CN116577399A - A protection device for redox potentiometer in hydrometallurgy to prevent probe adhesion - Google Patents

Abstract

The invention relates to the technical field of probe protective sleeves, and specifically discloses a protection device for a redox potentiometer in wet smelting to prevent probe adhesion. There is a gap between them, the horizontal section of the probe protective cover body is a curved surface, the distance between the upper vertex of the curved surface and the lower bottom point is the long diameter, and the outermost end point of the curved surface is the short radius to the center point of the long diameter. Placed on the center point of the gap.

Description

A protection device for redox potentiometer in hydrometallurgy to prevent probe adhesion

technical field

The application relates to the technical field of probe protective sleeves, and specifically discloses a protective device for a redox potentiometer in hydrometallurgy that prevents probe adhesion.

Background technique

The hydrometallurgy zinc smelting process is a common zinc smelting process. Its main principle is to convert the zinc in the zinc-containing concentrate into water-soluble zinc sulfate through oxidation-reduction reactions, and then convert the zinc sulfate into pure zinc sulfate by electrolytic deposition. of zinc metal. With the grade of zinc concentrate, the content of zinc in the ore is also different, but in general, zinc concentrate will contain many impurity metals other than zinc, and these elements will also enter into the in solution. The existence of impurity metals will lead to insufficient purity of the zinc ingots produced by the electrolysis process. At the same time, impurity ions such as cadmium, cobalt, and germanium may also cause burn-in phenomenon, threatening production safety. Therefore, there is a purification process before the electrolysis process. Its main function is to add zinc powder and catalyst to the zinc sulfate solution, and use the replacement reaction to precipitate the impurity ions in the solution, so as to control the concentration of impurity ions at an acceptable level. within range.

The purification process is one of the important links in the production process of zinc hydrometallurgy. Its main goal is to remove impurities, and the production index of concern is the concentration of impurity ions in the solution. However, with the current detection technology, it is very difficult to accurately and efficiently detect the concentration of different ions in the solution. Most of the existing equipment can only detect the concentration of one ion, and it needs to go through a long time of processing. There are far more than one kind of impurity ions to be concerned about in the purification process, and it is unacceptable to install equipment for each impurity ion in each process, no matter in terms of cost or feasibility. Based on the above reasons, the production site usually chooses manual testing as the main method and machine testing as the auxiliary testing method. At the same time, in order to reduce the test intensity, the test of various ion concentrations will only be carried out at the entrance and exit of the purification process. There is a lag in manual testing methods, and it takes one and a half hours to two and a half hours from sampling to testing results. At the same time, there are relatively frequent fluctuations in the inlet ion concentration during the purification process. The above factors work together to cause the operator to obtain the ion concentration test data, the actual situation has already changed, and the obtained data cannot play a good role in guiding production.

The purification process is in a non-detection state to a certain extent, and the operator does not know the inlet situation, the degree of impurity removal reaction, and the concentration of impurity ions at the outlet. However, the purification process is so important that it will have a direct impact on the production of the electrolysis process. In order to ensure that the concentration of impurity ions at the outlet is qualified, the site can only ensure production safety by adding excessive zinc powder, resulting in a certain degree of waste of resources.

Oxidation Reduction Potential (ORP) is an indicator that reflects the macroscopic oxidation-reduction properties of the environment, and is often used to judge the pollution of water quality and soil. Compared with the traditional impurity ion concentration inspection device, the ORP meter has a series of advantages such as small equipment volume, low cost, and high detection frequency. Sun Bei and others studied the relationship between ORP and cobalt removal efficiency in the purification and cobalt removal process, and found that there is a negative correlation between the ORP value and the reaction rate of cobalt ions. That is to say, the more negative the ORP, the smaller the activation energy of cobalt ions, and the faster the reaction precipitation rate. Based on the above phenomena, Sun Bei and others established a mechanism model between the ORP value and the cobalt ion concentration at the reactor outlet, and achieved a good trend tracking effect. In order to further improve the prediction accuracy, Sun Bei and others combined the support vector machine (SVM) model with the mechanism model, and introduced more detection variables into the prediction model by using the powerful data mining and nonlinear fitting capabilities of SVM. The prediction deviation of the mechanism model was compensated by the SVM model, and a satisfactory prediction ability of cobalt ion concentration was obtained.

