Preparation method of basic copper salt

Abstract

The present invention discloses a preparation method of basic copper salt, which comprises the following steps: S1: Prepare an ammonium bicarbonate solution; S2: Add solid basic copper chloride to the ammonium bicarbonate solution, or pour the ammonium bicarbonate solution into the solid basic copper chloride to obtain a mixed solution, wherein the solid-liquid ratio is 1:5-20; S3: Heat up and keep warm the mixed solution obtained in S2 to obtain a suspension of basic copper carbonate precursor; S4: Continue to heat up and keep warm the suspension of basic copper carbonate precursor obtained in S3 to obtain a basic copper carbonate feed liquid; S5: Carry out solid-liquid separation, washing and drying on the basic copper carbonate feed liquid obtained in S4 in sequence to obtain blue basic copper carbonate powder. The present invention provides a preparation method of basic copper salt, which solves the problems of poor repeatability in the extraction of natural blue basic copper carbonate, cumbersome extraction process, unstable impurities, etc.

Description

Technical Field

[0001] The present invention relates to the technical field of inorganic salt production processes, and particularly to a method for preparing basic copper salts. Background Art

[0002] Basic copper carbonate is a basic copper salt, which exhibits different crystallizations according to different ratios of xCuCO3·yCu(OH)2·zH2O. CuCO3·Cu(OH)2 is malachite green, and 2CuCO3·Cu(OH)2 is peacock blue. Among them, CuCO3·Cu(OH)2 is used in industries such as catalysts, fireworks, pesticides, pigments, feeds, fungicides, electroplating, anti-corrosion, etc. and for manufacturing copper compounds, while 2CuCO3·Cu(OH)2 is mainly applied in aspects such as copper smelting raw materials, pigments, fungicides, etc.

[0003] Azurite and malachite are two symbiotic ores, and they can be transformed into each other under certain conditions. Azurite loses carbon dioxide and turns into malachite. Conversely, when malachite is in an environment with sufficient carbon dioxide, malachite may also turn into azurite. Malachite green basic copper carbonate is the most common in chemical synthesis products. The commonly used synthesis methods include reacting soluble copper salts with carbonates to prepare, forming a copper ammonia complex from copper salts and ammonium carbonate, and then obtaining it by distilling ammonia from the copper ammonia complex. Azurite is called azurite in pigments, and most of those sold on the market are extracted from natural azurite. The extraction process is as follows: The selected natural azurite is crushed and sieved, then ultrasonic cleaning is used to remove surface dirt and other impurities, and after natural drying, it is finely ground. The ground product is then dispersed, settled, and classified. The classified product is sorted to remove other impurity minerals, and then the surface is treated with dilute acid, and after sufficient washing and natural drying, azurite pigment is obtained. Among them, the classification process is the most important and cumbersome, and according to different classifications, the color of azurite varies.

[0004] There are relatively few patents related to chemical synthesis. For example, CN107311219B only discloses a method for purifying azurite pigment, using natural extracted azurite pigment, and purifying the natural azurite pigment by dispersing and reacting with externally added copper ions and carbonate radicals. CN112142089A discloses a method for synthesizing azurite pigment, in which soluble copper salts react with carbonates to generate a malachite reaction solution, the malachite reaction solution is aged in a closed and low-temperature manner with dry ice to obtain a suspension, and the suspension is ultrasonically dispersed, settled, solid-liquid separated, washed with water, dried, etc. to obtain azurite mineral pigment.

[0005] At present, there are very few chemical synthesis processes related to 2CuCO3·Cu(OH)2. Due to the characteristics of natural azurite, 2CuCO3·Cu(OH)2 is scarce, and there are also problems such as poor repeatability, unstable impurities, and cumbersome classification in the natural extraction of azurite. Therefore, it is particularly important to develop the chemical synthesis technology of 2CuCO3·Cu(OH)2. Summary of the Invention

[0006] The purpose of the present invention is to provide a preparation method of basic copper salt, which solves the problems of poor repeatability, cumbersome extraction process, and unstable impurities in the extraction of natural blue basic copper carbonate.

