Hollow spherical copper hydroxide and its preparation method

Abstract

This application provides a hollow spherical copper hydroxide and its preparation method. The preparation method includes: mixing seed crystals and water uniformly to obtain a seed crystal dispersion, wherein the seed crystals include hydrochloric acid-catalyzed basic copper chloride; adding purified acidic copper-containing etching waste liquid, ammonia, and a stabilizer to the seed crystal dispersion to obtain a mixed reactant with a pH of 4-5.5; heating the mixed reactant at a temperature of 40-80°C and stirring at a stirring speed of 100-200 r / min; separating the solid substance after the reaction and drying it to obtain an intermediate, wherein the intermediate includes spherical basic copper chloride; mixing the intermediate and a solvent uniformly to obtain an intermediate dispersion; adding ammonia to the intermediate dispersion and stirring, wherein the mass ratio of the intermediate to the ammonia is 1:1.05-1:1.15; separating the deposit after the reaction, washing, and drying it to obtain the hollow spherical copper hydroxide.

Description

Technical Field

[0001] This application relates to the technical field of copper hydroxide preparation, and more particularly to a hollow spherical copper hydroxide and its preparation method. Background Technology

[0002] Copper hydroxide, with the molecular formula Cu(OH)₂, appears as blue granules. It is sparingly soluble in water, slightly amphoteric, soluble in acids and ammonia, darkens in color upon heating, and decomposes at high temperatures into black copper oxide and water. It is commonly used as an analytical reagent, has applications in the pharmaceutical field, and can also be used as a raw material to prepare copper hydroxide preparations for use in pesticides and fungicides.

[0003] The conventional method for preparing copper hydroxide involves reacting a solution containing copper ions (such as copper chloride solution or copper sulfate solution) with alkaline substances like sodium hydroxide or potassium hydroxide, precipitating the product, and collecting the precipitate. However, because copper hydroxide is a heat-sensitive compound, the acid-base neutralization precipitation reaction involving strong alkaline substances like sodium hydroxide and potassium hydroxide is exothermic and violent. This results in copper hydroxide produced industrially using conventional methods often being amorphous, even muddy, with a dark or blackish color, low purity, and difficult to mass-produce, thus reducing its application value. Summary of the Invention

[0004] In view of this, this application provides a hollow spherical copper hydroxide and a method for preparing the same.

[0005] To achieve the above objectives, this application provides a method for preparing hollow spherical copper hydroxide. The method includes: mixing seed crystals and water uniformly to obtain a seed crystal dispersion, wherein the seed crystals include hydrochloric acid-catalyzed basic copper chloride; adding purified acidic copper-containing etching waste liquid, ammonia, and a stabilizer to the seed crystal dispersion to obtain a mixed reactant with a pH of 4–5.5; heating the mixed reactant at a temperature of 40–80°C and stirring it at a stirring speed of 100–200 r / min; separating the solid substance after the reaction and drying it to obtain an intermediate, wherein the intermediate includes spherical basic copper chloride.

[0006] The intermediate and solvent are mixed evenly to obtain an intermediate dispersion; ammonia is added to the intermediate dispersion and stirred, the mass ratio of the intermediate to the ammonia is 1:1.05 to 1:1.15; after the reaction, the precipitate is separated, washed, and dried to obtain the hollow spherical copper hydroxide.

[0007] In some possible implementations, the reaction temperature of the intermediate dispersion and the ammonia water is 40–60°C.

[0008] In some possible implementations, the stirring speed for the reaction of the intermediate dispersion and the ammonia is 50–100 r / min.

[0009] In some possible implementations, the mass ratio of the intermediate to the solvent is 1:1 to 2:1.

[0010] In some possible implementations, the ammonia solution has a mass fraction of 15-30%.

[0011] In some possible implementations, the reaction time between the intermediate dispersion and the ammonia water is 0.5 h to 2 h.

[0012] In some possible implementations, the solvent is water or a base liquid, which is the liquid recovered from washing the sediment.

[0013] In some possible implementations, the temperature for drying the sediment is 50–105°C.

[0014] This application also provides a hollow spherical copper hydroxide, prepared according to a preparation method.

[0015] In some possible embodiments, the hollow spherical copper hydroxide includes a hollow portion that occupies 1 / 4.5 to 1 / 3.5 of the total volume of the hollow spherical copper hydroxide.

