Method for calculating dosage of impurity removing agent during extraction of rare earth leachate by carbonate precipitation method
By calculating the amount of impurity removal agent consumed by the precipitation and hydrolysis of each ions in the rare earth leaching solution, the problem of lack of standards for impurity removal in the prior art is solved, and efficient impurity removal effect and low rare earth loss rate are achieved.
Patent Information
- Application Number
- CN202510054739.9
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-14
- Publication Date
- 2025-04-25
AI Technical Summary
The prior art lacks a standardized calculation method for the amount of impurity removal agents in the carbonate precipitation method of rare earth leaching liquid, resulting in excessive amounts and resource losses.
By obtaining the concentrations of aluminum ions, iron ions, rare earth ions, ammonium ions and hydrogen ions in the rare earth leaching liquid, the amount of impurity removal agent consumed by precipitation and hydrolysis of each ions in the impurity removal process is calculated separately, and the total impurity removal agent consumption is accumulated.
The amount of impurity removal is reasonably determined. The error between the test results and the target pH value is within 2%, the impurity removal rate is greater than 97.5%, and the rare earth loss rate is less than 2%.
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Figure CN119889486A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of rare earth metallurgy, and in particular relates to a method for calculating the amount of an impurity remover used in extracting rare earth leaching solution by carbonate precipitation method. Background Art
[0002] Ionic rare earth ores are chemically leached to obtain mother liquor containing rare earth ions. This mother liquor has problems such as high impurity content and low rare earth element concentration. It cannot be directly smelted and separated, so it needs to be treated accordingly. At present, the conventional treatment methods mainly include extraction and precipitation. The extraction method is still in the industrial trial stage due to its high cost and problems such as organic pollution in the raffinate. The method used in industrial sites is conventionally carbonate precipitation.
[0003] Currently, there is no industry standard for the process of enriching leachate by precipitation. The endpoint of the process is determined by the pH post-evaluation method. If the dosage is excessive, it will cause irreversible resource loss. Summary of the invention
[0004] The purpose of the present invention is to provide a method for calculating the amount of impurity remover used in the extraction of rare earth leaching solution by carbonate precipitation method, which can reasonably determine the amount of impurity remover used.
[0005] In order to solve the above technical problems, the technical solution of the present invention is: a method for calculating the amount of impurity remover used in the extraction of rare earth leaching solution by carbonate precipitation method, comprising the following steps:
[0006] Obtaining the concentrations of aluminum ions, iron ions, rare earth ions, ammonium ions and hydrogen ions in the rare earth leaching solution;
[0007] Calculate the amount of impurity remover consumed by aluminum ion precipitation, iron ion precipitation, ammonium ion hydrolysis and pH change in the rare earth leaching solution during the carbonate precipitation impurity removal process.
[0008] The total impurity remover dosage was obtained by adding up the dosages of each impurity remover.
[0009] The carbonate precipitation method includes an impurity removal process and a precipitation process; wherein, the impurity removal process is specifically as follows: the pH value of the rare earth leaching solution is adjusted to 5.2 by adding carbonate, so that aluminum ions and iron ions are precipitated to obtain a supernatant; the precipitation process is specifically as follows: the supernatant generates rare earth carbonate precipitate under the action of a new round of added carbonate to obtain a rare earth product.
