A method for preparing manganese tetroxide for drilling mud
By employing steps such as reduction leaching of pyrolusite powder, precipitation reaction of compound alkali-regulated solution, and hydrothermal treatment, combined with specific surfactants and complexing agents, the problems of high cost and poor performance in the preparation of manganese tetroxide for drilling mud have been solved. This has enabled the preparation of manganese tetroxide with high sphericity and uniform particle size, thereby improving the suspension stability and rheological properties of drilling fluid.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- GUIZHOU UNIV
- Filing Date
- 2026-05-18
- Publication Date
- 2026-06-30
Abstract
Description
Technical Field
[0001] This invention relates to the field of manganese tetroxide preparation technology, and more particularly to a method for preparing manganese tetroxide for drilling mud. Background Technology
[0002] Due to its high specific gravity and small particle size, manganese tetroxide has become the preferred material for high-performance weighting agents in drilling mud. Compared with traditional weighting agents such as barite and iron ore powder, it can effectively improve problems such as poor rheological properties, severe settling, and high friction of high-density drilling fluids. It is particularly suitable for drilling operations in high-temperature and high-pressure deep wells, ultra-deep wells, and wells with complex structures.
[0003] The performance requirements for manganese tetroxide (M3O4) used in drilling mud differ significantly from those for electronic grade and soft magnetic materials. Electronic grade and soft magnetic materials require high purity and low impurities, with morphology and particle size control being secondary requirements. However, drilling mud requires lower purity, and the types and contents of impurities are acceptable as long as they do not affect drilling performance. But there are strict requirements for sphericity and particle size. Low sphericity and wide particle size distribution can lead to poor suspension stability of the drilling fluid, causing erosion and wear on the drill string, and increasing the adhesion coefficient of the mud cake. At the same time, excessively large particle size can also affect the rheological properties of the drilling fluid.
[0004] Existing methods for preparing manganese tetroxide for drilling mud have many drawbacks: some methods use electrolytic manganese metal as raw material, which can produce qualified products, but the raw material cost is high and the wastewater treatment problem generated during the production of electronic-grade manganese tetroxide is not solved; some methods use pyrolusite as a low-cost raw material, but the special surfactants used in the preparation process are complex to synthesize and are not easy to obtain, which increases the production difficulty and cost; other methods treat the product by spray drying and ordinary air jet milling, resulting in high water content and rough surface of the product, which further affects the drilling performance.
[0005] Therefore, developing a simple, low-cost, and industrially suitable method for preparing manganese tetroxide for drilling mud is an urgent problem to be solved. Summary of the Invention
[0006] The purpose of this invention is to provide a method for preparing manganese tetroxide for drilling mud, thereby solving the above-mentioned problems existing in the prior art.
[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a method for preparing manganese tetroxide for drilling mud, comprising the following steps: S1. Disperse pyrolusite powder in water to form a suspension, and introduce SO2 gas to carry out a reduction leaching reaction to obtain manganese sulfate leachate; S2. Mix ammonia, anhydrous ethanol, and surfactant to obtain a composite alkali conditioning solution. Mix manganese sulfate leaching solution with the composite alkali conditioning solution to carry out a precipitation reaction. During the precipitation reaction, add ammonia to control the pH of the system to 10.0~10.5. After the precipitation reaction is completed, ripen to obtain a spherical precursor. S3. Disperse the spherical precursor in water to form a suspension, then add a catalyst and activator, and circulate air under stirring conditions to carry out an oxidation reaction to obtain a spherical crude manganese tetroxide. S4. Mix the near-spherical crude manganese tetroxide, manganese sulfate, ethanol solution, secondary surfactant, and complexing agent. Adjust the pH of the system to 8-8.5 and then carry out a hydrothermal reaction. After the hydrothermal reaction is completed, calcine to obtain manganese tetroxide for drilling mud.
[0008] Preferably, the flow rate of the SO2 gas is 50~100mL / min; the temperature of the reduction leaching reaction is 50~80℃; and the time of the reduction leaching reaction is 2~5h.
[0009] Preferably, the surfactant is one or more of hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, sodium dodecyl sulfate, and sodium dodecylbenzene sulfonate.
[0010] Preferably, the ratio of ammonia, anhydrous ethanol, and surfactant is 3-8 mL: 1-2 mL: 0.1-0.5 g; and the concentration of ammonia is 10-15%.
[0011] Preferably, the volume ratio of the manganese sulfate leaching solution to the composite alkali conditioning solution is 5~15:1~4.