[0016] In the preparation of the spherical basic copper chloride intermediate, this application uses hydrochloric acid to catalyze the basic copper chloride as a seed crystal. Copper and ammonia react in an acidic copper-containing etching waste solution, and the reaction product rapidly grows on the seed crystal surface to form crystals. The crystals continuously grow to form spherical basic copper chloride. During the crystal growth process, the reaction temperature is controlled to control the growth rate of the seed crystal, and the stirring speed is controlled to control the crystal morphology, thereby controlling the crystal growth and transforming the irregular surface of the crystal into a regular spherical shape, thus obtaining spherical basic copper chloride. Furthermore, the continuous stirring process grinds the crystal surface, strengthening the structural strength of the crystal, resulting in a smooth surface and good overall structural stability and high hardness of the final crystal. The spherical basic copper chloride prepared in this application has a particle size between 50 and 100 μm and a purity of up to 99%. Then, the intermediate dispersion containing spherical basic copper chloride and ammonia water are mixed in a certain proportion and reacted. Some of the copper and chlorine elements in the spherical basic copper chloride combine with the ammonia water to form a liquid-phase diamminecopper chloride [Cu(NH3)2Cl2] complex, which enters the solution, thereby converting the spherical basic copper chloride into hollow spherical copper hydroxide. The preparation method of this application is simple and controllable, conducive to large-scale production. The particle size is 5–200 μm, the purity is above 98%, and the stability is good, remaining unchanged in color and without clumping for up to 1.5 years. Furthermore, the prepared hollow spherical copper hydroxide has a large specific surface area, making it widely applicable in dyeing, sterilization, or catalyst fields. Attached Figure Description

[0017] Figure 1 This is an X-ray diffraction pattern of the intermediate prepared in Example 1 of this application.

[0018] Figure 2 The image shows the X-ray diffraction pattern of the hollow spherical copper hydroxide prepared in Example 1 of this application.

[0019] Figure 3 This is a microscope image of the intermediate prepared in Example 1 of this application, magnified 200 times.

[0020] Figure 4 This is a microscope image of the intermediate prepared in Comparative Example 1 of this application, magnified 200 times.

[0021] Figure 5 This is a microscope image of the intermediate prepared in Comparative Example 2 of this application, magnified 200 times.

[0022] Figure 6 This is a 200x magnified microscope image of the hollow spherical copper hydroxide prepared in Example 1 of this application.

[0023] Figure 7 This is a 200x magnified microscopic image of the cross-section of the hollow spherical copper hydroxide prepared in Example 1 of this application. Detailed Implementation

[0024] Embodiments of the present invention are described in detail below. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0025] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0026] Acidic copper-containing etching waste liquid is the etching waste liquid discharged after etching printed circuit boards (PCBs). It contains a large amount of copper chloride, hydrochloric acid and a small amount of ammonium chloride.

[0027] This application provides a method for preparing hollow spherical copper hydroxide, the method comprising:

[0028] S1. Mix the seed crystals and water evenly to obtain a seed crystal dispersion, wherein the seed crystals include hydrochloric acid-catalyzed basic copper chloride.

[0029] Specifically, this step may involve adding water and seed crystals to a reactor, stirring, and obtaining the seed crystal dispersion. The water should occupy approximately 1 / 5 of the reactor volume, and the mixture should be stirred thoroughly to ensure that the seed crystals are uniformly dispersed in the water.

[0030] Hydrochloric acid-catalyzed basic copper chloride is a product obtained by the chemical catalytic efflorescence of crystalline basic copper chloride with hydrochloric acid, causing the crystalline particles to expand and break apart. Hydrochloric acid-catalyzed basic copper chloride is insoluble in water; therefore, seed crystals are added to water and stirred thoroughly to ensure uniform dispersion, which facilitates subsequent reactions.

[0031] The preparation method of hydrochloric acid-catalyzed basic copper chloride is existing technology, and can be found in patent number 200810218161.2, which will not be elaborated here. In this embodiment, the hydrochloric acid-catalyzed basic copper chloride is preferably prepared using the preparation method of Example 1 in the aforementioned patent. The difference between this embodiment and Example 1 is that the acetic acid in Example 1 is replaced with hydrochloric acid, while other conditions remain unchanged, to obtain the prepared hydrochloric acid-catalyzed efflorescent basic copper chloride product.

[0032] The aforementioned hydrochloric acid-catalyzed basic copper chloride has a rough surface with depressions and small crystal particles. Basic copper chloride crystals exist in various types, and the microstructure and stability of basic copper chloride prepared using different crystal forms as seed crystals differ, and they can also interconvert under certain conditions. In this application, hydrochloric acid-catalyzed basic copper chloride is used as a seed crystal, which facilitates the formation of stable spherical basic copper chloride during subsequent crystal growth and ensures that the subsequent crystals grow into uniformly sized crystals.

