Tin smelting method based on metallurgical waste residue recycling

Abstract

The tin smelting method comprises the following steps that (1) tin-containing waste residues and a solvent are crushed and then mixed, the mixture is placed in a smelting furnace, gas is introduced into the smelting furnace for oxygen-enriched smelting, smelting flue gas is generated, the solvent is a mixture of limestone and fluorite, the temperature of the smelting furnace is 1200-1300 DEG C, and the oxygen content in the gas is larger than or equal to 50%; (2) a reducing agent is added into a solution obtained through smelting to be mixed for reduction smelting, the reducing agent is coke or charcoal or pulverized coal, and the reduction smelting temperature is 1100-1300 DEG C; (3) adding a vulcanizing agent into a solution obtained by reduction smelting, and mixing for vulcanization volatilization; and 4) recovering tin from vulcanized and volatilized gas through condensation, electric furnace smelting or an absorption tower. The method can improve the tin extraction rate and is low in energy consumption.

Description

Technical Field

[0001] The invention relates to the technical field of smelting, and in particular to a tin smelting method based on recycling of metallurgical waste slag. Background Art

[0002] Tin has good plasticity, corrosion resistance and conductivity, and is widely used in electronics, information, electrical appliances, chemicals, metallurgy, building materials, machinery, food packaging and other industries. The waste residue produced by smelting usually contains tin, and direct disposal will cause great waste. Extracting tin from the waste residue is an effective way to recover tin. The current tin extraction method has a low extraction rate and high energy consumption, so it is necessary to improve it. Summary of the invention

[0003] In view of the problems existing in the prior art, the present invention provides a tin smelting method based on the recycling of metallurgical waste slag which can improve the tin extraction rate and has low energy consumption.

[0004] The technical solution adopted by the present invention is: a tin smelting method based on the recycling of metallurgical waste slag, comprising the following steps:

[0005] 1) crushing the tin-containing waste slag and the solvent, mixing them, placing them in a smelting furnace and introducing gas for oxygen-enriched smelting to generate smelting fume, the solvent is a mixture of limestone and fluorite, the smelting furnace temperature is 1200-1300°C, and the oxygen content in the gas is ≥50%;

[0006] 2) Adding a reducing agent to the melt obtained by the above smelting and mixing for reduction smelting, the reducing agent is coke, charcoal or coal powder, and the reduction smelting temperature is 1100-1300°C;

[0007] 3) adding a sulfiding agent to the solution obtained by the reduction smelting to mix and volatilize;

[0008] 4) The sulfide volatilized gas is recovered by condensation, electric furnace smelting or absorption tower.

[0009] As a preferred embodiment of the present technical solution, the particle size of the tin-containing waste slag and the solvent after crushing is 1-3 cm.

[0010] As a preferred embodiment of the present technical solution, the mass of the flux is 10-15% of the mass of the tin-containing waste slag.

[0011] As a preferred embodiment of the present technical solution, the mass ratio of the limestone to the fluorite is (5-3):(2-1).

[0012] As a preferred embodiment of the present technical solution, the smelting fume is filtered and then reacted with oxygen and sodium hydroxide to generate sodium sulfate, which is added to the sulfurization step.

[0013] As a preferred embodiment of the present technical solution, the vulcanization temperature is 1000-1300°C.

[0014] As a preferred embodiment of the present technical solution, the vulcanizing agent is at least one of pyrite, pyrite and tin pyrite, and gypsum is added to the vulcanizing agent as an auxiliary vulcanizing agent.

[0015] As a preferred embodiment of the present technical solution, the amount of the added reducing agent is 15-35% of the mass of the solution.

[0016] Compared with the prior art, the present invention has the following advantages:

[0017] 1. The present invention adopts oxygen-enriched smelting to increase the pressure and diffusion rate of oxygen in the furnace, increase the temperature and speed of fuel combustion, accelerate the melting of furnace charge, and improve smelting efficiency.

[0018] 2. The present invention adopts a solvent with a suitable ratio, which is beneficial to the smelting and slag-making effects and reduces the energy consumption.

[0019] 3. The reducing agent and the vulcanizing agent used in the present invention improve the effects of reduction and vulcanization and increase the extraction rate.

[0020] 4. The present invention uses the generated flue gas to prepare a substance that generates a vulcanization effect, thereby improving the vulcanization effect, effectively treating the flue gas, and reducing the energy consumption of treating the flue gas. DETAILED DESCRIPTION

[0021] The present invention is described in detail below with reference to specific embodiments.

