Method for preparing potassium magnesium alum by using underground native sulfur-rich potassium-containing minerals in high-temperature state

Abstract

A method for preparing potassium magnesium alum by using underground primary sulfur-rich potassium-containing minerals in a high-temperature state comprises the following steps: S1, performing multi-stage crushing on raw ores to obtain the sulfur-rich potassium-containing minerals; s2, sulfur-rich potassium-containing minerals and seawater are mixed and then stirred, the stirring time is 40-150 min, the conversion temperature is controlled to be 35-50 DEG C, and solid-liquid mixed ore pulp is obtained; s3, the solid-liquid mixed ore pulp is subjected to pulp mixing with a potassium magnesium alum flotation mother solution to control the flotation concentration, flotation is conducted after a flotation reagent is added and mixed to be uniform, the dosage of the flotation reagent is 250-500 g / ton raw ore, and the flotation reagent is an organic sodium salt aqueous solution generated after heavy oil is subjected to chlorination, sulfonation and saponification; and S4, flotation froth obtained in flotation is filtered and separated, solids are potassium magnesium alum concentrates, after tailings are concentrated, obtained high-concentration tailings are discharged, and flotation mother liquor generated through flotation filtration or concentration is partially returned to the step S3 to be used for size mixing. The method is simple in process and good in product quality.

Description

Technical Field

[0001] The present invention relates to the field of a preparation method of langbeinite, and particularly relates to a method for preparing langbeinite by using underground primary sulfur-rich potassium-containing minerals at high temperature. Background Art

[0002] At present, the processing technology for producing potassium sulfate from magnesium sulfate subtype brine is to first flotate (or flotate after conversion) part of the potassium mixed salt to obtain langbeinite concentrate, and convert and flotate the other part of the potassium mixed salt (such as carnallite and potassium salt) to obtain KCl. Langbeinite and KCl are converted under certain conditions to produce potassium sulfate.

[0003] However, there are few methods for preparing langbeinite by using sulfur-rich potassium-containing minerals. CN108349743A discloses a method for producing potassium sulfate from potassium-containing ore at high ambient temperature. This method can operate at a relatively high temperature, especially at a temperature higher than 35°C, and does not require a process step of operating at a temperature lower than 35°C, especially a cooling step at 20 to 25°C. The process can operate economically in hot and dry regions with limited available resources. However, the raw material of this method is an aqueous composition containing potassium and sulfate radicals, that is, the principle of this process treatment is for aqueous substances, and a large amount of fresh water is used in the process. For the preparation of langbeinite using underground primary minerals in a high-temperature environment lacking fresh water, there are few literature reports.

[0004] In order to improve the product purity and conversion rate, those skilled in the art are committed to finding suitable flotation reagents. CN102476075B discloses a combined organic sodium sulfonate flotation agent, which is composed of sodium alkyl sulfonate, sodium dodecyl benzene sulfonate and sodium butyl naphthalene sulfonate. Among them, the mass percentage content of sodium alkyl sulfonate is 50-90%, the mass percentage content of sodium dodecyl benzene sulfonate is 7-30%, and the mass percentage content of sodium butyl naphthalene sulfonate is 3-20%. It can significantly improve the quality of low-grade mixed salts, with a short flotation time and high flotation efficiency. Although the flotation agent developed in this patent has high efficiency, its actual yield is not significantly improved compared with sodium dodecyl sulfonate, and the yield of the concentrate is not high. Summary of the Invention

[0005] (1) Technical Problems to be Solved

[0006] In view of the above-mentioned disadvantages and deficiencies of the prior art, the present invention provides a method for preparing langbeinite by using underground primary sulfur-rich potassium-containing minerals in a high-temperature state and an environment lacking fresh water.

[0007] (2) Technical Solutions

[0008] To achieve the above object, an embodiment of the present invention provides a method for preparing langbeinite by using underground native sulfur-rich potassium minerals at high temperature, comprising the steps:

[0009] S1, Crushing: The mined underground native sulfur-rich potassium ore is subjected to multi-stage crushing to obtain sulfur-rich potassium minerals with the required particle size.