[0033] S2. Add the purified acidic copper-containing etching waste liquid, ammonia, and stabilizer to the seed dispersion to obtain a mixed reactant with a pH of 4 to 5.5.

[0034] In this process, since the acidic copper-containing etching waste liquid is highly acidic, the addition of ammonia can adjust the pH of the reaction, and the reaction can be controlled and kept mild, which is beneficial for treating the wastewater from the subsequent preparation of spherical basic copper chloride in this application. At the same time, ammonia is also added as a reactant, which is inexpensive and readily available. In some embodiments, the pH can be 4, 4.5, 5, or 5.5.

[0035] Acidic copper-containing etching waste liquid refers to the acidic etching waste liquid of printed circuit boards, which contains copper ions and chloride ions. In some embodiments, the acidic copper-containing etching waste liquid after impurity removal refers to the acidic copper-containing etching waste liquid obtained after removing impurities including but not limited to dioxins, arsenic, lead, cadmium and insoluble solids.

[0036] The impurity removal step of the acidic copper-containing etching waste liquid is an existing technology. For details, please refer to the records of patent numbers 200810141671.4 and 201010567599.9. It will not be elaborated here.

[0037] S3. The mixed reactants are heated to a temperature of 40–80°C and stirred at a speed of 100–200 r / min. After the reaction, the solid substance is separated, dried, and an intermediate is obtained, which includes spherical basic copper chloride. The main chemical reactions occurring in this step are:

[0038] 2CuCl2+3NH3·H2O=Cu2(OH)3Cl+3NH4Cl

[0039] Through the above reaction, Cu2(OH)3Cl is grown on the surface of basic copper chloride seed crystals catalyzed by hydrochloric acid and crystallized to form spherical basic copper chloride.

[0040] Using hydrochloric acid as a catalyst, basic copper chloride is used as a seed crystal. Copper and ammonia react in acidic copper-containing etching waste liquid, and the reaction product rapidly grows on the seed crystal surface to form crystals. The crystals continue to grow, and the overall structure of the crystals is stabilized by a stabilizer to obtain stable spherical basic copper chloride. During the crystal growth process, the reaction temperature is controlled to control the crystal growth rate, and the crystal morphology is controlled by controlling the stirring speed, thereby controlling the crystal growth and transforming the irregular surface of the crystals into regular spherical shapes, thus obtaining spherical basic copper chloride. Furthermore, the continuous stirring process grinds the crystal surface, strengthening the structural strength of the crystals, resulting in a smooth surface and good overall structural stability and high hardness of the final crystals. The spherical basic copper chloride prepared in this application has a particle size between 50 and 100 μm and a purity of up to 99%. It can be used as a raw material for the production of downstream copper salt products (such as copper hydroxide or copper chloride), as well as a copper source for feed additives and inorganic copper preparations in pesticides (such as copper hydroxide). Meanwhile, the spherical basic copper chloride prepared in this application has a stable structure, is resistant to storage, has good dispersibility, and good structural uniformity.

[0041] In the above preparation process, the reaction temperature and stirring speed affect the formation of spherical basic copper chloride crystals. The reaction product Cu2(OH)3Cl crystallizes and grows on the seed crystal surface, a process of wear down the irregular surface of the crystal to a regular spherical surface. Under suitable reaction temperature conditions, crystal growth is favorable for forming spherical basic copper chloride. Controlling the stirring speed during crystal growth controls the wear rate on the crystal surface, thus achieving a balance between the crystal growth rate and the wear rate, resulting in smooth-surfaced spherical basic copper chloride. In actual production, if the crystal growth rate is less than the wear rate, the resulting crystal will have an irregular morphology and poor overall structural stability due to insufficient wear on the crystal surface. Therefore, during crystal growth, it is necessary to control the crystal growth rate to ensure it does not exceed the wear rate.

[0042] In this embodiment, the reaction temperature is 40–80°C. If the reaction temperature is too high, such as above 80°C, the crystal growth and aging will accelerate, the crystal hardness will increase, and the wear rate on the crystal surface will be relatively reduced. If the reaction temperature is too low, such as below 40°C, it will affect the crystal growth rate, making it difficult for the crystal to form a spherical shape. In some embodiments, the reaction temperature can be 40°C, 45°C, 50°C, 55°C, 60°C, 70°C, or 80°C.

