A quality inspection system for aluminum hydroxide production

Abstract

The present invention relates to the field of product quality inspection, and in particular to a quality inspection system for aluminum hydroxide production. The technical problem to be solved by the present invention is that the existing quality inspection of aluminum hydroxide cannot reflect the quality of aluminum hydroxide in the production process in real time. The technical solution of the present invention is: a quality inspection system for aluminum hydroxide production, including an element detection unit, a production monitoring unit, a seed detection unit, a detection prediction unit, a feedback adjustment unit and a display parameter adjustment unit. The present invention detects the quality of aluminum hydroxide through an element detection unit and a seed detection unit, provides a judgment basis for the prediction of the quality of aluminum hydroxide, and at the same time takes the production environment parameters in the preparation process of aluminum hydroxide as the key part affecting the quality of aluminum hydroxide, and predicts the quality of aluminum hydroxide according to the changes in the production environment parameters, thereby improving the production efficiency and production benefits of aluminum hydroxide.

Description

Technical Field

[0001] The invention relates to the field of product quality detection, and in particular to a quality detection system for aluminum hydroxide production. Background Art

[0002] The Bayer process is a widely used industrial method for extracting aluminum oxide. It mainly involves mixing bauxite powder with sodium hydroxide solution under high temperature and pressure to dissolve the aluminum oxide to form a sodium tetrahydroxyaluminate solution, and then going through steps such as seed decomposition, precipitation, filtration and drying to ultimately obtain aluminum hydroxide with a higher purity.

[0003] In the actual production process, workers often judge the current quality of aluminum hydroxide by extracting some intermediate products in the production process. However, this judgment method cannot predict the quality changes of aluminum hydroxide. When quality problems arise in the production process, timely adjustments are made to deal with the problems, but they cannot be avoided in advance, resulting in the deterioration of the quality of aluminum hydroxide and causing serious losses. Summary of the invention

[0004] In order to overcome the shortcoming that the existing aluminum hydroxide quality detection cannot reflect the quality of aluminum hydroxide in the production process in real time, the present invention provides a quality detection system for aluminum hydroxide production that can detect and predict the quality of aluminum hydroxide in real time.

[0005] In order to solve the above technical problems, the present invention provides a quality detection system for aluminum hydroxide production, including an element detection unit, a preparation monitoring unit, a seed detection unit, a detection prediction unit, a feedback adjustment unit and a display parameter adjustment unit; an element detection unit, comprising an XRF instrument, wherein the XRF instrument is used to irradiate the bauxite powder sample or the aluminum hydroxide sample with X-rays, and to capture characteristic X-rays emitted by the bauxite powder sample or the aluminum hydroxide sample, and to detect the contents of different elements in the bauxite powder sample or the aluminum hydroxide sample through the characteristic X-rays; A preparation monitoring unit includes a temperature sensor, a pressure sensor, a flow sensor and an online pH meter, wherein the temperature sensor is used to monitor the preparation temperature during the bauxite powder leaching process and the aluminum hydroxide precipitation process, the pressure sensor is used to monitor the container pressure during the bauxite powder leaching process, the flow sensor is used to monitor the flow rate of the sodium hydroxide solution and the water flow rate during the bauxite powder leaching process and the aluminum hydroxide precipitation process, and the online pH meter is used to detect the solution acidity and alkalinity during the bauxite powder leaching process and the aluminum hydroxide precipitation process; A seed detection unit, including an XRD instrument, the XRD instrument is used to irradiate the aluminum hydroxide sample with emitted X-rays and capture the diffracted X-rays reflected by the aluminum hydroxide sample, and detect the lattice type of the aluminum hydroxide sample through the diffracted X-rays; A detection prediction unit is used to evaluate the quality of aluminum hydroxide samples and the overall preparation process of aluminum hydroxide, and predict the quality of aluminum hydroxide based on the preparation temperature, container pressure, solution pH, sodium hydroxide solution flow rate and water flow rate monitored by the preparation monitoring unit, as well as the element content detected by the element detection unit and the lattice type detected by the seed crystal detection unit; A feedback regulating unit is used to adjust the molar ratio of aluminum oxide to sodium hydroxide during the alkaline dissolution reaction of the bauxite powder by changing the flow rate of the sodium hydroxide solution based on the prediction result of the detection and prediction unit, and to adjust the pH of the solution during the bauxite powder leaching process and the aluminum hydroxide precipitation process by changing the flow rate of water, and to adjust the preparation temperature of the bauxite powder leaching process and the aluminum hydroxide precipitation process; The display and parameter adjustment unit includes a display and a host device, which is used to display all test results on the display and adjust the production environment parameters of aluminum hydroxide preparation by controlling the host device.

[0006] Preferably, the steps of detecting the contents of different elements in the bauxite powder sample or the aluminum hydroxide sample by characteristic X-rays are: S101: placing the prepared bauxite powder sample tablet or aluminum hydroxide sample tablet on a dedicated sample table, setting the voltage and current of the X-ray tube of the XRF instrument, and selecting the X-ray wavelength; S102: turning on the X-ray tube of the XRF instrument, the X-ray tube of the XRF instrument emits incident X-rays, the incident X-rays irradiate the bauxite powder sample tablet or the aluminum hydroxide sample tablet, so that the bauxite powder sample tablet or the aluminum hydroxide sample tablet emits characteristic X-rays; S103: The detector of the XRF instrument collects characteristic X-rays and generates an XRF spectrum. Based on the peak height in the XRF spectrum, data is compared with different standard samples to determine the type and content of elements in the sample.

