Method for accurately regulating and controlling pH by adding sodium carbonate in flotation process of tungsten flotation tailings

Abstract

The invention belongs to the technical field of pH regulation and control of tungsten separation tailings flotation wolframite and scheelite, particularly relates to a method for accurately regulating and controlling pH by adding sodium carbonate in the tungsten separation tailings flotation process, and is suitable for accurately regulating and controlling the pH of ore pulp when wolframite and scheelite are recycled from tungsten separation tailings in a flotation mode. According to the method, a calibration fitting relation curve and a fitting relation curve formula of sodium carbonate mass-volume percentage concentration and hydroxyl ion concentration in ore pulp are established, and the use amount of sodium carbonate and the use amount of an aqueous solution of sodium carbonate are accurately calculated according to parameters such as the mass of actual tungsten separation tailings and the ore pulp concentration in combination with a regulated target pH value; according to the method, efficient and accurate regulation and control of the pH value of the ore pulp are achieved, the problems that a conventional regulation and control method is slow in regulation process, lagged in result, low in accuracy and the like are solved, the accuracy and efficiency of pH regulation are remarkably improved, and meanwhile the reagent consumption and equipment corrosion risks are reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of pH control in the flotation of wolframite and scheelite from tungsten tailings, and in particular relates to a method for accurately controlling the pH by adding sodium carbonate during the flotation process of tungsten tailings. Background Art

[0002] The flotation of wolframite and scheelite often operates in an alkaline environment, and conventionally, sodium hydroxide, lime, sodium carbonate, and sodium silicate are used to control the pH of the slurry. Sodium hydroxide has a rapid pH adjustment rate, with a pH range of up to 14, making it suitable for applications requiring rapid adjustment to a higher pH. However, it is costly and requires high corrosion resistance from the equipment, making it generally suitable for laboratory testing and uncommon in industrial settings. Sodium carbonate, a salt of a strong base and a weak acid, has an adjustable pH range of 7 to 12 and a strong buffering capacity. The carbonate ions can remove metal cations from the slurry with minimal effect on slurry viscosity, making it suitable for flotation systems sensitive to metal cations. Sodium silicate, a salt of a strong base and a weak acid, acts as a suppressant for gangue minerals and a dispersant for the slurry. The ions produced by the hydrolysis of sodium silicate adsorb on the surface of the silicate gangue, forming a hydrophilic film that inhibits the binding of the gangue to the collector and effectively improves flotation performance.

[0003] The principle of conventional pH control is to prepare an aqueous solution of an alkali-adjusting agent (such as lime, sodium carbonate, etc.) at a certain mass volume percentage concentration (e.g., 1%, 2%), add this solution to the roughing section of the flotation process, and use a pH meter or advanced online pH meter to test and record the pH value. If the pH value is too high, reduce the amount of the alkali-adjusting agent added; if the pH value is too low, increase the amount of the alkali-adjusting agent added until the target pH is reached. The pH value is then monitored regularly, and if there is any deviation from the target pH value, the same control procedure is repeated. If pH control is required in the cleaning or scavenging sections, the control steps are similar to those in the roughing section.

[0004] When wolframite and scheelite are recovered from tungsten tailings by flotation, there are many dissolved metal cations in the pulp, such as iron ions (Fe 2+ 、Fe 3+ ), copper ions (Cu 2+ ), calcium ions (Ca 2+ ), magnesium ions (Mg 2+ ), etc. There are also many gangue minerals, such as hematite, sphalerite, chalcopyrite, pyrite, kaolinite, calcite, dolomite, quartz, etc. After adding the alkali adjusting agent, the metal cations and gangue mineral particles will absorb the anions dissociated by the alkali adjusting agent (such as CO3 2- ), and also adsorbs OH produced by hydrolysis or direct dissociation of the alkali adjusting agent - , this adsorption of anions (such as CO3 2- ) and OH- The behavior of the slurry often plays a buffering or weakening role in the increase of slurry pH. In fact, the metal cations and anions adsorbed by gangue mineral particles (such as CO3 2- ) and OH - The amount of pH cannot be accurately measured; it depends entirely on the properties of the tungsten tailings. Therefore, conventional pH control methods can only be implemented using a feedback mechanism. This involves adding an alkali-adjusting agent to the slurry and measuring the pH. If the pH is too high or too low, the amount of alkali-adjusting agent is then reduced or increased to adjust accordingly. Consequently, this conventional pH control method inevitably suffers from drawbacks such as a slow adjustment process, delayed results, and low accuracy. Summary of the Invention