[0043] In this embodiment, the stirring speed is 100–200 r / min. If the stirring speed is too low, such as less than 100 r / min, the stirring speed is insufficient, the probability of contact wear between crystals decreases, and the wear rate of the crystals is reduced to a certain extent, eventually leading to the formation of basic copper chloride with other morphologies. If the stirring speed is too high, the wear on the crystal surface is greater, making it more difficult to deposit spherical basic copper chloride of a certain particle size on the crystal surface. In some embodiments, the stirring speed is 100 r / min, 120 r / min, 140 r / min, 150 r / min, 160 r / min, 180 r / min, or 200 r / min.

[0044] In some embodiments, the flow ratio of the acidic copper-containing etching waste liquid to the ammonia solution is 2:1 to 6:1, the concentration of copper ions in the acidic copper-containing etching waste liquid is 80 to 150 g / L, and the mass fraction of the ammonia solution is 15% to 30%. Under the above-mentioned suitable flow ratio, concentration, and mass fraction, the copper in the acidic copper-containing etching waste liquid can be fully reacted with the ammonia solution, and excessive ammonia solution can be avoided. In some embodiments, the flow ratio of the acidic copper-containing etching waste liquid to the ammonia solution is 2:1, 3:1, 4:1, 5:1, or 6:1. The concentration of copper ions is 80 g / L, 90 g / L, 100 g / L, 110 g / L, 120 g / L, or 150 g / L. The mass fraction of the ammonia solution is 15%, 20%, 25%, or 30%.

[0045] In some embodiments, the content of the seed crystals in the mixed reactants is 50–150 kg / m³. 3 Based on the amounts of acidic copper-containing etching waste liquid and ammonia added, within such a range, the reaction products are grown in the seed crystal. In some embodiments, the seed crystal content is 50 kg / m³. 3 60kg / m 3 80kg / m 3 100kg / m 3 120kg / m 3 130kg / m 3 Or 150kg / m 3 In some embodiments, the seed crystals have a particle size of 0.1 μm-50 μm.

[0046] In some embodiments, the flow rate of the acidic copper-containing etching waste solution added is 2–3 m / s. 3 Within this flow rate range, and by correspondingly controlling the flow rate of ammonia water, the acidic copper-containing etching waste liquid and ammonia water can be fully reacted. Simultaneously, this facilitates the integration of the entire preparation reaction process with other reaction conditions such as temperature and stirring rate to control the morphology of the reaction product and avoid uncontrollable product growth due to excessively high flow rates. In some embodiments, the flow rate is 2 m / h. 3 / h, 2.5m 3 / h, 2.8m 3 / h or 2m 3 / h.

[0047] In some embodiments, the reaction time is 2–8 hours to maintain a certain crystal growth rate in the reactor. The reaction time is inversely proportional to the concentrations of the acidic basic copper chloride waste liquid and ammonia. Unlike other layered growth methods for basic copper chloride, the crystal growth of spherical basic copper chloride belongs to a diamond-like spherical structure growth method, which places extremely high demands on the crystal growth rate. When the growth rate is too fast, the deposition rate on the crystal surface is too rapid, and the growth method will become a layered growth method, easily forming other crystal forms of basic copper chloride, resulting in irregular morphologies such as serrated edges on the crystal surface. Therefore, it is necessary to control the crystal growth rate by controlling the flow rate of the acidic basic copper chloride waste liquid, the flow rate of the ammonia, and the reaction time.

[0048] In some embodiments, during the reaction process, the growth rate of spherical basic copper chloride is less than 2 μm / h, and the crystal growth rate is controlled to not exceed 2 μm / h, specifically 1.8 μm / h, 1.5 μm / h, 1.3 μm / h, 1 μm / h, or 0.5 μm / h. Preferably, it is 1 μm / h. In the above process, controlling the growth rate to 2 μm / h, based on the seed crystal's experienced particle size as the initial particle size, and the final desired particle size of the spherical basic copper chloride as the target particle size, the growth rate required per hour is calculated using the difference between the target particle size and the initial particle size, thus obtaining the growth rate.

[0049] In some embodiments, the stabilizer is ammonium bicarbonate, and the amount of stabilizer added is 1 / 1000 to 1 / 100 of the total mass of the seed dispersion, acidic copper-containing etching waste liquid, and ammonia. During the preparation process, the stabilizer and water are mixed to prepare a 30% (w / w) solution and added proportionally. The addition of the stabilizer stabilizes the crystal form of spherical basic copper chloride, ultimately yielding stable spherical basic copper chloride. In some embodiments, the amount of stabilizer added can be 1 / 1000, 1 / 800, 1 / 500, 1 / 300, or 1 / 100 of the total mass of the reactants (seed dispersion, acidic copper-containing etching waste liquid, and ammonia).