[0007] Preferably, the element detection unit samples the bauxite powder used in each aluminum hydroxide preparation process and detects the element content, prepares the sodium hydroxide solution based on the content of each element, samples and evaporates the waste liquid generated by each aluminum hydroxide preparation, and detects the element content of the evaporated waste liquid sample to determine whether the waste liquid is involved in the next aluminum hydroxide preparation.

[0008] Preferably, the step of detecting the lattice type of the aluminum hydroxide sample by diffraction X-rays is: S201: placing the prepared aluminum hydroxide sample pressed tablet on a dedicated sample table, setting the voltage and current of the X-ray tube of the XRD instrument, and selecting the X-ray wavelength; S202: Calibrate using a standard silicon powder sample to ensure the accuracy of the instrument; S203: Turn on the X-ray tube of the XRD instrument, the X-ray tube of the XRD instrument emits incident X-rays, the incident X-rays irradiate the aluminum hydroxide sample pellet, and form diffracted X-rays; S204: The detector of the XRD instrument collects diffracted X-rays and generates an XRD spectrum. Based on the peak height in the XRD spectrum, data is compared with that of an aluminum hydroxide standard sample to determine the lattice type in the aluminum hydroxide sample.

[0009] Preferably, the step of the detection prediction unit performing quality assessment on the aluminum hydroxide sample is: S301: drying the aluminum hydroxide sample and placing it in an element detection unit and a seed crystal detection unit to perform element detection and seed crystal detection respectively; S302: The detection results of the element detection unit and the seed crystal detection unit are input into the detection prediction unit to perform quality evaluation calculation of the aluminum hydroxide sample. The quality evaluation calculation formula of the aluminum hydroxide sample is:

[0010] in, is the mass evaluation value of the aluminum hydroxide sample, 2.89 is the relative molecular mass ratio between aluminum hydroxide and aluminum when the molecular quantity is the same, is the aluminum content in the aluminum hydroxide sample, is the ratio of the desired aluminum hydroxide lattice type to the lattice type of the aluminum hydroxide sample.

[0011] Preferably, the steps of the detection prediction unit for overall evaluation of the preparation process of aluminum hydroxide are: Before each preparation of aluminum hydroxide, the detection prediction unit will record the total weight of the bauxite powder. After each detection by the element detection unit and the seed detection unit, the aluminum element content result and the required aluminum hydroxide lattice type ratio result will be entered into the detection prediction unit, and the detection prediction unit will also record the total weight of aluminum hydroxide, so as to evaluate and calculate the preparation process of aluminum hydroxide. The preparation process evaluation calculation formula is:

[0012] in, is the evaluation value of the aluminum hydroxide preparation process, is the aluminum content in the aluminum hydroxide sample, is the ratio of the desired aluminum hydroxide lattice type to the lattice type of the aluminum hydroxide sample, is the aluminum content in bauxite powder, is the total mass of bauxite powder, is the total mass of aluminum hydroxide prepared.

[0013] Preferably, the detection prediction unit predicts the quality of aluminum hydroxide based on the preparation temperature, container pressure, solution pH, sodium hydroxide solution flow rate and water flow rate monitored by the preparation monitoring unit, the element content detected by the element detection unit and the lattice type detected by the seed detection unit, and the steps of: S401: During the preparation process of each batch of aluminum hydroxide, the detection prediction unit reads the preparation temperature, container pressure, sodium hydroxide solution flow rate, solution pH, and water flow rate collected by the preparation monitoring unit once every period of time, and saves these collected data as a two-dimensional first data group, the first dimension data of the first data group are different production environment parameters at the same time, the second dimension data of the first data group are the same production environment parameters at different times, and the second dimension data of the first data group are averaged to obtain a one-dimensional second data group; S402: The relationship between the predicted value of aluminum hydroxide mass and the second data set is:

[0014] in, is the predicted value of aluminum hydroxide quality, 3 is the number of aluminum hydroxide preparation processes, the aluminum hydroxide preparation process includes bauxite powder leaching process and aluminum hydroxide precipitation process, the aluminum hydroxide precipitation process is divided into aluminum hydroxide crystallization process and aluminum hydroxide crystal growth process, The first The number of production environment parameters for each process, The first In the process The base number of the influence of production environment parameters on the quality of aluminum hydroxide, The first In the process Production environment parameters; S403: Based on the relationship between the quality prediction value of aluminum hydroxide and the second data group, the quality assessment value of aluminum hydroxide is used as the quality prediction value of aluminum hydroxide, and the production environment parameters of the second data group are substituted into the relationship to perform function fitting, so as to obtain a finished product prediction and assessment formula that conforms to the aluminum hydroxide preparation process, and the preparation temperature, container pressure, sodium hydroxide solution flow rate, water flow rate and solution pH collected in real time by the preparation monitoring unit are substituted into the finished product prediction and assessment formula of the aluminum hydroxide preparation process, and the quality prediction value of aluminum hydroxide is obtained by calculation, thereby predicting the quality of aluminum hydroxide.