[0022] The following examples use the same tin-containing waste slag for smelting under different conditions. The elements in the tin-containing waste slag are as follows:

[0023] Pb1.35%, Sn2.56%, FeO23.46%, Al2O33.11%, SiO25.31%, Zn2.56%, CaO7.34%, others.

[0024] Embodiment 1: A tin smelting method based on the recycling of metallurgical waste slag comprises the following steps:

[0025] 1) crushing the tin-containing waste slag and the solvent, mixing them, placing them in a smelting furnace and introducing gas for oxygen-enriched smelting to generate smelting fume, the particle size of the crushed tin-containing waste slag and the solvent is 1 cm, the solvent is a mixture of limestone and fluorite, the mass ratio of limestone to fluorite is 5:2, the mass of the flux is 15% of the mass of the tin-containing waste slag, the temperature of the smelting furnace is 1200° C., and the oxygen content in the gas is 70%;

[0026] 2) Adding a reducing agent to the melt obtained by the above smelting and mixing to carry out reduction smelting, wherein the reducing agent is coke, and the reduction smelting temperature is 1300° C. The amount of the reducing agent added is 35% of the mass of the melt.

[0027] 3) A sulfiding agent is added to the solution obtained by the above reduction smelting, and the mixture is mixed for sulfidation and volatilization. The sulfidation temperature is 1200° C. The sulfiding agent is pyrite, and the sulfiding agent accounts for 10% of the mass of the solution. Gypsum is added to the sulfiding agent as an auxiliary sulfiding agent, and the mass of gypsum is 5% of the mass of the sulfiding agent. The smelting flue gas is filtered and reacted with oxygen and sodium hydroxide to generate sodium sulfate, which is added to the sulfidation step.

[0028] 4) The volatilized gas is passed through an absorption tower to recover tin. A chemical solvent is used in the absorption tower to spray and absorb tin compounds, and then the metallic tin is reduced through a chemical reaction.

[0029] In the final slag of this embodiment, the tin content is reduced from Sn2.56% to Sn0.45%.

[0030] Embodiment 2: A tin smelting method based on the recycling of metallurgical waste slag comprises the following steps:

[0031] 1) crushing the tin-containing waste slag and the solvent, mixing them, placing them in a smelting furnace and introducing gas for oxygen-enriched smelting to generate smelting fume, the particle size of the crushed tin-containing waste slag and the solvent is 3 cm, the solvent is a mixture of limestone and fluorite, the mass ratio of limestone to fluorite is 3:1, the mass of the flux is 10% of the mass of the tin-containing waste slag, the temperature of the smelting furnace is 1300° C., and the oxygen content in the gas is 85%;

[0032] 2) Adding a reducing agent to the melt obtained by the above smelting and mixing to carry out reduction smelting, the reducing agent is coal powder, the reduction smelting temperature is 1100° C., and the amount of the reducing agent added is 15% of the mass of the melt.

[0033] 3) A sulfiding agent is added to the solution obtained by the above reduction smelting, and the mixture is mixed for sulfidation volatilization. The sulfidation temperature is 1300° C. The sulfiding agent is a mixture of pyrite and tin sulfide, and the mass ratio of the two is 3:1. Gypsum is added to the sulfiding agent as an auxiliary sulfiding agent, and the mass of the gypsum is 10% of the mass of the sulfiding agent. The smelting flue gas is filtered and reacted with oxygen and sodium hydroxide to generate sodium sulfate, and the sodium sulfate is added to the sulfidation step.

[0034] 4) The volatilized gas is smelted in an electric furnace to recover tin, and the tin-containing flue gas is introduced into the electric furnace to melt the tin again. The system is controlled to flow out and cool to obtain a tin product.

[0035] In the final slag of this embodiment, the tin content is reduced from Sn2.56% to Sn0.39%.

[0036] Embodiment 3: A tin smelting method based on the recycling of metallurgical waste slag comprises the following steps:

[0037] 1) crushing the tin-containing waste slag and the solvent, mixing them, placing them in a smelting furnace and introducing gas for oxygen-enriched smelting to generate smelting fume, the particle size of the crushed tin-containing waste slag and the solvent is 2 cm, the solvent is a mixture of limestone and fluorite, the mass ratio of limestone to fluorite is 5:1, the mass of the flux is 13% of the mass of the tin-containing waste slag, the temperature of the smelting furnace is 1250° C., and the oxygen content in the gas is 60%;

[0038] 2) Adding a reducing agent to the melt obtained by the above smelting and mixing to carry out reduction smelting, the reducing agent is charcoal, the reduction smelting temperature is 1200° C. The amount of the reducing agent added is 30% of the mass of the melt.