[0050] The specific method for separation in step S3 is as follows: the product after the reaction of the mixed reactants is transported to a hydrocyclone for separation, the separated solid material is collected, dried, and spherical basic copper chloride intermediate is obtained.

[0051] In some embodiments, a hydrocyclone is used for hydrocyclone separation at a rotation speed of 30–70 r / min. Solid and suspended materials are separated, and the suspended material is recovered and added back to the reactor as a mixed reactant, thereby improving the utilization rate of the mixed reactant and saving costs. Hydrocyclone separation technology can screen out basic copper chloride particles that meet the particle size and morphology requirements from the reaction products. Smaller particles of basic copper chloride are mixed in the suspended material; this suspended material is then added back to the mixed reactant to continue the reaction and collect more spherical basic copper chloride. In some embodiments, the rotation speed of the hydrocyclone can be 30 r / min, 40 r / min, 50 r / min, or 70 r / min.

[0052] In some embodiments, the temperature for drying the solid material is 50–130°C to fully dry the solid material, reduce its water content, improve the structural stability of the final product, spherical basic copper chloride, and prevent clumping due to the presence of moisture in the basic copper chloride during subsequent storage. In actual production, the solid material separated from the hydrocyclone is wet, and within the above temperature range, the solid material can be fully dried. The drying temperature can be 50°C, 60°C, 70°C, 80°C, 90°C, 100°C, 110°C, 120°C, or 130°C.

[0053] The spherical basic copper chloride prepared in this application has a smooth surface, a particle size of 50–100 μm, and a purity of over 99%. This spherical basic copper chloride can be used as a raw material for the production of downstream copper salt products, such as copper hydroxide and copper chloride, as a copper source for feed additives, and as a raw material for inorganic copper formulations in the pesticide field, such as copper oxychloride. Furthermore, the spherical morphology of the basic copper chloride prepared by this method gives it greater application and development value in materials science and other fields.

[0054] S4. Mix the intermediate prepared in step S3 with the solvent until homogeneous to obtain an intermediate dispersion.

[0055] Since spherical basic copper chloride is insoluble in water, mixing the intermediate and solvent evenly allows the intermediate to be uniformly dispersed in the solvent, which is beneficial for subsequent reactions.

[0056] In some implementations, the solvent is water or a base liquid, which is the liquid recovered from washing the sediment.

[0057] S5. Add ammonia to the intermediate dispersion and stir. The mass ratio of the intermediate to the ammonia is 1:1.05 to 1:1.15. After the reaction, separate the sediment, wash and dry it to obtain the hollow spherical copper hydroxide.

[0058] In the preparation of hollow spherical copper hydroxide, an intermediate dispersion containing spherical basic copper chloride and ammonia water are mixed in a certain proportion and reacted. The ammonia water reacts with the spherical basic copper chloride, and some of the copper and chlorine elements in the spherical basic copper chloride combine with the ammonia water to form a liquid-phase diamminecopper chloride [Cu(NH3)2Cl2] complex, which then enters the solution, thereby converting the spherical basic copper chloride into hollow spherical copper hydroxide. The preparation method of this application is simple and controllable, conducive to large-scale production, with a particle size of 5–200 μm, a purity of over 98%, good stability, and can be stored for up to 1.5 years without discoloration or clumping. Furthermore, the prepared hollow spherical copper hydroxide has a large specific surface area, making it widely applicable in dyeing, sterilization, or catalyst fields.

[0059] The main chemical reaction that occurs in this step is:

[0060] 2Cu2(OH)3Cl+2NH3·H2O=3Cu(OH)2+Cu(NH3)2Cl2+2H2O

[0061] Under the above reaction conditions, ammonia reacts with spherical basic copper chloride, and the ammonia reacts with some copper and chlorine, consuming 1 / 4 of the copper and all of the chlorine in the spherical basic copper chloride and forming a liquid-phase diamminecopper chloride [Cu(NH3)2Cl2] complex product, which flows into the solution. After the reaction, the spherical basic copper chloride is converted into copper hydroxide. In the above reaction, because the solution environment on the surface of the spherical basic copper chloride is uniform and it comes into contact with the solution first, the above reaction preferentially occurs on the surface of the spherical basic copper chloride. As the reaction time progresses and the reaction deepens, the solution gradually penetrates into the center of the spherical basic copper chloride and continues to react inside the sphere, while continuously releasing the diamminecopper chloride complex product into the solution. During the reaction, there are interconnected interfaces inside the spherical basic copper chloride crystal particles, and the reaction also gradually penetrates into the center of the spherical basic copper chloride along the interfaces. When the reaction proceeds to the center of the spherical basic copper chloride, the center is where the initially formed basic copper chloride is formed. It is relatively weak and the stress concentration in the center of the sphere is the most obvious. This causes the copper hydroxide formed in the center to become unstable and move radially towards the surface of the sphere, making the center of the sphere hollow, and finally forming a hollow spherical copper hydroxide.

