KR890001656B1 - Producing method of al by dry reducing - Google Patents

Abstract

The production of Aluminum metal from alumina based materials by dry reduction. comprises the following processes; first, clay and kaoline are dry and broken into fragments. Sub-materials are added to the main material. The sub-materials are cryrite calcium fluoride, potassium fluoride sodium hydroxide, ammonium sulfate, ammonia water, silica, sodium nitride, potassium nitrate, chlorine, aluminum flux, carbon powder sulfur, magnesite, sodium chloride; and pelletizing material has a coating layer of carbon powder. The pellet in the furnace is blown in with air and heated, therefore melting-reduced.

Description

[Name of invention]

Method for producing aluminum by dry reduction

Detailed description of the invention

The present invention relates to a method of smelting aluminum by using kaolin and clay containing a large amount of aluminum as a raw material and using aluminum as a dry reduction method.

In general, an aluminum smelting it is common to prepare a primarily Al ₂ O ₃ in the ore to main material is aluminum wongwangseok Jewel site (Bauxite) and using the method for decomposing a second Al ₂ O ₃ electric drive. However, the present inventors have succeeded in directly producing aluminum by dry reduction method using kaolin and clay as raw materials.

Main raw materials are clay and kaolin, and clay is alumina (Al ₂ O ₃ ) component and 15-25% aluminum component is 8-12%.

[Sample 1]

(The result of analysis of Masan Ceramics Laboratory, National Industrial Testing Institute, Industrial Promotion Agency)

[Sample 2]

(The result of the analysis of Korean science and technology cloud)

Kaolin _{[Al 2 SiO 3 (OH)} 4] is a type of clay mineral _{Al 2 O 3 39.5%, SiO} 2 and usually containing ingredients of 4605% H ₂ O14.0%, kaolin example the inventors actually used Al ₂ O ₃ 30-40% was used.

Subsidiary materials such as reducing agents and fluxes include Cryolite, Calcium Fluoride, Potassium Fluoride, Sodium Hydroxide, Ammonium Sulfate, Silica, Sodium Nitrite (sodium Nitrite), Potassium Nitrate, Potassium Nitrate, Chlorine, Chlorine, Aluminum, Flux, Carbon Powder, Sulfur, Magnesite, Salt Use

The furnace and fuel can be selectively used depending on the type of furnace, such as coke, charcoal, oil and electric power.

The manufacturing process will be described in detail, and the clay and kaolin are dried and crushed into 3-8 mm.

In the blending of raw materials such as the main raw material, which is dry and pulverized, and the reducing agent solvent, as a secondary raw material to 10 kg of clay or 10 kg of the mixture of clay and kaolin in a ratio of 3: 1,

Cryolite 180-220g

Fluoride 20-30g

Potassium Fluoride 20-30g

Sodium Hydroxide 50-150g

50-100g Ammonium Sulfate

Ammonia water 150-150ml

Silica 100-300g

Sodium Nitrite 70-120g

Potassium Nitrate 50-120g

Chlorine 20-30g

Aluminum Flux 20-30g

Carbon Powder 200-500g

Sulfur 20-100g

Magnesite 20-100g

Salt (Sodium Chloride) 100-300g

After mixing the mixture into a kneader and evenly mixed, and then knead the mixed raw material so that it does not become so thick that it does not become distracted during massification.

The agglomeration method uses a spherical or molding machine of 70-100 mm to form a rectangular cube of 50 mm x 100 mm x 200 mm and drills several small holes at appropriate intervals to promote combustion.

In this way, a large amount of carbon is applied to the surface of the formed mass so as to complete the bulk raw material. The carbon powder may be blended and molded together with the raw materials. The bulk raw material is charged into a furnace and gradually blown and heated. Although it depends on the heat source or the type of furnace, as an example, when charcoal is used in a cupola type, aluminum molten metal flows by reducing melting at 900-1,800 ° C. in 20-30 minutes.

Adjust the temperature while watching the process of reduction. Note that aluminum has a rapid oxidation rate when subjected to high temperature heat. The molten aluminum thus obtained contains this substance and other impurities in the fuel, so that in order to obtain high quality aluminum, it is put back into the crucible and heated to about 700-1,000 ° C with weak ventilation, and pure aluminum and the substance are separated by specific gravity difference. . This material is removed and then wrought to obtain aluminum bars.

The recovery rate is 20-40% depending on the aluminum content in the main raw material.

The manufacturing process as described above is as follows.

As a result of analyzing the components of the aluminum produced according to the present invention is as follows.

[Sample 1]

(Analysis result of Korea Advanced Institute of Science and Technology)

[Sample 2]

The research paper of the Korea Institute of Industrial Metals Analysis is 99.72% aluminum purity.

Aluminum production by the conventional electrolytic method has a problem that the cost of manufacturing cost is not only expensive because the power cost occupies about 80% of the manufacturing cost, but the investment cost of the actual production cost is enormous, the present invention is very small equipment investment cost and simple manufacturing method Therefore, it is possible to produce inexpensively low in comparison with the conventional method in aluminum manufacturing cost, so it is expected that it will greatly contribute to the development of national industry such as saving foreign currency and energy, as well as inventory of export competitiveness of aluminum-related industries. It is an invention.

Claims (1)

Kaolin containing 30-40% of alumina (Al ₂ O ₃ ) was dried and pulverized to 3-8mm, per 10kg of it, 180-220g of cryolite, 20-30g of fluorite, 20-30g of potassium fluoride, caustic soda 50 -150g, ammonium sulfate 50-100g, ammonia water 150-250ml, silica 100-300g, sodium nitrite 70-120g, potassium nitrate 50-120g, chlorine 20-30g, aluminum solvent 20-30g, carbon powder 200-500g, sulfur 20- 100g, 20-100g of magnesite, and 100-300g of salt are added and mixed to form agglomerates, and carbon is applied to the furnace, followed by heating in a blower at 700-1,000 ° C.