[0039] 3) A sulfiding agent is added to the solution obtained by the above reduction smelting, and the mixture is mixed for sulfidation and volatilization. The sulfidation temperature is 1200° C. The sulfiding agent is pyrite and tin pyrite, and the mass ratio of the two is 2:1. Gypsum is added to the sulfiding agent as an auxiliary sulfiding agent, and the mass of the gypsum is 8% of the mass of the sulfiding agent. The smelting flue gas is filtered and reacted with oxygen and sodium hydroxide to generate sodium sulfate, and the sodium sulfate is added to the sulfidation step.

[0040] 4) The volatilized gas is condensed to recover tin, and the tin-containing flue gas is condensed to condense the tin product.

[0041] In the final slag of this embodiment, the tin content is reduced from Sn2.56% to Sn1.03%.

[0042] Embodiment 4: A tin smelting method based on the recycling of metallurgical waste slag comprises the following steps:

[0043] 1) crushing the tin-containing waste slag and the solvent, mixing them, placing them in a smelting furnace and introducing gas for oxygen-enriched smelting to generate smelting fume, the particle size of the crushed tin-containing waste slag and the solvent is 3 cm, the solvent is a mixture of limestone and fluorite, the mass ratio of limestone to fluorite is 3:2, the mass of the flux is 15% of the mass of the tin-containing waste slag, the temperature of the smelting furnace is 1200° C., and the oxygen content in the gas is 75%;

[0044] 2) Adding a reducing agent to the melt obtained by the above smelting to mix and carry out reduction smelting, wherein the reducing agent is coke, and the reduction smelting temperature is 1300° C. The amount of the reducing agent added is 20% of the mass of the melt.

[0045] 3) A sulfiding agent is added to the solution obtained by the above reduction smelting, and the mixture is mixed for sulfidation volatilization. The sulfidation temperature is 1300° C. The sulfiding agent is pyrite. Gypsum is added to the sulfiding agent as an auxiliary sulfiding agent. The mass of gypsum is 10% of the mass of the sulfiding agent. The smelting flue gas is filtered and reacted with oxygen and sodium hydroxide to generate sodium sulfate, which is added to the sulfidation step.

[0046] 4) The volatilized gas passes through the absorption tower to recover tin.

[0047] In the final slag of this embodiment, the tin content is reduced from Sn2.56% to Sn0.63%.

[0048] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A tin smelting method based on the recycling of metallurgical waste slag, characterized in that: The following steps are involved: 1) crushing the tin-containing waste slag and the solvent, mixing them, placing them in a smelting furnace and introducing gas for oxygen-enriched smelting to generate smelting fume, the solvent is a mixture of limestone and fluorite, the smelting furnace temperature is 1200-1300°C, and the oxygen content in the gas is ≥50%; 2) Adding a reducing agent to the melt obtained by the above smelting and mixing for reduction smelting, the reducing agent is coke, charcoal or coal powder, and the reduction smelting temperature is 1100-1300°C; 3) adding a sulfiding agent to the solution obtained by the reduction smelting to mix and volatilize; 4) The sulfide volatilized gas is recovered by condensation, electric furnace smelting or absorption tower.

2. The tin smelting method based on the recycling of metallurgical waste slag according to claim 1, characterized in that: The particle size of the tin-containing waste slag and flux after crushing is 1-3 cm.

3. The tin smelting method based on the recycling of metallurgical waste slag according to claim 1, characterized in that: The mass of the flux is 10-15% of the mass of the tin-containing waste slag.

4. The tin smelting method based on the recycling of metallurgical waste slag according to claim 1, characterized in that: The mass ratio of the limestone to fluorite is (5-3):(2-1).

5. The tin smelting method based on the recycling of metallurgical waste slag according to claim 1, characterized in that: The smelting fume is filtered and reacted with oxygen and sodium hydroxide to generate sodium sulfate, which is added to the sulfurization step.

6. The tin smelting method based on the recycling of metallurgical waste slag according to claim 1, characterized in that: The vulcanization temperature is 1000-1300°C.

7. The tin smelting method based on the recycling of metallurgical waste slag according to claim 1, characterized in that: The vulcanizing agent is at least one of pyrite, pyrite and tin pyrite, and gypsum is added to the vulcanizing agent as an auxiliary vulcanizing agent.

8. The tin smelting method based on recycling of metallurgical waste slag according to claim 1, characterized in that: The amount of reducing agent added is 15-35% of the mass of the solution.