KR20020003454A - Process for cupric sulfate monohydrate - Google Patents

Abstract

PURPOSE: A process for preparing cupric sulfate monohydrate(CuSO4·H2O) from waste etchant, which is generated in the manufacture of Printed Circuit Board(PCB) and comprises copper chlorides. CONSTITUTION: Calcium carbonate powder(CaCO3) is added in waste etchant comprising copper chlorides to basic copper carbonate. After obtaining copper carbonate cake by washing and filtration, dry the cake in the temperature range 150 to 160deg.C to completely remove moisture content. When the dried copper carbonate cake is heated, 3-8wt.% of the copper carbonate is changed into copper chlorides. The copper carbonate powder is added with condensed sulfuric acid in an amount corresponding to equivalence of copper content under stirring, and thus yield cupric sulfate monohydrate(CuSO4· H2O).

Description

Method for producing copper sulfate monohydrate {PROCESS FOR CUPRIC SULFATE MONOHYDRATE}

The present invention relates to a method for producing copper sulfate monohydrate (CuSO ₄ 1H ₂ O) from waste liquid containing copper chloride. More specifically, the present invention relates to a method of preparing copper sulfate monohydrate by heating copper carbonate (CuCO ₃ ) obtained by neutralizing a waste liquid containing copper chloride with calcium carbonate, drying, and adding concentrated sulfuric acid. This copper sulfate monohydrate is added to animal medicines for the purpose of supplying minerals to animals.

In recent years, due to the development of the electronics industry, a large amount of waste liquid for corrosion of electronic circuit boards is generated.

If this waste liquid is left untreated or disposed of, it causes air pollution, rivers, soil, etc. to become a socially large environmental problem. Therefore, measures are being taken to prevent environmental pollution by recycling waste liquid and to utilize it as a new resource. Since this waste liquid contains about 15 to 20% of copper chloride, a plan has been devised for use as a product such as copper cyanide (CuCN) and copper sulfate from the waste liquid. However, copper cyanide is not consumed much, and there are many difficulties in producing copper sulfate. That is, copper hydroxide, copper carbonate and copper oxide obtained by neutralization by adding sodium hydroxide, sodium carbonate, slaked lime and calcium carbonate to the copper chloride-containing waste solution are washed with water, and diluted sulfuric acid is added to form copper sulfate pentahydrate. Copper sulfate pentahydrate was dried to prepare copper sulfate monohydrate, or copper sulfate pentahydrate was prepared by adding nitric acid-sulfuric acid to copper powder such as copper scrub and dissolving to produce copper sulfate pentahydrate crystal, dehydrating and drying at 200 ° C. . This manufacturing method has the drawback that the process is complicated and expensive.

To the copper chloride-containing waste liquid, an equivalent ratio of sulfuric acid was added and stirred, followed by heating and concentration to remove hydrochloric acid, copper sulfate was recovered and recrystallized several times to prepare copper sulfate pentahydrate. However, in such a method, the reactor is expensive to manufacture by adding sulfuric acid and concentrated, and the durability of the reactor becomes weak, and when a crack occurs in the reactor, problems related to the reactor such as the reactor itself explode are always present. It is implicated.

In addition, it was neutralized by adding a zinc material to the copper chloride waste solution, and zinc sulfate was added to react with copper chloride to obtain zinc chloride and copper sulfate, and a method of treating this with alcohol to separate zinc chloride and copper sulfate (patent application 2000- 11877). However, since this method does not generate hydrochloric acid as compared with the prior art, the recovery apparatus is inexpensive and safe, but there is a problem that the production cost is high due to the recent increase in the price of zinc materials.

Therefore, the present inventors have studied to improve the above-described method, and as a result, neutralized by using inexpensive calcium carbonate and sodium hydroxide in a waste liquid containing copper chloride to obtain crude basic copper carbonate and crude copper hydroxide. The crude basic copper carbonate is dried by heating to obtain a copper carbonate powder containing a small amount of copper oxide. When the copper carbonate powder containing copper oxide was treated with concentrated sulfuric acid, it was found that copper sulfate monohydrate was immediately produced by the reaction heat, and thus the present invention was completed.

The present invention relates to a method for producing copper sulfate monohydrate that can be added to animal feed as mineral chemicals using copper chloride in the waste liquid as the raw material for the corrosion of electronic circuit board corrosion in the electronics industry.

Neutralization by adding calcium carbonate (CaCO ₃ ) powder to the waste liquid containing copper chloride produces crude basic copper carbonate containing copper hydroxide. The reaction solution is filtered and washed with water to obtain a crude basic copper carbonate cake, and dried completely at 100 to 200 ° C, preferably at 150 to 160 ° C to obtain a powdered state. At this time, 3-8% is converted to copper oxide by heating and drying . Crude copper carbonate powder is added to a ball mill type reactor or a shuffle mixer reactor, and concentrated sulfuric acid corresponding to the equivalence ratio of the same content is slowly added under stirring to prepare copper sulfate monohydrate.

When concentrated sulfuric acid is added to the raw material of crude copper carbonate or copper oxide directly under agitation and reacted, when the temperature is raised to 130-140 ° C by reaction heat, 80 to 100 mesh of white powder copper sulfate monohydrate is produced directly. In this reaction, the stirring speed and homogeneous mixing ability affect the purity of copper sulfate monohydrate. The stirring speed may be about 1000 to 400 rpm, preferably 600 rpm.

Example 1

300 g of crude copper carbonate dried powder (copper content 51.3% 154 g) containing 5% copper oxide was added to a grinder, and 240 g of concentrated sulfuric acid was added three times while stirring at 600 rpm, and reacted for 30 minutes while maintaining the reaction temperature at 160 ° C. 435 g of (CuSO 4 _˙ H ₂ O) were obtained.

Example 2

Copper oxide (CuO) a dry powder (copper content 79%) 300g while the blender and placed in a stirred In the split three times a concentrated sulfuric acid 370g and allowed to react at 170 ℃ was reacted for 30 minutes copper sulfate monohydrate (CuSO _4˙ H ₂ O) 670 g were obtained.

The reaction of crude basic copper carbonate or crude copper oxide obtained by adding calcium carbonate or sodium hydroxide to the waste liquid for PCP substrate corrosion is carried out with the addition of concentrated sulfuric acid under agitation, thereby directly producing copper sulfate monohydrate (CuSO _4˙ H ₂ O) due to the heat of reaction. . Therefore, rather than the known method of preparing copper sulfate pentahydrate by adding sulfuric acid to the waste liquid and heating copper dehydrated copper sulfate to produce copper sulfate monohydrate, the present invention does not require a dehydration process, which reduces production costs and shortens manufacturing time. Invention.

Claims (1)

In the method for producing copper sulfate using a neutralizing agent calcium carbonate or sodium hydroxide in a PCP substrate corrosion waste solution containing copper chloride (CuCl ₂ ), _Process for preparing copper sulfate monohydrate (CuSO _4˙ H ₂ O) characterized by reacting concentrated sulfuric acid with crude basic copper carbonate or copper oxide without solvent