A method for preparing electrolytic cobalt by circulating hydrochloric acid

Abstract

The invention relates to the technical field of electrolytic cobalt preparation, and discloses a method for preparing electrolytic cobalt by circulating hydrochloric acid. The method comprises the following steps: dynamically collecting current density in an electrolytic process, identifying the amount of deposits in the electrolytic process based on current density data, and obtaining a current density verification signal according to the degree of deviation of the amount of deposits; segmenting the electrolytic process time based on the current density verification signal, intercepting a reference current density corresponding to each unit time to construct a current density curve, and intercepting an electrolyte temperature corresponding to each unit time to construct an electrolyte temperature curve; comparing the current density curve with the electrolyte temperature curve to obtain a standard electrolyte temperature interval based on the current density, and completing dynamic correction of the electrolyte temperature and current density in the electrolytic process according to the standard electrolyte temperature interval, so as to achieve a good electrolytic state and obtain electrode cobalt with good quality.

Description

Technical Field

[0001] The invention relates to the technical field of electrolytic cobalt preparation, and in particular to a method for preparing electrolytic cobalt by circulating hydrochloric acid. Background Art

[0002] Cobalt has excellent properties such as corrosion resistance, high melting point and strong magnetism. It is an important raw material for the production of various special steels, heat-resistant alloys, corrosion-resistant alloys, magnetic alloys, etc.

[0003] Cobalt production is generally carried out by the electrolytic method, which mainly involves using cobalt concentrate, cobalt-copper alloy or crude cobalt salt as raw materials, preparing high-purity electrolytic cobalt through a series of chemical reactions and electrolysis processes, and realizing the recycling of hydrochloric acid.

[0004] During the electrolytic deposition process, the current density directly affects the deposition rate, the quality of the deposited layer (such as purity, crystal morphology, smoothness, etc.) and energy consumption. Therefore, the current density needs to be effectively controlled. In the process of controlling the current density, it is usually achieved by selecting appropriate electrolytic deposition process conditions, that is, by selecting a reasonable electrolyte formula, optimizing the electrolytic cell structure and adjusting the shape of the working electrode. These adjustments are optimized before the start of electrolytic deposition. However, during the electrolytic deposition process, how to adjust the electrode density to reach the appropriate current density range is a technical problem that needs to be solved urgently.

[0005] Based on this, the present application proposes a method for preparing electrolytic cobalt by circulating hydrochloric acid. Summary of the invention

[0006] The object of the present invention is to provide a method for preparing electrolytic cobalt by hydrochloric acid circulation, integrating the electrolyte temperatures corresponding to the current density standard units to obtain a first electrolyte temperature standard range, integrating the electrolyte temperatures corresponding to the electrolyte standard units to obtain a second electrolyte temperature standard range, overlapping the temperature range based on current density with the temperature range based on electrolyte temperature, that is, narrowing the temperature range to obtain the electrolyte temperature standard range during the electrolytic process.

[0007] The purpose of the present invention can be achieved by the following technical solutions:

[0008] A method for preparing electrolytic cobalt by circulating hydrochloric acid, comprising the following steps:

[0009] Using cobalt concentrate, cobalt-copper alloy or crude cobalt salt as raw materials, leaching with sulfuric acid or hydrochloric acid to obtain a leachate containing cobalt ions;

[0010] Purifying the leaching solution, extracting cobalt from the purified leaching solution using a P507 extractant to obtain a cobalt extract;

[0011] The cobalt extract is stripped with hydrochloric acid to obtain a cobalt chloride solution, and the cobalt chloride solution is deoiled and mixed with an electrolytic solution to obtain an electrolytic pre-solution;

[0012] Electrodeposition is performed on the pre-electrodeposition solution, and the current density is dynamically collected during the electrodeposition process. The amount of deposits in the electrodeposition is identified based on the current density data, and a current density verification signal is obtained according to the degree of deviation of the amount of deposits.

[0013] Based on the current density calibration signal, the electroplating time is processed in segments, the reference current density corresponding to each unit time is intercepted to construct a current density curve, and the electrolyte temperature corresponding to each unit time is intercepted to construct an electrolyte temperature curve;

[0014] The current density curve is compared with the electrolyte temperature curve to obtain the electrolyte temperature standard range based on the current density, and the electrolyte temperature and current density of the electrolytic deposition process are dynamically corrected according to the electrolyte temperature standard range;

[0015] Cobalt ions are reduced to metallic cobalt at the cathode and oxidized to obtain chlorine at the anode. The obtained chlorine and the post-electrolysis liquid are introduced into the electrolysis liquid circulation tank, and the chlorine and the electrolysis liquid are separated by the gas-liquid separator.

[0016] The chlorine gas is dried, and the dried chlorine gas is subjected to a synthesis reaction with hydrogen to obtain hydrogen chloride, which is absorbed by pure water to obtain hydrochloric acid, and the generated hydrochloric acid is returned to the P507 stripping process for reuse.

[0017] As a further solution of the present invention: during the electrowinning process, the quality of the deposit on the electrode is processed;

[0018] That is, through the formula The actual mass m of sediment is calculated by the formula;

[0019] Where n is the electron transfer number of the deposited material, F is the Faraday constant, M is the molar mass of the deposited material, It is the total amount of charge passing through the electrode from time 0 to time t during the electrolysis process.