Further, Sun Bei and others proposed an intelligent optimization control method for cobalt removal process based on ORP. The author believes that for a specific process, the realization of the control goal depends on the design of the control strategy and the selection of the control method on the basis of understanding its nature and characteristics. Specifically, the removal process of cobalt is a process in which the concentration of cobalt ions gradually decreases. The dosage of zinc powder depends on its estimation of impurity removal efficiency. According to the mass balance, the reaction efficiency varies with the reaction rate. Therefore, zinc dust efficiency varies with time and varies between reactors. The total zinc dust consumption will vary if the reactors are assigned different cobalt removal task schedules. There is the most economical allocation of cobalt removal tasks, that is, there is an optimal cobalt ion concentration decline curve. Therefore, Sun Bei and others built an optimal control framework based on the two concepts of ZDUF (zinc powder utilization rate) and CRR (cobalt removal rate). Among them, CRR is realized by controlling the ORP range of different reactors. The author converts the optimal CRR of each reactor into the optimal ORP value range by integrating the process model, and then adjusts the addition of zinc powder to stabilize the ORP value in the corresponding range, so as to ensure that the concentration of cobalt ions at the outlet reaches the standard while reducing the The purpose of adding zinc powder.

The whole control strategy consists of process monitoring unit, zinc dust utilization factor (ZDUF) estimation unit, cobalt removal rate (CRR) optimization setting unit, oxidation reduction potential (ORP) setting unit and case-based reasoning (CBR) controller. The process monitoring unit judges the state of the current process. When the process is in a steady state, the economical optimization is carried out by assigning the appropriate CRR according to the ZDUF of the reactor. For automatic control, the CRR is converted to the ORP setpoint through an integrated model that also estimates the outlet cobalt ion concentration. Instance-based inference controllers handle undesired situations by providing a plausible understanding of the control variables when the process is in an abnormal state. Industrial tests have shown that the use of this control strategy can reduce the consumption of zinc powder while achieving the required cobalt removal performance. The stability of cobalt removal can also be improved by limiting the CRR of each reactor within a predetermined range;

To facilitate understanding, this case cites two documents:

[1]Sun B,Gui W H,Wu T B,et al.An integrated prediction model of cobalt ion concentration based on oxidation–reduction potential[J].Hydrometallurgy,2013,140:102-110.

[2]Sun B,Gui W H,Wang Y L,et al.Intelligent optimal setting control of a cobalt removal process[J].Journal of Process Control,2014,24(5):586-599.

For the first background scheme, aiming at the problem of predicting the cobalt ion concentration at the outlet of the reactor, the author deeply analyzed the reaction mechanism of the cobalt removal process. Using the principle of electrode reaction kinetics, the online detectable redox potential (ORP ). The author analyzed the relationship between ORP, mixed potential, and reaction rate, and found that the more negative the ORP, the faster the reaction rate in the cobalt ion displacement precipitation process, and determined that there was a negative correlation between ORP and the reaction rate. Furthermore, the author transformed the negative correlation between ORP and reaction rate into a linear relationship between ORP and mixing potential, and successfully introduced ORP into the mechanism model of cobalt removal reaction kinetics. The parameters of the dynamic model were identified by particle swarm optimization (PSO). The identified kinetic model has good tracking performance, but with limited accuracy. To this end, a data-driven compensation method based on support vector machines (SVM) was adopted and combined with a dynamic model to improve the adaptability of the model. The effectiveness of the integrated model is verified through industrial scale experiments.

