Aluminum electrolyte melt volatilization experiment device

Abstract

The utility model discloses an aluminum electrolyte melt volatilization experimental device, and solves the technical problem that the time for determining the material supplementing amount and the material supplementing type by sampling an industrial aluminum electrolysis cell every week in the prior art is relatively long. The experimental device comprises a heating furnace; the protective shell is located in the furnace chamber and comprises a body, a plug and a protective cover, the protective cover is erected on the body to close the second opening, a first operation hole is formed in the protective cover, and the plug is detachably installed in the first operation hole; the container is located in the body and provided with a third opening, and the cross section area of a containing cavity of the container is not changed in the height direction; and the measuring rod is used for extending into the aluminum electrolyte in the container through the first operation hole and the third opening to measure the liquid level height of the aluminum electrolyte so as to obtain the volatilization amount of the aluminum electrolyte. The experimental device provided by the utility model can obtain the volatilization rate of the aluminum electrolyte and the composition of the volatile matter so as to determine the material supplementing amount and the material supplementing type, the time is short, and the efficiency is high.

Description

Technical Field

[0001] The present application belongs to the technical field of aluminum smelting, and specifically relates to an aluminum electrolyte melt volatilization experimental device. Background Art

[0002] Aluminum electrolytic cells are usually produced by the Hall-Elut molten salt electrolysis method. The aluminum electrolyte melt in the aluminum electrolytic cell is the reaction medium for dissolving aluminum oxide and electrolytically reducing it to metallic aluminum during the aluminum electrolytic production process. It will contact the cathode and anode of the aluminum electrolytic cell and undergo electrochemical, physical and chemical coupling reactions in the tank. Therefore, the physical and chemical properties of the aluminum electrolyte melt determine the electrolysis temperature and affect the energy consumption of aluminum electrolysis, product quality and service life of the aluminum electrolytic cell.

[0003] Conventional aluminum electrolysis usually uses a sodium cryolite aluminum electrolyte system, including components such as LiF, KF and AlF3. Among them, LiF, KF, etc. in the aluminum electrolyte mainly come from K2O and Li2O impurities contained in the raw material alumina used for aluminum electrolysis, and of course there are also factors of artificial addition. Since the volatilization of aluminum electrolyte will affect the consumption, it is necessary to add feed to the aluminum electrolyte to improve the operating stability of aluminum electrolysis.

[0004] In the prior art, in the industrial production of aluminum electrolytic cells, aluminum electrolyte samples are taken for testing every week, and the type of feed to be added is determined based on the components of two adjacent samples. This method of determining the type of feed to be added by sampling the aluminum electrolyte in the electrolytic cell has a long cycle, resulting in poor operating stability of the aluminum electrolytic cell. Utility Model Content

[0005] In order to solve the technical problem that it takes a long time to determine the amount and type of feed by sampling and analyzing the aluminum electrolyte in the industrial aluminum electrolytic cell, the present application provides an aluminum electrolyte melt volatilization experimental device.

[0006] The present application provides an aluminum electrolyte melt volatilization experimental device, comprising:

[0007] A heating furnace having a furnace cavity with a first opening;

[0008] A protective shell is located in the furnace cavity, the protective shell comprises a body, a plug and a protective cover, the body is provided with a second opening, the protective cover is built on the body to close the second opening, the protective cover is provided with a first operating hole, and the plug is detachably mounted on the first operating hole;

[0009] a container for containing aluminum electrolyte, the container being located in the body and having a third opening communicating with the first operating hole;

[0010] A measuring rod is used to extend into the aluminum electrolyte in the container through the first operating hole and the third opening to measure the liquid level of the aluminum electrolyte to obtain the volatilization amount of the aluminum electrolyte.

[0011] In some embodiments, the container further comprises a cover for opening and closing the third opening, the cover is provided with a second operating hole, the first operating hole and the second operating hole are coaxially connected, and the measuring rod can be extended into the second operating hole.

[0012] In some embodiments, a sampling rod for taking aluminum electrolyte samples is further included, and the sampling rod can be extended into the first operation hole and the second operation hole.

[0013] In some embodiments, a feeding tube and a feeding funnel are connected, and the feeding tube can be extended into the first operating hole and the second operating hole for sampling.