[0020] As a further solution of the present invention: the sediment deviation amount is compared with the sediment deviation amount threshold value;

[0021] If the deposit deviation is greater than or equal to the deposit deviation threshold, it means that the current density performance fluctuates during the electroplating process, and a current density verification signal is generated;

[0022] If the deposit deviation is less than the deposit deviation threshold, it means that the current density is normal during the electroplating process, and a normal current density signal is generated.

[0023] As a further solution of the present invention: verifying the signal based on the current density;

[0024] The duration of the electrolytic process is divided into a number of time units, and the current density and electrolyte temperature corresponding to the middle moment of each time unit are obtained;

[0025] Construct a two-dimensional coordinate system of current density-time unit, and construct a current density curve based on the current density corresponding to the middle moment of each time unit;

[0026] Obtaining the abnormal area of ​​the upper current density and the abnormal area of ​​the lower current density;

[0027] Constructing a two-dimensional coordinate system of electrolyte temperature-time unit, and constructing an electrolyte temperature curve with the electrolyte temperature corresponding to the middle moment of each time unit;

[0028] Obtain the abnormal area on the electrolyte temperature and the abnormal area under the electrolyte temperature.

[0029] As a further solution of the present invention: obtaining the abnormal current density upper time period corresponding to the abnormal current density upper region and the abnormal current density lower time period corresponding to the abnormal current density upper region;

[0030] Obtaining the abnormal time period of the electrolyte temperature corresponding to the abnormal area of ​​the electrolyte temperature and the abnormal time period of the electrolyte temperature corresponding to the abnormal area of ​​the electrolyte temperature;

[0031] Obtaining the abnormal characterization ratio of the current density and the time in the abnormal area of ​​the electrolyte temperature;

[0032] Obtain the lower abnormal characterization ratio of the current density and the abnormal region time at the electrolyte temperature;

[0033] The upper abnormal characterization ratio and the lower abnormal characterization ratio are processed to obtain the abnormal overlap characterization value.

[0034] As a further solution of the present invention: the abnormal overlap characterization value SX is compared with the abnormal overlap characterization threshold sx;

[0035] If the abnormal overlap characterization value SX is greater than or equal to the abnormal overlap characterization threshold sx, it means that the abnormal current density in the electrolytic deposition process is associated with the abnormal electrolyte temperature, and a coordinated control signal is generated;

[0036] If the abnormal overlap characterization value SX is less than the abnormal overlap characterization threshold sx, it means that there is no correlation between the abnormal current density and the abnormal electrolyte temperature during the electrolysis process, and a non-cooperative control signal is generated.

[0037] As a further solution of the present invention: the process of obtaining the current density corresponding to the middle moment of the time unit is:

[0038] Obtain the current corresponding to the middle moment of each time unit during the electrolytic deposition process, denoted as I;

[0039] Obtain the electrolytic deposition area during the electrolytic deposition process, recorded as A;

[0040] That is, through the formula The current density Ji corresponding to the middle moment of each time unit is calculated, where k is the electrode surface interference factor, i is the number of time units, i=1, 2, ..., m.

[0041] As a further solution of the present invention: the process of obtaining the interference factor on the electrode surface is:

[0042] Identify the roughness and contamination degree of the electrode surface;

[0043] The reference current density of the corresponding electrode without the influence of roughness and pollution is recorded as Jc;

[0044] By formula The reference current density of the corresponding electrode under the influence of roughness and pollution is recorded as Jw, where g(R) is a function describing the influence of roughness on current density, and h(P) is a function describing the influence of pollution degree on current density;

[0045] The electrode surface interference factor k is obtained by calculating the ratio of the reference current density Jw of the corresponding electrode when there is roughness and pollution influence and the reference current density Jc of the corresponding electrode when there is no roughness and pollution influence.

[0046] As a further solution of the present invention: based on the synergistic regulatory signal;

[0047] Obtain all time units corresponding to the area of ​​the current density curve between the upper boundary of the current density and the lower boundary of the current density, and record them as current density standard units;

[0048] Obtain the maximum value C1max and the minimum value C1min of the electrolyte temperature corresponding to the current density standard unit, that is, obtain the first electrolyte temperature standard interval [C1min, C1max] during the electrolytic deposition process;

[0049] Obtain all time units corresponding to the area of ​​the electrolyte temperature curve between the electrolyte temperature upper limit and the electrolyte temperature lower limit, and record them as electrolyte temperature standard units;

[0050] Obtain the maximum electrolyte temperature C2max and the minimum electrolyte temperature C2min corresponding to the electrolyte temperature standard unit, that is, obtain the second electrolyte temperature standard interval [C2min, C2max] during the electrolytic deposition process;

[0051] The first standard temperature interval [C1min, C1max] of the electrolyte during the electrolysis process is overlapped with the second standard temperature interval [C2min, C2max] of the electrolyte during the electrolysis process to obtain the electrolyte overlap temperature interval, that is, the electrolyte temperature standard interval [Cmin, Cmax] during the electrolysis process.

[0052] As a further solution of the present invention: marking the time unit in which the electrolyte temperature is within the electrolyte temperature standard interval [Cmin, Cmax] as the approved time unit;

[0053] Obtain the maximum current density Jmax and the minimum current density Jmin corresponding to the approved time unit, that is, obtain the standard current density range [Jmin, Jmax] during the electrolytic deposition process;

[0054] Obtain the temperature range value within the standard range [Cmin, Cmax] of the electrolyte temperature during the electrolytic deposition process;

[0055] Obtain the current density interval value within the current density standard interval [Jmin, Jmax] during the electrowinning process;

[0056] The temperature interval value and the current density interval value are ratio-calculated to obtain the temperature-electric density correlation coefficient. The current density deviation value and the temperature-electric density correlation coefficient are calculated to obtain the temperature adjustment value of the electrolyte temperature. The electrolyte temperature is dynamically adjusted through an external temperature adjustment device.