For the second background scheme, aiming at the process index optimization problem of the cobalt removal process, the author uses two concepts of ZDUF (zinc powder utilization rate) and CRR (cobalt removal rate) to construct an optimal control framework. The control framework consists of a process monitoring unit, a ZDUF estimation unit, a CRR optimal setting unit, an oxidation-reduction potential (ORP) setting unit, and a case-based reasoning (CBR) controller. The process monitoring unit is used to judge the status of the current process. When the process is in a steady state, the optimal CRR is obtained according to the ZDUF of each reactor in each optimization step. The stability of the cobalt removal process was also achieved by limiting the CRR of each reactor within a predetermined range. By integrating the process model, the optimal CRR of each reactor is transformed into the control variable ORP value. In this way, a steady-state optimization is achieved. The comprehensive model also estimated the exit cobalt ion concentration of each reactor. When the cobalt removal process is in an abnormal state, process state adjustment is more significant than economic optimization. The CBR controller is thus triggered to provide reasonable setpoints for the control variables. Industrial trials carried out in a hydro-smelting zinc plant show that the application of the optimized control framework can improve the consumption of zinc dust and process stability;

The above background technology uses real-time detection of ORP to realize accurate prediction of cobalt ion concentration at the outlet of the reactor and intelligent optimal control of the purification and cobalt removal process, all of which have achieved satisfactory results. However, the above technologies are all based on accurate ORP detection. Only when the accurate and stable operation of the ORP meter is ensured can subsequent fine operations be performed. When there is a problem with the operation of the ORP meter and the detection accuracy drops, the fine operation based on the precise ORP value may cause unpredictable damage to the production process. In fact, the production environment of the purification process is relatively harsh, and the ORP meter will often be blocked during operation. The clogging phenomenon here refers to the accumulation of zinc powder solids and redox reaction precipitated solid products at the probe of the ORP meter, making the probe unable to fully contact the solution and unable to detect an accurate ORP value. This phenomenon will become more and more serious as time goes by. After the ORP meter probe is clogged, the clogging speed will become faster and faster. After a certain period of time, the ORP meter will not be able to perceive the redox environment of the solution. Change, lose detection function. Once the ORP meter fails to work, all intelligent prediction and control methods based on it will be out of the question. The stable and accurate operation of the ORP meter has become the weak link of the entire intelligent control framework. Therefore, in view of this, the inventor proposes a protection device for the redox potentiometer in wet smelting to prevent probe adhesion.

Contents of the invention

The design scheme of the probe protective cover body for the blockage problem of the oxidation-reduction potential detection device in the purification and cobalt removal process provided by the present invention solves the problem that the existing ORP meter cannot operate stably and accurately in the production environment of the purification process, and is effective The stable running time of the ORP meter is extended, and the maintenance frequency of the ORP meter is reduced.

In order to achieve the above object, the present invention provides the following basic solutions:

A protective device for a redox potentiometer in wet smelting to prevent probe adhesion, comprising a probe protective cover body symmetrically arranged in the chute of the purification process, gaps are left between the probe protective cover bodies, and the horizontal section of the probe protective cover body is It is a curved surface, the distance between the upper vertex of the curved surface and the lower bottom point is the long diameter, the outermost end point of the curved surface is the short radius to the center point of the long diameter, and the probe is placed on the center point of the gap;

The length range of the long diameter: 3cm-4cm; the length range of the short radius: 1.5cm-2.2cm, the length range of the gap: 0.9cm-1.1cm.

The method of using the probe protective cover body includes the following steps:

S01: Select the probe protective cover body with a diameter smaller than the chute, and install the probe protective cover body in the flow direction of the chute solution;

S02: Install the probe protective cover body and probe, and place the probe on the center point of the gap;

The principle and effect of this basic scheme are as follows:

1. Compared with the existing technology, due to the harsh production environment, the solid zinc in the solution and the deposits generated by the reaction will cause the probes of detection devices such as redox potentiometers to be blocked, affecting their accurate readings, which in turn will lead to accurate readings established in the detection devices. Intelligent control methods based on operation cannot be performed. The proposal of the probe protective cover body proposed by the present invention uses a simple and ingenious structure, which can accelerate the solution flow rate at the probe to the theoretical maximum value, and effectively suppress the clogging speed of the probe.