[0062] The mass ratio of the intermediate to the ammonia is 1:1.05 to 1:1.15. Within this range, the ammonia and the intermediate can react fully. If this ratio is too small, the ammonia will be in excess, resulting in waste of raw materials and also preventing the excess ammonia from reacting with copper hydroxide to form a copper chloride complex. If this ratio is too large, the ammonia will be insufficient, and the reaction between the spherical basic copper chloride and the ammonia will be incomplete, resulting in a mixture of spherical basic copper chloride and hollow spherical copper hydroxide. In some embodiments, the mass ratio is 1:1.05, 1:1.1, or 1:1.05.

[0063] In some embodiments, the reaction temperature of the intermediate dispersion and ammonia is 40–60°C, which promotes the reaction rate. If the reaction temperature is below 40°C, the effect on promoting the reaction rate is not significant; if the reaction temperature is above 60°C, the copper hydroxide obtained may undergo a dehydration reaction to form copper oxide, resulting in an impure product with a black color. In some embodiments, the reaction temperature is 40°C, 45°C, 50°C, 55°C, or 60°C.

[0064] In some embodiments, the stirring speed for the reaction of the intermediate dispersion and ammonia is 50–100 r / min to ensure thorough mixing of the intermediate dispersion and ammonia, thereby promoting uniform reaction. In some embodiments, the stirring speed is 50 r / min, 60 r / min, 70 r / min, 80 r / min, 90 r / min, or 100 r / min.

[0065] In some embodiments, the mass ratio of the intermediate to the solvent is 1:1 to 2:1, so that the intermediate can be uniformly dispersed in the solvent. The mass ratio of the intermediate to the solvent is 1:1, 1.5:1, or 2:1.

[0066] In some embodiments, the mass fraction of ammonia is 15-30%, and the flow rate of ammonia added to the intermediate dispersion is 0.5-1.5 m / s. 3 / h. Controlling the flow rate of ammonia water can control the reaction between ammonia water and spherical basic copper chloride, preventing excessively fast flow rates and large amounts of ammonia water from contacting the intermediate, which would cause the reacted copper hydroxide to form a copper chloride complex. The mass fraction of ammonia water can be 15%, 20%, 25%, or 30%; the flow rate of ammonia water added is 0.5m. 3 / h, 1.0m 3 / h or 1.5m 3 / h. In some embodiments, the flow rate of ammonia water can be calculated according to the formula v=V / t, where v is the flow rate of ammonia water, V is the effective volume of the reaction vessel, and t is the reaction time of the intermediate dispersion and ammonia water.

[0067] In some embodiments, the reaction time between the intermediate dispersion and ammonia is 0.5 h to 2 h to ensure sufficient reaction to obtain copper hydroxide. The reaction time can be 0.5 h, 1 h, 1.5 h, or 2 h.

[0068] In some embodiments, the temperature for drying the deposit is 50–105°C. Within this range, while ensuring a certain drying efficiency, excessively high temperatures are avoided to prevent the copper hydroxide from dehydrating and converting into copper oxide, resulting in an impure product with a black color. The drying temperature can be 50°C, 60°C, 80°C, 100°C, or 105°C.

[0069] This application also provides a hollow spherical copper hydroxide, prepared by the aforementioned method. The hollow spherical copper hydroxide prepared by this application is blue in color, has a particle size of 5–200 μm, a purity of over 98%, and can be stably stored at room temperature for more than 1.5 years without discoloration or clumping, exhibiting good stability.

[0070] In some embodiments, the hollow spherical copper hydroxide includes a hollow portion, which occupies 1 / 4.5 to 1 / 3.5 of the total volume of the hollow spherical copper hydroxide. Compared with copper hydroxide of other morphologies, the formation of the hollow portion increases the specific surface area of ​​the spherical copper hydroxide, and to a certain extent also improves the activity and bactericidal properties of copper hydroxide as a bactericide.

