CN103964709A - Aluminum dust collection ash and aluminum metal smelting slag reuse method - Google Patents

Abstract

A method for recycling aluminum dust ash and aluminum metal smelting slag, wherein the aluminum smelting slag is processed into slag particles, the particle size of the slag particles is greater than 200 mesh and less than 400 mesh, the slag particles that meet the conditions are mixed with a binder aqueous solution to form a blank, and then the blank is pressurized and shaped to form a refractory rough blank, and then the refractory rough blank is sintered at a working temperature of 1050°C to 1450°C, and cooled to form a refractory material. In this way, the particle size of the slag particles can be controlled, and the nitrogen content of the slag particles can be effectively reduced. When the slag particles are mixed with the binder aqueous solution, the phenomenon of ammonia gas escaping due to the reaction of water and aluminum nitride can be effectively reduced, so as to reduce the cracking or bursting of the refractory rough blank or the refractory material, thereby achieving the effect of low production cost and good surface fineness of the refractory material.

Description

Aluminum dust collection ash and aluminum metal smelting slag reuse method

technical field

The invention relates to a method for recycling aluminum dust collection ash and aluminum metal smelting slag, in particular to a method that can control the particle size of slag particles to effectively reduce the nitrogen content of slag particles, and when the slag particles are mixed with an aqueous binder solution Finally, it can effectively reduce the phenomenon of ammonia gas escaping due to the reaction between water and aluminum nitride, so as to reduce the cracking or bursting of rough refractory material or refractory material, and achieve the effect of low production cost and good surface fineness of refractory material .

Background technique

The smelting process of aluminum will produce slag, which contains aluminum oxides and nitrides, among which the nitrides will react with moisture in the humid air or rainwater to form ammonia gas, so the untreated slag is harmful to the environment. a certain degree of influence.

China Taiwan Invention Patent No. 583155 discloses a method for resource utilization of aluminum slag ash, which is mainly to calcine the remaining aluminum slag ash waste after the aluminum smelting slag is sorted and recycled to make the raw material of refractory materials. In order to achieve the purpose of recycling aluminum slag ash and create higher economic value; the method is to use high-temperature kiln to calcinate aluminum slag ash into a material whose main component is alumina (the mineral crystal phase is corundum) as a refractory material Raw materials can not only effectively solve the problem of aluminum slag ash waste disposal, but also save energy in the production of refractory materials and avoid waste of resources.

The above-mentioned Taiwan Invention Patent No. 583155, although aluminum slag ash can be processed into raw materials for refractory bricks, refractory mud, and castables, how to make refractory bricks and how to ensure the product yield in the process of making refractory bricks is completely ignored. expose.

In addition, in the journal "Mine and Metallurgy" published in March 100 of the Republic of China, starting from page 51, it published "Research on the Production of Refractory Materials Using Aluminum Smelting Slag as Raw Materials", which revealed that the production method of refractory materials was to use aluminum smelting slag (particle size Between 100-200 mesh) according to the ratio to mix with binder aqueous solution (carboxymethyl cellulose aqueous solution), and make refractory materials through uniaxial pressure (20 tons) forming and high-temperature sintering (1100-1400°C) .

However, the refractory materials (refractory bricks) were produced according to the content disclosed in the above-mentioned "Research on the Production of Refractory Materials Using Aluminum Smelting Slag as Raw Materials", but the following deficiencies were found:

1. After the aluminum smelting slag is mixed with the binder aqueous solution and pressurized to form a rough refractory material, before sintering, the rough refractory material will crack or burst due to pressure.

2. The nitrogen content of rough embryos in refractory bricks is relatively high, and when wet, pungent ammonia gas will escape due to the following chemical reactions. AlN+3H ₂ O→Al(OH) ₃ ↓+NH ₃ ↑

3. Even if the rough refractory material before sintering does not crack or burst, the refractory brick will crack or burst during high temperature sintering of the rough refractory material.

4. The surface fineness of refractory bricks is not good (rough).

To explore the reasons for the lack of the above, it is mainly due to the manufacturing method disclosed by the research, the nitride (aluminum nitride) content in the aluminum smelting slag is high (about 9506ppm), because the research cannot effectively reduce the nitrogen in the aluminum smelting slag Therefore, the ammonia gas escape phenomenon caused by the nitrogen compound in the refractory rough embryo meeting the binder aqueous solution is the main cause of cracking or bursting of the refractory rough embryo.

Therefore, how to effectively reduce the content of nitrides in aluminum smelting slag is the main key to reduce the subsequent leakage of ammonia gas and the cracking or bursting of rough refractory materials.