2. Compared with the prior art, compared with the automatic cleaning equipment, although the protective cover scheme proposed by the present invention does not fundamentally solve the problem of probe clogging, it can effectively suppress its clogging speed. At the same time, compared with the high cost of automatic cleaning equipment, the protective cover scheme proposed by the present invention has a series of advantages such as simple structure, low cost, easy deployment, and strong adaptability. In the case of insufficient budget, the protective cover solution proposed by the present invention will be an excellent choice to deal with the problem of probe blockage.

Further, the length of the long radius is selected as 3.25 cm, the length of the short radius is selected as 2 cm, and the length of the gap is selected as 1 cm.

Further, the probe protective cover body is an elliptical cylinder, the cross section of the elliptical cylinder is two ellipses, the length of the long radius of the ellipse is 3.25cm, the length of the short radius of the ellipse is 2cm, and the length of the gap between the ellipses is 1cm.

Further, the highest points on both sides of the probe protective cover body are higher than the highest points on both sides of the probe.

Further, the probe protective cover body is made of anti-corrosion material.

Further, both sides of the probe protective cover body are fixedly connected with brackets, and the brackets are fixedly connected to the inner wall of the chute.

Description of drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings that need to be used in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those skilled in the art, other drawings can also be obtained based on these drawings without any creative effort.

Fig. 1 shows a schematic structural diagram of a hydrometallurgy redox potentiometer protection device for preventing probe adhesion proposed in the embodiment of the present application;

Fig. 2 shows a simulation diagram of the flow velocity perpendicular to the flow field of the chute in a redox potentiometer protection device for hydro-smelting to prevent probe adhesion proposed in the embodiment of the present application;

Fig. 3 shows a detailed view of the solution flow direction of the probe protective cover body parallel to the flow field in a hydrometallurgy redox potentiometer protection device to prevent probe adhesion proposed in the embodiment of the present application;

Fig. 4 shows a simulation comparison diagram of the flow velocity perpendicular to the flow field and parallel to the flow field of the protective sleeve with the same structure in the anti-probe adhesion protection device for the redox potentiometer of the hydrometallurgy proposed in the embodiment of the present application;

Fig. 5 shows a simulation effect diagram when placed parallel to the flow field in a hydro-smelting redox potentiometer protection device to prevent probe adhesion proposed in the embodiment of the present application;

Fig. 6 shows a data diagram of the physical property parameters of the mixed solution during the test in a hydrometallurgy redox potentiometer protection device proposed in the embodiment of the present application to prevent probe adhesion;

Fig. 7 shows a data diagram of optimal dimensions in a hydrometallurgy redox potentiometer protection device proposed in the embodiment of the present application to prevent probe adhesion;

Fig. 8 shows a comparison of the improvement under the design of Fig. 7 in a hydrometallurgy redox potentiometer protection device for preventing probe adhesion proposed in the embodiment of the present application.

Detailed ways

In order to further explain the technical means and effects of the present invention to achieve the intended purpose of the invention, the specific implementation, structure, features and effects of the present invention will be described in detail below in conjunction with the accompanying drawings and preferred embodiments.

The reference signs in the accompanying drawings of the specification include:

The embodiment is shown in Fig. 1-Fig. 8 for example:

A protective device for a redox potentiometer in wet smelting to prevent probe adhesion, comprising a probe protective cover body symmetrically arranged in the chute of the purification process, gaps are left between the probe protective cover bodies, and the horizontal section of the probe protective cover body is It is a curved surface, the distance between the upper vertex of the curved surface and the lower bottom point is the long diameter, the outermost end point of the curved surface is the short radius to the center point of the long diameter, and the probe is placed on the center point of the gap;

The length range of the long diameter: 3cm-4cm; the length range of the short radius: 1.5cm-2.2cm, the length range of the gap: 0.9cm-1.1cm.