[0010] S2, Conversion: The sulfur-rich potassium minerals and seawater are mixed and stirred for 40 min to 150 min, and the conversion temperature is controlled at 35°C to 50°C to obtain a solid-liquid mixed slurry.

[0011] S3, Flotation: The solid-liquid mixed slurry is adjusted with the langbeinite flotation mother liquor to control the flotation concentration, and after adding flotation reagents and mixing evenly, flotation is carried out. The dosage of the flotation reagent is 250 g / ton of raw ore to 500 g / ton of raw ore. The flotation reagent is an aqueous solution of organic sodium salt produced by chlorination, sulfonation, and saponification of heavy oil.

[0012] S4, Concentration and filtration: The flotation foam obtained in the flotation is filtered and separated. The obtained solid is the langbeinite concentrate. The obtained tailings are concentrated, and the high-concentration tailings are discharged. The flotation mother liquor generated by flotation filtration or concentration is returned to step S3 for pulp adjustment.

[0013] In one embodiment, the final particle size of the multi-stage crushing is -1 mm to -2 mm.

[0014] In one embodiment, the main components of the underground native sulfur-rich potassium ore are K + 8.0% to 13.0%, Na + 8.0% to 21.0%, Mg 2+ 5.0% to 8.0%, Cl- 23.0% to 35.0%, SO 4 2- 25.0% to 31.0%.

[0015] In one embodiment, the mass ratio of the native sulfur-rich potassium ore to seawater is 1:0.45 to 0.75.

[0016] In one embodiment, the effective components of the aqueous solution of organic sodium salt are sodium petroleum sulfonate with a carbon chain length of 12 to 16 and sodium chloride.

[0017] In one embodiment, the mass percentage content of sodium petroleum sulfonate in the flotation reagent is 24% - 25%, and the mass percentage content of sodium chloride is ≤8%.

[0018] In one embodiment, the flotation is a closed-circuit process of one rough selection and one fine selection, and the middlings in the fine selection are returned to the rough selection.

[0019] In one embodiment, the solid phase mass content in rough selection is 25% - 35%, and the solid phase mass content in fine selection is 10% - 15%.

[0020] (III) Beneficial effects

[0021] The beneficial effects of the present invention are as follows: In the present invention, a method for preparing langbeinite from underground primary sulfur-rich potassium-containing minerals is proposed specifically for the environment of underground primary sulfur-rich potassium-containing minerals being a high-temperature environment (room temperature is 25°C, and the high temperature in this application refers to higher than 35°C), and the lack of fresh water conditions in the mining area. First, since the original ore to be processed is underground primary sulfur-rich potassium-containing minerals, in order to save costs and improve efficiency, this application first uses multi-stage crushing to crush the original ore to the required particle size, which greatly saves equipment energy consumption and time compared with single-stage crushing. Compared with the prior art that mostly uses fresh water for conversion, due to the lack of fresh water in the ore source area, seawater can only be used. However, in general methods, since the content of sodium chloride in seawater is much higher than that in fresh water, and in the general process of preparing langbeinite, sodium chloride has an adverse effect on the reaction product. Therefore, even if there is a lack of fresh water, seawater will be first treated to fresh water, which greatly increases the process cost. In this application, seawater is directly used for conversion at a temperature of 35°C - 50°C, and then the sodium salts precipitated from the original ore and the high-sodium medium seawater added in the conversion process are removed through a flotation process, thereby increasing the content of langbeinite, greatly saving the cost of preparing fresh water. At the same time, in this application, an organic sodium salt solution produced by chlorination, sulfonation, and saponification of heavy oil is selected as the flotation reagent to efficiently capture langbeinite. The removal rates of Na + and Cl - in the obtained rough langbeinite concentrate reach over 88%, while the conversion rates of K + , Mg 2+ and SO 4 2- reach 90%. The method for preparing langbeinite from underground primary sulfur-rich potassium-containing minerals at high temperature in this application has a simple process. The langbeinite product can be obtained only through crushing - conversion - flotation and concentration filtration. Moreover, the energy consumption and cost of the process are relatively low, while the product yield and quality obtained are very good, and it is applicable to industrial production. Specific embodiments

[0022] In order to better explain the present invention for easy understanding, the present invention will be described in detail below through specific embodiments.

