Method for measuring and analyzing transformation rate and acidification rate of lithium ore

Abstract

The invention provides a method for measuring and analyzing the transformation rate and the acidification rate of lithium ore. The rapid and accurate determination of the transformation rate and the acidification rate is realized through the steps of preparing a lithium element standard solution, detecting the content of total lithium and soluble lithium in a baking material produced in a transformation baking process, the content of lithium element in a clinker produced in an acidification baking process and the content of soluble lithium in filter residues by using an inductively coupled plasma mass spectrometer, and the like. The transformation roasting effect and the acidification roasting effect are regularly detected, the lithium extraction effect in the production process is analyzed according to the comparison result between the measured transformation rate and acidification rate and the threshold value / multiple continuous measurement values, and the working procedure influencing the lithium element extraction yield or the working procedure possibly enabling the lithium element extraction yield to have the gliding trend in early warning in the production process is pointed out; and the operation condition of the production process can be adjusted and optimized by technicians in a targeted manner through timely feedback of abnormity or early warning.

Description

Technical Field

[0001] The present invention relates to the field of lithium extraction yield measurement from ores, and specifically to a method for determining and analyzing the transformation rate and acidification rate of lithium ores. Background Art

[0002] Currently, the operation status of the lithium extraction production process from ores is mainly evaluated based on the measured yield index. That is, by comparing the lithium element content in the lithium ore raw material and the produced lithium salt product, the extraction efficiency of the lithium element in the ore by the production process is obtained to judge the quality of the operation.

[0003] Patent CN201810554232.X discloses a method for rapidly analyzing the lithium content in spodumene samples resistant to hydrofluoric acid. By adding a certain proportion of HNO 3 and HF to the spodumene sample for digestion, after constant volume with ultrapure water, the lithium content in the spodumene sample is determined by the standard addition method using an inlaid liquid cathode glow discharge spectrometer. The paper "Determination of Lithium Oxide in Spodumene by Inductively Coupled Plasma Emission Spectrometry" published by Xu Xiuping, Li Bo, etc. records that the spodumene sample is digested by a variety of mixed acid systems, then dissolved and made up to volume with hydrochloric acid and deionized water, and then the content of lithium oxide in the sample is determined by an inductively coupled plasma spectrometer. Similarly, patent CN202410650883.4 discloses a method for rapidly determining the lithium content in lithium ore samples. First, a certain amount of ammonium bifluoride and hydrofluoric acid are added to the lithium ore sample for heating digestion, and then aqua regia is added for hot dissolution. After cooling, making up to volume and clarifying, the lithium ion concentration is determined by inductively coupled plasma emission spectrometry or inductively coupled plasma emission spectrometry to obtain the lithium content in the lithium ore sample.

[0004] The above patents and papers disclose the detection methods for the lithium oxide content in lithium ores, but do not further give the methods for determining the yield of the lithium extraction process or process, and the yield data cannot be obtained through the above methods. And during the detection process, the ores are digested by mixing a variety of acid (salt) solutions, and it is necessary to consider adjusting the specific gravity of each solution. There is also a risk of splashing of the acid solution during the mixing process. Some methods involve adding strong acids at high temperatures, resulting in complex, difficult and dangerous detection methods. At the same time, the storage requirements and procurement costs of a variety of acid solutions are also very high.

[0005] The paper "Research on the Yield of Spodumene during Roasting and Acidification Leaching Process" published by Li Zhong, Li Huan, etc. explored the influence of parameters such as roasting time, roasting temperature, acidification time, acidification temperature, and material-acid ratio on the yield of spodumene, and gave the optimal value ranges of the above parameters, but did not give the measurement methods for the transformation rate and acidification rate, nor analyzed the changes of the transformation rate and acidification rate indicators during the production process.

[0006] In addition, evaluating the operation situation by comparing the lithium element content in the lithium ore raw material and the final lithium salt product lacks regular monitoring of the lithium extraction yield during the production process, and thus it is impossible to give timely feedback and effective warning for the working conditions where the yield is lower than the production requirements; moreover, comparing the lithium element content in the spodumene raw material and the final lithium salt product cannot provide the direct cause for the low lithium element content in the product, and it is impossible to give targeted suggestions for optimizing the production process. Generally, technicians can only find the problem by checking each process one by one, resulting in low work efficiency.

[0007] To sum up, in the prior art, the method for detecting lithium elements in lithium ore is to use a combination of multiple acid solutions for digestion, which has problems such as complex processes, high difficulty, high danger, and high costs. Moreover, there is no complete standardized and normalized determination method for the transformation rate and acidification rate of lithium ore, and it is impossible to achieve rapid determination of the transformation rate and acidification rate, nor can it effectively analyze the changes in the transformation rate and acidification rate during the production process to prompt or warn the processes that cause the low or reduced lithium extraction yield. Once a problem occurs, the maintenance efficiency is relatively low. Summary of the Invention

[0008] In order to overcome the deficiencies in the prior art regarding the determination and analysis of the lithium ore yield, the present invention provides a method for determining the transformation rate of lithium ore, which includes the following steps: Step A1, preparing a lithium element standard solution and drawing a standard curve; Step A2, detecting the total lithium content of the calcined material produced by the transformation roasting process; Step A3, detecting the soluble lithium content of the calcined material produced by the transformation roasting process; Step A4, determining the transformation rate.