[0012] Preferably, the precipitation reaction takes 2-6 hours, and the aging takes 1-4 hours.
[0013] Preferably, the mass ratio of the spherical precursor, catalyst, and activator is 1:0.001~0.01:0.001~0.005.
[0014] Preferably, the catalyst is ammonium chloride; the activator is ammonium hydroxide; the air flow rate is 0.1~1L / min; and the oxidation reaction time is 6~10h.
[0015] Preferably, the mass ratio of the near-spherical crude manganese tetroxide, manganese sulfate, secondary surfactant, and complexing agent is 100:20~40:1~5:1~10; the secondary surfactant is polyvinylpyrrolidone; and the complexing agent is triammonium citrate.
[0016] Preferably, the hydrothermal reaction temperature is 140~160℃; the hydrothermal reaction time is 2~5h; the calcination temperature is 300~350℃; and the calcination time is 1~3h.
[0017] As can be seen from the above technical solution, compared with the prior art, the present invention has the following beneficial effects: This invention utilizes commercially available surfactants and specific process conditions to effectively control the morphology of the precursor, achieving spherical growth and preliminary control of particle size. Furthermore, this invention performs in-situ shaping on the near-spherical crude manganese tetroxide obtained from oxidation, addressing issues such as surface depressions, sharp edges, and insufficient sphericity. By introducing an exogenous manganese source, combined with complexing agent complexation and secondary surfactant guidance, the manganese tetroxide is deposited and grown on the surface of the crude product, improving the sphericity and particle size uniformity of the near-spherical crude product. The finished manganese tetroxide product obtained by this invention has a sphericity >0.96 and D50 <1.2μm, with a smooth surface and uniform particle size distribution. When used as a drilling mud weighting agent, it exhibits good suspension stability, low drill string erosion rate, and low mud cake adhesion coefficient, meeting the drilling requirements of high-temperature, high-pressure deep and ultra-deep wells. Detailed Implementation
[0018] This invention provides a method for preparing manganese tetroxide for drilling mud, comprising the following steps: S1. Disperse pyrolusite powder in water to form a suspension, and introduce SO2 gas to carry out a reduction leaching reaction to obtain manganese sulfate leachate; S2. Mix ammonia, anhydrous ethanol, and surfactant to obtain a composite alkali conditioning solution. Mix manganese sulfate leaching solution with the composite alkali conditioning solution to carry out a precipitation reaction. During the precipitation reaction, add ammonia to control the pH of the system to 10.0~10.5. After the precipitation reaction is completed, ripen to obtain a spherical precursor. S3. Disperse the spherical precursor in water to form a suspension, then add a catalyst and activator, and circulate air under stirring conditions to carry out an oxidation reaction to obtain a spherical crude manganese tetroxide. S4. Mix the near-spherical crude manganese tetroxide, manganese sulfate, ethanol solution, secondary surfactant, and complexing agent. Adjust the pH of the system to 8-8.5 and then carry out a hydrothermal reaction. After the hydrothermal reaction is completed, calcine to obtain manganese tetroxide for drilling mud.
[0019] In this invention, the mass ratio of pyrolusite powder to water is preferably 1:5 to 10, more preferably 1:5 to 8, and even more preferably 1:6.
[0020] In this invention, the flow rate of the SO2 gas is preferably 50-100 mL / min, more preferably 60-100 mL / min, and even more preferably 100 mL / min.
[0021] In this invention, the temperature of the reduction leaching reaction is preferably 50~80℃, more preferably 55~70℃, and even more preferably 60℃; the time of the reduction leaching reaction is preferably 2~5h, more preferably 2~4h, and even more preferably 3h.
[0022] In this invention, the reduction leaching reaction process also includes stirring; the stirring speed is preferably 100~500 rpm, more preferably 150~400 rpm, and even more preferably 200 rpm.
[0023] In this invention, the surfactant is preferably one or more of hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, sodium dodecyl sulfate, and sodium dodecylbenzene sulfonate, more preferably hexadecyltrimethylammonium chloride or hexadecyltrimethylammonium bromide, and even more preferably hexadecyltrimethylammonium chloride.
[0024] In this invention, the preferred ratio of ammonia, anhydrous ethanol, and surfactant is 3-8 mL: 1-2 mL: 0.1-0.5 g, more preferably 4-6 mL: 1-1.5 mL: 0.2-0.4 g, and even more preferably 5 mL: 1 mL: 0.3 g; the preferred concentration of ammonia is 10-15%, more preferably 11-14%, and even more preferably 12%.