[0023] An embodiment of the present invention provides a method for preparing langbeinite from underground primary sulfur-rich potassium-containing minerals at high temperature, including the steps:

[0024] S1, Crushing, performing multi-stage crushing on the mined underground primary sulfur-rich potassium-containing original ore to obtain sulfur-rich potassium-containing minerals with the required particle size;

[0025] Specifically, in one embodiment, two-stage crushing or more than two-stage crushing can be adopted. The particle size of the previous crushing is smaller than that of the subsequent crushing, and the final particle size of the last-stage crushing is -1 mm to -2 mm. Adopting multiple crushing can effectively save energy consumption and crushing time compared with single crushing. In addition, controlling the particle size within -1 mm to -2 mm can achieve better subsequent conversion while controlling the cost within a reasonable range.

[0026] Specifically, the main components of the underground primary sulfur-rich potassium-containing raw ore are K + 8.0% to 13.0%, Na + 8.0% to 21.0%, Mg 2+ 5.0% to 8.0%, Cl - 23.0% to 35.0%, SO 4 2- 25.0% to 31.0%.

[0027] S2, conversion: Mix the sulfur-rich potassium-containing mineral and seawater and stir. The stirring time is 40 min to 150 min, and the conversion temperature is controlled at 35°C to 50°C to obtain a solid-liquid mixed pulp.

[0028] Specifically, in one embodiment, the mass ratio of the primary sulfur-rich potassium-containing raw ore to seawater is 1:0.45 to 0.75 K + When the concentration is relatively high, a higher amount of seawater is required. When K + When the concentration is relatively low, the required amount of seawater can be appropriately reduced. In short, the mass ratio is controlled within the range of 1:0.45 to 0.75.

[0029] S3, flotation: Adjust the pulp of the solid-liquid mixed pulp with the carnallite flotation mother liquor to control the flotation concentration. After adding the flotation reagent and mixing evenly, carry out flotation. The dosage of the flotation reagent is 250 g / ton of raw ore to 500 g / ton of raw ore. The flotation reagent is an aqueous solution of organic sodium salt produced by chlorination, sulfonation, and saponification of heavy oil.

[0030] Specifically, the flotation is a closed-circuit process of one rough selection and one fine selection, and the middlings in the fine selection are returned to the rough selection. Among them, the solid-phase mass content in the rough selection is 25% to 35%, and the solid-phase mass content in the fine selection is 10% to 15%.

[0031] Specifically, the effective components of the aqueous solution of organic sodium salt are sodium petroleum sulfonate with a carbon chain length of 12 to 16 and sodium chloride. The mass percentage content of sodium petroleum sulfonate in the flotation reagent is 24% - 25%, and the mass percentage content of sodium chloride ≤ 8%.

[0032] In this application, the flotation reagent is an aqueous solution of organic sodium salt produced by chlorination, sulfonation, and saponification of heavy oil. The effective components of the aqueous solution of organic sodium salt are sodium petroleum sulfonate with a carbon chain length of 12 - 16 and sodium chloride. The mass percentage content of sodium petroleum sulfonate in the flotation reagent is 24% - 25%, and the mass percentage content of sodium chloride ≤ 8%. Compared with directly using pure substances of sodium petroleum sulfonate with a carbon chain length of 12 - 16 and sodium chloride to prepare the flotation reagent or other flotation reagents, the effect cannot reach the flotation effect of this application.