[0014] In some embodiments, it further comprises:

[0015] a temperature sensor, used to detect the temperature of the aluminum electrolyte in the container;

[0016] A gas source and a gas pipe, one end of the gas pipe is connected to the gas source, and the other end passes through the protective cover and extends into the aluminum electrolyte in the container.

[0017] In some embodiments, a blower and a pressure gauge for detecting the pressure in the protective shell are further included, and the blower is connected to the protective shell via a pipeline passing through the protective cover.

[0018] In some embodiments, the protective cover is located outside the furnace cavity, and a cooling pipe is arranged around the outer edge. The experimental device also includes a chiller, and the outlet and the inlet of the chiller are respectively connected to the two ends of the cooling pipe.

[0019] In some embodiments, a collecting groove for collecting smoke deposits is provided on a side of the plug close to the container.

[0020] In some embodiments, the plug is conical and the collection tank is located at the small end of the plug.

[0021] In some embodiments, the cross-sectional area of ​​the accommodating cavity of the container remains unchanged along the height direction; a base for supporting the container is provided in the protective shell; the container is a crucible, and the heating furnace is a pit-type heating furnace.

[0022] According to an embodiment of the present application, an aluminum electrolyte melt volatilization experimental device is provided, including a heating furnace, a protective shell, a container and a measuring rod, the heating furnace is provided with a furnace chamber with a first opening; the protective shell is located in the furnace chamber, the protective shell includes a body, a plug and a protective cover, the body is provided with a second opening, the protective cover is mounted on the body to close the second opening, the protective cover is provided with a first operating hole, and the plug is detachably installed on the first operating hole; the container is used to accommodate the aluminum electrolyte, the container is located in the body and is provided with a third opening connected to the first operating hole; the measuring rod is used to extend into the aluminum electrolyte in the container through the first operating hole and the third opening to measure the liquid level of the aluminum electrolyte in the container to obtain the volatilization amount of the aluminum electrolyte.

[0023] Lift the protective cover, open the second opening of the protective shell, place the aluminum electrolyte in the container through the second opening and the third opening in turn, and then close the protective cover. The heating furnace heats the protective shell, container and aluminum electrolyte in the furnace chamber. It can be observed by naked eyes whether the aluminum electrolyte forms a liquid state. When the aluminum electrolyte forms a liquid state, open the plugging, and the end of the measuring rod extends into the liquid melt through the first operating hole and the third opening, and touches the bottom of the container. Then take out the measuring rod to know the liquid level of the melt. Plug the seal into the first operating hole and continue heating for a period of time. The smoke generated by the volatilization of the aluminum electrolyte at the electrolysis temperature will float out from the third opening and encounter the protective cover of the protective shell. Due to the low temperature of the protective cover, the smoke floating out of the container will gradually solidify and deposit on the bottom of the protective cover and the plugging when encountering low temperature. After the experiment, open the plugging again, extend the measuring rod through the first operating hole and the third opening into the liquid melt again, and touch the bottom of the container, and then take out the measuring rod to know the liquid level at this time.

[0024] The sediment at the bottom of the protective cover or under the plugging, that is, the volatile sample of the aluminum electrolyte, can be taken off to detect the composition of the volatiles. Since the measuring rod is inserted into the aluminum electrolyte melt twice, the height difference of the aluminum electrolyte liquid level at two moments can be determined, and then the volume of the containing cavity between the two height differences can be obtained to obtain the volatile amount of the aluminum electrolyte.

[0025] In summary, the aluminum electrolyte melt volatilization experimental device provided in the present application can sample volatiles, thereby realizing the detection of volatile components and determining the required feed type; by extending the measuring rod twice into the aluminum electrolyte liquid melt in the container, the height of the liquid level of the aluminum electrolyte during the experiment is obtained, and then the volume difference between the two liquid level height positions of the containing chamber is combined to obtain the volatilization amount of the aluminum electrolyte, thereby determining the amount of feed required for the aluminum electrolyte of this composition. The experimental device provided by the present application is used for multiple experiments, and aluminum electrolytes of different compositions are added to the container in each experiment, so that the volatilization amount of aluminum electrolytes of different compositions in the aluminum electrolytic cell and the volatilization characteristics such as volatile components can be obtained. Since the experimental device provided by the present application is carried out in the laboratory, experiments can be carried out at any time to determine the feed type and feed amount, providing data support for the production of industrial aluminum electrolytic cells, and sampling is flexible, time-saving and efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic structural diagram of an aluminum electrolyte melt volatilization experimental device in one or more embodiments of the present application is shown.

