Preparation method of high dispersion cuprous oxide

Abstract

This invention provides a method for preparing highly dispersed cuprous oxide. Copper oxide particles are added to a sulfite solution in a sealed reaction vessel, and stirring is initiated. The mixture is then heated to 100-150°C, and an acid solution is slowly added until the final pH reaches 7.5-8.5. The acid solution is added over 1-3 hours. After the acid solution is added, the reaction is continued with stirring for 30-60 minutes. After cooling, the mixture is filtered, washed, and dried to obtain cuprous oxide particles. This invention uses a high-temperature hydrothermal method to obtain copper oxide particles based on copper-ammonia complex ions. At high temperatures, the gradual volatilization of ammonia causes copper ions to gradually dissociate, which are then hydrolyzed to obtain copper oxide particles with high uniformity and dispersibility. These particles are then further reduced in a high-temperature aqueous solution environment to obtain cuprous oxide particles, resulting in high dispersibility and uniformity. Furthermore, this invention uses copper smelting furnace ash as a raw material, significantly reducing costs.

Description

Technical Field

[0001] This invention relates to the field of materials technology, and specifically to a method for preparing highly dispersed cuprous oxide. Background Technology

[0002] Cuprous oxide is an oxide-type inorganic compound with the chemical formula Cu₂O. It appears as a red or orange-red powder with a density of 6.0 g / cm³. 3 In humid air, cuprous oxide can be slowly oxidized to copper oxide. When heated in air, it can decompose into copper and oxygen. It can be reduced to metallic copper by reducing agents such as hydrogen and carbon monoxide.

[0003] Cuprous oxide can be prepared by two methods: the glucose reduction method and the dry method. The glucose reduction method involves adding a glucose solution to a copper sulfate solution, followed by the addition of a clear sodium hydroxide solution. The dry method involves calcining copper powder with copper oxide to produce cuprous oxide. In manufacturing, cuprous oxide is used to make red pigments for glass and enamel, as well as antifouling paint for ship hulls. It is also used as an analytical reagent and in the manufacture of various copper salts. Furthermore, it is used in electroplating for rectification in the electrical manufacturing industry. In agriculture, cuprous oxide can be used as a fungicide for crops. Cuprous oxide is also frequently used as a catalyst in the synthesis of organic compounds.

[0004] The dispersibility of cuprous oxide used as a catalyst is crucial, as highly dispersed cuprous oxide can make the catalytic effect more stable and efficient.

[0005] However, current conventional processes, whether the glucose reduction method or the dry method for preparing cuprous oxide, struggle to produce highly dispersed cuprous oxide. The glucose reduction method directly uses copper sulfate solution to prepare cuprous oxide. Because the liquid-phase synthesis process, based on a divalent copper ion solution, involves steps similar to ordinary liquid-phase precipitation, including nucleation and growth, it easily leads to particle agglomeration, making it difficult to obtain highly dispersed cuprous oxide particles. The dry method for preparing cuprous oxide, requiring high-temperature sintering, also makes it difficult to obtain highly dispersed materials with small primary particle sizes. Summary of the Invention

[0006] To address the shortcomings of existing technologies, this invention proposes a high-temperature hydrothermal method for obtaining copper oxide particles. This method utilizes copper-ammonia complex ions as a base. At high temperatures, the gradual volatilization of ammonia causes copper ions to gradually dissociate, leading to hydrolysis and the production of copper oxide particles. Because the copper ions are released slowly, the particles exhibit high uniformity and dispersibility. These copper oxide particles are then further reduced in a high-temperature aqueous solution to obtain cuprous oxide particles. Since this invention first prepares copper oxide particles with high uniformity and dispersibility, and then uses these as a template for reduction with a reducing solution, cuprous oxide particles are obtained. Furthermore, this invention uses copper smelting furnace ash as a raw material, significantly reducing costs.

[0007] The present invention adopts the following technical solution:

[0008] This invention proposes a method for preparing highly dispersed cuprous oxide. Copper oxide particles are added to a sulfite solution and placed in a sealed reaction vessel. Stirring is initiated, and the mixture is heated to 100-150°C. An acid solution is then slowly added, maintaining a final pH of 7.5-8.5 over 1-3 hours. After the acid solution is added, stirring continues for 30-60 minutes. The mixture is then cooled, filtered, washed, and dried to obtain cuprous oxide particles. This invention uses copper oxide particles as a template and operates in a reducing solution to avoid agglomeration during the formation of cuprous oxide particles.

