfide ore can be simulated according to the pressure and the temperature of the actual pressure leaching process under reaction conditions. The electrochemical test is carried out on the working electrode, particularly the dynamic electrochemical test in the reaction process and before and after the reaction process, an electrochemical signal is obtained, and the test result is researched and analyzed, namely the electrochemical signal under the conditions of high temperature and high pressure in the actual pressure leaching process of the sulphide ore is simulated, analyzed and researched, so that the electrochemical mechanism of the pressure leaching process of the sulphide ore such as the chalcopyrite and the like at different temperatures is known, the kinetic parameters of each subprocess are obtained, and the forming and growing mechanism and the like of a surface passivation film of the chalcopyrite can be determined for the chalcopyrite.
The electrochemical test comprises common electrochemical tests such as an open-circuit potential test, a polarization curve test, an alternating-current impedance spectrum test and the like, and an electrochemical signal of the sulfide ore in the working electrode in the high-temperature high-pressure leaching process is obtained. The number of sub-processes in the leaching process can be distinguished by means of an alternating current impedance spectrum, the kinetic parameters of each sub-process can be obtained by means of methods such as equivalent circuit simulation of alternating current impedance, and the formation and growth mechanism of the chalcopyrite surface passivation film is determined.
The reaction of the working electrode in the electrolyte may be carried out in a closed vessel in order to control the reaction pressure and reduce the evaporation of water under high temperature conditions. In the electrochemical test requiring a three-electrode system (working electrode, counter electrode, reference electrode), the reference electrode may be disposed inside the closed container or outside the closed container. If the reference electrode is arranged inside, the reference electrode is called as an internal reference electrode, the internal reference electrode is also subjected to high temperature and high pressure, two internal reference electrodes can be arranged for monitoring whether the internal reference electrode fails or not, the potential difference between the two internal reference electrodes is tested in real time, and when the potential difference between the two internal reference electrodes is smaller, the electrodes are considered to be stable; when the potential difference is large (more than 5mV), it is considered that the electroactive substance in the reference electrode is hydrolyzed and the like, and at this time, the electroactive substance of the electrode needs to be replaced.
The invention has the beneficial effects that: the working electrode can be used for testing the electrochemical signals of the working electrode under the corresponding sulfide ore pressure leaching condition, particularly can be used for carrying out dynamic testing to obtain dynamic electrochemical signals in the whole reaction process, such as carrying out polarization curve testing, alternating current impedance spectrum testing and the like, and the obtained electrochemical testing result can be used for simulating and analyzing the actual pressure leaching process of sulfide ores, knowing the leaching electrochemical mechanism of the sulfide ores such as chalcopyrite and the like at different temperatures, obtaining the dynamic parameters of each sub-process of pressure leaching and determining the formation and growth mechanism of the chalcopyrite surface passivation film.
Drawings
FIG. 1 shows the chalcopyrite working electrode at different temperatures in example 1 at H 2 SO 4 Schematic diagram of the results of open circuit potential testing in solution;
FIG. 2 shows the chalcopyrite working electrode at different temperatures in example 1 at H 2 SO 4 Results of a polarization curve test in solution are shown schematically;
FIG. 3 is a graph showing the results of EIS testing of chalcopyrite working electrodes at different temperatures in example 1;
FIG. 4 is a plot of the polarization of the arsenopyrite working electrode of example 2 at various temperatures, and (b) is a partial enlargement of the electrode potential at 0.2-0.8V in (a);
FIG. 5 is a graph of Evens (Evans) at 100 ℃ and 160 ℃ for the arsenopyrite working electrode of example 2.
Detailed Description
For further understanding of the contents, features and advantages of the present invention, the following detailed description of the present invention is given in conjunction with the examples, which should not be construed as limiting the present invention.
Example 1
The study object of this example was chalcopyrite, and a working electrode comprising a chalcopyrite powder was prepared as follows:
(1) the chalcopyrite is pretreated (ore dressing and impurity removal) and crushed and ground to prepare 200-mesh chalcopyrite powder.
(2) An appropriate type of carbon powder, which is commercially available RC-69 high-purity conductive carbon black in this example, was selected and mixed with the chalcopyrite powder in a ratio of 1: 3.
(3) Adding PVDF as a binder into the mixed powder in the step (2), and stirring to fully mix the PVDF and the mixed powder.
(4) And (4) adding the fully mixed powder in the step (3) into a tablet press for pressing, wherein the diameter of a tablet pressing die of the tablet press is 1cm, and pressing into a sheet electrode with the diameter of 1 cm.