[0015] Preferably, the feedback regulating unit adjusts the molar ratio of aluminum oxide to sodium hydroxide during the alkaline dissolution reaction of the bauxite powder by changing the flow rate of the sodium hydroxide solution, and jointly adjusts the pH of the solution during the bauxite powder leaching process and the aluminum hydroxide precipitation process by changing the water flow rate, and adjusts the preparation temperature of the bauxite powder leaching process and the aluminum hydroxide precipitation process in the following steps: Based on the relationship between the predicted value of aluminum hydroxide mass and the second data group, the preparation temperature, container pressure, sodium hydroxide solution flow rate, water flow rate and solution pH in the relationship are derived to predict the influence of the changing trend of the preparation temperature, container pressure, sodium hydroxide solution flow rate, water flow rate and solution pH on the quality of aluminum hydroxide. Based on the influence of the changing trend on the quality of aluminum hydroxide, the sodium hydroxide solution flow rate is changed to adjust the molar ratio of aluminum oxide to sodium hydroxide during the alkaline dissolution reaction of the bauxite powder, and the water flow rate is changed to adjust the solution pH of the bauxite powder leaching process and the aluminum hydroxide precipitation process together with the sodium hydroxide solution. At the same time, the preparation temperature of the bauxite powder leaching process and the aluminum hydroxide precipitation process is adjusted, so that the relationship between the predicted value of aluminum hydroxide mass and the second data group is derived with respect to the preparation temperature, container pressure, sodium hydroxide solution flow rate, water flow rate and solution pH, and then the data of the second data group is substituted into the derived relationship. The result tends to 0, and the quality prediction of aluminum hydroxide will reach the best quality at this time.

[0016] Preferably, data from the element detection unit, preparation monitoring unit, seed detection unit, detection prediction unit and feedback adjustment unit are transmitted to the display parameter adjustment unit via a network, and the display parameter adjustment unit can visualize the data.

[0017] Preferably, the display parameter adjustment unit modifies the base of the degree of influence of preparation temperature, container pressure, solution pH, sodium hydroxide solution flow rate and water flow rate on the quality of aluminum hydroxide in the finished product prediction evaluation formula of the aluminum hydroxide preparation process by manual adjustment.

[0018] The beneficial effects of the present invention are: 1. The quality of aluminum hydroxide is detected by the element detection unit and the seed crystal detection unit to provide a judgment basis for the prediction of the quality of aluminum hydroxide. At the same time, the production environment parameters in the preparation process of aluminum hydroxide are the key part affecting the quality of aluminum hydroxide. The quality of aluminum hydroxide is predicted according to the changes in the production environment parameters, thereby improving the production efficiency and production benefits of aluminum hydroxide; 2. The environment during the preparation of aluminum hydroxide is detected by the production monitoring unit, so that the feedback adjustment unit adjusts the production environment parameters based on the prediction results of the detection prediction unit to prevent production anomalies during the preparation of aluminum hydroxide and avoid loss of benefits caused by abnormal production environment parameters. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a system architecture diagram of the present invention; Figure 2 The present invention is a flow chart of the quality assessment of aluminum hydroxide by the detection and prediction unit; Figure 3 The present invention is a flowchart for executing the overall evaluation of the preparation process of aluminum hydroxide by the detection prediction unit of the present invention. DETAILED DESCRIPTION

[0020] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0021] like Figure 1-Figure 3 As shown, in order to solve the problem that the existing aluminum hydroxide quality detection cannot reflect the quality of aluminum hydroxide in the production process in real time, the present invention provides a quality detection system for aluminum hydroxide production, including an element detection unit, a preparation monitoring unit, a seed detection unit, a detection prediction unit, a feedback adjustment unit and a display parameter adjustment unit; an element detection unit, comprising an XRF instrument, wherein the XRF instrument is used to irradiate the bauxite powder sample or the aluminum hydroxide sample with X-rays, and to capture characteristic X-rays emitted by the bauxite powder sample or the aluminum hydroxide sample, and to detect the contents of different elements in the bauxite powder sample or the aluminum hydroxide sample through the characteristic X-rays; A preparation monitoring unit includes a temperature sensor, a pressure sensor, a flow sensor and an online pH meter. The temperature sensor is used to monitor the preparation temperature during the bauxite powder leaching process and the aluminum hydroxide precipitation process. The pressure sensor is used to monitor the container pressure during the bauxite powder leaching process. By adjusting the container pressure, the speed and concentration of aluminum hydroxide precipitation are controlled. The flow sensor is used to monitor the flow rate of sodium hydroxide solution and the flow rate of water during the bauxite powder leaching process and the aluminum hydroxide precipitation process. The online pH meter is used to detect the solution acidity and alkalinity during the bauxite powder leaching process and the aluminum hydroxide precipitation process. A seed detection unit, including an XRD instrument, the XRD instrument is used to irradiate the aluminum hydroxide sample with emitted X-rays and capture the diffracted X-rays reflected by the aluminum hydroxide sample, and detect the lattice type of the aluminum hydroxide sample through the diffracted X-rays; A detection prediction unit is used to evaluate the quality of aluminum hydroxide samples and the overall preparation process of aluminum hydroxide, and predict the quality of aluminum hydroxide based on the preparation temperature, container pressure, solution pH, sodium hydroxide solution flow rate and water flow rate monitored by the preparation monitoring unit, as well as the element content detected by the element detection unit and the lattice type detected by the seed crystal detection unit; A feedback regulating unit is used to adjust the molar ratio of aluminum oxide to sodium hydroxide during the alkaline dissolution reaction of the bauxite powder by changing the flow rate of the sodium hydroxide solution based on the prediction result of the detection and prediction unit, and to adjust the pH of the solution during the bauxite powder leaching process and the aluminum hydroxide precipitation process by changing the flow rate of water, and to adjust the preparation temperature of the bauxite powder leaching process and the aluminum hydroxide precipitation process; The display and parameter adjustment unit includes a display and a host device, which is used to display all test results on the display and adjust the production environment parameters of aluminum hydroxide preparation by controlling the host device.