[0025] In this invention, the volume ratio of the manganese sulfate leaching solution to the composite alkali regulating solution is preferably 5~15:1~4, more preferably 7~12:2~4, and even more preferably 10:3.
[0026] In this invention, the precipitation reaction time is preferably 2-6 hours, more preferably 3-5 hours, and even more preferably 4 hours; the aging time is preferably 1-4 hours, more preferably 2-4 hours, and even more preferably 3 hours.
[0027] In this invention, the precipitation reaction process also includes stirring; the stirring speed is preferably 500~1000 rpm, more preferably 600~900 rpm, and even more preferably 800 rpm.
[0028] In this invention, the mass ratio of the spherical precursor to water is preferably 1:10 to 15, more preferably 1:11 to 14, and even more preferably 1:12.
[0029] In this invention, the mass ratio of the spherical precursor, catalyst, and activator is preferably 1:0.001~0.01:0.001~0.005, more preferably 1:0.003~0.008:0.002~0.004, and even more preferably 1:0.006:0.003.
[0030] In this invention, the catalyst is preferably ammonium chloride; the activator is preferably ammonium hydroxide.
[0031] In this invention, the flow rate of the introduced air is preferably 0.1~1L / min, more preferably 0.3~0.8L / min, and even more preferably 0.5L / min; the oxidation reaction time is preferably 6~10h, more preferably 7~9h, and even more preferably 8h.
[0032] In this invention, the stirring speed of the oxidation reaction is preferably 1000~2000 rpm, more preferably 1100~1600 rpm, and even more preferably 1200 rpm.
[0033] In this invention, the mass ratio of the spherical crude manganese tetroxide, manganese sulfate, secondary surfactant, and complexing agent is preferably 100:20~40:1~5:1~10, more preferably 100:25~35:1~4:2~8, and even more preferably 100:30:3:4.
[0034] In this invention, the secondary surfactant is preferably polyvinylpyrrolidone, and more preferably PVPK30.
[0035] In this invention, the complexing agent is preferably triammonium citrate.
[0036] In this invention, the temperature of the hydrothermal reaction is preferably 140~160℃, more preferably 145~155℃, and even more preferably 150℃; the time of the hydrothermal reaction is preferably 2~5h, more preferably 2~4h, and even more preferably 3h.
[0037] In this invention, the roasting temperature is preferably 300~350℃, more preferably 310~340℃, and even more preferably 320℃; the roasting time is preferably 1~3h, more preferably 2~3h, and even more preferably 2h.
[0038] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0039] Example 1
[0040] This embodiment provides a method for preparing manganese tetroxide for drilling mud, including the following steps: S1. Disperse pyrolusite powder in water at a mass ratio of 1:6 to form a suspension. Pass SO2 gas into the suspension at a flow rate of 100 mL / min and carry out a reduction leaching reaction at 200 rpm and 60℃ for 3 hours to obtain manganese sulfate leaching solution. S2. Mix 12% ammonia, anhydrous ethanol, and hexadecyltrimethylammonium chloride in a ratio of 5 mL: 1 mL: 0.3 g to obtain a composite alkali conditioning solution. Add manganese sulfate leaching solution dropwise to the composite alkali conditioning solution at a volume ratio of 10:3 over 3 hours. Then, carry out a precipitation reaction at 800 rpm for 4 hours. During the precipitation reaction, add 12% ammonia to control the pH of the system to 10.0. After the precipitation reaction is completed, allow it to mature for 3 hours to obtain a spherical precursor. S3. The spherical precursor was dispersed in water at a mass ratio of 1:12 to form a suspension. Then ammonium chloride and ammonium hydroxide were added (the mass ratio of spherical precursor, ammonium chloride and ammonium hydroxide was 1:0.006:0.003). The oxidation reaction was carried out by introducing air at a flow rate of 0.5 L / min under stirring at 1200 rpm for 8 hours to obtain crude spherical manganese tetroxide. S4. Mix the near-spherical crude manganese tetroxide, manganese sulfate, and ethanol solution (ethanol:water volume ratio 3:2) evenly. Then add PVP K30 and stir for 30 minutes. Next, add triammonium citrate, so that the ratio of near-spherical crude manganese tetroxide, manganese sulfate, PVP K30, triammonium citrate, and ethanol solution is 100mg:30mg:3mg:4mg:100mL. Adjust the pH of the system to 8.5 with ammonia water. Perform hydrothermal reaction at 150℃ for 3 hours. After the reaction is completed, wash the product with water 3 times, dry it, and calcine it at 320℃ for 2 hours to obtain manganese tetroxide for drilling mud.