[0027] Figure 2 Shows Figure 1 Schematic diagram of the assembly structure of the heating furnace, shell, container and fan of the aluminum electrolyte melt volatilization experimental device.

[0028] Explanation of the accompanying drawings: 110-heating furnace, 111-first opening, 112-furnace chamber; 120-protective shell, 121-main body, 122-protective cover, 123-blocking, 124-first operating hole, 125-inner cavity; 130-container, 131-cover body, 132-second operating hole; 133-accommodating cavity 140-temperature sensor; 150-air pipe, 160-blower, 170-pressure gauge, 180-base; 190-aluminum electrolyte; 210-air source; 220-chiller. DETAILED DESCRIPTION

[0029] In order to make the technical personnel in the technical field to which the present application belongs to understand the present application more clearly, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present application.

[0030] The embodiment of the present application provides an aluminum electrolyte melt volatilization experimental device, which can detect the volatilization rate of aluminum electrolyte at the industrial aluminum electrolysis temperature, and can also sample and analyze the composition of volatiles in aluminum electrolysis, so as to determine the amount and type of feed, provide data support for the operation of industrial aluminum electrolysis, and improve the operation stability of the electrolytic cell.

[0031] See also Figure 1 as well as Figure 2 The aluminum electrolyte melt volatilization experimental device provided in the embodiment of the present application includes a heating furnace 110, a protective shell 120, a container 130 and a measuring rod.

[0032] The heating furnace 110 has a heating function and is provided with a furnace chamber 112 having a first opening 111, so that the protective shell 120 can be placed in the furnace chamber 112 through the first opening 111;

[0033] The protective shell 120 plays a protective role and can use a corundum furnace tube. The protective shell 120 is located in the furnace chamber 112 and includes a body 121, a plug 123 and a protective cover 122. The body 121 is provided with a second opening. The container 130 is placed in the inner cavity 125 of the body 121 through the second opening. The protective cover 122 is set on the body 121 to close the second opening. The protective cover 122 is located at the first opening 111, so the temperature here is lower than that of the container 130, which is convenient for operators to measure the depth of the aluminum electrolyte 190 melt in the container 130, and plays a protective role to prevent operators from being scalded. The protective cover 122 is provided with a first operating hole 124, and the plug 123 is detachably mounted on the first operating hole 124 so that the first operating hole 124 can be opened or closed. When the first operating hole 124 is opened, the measuring rod can be extended into the container 130 through the first operating hole 124 to detect the depth of the aluminum electrolyte 190 melt. When the plug 123 is inserted into the first operating hole 124, the first operating hole 124 is closed, and the volatiles of the aluminum electrolyte 190 melt can be deposited on the plug 123. The deposit on the plug 123 can be used as a sample to detect the chemical composition. In other embodiments, the aluminum electrolyte 190 deposit on the protective cover 122 can also be directly taken as a sample for detecting the chemical composition.

[0034] The container 130 is used to contain the aluminum electrolyte 190, and a crucible may be used. The container 130 is located in the inner cavity 125 of the body 121 and is provided with a third opening. The aluminum electrolyte 190 can be placed in the container 130 through the third opening, and the measuring rod can also measure the depth of the aluminum electrolyte 190 in the container 130 through the third opening. The container 130 is located in the body 121, and the heat generated by the heating furnace 110 is sequentially transferred to the body 121 of the protective shell 120, the container 130, and the aluminum electrolyte 190 through heat transfer.

[0035] The measuring rod is used to extend into the aluminum electrolyte 190 in the container 130 through the first operating hole 124 and the third opening. The measuring rod can be extended twice. The first time is when the aluminum electrolyte 190 has just formed a liquid state. At this time, it can be considered that the aluminum electrolyte 190 is about to volatilize the volatiles. The second time is the end point of the volatilization of the aluminum electrolyte 190, that is, the end point of the experiment. The measuring rod can be a metal rod, and its end contacts the bottom of the container 130. When it is taken out, a trace of the aluminum electrolyte 190 will be left on the metal rod, so that the depth of the aluminum electrolyte 190 can be measured. According to the depth of the aluminum electrolyte 190 twice and the volume difference between the two depth positions of the container, the volatilization amount of the aluminum electrolyte 190 can be known. In some embodiments, the measuring rod can have its own scale to directly read the depth. In other embodiments, the measuring rod itself has no scale, and the depth size is determined by a ruler.