[0009] This invention also proposes a method for preparing copper oxide, using copper smelting furnace ash as raw material. Its main components are copper, zinc, lead, tin, etc. Using this waste or by-product as raw material is inexpensive. Ammonia water is added, and after stirring and slurrying, hydrogen peroxide is added and stirred and dissolved thoroughly. Under the action of oxidant and ammonia water, copper will form copper-ammonia complex ions, thereby selectively leaching copper ions. The dissolution temperature is 30-60℃. Because if the temperature is too low, the copper leaching rate will be low, and if the temperature is too high, the ammonia volatilization rate will be too fast, which is not conducive to copper leaching. The copper-ammonia complex ion solution is obtained and stirred and reacted at a temperature of 110-150℃ for 2-4 hours. Under high temperature conditions, ammonia will gradually volatilize, causing copper ions to dissociate. Then, high-temperature hydrolysis is performed to obtain copper oxide particles. Using this process, the copper ions can be gradually and slowly released, thereby controlling the rate of copper oxide production by hydrolysis. This avoids rapid nucleation and growth, which causes large fluctuations in the primary particle size, and greatly improves the uniformity of the particle size of the material.

[0010] In the copper oxide reduction process, the molar ratio of copper oxide to sulfite is 1:0.510-0.550, the concentration of the sulfite solution is 1.0-3.0 mol / L, and the stirring speed is 150-500 r / min. Under stirring, the copper oxide is dispersed in the sulfite solution. Through the reducing property of sulfite, copper ions are reduced to cuprous ions. In order to enhance the reducing property of sulfite, an acid solution is also added to adjust the pH of the solution and control the pH to a near-neutral environment. Under this environment, the dissolution and disproportionation of cuprous ions are avoided, resulting in higher purity cuprous oxide.

[0011] The selected sulfite is at least one of sodium sulfite, potassium sulfite, and ammonium sulfite, all of which are water-soluble and have relatively high solubility.

[0012] Drying is performed using vacuum drying or nitrogen protection at a temperature of 80-150℃. Drying is stopped when the moisture content is below 0.03wt%. The presence of oxygen must be avoided, as it can cause oxidation during the drying process, thus reducing the purity of cuprous oxide.

[0013] Before reducing copper oxide particles, the copper oxide particles need to be crushed to a particle size of D50 of 0.5-3μm and D100≤15μm. This allows the copper oxide to be reduced more thoroughly and the reduction reaction to be more efficient.

[0014] When dissolving copper fume, ammonia solution with a concentration of 1.5-3.0 mol / L is used. The molar ratio of copper in the copper fume to ammonia in the added ammonia solution is 1:8-12. The molar ratio of hydrogen peroxide to copper in the copper fume is 1.2-1.5:1. The hydrogen peroxide is added over 1-3 hours. After adding the hydrogen peroxide, the reaction is stirred for another 30-60 minutes. Because hydrogen peroxide decomposes rapidly under alkaline conditions, it needs to be added slowly to oxidize the copper fume.

[0015] When the copper ammonia complex solution is reacted in a high-pressure reactor, the stirring speed is 150-350 r / min. During the stirring process, the solution can be homogenized, and particle agglomeration can be avoided.

[0016] This invention uses copper ash as raw material, which is low-cost and enables the resource utilization of waste. Simultaneously, this invention uses ammonia water and an oxidant as leaching agents to selectively leach out copper elements. Then, a spray pyrolysis method is used to obtain copper oxide particles. Subsequently, a reduction reaction is carried out at high temperature to reduce the copper oxide particles to cuprous oxide particles. The cuprous oxide particles prepared using this process exhibit high dispersibility and uniformity.

[0017] The preparation of cuprous oxide using this process has the following advantages:

[0018] 1. Using copper flue ash waste as raw material can not only process waste and avoid environmental pollution, but also obtain cuprous oxide with high added value, achieving two goals at a low cost.

