Method for separating lead bullion and copper matte and producing low-arsenic copper matte in bottom blowing furnace

Abstract

The invention belongs to the technical field of nonferrous smelting, and relates to a method for separating lead bullion and copper matte and producing low-arsenic copper matte in a bottom blowing smelting furnace. The method comprises the following steps: continuously and quantitatively adding the high-arsenic copper dross into a bottom blowing smelting furnace for oxidation smelting, introducing natural gas and oxygen into a bottom oxygen lance, keeping a low-temperature oxidizing atmosphere in the furnace, and producing a three-phase melt layer of lead bullion, low-arsenic copper matte and high-lead dross; produced lead bullion is discharged through a siphon channel; and the produced low-arsenic matte is discharged through a matte opening, and high-lead slag is discharged through a slag opening. According to the method, the problems that crude lead and matte are difficult to separate and high-arsenic matte is produced in the traditional copper scum bottom blowing reduction smelting process are solved, the content of As in the produced matte is smaller than 0.5%, and high-quality crude copper can be produced through subsequent further treatment. And meanwhile, the energy consumption is low, the cost is low, large-scale production is achieved, the industrial advantage is more obvious, the comprehensive yield of copper is 99% or above, and the removal rate of arsenic in copper is 95% or above.

Description

Technical Field

[0001] The invention belongs to the technical field of nonferrous smelting, and in particular relates to a method for separating crude lead and matte in a high-arsenic copper slag bottom blowing smelting furnace and producing low-arsenic matte. Background Art

[0002] Copper slag is the product of crude lead pyrometallurgical refining. A small amount of copper is associated with lead concentrate. This copper enters crude lead during the lead smelting process. Copper slag is produced when copper is smelted and removed during crude lead refining. Smelting copper slag can not only achieve comprehensive recovery, but also improve the economic benefits of the enterprise and increase the recovery rate. The main components of copper slag are Pb and Cu, generally containing 60-70% lead, 5-20% copper, and about 5% arsenic.

[0003] The invention patent application with application publication number CN101880774A, "Process and device for producing crude lead and lead matte by bottom blowing molten pool smelting and treatment of copper slag" discloses a process for treating copper slag with a bottom blowing furnace. The process mixes copper slag, stone, quartz, coke foam, iron filings, and pyrite in a ratio of 1000:50:50:70:100:70 in a bottom blowing furnace for molten pool smelting; the heat generated by the combustion of natural gas and oxygen in the molten pool or furnace is used for heating, providing the heat required for melting and reaction in the furnace.

[0004] The Fe / SiO ratio of the slag produced by the above process is 2 The weight ratio of CaO / SiO is controlled between 0.8 and 1.2. 2 The weight ratio is controlled between 0.4 and 0.8, and the lead content is below 3%. To ensure the normal fluidity of the slag in the furnace, the smelting temperature is maintained at 1050-1200°C. However, the solubility of matte in crude lead is high under this temperature condition, and it is difficult to separate crude lead and matte in the furnace.

[0005] This process has the following disadvantages: 1. The temperature of the smelting pool is high, and more matte is dissolved in crude lead. It is difficult to separate the crude lead and matte in the furnace. They can only be separated by external cooling, and the quality of the output crude lead is poor. 2. This process is reduction smelting, the As content in matte is high, and the matte has stratification. The As content in arsenic matte is more than 15%, and the output arsenic matte is difficult to dispose of. 3. A large amount of auxiliary materials are used, and the process consumes a lot of coal and natural gas, and the production cost is relatively high. Summary of the invention

[0006] In order to overcome the problem that high-arsenic matte and high-arsenic blister copper are difficult to produce from crude lead and matte in the traditional copper slag bottom blowing reduction smelting process, the present invention provides a method for separating crude lead and matte in a high-arsenic copper slag bottom blowing smelting furnace and producing low-arsenic matte.

