阅读说明：本技术 一种基于二氧化碳的铜火法精炼工艺 (Copper fire refining process based on carbon dioxide ) 是由 王庆轮 高大银 王浩 于 2021-06-17 设计创作，主要内容包括：本发明公开了一种基于二氧化碳的铜火法精炼工艺,包括如下步骤：(1)将铜原料加入精炼炉中加热熔化,同时向铜原料中通入第一气体并不断搅拌,得到熔化的铜液；(2)向铜液中加入溶剂,随后持续向铜液中通入第二气体进行氧化,氧化结束,静置、扒渣；(3)持续将还原剂加入扒渣后的铜液中进行还原,还原结束后将铜液冶炼成型即得到所需的精铜。本发明的铜火法精炼工艺,通过氧气和二氧化碳的混合输入,一方面,输入的氧气流量可调,避免了铜液的过度氧化；另一方面,利用二氧化碳作为熔料搅拌和输送的工艺介质,不仅避免了铜液在还原过程中的边还原边氧化的问题,而且降低了氮氧化物的超标排放风险。(The invention discloses a copper fire refining process based on carbon dioxide, which comprises the following steps: (1) adding a copper raw material into a refining furnace for heating and melting, and introducing a first gas into the copper raw material while continuously stirring to obtain molten copper; (2) adding a solvent into the copper liquid, then continuously introducing a second gas into the copper liquid for oxidation, standing and slagging off after the oxidation is finished; (3) and continuously adding a reducing agent into the copper liquid after slagging off for reduction, and smelting and forming the copper liquid after reduction to obtain the required refined copper. According to the copper fire refining process, the mixed input of oxygen and carbon dioxide is adopted, so that on one hand, the flow of the input oxygen is adjustable, and the excessive oxidation of copper liquid is avoided; on the other hand, carbon dioxide is used as a process medium for stirring and conveying the molten material, so that the problem that the copper liquid is reduced and oxidized during the reduction process is avoided, and the excessive emission risk of nitrogen oxides is reduced.)

1. A copper fire refining process based on carbon dioxide is characterized in that: the method comprises the following steps:

(1) adding a copper raw material into a refining furnace for heating and melting, and simultaneously introducing a first gas into the copper raw material and continuously stirring to obtain molten copper liquid, wherein the first gas is a mixed gas of oxygen and carbon dioxide, the input flow of the carbon dioxide is 600-1200 Nm/h, and the input flow of the oxygen accounts for 0-25% of the total input flow of the first gas;

(2) adding a solvent into the copper liquid, continuously introducing a second gas into the copper liquid for oxidation, standing and slagging off after the oxidation is finished, wherein the second gas comprises oxygen and carbon dioxide, the input flow of the carbon dioxide is 600-1200 Nm/h, and the input flow of the oxygen accounts for 0-25% of the total input flow of the second gas;

(3) and continuously adding a reducing agent into the copper liquid after slagging off for reduction, and smelting and forming the copper liquid after reduction to obtain the required refined copper.

2. The carbon dioxide based copper fire refining process according to claim 1, characterized in that: in the step (1), the copper raw material is added into the refining furnace in batches, the refining furnace is continuously preheated to 1150 ℃ during the adding of the copper raw material, and the refining furnace is continuously heated to 1250 ℃ or above after the adding is finished.

3. The carbon dioxide based copper fire refining process according to claim 1, characterized in that: and in the second gas, the input flow rate of the carbon dioxide is 600-800 Nm/h, and the input flow rate of the oxygen accounts for 10% -25% of the total input flow rate of the second gas.

4. The carbon dioxide based copper fire refining process according to claim 1, characterized in that: in the step (2), when the oxygen content in the copper liquid reaches 0.4-0.6%, the oxidation is finished.

5. The carbon dioxide based copper fire refining process according to claim 1, characterized in that: in the step (3), the reducing agent is mixed into a third gas, and then the third gas mixed with the reducing agent is continuously introduced into the molten copper.

6. The carbon dioxide based copper fire refining process according to claim 5, characterized in that: the third gas is carbon dioxide, and the input flow rate of the third gas is 300-600 Nm/h.