[0010] Reactions in the impurity removal process include:
[0011] 1) Iron ion Fe 3+ Precipitation: In the impurity removal process, Fe 3+ will be precipitated, consuming the OH provided by the bicarbonate ions - , the reaction equation (1) is expressed as:
[0012]
[0013] in, is the solubility product constant of ferric hydroxide;
[0014] 2) Calcium ion Ca 2+ Precipitation: Calcium ions in rare earth leaching solution undergo two types of precipitation, namely calcium sulfate precipitation and calcium carbonate precipitation, which can be expressed by reaction equation (2):
[0015]
[0016] in, is the solubility product constant of calcium sulfate, is the solubility product constant of calcium carbonate;
[0017] From equations (2) and (3), it can be seen that the conditions for calcium ion precipitation are:
[0018]
[0019] in, is the carbonate ion concentration in the rare earth leaching solution, is the sulfate ion concentration in the rare earth leaching solution, and its unit is mol / L. From formula (4), it can be seen that the carbonate ion concentration must reach 8.8*10 -4 mol / L, which cannot be achieved during precipitation reaction, so calcium ion precipitation is not considered;
[0020] 3)Rare earth ions RE 3+ Precipitation: Rare earth ions undergo two types of precipitation during the impurity removal process, namely rare earth hydroxide precipitation and rare earth carbonate precipitation, which are expressed by reaction equations (5) and (6):
[0021]
[0022] 4) Aluminum ion Al 3+ Precipitation: Aluminum ions produce aluminum hydroxide precipitation during the impurity removal process. When the aluminum ions are completely precipitated, the pH value is 5.2, and the hydrogen ion concentration is 10 -5.2 , the hydroxide ion concentration is 10 -8.8 , the reaction equation (7) is expressed as:
[0023]
[0024] in, is the solubility product constant of aluminum hydroxide;
[0025] 5) H +Source: Hydrogen ion consumption comes from the hydrolysis of bicarbonate ions and the dissociation of water, which can be expressed by reaction equations (8) to (10):
[0026]
[0027] Among them, k w is the ionic product constant of water;
[0028] 6) Ammonium ion NH 4 + Hydrolysis of ammonium ions: ammonium ions are acidic cations, and the removal process is accompanied by changes in pH, which causes NH 4 + The hydrolysis of is expressed by reaction equation (11):
[0029]
[0030] in, is the hydrolysis constant of ammonium ion.
[0031] The calculation method of the amount of impurity remover for aluminum ion precipitation is as follows:
[0032] According to reaction equations (7) and (8), the amount of impurity remover M for aluminum ion precipitation is obtained by the law of charge conservation: 除杂剂-Al It is expressed as:
[0033]
[0034] Among them, M r(除杂剂) is the relative molecular weight of the impurity remover, is the concentration of aluminum ions in the rare earth leaching solution; pH * is the pH value of the solution at the end point of the reaction.
[0035] The calculation method of the amount of impurity remover for iron ion precipitation is as follows:
[0036] According to reaction equation (1) and equation (8), the amount of impurity remover M for iron ion precipitation is obtained by the law of charge conservation: 除杂剂-Fe It is expressed as:
[0037]
[0038] in, is the concentration of iron ions in the rare earth leaching solution.
[0039] The specific method for calculating the amount of impurity remover consumed by ammonium ion hydrolysis is:
[0040] According to reaction equations (8) and (11), the amount of impurity remover consumed by ammonium ion hydrolysis is obtained by the law of charge conservation: 除杂剂-NH It is expressed as:
[0041]
[0042] in, pH 0 is the initial pH value of the supernatant.
[0043] The specific method for calculating the amount of impurity remover consumed by pH change is:
[0044] According to reaction equations (8) and (9), the amount of impurity remover consumed by pH change is obtained by the law of charge conservation: 除杂剂-H It is expressed as:
[0045]
[0046] The total impurity remover dosage is expressed as:
[0047] M 除杂剂-总 =M 除杂剂-Al +M 除杂剂-Fe +M 除杂剂-NH +M 除杂剂-H (11)
[0048] Among them, M 除杂剂-总 is the total amount of impurity remover used.
[0049] A computer device is also provided, comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor implements the steps of any of the above methods when executing the computer program.
[0050] A computer-readable storage medium is also provided, on which a computer program is stored, and when the computer program is executed by a processor, the steps of any of the above methods are implemented.
[0051] Compared with the prior art, the present invention has the following beneficial effects:
[0052] The present invention comprehensively considers the reaction process of each ion in the rare earth leaching solution in the impurity removal process, makes full use of the concentration product theory and the hydrolysis theory, and proposes a theoretical calculation method for the amount of impurity remover when the rare earth leaching solution is enriched by the carbonate precipitation method, which provides a theoretical basis for reasonably determining the amount of impurity remover. The amount of impurity remover determined by the present invention is scientific and reasonable, the error between the test result and the target pH value is within 2%, the impurity removal rate is greater than 97.5%, and the rare earth loss rate is less than 2%. BRIEF DESCRIPTION OF THE DRAWINGS
[0053] Figure 1 Schematic diagram of a flow chart of an embodiment of the present invention. DETAILED DESCRIPTION
[0054] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0055] The technical solution of the present invention is: a method for calculating the amount of impurity remover used in the carbonate precipitation extraction of rare earth leaching solution, such as Figure 1 As shown, the following steps are included:
[0056] Obtaining the concentrations of aluminum ions, iron ions, rare earth ions, ammonium ions and hydrogen ions in the rare earth leaching solution;
[0057] Calculate the amount of impurity remover consumed by aluminum ion precipitation, rare earth ion precipitation, ammonium ion hydrolysis and pH change in the rare earth leaching solution in the carbonate precipitation impurity removal process, the unit is kg / m 3 ;
[0058] The total impurity remover dosage was obtained by adding up the dosages of each impurity remover.