[0007] In order to solve the above problems, the technical solution adopted by the present invention is: The high-arsenic copper slag is continuously and quantitatively added to the bottom-blown smelting furnace for oxidation smelting; oxygen and natural gas are introduced into the oxygen lance at the bottom of the bottom-blown smelting furnace to produce a three-phase melt layer of crude lead, low-arsenic copper matte and high-lead slag. The produced crude lead is discharged through the siphon port, and the produced low-arsenic copper matte and high-lead slag are discharged through the copper matte discharge port and the slag discharge port respectively.

[0008] Among them, the main raw material processed is high-arsenic copper slag, which refers to the mixed material with a weight percentage of Pb of 40-75%, a weight percentage of Cu of 4-20%, and a weight percentage of As of 4-10%, which is mainly Pb, produced by the process of copper removal by smelting or copper removal by sulfur addition when crude lead is refined by fire method in the lead smelting process. After the high-arsenic copper slag is added to the bottom-blown smelting furnace, no auxiliary materials are added.

[0009] The pressure of oxygen and natural gas injected into the furnace by the oxygen lance at the bottom of the bottom-blown smelting furnace is 0.5-0.7MPa, and the volume ratio is natural gas: oxygen = 1:2.2-2.5. The amount of natural gas used to process 1 ton of high-arsenic copper slag is 17-30Nm 3 .

[0010] The molten pool temperature of the bottom-blowing smelting furnace is maintained at 800-850°C. The overall molten pool temperature is low, and the crude lead does not melt into the matte, thereby achieving effective separation of the crude lead and matte in the furnace.

[0011] When the crude lead layer reaches 45% to 50% of the liquid level of the bottom-blown smelting furnace, crude lead, matte and high-lead slag can be released. If the crude lead layer level is too high, the slag will be entrained with crude lead and matte and lost. If the crude lead layer level is too low, the slag and the melt layer are not well separated. The produced bottom-blown smelting furnace high-lead slag contains 40 to 45% lead and ≤1% copper. The high-lead slag has a higher lead content, a low slag melting point and good fluidity; the high-lead slag has a lower copper content and a lower copper loss.

[0012] The output matte contains 40-45% Cu and less than 0.5% arsenic, which is relatively low. No arsenic matte is produced and there is no matte stratification.

[0013] The crude lead produced contains 94-96% Pb and 0.05-0.15% Cu.

[0014] The beneficial effects of the present invention are: 1. The present invention adopts an oxidation smelting process to achieve oxidation removal of arsenic in high-arsenic copper slag, avoiding the enrichment of arsenic in copper in the traditional reduction process; the removal rate of arsenic in copper of the present invention is above 95%.

[0015] 2. The present invention adopts a low-temperature oxidation smelting process to achieve a thorough separation of lead and matte in high-arsenic copper slag, with a low impurity content in crude lead. At the same time, low-arsenic matte is produced without arsenic matte and matte stratification, thereby achieving the production of high-grade matte or crude copper and effectively realizing copper efficiency.

[0016] 3. The present invention has low energy consumption and low cost. The oxidation smelting process adopts low-temperature smelting and uses less natural gas; the entire process can be smelted without adding auxiliary materials such as coal and iron filings, and energy consumption is greatly reduced.

[0017] 4. The present invention has a large processing capacity, a high metal recovery rate, and large-scale production. The daily processing capacity is more than 240 tons of high-arsenic copper slag. Large-scale production has obvious industrial advantages. The comprehensive copper recovery rate is more than 99%, and the arsenic removal rate can reach more than 95%. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The present invention is a process flow diagram of a method for producing low-lead and low-arsenic copper matte by bottom blowing and continuous oxidation of high-arsenic copper slag. DETAILED DESCRIPTION

[0019] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution in the embodiment of the present invention will be clearly described below in conjunction with the drawings in the embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Example 1 High-arsenic copper slag is continuously fed into a bottom-blown smelting furnace at a feeding rate of 15 t / h without adding any auxiliary materials. The high-arsenic copper slag contains Pb67%, Cu12% and As6.7%.