[0036] The experimental process is as follows:

[0037] The protective cover 122 is opened, the second opening of the protective shell 120 is opened, and the aluminum electrolyte 190 is placed in the container 130 through the second opening and the third opening in sequence, and then the protective cover 122 is closed. The heating furnace 110 heats the protective shell 120, the container 130 and the aluminum electrolyte 190 in the furnace chamber 112. The temperature sensor 140 can be used to determine whether the aluminum electrolyte 190 is in a liquid state. When the aluminum electrolyte 190 is in a liquid state, the plug 123 is opened, and the end of the measuring rod is extended into the liquid melt through the first operating hole 124 and the third opening, and touches the bottom of the container 130. The measuring rod is then taken out to determine the liquid level of the melt. Insert the plug 123 into the first operating hole 124 and continue heating. Keep it at the electrolysis temperature for a period of time. The smoke generated by the volatilization of the aluminum electrolyte 190 at the electrolysis temperature will float out from the third opening and encounter the protective cover 122 of the protective shell 120. Since the middle position of the protective cover 122 is a certain distance away from the furnace wall of the heating furnace 110 and the temperature is relatively low, the smoke floating out of the container 130 will gradually solidify and deposit on the bottom of the protective cover 122 and the plug 123 when encountering the low temperature.

[0038] After the experiment, the plug 123 is opened again, and the measuring rod is inserted into the liquid melt through the first operating hole 124 and the third opening again, and touches the bottom of the container 130, and then the measuring rod is taken out, and the liquid level at this time can be known. According to the volume difference of the container 130 at two depth positions, the volatilization amount of the aluminum electrolyte 190 can be obtained. The sediment at the bottom of the protective cover 122, that is, the volatile sample of the aluminum electrolyte 190, can be taken down to detect the composition of the volatiles.

[0039] In some embodiments, the cross-sectional area of ​​the accommodating cavity 133 of the container 130 is constant along the height direction, that is, the cross-sectional area of ​​the accommodating cavity 133 is constant along the height direction. For example, the accommodating cavity 133 is a regular shape such as a cylinder, a cuboid or a cube, which can be directly multiplied by the depth difference measured by the measuring rod before and after the volatilization of the aluminum electrolyte 190, so as to calculate the volatilization amount of the aluminum electrolyte 190. In other embodiments, the container 130 can also be an irregular shape such as a frustum, and other means can be used, such as using two identical containers 130, namely a first container and a second container, adding water to the first container, the depth of the water is the same as the depth of the aluminum electrolyte measured for the first time, and then pouring the water in the first container into the second container, so that the depth of the water in the second container is the same as the depth of the aluminum electrolyte measured for the second time, that is, after volatilization. At this time, the volume of the remaining water in the first container is the same as the volume of the volatilized aluminum electrolyte 190, and the volume of the remaining water in the first container poured into the measuring cup is the volume of the volatilized aluminum electrolyte 190.

[0040] In some embodiments, the experimental device may also include a timer, which can obtain the time interval between two measurements of the depth of the aluminum electrolyte 190 by the measuring rod, and then the volatilization rate can be obtained by dividing the volatilization amount obtained above by the time interval. According to the volatilization rate, it can be determined what composition of the aluminum electrolyte 190 has the lowest volatilization rate at the electrolysis temperature of the aluminum electrolysis cell, thereby optimizing the composition of the aluminum electrolyte 190 and reducing costs.

[0041] In some embodiments, the calculation of the volatilization amount and the volatilization rate may be calculated manually or by using a controller, and this application does not impose any limitation thereto.

[0042] The container 130 further includes a cover 131 for opening and closing the third opening. The surface of the aluminum electrolyte 190 in the industrial aluminum electrolytic cell is covered with a heat-insulating layer. The setting of the cover 131 can simulate the heat-insulating layer on the surface of the aluminum electrolyte 190. The cover 131 is provided with a second operating hole 132. The first operating hole 124 can simulate the fire eye of the aluminum electrolytic cell. The first operating hole 124 and the second operating hole 132 are coaxially connected. The measuring rod can be extended into the second operating hole 132 to facilitate the detection of the depth of the aluminum electrolyte 190 in the container 130.