[0071] The hollow spherical copper hydroxide prepared in this application can be used as a raw material for the production of downstream copper salt products, such as copper oxide, copper carbonate, copper chloride, and copper sulfate. It can also be used as a raw material for copper hydroxide formulations in pesticides and fungicides. Furthermore, due to the unique hollow spherical morphology of the copper hydroxide prepared by this method, it has a larger specific surface area than copper hydroxide prepared by other methods. This characteristic gives hollow spherical copper hydroxide greater advantages in applications such as materials and catalysts.

[0072] The present invention will be explained below with reference to embodiments. Those skilled in the art will understand that the following examples are for illustrative purposes only and should not be construed as limiting the invention. Unless otherwise stated, reagents, software, and instruments involved in the following embodiments that are not specifically described are all conventional commercially available products or open-source materials.

[0073] The composition of the acidic copper-containing etching waste liquid after impurity removal in this application is shown in Table 1. The following examples and comparative examples in this application all use acidic copper-containing etching waste liquid after impurity removal, which refers to acidic copper-containing etching waste liquid obtained after removing impurities such as dioxins, arsenic, lead, cadmium, nickel and insoluble solids.

[0074] Table 1. Composition content of acidic copper-containing etching waste liquid after impurity removal

[0075] project Cu, g / L H, mol / L Ni, mg / L Cd, mg / L As, mg / L Pb, mg / L Dioxins, ng / kg content 120 1.5 0.5 0.05 0.1 0.04 21

[0076] Example 1

[0077] In a 5 cubic meter reactor, 1 cubic meter of water and 0.5 kg of hydrochloric acid-catalyzed basic copper chloride seed crystals were added and stirred thoroughly to obtain a seed crystal dispersion.

[0078] With 2m 3 The flow rate will be 2m / h 3 The above-mentioned acidic copper-containing etching waste liquid was treated at a concentration of 0.5 m... 3 The flow rate will be 0.5m / h. 3 Ammonia solution with a mass fraction of 20% and ammonium bicarbonate stabilizer of 5.8 kg at a rate of 5.8 kg / h were simultaneously added to the reactor and mixed with the seed crystal dispersion to obtain a mixed reactant with a pH of 4.8.

[0079] The mixed reactants were heated and continuously stirred at a speed of 180 r / min at 45 °C for 5 h. The resulting product was then transferred to a hydrocyclone for hydrocyclone separation at 50 r / min, separating solids and suspended material. The suspended material was then reintroduced into the reactor for further reaction. The collected solids were dried at 70 °C for 5 h to obtain spherical basic copper chloride intermediates.

[0080] 150 kg of spherical basic copper chloride and water were added to a reaction vessel at a mass ratio of 1:1 and stirred until homogeneous to obtain an intermediate dispersion. Ammonia solution with a mass fraction of 20% was added at a mass ratio of 1:1.05 to the spherical basic copper chloride and ammonia solution, and the reaction was continuously stirred at a flow rate of 1 m / s. 3 The reaction was carried out at a rate of 60 r / min at a temperature of 40 °C for 50 min, followed by filtration to obtain a sediment. The sediment was washed repeatedly with water and dried at 100 °C to obtain 96 kg of hollow spherical copper hydroxide with an average particle size of 50 μm.

[0081] Comparative Example 1

[0082] The difference between Comparative Example 1 and Example 1 is that the seed crystal used in Comparative Example 1 is the product of basic copper chloride catalytic weathering with acetic acid (the specific preparation steps are recorded in Example 1 of Patent No. 200810218161.2), and a basic copper chloride intermediate was prepared.

[0083] Comparative Example 2

[0084] The difference between Comparative Example 2 and Example 1 is that no seed crystals or stabilizers were added in the reactor, and a basic copper chloride intermediate was prepared. See also... Figure 1 and Figure 2In this application, X-ray diffraction tests were performed on the intermediate and hollow spherical copper hydroxide prepared in Example 1. The analytical instrument used was an X-ray diffractometer (SHIMADZU XRD~6000, D / max 2500v / pc, Cu Kαradiation), with continuous scanning mode, scanning range of 10~75deg and 5~90deg, scanning speed of 5deg / min, presentation time of 1.00sec, voltage of 40kV, and current of 30A.

[0085] from Figure 1 As can be seen from the XRD pattern, the intermediate obtained in Example 1 has a good match with the data on card 78-0372 (Cu2Cl(OH)3, Atacamite). This product belongs to the orthorhombic Pnma(62) crystal system with a cell parameter of 6.03×6.865×9.12 (90.0×90.0×90.0). This indicates that the intermediate prepared in Example 1 is a basic copper chloride product.

