System and method for recovering sulfur in copper smelting process

Patent metadata

Field	Value
Publication number	US-11286162-B2
Application number	US-201816613840-A
Country	US
Kind code	B2
Filing date	Aug 31, 2018
Priority date	Aug 3, 2018
Publication date	Mar 29, 2022
Grant date	Mar 29, 2022

Abstract

A system and method for recovering sulfur in a copper smelting process includes removing fine dust from high-concentration SO2 flue gas from a matte smelting furnace, introducing the flue gas into a fluidized bed carbothermic reduction tower to be reduced by a carbon-based reducing agent to obtain reducing gas, passing the reducing gas through a high temperature separator to separate down unsaturated powder coke contained in the reducing gas, and condensing the reducing gas to obtain sulfur. The saturated powder coke entrained in the reducing gas enters a desorption tower to desorb SO2 gas therein, and the desorbed powder coke enters a fluidized bed sulfur reduction tower to continue to participate in the reduction reaction. Part of the SO2 gas discharged from the desorption tower is discharged to the fluidized bed carbothermic reduction tower to produce sulfur, and the other part enters a desulfurization tower.

First claim

The invention claimed is:

1. A method for recovering sulfur in a copper smelting process, comprising the steps of:
1) removing dust first from high-concentration SO 2 flue gas from a matte smelting furnace in a settling chamber, mixing the flue gas after dust removal with high-concentration SO 2 flue gas from a matte converting furnace, then introducing the mixed flue gas into a conditioner, introducing the conditioned flue gas into a dust removal device to remove dust carried in the flue gas, and then introducing the flue gas into a first flue gas cooler for temperature control;
2) introducing the flue gas after temperature control in the first flue gas cooler into a fluidized bed carbothermic reduction tower for oxidation-reduction reaction with a carbon-based material, performing primary gas-solid separation on the reaction gas obtained in the fluidized bed carbothermic reduction tower through a high temperature separator, returning most of the separated carbon-based reducing agent to the reduction tower to continue to serve as a reducing medium, and discharging the other small part of the carbon-based reducing agent that loses the reducing property to the conditioner to react with oxygen in the flue gas so as to remove oxygen from the flue gas;
3) condensing the reaction gas separated by the high temperature separator in a reducing gas cooler, introducing the condensed reaction gas into a dust filter for secondary gas-solid separation to ensure the quality of sulfur recovery, condensing the filtered reaction gas in a sulfur collection device to collect sulfur and storing the sulfur in a sulfur storage tank;
4) cooling the flue gas from a pyro-refining anode furnace first by a second flue gas cooler, then mixing with the reaction gas after sulfur condensation recovery in the sulfur collection device, introducing the mixed flue gas into an active coke desulfurization tower, then removing dust in the dust removal device, and discharging the flue gas through a chimney; and
5) feeding the saturated active coke in the active coke desulfurization tower into a desorption tower, and then introducing the desorbed gas into the fluidized bed carbothermic reduction tower for oxidation-reduction reaction with the carbon-based reducing agent therein to recover sulfur.

2. The method according to claim 1 , wherein in step 1), the flue gas from the matte smelting furnace and the matte converting furnace is 1000-1400° C., with the SO 2 concentration of 5-30%; the flue gas at the outlet of the conditioner is 1000-1500° C.; and the flue gas at the outlet of the first flue gas cooler is 700-1000° C.

3. The method according to claim 1 , wherein in step 2), the temperature of reaction between the flue gas and the carbon-based reducing agent in the fluidized bed carbothermic reduction tower is 700-1000° C., the molar ratio of the carbon-based reducing agent to the SO 2 is 10-100, the gas velocity in the tower is 4-8 m/s, and the gas-solid contact time in the tower is 2-12 s.

4. The method according to claim 3 , wherein the gas-solid contact time in the tower is 3-6 s, and the molar ratio of the carbon-based reducing agent to the SO 2 is 50-100.

5. The method according to claim 1 , wherein in step 2), the carbon-based reducing agent has a particle diameter of 60 μm to 3 mm.

6. The method according to claim 5 , wherein the reaction gas obtained after reduction in the fluidized bed carbothermic reduction tower is a mixture including any of N 2 , SO 2 , COS, H 2 S, CS 2 , CO, H 2 , or CO 2 .

