Metal extraction from waste slag

With the continuous development of urbanization, the problem of garbage is becoming increasingly prominent, and garbage slag has become a major problem. Waste slag refers to the residue generated during Incineration, which contains a large number of metal elements, such as copper, aluminum, iron, etc. These metal elements have high recycling value, but due to the complexity of waste slag, it is difficult to effectively extract the metal elements from the slag. This article will introduce a method of metal extraction from garbage slag, hoping to play a guiding role in garbage slag treatment and Recycling.

Composition of waste slag

Waste slag refers to the residue generated during Incineration, which contains a large number of metal elements, such as copper, aluminum, iron, etc. The composition of garbage and slag is very complex, including various components such as organic matter, inorganic matter, metal elements, etc. The main components of waste slag are as follows:

1. Inorganic: including alumina, silicon oxide, Calcium oxide, magnesium oxide, etc.

2. Organic matter: including organic acids, fatty acids, proteins, cellulose, etc.

3. Metal elements: including copper, aluminum, iron, zinc, lead, etc.

Due to the complexity of waste slag, it is difficult to effectively extract metal elements from the slag, so the treatment of waste slag has always been a challenge.

2、 Method for Metal Extraction from Garbage Slag

1. Acid leaching method

Acid leaching method is a commonly used method for extracting metal from waste slag. This method utilizes the corrosive effect of acid to dissolve metal elements from the slag. The operating steps of the acid leaching method are as follows:

(1) Crush garbage and slag into fine powder.

(2) Soak the fine powder in acid.

(3) Filter the soaked solution.

(4) Separate and extract the filtered solution by electrolysis or other methods.

2. Molten salt immersion method

The molten salt leaching method is a relatively new method for extracting metal from waste slag. This method utilizes the corrosive effect of high-temperature molten salt to dissolve metal elements from the slag. The operating steps of the molten salt leaching method are as follows:

(1) Crush garbage and slag into fine powder.

(2) Mix fine powder with molten salt and heat to high temperature.

(3) Separate and extract the solution at high temperature.

3. Bioleaching method

Bioleaching is an environmental protection method for metal extraction from waste slag. This method utilizes the metabolic action of microorganisms to dissolve metal elements from slag. The operation steps of Bioleaching method are as follows:

(1) Crush garbage and slag into fine powder.

(2) Mix the fine powder with microorganisms and add an appropriate amount of nutrients.

(3) Wait for a certain period of time for microbial metabolism to dissolve metal elements from the slag.

(4) Separate and extract the solution.

III. Conclusion

Metal extraction from garbage slag is a very important work, which can not only solve the problem of garbage slag treatment, but also recover the metal elements in garbage, playing a role in Recycling. At present, acid leaching, molten salt leaching and Bioleaching are commonly used methods to extract metals from waste slag. However, these methods all have certain limitations and need to be improved and perfected in practical applications. It is believed that with the continuous progress of science and technology, the technology of garbage slag metal extraction will become more and more mature, making greater contributions to environmental protection and Recycling.