[0021] The oxygen pressure in the inner channel of the oxygen lance at the bottom of the bottom-blowing smelting furnace is ~0.6MPa, the natural gas pressure in the outer channel is ~0.7MPa, and the natural gas flow rate is 255Nm 3 / h, oxygen flow rate is 590Nm 3 / h, the lead liquid temperature is controlled at 800-850℃, when the crude lead layer is at 400-500mm and the total molten pool liquid level is at 900-1000mm, crude lead, matte and high-lead slag can be produced.

[0022] The produced crude lead (containing 95.32% Pb and 0.11% Cu) is discharged from the cooled ingot through siphon; the produced matte (containing 43.1% Cu and 0.28% As) and high-lead slag (containing 42.6% Pb and 0.74% Cu) are discharged through the matte outlet and slag outlet respectively.

[0023] Example 2 High-arsenic copper slag is continuously fed into a bottom-blown smelting furnace at a feeding rate of 15 t / h without adding any auxiliary materials. The high-arsenic copper slag contains Pb65%, Cu11%, and As9.5%.

[0024] The oxygen pressure in the inner channel of the oxygen lance at the bottom of the bottom-blowing smelting furnace is ~0.6MPa, the natural gas pressure in the outer channel is ~0.7MPa, and the natural gas flow rate is 420Nm 3 / h, oxygen flow rate is 1000Nm 3 / h, the lead liquid temperature is 800-850℃, when the crude lead layer is 400-500mm and the total molten pool liquid level is 900-1000mm, crude lead, matte and high-lead slag are produced.

[0025] The produced crude lead (containing 94.91% Pb and 0.08% Cu) is discharged from the cooled ingot through siphon; the produced matte (containing 44.7% Cu and 0.43% As) and high-lead slag (containing 44.3% Pb and 0.9% Cu) are discharged through the matte outlet and slag outlet respectively.

[0026] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for separating crude lead and copper matte in a bottom-blown smelting furnace and producing low-arsenic copper matte, characterized in that: The high-arsenic copper slag is continuously and quantitatively added to the bottom-blown smelting furnace for oxidation smelting; oxygen and natural gas are introduced into the oxygen lance at the bottom of the bottom-blown smelting furnace to produce crude lead, low-arsenic copper matte and high-lead slag; The high-arsenic copper slag refers to a mixture containing 40-75% by weight of Pb, 4-20% by weight of Cu, and 4-10% by weight of As; The volume ratio of oxygen and natural gas injected into the furnace by the oxygen lance at the bottom of the bottom-blown smelting furnace is natural gas: oxygen = 1:2.2~2.

5. The amount of natural gas used to process 1 ton of high-arsenic copper slag is 17~30Nm 3 ; The molten pool temperature of the bottom blowing smelting furnace is maintained at 800-850°C.

2. The method according to claim 1, characterized in that: The high-arsenic copper slag refers to a mixed material produced by the process of removing copper by smelting or removing copper by adding sulfur when crude lead is refined by fire in the lead smelting process.

3. The method according to claim 1, characterized in that: The pressure of oxygen and natural gas sprayed into the furnace by the oxygen lance at the bottom of the bottom blowing smelting furnace is 0.5~0.7MPa.

4. The method according to claim 1, characterized in that: When the crude lead layer reaches 45% to 50% of the molten pool level of the bottom-blown smelting furnace, crude lead, matte and high-lead slag are released.

5. The method according to claim 1, characterized in that: The crude lead produced contains 94-96% Pb and 0.05-0.15% Cu.

6. The method according to claim 1, characterized in that: The produced matte contains 40-45% Cu and less than 0.5% arsenic.

7. The method according to claim 1, characterized in that: The high-lead slag produced contains 40-45% lead and ≤1% copper.

8. The method according to claim 1, characterized in that: The produced crude lead is discharged through the siphon port of the bottom-blown smelting furnace, and the low-arsenic matte and high-lead slag are discharged through the matte discharge port and slag discharge port respectively.

Images