[0057] Beneficial effects of the present invention:

[0058] (1) The present invention dynamically collects the current density during the electrolysis process, identifies the amount of deposits in the electrolysis based on the current density data, obtains a current density verification signal according to the degree of deviation of the amount of deposits, and processes the electrolysis time in segments based on the current density verification signal, integrates the effects of roughness and contamination on the electrode current density, extracts the reference current density corresponding to each unit time to construct a current density curve, extracts the electrolyte temperature corresponding to each unit time to construct an electrolyte temperature curve, and compares the current density curve with the electrolyte temperature curve.

[0059] Obtain the overlap state of the unqualified interval and the qualified interval of the current density curve and the electrolyte temperature curve, perform comparison processing based on the overlap state, obtain the electrolyte temperature standard interval based on the current density, and complete the dynamic correction of the electrolyte temperature and current density of the electrolytic deposition process according to the electrolyte temperature standard interval;

[0060] (2) In the process of overlapping the unqualified intervals of the current density curve and the electrolyte temperature curve, the present invention obtains the time overlap degree of the unqualified intervals of the current density curve and the electrolyte temperature curve with the same trend, that is, the abnormal time period corresponding to the unstable (abnormal) current density and the abnormal time period corresponding to the unstable (abnormal) electrolyte temperature have a high overlap rate, and it can be deduced that there is a correlation between the unstable current density and the unstable electrolyte temperature, and the influence of the electrolyte temperature and the current density is determined;

[0061] (3) The present invention obtains the current density standard unit corresponding to the qualified current density, integrates the electrolyte temperature corresponding to the current density standard unit, and obtains the first electrolyte temperature standard interval (indicating that the current density in the electrolysis process is up to standard within this temperature interval), and then reversely derives to obtain the electrolyte temperature standard unit corresponding to the qualified electrolyte temperature, integrates the electrolyte temperature corresponding to the electrolyte standard unit, and obtains the second electrolyte temperature standard interval (indicating that the electrolyte temperature in the electrolysis process is up to standard within this temperature interval), that is, by overlapping the temperature interval with the current density as the object with the temperature interval with the electrolyte temperature as the object, that is, narrowing the temperature interval to obtain the electrolyte temperature standard interval in the electrolysis process, and achieving the electrolyte temperature and the temperature required for the qualified current density within this electrolyte temperature standard interval.

[0062] (4) In the actual regulation process of current density of the present invention, when there is a deviation between the actual current density and the preset current density (not meeting the requirements), the deviation value of the current density is calculated with the temperature-electricity density correlation coefficient to obtain the temperature adjustment value of the electrolyte temperature. The electrolyte temperature is dynamically adjusted through an external temperature adjustment device to realize online correction of the current density and the electrolyte temperature during the electrolysis process to achieve a good electrolysis state. BRIEF DESCRIPTION OF THE DRAWINGS

[0063] The present invention will be further described below in conjunction with the accompanying drawings.

[0064] Figure 1 This is a flow chart of a method for preparing electrolytic cobalt by circulating hydrochloric acid according to an embodiment of the present invention;

[0065] Figure 2 This is a flow chart for identifying the amount of sediment in the preparation of electrolytic cobalt by circulating hydrochloric acid according to an embodiment of the present invention;

[0066] Figure 3 This is a flow chart of obtaining a coordinated control signal in preparing electrolytic cobalt by hydrochloric acid circulation according to an embodiment of the present invention;

[0067] Figure 4 The present invention is a flowchart for obtaining a standard range of electrolyte temperature in the preparation of electrolytic cobalt by hydrochloric acid circulation according to an embodiment of the present invention. DETAILED DESCRIPTION

[0068] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0069] Example 1

[0070] See also Figure 1 As shown, the present invention is a method for preparing electrolytic cobalt by circulating hydrochloric acid, comprising the following steps:

[0071] Using cobalt concentrate, cobalt-copper alloy or crude cobalt salt as raw materials, leaching with sulfuric acid or hydrochloric acid to obtain a leachate containing cobalt ions;

[0072] Purifying the leaching solution, extracting cobalt from the purified leaching solution using a P507 extractant to obtain a cobalt extract;

[0073] The cobalt extract is stripped with hydrochloric acid to obtain a cobalt chloride solution, and the cobalt chloride solution is deoiled and mixed with an electrolytic solution to obtain an electrolytic pre-solution;

[0074] Electrodeposition is performed on the pre-electrodeposition solution, and the current density is dynamically collected during the electrodeposition process. The amount of deposits in the electrodeposition is identified based on the current density data, and a current density verification signal is obtained according to the degree of deviation of the amount of deposits.

[0075] Based on the current density calibration signal, the electroplating time is processed in segments, the reference current density corresponding to each unit time is intercepted to construct a current density curve, and the electrolyte temperature corresponding to each unit time is intercepted to construct an electrolyte temperature curve;

[0076] The current density curve is compared with the electrolyte temperature curve to obtain the electrolyte temperature standard range based on the current density, and the electrolyte temperature and current density of the electrolytic deposition process are dynamically corrected according to the electrolyte temperature standard range;

[0077] Cobalt ions are reduced to metallic cobalt at the cathode and oxidized to obtain chlorine at the anode. The obtained chlorine and the post-electrolysis liquid are introduced into the electrolysis liquid circulation tank, and the chlorine and the electrolysis liquid are separated by the gas-liquid separator.