[0007] To achieve the above purpose, the following technical solutions are adopted:

[0008] A preparation method of basic copper salt includes the following steps:

[0009] S1: Prepare an ammonium bicarbonate solution;

[0010] S2: Add solid basic copper chloride to the ammonium bicarbonate solution, or pour the ammonium bicarbonate solution into the solid basic copper chloride to obtain a mixed solution, wherein the solid-liquid ratio is 1:5 - 20;

[0011] S3: Heat up and keep warm the mixed solution obtained in S2 to obtain a suspension of basic copper carbonate precursor;

[0012] S4: Continue to heat up and keep warm the suspension of basic copper carbonate precursor obtained in S3 to obtain a basic copper carbonate liquid material;

[0013] S5: Perform solid-liquid separation, washing, and drying on the basic copper carbonate liquid material obtained in S4 in sequence to obtain blue basic copper carbonate powder.

[0014] Further, in S1, first pour a predetermined volume of water into the reaction kettle, and then add solid ammonium bicarbonate and stir to obtain an ammonium bicarbonate solution, wherein the pH value of the ammonium bicarbonate solution is 7 - 10.

[0015] Further, the solid-liquid ratio is 1:8.

[0016] Further, in S3, first in the reaction kettle, heat up the suspension of basic copper carbonate precursor to between 30 - 45 °C, and then keep warm for 1 - 5 h.

[0017] Further, heat up the suspension of basic copper carbonate precursor to 40 °C.

[0018] Further, in S4, first in the reaction kettle, continue to heat up the suspension of basic copper carbonate precursor to between 40 - 90 °C, and then keep warm for 1 - 5 h.

[0019] Further, heat the suspension of the copper basic carbonate precursor to 80°C; control the pressure in the reaction kettle between 0 and 0.4 MPa.

[0020] Further, in S5, pump the copper basic carbonate feed liquid into a separator for solid-liquid separation.

[0021] Further, in S5, wash the solid obtained by solid-liquid separation with water slurries 1 to 5 times.

[0022] Further, in S5, dry the washed solid at a temperature between 60 and 120°C for 2 to 6 hours.

[0023] Adopting the above scheme, the beneficial effects of the present invention are as follows:

[0024] By using this method, 2CuCO3·Cu(OH)2 can be stably synthesized, solving the problems of poor repeatability in the extraction of natural blue copper basic carbonate, cumbersome extraction process, unstable impurities, etc. At the same time, this method is simple to operate and has good operating conditions, and can prepare a stable blue copper basic carbonate product by a one-step method. Among them, the conversion rate of Cu is between 70% and 85%. In addition, the obtained blue copper basic carbonate has a lower impurity content and a stable composition compared with the naturally extracted copper basic carbonate. Description of the Drawings

[0025] Figure 1 is a flow block diagram of the present invention;

[0026] Figure 2 is a physical diagram obtained in Example 1 of the present invention;

[0027] Figure 3 is a physical diagram obtained in Example 2 of the present invention;

[0028] Figure 4 is an XRD diagram of the physical object obtained in Example 1 of the present invention. Detailed Embodiments

[0029] The present invention will be described in detail below with reference to the drawings and specific embodiments.

[0030] Refer to Figures 1 to 4 As shown, the present invention provides a method for preparing a basic copper salt, including the following steps:

[0031] S1: Prepare an ammonium bicarbonate solution.

[0032] In this step, first pour a part of water (the volume of water can be preset according to requirements) into the reaction kettle, then add ammonium bicarbonate solid, and start the stirring device to stir. The ammonium bicarbonate solid begins to dissolve, and an ammonium bicarbonate solution at room temperature can be configured. Among them, the pH value of the ammonium bicarbonate solution is 7 to 10.