[0005] In order to solve the above technical defects, the present invention provides a method for accurately controlling the pH value by adding sodium carbonate during the flotation process of tungsten tailings, which improves the accuracy and efficiency of controlling the pH value of the pulp by adding sodium carbonate during the flotation process of tungsten tailings, and can accurately and efficiently control the pH value.

[0006] A method for accurately controlling pH by adding sodium carbonate during the flotation process of tungsten tailings, comprising the following steps:

[0007] S1: Through experiments, establish the relationship between the mass volume percentage concentration of sodium carbonate and OH after adding sodium carbonate aqueous solution as an alkali adjustment agent to tungsten tailings with different concentrations. - Calibration fitting relationship curve of concentration;

[0008] S2: For the flotation pulp of a specific concentration, determine a target pH value to be achieved, select a calibration fitting relationship curve corresponding to the pulp concentration, and calculate the mass volume percentage concentration of sodium carbonate;

[0009] S3: Convert the mass volume percentage concentration of sodium carbonate into the amount of sodium carbonate used as the alkali adjusting agent and the amount of aqueous solution used.

[0010] Furthermore, step S1 specifically includes the following steps:

[0011] S1.1: Prepare tungsten tailings flotation slurry and sodium carbonate aqueous solution as alkali adjustment agent;

[0012] S1.2: In the flotation slurry of tungsten tailings, sodium carbonate aqueous solution is added to adjust the pH value of the slurry. The relationship between the amount of sodium carbonate aqueous solution used and the pH value of the slurry can be obtained; the amount of sodium carbonate aqueous solution is converted into the mass volume percentage concentration of sodium carbonate in the slurry, and the pH value is converted into the OH concentration of the slurry. - The relationship between the concentration of sodium carbonate solution and the pH value of the pulp can be converted into the mass volume percentage concentration of sodium carbonate and OH - Concentration relationship, establish relationship curve;

[0013] S1.3: Fitting the mass volume percentage concentration of sodium carbonate and OH - The concentration relationship curve is obtained, and the calibration fitting relationship curve and the fitting relationship curve formula are obtained. The horizontal axis X axis of the fitting curve is the mass volume percentage concentration of sodium carbonate, and the vertical axis Y axis is OH - concentration.

[0014] Furthermore, step S2 specifically includes the following steps:

[0015] S2.1: Determine and calculate the specific concentration of tungsten tailings flotation pulp;

[0016] S2.2: Select the calibration fitting relationship curve corresponding to the slurry concentration, determine the target pH value that needs to be adjusted, and convert the target pH value into the target OH - concentration, OH - Substitute the concentration into the fitting curve formula and call the calculate function in the Python 3.8 program to calculate the mass volume percentage concentration of sodium carbonate.

[0017] Furthermore, step S3 specifically includes the following steps:

[0018] S3.1: Calculate the dosage of sodium carbonate, an alkali adjustment agent, according to formula 1;

[0019] S3.2: Calculate the amount of sodium carbonate aqueous solution, an alkali adjustment agent, according to formula 2.

[0020] Furthermore, the slurry concentration in step S1.1 is in the range of 20-30%, and the mass volume percentage concentration of the sodium carbonate aqueous solution is in the range of 1-6%.

[0021] Furthermore, the method for determining and calculating the concentration of the tungsten tailings slurry in step S2.1 can be determined by using a concentration pot method or other methods at industrial sites, while it can be directly calculated in laboratory tests.

[0022] Furthermore, the formula 1 in step S3.1 is: , where: M T —Amount of sodium carbonate / g; C T —Sodium carbonate mass volume percentage concentration / %; M S —Mass of tungsten tailings / g; C S —Tungsten tailings slurry concentration / %, (Where: M L —Liquid mass of slurry / g).