[0041] The manganese tetroxide product obtained in this embodiment has a sphericity of 0.967, a D50 of 1.06 μm, and a density of 4.86 g / cm³. 3 .
[0042] Example 2
[0043] This embodiment provides a method for preparing manganese tetroxide for drilling mud, including the following steps: S1. Disperse pyrolusite powder in water at a mass ratio of 1:5 to form a suspension. Introduce SO2 gas at a flow rate of 80 mL / min and carry out a reduction leaching reaction at 500 rpm and 80℃ for 4 hours to obtain manganese sulfate leaching solution. S2. Mix 10% ammonia, anhydrous ethanol, and hexadecyltrimethylammonium bromide in a ratio of 4 mL: 2 mL: 0.1 g to obtain a composite alkali conditioning solution. Add manganese sulfate leaching solution dropwise to the composite alkali conditioning solution at a volume ratio of 8:3 over 3 hours. Then, carry out a precipitation reaction at 600 rpm for 5 hours. During the precipitation reaction, add 10% ammonia to control the pH of the system to 10.3. After the precipitation reaction is completed, allow it to mature for 2 hours to obtain a spherical precursor. S3. The spherical precursor was dispersed in water at a mass ratio of 1:10 to form a suspension. Then ammonium chloride and ammonium hydroxide were added (the mass ratio of spherical precursor, ammonium chloride and ammonium hydroxide was 1:0.005:0.005). The oxidation reaction was carried out under stirring at 1500 rpm and air was introduced at a flow rate of 0.3 L / min for 7 h to obtain spherical crude manganese tetroxide. S4. Mix the near-spherical crude manganese tetroxide, manganese sulfate, and ethanol solution (ethanol:water volume ratio 3:2) evenly. Then add PVP K30 and stir for 30 minutes. Next, add triammonium citrate, so that the ratio of near-spherical crude manganese tetroxide, manganese sulfate, PVP K30, triammonium citrate, and ethanol solution is 100mg:35mg:1mg:2mg:100mL. Adjust the pH of the system to 8.5 with ammonia water. Perform hydrothermal reaction at 140℃ for 2 hours. After the reaction is completed, wash the product with water 3 times, dry it, and calcine it at 300℃ for 3 hours to obtain manganese tetroxide for drilling mud.
[0044] The manganese tetroxide product obtained in this embodiment has a sphericity of 0.961, a D50 of 1.13 μm, and a density of 4.81 g / cm³. 3 .
[0045] Example 3
[0046] This embodiment provides a method for preparing manganese tetroxide for drilling mud, including the following steps: S1. Disperse pyrolusite powder in water at a mass ratio of 1:10 to form a suspension. Introduce SO2 gas at a flow rate of 90 mL / min and carry out a reduction leaching reaction at 500 rpm and 50℃ for 5 hours to obtain manganese sulfate leaching solution. S2. Mix 15% ammonia, anhydrous ethanol, and sodium dodecyl sulfate in a ratio of 8 mL: 1 mL: 0.5 g to obtain a composite alkali conditioning solution. Add manganese sulfate leaching solution dropwise to the composite alkali conditioning solution at a volume ratio of 5:4 over 3 hours. Then, carry out a precipitation reaction at 1000 rpm for 6 hours. During the precipitation reaction, add 15% ammonia to control the pH of the system to 10.2. After the precipitation reaction is completed, allow it to mature for 3 hours to obtain a spherical precursor. S3. Disperse the spherical precursor in water at a mass ratio of 1:15 to form a suspension, then add ammonium chloride and ammonium hydroxide (the mass ratio of spherical precursor, ammonium chloride, and ammonium hydroxide is 1:0.01:0.001). Under stirring at 2000 rpm, introduce air at a flow rate of 1 L / min to carry out the oxidation reaction. After reacting for 9 hours, obtain spherical crude manganese tetroxide. S4. Mix the near-spherical crude manganese tetroxide, manganese sulfate, and ethanol solution (ethanol:water volume ratio 3:2) evenly. Then add PVP K30 and stir for 30 minutes. Next, add triammonium citrate, so that the ratio of near-spherical crude manganese tetroxide, manganese sulfate, PVP K30, triammonium citrate, and ethanol solution is 100mg:30mg:4mg:2mg:100mL. Adjust the pH of the system to 8.5 using ammonia water. Perform hydrothermal reaction at 160℃ for 5 hours. After the reaction is complete, wash the product three times with water, dry it, and calcine it at 330℃ for 3 hours to obtain manganese tetroxide for drilling mud.
