Method for extracting and recovering sec-octanol from tantalum-niobium acid wastewater

Abstract

The invention discloses a method for extracting and recovering sec-octanol from tantalum-niobium acid wastewater, the tantalum-niobium acid wastewater is acid wastewater generated in the process of extracting tantalum and niobium by using sec-octanol, and the method comprises the following steps: S1, dilution: uniformly mixing odorless kerosene and n-dodecane according to a certain proportion to obtain diluted n-dodecane; s2, extraction: adding the diluted n-dodecane obtained in S1 into the tantalum-niobium acid wastewater to extract the sec-octanol to obtain raffinate and an organic phase containing the sec-octanol, and performing centralized treatment on the raffinate; s3, distillation: distilling the organic phase containing the sec-octanol obtained in the S2 to obtain a sec-octanol product and diluted n-dodecane, and recycling the diluted n-dodecane in the S2. According to the method disclosed by the invention, short-range purification of the sec-octyl alcohol in the acid wastewater and cyclic utilization of n-dodecane are realized, meanwhile, the problem that the taste of the acid wastewater is strong is solved, and resource circulation and high-value utilization of the sec-octyl alcohol are realized. The method has the characteristics of environmental friendliness, high resource utilization rate and simple and feasible process.

Description

Technical Field

[0001] The invention belongs to the technical field of wastewater treatment and relates to a method for extracting and recovering secondary octanol from tantalum-niobium acid wastewater. Background Art

[0002] In recent years, with the rapid development of electronics, aviation, chemical industry and other fields, tantalum has excellent electrical conductivity and corrosion resistance, and niobium has the characteristics of enhancing the strength and toughness of steel, making these two rare metals play an irreplaceable role in the development of modern industry and science and technology. The production processes of tantalum and niobium mainly include acid leaching, solvent extraction and electrolysis, etc., and acid leaching recovery is currently the main method. CN201410660973 discloses a method for preparing ultra-high purity tantalum oxide, and proposes to use 2-octanol to extract tantalum and prepare ultra-high purity tantalum oxide. Therefore, the method of extracting tantalum and niobium with 2-octanol to prepare high-purity products is widely used, but a large amount of acidic wastewater will be generated in the process.

[0003] These acidic wastewaters have the characteristics of complex composition and high content of sec-octanol. The treatment of sec-octanol is the core of high-value utilization of acidic wastewater. The main reason is that some sec-octanol dissolves in acidic wastewater, resulting in a strong smell of wastewater; at the same time, sec-octanol as an organic solvent has significant economic value, and its versatility and wide range of applications make it an important chemical raw material. In recent years, with the rapid development of electronic information technology, the demand for tantalum and niobium has increased year by year. While wet processing of ores to recover valuable metal elements, the discharge of acidic wastewater has shown a rapid growth trend. Among them, the high economic value of sec-octanol and the strong smell of acidic wastewater have attracted much attention. Traditional sec-octanol recovery technology faces many challenges, such as complex operation, high cost, low processing efficiency and other problems. CN201910191881 discloses a method for recovering sec-octanol from lincomycin extraction waste liquid, and proposes to use an adsorption medium as an adsorbent to recover sec-octanol from wastewater with a recovery rate of 78%. This method requires multiple mixing of liquids, which results in tedious operations; requires the addition of acid with a concentration of 20 to 60% for acidification, and requires a large amount of acid to be added; and has a recovery efficiency of 78%, which is a low recovery rate.

[0004] Therefore, an efficient, economical and environmentally friendly treatment method is urgently needed to meet this challenge. Summary of the invention

[0005] In order to solve the problems of long process and low recovery rate, the present invention proposes a method for extracting and recovering sec-octanol from tantalum-niobium acidic wastewater, using n-dodecane as an extractant to extract sec-octanol in the acidic wastewater, and obtaining high-purity sec-octanol by distillation. The method realizes the short-range purification of sec-octanol in acidic wastewater and the recycling of n-dodecane, while solving the problem of strong smell of acidic wastewater, and realizing the resource recycling and high-value utilization of sec-octanol. In addition, the method is environmentally friendly, has high resource utilization rate and is simple and easy to operate.

