JPS6047207B2 - Method for producing cupric hydroxide - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing high-purity cupric hydroxide using cupric chloride, copper etching wastewater using cupric chloride, cupric ammonium chloride, etc. as raw materials. It is.

Cupric hydroxide is a blue crystalline powder that is expensive and useful as a raw material for ship bottom paints, agricultural chemicals, etc.

Conventionally, methods for producing cupric hydroxide have been carried out using copper sulfate as a raw material, but specifically, (a) a method for obtaining cupric hydroxide by adding caustic soda to ammonium sulfate double salt (U.S. Patent No. 1,800,828) (b) A method of obtaining cupric hydroxide by adding a caustic sorter to a double salt of copper sulfate and trisodium phosphate (US Pat. No. 2,666,688).

In method (a), ammonia water is added to a copper sulfate solution to obtain a deep purple solution of cupric ammonium sulfate double salt, a caustic soda aqueous solution is added to this to precipitate cupric hydroxide, and the product is separated by filtration. do.

The reaction formula is as follows. CuS04+4NH4
OH →CU(NHa)4SO4+4H2O CU(NH3)4S04+2NaOH+4H2O″ →
CU(OH)2+Na2SO4+4NH4OHAs is clear from the above reaction formula, 4 mol per mol of copper sulfate
1 of ammonia is required, and the filtrate obtained by filtering cupric hydroxide contains approximately 20% copper ammonium sulfate double salt, mirabilite,
and ammonia are dissolved7.

Since the ammonia can be recycled and used, when the raw material copper sulfate is newly added to the filtrate and a second reaction is performed by adding caustic soda, hydroxide corresponding to the newly added copper sulfate is generated. Cupric acid is obtained, but as in the previous case, approximately 20% cupric ammonium sulfate double salt and two doses of Glauber's salt are dissolved in the filtrate, and the liquid volume further increases, so the concentration becomes slightly diluted. When the number of sequential reactions increases in this manner, a large amount of Glauber's salt is produced and the yield of cupric hydroxide increases slightly, but the crystal grains become fine and the blue color becomes weak and unstable, resulting in a decrease in quality. Therefore, in this method, it is necessary to cool the reaction after repeating the reaction at least twice to remove the Glauber's salt crystals.
In addition, when separating the crystals of Glauber's salt, the liquid adhering to the crystals, that is, the liquid containing some copper ammonium sulfate double salt and ammonia, cannot be recovered and is discarded as wastewater, which poses problems in the treatment of wastewater. There is. Next, method (b) is carried out according to the following reaction formula.

That is, a calculated amount of trisodium phosphate solution is added to a copper sulfate solution to make a copper sodium phosphate double salt, and a caustic soda solution is added to this to obtain a precipitate of cupric hydroxide. Since trisodium acid can be used in circulation, the first reaction is carried out using a large vessel that can accommodate several reaction volumes without immediately separating the cupric hydroxide precipitate. To the solution in which the reaction has been completed and a precipitate has been formed, add the second copper sulfate in its crystal form to form a double salt with the free trisodium phosphate, and add a caustic soda solution to the solution to form a precipitate. A precipitate of cupric oxide is obtained.

After repeating the reaction in this manner to the extent permitted by the container, the cupric hydroxide is filtered off, while the filtrate containing trisodium phosphate is subjected to a new reaction by adding copper sulfate. , forming a copper phosphate sorter double salt and starting a new reaction.
Cupric hydroxide produced by this method; copper has a slightly bluish color and is unstable, and the copper-sodium phosphate double salt forms a gel-like precipitate, making it difficult to recover cupric hydroxide. There is a problem that filtration is difficult. As a result of intensive research in order to overcome the problems of the prior art, the present invention uses cupric chloride and/or an aqueous solution containing it as a main component as a raw material, thereby making it difficult to dehydrate. The present invention has been completed by discovering a method for obtaining high-yield cupric hydroxide with good storage stability and high purity.

That is, the present invention is a hydroxide method characterized by reacting cupric chloride or/and an aqueous solution containing it as a main component with ammonia to produce a cupric ammonium chloride double salt, and then reacting the salt with a caustic alkali. This is a method for producing cupric copper.

As the raw material of the present invention, cupric chloride or/and an aqueous solution containing it as a main component is used, but an aqueous solution containing cupric chloride as a main component contains cupric chloride as a main component Although the type of aqueous solution is not limited as long as it is present, an aqueous solution of copper chloride etching treatment waste liquid and/or copper ammonium chloride crystals [CuCl22NH4Cl2ll2O] is usually used. The copper chloride etching process waste liquid is a process waste liquid obtained by etching a copper printed wiring board using an aqueous solution of cupric chloride, and its composition usually contains the following: Some other organic substances, Ni. Zn
．． This includes PO4- ions and the like.