[0019] 2. The process of the present invention prepares copper oxide particles through high-temperature pyrolysis, and then uses these particles as a template to prepare cuprous oxide by adding a reducing agent. The resulting particles have uniform particle size and good dispersibility.

[0020] 3. This invention uses copper ash as raw material and employs oxidation + ammonia leaching, avoiding the use of sulfuric acid, hydrochloric acid, etc., which introduces anions and results in a high anion content in the product. Furthermore, the selective leaching of oxidation + ammonia can effectively prevent the leaching of metal impurity ions, thereby making the metal ion impurity content of the product relatively low. Attached Figure Description

[0021] To more clearly illustrate the technical solutions of this application, the accompanying drawings used in this application will be briefly described below. Obviously, the drawings described below are merely some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without any creative effort.

[0022] Figure 1 This is a SEM image of cuprous oxide from Example 1 of the present invention. Detailed Implementation

[0023] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0024] The present invention will now be described in further detail with reference to specific embodiments.

[0025] Example 1: First, copper oxide was prepared. The preparation method was to use copper smelting furnace flue gas. The test results are as follows:

[0026]

[0027] The above-mentioned soot was added to ammonia water with a concentration of 2.3 mol / L. The molar ratio of copper in the copper soot to ammonia in the added ammonia water was 1:10. After stirring and slurrying, hydrogen peroxide with a concentration of 1.0 mol / L was added. The molar ratio of hydrogen peroxide added to copper in the copper soot was 1.35:1. The hydrogen peroxide was added over a period of 2 hours at a dissolution temperature of 30°C. After the hydrogen peroxide was added, the reaction was stirred for another 45 minutes. The mixture was then filtered to obtain a copper-ammonia complex ion solution.

[0028] The copper oxide was added to a reaction vessel and heated to 130℃ with a stirring speed of 250 r / min. The mixture was stirred and reacted for 3 hours, then filtered. The resulting filter residue was washed with pure water until the conductivity of the washing water was ≤150 μS / cm. Washing was then stopped, and the residue was dried until the moisture content of the copper oxide particles was below 0.05 wt%. The residue was then pulverized to a particle size of D50 of 1.7 μm and D100 of 13.8 μm. The detection data of the obtained copper oxide particles are as follows:

[0029]

[0030] The copper oxide particles were added to a sodium sulfite solution at a molar ratio of 1:0.535, with a sodium sulfite concentration of 2.0 mol / L. The mixture was placed in a sealed reactor, and stirring was started at 325 r / min. The temperature was then raised to 125°C, and a 1.0 mol / L acetic acid solution was slowly added until the final pH reached 8.0. The acid solution was added over a period of 2.0 h. After the acid solution was added, the reaction was stirred for another 45 min. The mixture was then cooled to below 90°C, filtered, and washed until the conductivity of the wash water was ≤200 μS / cm. The washed material was then dried under vacuum at 95°C until the moisture content was below 0.03 wt%. The dried material was then sieved through a 200-mesh vibrating screen and vacuum-packed to obtain cuprous oxide particles.

[0031] The detection data for cuprous oxide obtained are as follows:

[0032]

[0033] SEM images of the obtained cuprous oxide are as follows: Figure 1 As shown in the above physicochemical data, the cuprous oxide obtained by this invention has a very high purity, reaching 99.78%, and the anion content of this invention is very low. Figure 1 As shown, the cuprous oxide particles of the present invention have high dispersibility and a relatively concentrated primary particle size distribution.

[0034] Example 2: First, copper oxide was prepared. The preparation method was as follows: copper smelting furnace flue dust was added to ammonia water with a concentration of 1.5 mol / L. The molar ratio of copper in the copper flue dust to ammonia in the added ammonia water was 1:8. After stirring and slurry formation, hydrogen peroxide with a concentration of 1.0 mol / L was added. The molar ratio of hydrogen peroxide to copper in the copper flue dust was 1.20:1. The hydrogen peroxide was added over a period of 1 hour at a dissolution temperature of 45°C. After the hydrogen peroxide was added, the reaction was continued with stirring for 45 minutes. After filtration, a copper-ammonia complex solution was obtained and added to a reaction vessel. The temperature was raised to 120℃, and the stirring speed was 200 r / min. The reaction was carried out at this temperature for 2 hours, followed by filtration. The filter residue was washed with pure water until the conductivity of the washing water was ≤150 μS / cm. Washing was then stopped. The residue was dried until the moisture content of the copper oxide particles was less than 0.05 wt%. The residue was then pulverized to a particle size of D50 of 0.5 μm and D100 of 11.3 μm. The detection data of the obtained copper oxide particles are as follows:

[0035]

[0036] The copper oxide particles were added to a sodium sulfite solution at a molar ratio of 1:0.510, with a sodium sulfite concentration of 1.0 mol / L. The mixture was placed in a sealed reactor, and stirring was started at 300 r / min. The temperature was then raised to 110℃, and 0.8 mol / L acetic acid solution was slowly added until the final pH reached 7.5. The acid solution was added over 1.5 h. After the acid solution was added, the reaction was continued with stirring for 45 min. The mixture was then cooled to below 90℃, filtered, and washed until the conductivity of the wash water was ≤200 μS / cm. The washed material was then dried under vacuum at 95℃ until the moisture content was below 0.03 wt%. The dried material was then sieved through a 200-mesh vibrating screen and vacuum-packed to obtain cuprous oxide particles. The test data are as follows:

[0037]

[0038] Example 3: First, copper oxide was prepared. The preparation method was as follows: copper smelting furnace flue dust was added to ammonia water with a concentration of 3.0 mol / L. The molar ratio of copper in the copper flue dust to ammonia in the added ammonia water was 1:12. After stirring and slurry formation, hydrogen peroxide with a concentration of 1.5 mol / L was added. The molar ratio of hydrogen peroxide to copper in the copper flue dust was 1.50:1. The hydrogen peroxide was added over a period of 3 hours at a dissolution temperature of 60°C. After the hydrogen peroxide was added, the reaction was stirred for another 60 minutes. After filtration, a copper-ammonia complex solution was obtained and added to a reaction vessel. The temperature was raised to 150℃, and the stirring speed was 500 r / min. The reaction was carried out at this temperature for 4 hours, followed by filtration. The filter residue was washed with pure water until the conductivity of the washing water was ≤150 μS / cm. Washing was then stopped. The residue was dried until the moisture content of the copper oxide particles was less than 0.05 wt%. The residue was then pulverized to a particle size of D50 of 3.0 μm and D100 of 15.0 μm. The detection data of the obtained copper oxide particles are as follows:

[0039]

[0040] The copper oxide particles were added to a sodium sulfite solution at a molar ratio of 1:0.550, with a sodium sulfite concentration of 3.0 mol / L. The mixture was placed in a sealed reactor, and stirring was started at 500 rpm. The temperature was then raised to 150°C, and a 1.5 mol / L acetic acid solution was slowly added until the final pH reached 8.5. The acid solution was added over 3.0 h. After the acid solution was added, the reaction was continued with stirring for 45 min. The mixture was then cooled to below 90°C, filtered, and washed until the conductivity of the wash water was ≤200 μS / cm. The washed material was then dried under nitrogen protection, maintaining an oxygen content below 20 ppm in the drying oven at 150°C. Drying was stopped when the moisture content was below 0.03 wt%. The dried material was then sieved through a 200-mesh vibrating screen and vacuum-packed to obtain cuprous oxide particles. The test data are as follows:

[0041]

[0042] Example 4: The process was the same as in Example 1, except that acetic acid solution was added to make the pH 7.7. The final detection data of cuprous oxide are as follows:

[0043]

[0044] Example 5: The process was the same as in Example 1, except that acetic acid solution was added to make the pH 8.3. The final detection data of cuprous oxide are as follows:

[0045]

[0046] Comparative Example 1: The process was the same as in Example 1, except that acetic acid solution was added to make the pH 7.2. The final detection data of cuprous oxide are as follows:

[0047]

[0048] When the pH is too low, although the impurity content of cuprous oxide is low, the excessively low pH will cause cuprous ions to dissolve and disproportionate, thereby forming copper ions and elemental copper, resulting in a decrease in the purity of cuprous oxide.

