CN108425021A - A kind of blister copper pyrogenic process continuous refining process - Google Patents

Abstract

The invention provides a continuous refining process of blister copper by fire method, which comprises: continuously adding blister copper into an oxidation zone, and melting to obtain liquid copper; introducing an oxidizing gas into the liquid copper to oxidize the copper and make the oxidized copper liquid It flows into the reduction zone for reduction reaction; the combustible gas produced in the reduction zone is burned when it flows through the oxidation zone; the reduced copper liquid flows out continuously through the copper discharge port, and the smoke generated along with the flue gas in the oxidation zone comes out of the smoke outlet. discharge. Through the simultaneous oxidation and reduction reaction process in the continuous refining furnace, the amount of flue gas is small, the operation time can be shortened, the utilization rate of equipment can be improved, and the serious pollution problem caused by the large amount of SO ₂ flue gas emission and the crude copper cladding in the traditional process can be effectively solved. Shell cold material problem. At the same time, the flue gas volume and flue gas composition are relatively stable, and the combustible flue gas produced in the reduction zone can be burned for secondary use in the oxidation zone before being discharged, so that the waste heat of the reduction flue gas can be effectively utilized, and it has the advantages of low energy consumption, environmental friendliness, and flue gas The advantages of small quantity and high production efficiency.

Description

A continuous refining process of blister copper by fire method

technical field

The invention relates to the technical field of nonferrous metal metallurgy, in particular to a continuous refining process of blister copper by fire method.

Background technique

The pyrometallurgical process of copper generally includes three steps: copper concentrate smelting, copper matte blowing and blister copper refining. The blister copper produced by copper matte converting generally contains 98.5-99.5% copper, and the remaining impurity elements include sulfur, oxygen, iron, arsenic, antimony, zinc, tin, lead, bismuth, nickel, cobalt, etc., and usually also contain selenium, tellurium , gold and silver and other rare and precious metals. Impurity elements will have adverse effects on the conductivity and mechanical properties of copper, while valuable elements such as rare metals and precious metals need to be comprehensively recycled to improve resource utilization. Copper fire refining refers to the fire method of removing impurities such as sulfur, iron, lead, zinc, nickel, arsenic, antimony, tin, iron and oxygen in mineral blister copper and recycled copper under melting high temperature conditions to produce blister copper. copper smelting process.

The pyro-refining of blister copper mainly includes two processes of oxidation and reduction. The oxidation stage is to send the oxidant into the molten blister copper at high temperature, the Cu in the melt is first oxidized to Cu ₂ O, and the Cu ₂ O reacts with other metal impurity elements to make it oxidized, and the formed metal oxide is in the copper liquid The medium solubility is very small, and the specific gravity is light, and it can quickly rise to the liquid surface to form slag and discharge it. After the oxidation is completed, the oxygen in the copper liquid will be precipitated in the form of Cu2O during solidification, and will be distributed on the grain boundaries of Cu, which will cause harm to the electrolytic refining and require reduction and deoxidation. In the reduction stage, the reducing agent is sent into the copper liquid at high temperature, and the reducing agent reacts with Cu ₂ O in the melt to deoxidize. When the oxygen content in the copper liquid drops to a certain level, casting can be carried out.

For the traditional blister copper fire refining process, the refining reverberatory furnace is generally used to process solid copper or liquid blister copper. The production process of each furnace is divided into feeding, (copper material) melting, (copper water) Oxidation, (copper water) reduction and casting (anode plate) five stages. Due to the inherent limitation of the reverberatory furnace structure, whether it is manual feeding or mechanized feeding, the feeding speed is slow, the supplementary heat in the whole process and the low thermal efficiency of the reverberatory furnace all lead to high fuel costs for the anode plate. After the completion of the five stages of the traditional reverberatory furnace, the operation of the next furnace is continued. The productivity is low and the production cost is high.

Contents of the invention

Aiming at the deficiencies in the prior art, the purpose of the present invention is to provide a continuous refining process of blister copper by fire method, which can realize continuous smelting from blister copper to anode copper, and has the advantages of low energy consumption, environmental friendliness, and small smoke volume. , High production efficiency and so on.

In order to achieve the above object, the technical scheme that the present invention takes is as follows:

A kind of blister copper pyrotechnic continuous refining process, comprises the steps:

Continuously add blister copper into the oxidation zone of the continuous refining furnace, and melt to obtain molten copper;

Pass the oxidizing gas into the copper liquid in the oxidation zone to oxidize the copper and oxidize the impurity elements to form oxidation refining slag;

Discharge the oxidation and refining slag, and make the oxidized copper liquid flow into the reduction zone;

Feed the reducing agent into the reduction zone to make the oxidized copper liquid undergo reduction reaction;

The combustible gas generated in the reduction zone is burned when it flows through the oxidation zone;

The reduced copper liquid flows out continuously through the copper outlet, and the generated flue gas is discharged from the flue outlet together with the flue gas in the oxidation zone.