[0022] In this embodiment, the main active ingredient for preparing aluminum hydroxide from bauxite powder is aluminum oxide. The bauxite is crushed by a crusher, ground by a ball mill and sieved by a screening machine to obtain bauxite powder with a particle size less than 200 mesh (diameter 75 microns). A portion of the bauxite powder is taken out as the first sample, the first sample is made into a tablet, and placed in an element detection unit for preliminary detection.

[0023] Specifically, the steps of detecting the contents of different elements in a bauxite powder sample or an aluminum hydroxide sample by characteristic X-rays are as follows: S101: placing the prepared bauxite powder sample tablet or aluminum hydroxide sample tablet on a dedicated sample table, setting the voltage and current of the X-ray tube of the XRF instrument, and selecting a suitable X-ray wavelength; S102: Turn on the X-ray tube of the XRF instrument, and the X-ray tube of the XRF instrument emits incident X-rays, which are irradiated on the bauxite powder sample tablet or the aluminum hydroxide sample tablet, so that the inner electrons of the sample atoms and sample ions undergo electron transitions after absorbing the energy of the incident X-rays, and the outer electrons fill the inner electron vacancies at this time, and release energy in the form of characteristic X-rays, so that the bauxite powder sample tablet or the aluminum hydroxide sample tablet emits characteristic X-rays; S103: The detector of the XRF instrument collects characteristic X-rays and generates an XRF spectrum. Based on the peak height in the XRF spectrum, data is compared with different standard samples to determine the type and content of elements in the sample.

[0024] Specifically, the abscissa of the XRF spectrum is the energy of the characteristic X-rays. Different elements have different corresponding abscissa positions in the XRF spectrum. The ordinate is the intensity of the X-rays. The higher the element content, the greater the peak height of the curve in the XRF spectrum.

[0025] In this embodiment, the aluminum content and the content of other elements in the bauxite powder can be determined based on the element detection unit, thereby determining the alumina content of the bauxite powder, and further determining the amount of sodium hydroxide added in the alkaline dissolution reaction. The bauxite powder, sodium hydroxide solution and water are added to the digestion tank. The molar ratio of the alumina in the bauxite powder to the sodium hydroxide in the sodium hydroxide solution is in the range of 1:1.5 to 1:2.5. If the alumina content in the bauxite powder is too high, the effective reaction area of ​​the bauxite powder will be too large, and the amount of sodium hydroxide required to be added will also be too small. The chemical equation for the alkaline dissolution reaction of sodium hydroxide and alumina is:

[0026] In the alkaline dissolution reaction, the density of the mixture should be maintained at 1.4 to 1.6 grams per cubic centimeter, the temperature should be maintained at 140 to 200 degrees Celsius, and the pressure in the digester should be maintained at 0.5 to 1.5 MPa. A high density of the mixture indicates that the mixture contains more sodium hydroxide and alumina. More sodium hydroxide and alumina will speed up the reaction process, thereby releasing more heat. The increase in temperature will further accelerate the rate of the alkaline dissolution reaction. The higher the pressure in the digester, the higher the solubility of alumina in the alkaline dissolution reaction, further accelerating the rate of the alkaline dissolution reaction.

[0027] During the alkaline dissolution of alumina, impurity silicon dioxide reacts with sodium hydroxide to generate water-soluble impurity sodium silicate. Sodium silicate is easily soluble in water, and the sodium silicate solution is viscous, which slows down the reaction rate of sodium hydroxide and alumina.

[0028] After the alkaline dissolution reaction, the mixed solution is filtered, and the impurities in the mixed solution are retained above the filter, thereby being separated from the sodium tetrahydroxyaluminate solution. The sodium tetrahydroxyaluminate solution is cooled to 50 to 60 degrees Celsius, so that the aluminum hydroxide in the sodium tetrahydroxyaluminate solution is in a supersaturated state, and aluminum hydroxide seeds are added to the sodium tetrahydroxyaluminate solution. Sodium ions and hydroxides crystallize on the surface of the aluminum hydroxide seeds. The sodium tetrahydroxyaluminate solution is then heated to 80 to 90 degrees Celsius and continuously stirred to cause the sodium ions and hydroxides to be disturbed by the outside world and further crystallize on the surface of the aluminum hydroxide seeds. The aluminum hydroxide grains gradually grow. The crystallization process is affected by the aluminum content of the bauxite, and the crystallization time ranges from 2 hours to 1 day.

[0029] The aluminum hydroxide obtained by crystallization is washed with hot water 2 to 4 times to remove impurities, and then crushed, ground and dried to obtain the finished aluminum hydroxide product. Since the remaining solution of the crystallization still contains a large amount of sodium hydroxide, the pH value of the remaining solution of the crystallization is adjusted by adding water or sodium hydroxide solution, and then the alkaline dissolution reaction of the next batch of bauxite is continued.