[0086] from Figure 2 As can be seen from the figure, the XRD pattern of the hollow spherical copper hydroxide prepared in Example 1 has a good match with card 80-0656 (Cu(OH)2, Copper Hydroxide). This product belongs to the orthorhombic crystal system Cmc21(36), with cell parameters of 2.9471×10.593×5.2564 (90.0×90.0×90.0). This proves that copper hydroxide was successfully prepared in Example 1.

[0087] This application also includes microscopic tests on the intermediate prepared in Example 1, the hollow spherical copper hydroxide, and the cross-section of the hollow spherical copper hydroxide at 200x magnification. The analytical instrument was a metallurgical microscope (analytical instrument: Leica DM2500M, Germany).

[0088] from Figure 3 As can be seen, the intermediate crystals are dark green spherical with smooth surfaces, uniform particle size, and uniform dispersion. This indicates that spherical basic copper chloride was prepared in Example 1.

[0089] In addition, this application also conducted microscopic tests at magnification on the basic copper chloride products prepared in Comparative Example 1 and Comparative Example 2. From Figure 4 As can be seen, the surface of the basic copper chloride product has many sharp edges and corners, is irregular, and does not form spherical particles. This indicates that in Example 1, when hydrochloric acid is used as a seed crystal to catalyze basic copper chloride, the chloride ions in the hydrochloric acid act on the basic copper chloride during the preparation process, which is beneficial for the subsequent formation of spherical basic copper chloride.

[0090] from Figure 5Observation revealed that even without the addition of seed crystals and stabilizers, basic copper chloride exhibited numerous sharp edges and corners on its surface, with uneven particle size and irregular shapes. This indicates that the combination of seed crystals and stabilizers facilitates the formation of spherical basic copper chloride.

[0091] from Figure 6 As can be seen, the hollow spherical copper hydroxide crystals are blue and spherical, with uniform and evenly dispersed crystal particles. From... Figure 7 It can be seen that the cross-section of a single particle is hollow sphere-shaped, with a particle diameter of approximately 61.5 μm, a shell thickness of approximately 31 μm, and an internal hollow sphere diameter of approximately 30.6 μm. Combined with... Figure 6 and Figure 7 This indicates that hollow spherical copper hydroxide was prepared in Example 1.

[0092] The above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions to the technical solutions of the present invention should not depart from the spirit and scope of the technical solutions of the present invention.

Claims

1. A method for producing hollow spherical copper hydroxide, characterized by, The preparation method comprises: mixing seeds and water to obtain a seed dispersion, the seeds comprising copper hydrochloride catalytic basic chloride; adding impurity-removed acidic copper-containing etching waste liquid, ammonia water and a stabilizer to the seed dispersion to obtain a mixed reaction product with a pH value of 4-5.5; heating the mixed reaction product at a temperature of 40-80°C and stirring the mixed reaction product at a stirring speed of 100-200 r / min, and then separating solid substances, drying to obtain an intermediate, the intermediate comprising spherical basic copper chloride; mixing the intermediate and a solvent to obtain an intermediate dispersion; adding ammonia water to the intermediate dispersion and stirring, the mass ratio of the intermediate to the ammonia water being 1:1.05-1:1.15, and then separating precipitates, washing, drying to obtain the hollow spherical copper hydroxide.

2. The method for preparing hollow spherical copper hydroxide as described in claim 1, characterized in that, The reaction temperature of the intermediate dispersion and the ammonia water is 40-60°C.

3. The method for preparing hollow spherical copper hydroxide as described in claim 1, characterized in that, The stirring speed of the intermediate dispersion and the ammonia water is 50-100 r / min.

4. The method for preparing hollow spherical copper hydroxide as described in claim 1, characterized in that, The mass ratio of the intermediate to the solvent is 1:1-2:

1.

5. The method for preparing hollow spherical copper hydroxide as described in claim 1, characterized in that, The mass fraction of the ammonia water is 15-30%.

6. The method for preparing hollow spherical copper hydroxide as described in claim 1, characterized in that, The reaction time of the intermediate dispersion and the ammonia water is 0.5 h-2 h.

7. The method for preparing hollow spherical copper hydroxide as described in claim 1, characterized in that, The solvent is water or a bottom liquid, the bottom liquid being a liquid recovered by washing the precipitates.

8. The method for preparing hollow spherical copper hydroxide as described in claim 1, characterized in that, The drying temperature of the precipitates is 50-105°C.

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