Etching of printed wiring boards is carried out using the following reaction mechanism when cupric chloride is used. This temperature is 0℃
When the concentration of 1 becomes high, water solubility disappears and sludge is generated, so either stop using it until the amount of CuCl does not increase too much, add HCl and perform air oxidation, or add NaCl. In order to prevent the generation of cuprous chloride sludge, either a complex is made into a water-soluble form by molding cuprous chloride saline or the like.

Therefore, the solution has a composition containing cupric chloride and can be used in the present invention. Next, the manufacturing method of the present invention using the above raw materials will be explained in detail.

Add more than the calculated amount of ammonia water to the above-mentioned raw material copper chloride solution or a solution containing some hydrochloric acid, such as copper chloride etching wastewater or/and cupric ammonium chloride crystal aqueous solution at room temperature, and make the following. The reaction produces a solution of copper ammonium chloride double salt.

In this reaction, ammonia equivalent to 2n101 or more is required for 1m01 of cupric chloride in the raw material.

At this time, if the raw material solution contains hydrochloric acid, a corresponding amount of ammonia is added. However, f-HCl indicates free hydrochloric acid.

The reaction solution initially changes from a green precipitate to a purple precipitate by adding ammonia, and when the calculated amount is added, it becomes a dark purple and transparent solution.

Next, for example, caustic soda is added as a caustic alkali in an amount equal to or more than the added ammonia, and a precipitate of cupric hydroxide is generated by the following reaction. &LA■Fyl! A1 V
A 1 Todoroki 4 CkV issue ● -1 - The cupric hydroxide precipitate obtained is filtered, washed with water, and dried to produce a product, but the yield is usually about 85% and the remainder is dissolved in the filtrate. .

The remaining copper ammonium chloride double salt, common salt, and ammonia are dissolved in the filtrate, and the filtrate is heated to evaporate and recover the ammonia, which is used as the next raw material for cupric chloride and/or it. The copper ammonium chloride double salt remaining in the filtrate decomposes into a black precipitate of cupric oxide, which is filtered and dissolved in hydrochloric acid. and return to the raw material solution. Therefore, the filtrate becomes a colorless and transparent solution containing only common salt. The caustic alkali used in the present invention includes caustic soda and caustic potash, but it is more advantageous to use caustic soda because it is usually inexpensive and the reaction product is common salt and can be easily treated.

In order to reuse ammonia, the filtrate from which the cupric hydroxide precipitate has been separated is heated, but the heating temperature needs to be above the temperature at which ammonia evaporates, and is usually 80 to 95%.
It is ℃.

In this way, the present invention uses a cupric chloride solution to the copper sulfate solution conventionally used as a raw material, and adds half the amount of ammonia compared to the conventional method to produce cupric ammonium chloride double salt. It is produced and further neutralized with caustic soda, and cupric hydroxide crystals can be obtained by filtration.

In addition, the ammonia remaining in the filtrate can be evaporated by heating, absorbed into the raw material liquid, recovered, and reused. can be dissolved in hydrochloric acid and returned to the raw material for use. The final filtrate is recovered as an aqueous solution containing only common salt. Next, the effects of the present invention are listed below.

(1) In the case of the conventional method using copper sulfate as a raw material, 1 m of copper
4m01 of ammonia is used for 01, but in the case of the present invention using cupric chloride, 2n1 is used for 1m01 of copper.
Since the reaction is carried out with 01 ammonia, the amount of ammonia consumed is small in the present invention.

(2) The ammonia that evaporates by heating the filtrate from which cupric hydroxide has been separated is absorbed into the copper chloride aqueous solution to be used next time and reused.The salt dissolved in each reaction is generated by the reaction of that reaction. 6, and there is no deterioration of the product due to salt accumulation. (3) Ammonia gas absorption by a cupric chloride solution is very efficient and completely captures ammonia gas, so even if there is a slight excess of ammonia, there is little chance of it escaping.

Next, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

Example 1 21.29 kg of copper chloride (10.01 k9 as copper amount),
1 containing 1.90 kg of free hydrochloric acid (hereinafter referred to as f-hydrochloric acid)
20e solution, ammonia water with a concentration of 2% by weight 56.3
5e was added.