[0043] In some embodiments, the experimental device further includes a sampling rod for taking a sample of the aluminum electrolyte 190, and the sampling rod can be inserted into the first operation hole 124 and the second operation hole 132. The sampling rod can be a metal rod, and the plug 123 is opened when sampling the aluminum electrolyte 190. The metal rod passes through the first operation hole 124 and the second operation hole 132 in sequence, and then enters into the aluminum electrolyte 190 melt, and then passes through the second operation hole 132 and the first operation hole 124 in sequence and rises. The aluminum electrolyte 190 melt sample is adhered to the metal rod, and the component analysis can be performed after it is removed.

[0044] In some embodiments, the experimental device also includes a feeding tube and a feeding funnel connected to each other. The feeding tube can be inserted into the first operating hole 124 and the second operating hole 132 for sampling. Feeding can adjust the composition of the aluminum electrolyte 190. When feeding, the plug 123 is opened first, and the feeding tube passes through the first operating hole 124 and the second operating hole 132 in sequence and extends into the container 130. The feeding funnel is located outside the protective shell 120. The aluminum electrolyte 190 raw material is placed in the feeding funnel, and the raw material enters the container 130 along the feeding tube. In some embodiments, the feeding tube and the feeding funnel can be an integrated structure or a split structure. The feeding tube and the feeding funnel can both be made of steel.

[0045] In some embodiments, the experimental device further includes a temperature sensor 140, which is used to detect the temperature of the aluminum electrolyte 190 in the container 130, so that the temperature of the aluminum electrolyte 190 is the same as the temperature of the aluminum electrolyte in the industrial aluminum electrolytic cell, thereby improving the consistency of the experimental device with the industrial production temperature and ensuring the accuracy of the detection of the volatile amount and volatile components. The temperature sensor 140 can adopt existing technologies such as thermocouples.

[0046] In some embodiments, the experimental device further includes a gas source 210 and a gas pipe 150. One end of the gas pipe 150 is connected to the gas source 210, and the other end of the gas pipe 150 passes through the protective cover 122 and extends into the aluminum electrolyte 190 in the container 130. The gas source 210 is used for gas, and the gas pipe 150 is passed into the aluminum electrolyte 190. The gas can stir the aluminum electrolyte 190, simulating the stirring of the electrolyte melt by the anode gas in the aluminum electrolytic cell. The gas can be nitrogen.

[0047] In some embodiments, the experimental device further includes a fan 160 and a pressure gauge 170 for detecting the pressure in the protective shell 120. The fan 160 is connected to the protective shell 120 through a pipeline passing through the protective cover 122. The fan 160 can be set to form a negative pressure by exhausting air in the protective shell 120 to simulate the negative pressure state above the aluminum electrolytic cell. At this time, the protective shell 120 can also play a certain sealing role.

[0048] In some embodiments, the protective cover 122 is located outside the furnace chamber 112, so that the temperature of the protective cover 122 is lower than that of the body 121, which not only protects the protective cover 122, but also prevents the experimenter from being scalded during the operation process. The protective cover 122 can be a copper cover with good heat dissipation effect. In some embodiments, a cooling pipe is arranged around the outer edge of the protective cover 122, and the experimental device also includes a chiller 220, and the outlet and inlet of the chiller 220 are respectively connected to the two ends of the cooling pipe. The protective cover 122 is further cooled by the low-temperature cooling water provided by the chiller 220. In some embodiments, the chiller 220 includes a water tank and a refrigeration assembly. The water tank contains cooling water and sends the cooling water to the cooling pipe. The cooling water flows through the cooling pipe to absorb heat, the temperature rises, and then returns to the refrigeration assembly to absorb cold and cool down, and finally enters the water tank. The chiller 220 belongs to the prior art, and more content can be referred to the prior art disclosure.

[0049] In some embodiments, a collecting groove for collecting flue gas deposits is provided on one side of the plug 123 close to the container 130. Volatiles volatilized from the aluminum electrolyte 190 escape from the second operating hole 132 and are deposited in the collecting grooves of the protective cover 122 and the plug 123. The setting of the collecting groove facilitates the collection of volatile samples. In some embodiments, the plug 123 is a plug that is directly plugged into the first operating hole 124. In other embodiments, the plug 123 is threadedly installed in the first operating hole 124.