[0009] Furthermore, the specific process of Step A1 for preparing a lithium element standard solution and drawing a standard curve is as follows: Take a certain amount of lithium carbonate sample and place it in a vacuum drying oven, and dry it at 105 °C for 2 hours; After cooling for 30 minutes, weigh 2.4729 g of lithium carbonate sample with an analytical balance, place it in a 100 ml beaker, add 30 ml of water, and then dropwise add 10 ml of (1+1) sulfuric acid solution to dissolve the lithium carbonate sample; Heat the dissolved sample to boiling with a universal electric furnace to remove CO 2 , after cooling for 30 minutes, transfer the solution in the beaker to a 1000 ml volumetric flask, and add water to dilute to the scale of the 1000 ml volumetric flask to obtain a 1000 μg / ml lithium element standard solution (calculated as Li 2 O); Take a 1000 μg / ml lithium element standard solution, and prepare a series of lithium element standard solutions through stepwise dilution method with concentrations of 0 μg / ml, 1 μg / ml, 2 μg / ml, 3 μg / ml, 4 μg / ml, 5 μg / ml, and 6 μg / ml. Use an inductively coupled plasma mass spectrometer to detect the series of lithium element standard solutions, and draw a standard curve based on the detection results and the concentration relationship.

[0010] Further, the specific process for detecting the total lithium content of the calcined material produced in the transformation roasting process in step A2 is as follows: Step A2.1, prepare the total lithium solution of the calcined material: Take a certain amount of the calcined material produced in the transformation roasting process during the production of lithium by the sulfuric acid method using spodumene as the raw material as a sample. Dry the sample at 105°C - 110°C for 2 hours, and grind it to 200 mesh after cooling. Weigh 0.1500 g of the ground sample, place it in a polytetrafluoroethylene crucible, moisten it with a small amount of pure water, add 20 ml of hydrofluoric acid (density 1.15 g / ml), and gently shake the crucible to mix evenly. Place the crucible in a sand bath at 150 - 200°C and heat and evaporate until the sample becomes a wet salt state. After taking out the crucible and cooling it to room temperature, add 2 ml of (1 + 1) sulfuric acid, stir gently with a glass rod, and then add 20 ml of pure water. Place the crucible in a sand bath at 150°C and heat until the sample is completely dissolved. After taking out the crucible and cooling it to room temperature, transfer the solution in the crucible to a 250 ml volumetric flask, add water to dilute to the scale of the 250 ml volumetric flask, shake well, let it stand for 15 minutes, and filter. Pipette 10 ml of the filtrate, put it into a 100 ml volumetric flask, add 2 ml of (1 + 1) sulfuric acid, add water to dilute to the scale of the 100 ml volumetric flask, shake well, and obtain the total lithium solution of the calcined material. Step A2.2, measure the concentration of the total lithium solution of the calcined material: Prepare 3 total lithium solutions of the calcined material according to step A2.1 for the same batch of calcined material samples. Use an inductively coupled plasma mass spectrometer to detect the 3 total lithium solutions of the calcined material, and obtain the lithium concentrations of the solutions as T 1 Li 2 O μg / ml, T 2 Li 2 O μg / ml, T 3 Li 2 O μg / ml. Take the average value TLi 2 O μg / ml of the three concentrations, record it as the total lithium content of the calcined material, and save the data.

[0011] Further, the specific process for detecting the soluble lithium content of the calcined material produced in the transformation roasting process in step A3 is as follows: Step A3.1, prepare soluble lithium solution from roasted material: Take a certain amount of roasted material produced in the transformation roasting process during the production of lithium by the sulfuric acid method using spodumene as raw material as a sample. Dry the sample at 105°C - 110°C for 2 hours, and grind it to 200 mesh after cooling. Weigh 0.1500 g of the ground sample and place it in a ceramic crucible. Add 3.5 ml of (4 + 1) sulfuric acid, and gently shake the crucible to mix evenly. Cover the crucible with a ceramic lid and send it into a muffle furnace. Heat it to 260°C and keep it at a constant temperature for 30 minutes. After taking out the crucible and cooling it to room temperature, transfer the solution in the crucible to a 250 ml volumetric flask, add water to dilute it to the scale of the 250 ml volumetric flask, shake well, let it stand for 15 minutes, and then filter. Pipette 10 ml of the filtrate and put it into a 100 ml volumetric flask. Add 2 ml of (1 + 1) sulfuric acid, and add water to the scale of the 100 ml volumetric flask. Shake well to obtain the soluble lithium solution from the roasted material. Step A3.2, measure the concentration of the soluble lithium solution from the roasted material: Prepare 3 portions of soluble lithium solution from the roasted material according to Step A3.1 for the same batch of roasted material samples. Use an inductively coupled plasma mass spectrometer to detect the 3 portions of soluble lithium solution from the roasted material, and obtain the lithium concentrations of the solutions as β 1 Li 2 O μg / ml, β 2 Li 2 O μg / ml, β 3 Li 2 O μg / ml respectively. Take the average value βLi 2 O μg / ml of the three concentrations, record it as the soluble lithium content of the roasted material, and save the data.

[0012] Furthermore, the specific process for measuring the transformation rate in Step A4 is as follows: Substitute the total lithium content TLi 2 O μg / ml of the roasted material obtained in Step A2 and the soluble lithium content βLi 2 O μg / ml of the roasted material obtained in Step A3 into the transformation rate , calculate the transformation rate, and save the data.

[0013] The present invention also provides a method for measuring the acidification rate of lithium ore, including the following steps: Step B1, prepare a lithium element standard solution and draw a standard curve; Step B2, detect the lithium element content of the clinker produced in the acidification roasting process; Step B3, detect the soluble lithium content of the filter residue produced in Step B2; Step B4, measure the acidification rate.

[0014] Further, the specific process of preparing the lithium element standard solution and drawing the standard curve in step B1 of the method for measuring the acidification rate of lithium ore is the same as that in step B1 of the aforementioned method for measuring the transformation rate of lithium ore.

