Active copper oxide preparation method capable of recycling ammonia and carbon

Abstract

The invention provides a method for preparing active copper oxide by recycling ammonia and carbon. The method comprises the following steps: step 1, preparing a copper dissolving reagent from ammonia water and carbon dioxide; 2, the copper raw material and a copper dissolving reagent are mixed, oxygen or air is introduced, heating and pressurizing are carried out for an ammonia leaching complexing reaction, and a copper ammonia complex is obtained; step 3, after the copper ammonia complex is filtered, rectifying to remove ammonia and carbon, producing ammonia gas and carbon dioxide at the tower top, and producing basic cupric carbonate slurry at the tower kettle; 4, centrifuging and drying the basic cupric carbonate slurry to obtain a basic cupric carbonate solid; and 5, calcining the basic cupric carbonate solid at high temperature to produce active copper oxide. According to the active copper oxide preparation method capable of recycling ammonia and carbon, the active copper oxide with high purity and uniform particle size can be directly prepared.

Description

Technical Field

[0001] The invention relates to the technical field of active copper oxide production, and in particular to a method for preparing active copper oxide by recycling ammonia and carbon. Background Art

[0002] In the prior art, the production of active copper oxide has the following problems:

[0003] (1) It is impossible to directly produce active copper oxide. Copper oxide is first produced and then crushed and ground to prepare active copper oxide.

[0004] (2) The purity of active copper oxide is low and the impurity content is high;

[0005] (3) The deammoniation process is carried out by intermittent heating in an ammonia evaporator, which results in a long deammoniation time and a low ammonia removal rate. For the treatment of 1 ton of copper raw material, the heating deammoniation time for one kettle of copper-ammonia complex is more than 10 hours.

[0006] Therefore, it is of great significance to provide a method for preparing activated copper oxide that can directly produce high-purity, uniform-sized activated copper oxide and has a short reaction time and ammonia-carbon recycling. Summary of the invention

[0007] Based on the above objectives, the present invention provides a method for preparing activated copper oxide by recycling ammonia and carbon to solve or partially solve the above technical problems:

[0008] A method for preparing active copper oxide by recycling ammonia and carbon, comprising:

[0009] Step 1: Prepare a copper dissolving reagent with ammonia water and carbon dioxide;

[0010] Step 2: The copper raw material is mixed with a copper dissolving reagent, oxygen or air is introduced, and the mixture is heated and pressurized to perform an ammonia leaching complex reaction to obtain a copper-ammine complex;

[0011] Step 3: After the copper-ammine complex is filtered, distillation is performed to remove ammonia carbon, and ammonia and carbon dioxide are produced at the top of the tower, and basic copper carbonate slurry is produced at the bottom of the tower;

[0012] Step 4: The basic copper carbonate slurry is centrifuged and dried to obtain basic copper carbonate solid;

[0013] Step 5: The basic copper carbonate solid is calcined at high temperature to produce active copper oxide.

[0014] Furthermore, step 1 specifically includes: introducing ammonia water and carbon dioxide into a carbonization tower to carry out a carbonization reaction to prepare a copper-dissolving reagent.

[0015] Furthermore, in step 2: the ammonia leaching complexation reaction is carried out in a closed reactor.

[0016] Furthermore, in step 3: the distillation adopts negative pressure distillation, and the operating pressure of the distillation tower is controlled to be 35-80Kpa, and the operating temperature is 75-95°C.

[0017] Furthermore, the ammonia nitrogen content in the bottom liquid of the distillation tower is controlled to be ≤20ppm.

[0018] Furthermore, the distillation tower includes an upper head, a cylinder and a lower cone section welded in sequence from top to bottom, and a vertical sieve plate is arranged in the cylinder.

[0019] Furthermore, the distillation is a continuous distillation.

[0020] Furthermore, in step 3:

[0021] The ammonia and carbon dioxide produced at the top of the tower are sent to the absorption tower through a jet vacuum pump and absorbed by water to form carbon-containing ammonia water;

[0022] The carbon-containing ammonia water is sent to step 1 to prepare the copper-dissolving reagent.