[0078] The chlorine gas is dried, and the dried chlorine gas is subjected to a synthesis reaction with hydrogen to obtain hydrogen chloride, which is absorbed by pure water to obtain hydrochloric acid, and the generated hydrochloric acid is returned to the P507 stripping process for reuse.

[0079] Example 2

[0080] This embodiment is based on the embodiment 1. In the electrolytic deposition process, the control of current density is very important because the current density directly affects the deposition rate, the quality of the deposited layer (such as purity, crystal morphology, smoothness, etc.) and energy consumption;

[0081] During the electrochemical deposition process, since the current density changes with time due to a variety of factors (changes in electrolyte concentration, changes in electrode surface, changes in temperature, etc.);

[0082] Based on this, the current density is set as a function of time, that is, , J is the current density;

[0083] The total charge passing through the electrode during the electrowinning process is determined by integrating the current density as a function of time;

[0084] That is, through the formula Calculate the total charge Q passing through the electrode from time 0 to time t;

[0085] Based on Faraday's law, it is known that the amount of electricity in the electrolytic cell during electrolysis is proportional to the amount of material precipitated or dissolved on the electrode;

[0086] The mass of the deposit on the electrode needs to be calculated;

[0087] That is, through the formula The actual mass m of the sediment is calculated by the formula, where n is the number of electron transfers of the sediment material, F is the Faraday constant (approximately equal to 96485C / mol), and M is the molar mass of the sediment material;

[0088] That is, deformation can be obtained ;

[0089] See also Figure 2 , the actual mass of sediment and the theoretical precipitation amount of sediment are subjected to difference processing and the absolute value is taken to obtain the sediment deviation amount, and the sediment deviation amount is compared with the sediment deviation amount threshold value;

[0090] If the deposit deviation is greater than or equal to the deposit deviation threshold, it means that the current density performance fluctuates during the electroplating process, and a current density verification signal is generated;

[0091] If the deposit deviation is less than the deposit deviation threshold, it means that the current density is normal during the electroplating process, and a normal current density signal is generated.

[0092] Among them, the theoretical precipitation amount of sediment is set by the staff based on experience. This is because too high a sediment mass may also lead to excessive coverage of the electrode surface, affecting the uniformity and adhesion of the sediment layer, and even causing damage to the electrode structure; too low a sediment mass may lead to uneven distribution of the sediment layer on the electrode surface, affecting the quality and performance of the product;

[0093] Among them, the sediment deviation threshold is set by staff based on experience.

[0094] Example 3

[0095] Based on the current density verification signal obtained in Example 2, the current density is verified;

[0096] In actual operation, the current density cannot be too high or too low. Too high current density may lead to uneven deposition of metal ions, enhanced hydrogen evolution side reaction, and pinholes or sponge-like inclusions in the deposited layer. Too low current density will lead to too long deposition cycle, low production efficiency and increased energy consumption.

[0097] Based on this, the current density during the electrowinning process is monitored online, specifically:

[0098] Divide the duration of the electrolytic deposition process into several time units, and obtain the current density corresponding to the middle moment of each time unit;

[0099] Among them, the process of obtaining the current density corresponding to the middle moment of each time unit is:

[0100] Obtain the current corresponding to the middle moment of each time unit during the electrolytic deposition process, denoted as I;

[0101] Obtain the electrolytic deposition area during the electrolytic deposition process, recorded as A;

[0102] That is, through the formula The current density Ji corresponding to the middle moment of each time unit is calculated, where k is the electrode surface interference factor, i is the number of time units, i=1, 2, ..., m.

[0103] The surface state of the electrode, such as roughness and contamination, will affect the distribution of current density and the uniformity of the electrolytic reaction. Based on this, the electrode surface interference factor characterized by the electrode surface state is incorporated into the current density processing process;

[0104] The process of obtaining the interference factor on the electrode surface is as follows:

[0105] Identify the roughness and contamination degree of the electrode surface;

[0106] The reference current density of the corresponding electrode without the influence of roughness and pollution is recorded as Jc;

[0107] By formula The reference current density of the corresponding electrode under the influence of roughness and pollution is recorded as Jw, where g(R) is a function describing the influence of roughness on current density, and h(P) is a function describing the influence of pollution degree on current density;

[0108] The electrode surface interference factor k is obtained by calculating the ratio of the reference current density Jw of the corresponding electrode when there is roughness and pollution influence and the reference current density Jc of the corresponding electrode when there is no roughness and pollution influence.

[0109] Among them, the acquisition process of the function g(R) of the influence of roughness on current density is:

[0110] Obtain multiple groups of electrodes with different roughnesses, and determine the roughness R of the electrodes and the corresponding current density under the same electroplating conditions;

[0111] The g(R) function is constructed based on multiple groups of electrodes with different roughness;

[0112] Wherein, the g(R) function may be a polynomial function, an exponential function, a logarithmic function or a combination thereof;

[0113] Then, the parameters in the g(R) function are fitted by the least squares method based on multiple sets of experimental data (electrode roughness and corresponding current density);

[0114] Through continuous iteration and optimization, an optimal set of parameters is found so that the g(R) function can accurately describe the experimental data.