(5) And (4) putting the sheet electrode pressed in the step (4) into a muffle furnace for binder curing, wherein the curing conditions are 80 ℃ and 12 hours. And after solidification, taking out the sheet electrode, and cooling to room temperature in a dry environment.
(6) And (3) packaging the cooled sheet electrode in the step (5) by using a high-temperature-resistant organic resin, wherein the high-temperature-resistant organic resin used in the embodiment is a commercially available high-temperature-resistant glue 8301. The outer diameter of the encapsulated sheet electrode was 2.5 cm.
(7) And (4) soaking the packaged sheet electrode in the step (6) in a 2mol/L sulfuric acid solution for 24 hours for corrosion resistance test, wherein the corrosion phenomenon does not occur, and the preparation of the chalcopyrite working electrode for researching the chalcopyrite pressure leaching process is completed.
The electrode prepared by the method is used as a working electrode, a high-purity platinum wire is used as a counter electrode, and silver chloride are used as reference electrodes to perform electrochemical test of a three-electrode system. In order to simulate the actual pressure leaching process, the used electrolyte is 1.0mol/L sulfuric acid solution, the reaction of a working electrode in the electrolyte is carried out at the temperature of 30-150 ℃ and under the pressure of 0.8MPa, the electrochemical workstation for testing is a V3F model electrochemical workstation of Princeton company, the selected test closed pressure container is self-made high-temperature electrochemical testing equipment, the main body material is metal titanium, and high-temperature-resistant polytetrafluoroethylene is adopted as an insulating lining inside the test closed pressure container. And in the reaction process, the reference electrode is arranged in the container, two reference electrodes are adopted and the potential difference between the two reference electrodes is monitored, and once the potential difference between the two reference electrodes exceeds 5mV, the active substances in the reference electrodes are replaced.
The electrochemical tests performed included open circuit potential testing, polarization curve testing, alternating current impedance spectroscopy (EIS) testing, with the following test results and analysis results:
and (3) testing open circuit potential:
FIG. 1 is a curve of open circuit potential of chalcopyrite working electrode prepared by the method along with time at different temperatures. As can be seen, the open circuit potential of the chalcopyrite working electrode can gradually reach a stable value in the sulfuric acid solution at 30 ℃, 110 ℃, 130 ℃ and 150 ℃ along with the time, because a passivation film is formed on the surface of the chalcopyrite, and the thin passivation film is formed spontaneously in the preparation process of the chalcopyrite working electrode or in the process of stabilizing the open circuit potential. According to current research, the composition of the passivation film may be Cu1-xFe1-yS2 formed by the following chemical reaction:
CuFeS 2 →Cu 1-x Fe 1-y S 2 +xCu 2+ +yFe 2+ +2(x+y)e - ,y≥x,x+y≈1
at the temperature of 30 ℃, 110 ℃ and 130 ℃, the passivation film of the chalcopyrite in the sulfuric acid solution has the tendency of growing up and the open-circuit potential is increased. When the leaching temperature is 150 ℃, the thickness of the passivation film does not grow, which shows that the reaction resistance of the chalcopyrite leaching is smaller, and the leaching mechanism of the chalcopyrite is different due to different temperatures. According to the theory of mixed potential, it is assumed that when the cathode reaction rate does not change much, the reduction of the open-circuit potential means that the anodic oxidation current is increased, that is, the temperature is increased to cause the chalcopyrite working electrode to be at a higher oxidation leaching rate, the result is identical with the leaching experiment result, and the temperature is increased to be beneficial to the chalcopyrite leaching.
And (3) testing a polarization curve:
FIG. 2 shows chalcopyrite working electrode at different temperatures in H 2 SO 4 Polarization curves in solution, scan speed 1 mV/s. As can be seen, similar but not complete passivation was observed on the anodic polarization curves at 30 ℃ and 150 DEG CIn behavior, this phenomenon is often seen when the passivation film is converted from one form to another. Under the condition of 30 ℃, when the potential reaches 950mV, the current of the chalcopyrite working electrode begins to increase along with the increase of the potential, and over-passivation occurs, which indicates that a passivation film exists when the chalcopyrite is leached at normal temperature, and the passivation film is a metal-deficient sulfide (proved by the atmospheric pressure leaching XPS characterization of the chalcopyrite), and has the typical characteristics of a semiconductor; the anode sweep curve obtained from the test also shows the same tendency of passivation over-passivation when the test temperature is 150 ℃, but the over-passivation potential is smaller and is only 500 mV. CuFeS as main body phase in leached residues 2 In addition, it also contains a large amount of hematite (Fe) 2 O 3 ) And a small amount of pyrite (FeS) 2 ) And the result shows that the pyrite is generated after the decomposition of the chalcopyrite at the temperature. Potential 500mV, pH of solution<At 4, in CuFeS 2 -H 2 The potential-pH diagram of the O system is gradually changed from the stable region of pyrite to Fe 3+ The stable zone, the tendency of the over-passivation is probably that the pyrite attached to the surface of the chalcopyrite dissolves to cause the resistance layer to be thinned and the anode current to be increased.