[0023] Further, in step 4, the supernatant after centrifugation of the basic copper carbonate slurry is sent to step 2 to recover ammonia nitrogen and basic copper carbonate in the supernatant.

[0024] Furthermore, in step 5, the carbon dioxide tail gas generated by the high-temperature calcination of basic copper carbonate solid is sent to the tail gas treatment system for tail gas treatment.

[0025] From the above description, it can be seen that the method for preparing active copper oxide by ammonia-carbon recycling provided by the present invention has the following beneficial effects:

[0026] Active copper oxide has high purity and uniform grains:

[0027] The ammonia and ammonium bicarbonate solution type copper dissolving reagent is directly prepared online with ammonia water and carbon dioxide, and the ammonium bicarbonate crystal containing additives is not used for dissolution and configuration. The copper dissolving reagent has high purity and copper oxide has high purity;

[0028] Deammoniation is carried out by distillation, and the purity of basic copper carbonate is high, and thus the purity of copper oxide is high: (1) The distillation operating temperature is 75-95°C, and the operating temperature is low to avoid high-temperature decomposition of basic copper carbonate and oxidation of copper; (2) The ammonia nitrogen in the bottom liquid-basic copper carbonate slurry is ≤20ppm, and the ammonia nitrogen removal rate is high, which avoids the subsequent high-temperature calcination of basic copper carbonate to produce copper oxide, and the ammonia decomposition to generate hydrogen, which reduces copper oxide to copper element. (3) The distillation tower and its components are connected by welding, which has good sealing performance, preventing oxygen from leaking into the copper element for oxidation and forming scars in the copper oxide tower. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 This is a schematic flow chart of a method for preparing activated copper oxide by recycling ammonia and carbon according to an embodiment of the present invention. DETAILED DESCRIPTION

[0031] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments and with reference to the accompanying drawings.

[0032] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Including" or "comprising" and similar words mean that the elements or objects appearing before the word cover the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connected" or "connected" and similar words are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0033] One or more embodiments of the present invention provide a method for preparing active copper oxide by recycling ammonia and carbon, comprising:

[0034] Step 1: Prepare a copper dissolving reagent with ammonia water and carbon dioxide. Specifically, the process includes: diluting ammonia water to a desired concentration, gasifying liquid carbon dioxide, mixing and absorbing the gasified carbon dioxide with ammonia water, and performing a carbonization reaction to generate a copper dissolving reagent online - a mixed solution containing ammonia and ammonium bicarbonate.

[0035] In the prior art, the copper dissolving reagents are: ammonia water, ammonium bicarbonate; during the ammonia leaching complex reaction: ammonia water, ammonium bicarbonate and copper raw materials are mixed, heated and stirred to generate copper ammonia complex. There are mainly the following problems:

[0036] (1) Ammonium bicarbonate is a white crystalline compound. During its preparation, additives need to be added to ensure crystallization and reduce the water content in the product. The copper-ammine complex generated by ammonia leaching will also be mixed with additives, thereby affecting the purity of the final product, copper oxide.

[0037] (2) The conventional ammonia concentration is generally 25%w. The higher the ammonia concentration, the greater the volatilization loss. The ammonia content in the copper dissolving reagent is generally controlled at 5%-20%w. During the ammonia leaching complex reaction, external water is required for dilution, which increases the difficulty of controlling the ammonia leaching complex reaction and increases the reaction time.

[0038] In the present application, ammonia and ammonium bicarbonate solution-type copper-dissolving reagent is directly prepared online with ammonia water and carbon dioxide, and ammonium bicarbonate crystals containing additives are not used for dissolution and configuration. The copper-dissolving reagent has high purity, thereby ensuring the purity of the final product copper oxide.

[0039] Step 1 specifically includes: passing ammonia water and carbon dioxide into a carbonizing tower, performing a carbonization reaction, and preparing a copper-dissolving reagent. A filler is arranged in the carbonizing tower, and the carbonized liquid-copper-dissolving reagent in the tower bottom is sent to the top of the carbonizing tower for reflux and reabsorption after cooling. The carbon dioxide absorption effect is good, and the copper-dissolving reagent preparation efficiency is high. In addition, by controlling the feed amount of ammonia water and carbon dioxide, the carbonization temperature, pressure, etc., the composition requirements of the copper-dissolving reagent are guaranteed.