7. The carbon dioxide based copper fire refining process according to claim 5, characterized in that: first gas the second is gaseous with the third is gaseous respectively through mixing gas equipment and mixing and sending into in the refining furnace, mix gas equipment include with the refining furnace is linked together mix the gas pitcher, install in mix oxygen percentage table on the gas pitcher, two communicate in mix the gas pitcher on be used for respectively letting in oxygen and carbon dioxide the gas transmission pipeline, along keeping away from mix the direction of gas pitcher and locate every in proper order the gas transmission pipeline on check valve, temperature transmitter, pressure transmitter, flowmeter, flow control valve, electric switch valve, relief pressure valve and remote control module.

8. The carbon dioxide based copper fire refining process according to claim 7, characterized in that: the set parameter of the pressure reducing valve is 0.3-0.4 MPa.

9. The carbon dioxide based copper fire refining process according to claim 1, characterized in that: in the step (3), when the oxygen content in the copper liquid is reduced to 0.1-0.2%, the reduction is finished.

10. The carbon dioxide based copper fire refining process according to claim 1, characterized in that: the adding amount of the solvent accounts for 0.005-0.008% of the adding amount of the copper raw material, and the adding amount of the reducing agent accounts for 0.014-0.02% of the adding amount of the copper raw material.

Technical Field

The invention relates to a copper fire refining process based on carbon dioxide.

Background

The copper pyrometallurgy refers to the process of pyrometallurgy of producing pyrometallurgy copper by removing impurities from crude copper and regenerated copper. At present, copper fire refining mainly comprises two stages of oxidation and reduction, wherein a solvent and compressed air are added into molten copper, impurities in the copper are oxidized by oxygen in the compressed air and oxidation slag is discharged, then the compressed air is used as a carrier to send a reducing agent into the copper to reduce the oxidized copper into metal copper, and the copper is cast after the reduction is finished to obtain refined copper.

In the whole oxidation and reduction process of copper pyro-refining, compressed air is used as an important process medium and plays roles in oxidation and transportation respectively. However, compressed air is used as a process medium, firstly, because the oxygen content in the compressed air is fixed, the excessive oxidation of the molten copper is easily caused in the production process, the subsequent reduction time is increased, the refining efficiency is reduced, and the refining cost is increased; secondly, because the compressed air contains a large amount of nitrogen, the nitrogen can generate a large amount of nitrogen oxide in a high-temperature state, and the nitrogen oxide is a main smoke emission pollutant and can cause great damage to the environment due to over-standard emission; finally, because the compressed air contains oxygen, the compressed air is introduced in the reduction stage, so that the copper liquid is partially oxidized while being reduced, the reduction time is prolonged, the consumption of the reducing agent is increased, and the cost is increased.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide a copper fire refining process based on carbon dioxide.

In order to achieve the purpose, the invention adopts the technical scheme that:

a copper fire refining process based on carbon dioxide comprises the following steps:

(1) adding a copper raw material into a refining furnace for heating and melting, and simultaneously introducing a first gas into the copper raw material and continuously stirring to obtain molten copper liquid, wherein the first gas is a mixed gas of oxygen and carbon dioxide, the input flow of the carbon dioxide is 600-1200 Nm/h, and the input flow of the oxygen accounts for 0-25% of the total input flow of the first gas;

(2) adding a solvent into the copper liquid, continuously introducing a second gas into the copper liquid for oxidation, standing and slagging off after the oxidation is finished, wherein the second gas comprises oxygen and carbon dioxide, the input flow of the carbon dioxide is 600-1200 Nm/h, and the input flow of the oxygen accounts for 0-25% of the total input flow of the second gas;

(3) and continuously adding a reducing agent into the copper liquid after slagging off for reduction, and smelting and forming the copper liquid after reduction to obtain the required refined copper.

Preferably, in the step (1), the copper raw material is added into the refining furnace in batches, the refining furnace is continuously preheated to 1150 ℃ during the adding of the copper raw material, and the refining furnace is continuously heated to 1250 ℃ or above after the adding is finished.

Preferably, the input flow rate of the carbon dioxide in the second gas is 600-800 Nm/h, and the input flow rate of the oxygen accounts for 10% -25% of the total input flow rate of the second gas.

Preferably, in the step (2), when the oxygen content in the copper liquid reaches 0.4-0.6%, the oxidation is finished.