[0030] During the alkaline dissolution of alumina, impurity silicon dioxide reacts with sodium hydroxide to form impurity sodium silicate. Sodium silicate is easily soluble in water, and the sodium silicate solution is viscous, which slows down the reaction rate of sodium hydroxide and alumina. Therefore, it is necessary to take part of the crystallized solution for evaporation and tableting. The element detection unit detects the element content to determine the sodium silicate content of the solution after the reaction.

[0031] The element detection unit samples the bauxite powder used in each aluminum hydroxide preparation process and detects the element content, prepares the sodium hydroxide solution based on the content of each element, samples and evaporates the waste liquid generated by each aluminum hydroxide preparation, and detects the element content of the evaporated waste liquid sample to determine whether the waste liquid will be used in the next aluminum hydroxide preparation, thereby avoiding the waste of sodium hydroxide and aluminum hydroxide in the waste liquid.

[0032] In this embodiment, if the silicon content in the waste liquid after evaporation exceeds 2.5% and the aluminum content is less than 40%, it means that the adjustment cost for continued utilization of the waste liquid is too high, the preparation efficiency of aluminum hydroxide cannot guarantee the quality of the produced aluminum hydroxide, and the waste liquid no longer enters the reaction cycle process.

[0033] In this embodiment, the finished aluminum hydroxide product needs to be tested for quality and the production efficiency needs to be calculated. Therefore, the finished aluminum hydroxide product is sampled as a second sample and a sample tablet is made. The aluminum hydroxide content of the second sample is analyzed using an element detection unit.

[0034] Specifically, the steps of detecting the lattice type of the aluminum hydroxide sample by diffraction X-rays are: S201: placing the prepared aluminum hydroxide sample pressed tablet on a dedicated sample table, setting the voltage and current of the X-ray tube of the XRD instrument, and selecting a suitable X-ray wavelength; S202: Calibrate using a standard silicon powder sample to ensure the accuracy of the instrument; S203: turning on the X-ray tube of the XRD instrument, the X-ray tube of the XRD instrument emits incident X-rays, the incident X-rays are irradiated on the aluminum hydroxide sample pressed tablet, the particle distance between the aluminum hydroxide sample atoms or sample ions is close to the wavelength of the incident X-rays, so that the incident X-rays will be diffracted when irradiated on the aluminum hydroxide sample pressed tablet, and multiple incident X-rays after diffraction are superimposed on each other to form diffracted X-rays; S204: The detector of the XRD instrument collects diffracted X-rays and generates an XRD spectrum. Based on the peak height in the XRD spectrum, data is compared with that of an aluminum hydroxide standard sample to determine the lattice type in the aluminum hydroxide sample.

[0035] Specifically, the abscissa of the XRD spectrum is the angle between the incident X-ray and the diffracted X-ray, which is the diffraction angle, and the ordinate is the intensity of the diffracted X-ray. Different crystal structures have different interplanar spacings, and therefore diffraction peaks are generated at different diffraction angle positions.

[0036] In this embodiment, the lattice type of aluminum hydroxide is analyzed by a seed detection unit to obtain the ratio of the required aluminum hydroxide lattice type to the produced aluminum hydroxide lattice type, so as to determine whether the lattice structure of the produced aluminum hydroxide meets the requirements.

[0037] Specifically, the steps of the detection prediction unit for evaluating the quality of the aluminum hydroxide sample are as follows: S301: drying the aluminum hydroxide sample and placing it in an element detection unit and a seed crystal detection unit to perform element detection and seed crystal detection respectively; S302: The detection results of the element detection unit and the seed crystal detection unit are input into the detection prediction unit to perform quality evaluation calculation of the aluminum hydroxide sample. The quality evaluation calculation formula of the aluminum hydroxide sample is:

[0038] in, is the mass evaluation value of the aluminum hydroxide sample, 2.89 is the relative molecular mass ratio between aluminum hydroxide and aluminum when the molecular quantity is the same, is the aluminum content in the aluminum hydroxide sample, is the ratio of the desired aluminum hydroxide lattice type to the lattice type of the aluminum hydroxide sample.

[0039] Specifically, the steps of the detection prediction unit for overall evaluation of the preparation process of aluminum hydroxide are: Before each preparation of aluminum hydroxide, the detection prediction unit will record the total weight of the bauxite powder. After each detection by the element detection unit and the seed detection unit, the aluminum element content result and the required aluminum hydroxide lattice type ratio result will be entered into the detection prediction unit, and the detection prediction unit will also record the total weight of aluminum hydroxide, so as to evaluate and calculate the preparation process of aluminum hydroxide. The preparation process evaluation calculation formula is:

[0040] in, is the evaluation value of the aluminum hydroxide preparation process, is the aluminum content in the aluminum hydroxide sample, is the ratio of the desired aluminum hydroxide lattice type to the lattice type of the aluminum hydroxide sample, is the aluminum content in bauxite powder, is the total mass of bauxite powder, is the total mass of aluminum hydroxide prepared.

