A kind of chlorinated pellets and preparation method thereof

Abstract

The invention provides a chlorinated pellet and a preparation method thereof. Through establishing an efficient chloride structure pellet, HC1 gas can be quickly generated at a chlorination temperature (about 800 DEG C) far lower than a medium temperature; residual non-involved gas in the chlorination process as well as the HCl gas for chlorinating nonferrous metals can be quickly absorbed by a chlorinated gas absorbing agent; while the enough concentration of the HCI gas in the pellet is ensured, the waste of a large amount of chlorinating agents can also be prevented. In the chlorination process at a high temperature, the HCI gas absorbed by the chlorinated gas absorbing agent can also be released to continuously chlorinate the nonferrous metals, so that the defect of insufficient chlorination atmosphere in the pellet caused by high volatilization rate of the chlorinating agents at a high temperature can be overcome. Therefore, the consumption of the chlorinating agents can be greatly reduced, and the chlorination efficiency and the chlorination rate of the nonferrous metals are improved.

Description

technical field

[0001] The invention relates to the field of steel sintering raw materials, in particular to a chlorinated pellet and a preparation method thereof. Background technique

[0002] As an important secondary resource, sulfuric acid slag not only contains rich iron, but also contains a small amount of non-ferrous metals such as copper, lead, and zinc. The iron grade of sulfuric acid slag is generally 30% to 63%, which is significantly higher than the average iron ore grade of 33% in my country. The non-ferrous metals such as copper, lead, and zinc contained in it also have considerable recovery value. According to statistics, my country discharges about 15 million tons of sulfuric acid slag every year, and the accumulated sulfuric acid slag is as high as hundreds of millions of tons. This part of sulfuric acid slag not only pollutes the environment and occupies cultivated land, but also brings harm to the human body due to the non-ferrous metals it contains. As a...

Examples

preparation example Construction

[0061] The present invention also provides a preparation method of chlorinated pellets, comprising:

[0062] In parts by weight, 0 to 8 parts of the first chlorinating agent and 0 to 8 parts of the second chlorinating agent are mixed with 100 parts of sulfuric acid slag, 0 to 3 parts of bentonite and 0 to 20 parts of chlorinated gas absorbent to obtain a first mixture and a second mixture;

[0063] Adding 1-6 parts of water and ammonium chloride to the first mixture, and performing grinding;

[0064] pelletizing the moistened mixture to obtain a core;

[0065] Coating the second mixture on the outside of the core, adding water for the second grinding, forming green balls with shells;

[0066] After the first chlorination of the green pellets, the temperature is raised, and the second chlorination is carried out to obtain chlorinated pellets.

[0067] Preferably, the first chlorinating agent and the second chlorinating agent are selected from different compounds.

[0068] P...

Embodiment 1

[0074] The iron grade of sulfuric acid slag is 63.0%, the content of Cu is 1.0%, the content of zinc is 0.3%, the content of sulfuric acid slag smaller than 0.075mm is 72.58%, and the content of smaller than 0.045mm is 56.06%. Added 4% CaCl 2 , 1.8% bentonite and 2% NH 4 The sulfuric acid slag of Cl is milled in a moistening mill for 4 minutes, and the moistening water is 15%. After moistening, prepare green balls with a diameter of 8-10mm in a disc pelletizer, and continue to wrap a layer on the outer layer of the green balls to add CaO (alkalinity 1.5) and 4% CaCl 2 The sulfuric acid slag is prepared into green pellets with a diameter of 10-12.5mm, so that the mass ratio of the inner layer to the outer layer of the pellets is 1:1. The pelletizing time is 13 minutes, and the drop strength of green pellets is 4.2 times / 0.5m. After the green pellets are dried, they are chlorinated at 460°C for 5 minutes, and the hot pellets are further chlorinated at 1050°C for 10 minutes. A...