Contents of the invention

The invention provides a method for reusing aluminum dust collection ash and aluminum metal smelting slag, the main purpose of which is to control the particle size of slag particles to effectively reduce the nitrogen content of slag particles, and when the slag particles are mixed with a binder aqueous solution , can effectively reduce the phenomenon of ammonia gas escaping due to the reaction of water and aluminum nitride, so as to reduce the cracking or bursting of rough refractory material or refractory material, and achieve the effect of low production cost and good surface fineness of refractory material.

A method for reusing aluminum dust collection ash and aluminum metal smelting slag of the present invention comprises the following steps:

Step 1: processing aluminum smelting slag into slag particles;

Step 2: Make the particle size of the above-mentioned slag particles larger than 200 mesh and smaller than 400 mesh;

Step 3: mixing the slag particles meeting the conditions of step 2 with an aqueous binder solution to form a billet;

Step 4: pressurize and shape the blank to form a rough blank of refractory material;

Step 5: Sintering the rough refractory material blank at a working temperature of 1050° C. to 1450° C., and cooling down to form a refractory material.

In the above method, a procedure for detecting the nitrogen content of the slag particles is further carried out in step 2 to confirm that the nitrogen content of the slag particles is between 4400 ppm and 7000 ppm.

In the above method, the binder aqueous solution is a mixed solution of water and carboxymethyl cellulose, and the binder is added in an amount ranging from 3 wt% to 12 wt%.

In the above method, the pressure in step 4 is between 25 tons and 250 tons.

Compared with prior art, the beneficial effect that the present invention has is:

1. By controlling the particle size of the slag particles to make it larger than 200 mesh (mesh) and smaller than 400 mesh (mesh), the nitrogen content in the slag particles can be reduced to 4705ppm-6880ppm, effectively solving the cracking of refractory materials or popping, cracking or popping problems.

2. To control the particle size of slag particles to meet the above mesh, it can be achieved only by grinding, which is low cost and fast processing.

3. The nitrogen content in the slag particles is reduced, and the ammonia gas escape phenomenon of the rough refractory material can be effectively reduced accordingly.

4. Control the particle size of slag particles between 200 mesh and 400 mesh, and the surface fineness of refractory bricks is better.

Description of drawings

Fig. 1 is a schematic diagram of Step 1 of the present invention.

Fig. 2 is a schematic diagram of Step 2 of the present invention.

Fig. 3 is a schematic diagram of Step 3 of the present invention.

Fig. 4 is a schematic diagram of Step 4 of the present invention.

Fig. 5 is a schematic diagram of Step 5 of the present invention.

Fig. 6 is a comparison chart of detecting relative nitrogen content of aluminum smelting slag with different particle sizes.

Explanation of main component symbols

Aluminum smelting slag 1;

slag particles 1a;

400 mesh slag particles 10a;

binder2;

Blank material 3;

Refractory raw material 4;

Refractory material 5.

Detailed ways

Please refer to Figures 1 to 5, which are respectively a schematic diagram of step 1 of the present invention, a schematic diagram of step 2 of the present invention, a schematic diagram of step 3 of the present invention, a schematic diagram of step 4 of the present invention, and a schematic diagram of step 5 of the present invention. As shown in the figure, the present invention is a method for reusing aluminum dust collection ash and aluminum metal smelting slag, which at least includes the following steps:

Step 1: Grinding the aluminum smelting slag 1 into granules to form slag particles 1a.

Step 2: Screening slag particles 1a with a particle size between 200 mesh (mesh) and 400 mesh. In the embodiment of the present invention, slag particles 10a of 400 mesh are screened as raw materials for refractory bricks. For the 400 mesh slag The particles 10a are subjected to a nitrogen content detection procedure to confirm that the nitrogen content is between 4000ppm-4500ppm.

Step 3: Mix the 400-mesh slag particles 10a with the binder 2 to form a blank 3. The aqueous solution of the binder 2 is a mixed solution containing carboxymethyl cellulose. The amount of the aqueous solution of the binder 2 in this embodiment is 8 wt%.

Step 4: Apply a pressure of 25 tons to 250 tons to the above-mentioned blank 3, and shape it into a rough refractory blank 4. This process can be completed by performing a pressurization operation in a brick mold.

Step 5: Sintering the rough refractory material blank 4 at a working temperature of 1050°C to 1450°C, and cooling down to form a refractory material 5, and a preferred temperature of 1400°C is used in the sintering process.