[0050] In some embodiments, the plugging 123 is conical, and the conical plugging 123 can be adjusted adaptively, and the plugging effect is good. The collecting tank is located at the small end of the plugging 123.

[0051] In some embodiments, a base 180 for supporting the container 130 is provided in the protective shell 120, so as to facilitate supporting the container 130; in some embodiments, a heating structure is provided in the heating furnace 110, which can be heated after being powered on. For example, the heating furnace 110 is a pit-type heating furnace 110, which has a good energy-saving effect and a high cost-effectiveness. The heating furnace 110 is a prior art, and more details can be referred to the prior art disclosure.

[0052] The simulation process of the experimental device provided in this application is further explained below in combination with the actual working conditions of an industrial aluminum electrolysis cell.

[0053] Example 1

[0054] The operating conditions of a 200kA aluminum reduction cell of an aluminum electrolytic enterprise were simulated, the volatilization of aluminum electrolyte 190 melt during its operation was measured, the effect of molecular ratio on the volatilization rate of aluminum electrolyte 190 melt was studied, and the composition of aluminum electrolyte 190 in the aluminum reduction cell was optimized and adjusted.

[0055] The carbon anode size of the 200kA aluminum electrolytic cell is 1500×660×570mm (length×width×height), and the flue gas flow rate is 5332m3 / h, the negative pressure above the aluminum electrolysis cell is -16.5Pa, and the anode current density is 0.82A / cm 2 The ratio of anode gas overflow to electrolyte melt surface area is 2.60 mL / (min·cm 2 ), the composition of aluminum electrolyte 190 is as follows: 43.52% NaF, 1.83% KF, 3.53% CaF2, 0.44% MgF2, 4.77% LiF, 1.74% Al2O3, the balance is AlF3, CR=2.38, the electrolysis temperature is 926°C, the current efficiency is 91.2%, and the aluminum fluoride unit consumption is 19kg / t-Al. Wherein CR represents the molar ratio of NaF to AlF3 in aluminum electrolyte 190.

[0056] Initial experiment: 190500g of aluminum electrolyte with 43.52% NaF, 1.83% KF, 3.53% CaF2, 0.44% MgF2, 4.77% LiF, 1.74% Al2O3, balance AlF3 and CR=2.38 was placed in a cross-sectional area of ​​113cm 2 The crucible is heated to 926°C at the temperature sensor 140 and then kept warm. 113*2.60=294mL / min of nitrogen is introduced through the air pipe 150. The frequency of the fan 160 is adjusted to keep the value of the pressure gauge 170 at -16.5Pa. When the sampling volume is high, the plug 123 is removed. The height and sample of the liquid electrolyte in the crucible are measured through the first operating hole 124 and the second operating hole 132. The composition change of the aluminum electrolyte 190 is obtained by analyzing the sample composition. The electrolyte mass is measured by height, and the volatilization amount of the aluminum electrolyte 190 per unit time can be obtained. According to the change result of the composition of the aluminum electrolyte 190, additives are added to stabilize the electrolyte composition. The volatiles of the electrolyte during the experiment are collected through the plug 123, and the volatiles are analyzed for phase.

[0057] In the 2nd to 5th experiments, the molecular ratio of aluminum electrolyte 190 was adjusted to 2.48, 2.58, 2.68 and 2.78 respectively, and the experimental temperature was increased by 7°C to 933°C, 940°C, 947°C and 953°C respectively. The other conditions were the same as the first experiment.

[0058] Table 1 Five volatilization experiments of Example 1

[0059]

[0060] According to the experimental results, the molecular ratio of aluminum electrolyte 190 has a great influence on the volatilization rate. Considering the electrolysis temperature, an electrolyte with a molecular ratio of 2.68 was selected for industrial testing. The electrolyte molecular ratio of the test cell was adjusted to 2.68, and additives were added to maintain other electrolyte components unchanged for industrial testing. The electrolysis temperature of the electrolytic cell was 947°C. After the test, the current efficiency was increased to 92.4%, and the unit consumption of aluminum fluoride was reduced to 15kg / t-Al.