[0115] Among them, the process of obtaining the function h(P) of the influence of pollution degree on current density is:

[0116] Obtain multiple groups of electrode surfaces with different pollution levels, record the pollution level of the electrode surface as P, and determine the pollution level R of the electrode surface and the corresponding current density under the same electrolytic conditions;

[0117] Construct h(P) function based on multiple groups of electrodes with different pollution levels;

[0118] Wherein, the h(P) function may be a polynomial function, an exponential function, a logarithmic function or a combination thereof;

[0119] Then, the parameters in the g(R) function are fitted by the least squares method based on multiple sets of experimental data (the degree of contamination on the electrode surface and the corresponding current density);

[0120] Through continuous iteration and optimization, an optimal set of parameters is found so that the g(R) function can accurately describe the experimental data.

[0121] Example 4

[0122] Based on Example 3, the state of current density during the electrowinning process is identified;

[0123] During the electrowinning process, the current density at different time units is processed;

[0124] A two-dimensional coordinate system is constructed with time as the X-axis and current density as the Y-axis;

[0125] In the coordinate system, the middle moment of each time unit is used as the horizontal coordinate and the corresponding current density is used as the vertical coordinate to plot points, and the coordinate point corresponding to each time unit in the coordinate system is obtained;

[0126] Connect the coordinate points corresponding to all time units in the coordinate system from left to right to construct a current density curve;

[0127] Obtain the rated range value of the current density, and draw two parallel lines parallel to the X-axis for the two end points of the rated range value of the current density, which are recorded as the upper limit line of the current density and the lower limit line of the current density;

[0128] The area where the current density curve is obtained and located above the upper limit of the current density is recorded as the abnormal area on the current density;

[0129] The area of ​​the current density curve below the lower limit of the current density is obtained, which is recorded as the abnormal area under the current density;

[0130] The upper abnormal current density region and the lower abnormal current density region indicate that the current density in the corresponding time period exceeds a preset current density rated range value, and the current density is abnormal.

[0131] Since abnormal electrolyte temperature during electrolysis can cause the current density of the electrode to fluctuate during electrolysis, resulting in abnormal current density, it is necessary to analyze and determine whether the abnormal electrolyte temperature during electrolysis is related to the abnormal fluctuation of current density. If there is a relationship between the electrolyte temperature and the abnormal current density, it is convenient to adjust the electrolyte temperature in a timely and effective manner during the subsequent electrolysis process, reduce the abnormal electrolysis caused by unstable current density during electrolysis, and effectively improve the quality of metal cobalt during electrolysis. Specifically:

[0132] During the electrowinning process, the electrolyte temperature is processed at different time units;

[0133] A two-dimensional coordinate system is constructed with time as the X-axis and electrolyte temperature as the Y-axis;

[0134] In the coordinate system, the middle moment of each time unit is used as the horizontal coordinate and the corresponding electrolyte temperature is used as the vertical coordinate to plot points, and the coordinate point corresponding to each time unit in the coordinate system is obtained;

[0135] Connect the coordinate points corresponding to all time units in the coordinate system from left to right to construct the electrolyte temperature curve;

[0136] Obtain the rated range value of the electrolyte temperature, and draw two parallel lines parallel to the X-axis for the two end points of the rated range value of the electrolyte temperature, which are recorded as the upper limit line of the electrolyte temperature and the lower limit line of the electrolyte temperature;

[0137] Obtaining an area of ​​the electrolyte temperature curve that is above the electrolyte temperature upper limit line, which is recorded as an abnormal electrolyte temperature area;

[0138] Obtaining an area of ​​the electrolyte temperature curve below the electrolyte temperature boundary, which is recorded as an abnormal area of ​​the electrolyte temperature;

[0139] The rated range of electrolyte temperature is set by staff based on experience. This is because too high electrolyte temperature will cause serious volatilization of the electrolyte, increase energy consumption, deteriorate the working environment, make the cathode deposition crystals coarser, and affect the quality and uniformity of the deposited layer. Too low electrolyte temperature will cause the solubility of components in the solution to decrease, affecting the precipitation of electrolytic products, and reducing the electrodeposition capacity of the deposited layer, reducing the cathode current efficiency, causing crystallization in the electrolytic cell, and incomplete coating of the deposited layer.

[0140] Obtaining the abnormal current density time period corresponding to the abnormal current density region;

[0141] Obtain the abnormal time period of the current density corresponding to the abnormal area of ​​the current density;

[0142] The upper (lower) abnormal time period of the current density is obtained by drawing a perpendicular line from the end point of the corresponding abnormal area to the X-axis on the coordinate system and intersecting the X-axis. The time between the two intersection points on the X-axis is the abnormal time period of the corresponding abnormal area.

[0143] Obtaining the abnormal time period of the electrolyte temperature corresponding to the abnormal area of ​​the electrolyte temperature;

[0144] Obtaining the abnormal time period of the electrolyte temperature corresponding to the abnormal area of ​​the electrolyte temperature;

[0145] The upper (lower) abnormal time period of the electrolyte temperature is obtained by drawing a perpendicular line from the end point of the corresponding abnormal area to the X-axis on the coordinate system and intersecting the X-axis. The time between the two intersection points on the X-axis is the abnormal time period of the corresponding abnormal area.