After the anode curve shows the tendency of passivation and passivation dissolution, the corrosion current of the chalcopyrite working electrode at different temperatures can be calculated only by the Tafel method of the cathode polarization curve, and the results are shown in Table 1. From the calculation results, it is found that the self-corrosion potential (E) of the chalcopyrite working electrode is increased when the temperature is increased corr ) Gradually decreasing, self-corroding current (i) corr ) Gradually become larger, and the conclusion is consistent with the test results of OCP. Self-corrosion current (i) of chalcopyrite working electrode at 150 DEG C corr ) The leaching rate is improved by three orders of magnitude and is far greater than the leaching effect at 30 ℃, which can better explain that the temperature rise is beneficial to the dissolution of the chalcopyrite. Cathode Tafel slope (beta) of chalcopyrite working electrode c ) The absolute value of (A) gradually increases with increasing temperature, beta at a temperature of 150 DEG C c The absolute value reaches 387.4 mV/dec. The fact that the absolute value of the slope of the cathode Tafel is larger means that the reaction rate of the cathode is reduced, and the leaching mechanism of the chalcopyrite is changed.
TABLE 1 Tafel Square of chalcopyrite working electrode polarization curves at different temperaturesThe results of the equation fitting, including the self-corrosion potential (E) corr ) Self-etching current (i) corr ) Cathode Tafel slope (. beta.) c ) And anode Tafel slope (. beta.) a )
EIS test:
FIG. 3 shows the results of EIS measurements of chalcopyrite working electrodes at different temperatures. From the Bode model value diagram, the impedance value can be obviously reduced after the reaction temperature is increased, which shows that the resistance borne by the chalcopyrite leaching can be reduced by increasing the reaction temperature, and the result is consistent with the dynamic experiment result of the pressure leaching of the leached chalcopyrite.
When the temperature is 30 ℃, only one obvious time constant exists on a Bode phase diagram of a chalcopyrite EIS test, and a phase angle platform corresponding to the time constant platform is higher, about 70 ℃, generally indicating that a compact semiconductor passivation film is formed on the surface of the chalcopyrite, and researches show that the passivation film is mainly a metal-deficient sulfide and is caused by different migration rates of copper, iron and sulfur. When the temperature of the system rises, two time constants are represented in the Bode phase diagram, and the corresponding phase angle is low, which indicates that a porous and non-compact passivation film is formed on the surface of the chalcopyrite working electrode, and if the high temperature is favorable for chalcopyrite leaching, which is caused by the accelerated thermal motion of molecules, the EIS test result shows that the impedance value is only reduced, and the Bode phase diagram is not obviously changed. However, in the present study, the Bode phase diagram is significantly changed, further demonstrating that the leaching mechanism of chalcopyrite is changed.
As can be seen from the above electrochemical tests and result analyses, the dynamic electrochemical signal obtained by the chalcopyrite working electrode in this embodiment under the pressure leaching condition is well matched with the actual pressure leaching experimental result, and the variation trend of the electrochemical test result can correspond to the actual pressure leaching process, which indicates that the dynamic electrochemical test result obtained by using the working electrode in the present invention can be well used for the research and analysis of the actual pressure leaching process.
Example 2
The study object of this example was arsenopyrite, and a working electrode containing pyrite powder was prepared as follows:
(1) the arsenopyrite is pretreated (ore dressing and impurity removal) and crushed and ground to prepare 150-mesh arsenopyrite powder.
(2) Selecting a proper carbon powder type (RC-69 high-purity conductive carbon black sold in the market), and mixing the carbon powder with the arsenopyrite powder according to a ratio of 1: 4.
(3) Adding PVDF as a binder into the mixed powder in the step (2), and stirring to fully mix the PVDF and the mixed powder.
