BG62204B1 - Method for chemical regeneration of the components of copper-ammonia solutions from alkaline etching - Google Patents

Abstract

The method is used in the chemical industry, in particualr inelectrical engineering for the technological regeneration of thecomponents of the copper-ammonia waste solutions from alkalineetching. It is simplified and cheap and includes the use of widelyaccessible reagents where the copper and chlorine compounds aswell as the ammonia liquor produced during the regeneration arecompletely usable in the chemical industry and agriculture. Themethod consists in the treatment of waste waters with sodium orpotassium base, or with hydrochloric or nitric acid in dry form orin the form of solutions in alkaline (hydrogen) cation: generalcopper in the solution ratio of 0.01-0.1 : 15. The temperature isthen raised to 40-100°C until the complete separation of thechlorine ions, it is dried and subjected to heat treatment at 40to 500°C for 6 to 24 h.1 claim

Description

(54) METHOD FOR THE CHEMICAL REMEDIATION OF THE COMPONENTS OF WASTE AND COPPER-AMMONIAL SOLUTIONS FROM ALKALINE EATING

Technical field

The invention relates to a method for the recovery of components of waste and copper-ammonia solutions of alkaline pickling, which can be used in the chemical industry for the recovery of the products obtained in this process - copper and chlorine compounds and ammonia water.

BACKGROUND OF THE INVENTION

Methods are known for recovering the components of waste copper-ammonia solutions from the alkaline etching of PCBs [1-4], in which regeneration is carried out by electrolysis of the solutions to:

(a) a cathode residue consisting of copper powder or slurry of varying degrees of compaction deposited on a cathode shaped as a disk to facilitate the removal of copper from its surface [3]; and

b) the anode accumulation of chlorine-containing compounds.

The main disadvantages of these methods are high power consumption, sophisticated equipment, the need for additional equipment to absorb chlorine and the need for pre-dilution of the solutions, which increases the volume of the installation several times.

Methods are known for treating copper-ammonia alkaline pickling waste solutions [5,6], in which the copper contained therein is regenerated by treatment with activated carbon or graphitized monomers containing carboxy groups. In these methods, the reagents are more expensive and the cost of energy-increased (for pre-calcination from 900-1200 ° C on carbon).

Methods for regenerating these etching solutions [7,8] using ion-exchange resins or organic reagents are also known. These methods use flammable and explosive reagents, complicating the technology.

SUMMARY OF THE INVENTION

The method for the chemical regeneration of alkaline copper etching solutions according to the invention is that the waste solutions are treated with bases such as sodium or potassium, or with inorganic acids such as hydrochloric, nitric or sulfur, in the dry state or with their aqueous solutions at an alkali (hydrogen) cation: total copper ratio of 0.01-0.15: 15, after which the temperature is increased from 40 to 100 ° C until complete separation of the ammonia from the system is absorbed into the sorption unit, and then The solution was filtered and the resulting precipitate was washed to complete separation of chlorine ions with subsequent thermal treatment to a temperature of 40 to 500 ° C for 6 to 24 b.

The method according to the invention has the following advantages: reduced energy costs, simplified apparatus, use of available reagents that are harmless. The substances obtained after the regeneration of the waste solutions (copper compounds with chemical purity, ammonia water and chlorides) are fully utilized.

An exemplary embodiment of the invention

The method according to the invention is illustrated by the following examples.

EXAMPLE 1 To a 4 l waste copper-ammonia etching solution containing 27.5 g / l copper, a 1.26 k g / 20% sodium hydroxide solution was added and the temperature increased from 60 to 80 ° S. The thermal treatment is continued until complete separation of the ammonia from the solution. After filtration, washing the precipitate in the absence of chlorine ions and drying at 60 ° C for 24 b. Obtained Cu (OH) ₂ in 130 lbs.

EXAMPLE 2 To a 60 I waste etching solution containing 108.6 < 1 > copper, 8.3 [mu] l of sodium hydroxide base were added. The temperature was raised from 60 to 80 ° C until complete removal of the ammonia contained in the system was absorbed into the sorption column with 20 l of recycling water. The resulting suspension was filtered and the precipitate was washed with no chlorine ions. Drying at 80 ° C followed by thermal treatment at 250 ° C for 10 b. A mixture of 7.35 k§ of copper oxide is obtained. Recycling water analysis showed an ammonia concentration of 10.95% by weight.

Example 3 To 200 l of waste copper ammonia solution was added 25 kg of sodium hydroxide base. It was done as in Example 2, but the thermal treatment was carried out at 450 ° C for 6 b. 27 lb. of CIO is obtained.

Example 4. To a 60 I waste etching solution with a copper concentration of 120 [mu] g / l was added 8 kPa potassium granules. The treatment was analogous to that of Example 1. Copper hydroxide was obtained in an amount of 8.1 k§.

Example 5. To 150 l of waste copper ammonia solution at a concentration of 105.6 < 1 > The processing technology is similar to that in Example 1. Copper hydroxide is obtained in an amount of 22 kPa. The solution after separation of the precipitate has a chlorine ion concentration of 185.7 β / l.

Example 6 To 180 l of copper-ammonia etching waste solution at a concentration of 115 l / l copper was added 40 1 55% sulfuric acid. Work as in example 1. Obtained copper hydroxide in the amount of 36.5 kPa. The solution after separation of the precipitate contains chlorine ions at a concentration of 98.2 β / l and sulfate ions 134 lb / l.

EXAMPLE 7 50 1 47% nitric acid was added to 170 l of waste copper ammonia with a concentration of 120 < 1 > Work as in example 1. Obtained copper hydroxide 28.5 k§. The solution after separation of the precipitate has a chlorine ion concentration of 92.7 § / l and nitrate ions of 13.8 < / RTI > / 1.

Application of the invention

As a result of the practical application of the process according to the invention, full recovery of the waste water components from the alkaline etching of copper is achieved. The solutions obtained contain copper in the form of copper hydroxide or copper oxides, which are categorized as "pure" chemical products, which are suitable for the preparation of the full range of copper compounds for use in the chemical, agricultural and other industries. Chlorine ions remain in solution after separation of the precipitate in combination with part of the ammonia and possibly sulfate and nitrate ions. The performance of this solution is such that it can be successfully reused in the copper etching process by adding it to freshly prepared solutions. Part of the ammonia contained in the solution is desorbed and swallowed with water to produce ammonia water with a concentration above 10% and is categorized as a "technically pure" chemical product that can be applied wherever a standard 25% is used of ammonia water.

Claims (1)

Claims A method for chemical recovery of the components of a copper-ammonia waste alkali etching solution, characterized in that the waste solutions are treated with sodium or potassium hydroxide or with hydrochloric, sulfuric or nitric acid in the dry state or in the form of a solution in a ratio of alkaline (hydrogen) cation: copper in solution = 0.01-0.15: 15, then the temperature rises from 40 to 100 ° C until the ammonia is completely removed from the sorption unit and the solution is then filtered and the resulting precipitate washed to completion But separating the chloride ions, dried and subjected to thermal treatment at a temperature of 40 to 500 ° C for 6 to 24 hours.