Figure 6 consists of two GCs and three sets of detectors (gas chromatography + thermal conductivity detector) + (gas chromatography + flame ionization detector + nitrogen chemiluminescence detector) in series (GC- TCD/FID/NCD) is used to detect the relative nitrogen content of aluminum smelting slag with different particle sizes. In the experiment, 10 kg of aluminum smelting slag was placed in a closed stirring device to simulate the operating parameters of the factory, and carboxymethyl was added in proportion The cellulose CMC binder aqueous solution is stirred by controlling the speed of the stirring unit. An air pump is installed at the gas outlet of the closed stirring device to pump the gas in the reactor to a series of analysis equipment (described before) for continuous on-line analysis. It can be seen from Figure 6 that when the particle size of the aluminum smelting slag is 100-200 mesh disclosed by the known technology, its nitrogen content is 9506 ppm, but when the particle size of the aluminum smelting slag is between 200-325 mesh, its nitrogen content is The nitrogen content is significantly reduced to 4705ppm if the particle size of the aluminum smelting slag is between 325 and 400 mesh, and the nitrogen content is only 4405ppm when the particle size of the aluminum smelting slag is larger than 400 mesh. Therefore, the present invention controls the particle size of the aluminum smelting slag to be greater than 200 mesh (mesh) and less than 400 mesh (mesh). Compared with the known technology, the nitrogen content can be effectively controlled to be only 49.49% to 49.49% of the known technology. 72.37%, the effect is extremely significant.

After the aluminum smelting slag is mixed with the aqueous binder solution and pressurized to form a rough refractory material, the rough refractory material will crack or burst before sintering. High results in high ammonia gas dissipation, resulting in cracking or bursting ratios greater than 5% during pressurization; coarse refractory materials with a mesh size of 200 or more have low ammonia gas dissipation due to low nitrogen content, resulting in cracking during pressurization Or the burst rate is less than 0.5%.

The rough refractory blanks before sintering did not crack or burst, but during the high-temperature sintering process of the rough refractory blanks, the refractory bricks will crack or burst due to the escape of ammonia gas during sintering. The high nitrogen content leads to high ammonia gas emission, which causes the cracking or bursting rate to be greater than 5% during high-temperature sintering; the coarse refractory material with a mesh size of 200 or more has low ammonia gas emission due to low nitrogen content, resulting in high temperature The rate of cracking or bursting is less than 0.5%.

So that the present invention has at least the following effects:

5. By controlling the particle size of the slag particles to make it larger than 200 mesh (mesh) and smaller than 400 mesh (mesh), the nitrogen content in the slag particles can be reduced to 4705ppm-6880ppm, effectively solving the cracking of refractory materials or popping, cracking or popping problems.

6. To control the particle size of the slag particles to meet the above mesh, it can be achieved only by grinding, which is low cost and fast processing.

7. The nitrogen content in the slag particles is reduced, and the ammonia gas escape phenomenon of the rough refractory material can be effectively reduced accordingly.

8. Control the particle size of slag particles between 200 mesh and 400 mesh, and the surface fineness of refractory bricks is better.

In summary, the aluminum dust collection ash and aluminum metal smelting slag reuse method of the present invention can effectively improve the various shortcomings that have been used, can control the particle size of the slag particles, effectively reduce the nitrogen content of the slag particles, and when the slag particles After mixing the binder aqueous solution, it can effectively reduce the phenomenon of ammonia gas escaping due to the reaction between water and aluminum nitride, so as to reduce the phenomenon of rough refractory material or refractory material cracking or bursting, so as to achieve low production cost and fineness of refractory material surface Good efficacy; and then make the production of the present invention more progressive, more practical, and more in line with the needs of consumers, and indeed meet the requirements for patent application for inventions, and apply for a patent according to law.

Claims (4)

1. an aluminium dust-collector and aluminum metal smelted furnace cinder recycling method, is characterized in that comprising the following steps:

Step 1: aluminium metallurgy slag is processed as to slag granules;

Step 2: make the particle diameter of above-mentioned slag granules be greater than 200 meshes and be less than 400 meshes;

Step 3: make to meet slag granules and a cakingagent aqueous solution of step 2 condition, form a stock;

Step 4: moulding to this stock pressurization, form the thick embryo of a refractory materials;

Step 5: the thick embryo of this refractory materials is carried out to sintering under 1050 DEG C～1450 DEG C working temperatures, and form a refractory materials through cooling.

2. aluminium dust-collector as claimed in claim 1 and aluminum metal smelted furnace cinder recycling method, is characterized in that, further carries out a slag granules nitrogen content trace routine in step 2, with the nitrogen content of confirming slag granules between 4400ppm～7000ppm.

3. aluminium dust-collector as claimed in claim 1 and aluminum metal smelted furnace cinder recycling method, is characterized in that, this cakingagent aqueous solution is the mixing solutions of water and carboxymethyl cellulose, and this cakingagent addition is between 3wt%～12 wt%.

4. aluminium dust-collector as claimed in claim 1 and aluminum metal smelted furnace cinder recycling method, is characterized in that, the pressure of this step 4 is between 25 tons～250 tons.