[0006] In order to achieve the above purpose, this application adopts the following technical solutions:

[0007] A method for extracting and recovering 2-octanol from tantalum-niobium acidic wastewater, wherein the tantalum-niobium acidic wastewater refers to acidic wastewater generated during the extraction of tantalum-niobium using 2-octanol, comprising the following steps:

[0008] S1, dilution: mixing odorless kerosene and n-dodecane in a certain proportion to obtain diluted n-dodecane;

[0009] S2, extraction: adding the diluted n-dodecane obtained in S1 to the tantalum-niobium acid wastewater to extract the secondary octanol, obtaining a raffinate and an organic phase containing the secondary octanol, and centrally treating the raffinate;

[0010] S3, distillation: distilling the organic phase containing sec-octanol obtained in S2 to obtain sec-octanol product and diluted n-dodecane, and the diluted n-dodecane is recycled to S2.

[0011] In the above technical solution, during the dilution process, n-dodecane accounts for 20-60% of the odorless kerosene, wherein the boiling point of the odorless kerosene is 195-300° C., and the homogenization time is 5-15 minutes.

[0012] In the above technical scheme, during the extraction process, the ratio of diluted n-dodecane to tantalum-niobium acid wastewater is 2-0.5, the extraction time is 3-10 minutes, and the phase separation time is 4-10 minutes.

[0013] In the above technical solution, during the distillation process, the distillation temperature is 180-210° C. and the distillation time is 30-100 min.

[0014] The beneficial effects of the present invention are as follows: compared with the prior art, the present invention uses n-dodecane to recover sec-octanol in acidic wastewater, and uses n-dodecane as an extractant to extract sec-octanol in one step. A high-purity sec-octanol product is obtained by distillation, and the diluted n-dodecane obtained is recycled. This method does not require the addition of other reagents during implementation, realizes short-range purification of sec-octanol, and solves the problem of strong taste in acidic wastewater, and has the characteristics of simple and easy process, high resource utilization rate, and environmental friendliness. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 The present invention is a flow chart of a method for extracting and recovering sec-octanol from tantalum-niobium acid waste water. DETAILED DESCRIPTION

[0016] In order to better illustrate the purpose, technical solutions and advantages of the present invention, the present invention will be further described below in conjunction with specific embodiments. The present invention can be implemented in many different forms and should not be construed as being limited to the embodiments set forth herein. On the contrary, these embodiments are provided so that this disclosure will be thorough and complete, and the concept of the present invention will be fully conveyed to those skilled in the art, and the present invention will only be limited by the claims.

[0017] The present invention relates to the treatment of acidic wastewater generated in the production process of tantalum and niobium and the purification and recovery technology of octanol, in particular to a new method of extracting octanol in acidic wastewater using n-dodecane organic phase, thereby providing a method for extracting and recovering octanol from tantalum and niobium acidic wastewater.

[0018] Example 1

[0019] A method for extracting and recovering sec-octanol from tantalum-niobium acid wastewater comprises the following steps:

[0020] (1) Dilution: Mix odorless kerosene and n-dodecane evenly to obtain diluted n-dodecane, wherein n-dodecane accounts for 40% of the odorless kerosene, the boiling point of the odorless kerosene is 220° C., and the homogenization time is 7 min;

[0021] (2) Extraction: adding the diluted n-dodecane obtained in step (1) to the tantalum-niobium acidic wastewater to extract the octanol, obtaining a raffinate and an organic phase containing the octanol, and centrally treating the raffinate, wherein the ratio of the diluted n-dodecane to the tantalum-niobium acidic wastewater is 2, the extraction time is 7 min, and the phase separation time is 8 min;

[0022] (3) Distillation: distilling the organic phase containing octanol obtained in step (2) to obtain octanol product and diluted n-dodecane, and recycling the diluted n-dodecane to step (2), wherein the distillation temperature is 200° C. and the distillation time is 80 min.

[0023] The extraction rate of 2-octanol is 99.56%, and the purity of the obtained 2-octanol is 99.12%, which meets the testing requirements of the national standard GB / T9722-2023 general rules for gas chromatography.

[0024] Example 2

[0025] A method for extracting and recovering sec-octanol from tantalum-niobium acid wastewater comprises the following steps:

[0026] (1) Dilution: Mix odorless kerosene and n-dodecane evenly to obtain diluted n-dodecane, wherein n-dodecane accounts for 30% of the odorless kerosene, the boiling point of the odorless kerosene is 250° C., and the homogenization time is 10 min;

[0027] (2) Extraction: adding the diluted n-dodecane obtained in step (1) to the tantalum-niobium acidic wastewater to extract the octanol, obtaining a raffinate and an organic phase containing the octanol, and centrally treating the raffinate, wherein the ratio of the diluted n-dodecane to the tantalum-niobium acidic wastewater is 1, the extraction time is 10 min, and the phase separation time is 5 min;

[0028] (3) Distillation: distilling the organic phase containing octanol obtained in step (2) to obtain octanol product and diluted n-dodecane, and recycling the diluted n-dodecane to step (2), wherein the distillation temperature is 200° C. and the distillation time is 90 min.