(4) And (4) adding the fully mixed powder in the step (3) into a tablet press for pressing, wherein the diameter of a tablet pressing die of the tablet press is 1cm, and pressing into a sheet electrode with the diameter of 1 cm.
(5) And (4) putting the sheet electrode pressed in the step (4) into a muffle furnace for binder curing, wherein the curing conditions are 80 ℃ and 12 hours. And after solidification, taking out the sheet electrode, and cooling to room temperature in a dry environment.
(6) And (3) packaging the cooled sheet electrode in the step (5) by using a high-temperature-resistant organic resin, wherein the high-temperature-resistant organic resin used in the embodiment is commercially available high-performance fiber 8301 high-temperature-resistant glue. The outer diameter of the encapsulated sheet electrode was 2.5 cm.
(7) And (4) soaking the packaged sheet electrode in the step (6) in a 2mol/L sulfuric acid solution for 24 hours for corrosion resistance test, wherein the corrosion phenomenon does not occur, and the preparation of the arsenopyrite working electrode for researching the arsenopyrite pressure leaching process is completed.
The electrode prepared by the method is used as a working electrode, a high-purity platinum wire is used as a counter electrode, and silver chloride are used as reference electrodes to perform electrochemical test of a three-electrode system. In order to simulate the actual pressure leaching process, the electrolyte is 1.0mol/L sulfuric acid solution, the reaction of the working electrode in the electrolyte is carried out under the conditions of 100 ℃, 120 ℃, 140 ℃ and 160 ℃ and the pressure is the saturated vapor pressure of water at the corresponding temperature, the electrochemical workstation for testing is a V3F model electrochemical workstation of Princeton company, the selected test closed pressure container is self-made high-temperature electrochemical test equipment, the main material is metallic titanium, and the interior adopts high-temperature resistant polytetrafluoroethylene as an insulating lining. And in the reaction process, the reference electrode is arranged in the container, two reference electrodes are adopted and the potential difference between the two reference electrodes is monitored, and once the potential difference between the two reference electrodes exceeds 5mV, the active substances in the reference electrodes are replaced.
The results of the polarization curves of the electrochemical tests are shown in fig. 4, and the analysis of the test results is as follows:
the polarization curve of the anode can be divided into three regions, taking the polarization curve of 120 ℃ as an example, when the potential is from E corr About 0.367V, the anode current density increases with increasing potential; when the potential is 0.367V-0.409V, the current density of the anode is obviously reduced along with the increase of the potential, which indicates that a passivation phenomenon occurs in the reaction process, and Fe is formed on the surface of arsenopyrite 1-x As 1－y S metal deficient sulfide layer or scorodite (FeAsO) 4 ·2H 2 O), thereby hindering the progress of the anodic reaction; when the potential is more than 0.409V, the anode current density of the reaction system is increased along with the increase of the potential, which indicates that the surface of the arsenopyrite is over-passivated, namely, the passivation film is dissolved under the condition of higher potential.
In addition, the passivation potentials at different temperatures are different, the passivation potential at 100 ℃ is 0.348V, the passivation potential at 120 ℃ is 0.363V, the passivation potential at 140 ℃ is 0.329V, the passivation phenomenon at 160 ℃ is not obvious, the passivation phenomenon on the surface of arsenopyrite is considered to be gradually weakened along with the increase of the temperature, the generation of metal-deficient sulfides is considered to be caused by the difference of the leaching rate and the migration rule of Fe and As, the metal-deficient sulfides can wrap the arsenopyrite, the passivation phenomenon is further generated, the oxidation capability of the system is enhanced along with the increase of the temperature, and more S is oxidized into SO 4 2- Thereby reducing the generation of a passivation film.
TABLE 1 Tafel equation fitting results for polarization curves of arsenopyrite working electrodes at different temperatures, including self-corrosion potential (E) corr ) Self-etching ofCurrent (i) corr ) Cathode Tafel slope (. beta.) c ) And anode Tafel slope (. beta.) a )
As can be seen from the table: the corrosion potential E of the arsenic pyrite working electrode in a sulfuric acid system is increased by the temperature corr Increase, corrosion current density i corr And is increased. This is consistent with the results of the thermodynamic validation test and the kinetic test. In addition, the temperature rises, anode beta a Decrease, indicating an increase in temperature and an increase in the rate of anodic reaction; while the temperature rises, the cathode beta c An increase in absolute value of (a) indicates that the cathode reaction rate decreases with increasing temperature. The Evans diagram in FIG. 5 shows that the change in the reaction rates of the cathode and anode together lead to the corrosion potential E corr And corrosion current density i corr Increasing with increasing temperature.