[0033] S4, concentration and filtration: Filter and separate the flotation foam obtained in flotation. The obtained solid is the langbeinite concentrate. After the obtained tailings are concentrated, the high-concentration tailings are discharged. Part of the flotation mother liquor generated by flotation filtration or concentration is returned to step S3 for pulp adjustment, and the excess part enters the salt field for evaporation, concentration, and stepwise sun drying of potassium-containing minerals and then returns to the processing system.

[0034] Specifically, through the above process and the selected reagents, the langbeinite flotation concentrate K + recovery rate is about 70%, and the yield of flotation concentrate is between 42% - 51%.

[0035] The present invention will be further described below in conjunction with embodiments. The raw materials used in the embodiments of the present invention are underground primary sulfur-rich potassium-containing minerals. The elemental compositions of the underground primary sulfur-rich potassium-containing minerals in Embodiments 1 - 3 are shown in Table 1:

[0036] Table 1 Composition of underground primary sulfur-rich potassium-containing minerals in Embodiments 1 - 3

[0037]

[0038] The flotation reagent used in the embodiments of the present invention is an aqueous solution of organic sodium salt produced by chlorination, sulfonation, and saponification of heavy oil, and is prepared to a mass concentration of 2% with fresh water before use; other chemical reagents used, unless otherwise specified, are obtained through conventional commercial channels.

[0039] Embodiment 1 (Kururi Potash Mine)

[0040] (1) Crushing: Crush the underground primary sulfur-rich potassium-containing minerals to -2 mm.

[0041] (2) Conversion: Mix the crushed raw ore and seawater in a mass ratio of 1:0.55 and stir. The stirring time is 150 min, and the conversion temperature is controlled at 35 °C to obtain a decomposed solid-liquid mixed pulp;

[0042] (3) Flotation: The solid-liquid mixed pulp is adjusted to a controlled concentration with the mother liquor of langbeinite flotation, and after adding flotation reagents and mixing evenly, it enters the flotation machine for flotation. The flotation process is a closed-circuit process with one rough selection and one fine selection, and the middlings from the fine selection are returned to the rough selection. Among them, the mass concentration of the rough selection is 35%, and the concentration of the fine selection is 15%. The flotation reagent is an aqueous solution of organic sodium salt produced by chlorination, sulfonation, and saponification of heavy oil, which is added only in the rough selection, and the dosage of the reagent is 375 g / ton of raw ore.

[0043] (4) Concentration and filtration: The flotation foam obtained in the flotation is filtered and separated, and the obtained solid is the langbeinite concentrate, and its chemical composition is K + 17.13%, Na + 1.320%, Mg 2+ 5.629%, Cl - 3.920%, SO 4 2- 40.74%, and it is retained for use; after the tailings are concentrated, the high-concentration tailings obtained are discharged. Part of the mother liquor of langbeinite flotation generated by the filtration of the concentrate and the concentration of the tailings in the flotation is returned to step (3) for recycling; the excess part enters the salt pan for evaporation, concentration, and grading to sun-dry potassium-containing minerals and then returns to the processing system.

[0044] Through the above process, the yield of the flotation concentrate is 47.29%, and the recovery rate of K + is 70.25%. (The yield and recovery rate are determined according to the K + content in the raw ore).

[0045] Example 2 (Kuruli potassium salt mine)

[0046] (1) Crushing: The underground primary sulfur-rich potassium-containing minerals are crushed to -1.45 mm.

[0047] (2) Conversion: The crushed raw ore and seawater are mixed at a mass ratio of 1:0.75 and then stirred. The stirring time is 120 min, and the conversion temperature is controlled at 40 °C to obtain the decomposed solid-liquid mixed pulp;

[0048] (3) Flotation: The solid-liquid mixed pulp is adjusted to a controlled concentration with the mother liquor of langbeinite flotation, and after adding flotation reagents and mixing evenly, it enters the flotation machine for flotation. The flotation process is a closed-circuit process with one rough selection and one fine selection, and the middlings from the fine selection are returned to the rough selection. Among them, the mass concentration of the rough selection is 30%, and the concentration of the fine selection is 12%. The flotation reagent is an aqueous solution of organic sodium salt produced by chlorination, sulfonation, and saponification of heavy oil, which is added only in the rough selection, and the dosage of the reagent is 500 g / ton of raw ore.