[0015] Further, the specific process of detecting the lithium element content of the clinker produced in the acidification roasting process in step B2 is as follows: Step B2.1, preparing the clinker solution: Take a certain amount of the clinker produced in the acidification roasting process during the production of lithium by the sulfuric acid method using spodumene as the raw material as a sample. Weigh 0.2000 g of the sample and place it in a 250 ml beaker, and add 50 ml of pure water; Put a magnetic stir bar in the beaker, cover it with a cover glass, place the beaker in the middle of the stirrer, and stir for 20 minutes; Add 5 ml of (1+1) sulfuric acid, stir evenly, transfer it to a 250 ml volumetric flask, add water to dilute to the scale of the 250 ml volumetric flask, shake well, let it stand for 15 minutes, filter to obtain the filtrate and the filter residue; Absorb 10 ml of the filtrate, put it into a 100 ml volumetric flask, add 2 ml of (1+1) sulfuric acid, add water to dilute to the scale of the 100 ml volumetric flask, shake well, let it stand for 15 minutes to obtain the clinker solution; Step B2.2, measuring the concentration of the clinker solution: Prepare 3 portions of the clinker solution according to step B2.1 for the same batch of clinker samples, detect the 3 portions of the clinker solution using an inductively coupled plasma mass spectrometer, and obtain the lithium concentrations of the solutions as S 1 Li 2 O μg / ml, S 2 Li 2 O μg / ml, S 3 Li 2 O μg / ml. Take the average value SLi 2 O μg / ml of the three concentrations, record it as the lithium element content of the clinker, and save the data.

[0016] Further, the specific process of detecting the soluble lithium content of the filter residue produced in step B2 is as follows: Step B3.1, preparing the soluble lithium solution of the filter residue: Dry the filter residue produced in step B2 at 105 °C - 110 °C for 2 hours, and grind it to 200 mesh after cooling; Weigh the ground filter residue and place it in a ceramic crucible, add 3.5 ml of (4+1) sulfuric acid, and gently shake the crucible to mix evenly; Cover the crucible with a ceramic lid and send it into a muffle furnace, heat it up to 260 °C, and keep it at a constant temperature for 30 minutes; After taking out the crucible and cooling it to room temperature, transfer the solution in the crucible to a 250 ml volumetric flask, add water to dilute to the scale of the 250 ml volumetric flask, shake well, let stand for 15 minutes, and filter; Take 10 ml of the filtrate and put it into a 100 ml volumetric flask, add 2 ml of (1+1) sulfuric acid, add water to the scale of the 100 ml volumetric flask, shake well to obtain a soluble lithium solution of the filter residue; Step B3.2, measure the concentration of the soluble lithium solution of the filter residue: In step B2, a total of three portions of filter residue are produced. According to step B3.1, soluble lithium solutions of the filter residue are prepared respectively. Use an inductively coupled plasma mass spectrometer to detect the soluble lithium solution of the filter residue. According to the standard curve, the lithium concentrations of the solutions are ST 1 Li 2 O μg / ml, ST 2 Li 2 O μg / ml, ST 3 Li 2 O μg / ml. Take the average value STLi 2 O μg / ml of the three concentrations, record it as the soluble lithium content of the filter residue, and save the data.

[0017] Furthermore, the specific process for measuring the acidification rate in step B4 is as follows: The lithium element content SLi 2 O μg / ml of the clinker obtained in step B2, and the soluble lithium content STLi 2 O μg / ml of the filter residue obtained in step B3 are substituted into the acidification rate , calculate the acidification rate, and save the data.

[0018] In addition, the present invention also discloses a method for analyzing the transformation rate and acidification rate of lithium ore. By measuring and analyzing the transformation rate and acidification rate data, judge the operation conditions of the transformation roasting process and the acidification roasting process, which specifically include the following steps: Step S1, set the transformation rate threshold and acidification rate threshold that meet the requirements of reaching the standard and achieving full production in the sulfuric acid method for extracting lithium from ore; Step S2, regularly extract the roasted materials produced in the transformation roasting process as measurement samples and measure the transformation rate; Step S3, regularly extract the clinkers produced in the acidification roasting process as measurement samples and measure the acidification rate; Step S4, compare the data and analyze and judge whether it is necessary to prompt an abnormality or give an early warning: Step S4.1, compare the measured transformation rate and acidification rate data with the transformation rate threshold and acidification rate threshold, and judge whether the operation conditions of the transformation roasting process and the acidification roasting process are abnormal: When the measured conversion rate < the conversion rate threshold, it indicates that the operation of the conversion roasting process cannot meet the actual production requirements, and it is necessary to optimize the operation parameters and related equipment of the conversion roasting process, and prompt that the operation of the conversion roasting process is abnormal; When the measured acidification rate < the acidification rate threshold, it indicates that the operation of the acidification roasting process cannot meet the actual production requirements, and it is necessary to optimize the operation parameters and related equipment of the acidification roasting process, and prompt that the operation of the acidification roasting process is abnormal.

[0019] Step S4.2, compare the continuously measured conversion rate and acidification rate data, and determine whether to prompt a warning for the operation of the conversion roasting process and the acidification roasting process: When the conversion rate α measured twice in a row 1 、α 2 Compared, it drops by more than 1.0%, that is, α 1 -α 2 > 1.0%, or the conversion rate α measured four times in a row 1 、α 2 、α 3 、α 4 Compared, they all drop, that is, α 1 > α 2 > α 3 > α 4 It indicates that the operation of the conversion roasting process continues to deteriorate, and a warning is issued; When the acidification rate η measured twice in a row 1 、η 2 Compared, it drops by more than 1.0%, that is, η 1 -η 2 > 1.0%, or the acidification rate η measured four times in a row 1 、η 2 、η 3 、η 4 Compared, they all drop, that is, η 1 > η 2 > η 3 > η 4 It indicates that the operation of the acidification roasting process continues to deteriorate, and a warning is issued.