[0029] The extraction rate of 2-octanol is 98.97%, and the purity of the obtained 2-octanol is 98.99%, which meets the testing requirements of the national standard GB / T9722-2023 General Rules for Gas Chromatography.

[0030] Example 3

[0031] A method for extracting and recovering sec-octanol from tantalum-niobium acid wastewater comprises the following steps:

[0032] (1) Dilution: Mix odorless kerosene and n-dodecane evenly to obtain diluted n-dodecane, wherein n-dodecane accounts for 50% of the odorless kerosene, the boiling point of the odorless kerosene is 230° C., and the homogenization time is 12 min;

[0033] (2) Extraction: adding the diluted n-dodecane obtained in step (1) to the tantalum-niobium acidic wastewater to extract the octanol, obtaining a raffinate and an organic phase containing the octanol, and centrally treating the raffinate, wherein the ratio of the diluted n-dodecane to the tantalum-niobium acidic wastewater is 0.5, the extraction time is 5 min, and the phase separation time is 9 min;

[0034] (3) Distillation: distilling the organic phase containing octanol obtained in step (2) to obtain octanol product and diluted n-dodecane, and recycling the diluted n-dodecane to step (2), wherein the distillation temperature is 210° C. and the distillation time is 100 min.

[0035] The extraction rate of 2-octanol is 99.43%, and the purity of the obtained 2-octanol is 99.28%, which meets the testing requirements of the national standard GB / T9722-2023 general rules for gas chromatography.

[0036] Example 4

[0037] A method for extracting and recovering sec-octanol from tantalum-niobium acid wastewater comprises the following steps:

[0038] (1) Dilution: odorless kerosene and n-dodecane are mixed evenly to obtain diluted n-dodecane, wherein n-dodecane accounts for 55% of the odorless kerosene, the boiling point of the odorless kerosene is 270° C., and the homogenization time is 11 min;

[0039] (2) Extraction: adding the diluted n-dodecane obtained in step (1) to the tantalum-niobium acidic wastewater to extract the octanol, obtaining a raffinate and an organic phase containing the octanol, and centrally treating the raffinate, wherein the ratio of the diluted n-dodecane to the tantalum-niobium acidic wastewater is 2, the extraction time is 6 min, and the phase separation time is 8 min;

[0040] (3) Distillation: distilling the organic phase containing octanol obtained in step (2) to obtain octanol product and diluted n-dodecane, and recycling the diluted n-dodecane to step (2), wherein the distillation temperature is 205° C. and the distillation time is 70 min.

[0041] The extraction rate of 2-octanol is 99.12%, and the purity of the obtained 2-octanol is 99.45%, which meets the testing requirements of the national standard GB / T9722-2023 general rules for gas chromatography.

[0042] Example 5

[0043] A method for extracting and recovering sec-octanol from tantalum-niobium acid wastewater comprises the following steps:

[0044] (1) Dilution: Mix odorless kerosene and n-dodecane evenly to obtain diluted n-dodecane, wherein n-dodecane accounts for 50% of the odorless kerosene, the boiling point of the odorless kerosene is 245° C., and the homogenization time is 13 min;

[0045] (2) Extraction: adding the diluted n-dodecane obtained in step (1) to the tantalum-niobium acidic wastewater to extract the octanol, obtaining a raffinate and an organic phase containing the octanol, and centrally treating the raffinate, wherein the ratio of the diluted n-dodecane to the tantalum-niobium acidic wastewater is 2, the extraction time is 10 min, and the phase separation time is 8 min;

[0046] (3) Distillation: distilling the organic phase containing octanol obtained in step (2) to obtain octanol product and diluted n-dodecane, and recycling the diluted n-dodecane to step (2), wherein the distillation temperature is 208° C. and the distillation time is 70 min.

[0047] The extraction rate of 2-octanol is 99.09%, and the purity of the obtained 2-octanol is 99.37%, which meets the testing requirements of the national standard GB / T9722-2023 General Rules for Gas Chromatography.