7. The method according to claim 5 , wherein the carbon-based reducing agent has a particle diameter of 60 μm to 1 mm.

8. The method according to claim 1 , wherein in step 3), the reaction gas separated by the high temperature separator at about 700-1000° C. is condensed in the reducing gas cooler, and the temperature of the condensed reaction gas is 300-600° C.

9. The method according to claim 8 , wherein in step 5), the desorbed gas discharged from the desorption tower is 300-600° C., and the SO 2 concentration of the desorbed gas is 10-40%.

10. The method according to claim 9 , wherein the desorbed gas is a mixture including any of N 2 , SO 2 , H 2 O, or CO 2 .

11. The method according to claim 1 , wherein in step 4), the flue gas from the pyro-refining anode furnace is about 1000-1400° C., with the SO 2 concentration of less than 5%; the flue gas from the pyro-refining anode furnace is cooled to 50-130° C. by the second flue gas cooler; and the mixed flue gas is 80-160° C.

12. A system for recovering sulfur in a copper smelting process, comprising a proportioning bin, a dryer, a matte smelting furnace, a settling chamber, an electric furnace, a matte converting furnace, a slow ash cooler, a pyro-refining anode furnace, a conditioner, a dust removal device, a first flue gas cooler, a fluidized bed carbothermic reduction tower, a feed hopper, a high temperature separator, a reducing gas cooler, a fine dust filter, a sulfur recovery device, a sulfur storage tank, a desulfurization tower, a dust collector, a chimney, a desorption tower, a nitrogen making machine, and a second flue gas cooler,
wherein the bottom of the proportioning bin is connected to the dryer, the dryer is connected to the matte smelting furnace by a conveyor belt, the lower part of the matte smelting furnace is connected to the settling chamber, and a solid outlet of the settling chamber is connected to the electric furnace, the slow ash cooler, and the matte converting furnace respectively; the matte converting furnace is connected to the slow ash cooler by a pipe and connected to the pyro-refining anode furnace by a crude copper conveyor belt, the flue gas passing through the flue gas pipe is mixed with the flue gas passing through the settling chamber and then the mixed flue gas sequentially passes through the conditioner, the first dust removal device and the first flue gas cooler; the flue gas from the first flue gas cooler and the flue gas from the desorption tower are mixed and then introduced into the fluidized bed carbothermic reduction tower, and the reaction gas from the fluidized bed carbothermic reduction tower is sequentially introduced into the high temperature separator, the reducing gas cooler, the fine dust filter, and the sulfur recovery device; the condensed sulfur in the sulfur recovery device is fed into the sulfur storage tank, the flue gas from the pyro-refining anode furnace is introduced into the second flue gas cooler, mixed with the reaction gas at the outlet of the sulfur recovery device and then introduced into the active coke desulfurization tower, dust is removed in the second dust removal device, and the flue gas is discharged through the chimney; and the saturated powder coke at the bottom of the active coke desulfurization tower is delivered to the desorption tower by the conveyor belt.

13. The system according to claim 12 , wherein a buffer tank is arranged at the bottom of the fluidized bed carbothermic reduction tower, and a fluidizing air nozzle is arranged inside the buffer tank; an ash hopper and a coke storage tank are sequentially connected below the high temperature separator; one side of the buffer tank is connected to the feed hopper, the other side is connected to the coke storage tank below the high temperature separator, and the fluidizing air nozzle is lower than feed ports on two sides of the buffer tank; and an aeration air nozzle is arranged in the coke storage tank.

14. The system according to claim 12 , wherein the desorption tower is divided into three sections from top to bottom, respectively a drying and preheating section, a desorption section and a cooling

Assignees

• Univ Shandong

Inventors

• Ma Chunyuan
• Xia Xiao
• Zhao Xiqiang
• Feng Tai
• Li Jun
• Zhang Shizhen

Classifications

• F27D17/20

  Arrangements for treatment or cleaning of waste gases · CPC title

• F27D17/30

  Arrangements for extraction or collection of waste gases; Hoods therefor · CPC title

• C01B17/0482 Primary

  with carbon or solid carbonaceous materials · CPC title

• B01D2253/102

  Carbon · CPC title

• B01D53/508

  by treating the gases with solids · CPC title