In this case, the amount of ammonia added was approximately 10% in excess of the calculated amount of 2rr101 per 1 m01 of copper and 1 m0I per 1 m0I of hydrochloric acid. To the obtained solution containing the double salt of copper chloride and ammonia and ammonium chloride, 14.76k9 of caustic soda was added as a solution of about 2% by weight over about 1 hour. In this case, the amount of caustic soda is approximately equivalent to the amount of ammonia added. Further, the reaction was continued for about 3 minutes, and the precipitate of cupric hydroxide obtained was filtered, the adhering liquid was dropped into the filtrate with a small amount of water, and the precipitate was transferred to a washing tank and washed with water. After filtration and drying, a cupric hydroxide product was obtained. Yield 13.
01k9, yield 84.22%. The filtrate was transferred to another container, and a device was constructed to introduce the generated ammonia into the cupric chloride aqueous solution to be used next time.
．． Ammonia gas generated by heating for a period of time was absorbed into an aqueous solution of cupric chloride to be used in the next Example 2. The black copper oxide obtained at this time had a yield of 1.74 kg and a yield of 13
．． It was 81%. Example 2 Using the same copper chloride raw material liquid as in Example 1, the total liquid volume was diluted to 200e.

(The composition is copper chloride 21.29kg, f hydrochloric acid 1.90k9,
Liquid volume: 200e) The ammonia gas recovered in Example 1 was absorbed into this liquid. 14. Caustic soda as in Example 1.
76 kg was added as an approximately 20% by weight solution to precipitate cupric chloride, and the same procedure as in Example 1 was carried out to obtain cupric hydroxide. Yield: 12.75k9, yield: 82.55%. Further, the black copper oxide obtained when the ammonia generated by heating the filtrate after product separation to 90 to 95°C was absorbed into the raw material aqueous solution of copper chloride in Example 3 had a yield of 2.15k9. It was 17.07%. Example 3 Copper chloride 21.29 kg, f hydrochloric acid 1.90k9, liquid volume 15
The ammonia gas recovered in Example 2 was absorbed into the raw material solution of 0e, and 14.76k of caustic soda was added in the same manner as in Example 1.
9 was added as a solution of about 2% by volume to obtain cupric hydroxide.

Yield: 13.28k9, yield: 85.98%. In addition, the black copper oxide obtained when the ammonia in the filtrate was recovered by heating and absorbed into the raw material solution of Example 4 had a yield of 1.62.
k9, yield 12.86%. Example 4 Copper chloride 21.
29k9, f hydrochloric acid 1.90k9, liquid volume 150' fruit. The ammonia gas recovered in Example 3 was absorbed into a raw material solution with the same composition as in Example 3, and in the same manner as in Example 1, caustic soda was increased to 16k9 and added as a solution with a concentration of about 2% by weight. Cupric oxide was obtained.

The yield was 13.28k9, and the yield was a. It is 98%. This hydric acid! The quality of cupric oxide is the same as that of the products of Examples 1 to 3, and the quality is not affected even if caustic soda is used in excess. Further, the yield of black copper oxide obtained when ammonia was recovered was 1.54k9, and the yield was 12.22%. Examples 5 to 7 Copper chloride 21.
The ammonia recovered in the previous step (Example) was absorbed into a raw material aqueous solution containing 29 kg of hydrochloric acid and 1.90 kg of hydrochloric acid, and treated with 14.76 k9 of caustic soda.

The results of Examples 1 to 7 are summarized in Table 1. However, in Examples 1 to 7, when the solution in which the aqueous cupric chloride solution, which was the raw material in Example 6, absorbed the ammonia recovered by heating in Example 5, a slight purple precipitate was observed when it was allowed to stand still. Therefore, the ammonia that was added in excess of 10% in Example 1 was lost, and since the ammonia was recycled five times, the average loss per time was about 2%. The cause of this loss is that suction filtration was used when filtering the product), and it is mainly the exhaust gas that is emitted during this process.If the exhaust gas is introduced into the raw material liquid and absorbed, ammonia can be removed. Escaping can be almost completely eliminated. Comparative Example 1 As a comparative example, a method for producing cupric hydroxide using copper sulfate as a raw material (U.S. Pat. No. 18
The results of an experiment conducted using the method of No. 00828 are shown below.

To an aqueous solution in which 40 kg of copper sulfate (CUSO45F [20) was dissolved in 160 e of water, 98 e of 2% ammonia water was added (approximately 10% excess).