[0041] Specifically, the detection prediction unit predicts the quality of aluminum hydroxide based on the preparation temperature, container pressure, solution pH, sodium hydroxide solution flow rate and water flow rate monitored by the preparation monitoring unit, the element content detected by the element detection unit and the lattice type detected by the seed detection unit. The steps are: S401: During the preparation process of each batch of aluminum hydroxide, the detection prediction unit reads the preparation temperature, container pressure, sodium hydroxide solution flow rate, solution pH, and water flow rate collected by the preparation monitoring unit once every period of time, and saves these collected data as a two-dimensional first data group, the first dimension data of the first data group are different production environment parameters at the same time, the second dimension data of the first data group are the same production environment parameters at different times, and the second dimension data of the first data group are averaged to obtain a one-dimensional second data group; S402: The relationship between the predicted value of aluminum hydroxide mass and the second data set is:

[0042] in, is the predicted value of aluminum hydroxide quality, 3 is the number of aluminum hydroxide preparation processes, the aluminum hydroxide preparation process includes bauxite powder leaching process and aluminum hydroxide precipitation process, the aluminum hydroxide precipitation process is divided into aluminum hydroxide crystallization process and aluminum hydroxide crystal growth process, The first The number of production environment parameters for each process, The first In the process The base number of the influence of production environment parameters on the quality of aluminum hydroxide, The first In the process Production environment parameters; S403: Based on the relationship between the quality prediction value of aluminum hydroxide and the second data group, the quality assessment value of aluminum hydroxide is used as the quality prediction value of aluminum hydroxide, and the production environment parameters of the second data group are substituted into the relationship to perform function fitting, so as to obtain a finished product prediction and assessment formula that conforms to the aluminum hydroxide preparation process, and the preparation temperature, container pressure, sodium hydroxide solution flow rate, water flow rate and solution pH collected in real time by the preparation monitoring unit are substituted into the finished product prediction and assessment formula of the aluminum hydroxide preparation process, and the quality prediction value of aluminum hydroxide is obtained by calculation, thereby predicting the quality of aluminum hydroxide.

[0043] After completing the prediction, the production process needs to be regulated through the feedback regulation unit to adjust the production environment of aluminum hydroxide so that aluminum hydroxide better meets the preparation requirements.

[0044] Specifically, the feedback regulation unit adjusts the molar ratio of aluminum oxide to sodium hydroxide during the alkaline dissolution reaction of the bauxite powder by changing the flow rate of the sodium hydroxide solution, and jointly adjusts the solution pH of the bauxite powder leaching process and the aluminum hydroxide precipitation process by changing the water flow rate, and adjusts the preparation temperature of the bauxite powder leaching process and the aluminum hydroxide precipitation process. The steps are: Based on the relationship between the predicted value of aluminum hydroxide mass and the second data group, the preparation temperature, container pressure, sodium hydroxide solution flow rate, water flow rate and solution pH in the relationship are derived to predict the influence of the changing trend of the preparation temperature, container pressure, sodium hydroxide solution flow rate, water flow rate and solution pH on the quality of aluminum hydroxide. Based on the influence of the changing trend on the quality of aluminum hydroxide, the sodium hydroxide solution flow rate is changed to adjust the molar ratio of aluminum oxide to sodium hydroxide during the alkaline dissolution reaction of the bauxite powder, and the water flow rate is changed to adjust the solution pH of the bauxite powder leaching process and the aluminum hydroxide precipitation process together with the sodium hydroxide solution. At the same time, the preparation temperature of the bauxite powder leaching process and the aluminum hydroxide precipitation process is adjusted, so that the relationship between the predicted value of aluminum hydroxide mass and the second data group is derived with respect to the preparation temperature, container pressure, sodium hydroxide solution flow rate, water flow rate and solution pH, and then the data of the second data group is substituted into the derived relationship. The result tends to 0, and the quality prediction of aluminum hydroxide will reach the best quality at this time.

[0045] Specifically, data from the element detection unit, preparation monitoring unit, seed detection unit, detection prediction unit and feedback adjustment unit are transmitted to the display parameter adjustment unit via the network. The display parameter adjustment unit can visualize the data to determine whether the calculation results of the detection prediction unit and the feedback effect of the feedback adjustment unit are suitable for actual use, so as to avoid deviations in the production environment after feedback, which would result in lower quality of aluminum hydroxide.

[0046] Specifically, the display parameter adjustment unit can modify the base of the degree of influence of preparation temperature, container pressure, solution pH, sodium hydroxide solution flow rate and water flow rate on the quality of aluminum hydroxide in the finished product prediction evaluation formula of the aluminum hydroxide preparation process in a timely manner through manual adjustment, so as to prevent the base from being overfitted after generation, resulting in deviations in the judgment of the detection prediction unit.

[0047] The above-mentioned embodiments only express the preferred implementation modes of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present invention. It should be pointed out that, for a person skilled in the art, several modifications, improvements and substitutions can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the present invention patent shall be subject to the attached claims.