Embodiment 2

[0076] The iron grade of the sulfuric acid slag is 61.3%, the content of Cu is 0.2%, the content of Zn is 0.2%, and the content of Pb is 1.8%. Added 4% CaCl 2 , 1.5% bentonite and 2% NH 4 After the sulfuric acid slag of Cl is mixed, it is rubbed in a moistening mill for 2 minutes, and the moisture content of the moistening is 15%. After moistening, prepare green balls with a diameter of 8-10mm in a disc pelletizer, and continue to wrap One layer added CaO (alkalinity 1.5) and 4% CaCl 2 The sulfuric acid slag is prepared into green pellets with a diameter of 10-12.5mm, so that the mass ratio of the inner layer to the outer layer of the pellets is 1:1. The pelletizing time is 13 minutes, and the drop strength of green pellets is 4.6 times / 0.5m. After the green pellets are dried, they are chlorinated at 450°C for 5 minutes, and the hot pellets are further chlorinated at 1125°C for 10 minutes. Add 4% CaCl to the sulfuric acid slag with a single 2 Compared with pellets, the rem...

technical field

[0001] The invention relates to the field of steel sintering raw materials, in particular to a chlorinated pellet and a preparation method thereof. Background technique

[0002] As an important secondary resource, sulfuric acid slag not only contains rich iron, but also contains a small amount of non-ferrous metals such as copper, lead, and zinc. The iron grade of sulfuric acid slag is generally 30% to 63%, which is significantly higher than the average iron ore grade of 33% in my country. The non-ferrous metals such as copper, lead, and zinc contained in it also have considerable recovery value. According to statistics, my country discharges about 15 million tons of sulfuric acid slag every year, and the accumulated sulfuric acid slag is as high as hundreds of millions of tons. This part of sulfuric acid slag not only pollutes the environment and occupies cultivated land, but also brings harm to the human body due to the non-ferrous metals it contains. As a...

Examples

preparation example Construction

[0061] The present invention also provides a preparation method of chlorinated pellets, comprising:

[0062] In parts by weight, 0 to 8 parts of the first chlorinating agent and 0 to 8 parts of the second chlorinating agent are mixed with 100 parts of sulfuric acid slag, 0 to 3 parts of bentonite and 0 to 20 parts of chlorinated gas absorbent to obtain a first mixture and a second mixture;

[0063] Adding 1-6 parts of water and ammonium chloride to the first mixture, and performing grinding;

[0064] pelletizing the moistened mixture to obtain a core;

[0065] Coating the second mixture on the outside of the core, adding water for the second grinding, forming green balls with shells;

[0066] After the first chlorination of the green pellets, the temperature is raised, and the second chlorination is carried out to obtain chlorinated pellets.

[0067] Preferably, the first chlorinating agent and the second chlorinating agent are selected from different compounds.

[0068] P...

Embodiment 1

[0074] The iron grade of sulfuric acid slag is 63.0%, the content of Cu is 1.0%, the content of zinc is 0.3%, the content of sulfuric acid slag smaller than 0.075mm is 72.58%, and the content of smaller than 0.045mm is 56.06%. Added 4% CaCl 2 , 1.8% bentonite and 2% NH 4 The sulfuric acid slag of Cl is milled in a moistening mill for 4 minutes, and the moistening water is 15%. After moistening, prepare green balls with a diameter of 8-10mm in a disc pelletizer, and continue to wrap a layer on the outer layer of the green balls to add CaO (alkalinity 1.5) and 4% CaCl 2 The sulfuric acid slag is prepared into green pellets with a diameter of 10-12.5mm, so that the mass ratio of the inner layer to the outer layer of the pellets is 1:1. The pelletizing time is 13 minutes, and the drop strength of green pellets is 4.2 times / 0.5m. After the green pellets are dried, they are chlorinated at 460°C for 5 minutes, and the hot pellets are further chlorinated at 1050°C for 10 minutes. A...

Embodiment 2

[0076] The iron grade of the sulfuric acid slag is 61.3%, the content of Cu is 0.2%, the content of Zn is 0.2%, and the content of Pb is 1.8%. Added 4% CaCl 2 , 1.5% bentonite and 2% NH 4 After the sulfuric acid slag of Cl is mixed, it is rubbed in a moistening mill for 2 minutes, and the moisture content of the moistening is 15%. After moistening, prepare green balls with a diameter of 8-10mm in a disc pelletizer, and continue to wrap One layer added CaO (alkalinity 1.5) and 4% CaCl 2 The sulfuric acid slag is prepared into green pellets with a diameter of 10-12.5mm, so that the mass ratio of the inner layer to the outer layer of the pellets is 1:1. The pelletizing time is 13 minutes, and the drop strength of green pellets is 4.6 times / 0.5m. After the green pellets are dried, they are chlorinated at 450°C for 5 minutes, and the hot pellets are further chlorinated at 1125°C for 10 minutes. Add 4% CaCl to the sulfuric acid slag with a single 2 Compared with pellets, the rem...

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