[0020] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. The present invention provides a method for determining the transformation rate and acidification rate of lithium ore. By preparing a lithium element standard solution and using an inductively coupled plasma mass spectrometer to detect the total lithium content and soluble lithium content of the roasted material produced in the transformation roasting process, as well as the lithium element content of the clinker and the soluble lithium content of the filter residue produced in the acidification roasting process, etc., the transformation rate and acidification rate of lithium extraction from ore by the sulfuric acid method are determined. The above-mentioned solution preparation and detection processes are based on existing complete experimental instruments, and the specific operation procedures of the method steps are clearly given. The operation procedures are simple and standardized, and the results are highly reliable, realizing the rapid and accurate determination of the transformation rate and acidification rate.

[0021] 2. The method for determining the transformation rate and acidification rate proposed by the present invention makes full use of the characteristic that natural α-spodumene generally only reacts with hydrofluoric acid. By adding an appropriate amount of hydrofluoric acid, that is, using only hydrofluoric acid as the digestion acid for the roasted material, digestion is achieved. Compared with the prior art in which a mixed solution composed of a variety of acid solutions is used for digestion, the present invention does not involve the quantitative mixing and preparation of a variety of acid solutions, is not prone to errors and is not prone to danger, is easy to standardize and has high safety.

[0022] 3. The present invention provides a method for analyzing the transformation rate and acidification rate of lithium ore. By adding regular detection of the transformation rate of transformation roasting and the acidification rate of acidification roasting during the production process of lithium extraction from spodumene by the sulfuric acid method, and according to the comparison results between the measured transformation rate and acidification rate and the threshold / multiple consecutive measurement values, the lithium extraction effect of the production process is analyzed, and the processes affecting the lithium element extraction yield in production are pointed out or the processes that may cause a downward trend in the lithium element extraction yield are warned. Timely feedback of abnormalities or warnings enables technicians to adjust and optimize the operation of the production process targeted, solving the problem of the lag in the method of evaluating the lithium extraction effect of lithium salt production by comparing the lithium element content in the ore raw material and the final lithium salt product, and giving the specific processes affecting the lithium element extraction yield, clarifying the direction of adjustment and optimization, and helping to improve the maintenance efficiency.

[0023] 4. The present invention also gives the specific operations of the steps for judging the processes affecting the lithium element extraction yield and warning the downward trend of the lithium element extraction yield, as well as the reference values for various working conditions, realizing the standardization and standardization of the operation of comparing data, analyzing, judging, prompting abnormalities or warning processes. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a flow chart of the method for determining the transformation rate of lithium ore of the present invention.

[0025] Figure 2 It is a flow chart of the method for determining the acidification rate of lithium ore of the present invention.

[0026] Figure 3 It is a flow chart of the method for analyzing the transformation rate and acidification rate of lithium ore of the present invention. Detailed implementation manners

[0027] To make the objectives, technical solutions and advantages of the present invention clearer, the implementation manners of the present invention will be further described below with reference to the accompanying drawings. The following is a relatively preferable one among multiple possible embodiments of the present invention, which is intended for a basic understanding of the present invention, but is not intended to identify the key or decisive elements of the present invention or limit the scope to be protected.

[0028] In the description of the present invention, it should be noted that unless otherwise clearly specified and limited, the terms "installation" and "connection" should be understood in a broad sense. For example, it 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 directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific situations.

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments, but the implementation manners of the present invention are not limited thereto.

[0030] Embodiment 1: This embodiment provides a method for measuring the transformation rate of lithium ore, as Figure 1 shown, including the following steps: Step A1: Prepare a lithium element standard solution and draw a standard curve; Step A2: Detect the total lithium content of the calcined material produced in the transformation roasting process; Step A3: Detect the soluble lithium content of the calcined material produced in the transformation roasting process; Step A4: Measure the transformation rate.

[0031] Embodiment 2: Based on Embodiment 1, this embodiment describes the specific operations of Step A1 for preparing a lithium element standard solution and drawing a standard curve. The specific process is as follows: Take 20 g of lithium carbonate sample and place it in a vacuum drying oven, and dry it at 105 °C for 2 hours; After cooling for 30 minutes, weigh 2.4729 g of lithium carbonate sample with an analytical balance, place it in a 100 ml beaker, add 30 ml of water, and then add 10 ml of (1 + 1) sulfuric acid solution dropwise to dissolve the lithium carbonate sample; Heat the dissolved sample to boiling with a universal electric furnace to remove CO 2 , and after cooling for 30 minutes, transfer the solution in the beaker to a 1000 ml volumetric flask, and add water to dilute it to the scale of the 1000 ml volumetric flask to obtain a 1000 μg / ml lithium element standard solution (in terms of Li 2O meter); Take 1000μg / ml lithium standard solution, and prepare a series of lithium standard solutions with concentrations of 0μg / ml, 1μg / ml, 2μg / ml, 3μg / ml, 4μg / ml, 5μg / ml, and 6μg / ml by stepwise dilution method. Use inductively coupled plasma mass spectrometry to detect the series of lithium standard solutions, and draw a standard curve based on the relationship between the test results and concentrations.

[0032] The other parts of this embodiment are the same as those of Embodiment 1, and thus will not be described in detail.