[0033] S2: Add copper hydroxychloride solid to the ammonium bicarbonate solution, or pour the ammonium bicarbonate solution into the copper hydroxychloride solid to obtain a mixed solution, where the solid-liquid ratio is 1:5 - 20.

[0034] In this step, with stirring, add copper hydroxychloride solid to the prepared ammonium bicarbonate solution to obtain a mixed solution, where the solid-liquid ratio is 1:5 - 20, and the mass ratio of copper hydroxychloride to ammonium bicarbonate is 1:0.8 - 1.5. Preferably, the solid-liquid ratio is 1:8. In addition, with the solid-liquid ratio kept constant, copper hydroxychloride solid can also be added first, and then the ammonium bicarbonate solution.

[0035] S3: Heat up and keep warm the mixed solution obtained in S2 to obtain a suspension of basic copper carbonate precursor.

[0036] In this step, in the reaction kettle, heat up the suspension of basic copper carbonate precursor to between 30 - 45 °C, preferably 40 °C. Subsequently, after reaching the predetermined temperature, keep warm for 1 - 5 h to obtain a suspension of basic copper carbonate precursor.

[0037] S4: Continue to heat up and keep warm the suspension of basic copper carbonate precursor obtained in S3 to obtain a basic copper carbonate liquor.

[0038] In this step, in the reaction kettle, continue to heat up the suspension of basic copper carbonate precursor to between 40 - 90 °C, preferably 80 °C, and control the pressure in the reaction kettle between 0 - 0.4 MPa. Subsequently, keep warm for 1 - 5 h to obtain a basic copper carbonate liquor. The relevant reaction equations are as follows:

[0039] 3Cu2(OH)3Cl + 3NH4HCO3 + CO2 → 2Cu3(OH)2(CO3)2 + 4H2O + 3NH4Cl,

[0040] The conversion equations between CuCO3·Cu(OH)2 and 2CuCO3·Cu(OH)2 are as follows. In the case of sufficient carbon dioxide, CuCO3·Cu(OH)2 can be converted to 2CuCO3·Cu(OH)2. In the present invention, the excessive ammonium bicarbonate mainly plays two roles. One part of the ammonium bicarbonate reacts with copper hydroxychloride to form CuCO3·Cu(OH)2, and the other part of the ammonium bicarbonate releases carbon dioxide during the thermal decomposition process. The carbon dioxide reacts with CuCO3·Cu(OH)2 to form 2CuCO3·Cu(OH)2, that is:

[0041] 3Cu2(OH)2CO3 + CO2 → 2Cu3(OH)2(CO3)2 + H2O.

[0042] S5: Perform solid-liquid separation, washing, and drying on the copper basic carbonate liquor obtained in S4 to obtain blue copper basic carbonate powder.

[0043] In this step, first pump the copper basic carbonate liquor into a separator for solid-liquid separation. Subsequently, use water slurrying to wash the solid obtained from solid-liquid separation 1 - 5 times. Finally, dry the washed solid at a temperature between 60 - 120 °C for 2 - 6 h to obtain blue copper basic carbonate powder.

[0044] The present invention adopts a chemical synthesis method to stably synthesize 2CuCO3·Cu(OH)2, solving problems such as poor repeatability in the extraction of natural blue copper basic carbonate, cumbersome extraction process, and unstable impurities. At the same time, this method has simple operation and good operating conditions, and can prepare a stable blue copper basic carbonate product by a one-step method. Among them, the conversion rate of Cu is between 70 - 85%. In addition, the obtained blue copper basic carbonate has lower impurity content and stable composition compared with the copper basic carbonate extracted from nature.