Claims (9)
1. The preparation method of the working electrode for the sulfide ore is characterized by comprising the following steps of:
(1) pretreating, crushing and grinding the sulfide ore to prepare sulfide ore powder;
(2) mixing carbon powder and the sulfide ore powder according to a certain proportion to prepare mixed powder;
(3) adding a binder PVDF into the mixed powder in the step (2), and stirring to fully mix the binder PVDF;
(4) Adding the powder fully mixed in the step (3) into a tablet press for pressing to obtain a sheet electrode;
(5) putting the sheet electrode pressed in the step (4) into a muffle furnace for binder solidification, and taking out the sheet electrode after solidification and cooling to room temperature;
(6) packaging the cooled sheet electrode in the step (5) by adopting high-temperature-resistant organic resin;
(7) and (4) soaking the sheet electrode packaged in the step (6) in a 2mol/L sulfuric acid solution for 24 hours for corrosion resistance test, and finishing the preparation of the sulfide ore working electrode if a large corrosion phenomenon does not occur.
2. The method for preparing the sulfide ore working electrode according to claim 1, wherein the sulfide ore is one or more of chalcopyrite, arsenopyrite and molybdenite, and the granularity of the sulfide ore powder in the step (1) is less than 200 meshes; the carbon powder is one or more of graphite powder and conductive carbon black.
3. The method for preparing the sulfide ore working electrode according to claim 1, wherein the mixing ratio of the carbon powder to the sulfide ore powder in the step (2) is 1:1-1:5 by mass.
4. The method for preparing a working electrode for a sulfide ore according to claim 1, wherein the curing condition of the binder in the step (5) is 80 ℃ and 12 hours.
5. A sulphide ore working electrode produced using the method of producing a sulphide ore working electrode according to any one of claims 1 to 4.
6. A method for researching the pressure leaching process of sulfide ore, which is characterized in that sulfide ore powder to be researched is prepared into the sulfide ore working electrode according to claim 5, the sulfide ore working electrode is taken as the working electrode, leachate of the researched pressure leaching process is taken as electrolyte, the pressure and the temperature of the researched pressure leaching process are taken as reaction conditions, the working electrode is immersed in the electrolyte for reaction, electrochemical test is carried out on the working electrode, and the test result is analyzed.
7. The method for researching the pressure leaching process of the sulfide ore according to claim 6, wherein the reaction of the working electrode in the electrolyte is carried out in a closed container, the electrochemical signal measurement adopts a three-electrode system, reference electrodes in the three-electrode system are arranged in the closed container, and the number of the reference electrodes is 2; when performing electrochemical signal measurements, the active material in 2 reference electrodes is replaced if the potential difference between the two reference electrodes is greater than 5 mV.
8. The method for researching the pressure leaching process of the sulfide ore according to claim 6, wherein the electrochemical test is a dynamic electrochemical test of the working electrode in the electrolyte during and before the reaction process.
9. The method of investigating a process of pressure leaching a sulphide ore according to claim 6 wherein the electrochemical test comprises an open circuit potential test, a polarisation curve test, an AC impedance spectroscopy test.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011600450.6A CN112782250B (en) | 2020-12-29 | 2020-12-29 | Preparation method of sulfide ore working electrode, working electrode and research method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202011600450.6A CN112782250B (en) | 2020-12-29 | 2020-12-29 | Preparation method of sulfide ore working electrode, working electrode and research method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112782250A CN112782250A (en) | 2021-05-11 |
| CN112782250B true CN112782250B (en) | 2022-07-29 |
Family
ID=75751497
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202011600450.6A Active CN112782250B (en) | 2020-12-29 | 2020-12-29 | Preparation method of sulfide ore working electrode, working electrode and research method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112782250B (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113241425B (en) * | 2021-06-03 | 2021-11-23 | 贵州民族大学 | Molybdenite electrode and preparation method thereof |