[0146] Compare and process the abnormal time period of current density with the abnormal time period of electrolyte temperature;

[0147] Obtaining the overlapping time period of the abnormal current density time period and the abnormal electrolyte temperature time period, and recording it as the upper abnormal overlapping time period;

[0148] The upper abnormal time period of current density and the upper abnormal time period of electrolyte temperature are summed to obtain the upper abnormal characterization time period, and the upper abnormal characterization time period and the upper abnormal overlapping time period are calculated to obtain the upper abnormal total time period;

[0149] The ratio of the upper anomaly overlapping time period to the upper anomaly total time period is calculated to obtain the upper anomaly representation ratio, which is recorded as St;

[0150] Compare and process the abnormal time period under current density with the abnormal time period under electrolyte temperature;

[0151] Obtain the overlapping time period of the abnormal time period under current density and the abnormal time period under electrolyte temperature, and record it as the lower abnormal overlapping time period;

[0152] The abnormal time period under the current density is summed with the abnormal time period under the electrolyte temperature to obtain the lower abnormal characterization time period, and the lower abnormal characterization time period is difference-calculated with the lower abnormal overlapping time period to obtain the lower abnormal total time period;

[0153] The ratio of the lower anomaly overlapping time period to the lower anomaly total time period is calculated to obtain the lower anomaly representation ratio, which is recorded as Xt;

[0154] By formula The abnormal overlap characterization value SX corresponding to the abnormal current density and the abnormal electrolyte temperature during the electrolytic deposition process is calculated, wherein r is a preset proportional coefficient;

[0155] The process of obtaining the preset proportional coefficient is as follows:

[0156] There are m groups of historical data, each group of historical data includes the upper abnormal characterization ratio St, the lower abnormal characterization ratio Xt and the abnormal overlap characterization value SX corresponding to the abnormal current density and the abnormal electrolyte temperature during the electrolytic deposition process;

[0157] A linear model is used to fit m groups of historical data, and the prepared historical data is brought into the selected fitting model for fitting, and the mean of the fitting coefficients is obtained as the preset proportional coefficient.

[0158] See also Figure 3 , compare the abnormal overlap characterization value SX with the abnormal overlap characterization threshold sx;

[0159] If the abnormal overlap characterization value SX is greater than or equal to the abnormal overlap characterization threshold sx, it means that the abnormal current density in the electrolytic deposition process is associated with the abnormal electrolyte temperature, and a coordinated control signal is generated;

[0160] If the abnormal overlap characterization value SX is less than the abnormal overlap characterization threshold sx, it means that there is no correlation between the abnormal current density and the abnormal electrolyte temperature during the electrolysis process, and a non-cooperative control signal is generated.

[0161] It should be noted that: the coordinated control signal indicates that, during the electrolytic treatment process, the overlap rate of the abnormal time period corresponding to the unstable (abnormal) current density and the abnormal time period corresponding to the unstable (abnormal) electrolyte temperature is high. It can be deduced that there is a correlation between the unstable current density and the unstable electrolyte temperature. The non-coordinated control signal indicates that, during the electrolytic treatment process, the overlap rate of the abnormal time period corresponding to the unstable (abnormal) current density and the abnormal time period corresponding to the unstable (abnormal) electrolyte temperature is low. It can be deduced that there is no correlation between the unstable current density and the unstable electrolyte temperature.

[0162] Example 5

[0163] Since the change of electrolyte temperature will affect the current density, based on this, the electrolyte temperature and current density are coordinated and regulated;

[0164] See also Figure 4 , obtain all time units corresponding to the area where the current density curve is located between the upper boundary of the current density and the lower boundary of the current density, and record them as current density standard units;

[0165] Obtaining the electrolyte temperature corresponding to each current density standard unit, recorded as the first electrolyte test temperature;

[0166] Integrate the first electrolyte test temperatures corresponding to all current density standard units to obtain a first electrolyte test temperature group;

[0167] Obtain the maximum and minimum electrolyte temperatures within the first electrolyte test temperature group, record the maximum electrolyte temperature as C1max, and record the minimum electrolyte temperature as C1min;

[0168] That is, the obtained electrolyte temperature range [C1min, C1max] is the first standard temperature range of the electrolyte during the electrolysis process.

[0169] Obtain all time units corresponding to the area of ​​the electrolyte temperature curve between the electrolyte temperature upper limit and the electrolyte temperature lower limit, and record them as electrolyte temperature standard units;

[0170] Obtaining the electrolyte temperature corresponding to each electrolyte temperature standard unit, and recording it as the second electrolyte verification temperature;

[0171] Integrate the second electrolyte verification temperatures corresponding to all electrolyte temperature standard units to obtain a second electrolyte verification temperature group;

[0172] Obtain the maximum and minimum electrolyte temperatures within the second electrolyte test temperature group, record the maximum electrolyte temperature as C2max, and record the minimum electrolyte temperature as C2min;

[0173] That is, the electrolyte temperature interval [C2min, C2max] obtained is the second electrolyte temperature standard interval during the electrolytic deposition process;

[0174] The first standard temperature interval [C1min, C1max] of the electrolyte during the electrolysis process is overlapped with the second standard temperature interval [C2min, C2max] of the electrolyte during the electrolysis process to obtain the electrolyte overlap temperature interval, that is, the electrolyte temperature standard interval [Cmin, Cmax] during the electrolysis process.