Claims

1. A quality inspection system for aluminum hydroxide production, characterized in that: It includes an element detection unit, a preparation monitoring unit, a seed detection unit, a detection prediction unit, a feedback adjustment unit and a display parameter adjustment unit; an element detection unit, comprising an XRF instrument, wherein the XRF instrument is used to irradiate the bauxite powder sample or the aluminum hydroxide sample with X-rays, and to capture characteristic X-rays emitted by the bauxite powder sample or the aluminum hydroxide sample, and to detect the contents of different elements in the bauxite powder sample or the aluminum hydroxide sample through the characteristic X-rays; A preparation monitoring unit includes a temperature sensor, a pressure sensor, a flow sensor and an online pH meter, wherein the temperature sensor is used to monitor the preparation temperature during the bauxite powder leaching process and the aluminum hydroxide precipitation process, the pressure sensor is used to monitor the container pressure during the bauxite powder leaching process, the flow sensor is used to monitor the flow rate of the sodium hydroxide solution and the water flow rate during the bauxite powder leaching process and the aluminum hydroxide precipitation process, and the online pH meter is used to detect the solution acidity and alkalinity during the bauxite powder leaching process and the aluminum hydroxide precipitation process; A seed detection unit, including an XRD instrument, the XRD instrument is used to irradiate the aluminum hydroxide sample with emitted X-rays and capture the diffracted X-rays reflected by the aluminum hydroxide sample, and detect the lattice type of the aluminum hydroxide sample through the diffracted X-rays; A detection prediction unit is used to evaluate the quality of aluminum hydroxide samples and the overall preparation process of aluminum hydroxide, and predict the quality of aluminum hydroxide based on the preparation temperature, container pressure, solution pH, sodium hydroxide solution flow rate and water flow rate monitored by the preparation monitoring unit, as well as the element content detected by the element detection unit and the lattice type detected by the seed crystal detection unit; A feedback regulating unit is used to adjust the molar ratio of aluminum oxide to sodium hydroxide during the alkaline dissolution reaction of the bauxite powder by changing the flow rate of the sodium hydroxide solution based on the prediction result of the detection and prediction unit, and to adjust the pH of the solution during the bauxite powder leaching process and the aluminum hydroxide precipitation process by changing the flow rate of water, and to adjust the preparation temperature of the bauxite powder leaching process and the aluminum hydroxide precipitation process; The display and parameter adjustment unit includes a display and a host device, which is used to display all test results on the display and adjust the production environment parameters of aluminum hydroxide preparation by controlling the host device.

2. A quality inspection system for aluminum hydroxide production according to claim 1, characterized in that, The steps for detecting the content of different elements in bauxite powder samples or aluminum hydroxide samples by characteristic X-rays are as follows: S101: placing the prepared bauxite powder sample tablet or aluminum hydroxide sample tablet on a dedicated sample table, setting the voltage and current of the X-ray tube of the XRF instrument, and selecting the X-ray wavelength; S102: turning on the X-ray tube of the XRF instrument, the X-ray tube of the XRF instrument emits incident X-rays, the incident X-rays irradiate the bauxite powder sample tablet or the aluminum hydroxide sample tablet, so that the bauxite powder sample tablet or the aluminum hydroxide sample tablet emits characteristic X-rays; S103: The detector of the XRF instrument collects characteristic X-rays and generates an XRF spectrum. Based on the peak height in the XRF spectrum, data is compared with different standard samples to determine the type and content of elements in the sample.

3. A quality detection system for aluminum hydroxide production according to claim 2, characterized in that, The element detection unit samples the bauxite powder used in each aluminum hydroxide preparation process and detects the element content, prepares the sodium hydroxide solution based on the content of each element, samples and evaporates the waste liquid generated by each aluminum hydroxide preparation, and detects the element content of the evaporated waste liquid sample to determine whether the waste liquid will be involved in the next aluminum hydroxide preparation.

4. A quality detection system for aluminum hydroxide production according to claim 3, characterized in that, The steps for detecting the lattice type of aluminum hydroxide sample by diffraction X-ray are: S201: placing the prepared aluminum hydroxide sample pressed tablet on a dedicated sample table, setting the voltage and current of the X-ray tube of the XRD instrument, and selecting the X-ray wavelength; S202: Calibrate using a standard silicon powder sample to ensure the accuracy of the instrument; S203: Turn on the X-ray tube of the XRD instrument, the X-ray tube of the XRD instrument emits incident X-rays, the incident X-rays irradiate the aluminum hydroxide sample pellet, and form diffracted X-rays; S204: The detector of the XRD instrument collects diffracted X-rays and generates an XRD spectrum. Based on the peak height in the XRD spectrum, data is compared with that of an aluminum hydroxide standard sample to determine the lattice type in the aluminum hydroxide sample.

5. A quality inspection system for aluminum hydroxide production according to claim 4, characterized in that, The steps for the detection prediction unit to evaluate the quality of aluminum hydroxide samples are as follows: S301: drying the aluminum hydroxide sample and placing it in an element detection unit and a seed crystal detection unit to perform element detection and seed crystal detection respectively; S302: The detection results of the element detection unit and the seed crystal detection unit are input into the detection prediction unit to perform quality evaluation calculation of the aluminum hydroxide sample. The quality evaluation calculation formula of the aluminum hydroxide sample is: ； in, is the mass evaluation value of the aluminum hydroxide sample, 2.89 is the relative molecular mass ratio between aluminum hydroxide and aluminum when the molecular quantity is the same, is the aluminum content in the aluminum hydroxide sample, is the ratio of the desired aluminum hydroxide lattice type to the lattice type of the aluminum hydroxide sample.