Taking the purification process of a zinc smelter as an example, the purification process mainly removes copper, cobalt, cadmium, germanium and other impurity ions in the solution by adding zinc powder and catalyst to the zinc sulfate solution. The solids in the solution are mainly zinc powder, mixed with solid impurities partially replaced by zinc powder particles.

Due to the different flow characteristics of different mixed solutions, we first determined the physical parameters of the zinc sulfate mixed solution in the purification process, as shown in Figure 6 below:

We use professional simulation software to simulate the chute and protective cover structure of the purification process. The parameters of the chute and the position of the protective sleeve in the chute are consistent with those on site. The schematic diagram of the geometric model is shown in Figure 1:

From Figures 2 to 5, it can be seen that in different protective sheath structures, the maximum solution flow rate is realized at the narrowest part of the protective sheath. This local acceleration phenomenon is called the Venturi effect, which is a special phenomenon produced when a liquid or gas flows through a pipe with a constricted section. The basic principle of the Venturi effect is that when a fluid passes through a constricted section, its flow velocity must increase due to the maintenance of the continuity equation. According to Bernoulli's law, the increase in flow velocity will be accompanied by a decrease in static pressure, that is, a decrease in pressure. In other words, as the cross-sectional area of the pipe decreases, the solution will form a negative pressure area at the constricted section, making the fluid move closer to the center of the constricted section, and an acceleration phenomenon will occur after the constricted section.

The continuity equation can be expressed as:

Among them, Q is the flow rate, A is the cross-sectional area, and v is the flow velocity. This equation states that in an incompressible fluid, the flow of fluid through different cross-sections must be equal, since continuity requires that the mass of the fluid remain constant throughout. According to the mass conservation equation, there is the formula:

A ₁ V ₁ =A ₂ V ₂ =Q

Among them, _A1 and _A2 represent different cross-sectional areas, _V1 and _V2 represent different solution flow rates, and Q represents the flow rate. According to the continuity equation, the flow through the wide section of the protective sleeve is the same as the flow through the narrow section. According to the law of conservation of mass, when the flow rate is the same, the flow velocity at the narrow section will be greater than that at the wide section. The flow velocity at the wide section is the same as the overall flow velocity of the chute, so that the flow velocity passing through the narrow section exceeds the overall flow velocity of the chute, achieving an acceleration effect.

The acceleration capability of the protective sleeve is related to the spacing and curvature of the components. The core is to guide as much solution as possible to flow through the protective sleeve to ensure its flow. At the same time, make the ratio of the wide section and the narrow section as large as possible to achieve the best acceleration effect. However, there is a limit to the acceleration effect of the protective sheath, and an unreasonable structure will increase the probability of vortex generation, resulting in an increase in the flow resistance of the solution flowing through the protective sheath. Since the diameter of the protective sleeve is much smaller than the diameter of the chute, there is a lot of space around the protection. When the flow resistance inside the protective sheath becomes larger due to the vortex, the solution will bypass the protective sheath and flow from both sides. This phenomenon is called the bypass phenomenon. The bypass phenomenon will cause the flow rate flowing from the protective sleeve to decrease, which in turn will result in a slower flow rate. In extreme cases, it will not only fail to accelerate but will also reduce the solution flow rate. The design of the structural parameters of the protective sleeve is very important to its practical application effect;

Through Figure 2 to Figure 5, we determine the size range of the section: the range of the long radius: 3cm-4cm; the range of the short radius: 1.5cm-2.2cm, the range of the gap: 0.9cm-1.1cm, which is the best favorable range:

After further simulation, the optimal size data was implemented, as shown in Figure 7 below, and the completed protective cover structure was applied to the purification production site. We first observed the blockage of the potentiometer probe when the protective case was not used for a period of time, after recording the data. At the same position, use the same type of potentiometer, install the protective cover device made by us, observe and record the effect after using the protective cover;

As shown in Figure 8, it can be seen that after applying the protective sleeve device designed by us, the average blockage time of the potentiometer probe is effectively extended to 8 days, and the maximum blockage time is extended to 7 days. That is to say, after applying the protective cover, the maintenance personnel changed from the initial 2-day maintenance to 7-day maintenance. Although the clogging problem was not fundamentally solved, the maintenance intensity was greatly reduced, and the potentiometer detection device was greatly enhanced. application value.