[0023] Furthermore, formula 2 in step S3.2 is: , where: V T —Amount of sodium carbonate aqueous solution / ml; c T—Mass volume percentage concentration of sodium carbonate aqueous solution / %.

[0024] The beneficial effect is that the present invention establishes a calibration fitting relationship curve between the mass volume percentage concentration of sodium carbonate and the hydroxide ion concentration, and when recovering wolframite and scheelite by flotation from tungsten tailings, the target pH value achieved by regulation can be combined with the calibration fitting relationship curve and the fitting relationship curve formula, and the amount of sodium carbonate and the amount of aqueous solution can be accurately calculated according to the actual mass of the tungsten tailings and the slurry concentration and other parameters, thereby achieving efficient and precise regulation of the slurry pH value, solving the problems of slow regulation process, delayed results, and low accuracy existing in conventional regulation methods, and significantly improving the accuracy and efficiency of pH regulation. According to the same logical thinking as above, if sodium hydroxide, lime or sodium silicate and other reagents are used to regulate the pH value of the slurry, it is also possible to first establish a calibration fitting relationship curve and a fitting relationship curve formula between the mass volume percentage concentration of the reagent and the hydroxide ion concentration, and then accurately calculate the amount of the reagent and the amount of aqueous solution, which can also achieve efficient and precise regulation of the slurry pH value. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 When the concentration of tungsten tailings flotation pulp is 0%, 20%, and 30%, the mass volume percentage concentration of sodium carbonate and OH - Calibration fitting relationship curve of concentration and fitting relationship curve formula. DETAILED DESCRIPTION

[0026] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0027] Example 1

[0028] The method of the present invention was used to precisely control the pH value of the flotation slurry of tungsten tailings at a tungsten mine concentrator. The main chemical composition of the tungsten tailings, by mass percentage, is: WO3 0.350%, SiO2 64.840%, Al2O3 13.860%, CaO 2.620%, and MgO 2.260%. The particle size composition is: 72.080% is less than 0.038mm, and 91.500% is less than 0.074mm.

[0029] S1.1: Prepare 20% tungsten tailings flotation slurry and 5% sodium carbonate aqueous solution by volume;

[0030] S1.2: Add sodium carbonate aqueous solution to the tungsten tailings flotation pulp, adjust the pulp pH value, establish the relationship between the amount of sodium carbonate aqueous solution and the pulp pH value, convert and calculate, and obtain the mass volume percentage concentration of sodium carbonate and OH - Concentration relationship, establish relationship curve ( Figure 1 );

[0031] S1.3: Fit the relationship curve to obtain the mass volume percentage concentration of sodium carbonate and OH at 20% concentration - Calibration fitting relationship curve of concentration and fitting relationship curve formula.

[0032] The fitting relationship curve formula is: Y2=6.907×10 -2 X 6 -1.861×10 -1 X 5 +1.918×10 -1 X 4 -9.092×10 -2 X 3 +1.690×10 -2 X 2 +1.160×10 -3 X-7.964×10 −6 .

[0033] S2.1: In the laboratory test, 200g of tungsten tailings and 800mL of pure water were selected. Therefore, C S =200 / (200+800)=20.000%, the mass concentration of tungsten tailings flotation pulp is calculated to be 20.000%;

[0034] S2.2: Determine the target pH value to be 10.53 and convert the target OH - The concentration is Y2=3.388×10 -4 mol / L, call the calculate function in the Python 3.8 program to calculate the mass volume percentage concentration C of sodium carbonate T =0.157%, and the program code is as follows:

[0035] def calculate_Y(x):

[0036] return 6.907e-2*x**6-1.861e-1*x**5+1.918e-1*x**4-9.092e-2*x**3+1.690e-2*x**2+1.160e-3*x-7.964e-6

[0037] def find_root():

[0038] target=3.388e-4

[0039] left,right=0.0,0.8

[0040] epsilon=1e-6

[0041] while right-left>epsilon:

[0042] mid=(left+right) / 2

[0043] mid_value=calculate_Y(mid)

[0044] if mid_value <target:

[0045] left=mid

[0046] else:

[0047] right=mid

[0048] return(left+right) / 2

[0049] root=find_root()

[0050] print(f"The mass volume percentage concentration of sodium carbonate is {root:.3g}%")

[0051] S3.1: According to the formula , where: M T —Amount of sodium carbonate / g; C T —Sodium carbonate mass volume percentage concentration / %; M S —Mass of tungsten tailings / g; C S —Tungsten tailings slurry concentration / %, (Where: M L —Liquid mass of slurry / g). Calculate the amount of sodium carbonate used as the alkali adjustment agent M T =1.256g;

[0052] S3.2: According to the formula , where: V T —Amount of sodium carbonate aqueous solution / ml, c T - sodium carbonate aqueous solution mass volume percentage concentration / %, calculate the amount of aqueous solution of sodium carbonate as the alkali adjustment agent V T =25.120mL.

[0053] In practice, the target pH value is 10.53, the mass of sodium carbonate added is 1.250 g, and the amount of sodium carbonate solution used as the alkali adjustment agent is 25 mL. The errors compared with the calculated results in step S3.1 and step S3.2 are both 0.480%.

[0054] Example 2

[0055] The method of the present invention was used to precisely control the pH value of the flotation slurry of tungsten tailings at a tungsten mine. The main chemical composition and particle size composition of the tungsten tailings were consistent with those in Example 1.

[0056] S1.1: Prepare 30% tungsten tailings flotation slurry and 5% sodium carbonate aqueous solution by volume;

[0057] S1.2: Add sodium carbonate aqueous solution to the tungsten tailings flotation pulp, adjust the pulp pH value, establish the relationship between the amount of sodium carbonate aqueous solution and the pulp pH value, convert and calculate, and obtain the mass volume percentage concentration of sodium carbonate and OH - Concentration relationship, establish relationship curve ( Figure 1 );

[0058] S1.3: Fit the relationship curve to obtain the mass volume percentage concentration of sodium carbonate and OH at a concentration of 30%. - Calibration fitting relationship curve of concentration and fitting relationship curve formula.

[0059] The fitting relationship curve formula is: Y3=5.313×10 -2 X 6 -1.385×10 -1 X 5 +1.436×10 -1 X 4 -7.312×10 -2 X 3 +1.672×10 -2 X 2 +2.522×10 -4 X-4.394×10 −6 .

[0060] S2.1: In the laboratory test, 342.857 g of tungsten tailings and 800 mL of pure water were selected. Therefore, C S =342.857 / (342.857+800)=30.000%, the mass concentration of tungsten tailings flotation pulp is calculated to be 30.000%;

[0061] S2.2: Determine the target pH value to be 10.25 and convert the target OH - The concentration is Y3=1.778×10 -4mol / L, the same calculation method as in Example 1 was used to calculate the mass volume percentage concentration of sodium carbonate C by calling the calculate function in the Python 3.8 program. T =0.126%.

[0062] S3.1: According to the formula , where: M T —Amount of sodium carbonate / g; C T —Sodium carbonate mass volume percentage concentration / %; M S —Mass of tungsten tailings / g; C S —Tungsten tailings slurry concentration / %, (Where: M L —Liquid mass of slurry / g). Calculate the amount of sodium carbonate used as the alkali adjustment agent M T =1.008g.

[0063] S3.2: According to the formula , where: V T —Amount of sodium carbonate aqueous solution / ml, c T - sodium carbonate aqueous solution mass volume percentage concentration / %, calculate the amount of aqueous solution of sodium carbonate as the alkali adjustment agent V T =20.160mL.

[0064] In practice, the target pH value is 10.25, the mass of sodium carbonate added is 1.000 g, and the amount of sodium carbonate solution used as the alkali adjustment agent is 20 mL. The errors with the calculated results in step S3.1 and step S3.2 are both 0.800%.

[0065] The above two implementation cases show that the results obtained by the method of the present invention are compared with the actual situation, and the error is within the range of ±1%, indicating that the method is excellent.