[0175] In the process of obtaining the electrolyte temperature standard range, based on the fact that the change of electrolyte temperature will affect the current density, the current density standard unit corresponding to the qualified current density is first obtained, and the electrolyte temperature corresponding to the current density standard unit is integrated to obtain the first electrolyte temperature standard range (indicating that the current density in the electrolysis process within this temperature range is up to standard), and then reverse deduction is performed to obtain the electrolyte temperature standard unit corresponding to the qualified electrolyte temperature, and the electrolyte temperature corresponding to the electrolyte standard unit is integrated to obtain the second electrolyte temperature standard range (indicating that the electrolyte temperature in the electrolysis process within this temperature range is up to standard), that is, by overlapping the temperature range with current density as the object with the temperature range with electrolyte temperature as the object, that is, narrowing the temperature range to obtain the electrolyte temperature standard range in the electrolysis process, and achieving the required temperatures for the qualified electrolyte temperature and current density within this electrolyte temperature standard range.

[0176] Example 6

[0177] Then, the time unit in which the electrolyte temperature is within the electrolyte temperature standard interval [Cmin, Cmax] is marked as the approved time unit;

[0178] Obtain the current density corresponding to the approved time unit, and record it as the approved current density;

[0179] Integrate the rated current densities corresponding to all rated time units to obtain a rated current density group;

[0180] Obtain the maximum current density and the minimum current density in the rated current density group, record the maximum current density as Jmax, and record the minimum current density as Jmin;

[0181] That is, the current density interval obtained is the standard current density interval [Jmin, Jmax] during the electrowinning process;

[0182] Obtain the temperature range value within the standard range [Cmin, Cmax] of the electrolyte temperature during the electrolytic deposition process;

[0183] Among them, the temperature interval value is the difference between Cmax and Cmin;

[0184] Obtain the current density interval value within the current density standard interval [Jmin, Jmax] during the electrowinning process;

[0185] Among them, the current density range is the difference between Jmax and Jmin;

[0186] The temperature interval value and the current density interval value are calculated by ratio, and the temperature-electricity density correlation coefficient is obtained, which is recorded as jc;

[0187] In the actual regulation process of current density, when there is a deviation between the actual current density and the preset current density (not meeting the requirements), the deviation value of the current density is calculated with the temperature-electricity density correlation coefficient to obtain the temperature adjustment value of the electrolyte temperature. The electrolyte temperature is dynamically adjusted through an external temperature adjustment device to achieve online correction of the current density and electrolyte temperature during the electrolysis process to achieve a good electrolysis state.

[0188] The above is a detailed description of an embodiment of the present invention, but the content is only a preferred embodiment of the present invention and cannot be considered to limit the scope of implementation of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the patent coverage of the present invention.

Claims

1. A method for preparing electrolytic cobalt by circulating hydrochloric acid, characterized in that: The following steps are involved: Using cobalt concentrate, cobalt-copper alloy or crude cobalt salt as raw materials, leaching with sulfuric acid or hydrochloric acid to obtain a leachate containing cobalt ions; Purifying the leaching solution, extracting cobalt from the purified leaching solution using a P507 extractant to obtain a cobalt extract; The cobalt extract is stripped with hydrochloric acid to obtain a cobalt chloride solution, and the cobalt chloride solution is deoiled and mixed with an electrolytic solution to obtain an electrolytic pre-solution; Electrodeposition is performed on the pre-electrodeposition solution, and the current density is dynamically collected during the electrodeposition process. The amount of deposits in the electrodeposition is identified based on the current density data, and a current density verification signal is obtained according to the degree of deviation of the amount of deposits. Based on the current density calibration signal, the electroplating time is processed in segments, the reference current density corresponding to each unit time is intercepted to construct a current density curve, and the electrolyte temperature corresponding to each unit time is intercepted to construct an electrolyte temperature curve; The current density curve is compared with the electrolyte temperature curve to obtain the electrolyte temperature standard range based on the current density, and the electrolyte temperature and current density of the electrolytic deposition process are dynamically corrected according to the electrolyte temperature standard range; Cobalt ions are reduced to metallic cobalt at the cathode and oxidized to obtain chlorine at the anode. The obtained chlorine and the post-electrolysis liquid are introduced into the electrolysis liquid circulation tank, and the chlorine and the electrolysis liquid are separated by the gas-liquid separator. The chlorine gas is dried, and the dried chlorine gas is subjected to a synthesis reaction with hydrogen to obtain hydrogen chloride, which is absorbed by pure water to obtain hydrochloric acid, and the generated hydrochloric acid is returned to the P507 stripping process for reuse.

2. The method for preparing electrolytic cobalt by circulating hydrochloric acid according to claim 1, characterized in that: During the electrowinning process, the quality of the deposits on the electrodes is treated; That is, through the formula The actual mass m of the sediment is calculated; Where n is the electron transfer number of the deposited material, F is the Faraday constant, M is the molar mass of the deposited material, It is the total amount of charge passing through the electrode from time 0 to time t during the electrolysis process.

3. The method for preparing electrolytic cobalt by circulating hydrochloric acid according to claim 2, characterized in that: Comparing the sediment deviation amount with the sediment deviation amount threshold; If the deposit deviation is greater than or equal to the deposit deviation threshold, it means that the current density performance fluctuates during the electroplating process, and a current density verification signal is generated; If the deposit deviation is less than the deposit deviation threshold, it means that the current density is normal during the electroplating process, and a normal current density signal is generated.