[0049] (4) Concentration and filtration: The flotation foam obtained in the flotation is filtered and separated, and the obtained solid is the langbeinite concentrate, and its chemical composition is K + 16.65%, Na + 2.01%, Mg 2+5.240%, Cl - 2.555%, SO 4 2- 41.90%, for retention; after the tailings are concentrated, the high-concentration tailings are discharged. Part of the flotation mother liquor generated from the filtration of the concentrate and the concentration of the tailings in flotation is recycled to step (3), and the excess part enters the salt field for evaporation concentration, graded sun drying of potassium-containing minerals, and then returns to the processing system.

[0050] Through the above process, the yield of the flotation concentrate is 51.06%, K + recovery rate is 69.46%. (The yield and recovery rate are determined based on the K + content in the original ore).

[0051] Example 3 (Kuruli Potassium Salt Mine)

[0052] (1) Crushing: Crush the underground primary sulfur-rich potassium-containing minerals to -1 mm.

[0053] (2) Conversion: Mix the crushed original ore and seawater in a mass ratio of 1:0.45, stir for 60 min, and control the conversion temperature at 45 °C to obtain a decomposed solid-liquid mixed pulp;

[0054] (3) Flotation: Adjust the concentration of the solid-liquid mixed pulp with the carnallite flotation mother liquor, add flotation reagents and mix well, then enter the flotation machine for flotation. The flotation process is a closed-circuit process of one rough selection and one fine selection, and the middlings from the fine selection are returned to the rough selection. Among them, the mass concentration of the rough selection is 25%, and the concentration of the fine selection is 10%. The flotation reagent is an aqueous solution of organic sodium salt produced by chlorination, sulfonation, and saponification of heavy oil, which is only added in the rough selection, and the dosage is 250 g / t of the original ore.

[0055] (4) Concentration and filtration: Filter and separate the flotation foam obtained in flotation. The resulting solid is the carnallite concentrate, and its chemical composition is K + 16.74%, Na + 1.965%, Mg 2+ 5.247%, Cl - 2.139%, SO 4 2- 42.51%, for retention; after the tailings are concentrated, the high-concentration tailings are discharged. Part of the flotation mother liquor generated from the filtration of the concentrate and the concentration of the tailings in flotation is recycled to step (3), and the excess part enters the salt field for evaporation concentration, graded sun drying of potassium-containing minerals, and then returns to the processing system.

[0056] Through the above process, the yield of the flotation concentrate is 42.21%, K + recovery rate is 67.52%. (The yield and recovery rate are determined based on the K + content in the original ore).

[0057] According to the above embodiments, in the present invention, first, the present application first uses multi-stage crushing to crush the raw ore to the required particle size. Compared with single-stage crushing, it greatly saves equipment energy consumption and time. Then, compared with the prior art which mostly uses fresh water for conversion, due to the lack of fresh water in the ore source area, seawater has to be used. However, in general methods, since the content of sodium chloride in seawater is much higher than that in fresh water, and in the general process of producing langbeinite, sodium chloride has an adverse effect on the reaction product. Therefore, even if fresh water is lacking, seawater will be first treated and desalinated into fresh water, which greatly increases the process cost. In the present application, seawater is directly used for conversion at a temperature of 35°C to 50°C, and then the sodium salts precipitated from the raw ore and the seawater with high-sodium medium added in the conversion process are removed through the flotation process, thereby increasing the content of langbeinite, greatly saving the cost of preparing fresh water. At the same time, in the present application, an organic sodium salt solution produced by chlorination, sulfonation, and saponification of heavy oil is selected as the flotation reagent to efficiently capture langbeinite, and the removal rates of Na + and Cl - in the obtained langbeinite rough concentrate reach over 88%, while the conversion rates of K + , Mg 2+ and SO 4 2- reach 90%. The method for producing langbeinite by using underground primary sulfur-rich potassium minerals at high temperature in the present application has a simple process. The langbeinite product can be obtained only through crushing - conversion - flotation and concentration filtration. Moreover, the energy consumption and cost of the process are relatively low, while the product yield and quality obtained are very good, and it is applicable to industrial production.