[0033] Embodiment 3: Based on Example 1, this example describes the specific operation of detecting the total lithium content of the roasted material produced in the transition roasting process in step A2. The specific process is: Step A2.1, preparing a roasted material full lithium solution: Take 10g of the roasted material produced by the transformation roasting process in the production process of lithium extraction by sulfuric acid method using spodumene as raw material as a sample, dry the sample at 105℃-110℃ for 2 hours, and grind it into 200 mesh after cooling; Weigh 0.1500 g of the ground sample, place it in a polytetrafluoroethylene crucible, moisten it with a small amount of pure water, add 20 ml of hydrofluoric acid (density 1.15 g / ml), and gently shake the crucible to mix; Place the crucible in a sand bath at 150-200°C and heat and evaporate until the sample is in the form of wet salt; After the crucible is taken out and cooled to room temperature, 2 ml (1+1) sulfuric acid is added, and it is stirred lightly with a glass rod, and then 20 ml of pure water is added; Place the crucible in a 150°C sand bath and heat it to completely dissolve the sample; After taking out the crucible and cooling it to room temperature, transfer the solution in the crucible to a 250ml volumetric flask, add water to dilute to the 250ml volumetric flask mark, shake well, let stand for 15 minutes, and filter; Take 10ml of the filtrate and put it into a 100ml volumetric flask, add 2ml (1+1) sulfuric acid, dilute with water to the 100ml volumetric flask mark, shake well, and obtain a full lithium solution of the roasted material; Step A2.2, measuring the concentration of the roasted material full lithium solution: From the same batch of roasted material samples, three roasted material full lithium solutions were prepared according to step A2.1, and the three roasted material full lithium solutions were detected using an inductively coupled plasma mass spectrometer. According to the standard curve, the lithium concentrations of the solutions were 3.602 μg / ml, 3.605 μg / ml, and 3.599 μg / ml, respectively. The average value of the three concentrations, 3.602 μg / ml, was taken as the roasted material full lithium content, and the data was saved.

[0034] Other parts of this embodiment are the same as those of Embodiment 1, so they will not be described in detail.

[0035] Embodiment 4: Based on Embodiment 1, this embodiment describes the specific operation of detecting the soluble lithium content of the calcined material produced in the transformation roasting process in Step A3. The specific process is as follows: Step A3.1, preparing the soluble lithium solution of the calcined material: Take 10 g of the calcined material produced in the transformation roasting process during the production of lithium by the sulfuric acid method using spodumene as the raw material as a sample. Dry the sample at 105°C - 110°C for 2 hours. After cooling, grind it to 200 meshes; Weigh 0.1500 g of the ground sample and place it in a ceramic crucible. Add 3.5 ml of (4 + 1) sulfuric acid and gently shake the crucible to mix evenly; Cover the crucible with a ceramic lid and send it into a muffle furnace. Heat it up to 260°C and keep it at a constant temperature for 30 minutes; After taking out the crucible and cooling it to room temperature, transfer the solution in the crucible to a 250 ml volumetric flask, add water to dilute it to the scale of the 250 ml volumetric flask, shake well, let it stand for 15 minutes, and filter; Absorb 10 ml of the filtrate and put it into a 100 ml volumetric flask. Add 2 ml of (1 + 1) sulfuric acid and add water to the scale of the 100 ml volumetric flask, shake well to obtain the soluble lithium solution of the calcined material; Step A3.2, measuring the concentration of the soluble lithium solution of the calcined material: Prepare 3 portions of the soluble lithium solution of the calcined material from the same batch of calcined material samples according to Step A3.1. Use an inductively coupled plasma mass spectrometer to detect the 3 portions of the soluble lithium solution of the calcined material. According to the standard curve, the lithium concentrations of the solutions are 3.5047 μg / ml, 3.5149 μg / ml, and 3.5155 μg / ml respectively. Take the average value of the three concentrations, 3.5117 μg / ml, record it as the soluble lithium content of the calcined material, and save the data.

[0036] Other parts of this embodiment are the same as those of Embodiment 1, so they will not be described in detail.

[0037] Embodiment 5: Based on Embodiment 3 and Embodiment 4, this embodiment describes the specific operation of determining the transformation rate in Step A4. The specific process is as follows: Substitute the total lithium content of 3.602 μg / ml of the calcined material obtained in Embodiment 3 and the soluble lithium content of 3.5117 μg / ml of the calcined material obtained in Embodiment 4 into the transformation rate , and obtain the transformation rate α = 97.49%, and save the data.

[0038] Other parts of this embodiment are the same as those of Embodiment 1, so they will not be described in detail.

[0039] Embodiment 6: This embodiment provides a method for measuring the acidification rate of lithium ore, as Figure 2 shown, including the following steps: Step B1: Prepare a lithium element standard solution and draw a standard curve; Step B2: Detect the lithium element content of the clinker produced in the acidification roasting process; Step B3: Detect the soluble lithium content of the filter residue produced in Step B2; Step B4: Measure the acidification rate.

[0040] Example 7: Based on Example 6, this embodiment describes the specific operation of detecting the lithium element content of the clinker produced in the acidification roasting process in Step B2. The specific process is as follows: Step B2.1, Prepare a clinker sample solution: Take 10 g of the clinker produced in the acidification roasting process during the production of lithium by the sulfuric acid method using spodumene as the raw material as a sample. Weigh 0.2000 g of the sample and place it in a 250 ml beaker, and add 50 ml of pure water; Put a magnetic stir bar in the beaker, cover it with a cover glass, place the beaker in the middle of the stirrer, and stir for 20 minutes; Add 5 ml of (1+1) sulfuric acid, stir evenly, transfer it to a 250 ml volumetric flask, add water to dilute to the scale of the 250 ml volumetric flask, shake well, let it stand for 15 minutes, filter, and obtain a filtrate and a filter residue; Absorb 10 ml of the filtrate, put it into a 100 ml volumetric flask, add 2 ml of (1+1) sulfuric acid, add water to dilute to the scale of the 100 ml volumetric flask, shake well, let it stand for 15 minutes, and obtain a clinker solution; Step B2.2, Measure the concentration of the clinker solution: Prepare 3 clinker solutions from the same batch of clinker samples according to Step B2.1, and use an inductively coupled plasma mass spectrometer to detect the 3 clinker solutions. According to the standard curve, the lithium concentrations of the solutions are 3.4276 μg / ml, 3.4346 μg / ml, and 3.4270 μg / ml respectively. Take the average value of the three concentrations, 3.4297 μg / ml, record it as the lithium element content of the clinker, and save the data.