[0040] Step 2: The copper raw material is mixed with a copper dissolving reagent, oxygen or air is introduced, and the mixture is heated and pressurized to perform an ammonia leaching complexation reaction to obtain a copper-ammine complex.

[0041] Furthermore, in step 2: the ammonia leaching complexation reaction is carried out in a closed reactor.

[0042] The copper raw material and the copper dissolving reagent are added to a closed reactor, oxygen or air is introduced, and after heating for a certain period of time under pressurized conditions, soluble copper-ammonia complex ions are formed and enter the solution, completing the dissolution and leaching of copper to form copper-ammonia complexes. Pressurized copper leaching can increase the ammonia leaching rate and reduce the ammonia leaching reaction time. The closed reactor can reduce the escape of ammonia.

[0043] Copper raw materials can be copper ore, waste copper catalyst, copper foil, etc. For copper raw materials with many impurities and low copper content such as copper ore and waste copper catalyst, they can be pulverized, impurity-removed and then ammonia-leached; for copper raw materials with high purity such as copper foil, ammonia-leaching can be carried out directly.

[0044] In order to ensure the ammonia leaching complex reaction, the amount of copper dissolving reagent added is excessive, so that the copper-ammine complex solution contains excessive ammonia and ammonium bicarbonate.

[0045] Step 3: After the copper-ammine complex is filtered, distillation is performed to remove ammonia carbon, and ammonia and carbon dioxide are produced at the top of the tower, and basic copper carbonate slurry is produced at the bottom of the tower.

[0046] There are two main purposes of distillation: one is to remove excess ammonia and ammonium bicarbonate by distillation, and the other is to decompose the copper ammonia complex into basic copper carbonate, ammonia and carbon dioxide under heat. The chemical equation is:

[0047] 2[Cu(NH3)4C03]+H20--Cu2(0H)2C03↓+C02↑+8NH3↑.

[0048] In the prior art, the decomposition and deammonification method of copper ammonia complex is that the ammonia still kettle intermittently decomposes a certain amount of copper ammonia complex. Specifically: a certain amount of copper ammonia complex is added to the ammonia still kettle at one time, steam / heat transfer oil is passed into the jacket of the reactor to heat and decompose the ammonia, and a fan is set on the top of the reactor to extract ammonia and carbon dioxide. This method has the following problems:

[0049] (1) Decomposition and deamination in an ammonia still is a single-stage deamination process, similar to flash evaporation, and takes a long time to deaminize. For example, a plant processes 1 ton of copper raw material, and the corresponding kettle of copper-ammonia complex takes more than 10 hours to heat and deaminize, which results in low processing efficiency. The long heating time means that the material cannot be delivered to the subsequent processing steps in time, and the possibility of the material coming into contact with oxygen and undergoing qualitative changes increases. For example, oxygen leaks in, copper is oxidized, copper oxide is generated, and black scars appear in the ammonia still.

[0050] (2) The deammoniation effect is poor. The ammonia nitrogen content in the ammonia still liquid-basic copper carbonate solution is generally as high as 3000-6000ppm. Therefore: 1. The ammonia nitrogen impurity content of basic copper carbonate is large and the purity is low; 2. In the subsequent high-temperature calcination of basic copper carbonate to produce copper oxide, ammonia decomposes into hydrogen, and hydrogen reduces copper oxide to copper elemental mixed in copper oxide, reducing the purity and yield of copper oxide.

[0051] (3) The ammonia still is a kettle-type container, which is operated intermittently. The processing capacity of a batch of materials is large, and the jacket is used for indirect heating, so the heating in the kettle is uneven. In places where the heating is insufficient, the copper ammonia complex is difficult to decompose; in places where the heating is excessive, basic copper carbonate decomposes to produce copper oxide. In the end, the products in the kettle are diversified, including copper ammonia complex, basic copper carbonate, copper oxide and other substances.