[0058] In the description of this specification, the descriptions of terms such as "one embodiment", "some embodiments", "embodiment", "example", "specific example", or "some examples" mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in a suitable manner in any one or more embodiments or examples. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0059] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for preparing kainite by using underground primary sulfur-rich potassium-containing minerals under high temperature conditions, It is characterized in that include: S1, crushing, the mined underground original sulfur-rich potassium ore is crushed in multiple stages to obtain sulfur-rich potassium ore with the required particle size; S2, conversion, mixing the sulfur-rich potassium-containing mineral and seawater and stirring and converting them to obtain a solid-liquid mixed slurry; S3, flotation: solid-liquid mixed slurry is slurried with potassium magnesium sulfate flotation mother liquor to control the flotation concentration, and flotation is performed after adding flotation reagent and mixing. The flotation reagent is an organic sodium salt aqueous solution produced by chlorination, sulfonation and saponification of heavy oil; S4, concentration and filtration: the flotation foam obtained in the flotation is filtered and separated, and the obtained solid is the potassium magnesium sulfate concentrate. After the obtained tailings are concentrated, the high-concentration tailings are discharged, and the flotation mother liquor produced by flotation filtration or concentration is returned to step S3 for slurry preparation.

2. The method for preparing kainite by using underground primary sulfur-rich potassium-containing minerals under high temperature conditions according to claim 1, characterized in that: The final particle size of the multi-stage crushing is -1mm to -2mm.

3. The method for preparing kainite by using underground primary sulfur-rich potassium-containing minerals under high temperature conditions according to claim 1, characterized in that: The main components of the underground primary sulfur-rich potassium ore are K + 8.0%~13.0%, Na + 8.0%~21.0%, Mg 2+ 5.0%~8.0%, Cl - 23.0%~35.0%, SO4 2- 25.0%~31.0%.

4. The method for preparing kainite by using underground primary sulfur-rich potassium-containing minerals under high temperature conditions according to claim 1, characterized in that: The mass ratio of the original sulfur-rich potassium-containing ore to seawater is 1:0.45-0.75, the stirring time is 40min-150min, and the conversion temperature is controlled at 35°C-50°C.

5. The method for preparing kainite by using underground primary sulfur-rich potassium-containing minerals under high temperature conditions according to claim 1, characterized in that: The effective components of the organic sodium salt aqueous solution are petroleum sulfonic acid sodium salt with a carbon chain length of 12 to 16 and sodium chloride, and the dosage is 250 g to 500 g per ton of raw ore.

6. The method for preparing kainite by using underground primary sulfur-rich potassium-containing minerals under high temperature conditions according to claim 5, characterized in that: The mass percentage of petroleum sulfonic acid sodium salt in the flotation reagent is 24%-25%, and the mass percentage of sodium chloride is ≤8%.

7. The method for preparing kainite by using underground primary sulfur-rich potassium-containing minerals under high temperature conditions according to claim 1, characterized in that: The flotation is a closed-circuit process in which roughing is performed once and concentrating is performed once, and the concentrating middlings are returned to the roughing.

8. The method for preparing kainite by using underground primary sulfur-rich potassium-containing minerals under high temperature conditions according to claim 7, characterized in that: The solid content in the rough selection is 25% to 35%, and the solid content in the fine selection is 10% to 15%.

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