[0048] Comparative Example 1

[0049] A method for extracting and recovering sec-octanol from tantalum-niobium acid wastewater comprises the following steps:

[0050] (1) Dilution: Mix odorless kerosene and n-dodecane evenly to obtain diluted n-dodecane, wherein n-dodecane accounts for 40% of the odorless kerosene, the boiling point of the odorless kerosene is 180° C., and the homogenization time is 10 min;

[0051] (2) Extraction: adding the diluted n-dodecane obtained in step (1) to the tantalum-niobium acidic wastewater to extract the octanol, obtaining a raffinate and an organic phase containing the octanol, and centrally treating the raffinate, wherein the ratio of the diluted n-dodecane to the tantalum-niobium acidic wastewater is 22, the extraction time is 10 min, and the phase separation time is 8 min;

[0052] (3) Distillation: distilling the organic phase containing octanol obtained in step (2) to obtain octanol product and diluted n-dodecane, and recycling the diluted n-dodecane to step (2), wherein the distillation temperature is 220° C. and the distillation time is 70 min.

[0053] The extraction rate of 2-octanol is 99.46%, and the purity of the obtained 2-octanol is 47.21%, which meets the test requirements of the national standard GB / T9722-2023 General Rules for Gas Chromatography. The low purity is due to the boiling point of kerosene at 180°C and the boiling point of 2-octanol at 196°C. When the distillation temperature is 220°C, odorless kerosene will evaporate, resulting in low purity of 2-octanol.

[0054] Comparative Example 2

[0055] A method for extracting and recovering sec-octanol from tantalum-niobium acid wastewater comprises the following steps:

[0056] (1) Dilution: Mix odorless kerosene and n-dodecane evenly to obtain diluted n-dodecane, wherein n-dodecane accounts for 5% of the odorless kerosene, the boiling point of the odorless kerosene is 240° C., and the homogenization time is 15 min;

[0057] (2) Extraction: adding the diluted n-dodecane obtained in step (1) to the tantalum-niobium acidic wastewater to extract the octanol, obtaining a raffinate and an organic phase containing the octanol, and centrally treating the raffinate, wherein the ratio of the diluted n-dodecane to the tantalum-niobium acidic wastewater is 2, the extraction time is 8 min, and the phase separation time is 9 min;

[0058] (3) Distillation: distilling the organic phase containing octanol obtained in step (2) to obtain octanol product and diluted n-dodecane, and recycling the diluted n-dodecane to step (2), wherein the distillation temperature is 205° C. and the distillation time is 80 min.

[0059] The extraction rate of 2-octanol was 42.31%, and the purity of the obtained 2-octanol was 98.91%, which met the test requirements of the national standard GB / T9722-2023 General Rules for Gas Chromatography. The main reason for the low extraction rate is that n-dodecane accounts for only 5% of odorless kerosene, and n-dodecane is diluted by odorless kerosene, resulting in low extraction capacity.

[0060] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A method for extracting and recovering 2-octanol from tantalum-niobium acidic wastewater, wherein the tantalum-niobium acidic wastewater refers to the acidic wastewater generated during the extraction of tantalum-niobium using 2-octanol, characterized in that: The steps include: S1, dilution: mixing odorless kerosene and n-dodecane in a certain proportion to obtain diluted n-dodecane; S2, extraction: adding the diluted n-dodecane obtained in S1 to the tantalum-niobium acid wastewater to extract the secondary octanol, obtaining a raffinate and an organic phase containing the secondary octanol, and centrally treating the raffinate; S3, distillation: distilling the organic phase containing sec-octanol obtained in S2 to obtain sec-octanol product and diluted n-dodecane, and the diluted n-dodecane is recycled to S2.

2. The method according to claim 1, characterized in that: During the dilution process, n-dodecane accounts for 20-60% of the odorless kerosene, wherein the boiling point of the odorless kerosene is 195-300° C., and the homogenization time is 5-15 minutes.

3. The method according to claim 1, characterized in that: During the extraction process, the ratio of diluted n-dodecane to tantalum-niobium acid wastewater is 2-0.5, the extraction time is 3-10 minutes, and the phase separation time is 4-10 minutes.

4. The method according to claim 1, characterized in that: During the distillation process, the distillation temperature is 180-210°C and the distillation time is 30-100min.

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