Preferably, in the step (3), the reducing agent is mixed into a third gas, and then the third gas mixed with the reducing agent is continuously introduced into the copper liquid.

Further preferably, the third gas is carbon dioxide and the input flow rate is 300-600 Nm/h.

Further preferably, the first gas the second is gaseous with the third is gaseous respectively through mixing gas equipment and mixing and sending into in the refining furnace, mix gas equipment include with the refining furnace is linked together mix the gas pitcher, install in mix oxygen percentage table on the gas pitcher, two communicate in mix the gas pitcher be used for respectively letting in oxygen and carbon dioxide gas transmission pipeline, along keeping away from mix every in proper order in the direction of gas pitcher check valve, temperature transmitter, pressure transmitter, flowmeter, flow control valve, electric switch valve, relief pressure valve and remote control module on the gas transmission pipeline.

More preferably, the setting parameter of the pressure reducing valve is 0.3-0.4 MPa.

Preferably, in the step (3), when the oxygen content in the copper liquid is reduced to 0.1-0.2%, the reduction is finished.

Preferably, the adding amount of the solvent accounts for 0.005-0.008% of the adding amount of the copper raw material, and the adding amount of the reducing agent accounts for 0.014-0.02% of the adding amount of the copper raw material.

Due to the application of the technical scheme, compared with the prior art, the invention has the following advantages: according to the copper fire refining process, the mixed input of oxygen and carbon dioxide is adopted, so that on one hand, the flow of the input oxygen is adjustable, and the excessive oxidation of copper liquid is avoided; on the other hand, utilize carbon dioxide as the process medium of melt stirring and transport, because carbon dioxide does not participate in chemical reaction in process of production, not only avoided the problem of copper liquid reduction while oxidation in the reduction process, reduced nitrogen oxide's the discharge risk that exceeds standard moreover, the emission volume of nitrogen oxide of this application only is 50~60mg/m and educes greatly, is less than national emission standard, accords with the environmental protection requirement.

Drawings

FIG. 1 is a schematic view of a gas mixing apparatus in an embodiment of the present invention.

In the figure: 1. a gas mixing tank; 2. an oxygen percentage meter; 3. a first pipeline; 4. a second pipeline; 5. a check valve; 6. a temperature transmitter; 7. a pressure transmitter; 8. a flow meter; 9. a flow regulating valve; 10. an electrically operated on-off valve; 11. a pressure reducing valve; 12. a refining furnace.

Detailed Description

The technical scheme of the invention is further explained by combining the attached drawings.

The application relates to improvement of a copper fire refining process, and provides a carbon dioxide-based copper fire refining process, wherein oxygen and carbon dioxide are mixed and input, so that on one hand, the flow of the input oxygen is adjustable, and excessive oxidation of copper liquid is avoided; on the other hand, carbon dioxide is used as a process medium for stirring and conveying a molten material, and the carbon dioxide does not participate in chemical reaction in the production process, so that the problem that the copper liquid is reduced and oxidized in the reduction process is avoided, and the excessive emission risk of nitrogen oxides is reduced.

As shown in fig. 1, there is shown a gas mixing apparatus for mixing oxygen and carbon dioxide and feeding into a finer 12, which comprises a gas mixing tank 1 communicated with a refining furnace 12, an oxygen dial indicator 2 arranged on the gas mixing tank 1, two gas transmission pipelines respectively communicated with the gas mixing tank 1 and used for introducing oxygen and carbon dioxide, a check valve 5, a temperature transmitter 6, a pressure transmitter 7, a flowmeter 8, a flow regulating valve 9, an electric switch valve 10, a pressure reducing valve 11 and a remote control module (not shown in the figure) which are sequentially arranged on each gas transmission pipeline along the direction far away from the gas mixing tank 1, wherein the gas transmission pipelines comprise a first pipeline 3 which is arranged up and down and used for introducing carbon dioxide and a second pipeline 4 which is arranged up and down and used for introducing oxygen, an air duct (not shown) is connected to the gas mixing tank 1 for introducing the mixed gas in the gas mixing tank 1 into the refining furnace 12. The remote control module is a computer system and is used for controlling the input flow of oxygen and carbon dioxide according to parameters uploaded by elements such as the temperature transmitter 6, the pressure transmitter 7 and the flowmeter 8 and the real-time production condition. The set parameter of the pressure reducing valve 11 is 0.3-0.4 MPa, so that the copper liquid is prevented from splashing due to overhigh pressure of introduced gas.