For the same probe, the optimal size data in Fig. 7 of the attached drawing of the specification is the optimal size data, and a method for using the probe protective cover body is also disclosed, including the following steps: S01: Select a probe protective cover body with a diameter smaller than the chute , install the probe protective cover body in the flow direction of the chute solution;

S02: Install the probe protective cover body and the probe, and place the probe on the center point of the gap; the highest points on both sides of the probe protective cover body are higher than the highest points on both sides of the probe. The body of the probe protective cover is made of anti-corrosion material. Both sides of the probe protective cover body are fixedly connected with brackets, and the brackets are fixedly connected on the inner wall of the chute.

The design scheme of the probe protective cover body for the blockage problem of the oxidation-reduction potential detection device in the purification and cobalt removal process provided by the present invention solves the problem that the existing ORP meter cannot operate stably and accurately in the production environment of the purification process, and is effective The stable running time of the ORP meter is extended, and the maintenance frequency of the ORP meter is reduced.

The above description is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as above with preferred embodiments, it is not intended to limit the present invention. Anyone skilled in the art , without departing from the scope of the technical solution of the present invention, when the technical content disclosed above can be used to make some changes or be modified into equivalent embodiments with equivalent changes, but as long as it does not depart from the technical solution of the present invention, the technical content of the present invention In essence, any brief modifications, equivalent changes and modifications made to the above embodiments still fall within the scope of the technical solution of the present invention.

Claims (7)

1. A wet smelting oxidation-reduction potentiometer protection device for preventing probe adhesion is characterized in that: the cleaning device comprises probe protective sleeve bodies symmetrically arranged in a chute in a cleaning procedure, gaps are reserved among the probe protective sleeve bodies, the cross section of the probe protective sleeve bodies in the vertical direction is a curved surface, the distance between the upper top point and the lower bottom point of the curved surface is a long diameter, the long radius is one half of the long diameter, the end point of the outermost side of the curved surface is a short radius from the center point of the long diameter, and the probe is arranged on the center point of the gaps;

wherein the length of the long diameter ranges: 6cm-8cm; length range of short radius: 1.5cm-2.2cm, the length range of the gap: 0.9cm-1.1cm.

2. The probe adhesion prevention hydrometallurgical oxidation reduction potentiometer protection device of claim 1, wherein the long radius is 3.25cm long, the short radius is 2cm long, and the gap is 1cm long.

3. The probe adhesion prevention hydrometallurgical oxidation reduction potentiometer protection device according to claim 2, wherein the probe protection sleeve body is an elliptical cylinder, the cross section of the elliptical cylinder is two ellipses, the length of the long radius of the ellipse is 3.25cm, the length of the short radius of the ellipse is 2cm, and the length of the gap of the ellipse is 1cm.

4. A method of using the probe protective sheath body according to claim 3, comprising the steps of:

s01: selecting a probe protective sleeve body with the diameter smaller than that of the chute, and installing the probe protective sleeve body in the flowing direction of the chute solution;

s02: and installing the probe protective sleeve body and the probe, wherein the probe is arranged on the center point of the gap.

5. The method of claim 4, wherein the highest points on both sides of the probe protective sleeve are higher than the highest points on both sides of the probe.

6. The method of claim 5, wherein the probe protective sheath body is made of anti-corrosion material.

7. The method of claim 4, wherein the probe protective sleeve body is fixedly connected with brackets on both sides, and the brackets are fixedly connected to the inner wall of the chute.