[0041] The other parts of this embodiment are the same as those of Example 6, so they will not be described in detail.

[0042] Example 8: Based on Example 6, this embodiment describes the specific operation of detecting the soluble lithium content of the filter residue produced in Step B2 in Step B3. The specific process is as follows: Step B3.1, Prepare a filter residue soluble lithium solution: Dry the filter residue produced in step B2 at 105°C - 110°C for 2 hours. After cooling, grind it to 200 mesh; Weigh the ground filter residue and place it in a ceramic crucible. Add 3.5 ml of (4+1) sulfuric acid and gently shake the crucible to mix evenly; Cover the crucible with a ceramic lid and place it in a muffle furnace. Heat it to 260°C and keep it at a constant temperature for 30 minutes; After taking out the crucible and cooling it to room temperature, transfer the solution in the crucible to a 250 ml volumetric flask, add water to dilute it to the scale of the 250 ml volumetric flask, shake well, let it stand for 15 minutes, and then filter; Pipette 10 ml of the filtrate into a 100 ml volumetric flask, add 2 ml of (1+1) sulfuric acid, add water to the scale of the 100 ml volumetric flask, shake well to obtain the soluble lithium solution of the filter residue; Step B3.2, measure the concentration of the soluble lithium solution of the filter residue: A total of three portions of filter residue were produced in step B2. The soluble lithium solutions of the filter residue were prepared respectively according to step B3.1. Use an inductively coupled plasma mass spectrometer to detect the soluble lithium solution of the filter residue. According to the standard curve, the lithium concentrations of the solutions are 0.1014 μg / ml, 0.0998 μg / ml, and 0.1025 μg / ml respectively. Take the average value of the three concentrations, 0.1012 μg / ml, and record it as the soluble lithium content of the filter residue, and save the data.

[0043] Other parts of this embodiment are the same as those of Embodiment 6, so they will not be described in detail.

[0044] Embodiment 9: Based on Embodiments 7 and 8, this embodiment describes the specific operation of measuring the acidification rate in step B4. The specific process is as follows: Substitute the lithium element content of 3.4297 μg / ml of the clinker obtained in Embodiment 7 and the soluble lithium content of 0.1012 μg / ml of the filter residue obtained in Embodiment 8 into the acidification rate , and obtain the acidification rate η = 97.13%, and save the data.

[0045] Other parts of this embodiment are the same as those of Embodiments 7 and 8, so they will not be described in detail.

[0046] Embodiment 10: This embodiment provides a method for analyzing the conversion rate and acidification rate of lithium ore. By measuring the conversion rate and acidification rate data, analyze and judge the operation conditions of the conversion roasting process and the acidification roasting process, as Figure 3 shown, including the following steps: Step S1: Set the conversion rate threshold and acidification rate threshold that meet the requirements of reaching the standard and achieving full production in the sulfuric acid method for extracting lithium from ore; Step S2: Periodically extract the roasted materials produced in the conversion roasting process as measurement samples and measure the conversion rate; Step S3: Periodically extract the clinker produced in the acidification roasting process as a measurement sample, and measure the acidification rate; Step S4: Compare the data and analyze and judge whether it is necessary to prompt an abnormality or give an early warning.

[0047] In this embodiment, a conversion rate threshold α TH = 96.5% is set, and an acidification rate threshold η TH = 96.5% is set; at the same time, a measurement sample is extracted every 6 calendar days to measure the conversion rate and acidification rate: Table 1 Conversion rate and acidification rate measured four times continuously As shown in Table 1, on July 6, July 12, July 18, and July 24, the measured conversion rates were 97.45%, 97.25%, 97.13%, and 97.15% respectively, and the measured acidification rates were 97.13%, 97.08%, 97.11%, and 97.10%: Step S4 specifically includes Step S4.1 and Step S4.2; In Step S4.1, compare the measured conversion rate and acidification rate with the conversion rate threshold and acidification rate threshold respectively, and judge whether the operation conditions of the conversion roasting process and the acidification roasting process are abnormal: On July 6, July 12, July 18, and July 24, both the measured conversion rate and acidification rate are greater than the set conversion rate threshold α TH and acidification rate threshold η TH , indicating that the operation conditions of the conversion roasting process and the acidification roasting process during this period can meet the actual production requirements and there is no abnormality; In Step S4.2, compare the continuously measured conversion rate and acidification rate data, and judge whether to give an early warning for the operation conditions of the conversion roasting process and the acidification roasting process: Among July 6, July 12, July 18, and July 24, the working conditions of a decrease of more than 1.0% did not appear in any two consecutive measurement results, and the four consecutive measurement results did not show a continuous decrease, indicating that there is no continuous deterioration trend in the operation conditions of the conversion roasting process and the acidification roasting process during this period, and no early warning is required.

[0048] In Step S2 of this embodiment, preferably one of the methods for measuring the conversion rate of lithium ore in Embodiments 1-5 is used to measure the conversion rate; in Step S3, preferably one of the methods for measuring the acidification rate of lithium ore in Embodiments 6-9 is used to measure the acidification rate.

[0049] Without conflict, the above-mentioned embodiments and the features in the embodiments in this article can be combined with each other.