[0052] The above reasons make the subsequent drying of basic copper carbonate slurry into green blocks with black impurities. Basic copper carbonate itself, as a chemical, can be used to make flares, fireworks, paint pigments, pesticides and antidotes, etc., while the application of impurities in basic copper carbonate will be greatly limited.

[0053] In addition, pure basic copper carbonate is in the form of loose powder. However, when the basic copper carbonate slurry contains multiple impurities such as copper-ammonia complex, basic copper carbonate, copper oxide, ammonia, etc., it is in the form of a cohesive block after drying. The copper oxide produced by subsequent high-temperature calcination of basic copper carbonate solid is also in the form of a cohesive block, which needs to be crushed and ground to reach the standard of active copper oxide.

[0054] Furthermore, in step 3: distillation is carried out in a distillation tower, and the distillation adopts negative pressure distillation, and the operating pressure of the distillation tower is controlled to be 35-80Kpa, and the operating temperature is 75-95°C.

[0055] The present application adopts the method of distillation, which is carried out in a distillation tower. Steam is directly introduced into the bottom of the tower, or it is indirectly heated through a reboiler, so that the tower is evenly heated. The distillation adopts negative pressure distillation, and the operating pressure of the distillation tower is controlled at 35-80Kpa and the operating temperature is 75-95°C. At this temperature, the decomposition rate of the copper ammonia complex is high, and the temperature at which basic copper carbonate decomposes and the copper element is oxidized is not reached. Uniform heating + low-temperature decomposition makes the bottom product of the tower uniform: basic copper carbonate.

[0056] Furthermore, the ammonia nitrogen content in the bottom liquid is controlled to be ≤20ppm. The low ammonia nitrogen content in the bottom liquid-basic copper carbonate reduces the reduction effect of hydrogen decomposed from ammonia on copper oxide during the subsequent calcination of basic copper carbonate to form copper oxide. The low ammonia nitrogen content ensures the purity of basic copper carbonate and the purity of subsequent copper oxide.

[0057] Furthermore, the distillation tower includes an upper head, a cylinder and a lower cone section welded in sequence from top to bottom, and a plurality of vertical sieve plates are arranged in the cylinder. The distillation tower is sealed to prevent oxygen from entering and reacting with the copper element to oxidize it, thereby ensuring the purity of the bottom liquid.

[0058] The bottom liquid of the distillation tower is basic copper carbonate slurry, and the bottom of the distillation tower is set into a large-angle cone to facilitate the discharge of the liquid. The tower plate is a vertical sieve plate with good anti-blocking performance.

[0059] Furthermore, the distillation is continuous distillation. The residence time of the material in the tower is short, so as to avoid the material being heated for a long time or contacting with air, etc., which may cause the material to decompose or oxidize to produce impurity products.

[0060] Uniform heating + low temperature decomposition + low ammonia nitrogen content + sealing to prevent oxygen leakage ensures the purity of basic copper carbonate slurry and further ensures the purity of copper oxide. Basic copper carbonate slurry has high purity, not only its own particle size is uniform, but also the particle size of the final product copper oxide is also uniform and fine, reaching the standard of active copper oxide, without the need for subsequent special crushing and grinding.

[0061] The present application uses a jet vacuum pump to control the pressure of the ammonia distillation tower to 35-80Kpa. Furthermore, the ammonia, carbon dioxide and water vapor produced at the top of the tower are sent to the absorption tower through the jet vacuum pump and absorbed by water to form carbon-containing ammonia water.

[0062] When the tower top gas is condensed through the tower top condenser, ammonia, carbon dioxide and water vapor will be condensed to regenerate ammonium bicarbonate. Ammonium bicarbonate is easy to crystallize when it is cooled, but the flow channel of the tower top condenser is narrow and easily blocked. Therefore, ammonia and carbon dioxide directly enter the absorption tower and are absorbed by water to form ammonia-ammonium bicarbonate mixed liquid. The tower flow channel is large, not easy to be blocked, and easy to clean and control.

[0063] The carbon-containing ammonia water is sent to step 1 to prepare a copper-dissolving reagent to achieve the recycling and resource utilization of carbon and ammonia.