[0047] The manganese tetroxide product obtained in this embodiment has a sphericity of 0.962, a D50 of 1.17 μm, and a density of 4.74 g / cm³. 3 .
[0048] Comparative Example 1
[0049] This comparative example provides a method for preparing manganese tetroxide for drilling mud, as detailed in Example 1, except that cetyltrimethylammonium chloride is not added in step S2.
[0050] The manganese tetroxide product prepared in this comparative example has a sphericity of 0.568, a D50 of 15.43 μm, and a density of 4.15 g / cm³. 3 .
[0051] Comparative Example 2
[0052] This comparative example provides a method for preparing manganese tetroxide for drilling mud, as detailed in Example 1, except that step S4 is omitted.
[0053] The manganese tetroxide product prepared in this comparative example has a sphericity of 0.317, a D50 of 21.28 μm, and a density of 3.23 g / cm³. 3 .
[0054] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.
Claims
1. A method for preparing manganese tetroxide for drilling mud, characterized in that, Includes the following steps: S1. Disperse pyrolusite powder in water to form a suspension, and introduce SO2 gas to carry out a reduction leaching reaction to obtain manganese sulfate leachate; S2. Mix ammonia, anhydrous ethanol, and surfactant to obtain a composite alkali conditioning solution. Mix manganese sulfate leaching solution with the composite alkali conditioning solution to carry out a precipitation reaction. During the precipitation reaction, add ammonia to control the pH of the system to 10.0~10.
5. After the precipitation reaction is completed, ripen to obtain a spherical precursor. S3. Disperse the spherical precursor in water to form a suspension, then add a catalyst and activator, and circulate air under stirring conditions to carry out an oxidation reaction to obtain a spherical crude manganese tetroxide. S4. Mix the near-spherical crude manganese tetroxide, manganese sulfate, ethanol solution, secondary surfactant, and complexing agent. Adjust the pH of the system to 8-8.5 and then carry out a hydrothermal reaction. After the hydrothermal reaction is completed, calcine to obtain manganese tetroxide for drilling mud.
2. The method for preparing manganese tetroxide for drilling mud according to claim 1, characterized in that, The flow rate of the SO2 gas is 50~100mL / min; the temperature of the reduction leaching reaction is 50~80℃; and the time of the reduction leaching reaction is 2~5h.
3. The method for preparing manganese tetroxide for drilling mud according to claim 1, characterized in that, The surfactant is one or more of hexadecyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, sodium dodecyl sulfate, and sodium dodecylbenzene sulfonate.
4. The method for preparing manganese tetroxide for drilling mud according to claim 1, characterized in that, The ratio of ammonia, anhydrous ethanol, and surfactant used is 3-8 mL: 1-2 mL: 0.1-0.5 g; the concentration of ammonia is 10-15%.
5. The method for preparing manganese tetroxide for drilling mud according to claim 1, characterized in that, The volume ratio of the manganese sulfate leaching solution to the composite alkali conditioning solution is 5~15:1~4.
6. The method for preparing manganese tetroxide for drilling mud according to claim 1, characterized in that, The precipitation reaction takes 2-6 hours; the aging takes 1-4 hours.
7. The method for preparing manganese tetroxide for drilling mud according to claim 1, characterized in that, The mass ratio of the spherical precursor, catalyst, and activator is 1:0.001~0.01:0.001~0.
005.
8. The method for preparing manganese tetroxide for drilling mud according to claim 1, characterized in that, The catalyst is ammonium chloride; the activator is ammonium hydroxide; the air flow rate is 0.1~1L / min; and the oxidation reaction time is 6~10h.
9. The method for preparing manganese tetroxide for drilling mud according to claim 1, characterized in that, The mass ratio of the spherical crude manganese tetroxide, manganese sulfate, secondary surfactant, and complexing agent is 100:20~40:1~5:1~10; the secondary surfactant is polyvinylpyrrolidone; and the complexing agent is triammonium citrate.
10. A method for preparing manganese tetroxide for drilling mud according to claim 1, characterized in that, The hydrothermal reaction temperature is 140~160℃; the hydrothermal reaction time is 2~5h; the calcination temperature is 300~350℃; the calcination time is 1~3h.