[0059] The carbonate precipitation method includes an impurity removal process and a precipitation process; wherein, the impurity removal process is specifically as follows: the pH value of the rare earth leaching solution is adjusted to 5.2 by adding carbonate, so that aluminum ions and iron ions are precipitated to obtain a supernatant; the precipitation process is specifically as follows: the supernatant generates rare earth carbonate precipitate under the action of a new round of added carbonate to obtain a rare earth product.
[0060] Reactions in the impurity removal process include:
[0061] 1) Iron ion Fe 3+ Precipitation: In the impurity removal process, Fe 3+ will be precipitated, consuming the OH provided by the bicarbonate ions - , the reaction equation (1) is expressed as:
[0062]
[0063] in, is the solubility product constant of ferric hydroxide;
[0064] 2) Calcium ion Ca 2+ Precipitation: Calcium ions in rare earth leaching solution undergo two types of precipitation, namely calcium sulfate precipitation and calcium carbonate precipitation, which can be expressed by reaction equation (2):
[0065]
[0066] in, is the solubility product constant of calcium sulfate, is the solubility product constant of calcium carbonate;
[0067] From equations (2) and (3), it can be seen that the conditions for calcium ion precipitation are:
[0068]
[0069] in, is the carbonate ion concentration in the rare earth leaching solution, is the sulfate ion concentration in the rare earth leaching solution, and its unit is mol / L. From formula (4), it can be seen that the carbonate ion concentration must reach 8.8*10 -4 mol / L, which cannot be achieved during precipitation reaction, so calcium ion precipitation is not considered;
[0070] 3)Rare earth ions RE 3+ Precipitation: Rare earth ions undergo two types of precipitation during the impurity removal process, namely rare earth hydroxide precipitation and rare earth carbonate precipitation, which are expressed by reaction equations (5) and (6):
[0071]
[0072] According to the previous research results, it is mainly carried out in the form of rare earth carbonate, that is, according to formula (5).
[0073] 4) Aluminum ion Al 3+ Precipitation: Aluminum ions precipitate aluminum hydroxide during the impurity removal process, and the aluminum ions are completely precipitated (10 -6 mol / L), the pH value is 5.2, at which time the hydrogen ion concentration is 10 -5.2 , the hydroxide ion concentration is 10 -8.8 , the reaction equation (7) is expressed as:
[0074]
[0075] in, is the solubility product constant of aluminum hydroxide;
[0076] 5) H + (OH - ) Source: Hydrogen ion consumption (hydroxyl ion production) comes from the hydrolysis of bicarbonate ions and the dissociation of water, which can be expressed by reaction equations (8) to (10):
[0077]
[0078]
[0079] Among them, k w is the ionic product constant of water;
[0080] 6) Ammonium ion NH 4 + Hydrolysis of ammonium ions: ammonium ions are acidic cations, and the removal process is accompanied by changes in pH, which causes NH 4 + The hydrolysis of is expressed by reaction equation (11):
[0081]
[0082] in, is the hydrolysis constant of ammonium ion.
[0083] As can be seen from the above, the overall reaction in the impurity removal stage includes: aluminum ion precipitation to produce aluminum hydroxide; iron ion precipitation to produce iron hydroxide; ammonium ion hydrolysis in the solution; pH change (hydrogen ion-hydroxyl ion) concentration change. Therefore, according to the above chemical reaction process, the theoretical calculation of the amount of impurity remover can be carried out under the condition of a given endpoint pH. It can provide a theoretical basis and technical guidance for the subsequent automation of rare earth mother liquor treatment by carbonate precipitation method.