[0049] Comparative Example 2: The process was the same as in Example 1, except that acetic acid solution was added to make the pH 8.7. The final detection data of cuprous oxide are as follows:

[0050]

[0051] When the pH is too high, a large number of impurity ions precipitate out, and the impurity content of cuprous oxide is high. Furthermore, because the pH is too high, the reducing power of sodium sulfite is too weak, resulting in incomplete reduction of the copper oxide particles and low purity of cuprous oxide.

[0052] The particle size of Examples 1-5, as well as Comparative Examples 1 and 2, was measured using a laser particle size analyzer and simultaneously measured using SEM. The primary particle size was calculated, and the ratio of the laser particle size analyzer's D50 to the average primary particle size obtained from the SEM was used. The closer the obtained data is to 1, the better the dispersibility. The test data are as follows:

[0053]

[0054] Based on the data above, its dispersibility increases at both excessively high and excessively low pH levels.

[0055] The detection method for the main content of cuprous oxide is as described in HG / T 2961-2010, and the detection methods for chloride ions, moisture, and metallic impurities are also described in HG / T 2961-2010. BET is tested using the nitrogen adsorption method. S is tested using a carbon-sulfur analyzer.

[0056] It should be noted that this application is not limited to the above-described embodiments. The above embodiments are merely examples, and any embodiments with the same structure and effect as the technical concept within the scope of this application are included in the technical scope of this application. Furthermore, various modifications that can be conceived by those skilled in the art to the embodiments, and other ways of constructing by combining some of the constituent elements of the embodiments, without departing from the spirit of this application, are also included in the scope of this application.

Claims

1. A process for the preparation of highly dispersed cuprous oxide, characterized in that: Add copper oxide particles to a sulfite solution, place the mixture in a sealed reaction vessel, start stirring, and then heat to 100-150℃. Slowly add an acid solution to bring the final pH to 7.5-8.

5. The acid solution is added over 1-3 hours. After the acid solution is added, continue stirring for 30-60 minutes. Then cool, filter, wash, and dry to obtain cuprous oxide particles. The method for preparing the copper oxide particles is as follows: copper smelting furnace flue ash is added to ammonia water, stirred and slurried, hydrogen peroxide is added, and the mixture is stirred and dissolved thoroughly at a temperature of 30-60℃. The mixture is then filtered to obtain a copper ammonia complex ion solution, which is added to a reaction vessel and heated to a temperature of 110-150℃. The mixture is stirred and reacted at this temperature for 2-4 hours, and then filtered. The filter residue is washed to obtain copper oxide particles. The molar ratio of added copper oxide to sulfite is 1:0.510-0.550, the concentration of the sulfite solution is 1.0-3.0 mol / L, the stirring speed during the reaction is 150-500 r / min, the sulfite is at least one of sodium sulfite, potassium sulfite, and ammonium sulfite, the acid solution is at least one of sulfuric acid, hydrochloric acid, and acetic acid, and its concentration is 0.5-1.5 mol / L, washing is performed until the conductivity of the washing water is ≤200 μS / cm, drying is carried out by vacuum drying or nitrogen protection, the drying temperature is 80-150℃, drying is stopped when the moisture content is lower than 0.03wt%, the dried material is sieved through a 100-300 mesh vibrating screen and then vacuum packaged. The concentration of ammonia water is 1.5-3.0 mol / L, the molar ratio of copper in copper flue dust to ammonia in the added ammonia water is 1:8-12, the molar ratio of hydrogen peroxide added to copper in copper flue dust is 1.2-1.5:1, the hydrogen peroxide is added over 1-3 hours, and the reaction is continued for 30-60 minutes after the hydrogen peroxide is added.

2. The method for preparing highly dispersed cuprous oxide according to claim 1, characterized in that, The copper oxide particles are pulverized to a particle size D50 of 0.5-3μm and D100 ≤ 15μm.

3. The method for preparing highly dispersed cuprous oxide according to claim 1, characterized in that, When the copper ammonia complex solution is reacted in a high-pressure reactor, the stirring speed is 150-350 r / min. After the reaction is completed, the filter residue is washed until the conductivity of the washing water is ≤150 μS / cm and then the washing is stopped. Then the copper oxide particles are dried until the moisture content is less than 0.05 wt% and then the drying is stopped.

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