[0066] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone skilled in the art may modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by one of ordinary skill in the art without departing from the spirit and technical principles disclosed herein are intended to be covered by the claims of the present invention.

Claims

1. A method for accurately controlling pH by adding sodium carbonate during the flotation process of tungsten tailings, characterized in that: The following steps are involved: S1: Through experiments, establish the relationship between the mass volume percentage concentration of sodium carbonate and OH after adding sodium carbonate aqueous solution as an alkali adjustment agent to tungsten tailings with different concentrations. - Calibration fitting relationship curve of concentration; S2: For the flotation pulp of a specific concentration, determine a target pH value to be achieved, select a calibration fitting relationship curve corresponding to the pulp concentration, and calculate the mass volume percentage concentration of sodium carbonate; S3: Convert the mass volume percentage concentration of sodium carbonate into the amount of sodium carbonate used as the alkali adjusting agent and the amount of aqueous solution used.

2. The method for accurately controlling pH by adding sodium carbonate during the flotation process of tungsten tailings according to claim 1, characterized in that: Step S1 specifically includes the following steps: S1.1: Prepare tungsten tailings flotation slurry and sodium carbonate aqueous solution as alkali adjustment agent; S1.2: In the flotation slurry of tungsten tailings, sodium carbonate aqueous solution is added to adjust the pH value of the slurry. The relationship between the amount of sodium carbonate aqueous solution used and the pH value of the slurry can be obtained; the amount of sodium carbonate aqueous solution is converted to the sodium carbonate concentration in the slurry, and the pH value is converted to the OH concentration of the slurry. - Concentration, that is, the relationship between the amount of sodium carbonate aqueous solution and the pH value of the pulp can be converted into the relationship between sodium carbonate concentration and OH - Concentration relationship, establish relationship curve; S1.3: Fitting the mass volume percentage concentration of sodium carbonate and OH - The concentration relationship curve is obtained, and the calibration fitting relationship curve and the fitting relationship curve formula are obtained. The horizontal axis X axis of the fitting curve is the mass volume percentage concentration of sodium carbonate, and the vertical axis Y axis is OH - concentration.

3. The method for accurately controlling pH by adding sodium carbonate during flotation of tungsten tailings according to claim 1, characterized in that: Step S2 specifically includes the following steps: S2.1: Determine and calculate the specific concentration of tungsten tailings flotation pulp; S2.2: Select the calibration fitting relationship curve corresponding to the slurry concentration, determine the target pH value that needs to be adjusted, and convert the target pH value into the target OH - concentration, OH - Substitute the concentration into the fitting curve formula and call the calculate function in the Python 3.8 program to calculate the mass volume percentage concentration of sodium carbonate.

4. The method for accurately controlling pH by adding sodium carbonate during the flotation process of tungsten tailings according to claim 1, characterized in that: Step S3 specifically includes the following steps: S3.1: The dosage of sodium carbonate as the alkali adjusting agent is based on formula 1: Calculated, where: M T —Amount of sodium carbonate / g; C T —Sodium carbonate mass volume percentage concentration / %; M S —Mass of tungsten tailings / g; C S —Tungsten tailings slurry concentration / %, (Where: M L —Liquid mass of slurry / g); S3.2: The amount of sodium carbonate aqueous solution is calculated according to formula 2: Calculated, where: V T —Amount of sodium carbonate aqueous solution / ml; c T —Mass volume percentage concentration of sodium carbonate aqueous solution / %.

5. The method for accurately controlling pH by adding sodium carbonate during flotation of tungsten tailings according to claim 2, characterized in that: The slurry concentration in step S1.1 is in the range of 20-30%, and the sodium carbonate aqueous solution concentration by mass volume is in the range of 1-6%.

6. The method for accurately controlling pH by adding sodium carbonate during flotation of tungsten tailings according to claim 3, characterized in that: The method for determining and calculating the concentration of tungsten tailings slurry in step S2.1 can be determined by the concentration pot method or other methods at industrial sites, while it can be directly calculated in laboratory tests.

Images