[0061] Example 2

[0062] The operating conditions of a 400kA aluminum reduction cell of an aluminum electrolytic enterprise were simulated to measure the volatilization of aluminum electrolyte 190 melt during its operation, and the effect of potassium fluoride on the volatilization rate of aluminum electrolyte 190 melt was studied. The composition of aluminum electrolyte 190 in the aluminum reduction cell was optimized and adjusted.

[0063] The carbon anode size of the aluminum electrolytic cell is 1550×660×620mm (length×width×height), and the flue gas flow rate is 7537m 3 / h,m 3 / h, the negative pressure above the aluminum electrolysis cell is -21.7Pa, and the anode current density is 0.78A / cm 2 The ratio of anode gas overflow to electrolyte melt surface area is 2.47 mL / (min·cm 2 ), the components of aluminum electrolyte 190 are as follows in mass percentage: 47.62% NaF, 5.84% KF, 3.46% CaF2, 0.20% MgF2, 3.11% LiF, 1.72% Al2O3, and the balance is AlF3, CR=2.91, the electrolysis temperature is 944°C, the current efficiency is 90.9%, and the unit consumption of aluminum fluoride is 17.5kg / t-Al.

[0064] Initial experiment: 500 g of electrolyte with 47.62% NaF, 5.84% KF, 3.46% CaF2, 0.20% MgF2, 3.11% LiF, 1.72% Al2O3, balance AlF3, and CR=2.91 was placed in a cross-sectional area of ​​113 cm 2The crucible is heated to 944°C at the temperature sensor 140 and then kept warm. 113*2.47=135mL / min of nitrogen is introduced through the air pipe 150. The frequency of the fan 160 is adjusted to keep the value of the pressure gauge 170 at -21.7Pa. The sampling volume is high and the plug 123 is removed. The height and sample of the liquid electrolyte in the crucible are measured through the first operating hole 124 and the second operating hole 132. The electrolyte change is obtained by analyzing the sampling analysis results. The electrolyte mass is calculated by height, and the electrolyte volume per unit time can be obtained. Additives are added to stabilize the electrolyte composition according to the electrolyte composition change results. The volatiles of the electrolyte during the experiment are collected through the plug 123, and the volatiles are analyzed for phase.

[0065] In the 2nd to 5th experiments, the potassium fluoride concentration was adjusted to 5%, 4%, 3% and 2% respectively, and the experimental temperature was increased by 3°C to 947°C, 950°C, 953°C and 956°C respectively. The other conditions were the same as the first experiment.

[0066] Table 2 Volatilization experiment results

[0067]

[0068] According to the experimental results, the potassium fluoride concentration of aluminum electrolyte 190 has a great influence on the volatilization rate. Considering that the molecular ratio of the electrolytic cell is relatively high, the potassium fluoride and molecular ratio of the electrolyte of the electrolytic cell are optimized. After adjustment, the electrolyte composition is NaF45.42%, KF3%, CaF23.4%, MgF20.22%, LiF3.05%, Al2O31.72%, and the balance is AlF3. CR=2.65. Industrial tests were carried out, and the electrolysis temperature of the electrolytic cell was 952°C. After the test, the current efficiency was increased to 91.5%, and the unit consumption of aluminum fluoride was reduced to 16.2kg / t-Al.

[0069] The aluminum electrolyte 190 melt volatilization experimental device provided in the embodiment of the present application has at least the following advantages:

[0070] (1) The utility model can be used for the volatilization experiment of aluminum electrolyte 190 melt under high temperature conditions, and measure the volatilization amount and volatile composition of aluminum electrolyte 190, so as to determine the amount and type of feed, provide data support for industrial production, and improve the operation stability of aluminum electrolytic cells. Since the experimental device is used in the laboratory, the composition of the aluminum electrolyte can be adjusted multiple times in a short time without the need to cooperate with the production of industrial aluminum electrolytic cells, which is highly flexible, time-saving and efficient.

[0071] (2) The volatilization rate can be calculated based on the volatilization amount and the time interval. The composition of the aluminum electrolyte 190 can be optimized based on the volatilization rate to reduce the production cost.

[0072] (3) The experimental device provided in the present application can calculate the amount of gas introduced into the crucible based on the ratio of the anode gas overflow amount to the surface area of ​​the electrolyte melt in the aluminum electrolysis cell and the surface area of ​​the electrolyte melt in the container 130, and simulate the stirring and carrying of the electrolyte melt by the anode gas.