[0050] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A method for determining the transformation rate of lithium ore, characterized in that: The following steps are involved: Step A1, preparing a lithium standard solution and drawing a standard curve; Step A2, detecting the total lithium content of the roasted material produced in the transition roasting process, specifically comprising steps A2.1 and A2.2; Step A2.1, preparing a roasted material full lithium solution: Take 10g of roasted material produced by the transformation roasting process in the production process of lithium extraction by sulfuric acid method using spodumene as raw material as a roasted material sample, dry the roasted material sample at 105°C-110°C for 2 hours, and grind it into 200 mesh after cooling; Weigh 0.1500 g of the ground roasted sample, place it in a polytetrafluoroethylene crucible, moisten it with pure water, add 20 ml of hydrofluoric acid, and gently shake the crucible to mix; Place the crucible in a sand bath at 150-200°C and heat and evaporate until the roasted sample is in the form of wet salt; After the crucible is taken out and cooled to room temperature, 2 ml (1+1) sulfuric acid is added, and it is stirred lightly with a glass rod, and then 20 ml of pure water is added; Place the crucible in a 150°C sand bath and heat until the roasted sample is completely dissolved; After taking out the crucible and cooling it to room temperature, transfer the solution in the crucible to a 250ml volumetric flask, add water to dilute to the 250ml volumetric flask mark, shake well, let stand for 15 minutes, and filter; Take 10ml of the filtrate and put it into a 100ml volumetric flask, add 2ml (1+1) sulfuric acid, dilute with water to the 100ml volumetric flask mark, shake well, and obtain a full lithium solution of the roasted material; Step A2.2: Measure the concentration of the roasted material full lithium solution: Prepare three batches of roasted material full lithium solutions according to step A2.1, and use inductively coupled plasma mass spectrometry to detect the three batches of roasted material full lithium solutions. According to the standard curve, the lithium concentrations of the solutions are T1Li2Oμg / ml, T2Li2Oμg / ml, and T3Li2Oμg / ml, respectively. Take the average value of the three concentrations, TLi2Oμg / ml, and record it as the roasted material full lithium content, and save the data; Step A3, detecting the soluble lithium content of the roasted material produced in the transition roasting process; Step A4, determining the transformation rate.

2. The method for determining the lithium ore transformation rate according to claim 1, characterized in that: The specific process of preparing the lithium element standard solution and drawing the standard curve in step A1 is as follows: Take 20g lithium carbonate sample and place it in a vacuum drying oven and dry it at 105℃ for 2 hours; After cooling for 30 minutes, weigh 2.4729g of lithium carbonate sample using an analytical balance, place it in a 100ml beaker, add 30ml of water, and then drop 10ml of (1+1) sulfuric acid solution to dissolve the lithium carbonate sample; Heat the dissolved lithium carbonate sample to boiling with a universal electric furnace to eliminate CO2. After cooling for 30 minutes, transfer the solution in the beaker to a 1000ml volumetric flask and add water to dilute to the 1000ml volumetric flask mark to obtain a 1000μg / ml lithium standard solution. The lithium standard solution is calculated as Li2O. Take 1000μg / ml lithium standard solution, and prepare a series of lithium standard solutions by stepwise dilution method: the concentrations are 0μg / ml, 1μg / ml, 2μg / ml, 3μg / ml, 4μg / ml, 5μg / ml, and 6μg / ml. Use inductively coupled plasma mass spectrometry to detect the series of lithium standard solutions, and draw a standard curve based on the relationship between the test results and concentrations.

3. The method for determining the lithium ore transformation rate according to claim 1, characterized in that: The specific process of step A3 for detecting the soluble lithium content of the roasted material produced in the transition roasting process includes step A3.1 and step A3.2: Step A3.1, preparing a soluble lithium solution of roasted material: Take 10g of roasted material produced by the transformation roasting process in the production process of lithium extraction by sulfuric acid method using spodumene as raw material as a roasted material sample, dry the roasted material sample at 105°C-110°C for 2 hours, and grind it into 200 mesh after cooling; Weigh 0.1500 g of the ground roasted sample and place it in a ceramic crucible. Add 3.5 ml (4+1) sulfuric acid and gently shake the crucible to mix. The crucible was covered with a ceramic cover and placed in a muffle furnace, heated to 260°C and kept at this temperature for 30 minutes; After taking out the crucible and cooling it to room temperature, transfer the solution in the crucible to a 250ml volumetric flask, add water to dilute to the 250ml volumetric flask mark, shake well, let stand for 15 minutes, and filter; Take 10 ml of the filtrate, put it into a 100 ml volumetric flask, add 2 ml of (1+1) sulfuric acid, add water to the 100 ml volumetric flask mark, shake well, and obtain a soluble lithium solution of the roasted material; Step A3.2, measuring the concentration of the soluble lithium solution of the roasted material: From the same batch of roasted material samples, three roasted material soluble lithium solutions were prepared according to step A3.1, and the three roasted material soluble lithium solutions were detected using an inductively coupled plasma mass spectrometer. According to the standard curve, the lithium concentrations of the solutions were obtained as β1Li2Oμg / ml, β2Li2Oμg / ml, and β3Li2Oμg / ml, respectively. The average value of the three concentrations, βLi2Oμg / ml, was taken as the roasted material soluble lithium content, and the data was saved.

4. The method for determining the lithium ore transformation rate according to claim 3, characterized in that: The specific process of determining the transformation rate in step A4 is as follows: Substitute the total lithium content TLi20 μg / ml of the roasted material obtained in step A2 and the soluble lithium content βLi20 μg / ml of the roasted material obtained in step A3 into the transformation rate , find the transformation rate α and save the data.