[0084] The calculation method of the amount of impurity remover for aluminum ion precipitation is as follows:
[0085] According to reaction equations (7) and (8), the amount of impurity remover M for aluminum ion precipitation is obtained by the law of charge conservation: 除杂剂-Al It is expressed as:
[0086]
[0087] Among them, M r(除杂剂) is the relative molecular weight of the impurity remover, ammonium bicarbonate is 79, sodium bicarbonate is 84; is the concentration of aluminum ions in the rare earth leaching solution; pH * is the pH value of the solution at the end point of the reaction.
[0088] The calculation method of the amount of impurity remover for iron ion precipitation is as follows:
[0089] According to reaction equation (1) and equation (8), the amount of impurity remover M for iron ion precipitation is obtained by the law of charge conservation: 除杂剂-Fe It is expressed as:
[0090]
[0091] in, is the concentration of iron ions in the rare earth leaching solution.
[0092] The specific method for calculating the amount of impurity remover consumed by ammonium ion hydrolysis is:
[0093] According to reaction equations (8) and (11), the amount of impurity remover consumed by ammonium ion hydrolysis is obtained by the law of charge conservation: 除杂剂-NH It is expressed as:
[0094]
[0095] in, pH 0 is the initial pH value of the supernatant.
[0096] The specific method for calculating the amount of impurity remover consumed by pH change is:
[0097] According to reaction equations (8) and (9), the amount of impurity remover consumed by pH change is obtained by the law of charge conservation: 除杂剂-H It is expressed as:
[0098]
[0099] The total impurity remover dosage is expressed as:
[0100] M 除杂剂-总 =M 除杂剂-Al +M 除杂剂-Fe +M 除杂剂-NH +M 除杂剂-H (11)
[0101] Among them, M 除杂剂-总 is the total amount of impurity remover used.
[0102] In the present embodiment, the ion content of three leachates with different properties was tested, and the results are shown in Table 1:
[0103] Table 1
[0104]
[0105] Ammonium bicarbonate and sodium bicarbonate were used as impurity removers respectively, and the pH was 5.2 as the end point pH. The dosage of impurity removers was calculated and the dosage table of impurity removers was shown in Table 2. The units of each parameter in the table are kg / m 3 :
[0106] Table 2
[0107]
[0108] According to M in Table 2 除杂剂-总 The impurity removal experiment was carried out on the leaching solution with the dosage of and the results are shown in Table 3:
[0109] Table 3
[0110]
[0111]
[0112] As can be seen from the table above, according to the theoretical calculation of the impurity remover dosage of the present invention, the error between the test result and the target pH value is within 2%, the impurity removal rate is greater than 97.5%, and the rare earth loss rate is less than 2%, indicating that the impurity remover dosage determined by this method is scientific and reasonable.
[0113] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.
Claims
1. A method for calculating the amount of impurity remover used in the extraction of rare earth leaching solution by carbonate precipitation method, characterized in that: The following steps are involved: Obtaining the concentrations of aluminum ions, iron ions, rare earth ions, ammonium ions and hydrogen ions in the rare earth leaching solution; Calculate the amount of impurity remover consumed by aluminum ion precipitation, iron ion precipitation, ammonium ion hydrolysis and pH change in the rare earth leaching solution during the carbonate precipitation impurity removal process. The total impurity remover dosage was obtained by adding up the dosages of each impurity remover.
2. The method for calculating the amount of impurity remover used in the carbonate precipitation extraction of rare earth leachate according to claim 1, characterized in that: The carbonate precipitation method includes an impurity removal process and a precipitation process; wherein the impurity removal process is specifically as follows: the pH of the rare earth leaching solution is adjusted to 5.2 by adding carbonate, so that aluminum ions and iron ions are precipitated to obtain a supernatant.