Further, an aqueous solution of 14 kg of caustic soda dissolved in 501 water was added to precipitate cupric hydroxide, and the mixture was cooled to 6°C to precipitate Glauber's salt crystals, which were filtered together with cupric hydroxide.
Because Glauber's Salt is soluble in water, we did not perform an operation to recover the cupric hydroxide precipitate and the adhering liquid of Glauber's Salt crystals through water. The cupric hydroxide was separated from the mirabilite by washing with water, washed and dried, but the product had exactly the same appearance as the product of the example in which copper chloride was used as the raw material. Yield 10.99k9, yield 70.
It was 29%. The remaining copper content (approximately 30%) remains in the filtrate with a yield of 70.29%. Comparative Example 2 Copper sulfate 40k9 was added and dissolved in the filtrate of Comparative Example 1, and an aqueous solution of caustic soda 13.5k9 dissolved in 50e of water was added and treated in the same manner as Comparative Example 1 to obtain cupric hydroxide. .

The yield is 15.75k9, and the yield is 100.73%. Approximately the same amount of copper (approximately 3
0%) remains in the filtrate without becoming a precipitate. Ru.
Comparative Example 3 Copper sulfate 40k9 was added and dissolved in the filtrate of Comparative Example 2, and an aqueous solution of caustic soda 13.5k9 dissolved in 50e of water was added and treated in the same manner as Comparative Example 1 to obtain cupric hydroxide. Obtained.

The yield is 15.85k9, and the yield is 101.37%. This means that a little less than 30% of the copper content remains in the filtrate. Comparative Example 4 Copper sulfate 40k9 was added and dissolved in the filtrate of Comparative Example 3, and an aqueous solution of caustic soda 13.5k9 dissolved in 50e of water was added to precipitate cupric hydroxide, which was then filtered at a filtration temperature of 25
It was filtered at ℃ without precipitation of Glauber's salt crystals.

The resulting yield of cupric hydroxide was 16.02k9
, yield was 105.02%. Therefore, when the produced mirabilite is dissolved, the amount of copper remaining in the filtrate is approximately 2
It is 5%. Comparative Examples 5 to 7 The same method as in Comparative Example 4 was conducted except that 40k9 of copper sulfate and 13.5k9 of caustic soda were added to the filtrate obtained in the previous comparative example.

The filtration temperature of the cupric hydroxide precipitate obtained is about 25°C. The results of Comparative Examples 1 to 7 are summarized in Table 2.

In Comparative Examples 4 to 7, since the filtration was carried out at a filtration temperature of about 25°C, the dissolved amount of Glauber's salt gradually increased, and as a result, the color tone of the cupric hydroxide in the product gradually became less bluish and the crystal particles became finer. This resulted in a product with a high bulk and therefore easily converted to copper oxide. Therefore, in order to maintain uniformity in product quality, in the method of this comparative example, it is necessary to cool the filtrate at least once every two times to discharge the Glauber's salt crystals. Furthermore, in the case of circulating and reusing ammonia, the filtrate of Comparative Example 4 ran out of ammonia, and 311 in Comparative Example 5 and 2e in Comparative Example 6 were added.

Therefore, compared to Examples 1 to 7 in which copper chloride of the present invention was used as a raw material, the loss of ammonia was large, and this loss was due to the 7
It can be concluded that the difference between the two is due to the copper solution used. Next, the above example and comparative example will be compared.

In the method of the present invention, ammonia is recovered by heating and recycled for use, whereas in the copper ammonium sulfate method of the comparative example, it is necessary to separate the sodium sulfate by cooling. The cupric ammonium sulfate method has higher losses of copper and ammonia.

Claims (1)

[Claims] 1. A process characterized by reacting cupric chloride or/and an aqueous solution containing it as a main component with ammonia to produce cupric ammonium chloride double salt, and then reacting the salt with a caustic alkali. A method for producing cupric hydroxide. 2. The method for producing cupric hydroxide according to claim 1, which uses a copper chloride etching treatment waste liquid and/or an aqueous solution of cupric ammonium chloride crystals [CuCl_22NH_4Cl2H_2O] as the aqueous solution containing cupric chloride as the main component. 3. Copper ammonium chloride double salt is produced by reacting cupric chloride or/and an aqueous solution containing it as a main component with ammonia, and then reacting the salt with caustic alkali to obtain cupric hydroxide precipitate; Production of cupric hydroxide, which is characterized by recovering ammonia by heating the filtrate after filtering it, and repeatedly reacting the ammonia with cupric chloride or/and an aqueous solution containing it as a main component. Method. 4. The method for producing cupric hydroxide according to claim 3, which uses a copper chloride etching treatment waste liquid and/or an aqueous solution of cupric ammonium chloride crystals [CuC_22NH_4Cl2H_2O] as the aqueous solution containing cupric chloride as a main component.