| CN116106209A (en) * | 2023-02-16 | 2023-05-12 | 中国科学院地球化学研究所 | Electrode containing gold poison sand and preparation method thereof |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106268514A (en) * | 2016-09-09 | 2017-01-04 | 东北大学 | A kind of multifunctional analysis autoclave and using method thereof |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1020519C (en) * | 1990-01-23 | 1993-05-05 | 冶金工业部长沙矿冶研究院 | Moisture sensitive resistance element and method for manufacturing the same |
| CN105858816B (en) * | 2016-03-31 | 2018-10-19 | 西南石油大学 | A kind of pyrolusite/graphite powder compound particle electrode and preparation method |
| CN105973796B (en) * | 2016-06-24 | 2019-03-08 | 中国科学院地球化学研究所 | A kind of preparation method of chalcopyrite electrode |
| CN106044867B (en) * | 2016-06-24 | 2018-02-13 | 中国科学院地球化学研究所 | A kind of preparation method of pyrite electrode |
| CN111751436A (en) * | 2020-07-08 | 2020-10-09 | 中国科学院地球化学研究所 | Method for rapidly predicting and evaluating arsenic release pollution influence of meadow soil containing arsenic pyrite |
-
2020
- 2020-12-29 CN CN202011600450.6A patent/CN112782250B/en active Active
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN106268514A (en) * | 2016-09-09 | 2017-01-04 | 东北大学 | A kind of multifunctional analysis autoclave and using method thereof |
Non-Patent Citations (2)
| Title |
|---|
| 王少芬等.碳糊电极在硫化矿发电浸出过程中的应用研究.《电化学》.2005,(第01期), * |
| 碳糊电极在硫化矿发电浸出过程中的应用研究;王少芬等;《电化学》;20050228(第01期);第77-82页 * |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112782250A (en) | 2021-05-11 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN112782250B (en) | Preparation method of sulfide ore working electrode, working electrode and research method | |
| Cruz et al. | An experimental strategy to determine galvanic interactions affecting the reactivity of sulfide mineral concentrates | |
| Warren et al. | Passive and transpassive anodic behavior of chalcopyrite in acid solutions | |
| Serghini-Idrissi et al. | Electrochemical and spectroscopic characterizations of patinas formed on an archaeological bronze coin | |
| Bach et al. | A Thermodynamic and Kinetic Study of Electrochemical Lithium Intercalation in Na0. 33 V 2 O 5 Bronze Prepared by a Sol‐Gel Process | |
| Mahato | The Cyclic Corrosion of the Lead‐Acid Battery Positive | |
| Fu et al. | Influence of moisture on corrosion behaviour of steel ground rods in mildly desertified soil | |
| Zhang et al. | Electrochemical performance of sulfide solid electrolyte Li10GeP2S12 synthesized by a new method | |
| Karimi et al. | The mechanism of electrochemical dissolution of sphalerite in sulfuric acid media | |
| Liu et al. | Electrochemical study of hydrothermal and sedimentary pyrite dissolution | |
| Xu et al. | Research on microstructure of membrane-slime layer on lead-based anode surface in zinc hydrometallurgy by combining μ-XRF with mm-XRF | |
| CN107024662A (en) | A kind of analysis test method of charging and discharging lithium battery performance and Mechanism of electrochemical behaviors of anhydrous | |
| Madhuchhanda et al. | Galvanic interaction between sulfide minerals and pyrolusite | |
| Warner et al. | An electrochemical study of the oxidative dissolution of synthetic pentlandite in aqueous media | |
| Sugae et al. | Electrochemical reduction and re‐oxidation behavior of α, β, and γ‐iron oxy‐hydroxide films on electrodes | |
| Dyer et al. | On the refractory nature of precious metal tellurides | |
| Fan et al. | Preparation of Metal Lead from Waste Lead Paste by Direct Electrochemical Reduction in NH 3-NH 4 Cl Solution | |
| Murthy et al. | Preparation and characterization of some lithium–Ion conductors | |
| Khatbi et al. | Electrochemical and metallurgical behavior of lead-aluminum casting alloys as grids for lead-acid batteries | |
| Kim et al. | Cobalt electrodeposition from cobalt chloride using urea and choline chloride ionic liquid: effect of temperature, applied voltage, and cobalt chloride concentration on current efficiency and energy consumption | |
| Etienne | Electrochemical aspects of the aqueous oxidation of copper sulphides | |
| Jarjoura et al. | Effect of nickel on copper anode passivation in a copper sulfate solution by electrochemical impedance spectroscopy | |
| Tjelta et al. | Electrochemistry of Mackinawite Electrodes in Sour Aqueous Solutions | |
| Quan et al. | Study on CorroSion Behavior of Q235 Steel and 16Mn Steel By eleCtroCheMiCal and Weight loSS Method | |
| Giel et al. | Investigations of the Li8Sn3 phase in the binary Li-Sn system using an improved coulometric-titration setup |
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 |