[0073] (4) The experimental device provided in this application can adjust the flow rate of the fan 160 according to the flue gas flow rate of the electrolytic cell to simulate the negative pressure state above the electrolytic cell.

[0074] (5) The experimental device provided in the present application can adjust the temperature of the heating furnace 110 according to the operating temperature and superheat of the aluminum electrolytic cell, so that the measured temperature and superheat of the aluminum electrolyte 190 melt are consistent with the temperature and superheat of the aluminum electrolyte 190 in the electrolytic cell.

[0075] (6) The experimental device provided in the present application can add materials, take samples, measure the depth of the aluminum electrolyte 190, and observe the state of the aluminum electrolyte 190 through the first operating hole 124 and the second operating hole 132. Through various experimental adjustments, the actual operating conditions of the electrolytic cell can be more realistically simulated, ensuring the accuracy of the high-temperature molten salt volatilization test.

[0076] In the present application, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0077] In the description of the present application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise" and "counterclockwise" indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0078] In this application, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0079] In addition, the descriptions of "first", "second", etc. in this application are only for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0080] Although the embodiments of the present application have been shown and described, those skilled in the art will appreciate that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present application, and that the scope of the present application is defined by the claims and their equivalents.

Claims

1. An aluminum electrolyte melt volatilization experimental device, characterized in that: include: A heating furnace having a furnace cavity with a first opening; A protective shell is located in the furnace cavity, the protective shell comprises a body, a plug and a protective cover, the body is provided with a second opening, the protective cover is built on the body to close the second opening, the protective cover is provided with a first operating hole, and the plug is detachably mounted on the first operating hole; a container for containing aluminum electrolyte, the container being located in the body and having a third opening communicating with the first operating hole; A measuring rod is used to extend into the aluminum electrolyte in the container through the first operating hole and the third opening to measure the liquid level of the aluminum electrolyte to obtain the volatilization amount of the aluminum electrolyte.

2. The aluminum electrolyte melt volatilization experimental device according to claim 1, characterized in that: The container further comprises a cover body for opening and closing the third opening, the cover body is provided with a second operating hole, the first operating hole and the second operating hole are coaxially connected, and the measuring rod can extend into the second operating hole.

3. The aluminum electrolyte melt volatilization experimental device according to claim 2, characterized in that: The device also includes a sampling rod for taking aluminum electrolyte samples, and the sampling rod can be extended into the first operation hole and the second operation hole.

4. The aluminum electrolyte melt volatilization experimental device according to claim 2, characterized in that: It also includes a connected feeding tube and a feeding funnel, and the feeding tube can be extended into the first operating hole and the second operating hole for sampling.

5. The aluminum electrolyte melt volatilization experimental device according to any one of claims 1 to 4, characterized in that: Also includes: a temperature sensor, used to detect the temperature of the aluminum electrolyte in the container; A gas source and a gas pipe, one end of the gas pipe is connected to the gas source, and the other end passes through the protective cover and extends into the aluminum electrolyte in the container.

6. The aluminum electrolyte melt volatilization experimental device according to any one of claims 1 to 4, characterized in that: It also includes a fan and a pressure gauge for detecting the pressure in the protective shell. The fan is connected to the protective shell through a pipeline passing through the protective cover.

7. The aluminum electrolyte melt volatilization experimental device according to any one of claims 1 to 4, characterized in that: The protective cover is located outside the furnace cavity, and a cooling pipe is arranged around the outer edge. The experimental device also includes a water chiller, and the outlet and the inlet of the water chiller are respectively connected to the two ends of the cooling pipe.

8. The aluminum electrolyte melt volatilization experimental device according to any one of claims 1 to 4, characterized in that: A collecting groove for collecting smoke deposits is provided on one side of the plug close to the container.

9. The aluminum electrolyte melt volatilization experimental device according to claim 8, characterized in that: The plug is conical, and the collecting groove is located at the small end of the plug.

10. The aluminum electrolyte melt volatilization experimental device according to any one of claims 1 to 4, characterized in that: The cross-sectional area of ​​the accommodating cavity of the container remains constant along the height direction; A base for supporting the container is arranged in the protective shell; the container is a crucible, and the heating furnace is a pit-type heating furnace.

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