4. The method for preparing electrolytic cobalt by circulating hydrochloric acid according to claim 3, characterized in that: Verify signal based on current density; The duration of the electrolytic process is divided into a number of time units, and the current density and electrolyte temperature corresponding to the middle moment of each time unit are obtained; Construct a two-dimensional coordinate system of current density-time unit, and construct a current density curve based on the current density corresponding to the middle moment of each time unit; Obtaining the abnormal area of ​​the upper current density and the abnormal area of ​​the lower current density; Constructing a two-dimensional coordinate system of electrolyte temperature-time unit, and constructing an electrolyte temperature curve with the electrolyte temperature corresponding to the middle moment of each time unit; Obtain the abnormal area on the electrolyte temperature and the abnormal area under the electrolyte temperature.

5. The method for preparing electrolytic cobalt by circulating hydrochloric acid according to claim 4, characterized in that: Obtaining an upper current density abnormal time period corresponding to the upper current density abnormal region and a lower current density abnormal time period corresponding to the upper current density abnormal region; Obtaining the abnormal time period of the electrolyte temperature corresponding to the abnormal area of ​​the electrolyte temperature and the abnormal time period of the electrolyte temperature corresponding to the abnormal area of ​​the electrolyte temperature; Obtaining the abnormal characterization ratio of the current density and the time in the abnormal area of ​​the electrolyte temperature; Obtain the lower abnormal characterization ratio of the current density and the abnormal region time at the electrolyte temperature; The upper abnormal characterization ratio and the lower abnormal characterization ratio are processed to obtain the abnormal overlap characterization value.

6. The method for preparing electrolytic cobalt by circulating hydrochloric acid according to claim 5, characterized in that: The abnormal overlap characterization value SX is compared with the abnormal overlap characterization threshold sx; If the abnormal overlap characterization value SX is greater than or equal to the abnormal overlap characterization threshold sx, it means that the abnormal current density in the electrolytic deposition process is associated with the abnormal electrolyte temperature, and a coordinated control signal is generated; If the abnormal overlap characterization value SX is less than the abnormal overlap characterization threshold sx, it means that there is no correlation between the abnormal current density and the abnormal electrolyte temperature during the electrolysis process, and a non-cooperative control signal is generated.

7. The method for preparing electrolytic cobalt by circulating hydrochloric acid according to claim 4, characterized in that: The process of obtaining the current density corresponding to the middle moment of the time unit is: Obtain the current corresponding to the middle moment of each time unit during the electrolytic deposition process, denoted as I; Obtain the electrolytic deposition area during the electrolytic deposition process, recorded as A; That is, through the formula The current density Ji corresponding to the middle moment of each time unit is calculated, where k is the electrode surface interference factor, i is the number of time units, i=1, 2, ..., m.

8. The method for preparing electrolytic cobalt by circulating hydrochloric acid according to claim 7, characterized in that: The process of obtaining the interference factor on the electrode surface is as follows: Identify the roughness and contamination degree of the electrode surface; The reference current density of the corresponding electrode without the influence of roughness and pollution is recorded as Jc; By formula The reference current density of the corresponding electrode under the influence of roughness and pollution is recorded as Jw, where g(R) is a function describing the influence of roughness on current density, and h(P) is a function describing the influence of pollution degree on current density; The electrode surface interference factor k is obtained by calculating the ratio of the reference current density Jw of the corresponding electrode when there is roughness and pollution influence and the reference current density Jc of the corresponding electrode when there is no roughness and pollution influence.

9. The method for preparing electrolytic cobalt by circulating hydrochloric acid according to claim 6, characterized in that: Based on co-regulatory signals; Obtain all time units corresponding to the area of ​​the current density curve between the upper boundary of the current density and the lower boundary of the current density, and record them as current density standard units; Obtain the maximum value C1max and the minimum value C1min of the electrolyte temperature corresponding to the current density standard unit, that is, obtain the first electrolyte temperature standard interval [C1min, C1max] during the electrolytic deposition process; Obtain all time units corresponding to the area of ​​the electrolyte temperature curve between the electrolyte temperature upper limit and the electrolyte temperature lower limit, and record them as electrolyte temperature standard units; Obtain the maximum electrolyte temperature C2max and the minimum electrolyte temperature C2min corresponding to the electrolyte temperature standard unit, that is, obtain the second electrolyte temperature standard interval [C2min, C2max] during the electrolytic deposition process; The first standard temperature interval [C1min, C1max] of the electrolyte during the electrolysis process is overlapped with the second standard temperature interval [C2min, C2max] of the electrolyte during the electrolysis process to obtain the electrolyte overlap temperature interval, that is, the electrolyte temperature standard interval [Cmin, Cmax] during the electrolysis process.

10. The method for preparing electrolytic cobalt by circulating hydrochloric acid according to claim 9, characterized in that: The time unit in which the electrolyte temperature is within the electrolyte temperature standard interval [Cmin, Cmax] is marked as the approved time unit; Obtain the maximum current density Jmax and the minimum current density Jmin corresponding to the approved time unit, that is, obtain the standard current density range [Jmin, Jmax] during the electrolytic deposition process; Obtain the temperature range value within the standard range [Cmin, Cmax] of the electrolyte temperature during the electrolytic deposition process; Obtain the current density interval value within the current density standard interval [Jmin, Jmax] during the electrowinning process; The temperature interval value and the current density interval value are ratio-calculated to obtain the temperature-electric density correlation coefficient. The current density deviation value and the temperature-electric density correlation coefficient are calculated to obtain the temperature adjustment value of the electrolyte temperature. The electrolyte temperature is dynamically adjusted through an external temperature adjustment device.

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