3. The method for calculating the amount of impurity remover used in the carbonate precipitation extraction of rare earth leachate according to claim 2, characterized in that: Reactions in the impurity removal process include: 1) Iron ion Fe 3+ Precipitation: In the impurity removal process, Fe 3+ will be precipitated, consuming the OH provided by the bicarbonate ions - , the reaction equation (1) is expressed as: in, is the solubility product constant of ferric hydroxide; 2) Calcium ion Ca 2+ Precipitation: Calcium ions in rare earth leaching solution undergo two types of precipitation, namely calcium sulfate precipitation and calcium carbonate precipitation, which can be expressed by reaction equation (2): in, is the solubility product constant of calcium sulfate, is the solubility product constant of calcium carbonate; From equations (2) and (3), it can be seen that the conditions for calcium ion precipitation are: in, is the carbonate ion concentration in the rare earth leaching solution, is the sulfate ion concentration in the rare earth leaching solution, and its unit is mol / L. From formula (4), it can be seen that the carbonate ion concentration must reach 8.8*10 -4 mol / L, which cannot be achieved during precipitation reaction, so calcium ion precipitation is not considered; 3)Rare earth ions RE 3+ Precipitation: Rare earth ions undergo two types of precipitation during the impurity removal process, namely rare earth hydroxide precipitation and rare earth carbonate precipitation, which are expressed by reaction equations (5) and (6): 4) Aluminum ion Al 3+ Precipitation: Aluminum ions produce aluminum hydroxide precipitation during the impurity removal process. When the aluminum ions are completely precipitated, the pH value is 5.2, and the hydrogen ion concentration is 10 -5.2 , the hydroxide ion concentration is 10 -8.8 , the reaction equation (7) is expressed as: in, is the solubility product constant of aluminum hydroxide; 5) H + Source: Hydrogen ion consumption comes from the hydrolysis of bicarbonate ions and the dissociation of water, which can be expressed by reaction equations (8) to (10): Among them, k w is the ionic product constant of water; 6) Ammonium ion NH4 + Hydrolysis: Ammonium ion is an acidic cation, and the impurity removal process is accompanied by changes in pH, which causes NH4 + The hydrolysis of is expressed by reaction equation (11): in, is the hydrolysis constant of ammonium ion.
4. The method for calculating the amount of impurity remover used in the carbonate precipitation extraction of rare earth leaching solution according to claim 3, characterized in that: The calculation method of the amount of impurity remover for aluminum ion precipitation is as follows: According to reaction equations (7) and (8), the amount of impurity remover M for aluminum ion precipitation is obtained by the law of charge conservation: 除杂剂-Al It is expressed as: Among them, M r(除杂剂) is the relative molecular weight of the impurity remover, is the concentration of aluminum ions in the rare earth leaching solution; pH * is the pH value of the solution at the end point of the reaction.
5. The method for calculating the amount of impurity remover used in the carbonate precipitation extraction of rare earth leachate according to claim 4, characterized in that: The calculation method of the amount of impurity remover for iron ion precipitation is as follows: According to reaction equation (1) and equation (8), the amount of impurity remover M for iron ion precipitation is obtained by the law of charge conservation: 除杂剂-Fe It is expressed as: in, is the concentration of iron ions in the rare earth leaching solution.
6. The method for calculating the amount of impurity remover used in the carbonate precipitation extraction of rare earth leaching solution according to claim 5, characterized in that: The specific method for calculating the amount of impurity remover consumed by ammonium ion hydrolysis is: According to reaction equations (8) and (11), the amount of impurity remover consumed by ammonium ion hydrolysis is obtained by the law of charge conservation: 除杂剂-NH It is expressed as: in, pH 0 is the initial pH value of the supernatant.
7. The method for calculating the amount of impurity remover used in the carbonate precipitation extraction of rare earth leaching solution according to claim 6, characterized in that: The specific method for calculating the amount of impurity remover consumed by pH change is: According to reaction equations (8) and (9), the amount of impurity remover consumed by pH change is obtained by the law of charge conservation: 除杂剂-H It is expressed as:
8. The method for calculating the amount of impurity remover used in the carbonate precipitation extraction of rare earth leaching solution according to claim 7, characterized in that: The total impurity remover dosage is expressed as: M 除杂剂-总 =M 除杂剂-Al +M 除杂剂-Fe +M 除杂剂-NH +M 除杂剂-H (11) Among them, M 除杂剂-总 is the total amount of impurity remover used.
9. A computer device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that: When the processor executes the computer program, the steps of the method according to any one of claims 1 to 8 are implemented.
10. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 8 are implemented.