The copper fire refining process based on carbon dioxide comprises the following steps:

(1) utilize removal fork truck formula feeder to add the copper raw materials in batch to refining furnace 12, the in-process of adding the copper raw materials lasts to refining furnace 12 preheat to 1150 ℃, with refining furnace 12 continue to heat more than 1250 ℃ after the reinforced material, let in first gas and constantly stir in the copper raw materials simultaneously, obtain the molten copper liquid, wherein, first gas is the mist of oxygen and carbon dioxide, the input flow of carbon dioxide is 600~1200Nm year/h, the input flow of oxygen accounts for 0~25% of first gas input total flow.

In the embodiment, the refining furnace 12 is continuously preheated to 1150 ℃ in the charging process, so that the heating efficiency can be greatly improved, the temperature can be quickly raised to over 1250 ℃ after the charging is finished, and the melting rate of the copper raw material is ensured; during the stirring, insert the tuber pipe in the copper liquid and evenly stir, the tuber pipe can stir the copper liquid upper strata, and inside the first gas of tuber pipe output can stir the copper liquid, both cooperations had accelerated the heat transfer, further accelerated the melting of copper raw materials. Here, in the melt process, the input flow of carbon dioxide is far greater than the input flow of oxygen, and specific flow is according to the difference of production situation and nimble the selection, stirs the melt through carbon dioxide, makes a small amount of oxidations of copper raw materials in the in-process of melt through a small amount of oxygen, improves subsequent oxidation efficiency.

(2) Adding a solvent into the copper liquid, continuously introducing a second gas into the copper liquid for oxidation, standing and slagging off after the oxidation is finished, wherein the second gas comprises oxygen and carbon dioxide, the input flow of the carbon dioxide is 600-800 Nm/h, and the input flow of the oxygen accounts for 10% -25% of the total input flow of the second gas.

In this embodiment, the solvent is quartz, and 6kg of the solvent is mixed into the copper liquid per ton of the copper raw material to participate in the oxidation reaction, so that the impurities in the copper liquid can react with the quartz under the action of oxygen to form oxidation slag, and then the oxidation slag is removed. Here, during the oxidation, inside inserting the copper liquid with the tuber pipe, in the oxidation process, the input flow of oxygen is far greater than the input flow of carbon dioxide, and specific flow is according to the difference of production situation and nimble selection, oxidizes the impurity in the copper liquid through oxygen, and a small amount of carbon dioxide can continue to stir the copper liquid at the in-process of oxidation, guarantees the oxidation effect.

And detecting the oxygen content in the copper liquid in real time, and finishing oxidation when the oxygen content in the copper liquid reaches 0.4-0.6%.

(3) And mixing a reducing agent into the third gas, then continuously introducing the third gas mixed with the reducing agent into the copper liquid subjected to slagging-off through a steel pipe coated with a refractory material for reduction, and smelting and molding the copper liquid after reduction to obtain the required refined copper. Wherein the third gas is carbon dioxide, and the input flow rate is 300-600 Nm/h.

The reducing agent can be selected from coal-based reducing agents and natural gas, and in the embodiment, the coal-based reducing agents are selected and added according to the adding amount of 14-16 kg per ton of copper raw materials. The reducing agent is conveyed by taking the carbon dioxide as a conveying carrier, so that the problems of reduction and oxidation of the copper liquid are avoided, 1 hour can be reduced during production of the furnace, and the production efficiency is improved; meanwhile, the unit consumption of the reducing agent can be reduced by 3kg, and the production cost is reduced.

And detecting the oxygen content in the copper liquid in real time, and finishing the reduction when the oxygen content in the copper liquid is reduced to 0.1-0.2%.

The above-mentioned embodiments are merely illustrative of the technical idea and features of the present invention, and the purpose thereof is to enable those skilled in the art to understand the contents of the present invention and implement the present invention, and not to limit the scope of the present invention, and all equivalent changes or modifications made according to the spirit of the present invention should be covered in the scope of the present invention.