[0045] The following is illustrated with specific examples:

[0046] Example 1:

[0047] 1) Weigh 25 kg of copper basic chloride solid and slurry it with 200 L of water;

[0048] 2) Add 23 kg of ammonium bicarbonate solution to the copper basic chloride slurry obtained in (1) to obtain a mixed solution;

[0049] 3) Heat the mixed solution to 40 °C and react for 2 h to obtain a suspension solution of copper basic carbonate precursor;

[0050] 4) Heat and raise the temperature of the precursor suspension solution obtained in (3), and raise the kettle temperature to 85 °C. After holding for 1.5 h, stop heating to obtain copper basic carbonate liquor;

[0051] 5) Drain the liquor, perform solid-liquid separation, wash the solid once with water, and dry it at 100 °C for 4 h to obtain 19 kg of blue solid powder.

[0052] Example 2:

[0053] 1) Inject 200 - 250 L of water into the reaction kettle and add 27 kg of ammonium bicarbonate solid (slowly add until completely dissolved);

[0054] 2) Add 27 kg of copper basic chloride solid to the ammonium bicarbonate solution obtained in (1);

[0055] 3) Raise the kettle temperature to between 40 °C and hold for 1.5 h to obtain a suspension of copper basic carbonate precursor;

[0056] 4) Heat the suspension of the basic copper carbonate precursor to 80 °C, keep it warm for 3 h, then stop heating to obtain the basic copper carbonate feed liquid;

[0057] 5) Separate the solid from the liquid in the feed liquid, wash the solid three times with water, and dry it at 90 °C for 5 h to obtain 20.1 kg of blue solid powder.

[0058] Example Cu% Cl％ Na% Fe% Pb% Zn% Ca% Cr％ Cd% As% One 54.35 0.093 0.0025 0.0018 ND 0.0015 0.0015 0.0007 ND ND Two 54.49 0.046 0.0012 0.0016 ND 0.0016 0.0014 0.0012 ND ND

[0059] Table 1 Test table of the products obtained in the above two examples

[0060] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for preparing a basic copper salt, characterized in that, It includes the following steps: S1: Prepare an ammonium bicarbonate solution; S2: Add solid copper hydroxide chloride to the ammonium bicarbonate solution, or pour the ammonium bicarbonate solution into the solid copper hydroxide chloride to obtain a mixed solution, where the solid-liquid ratio is 1:8; S3: Heat up and keep the temperature constant for the mixed solution obtained in S2 to obtain a suspension of basic copper carbonate precursor; S4: Continue to heat up and keep the temperature constant for the suspension of basic copper carbonate precursor obtained in S3 to obtain a basic copper carbonate liquor; S5: Conduct solid-liquid separation, washing, and drying on the basic copper carbonate liquor obtained in S4 in sequence to obtain blue basic copper carbonate 2CuCO3•Cu(OH)2 powder; In S1, first pour a predetermined volume of water into the reaction kettle, and then add solid ammonium bicarbonate and stir to obtain an ammonium bicarbonate solution, where the pH value of the ammonium bicarbonate solution is 7-10; In S3, first in the reaction kettle, heat up the mixed solution obtained in S2 to 30-45 °C, and then keep the temperature constant for 1-5 h; In S4, first in the reaction kettle, continue to heat up the suspension of basic copper carbonate precursor to 80-90 °C, and then keep the temperature constant for 1-5 h.

2. The preparation method of the basic copper salt according to claim 1, characterized in that, In S4, heat up the suspension of basic copper carbonate precursor to 80 °C; the pressure in the reaction kettle is controlled between 0-0.4 MPa.

3. The preparation method of the basic copper salt according to claim 1, wherein In S5, pump the basic copper carbonate liquor into a separator for solid-liquid separation.

4. The preparation method of the basic copper salt according to claim 1, characterized in that, In S5, wash the solid obtained by solid-liquid separation 1-5 times with water slurrying.

5. The preparation method of the basic copper salt according to claim 1, characterized in that, In S5, dry the washed solid at 60-120 °C for 2-6 h.

6. The preparation method of the basic copper salt according to claim 1, wherein In S3, heat up the mixed solution obtained in S2 to 40 °C.

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