5. A method for determining the acidification rate of lithium ore, characterized in that: The following steps are involved: Step B1, preparing a lithium standard solution and drawing a standard curve; Step B2, detecting the lithium content of the clinker produced in the acidification roasting step, specifically comprising steps B2.1 and B2.2; Step B2.1, preparing clinker solution: Take 10g of clinker produced by the acidification and roasting process in the production process of lithium extraction by sulfuric acid method using spodumene as raw material as the clinker sample, weigh 0.2000g of the clinker sample and place it in a 250ml beaker, and add 50ml of pure water; Place a magnetic stirring bar in the beaker, cover it with a glass slide, place the beaker in the middle of the stirrer, and stir for 20 minutes; Add 5 ml (1+1) sulfuric acid, stir evenly, transfer to a 250 ml volumetric flask, add water to dilute to the 250 ml volumetric flask mark, shake well, let stand for 15 minutes, filter, and obtain the filtrate and residue; Take 10 ml of the filtrate, put it into a 100 ml volumetric flask, add 2 ml (1+1) sulfuric acid, dilute with water to the 100 ml volumetric flask mark, shake well, and let it stand for 15 minutes to obtain a clinker solution; Step B2.2, measuring the concentration of the clinker solution: Three clinker solutions were prepared from the same batch of clinker samples according to step B2.

1. The three clinker solutions were tested using an inductively coupled plasma mass spectrometer. The lithium concentrations of the solutions were S1Li2Oμg / ml, S2Li2Oμg / ml, and S3Li2Oμg / ml, respectively, according to the standard curve. The average value of the three concentrations, SLi2Oμg / ml, was taken as the lithium content of the clinker and the data was saved. Step B3, detecting the soluble lithium content of the filter residue produced in step B2: Step B3.1, preparing a residue soluble lithium solution: The filter residue produced in step B2 is dried at 105°C-110°C for 2 hours, and after cooling, is ground into 200 mesh; Weigh the ground filter residue and place it in a ceramic crucible. Add 3.5 ml (4+1) sulfuric acid and gently shake the crucible to mix. The crucible was covered with a ceramic cover and placed in a muffle furnace, heated to 260°C and kept at this temperature for 30 minutes; After taking out the crucible and cooling it to room temperature, transfer the solution in the crucible to a 250ml volumetric flask, add water to dilute to the 250ml volumetric flask mark, shake well, let stand for 15 minutes, and filter; Take 10 ml of the filtrate, put it into a 100 ml volumetric flask, add 2 ml (1+1) sulfuric acid, add water to the 100 ml volumetric flask mark, shake well, and obtain a soluble lithium solution of the filter residue; Step B3.2, measuring the concentration of the soluble lithium solution in the filter residue: Three portions of filter residue are produced in step B2, and filter residue soluble lithium solutions are prepared respectively according to step B3.

1. The filter residue soluble lithium solutions are detected by inductively coupled plasma mass spectrometry, and the lithium concentrations of the solutions ST1Li2Oμg / ml, ST2Li2Oμg / ml, and ST3Li2Oμg / ml are obtained according to the standard curve. The average value of the three concentrations STLi2Oμg / ml is taken and recorded as the soluble lithium content of the clinker, and the data is saved; Step B4, determining the acidification rate.

6. The method for determining the acidification rate of lithium ore according to claim 5, characterized in that: The specific process of determining the acidification rate in step B4 is as follows: Substitute the lithium content SLi20 μg / ml of the clinker obtained in step B2 and the soluble lithium content STLi20 μg / ml of the clinker obtained in step B3 into the acidification rate , calculate the acidification rate η and save the data.

7. A method for analyzing the transformation rate and acidification rate of lithium ore, characterized in that: By measuring and analyzing the transformation rate and acidification rate data, the operation status of the transformation roasting process and the acidification roasting process is judged, including the following steps: Step S1, setting a transformation rate threshold and an acidification rate threshold that meet the production requirements of lithium extraction from ore by sulfuric acid method; Step S2, regularly extracting roasted materials produced in the transformation roasting process as roasted material samples, and determining the transformation rate; Step S3, regularly extracting clinker produced in the acidification and roasting process as clinker samples, and determining the acidification rate; Step S4, comparing the data, analyzing and determining whether an abnormality prompt and / or warning is required; In the step S2, the transformation rate is determined by the method for determining the transformation rate of lithium ore as described in any one of claims 1 to 4; in the step S3, the acidification rate is determined by the method for determining the acidification rate of lithium ore as described in claim 5 or 6.

8. The method for analyzing lithium ore transformation rate and acidification rate according to claim 7, characterized in that: The step S4 specifically refers to comparing the measured transformation rate with the transformation rate threshold, comparing the measured acidification rate with the acidification rate threshold, and analyzing and judging whether the operation of the transformation roasting process and the acidification roasting process is abnormal: When the measured transformation rate is less than the transformation rate threshold, it indicates that the transformation roasting process is operating abnormally; When the measured acidification rate is less than the acidification rate threshold, it indicates that the acidification roasting process is operating abnormally.

9. The method for analyzing lithium ore transformation rate and acidification rate according to claim 7, characterized in that: The step S4 specifically refers to comparing the continuously measured transformation rate and the continuously measured acidification rate data to determine whether to issue an early warning for the operation of the transformation roasting process and the acidification roasting process: When the transformation rate measured twice in a row drops by more than 1.0%, or the transformation rate measured four times in a row drops, an early warning is issued; When the acidification rate measured twice in a row drops by more than 1.0%, or the acidification rate measured four times in a row drops, an early warning will be issued.

10. The method for analyzing lithium ore transformation rate and acidification rate according to claim 7, characterized in that: The frequency of regularly extracting measurement samples in step S2 and step S3 is once every 6 calendar days.

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