[0064] Furthermore, in step 4, the supernatant after centrifugation of the basic copper carbonate slurry is the basic copper carbonate mother liquor, which contains not only basic copper carbonate but also part of ammonia carbon, and is sent to step 2 for recycling and participation in the ammonia leaching complexation reaction.

[0065] Furthermore, in step 5, the high-temperature calcination reaction of basic copper carbonate is: Cu2(OH)2CO3=2CuO+CO2↑+H2O, generating tail gas containing carbon dioxide, which is sent to the tail gas treatment system for tail gas treatment.

[0066] It can be seen from the above that the method for preparing activated copper oxide for ammonia-carbon recycling of the present invention can realize systematic ammonia-carbon recycling, and the prepared copper oxide has a uniform and fine particle size, which can meet the standard of activated copper oxide.

[0067] It should be understood by those skilled in the art that the discussion of any of the above embodiments is merely illustrative and is not intended to imply that the scope of the present invention, including the claims, is limited to these examples; within the spirit of the present invention, the technical features in the above embodiments or in different embodiments may be combined, the steps may be implemented in any order, and there are many other variations of the above aspects of the present invention, which are not provided in detail for the sake of simplicity.

[0068] The embodiments of the present invention are intended to cover all such substitutions, modifications and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing activated copper oxide by recycling ammonia and carbon, characterized in that: include: Step 1: Prepare a copper dissolving reagent with ammonia water and carbon dioxide; Step 2: The copper raw material is mixed with a copper dissolving reagent, oxygen or air is introduced, and the mixture is heated and pressurized to perform an ammonia leaching complex reaction to obtain a copper-ammine complex; Step 3: After the copper-ammine complex is filtered, distillation is performed to remove ammonia carbon, and ammonia and carbon dioxide are produced at the top of the tower, and basic copper carbonate slurry is produced at the bottom of the tower; Step 4: The basic copper carbonate slurry is centrifuged and dried to obtain basic copper carbonate solid; Step 5: The basic copper carbonate solid is calcined at high temperature to produce active copper oxide.

2. The method for preparing activated copper oxide by ammonia-carbon recycling according to claim 1, characterized in that: Step 1 specifically includes: introducing ammonia water and carbon dioxide into a carbonization tower to carry out a carbonization reaction to prepare a copper-dissolving reagent.

3. The method for preparing activated copper oxide by ammonia-carbon recycling according to claim 1, characterized in that: In step 2: the ammonia leaching complexation reaction is carried out in a closed reactor.

4. The method for preparing activated copper oxide by ammonia-carbon recycling according to claim 1, characterized in that: In step 3: the distillation adopts negative pressure distillation, and the operating pressure of the distillation tower is controlled at 35-80Kpa and the operating temperature is 75-95°C.

5. The method for preparing activated copper oxide by ammonia-carbon recycling according to claim 4, characterized in that: Control the ammonia nitrogen content in the distillation tower bottom liquid to ≤20ppm.

6. The method for preparing activated copper oxide by ammonia-carbon recycling according to claim 5, characterized in that: The distillation tower comprises an upper head, a cylinder and a lower cone section which are welded in sequence from top to bottom, and a vertical sieve plate is arranged in the cylinder.

7. The method for preparing activated copper oxide by ammonia-carbon recycling according to claim 1, characterized in that: The distillation is continuous distillation.

8. The method for preparing activated copper oxide by ammonia-carbon recycling according to claim 1, characterized in that: In step 3: The ammonia and carbon dioxide produced at the top of the tower are sent to the absorption tower through a jet vacuum pump and absorbed by water to form carbon-containing ammonia water; The carbon-containing ammonia water is sent to step 1 to prepare the copper-dissolving reagent.

9. The method for preparing activated copper oxide by ammonia-carbon recycling according to claim 1, characterized in that: In step 4, the supernatant after centrifugation of the basic copper carbonate slurry is sent to step 2 to recover ammonia nitrogen and basic copper carbonate in the supernatant.

10. The method for preparing activated copper oxide by ammonia-carbon recycling according to claim 1, characterized in that: In step 5, the carbon dioxide tail gas generated by high-temperature calcination of basic copper carbonate solid is sent to the tail gas treatment system for tail gas treatment.

Images