6. A quality inspection system for aluminum hydroxide production according to claim 5, characterized in that, The steps for the detection and prediction unit to conduct an overall assessment of the aluminum hydroxide preparation process are as follows: Before each preparation of aluminum hydroxide, the detection prediction unit will record the total weight of the bauxite powder. After each detection by the element detection unit and the seed detection unit, the aluminum element content result and the required aluminum hydroxide lattice type ratio result will be entered into the detection prediction unit, and the detection prediction unit will also record the total weight of aluminum hydroxide, so as to evaluate and calculate the preparation process of aluminum hydroxide. The preparation process evaluation calculation formula is: ； in, is the evaluation value of the aluminum hydroxide preparation process, is the aluminum content in the aluminum hydroxide sample, is the ratio of the desired aluminum hydroxide lattice type to the lattice type of the aluminum hydroxide sample, is the aluminum content in bauxite powder, is the total mass of bauxite powder, is the total mass of aluminum hydroxide prepared.

7. A quality inspection system for aluminum hydroxide production according to claim 6, characterized in that: The detection prediction unit predicts the quality of aluminum hydroxide based on the preparation temperature, container pressure, solution pH, sodium hydroxide solution flow rate and water flow rate monitored by the preparation monitoring unit, the element content detected by the element detection unit and the lattice type detected by the seed detection unit. The steps are as follows: S401: During the preparation process of each batch of aluminum hydroxide, the detection prediction unit reads the preparation temperature, container pressure, sodium hydroxide solution flow rate, solution pH, and water flow rate collected by the preparation monitoring unit once every period of time, and saves these collected data as a two-dimensional first data group, the first dimension data of the first data group are different production environment parameters at the same time, the second dimension data of the first data group are the same production environment parameters at different times, and the second dimension data of the first data group are averaged to obtain a one-dimensional second data group; S402: The relationship between the predicted value of aluminum hydroxide mass and the second data set is: ； in, is the predicted value of aluminum hydroxide quality, 3 is the number of aluminum hydroxide preparation processes, the aluminum hydroxide preparation process includes bauxite powder leaching process and aluminum hydroxide precipitation process, the aluminum hydroxide precipitation process is divided into aluminum hydroxide crystallization process and aluminum hydroxide crystal growth process, The first The number of production environment parameters for each process, The first In the process The base number of the influence of production environment parameters on the quality of aluminum hydroxide, The first In the process Production environment parameters; S403: Based on the relationship between the quality prediction value of aluminum hydroxide and the second data group, the quality assessment value of aluminum hydroxide is used as the quality prediction value of aluminum hydroxide, and the production environment parameters of the second data group are substituted into the relationship to perform function fitting, so as to obtain a finished product prediction and assessment formula that conforms to the aluminum hydroxide preparation process, and the preparation temperature, container pressure, sodium hydroxide solution flow rate, water flow rate and solution pH collected in real time by the preparation monitoring unit are substituted into the finished product prediction and assessment formula of the aluminum hydroxide preparation process, and the quality prediction value of aluminum hydroxide is obtained by calculation, thereby predicting the quality of aluminum hydroxide.

8. A quality inspection system for aluminum hydroxide production according to claim 7, characterized in that: The feedback regulation unit adjusts the molar ratio of aluminum oxide to sodium hydroxide during the alkaline dissolution reaction of the bauxite powder by changing the flow rate of the sodium hydroxide solution, and jointly adjusts the solution pH of the bauxite powder leaching process and the aluminum hydroxide precipitation process by changing the water flow rate, and adjusts the preparation temperature of the bauxite powder leaching process and the aluminum hydroxide precipitation process. The steps are as follows: Based on the relationship between the predicted value of aluminum hydroxide mass and the second data group, the preparation temperature, container pressure, sodium hydroxide solution flow rate, water flow rate and solution pH in the relationship are derived to predict the influence of the changing trend of the preparation temperature, container pressure, sodium hydroxide solution flow rate, water flow rate and solution pH on the quality of aluminum hydroxide. Based on the influence of the changing trend on the quality of aluminum hydroxide, the sodium hydroxide solution flow rate is changed to adjust the molar ratio of aluminum oxide to sodium hydroxide during the alkaline dissolution reaction of the bauxite powder, and the water flow rate is changed to adjust the solution pH of the bauxite powder leaching process and the aluminum hydroxide precipitation process together with the sodium hydroxide solution. At the same time, the preparation temperature of the bauxite powder leaching process and the aluminum hydroxide precipitation process is adjusted, so that the relationship between the predicted value of aluminum hydroxide mass and the second data group is derived with respect to the preparation temperature, container pressure, sodium hydroxide solution flow rate, water flow rate and solution pH, and then the data of the second data group is substituted into the derived relationship. The result tends to 0, and the quality prediction of aluminum hydroxide will reach the best quality at this time.

9. A quality inspection system for aluminum hydroxide production according to claim 8, characterized in that: The data of the element detection unit, preparation monitoring unit, seed detection unit, detection prediction unit and feedback adjustment unit are transmitted to the display parameter adjustment unit through the network, and the display parameter adjustment unit can visualize the data.

10. A quality inspection system for aluminum hydroxide production according to claim 9, characterized in that: The display parameter adjustment unit modifies the base of the degree of influence of preparation temperature, container pressure, solution pH, sodium hydroxide solution flow rate and water flow rate on the quality of aluminum hydroxide in the finished product prediction evaluation formula of the aluminum hydroxide preparation process through manual adjustment.

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