Further, the temperature in the furnace is maintained at 1150-1250°C.

Further, the flow rate of the oxidizing gas fed into the oxidation zone is a supersonic jet.

Further, the oxidation gas is fed into the oxidation zone through one or more spray guns, and the flow rate of each spray gun is about 85Nm ³ /h.

Further, the oxidizing gas is compressed air or oxygen-enriched air with an oxygen concentration of 21%-50% by volume.

Further, the oxygen content of the copper liquid flowing into the reduction zone is controlled to be 0.5-1.0%.

Further, the oxygen content of the copper liquid flowing out of the reduction zone is controlled to be 0.05-0.2%.

Further, the reducing agent is one or more of natural gas, liquefied petroleum gas, ammonia, propane, pulverized coal, and heavy oil, preferably natural gas or liquefied petroleum gas.

Further, it also includes blowing nitrogen or inert gas into the copper liquid in the reduction zone.

Further, the molten copper flowing out through the copper discharge port is cast outside the furnace.

The continuous refining process of blister copper fire method provided by the present invention shortens the operation time and improves the utilization rate of equipment by simultaneously performing oxidation and reduction processes in the continuous refining furnace. Combustion and reuse can effectively reduce energy consumption, reduce flue gas emissions, and reduce pollution. It has the advantages of environmental friendliness, high automation level, and high production efficiency.

Description of drawings

Fig. 1 is the structural representation of the blister copper fire method continuous refining furnace of one embodiment of the present invention;

Fig. 2 is a flow chart of continuous refining using the blister copper fire continuous refining furnace of the present invention.

Wherein, the reference signs are explained as follows:

1: Furnace body;

101: oxidation zone;

102: Restoration area;

2: feeding port;

3: smoke outlet;

4: partition wall;

5: Put the copper port;

61: oxidation spray gun;

62: Restoration spray gun;

7: Slag outlet.

Detailed ways

The technical solutions of the present invention will be further described below according to specific embodiments. The protection scope of the present invention is not limited to the following examples, which are listed for illustrative purposes only and do not limit the present invention in any way.

Fig. 1 is a structural schematic diagram of a blister copper fire method continuous refining furnace according to an embodiment of the present invention. As shown in Fig. 1, the blister copper fire method continuous refining furnace comprises a furnace body 1, a charging port 2, a smoke outlet 3, and a copper discharge port 5 and slag outlet 7, the copper outlet 5 is preferably a siphon copper outlet. The furnace body 1 has an oxidation zone 101 and a reduction zone 102 which communicate with each other, and the oxidation and reduction processes of blister copper can be carried out simultaneously. The smoke outlet 3 is arranged on the top of the body of furnace, the charging port 2 is arranged on the sidewall of the oxidation zone 101, the copper discharge port 5 is arranged on the sidewall of the reduction zone 102, and the slag outlet 7 is arranged on the sidewall of the oxidation zone 101. An oxidation zone and a reduction zone, and one or more of them can be respectively arranged on the side walls of the oxidation zone and the reduction zone according to actual needs.

The furnace body 1 is made of refractory materials, and the furnace space is separated from the oxidation zone 101 and the reduction zone 102 by the partition wall 4, that is, the partition wall 4 is set between the feeding oxidation zone 101 and the reduction zone 102. This partition wall 4 is fixed on the both side walls of the body of heater 1, and it does not contact with the bottom wall and the top wall of the body of heater 1, that is, there is a gap between the partition wall 4 and the bottom of the body of heater 1, and the gap can be determined according to The actual production needs to set the height enough to allow the copper liquid to flow through. For example, when the volume of the partition wall is height × width × length: 1100mm × 460mm × 280mm, the gap can be set to be about height × width × length: 200mm × 400mm × 460mm. Through the setting of the above-mentioned partition walls and gaps, the blister copper hot material fluid can be continuously fed into the furnace, ensuring that the refining process is not affected by the refining section, so that the refining process can be carried out continuously, and continuous feeding of blister copper and continuous casting of anode copper can be realized. , shorten the total operating time, improve equipment utilization and production efficiency.

There is also a gap between the partition wall 4 and the top of the furnace body 1, which can form a unified gas space in the upper part of the furnace, so that the flue gas generated during the refining process can pass through and collect in the upper furnace space of the furnace body 1, and jointly Exhausted from the smoke outlet 3 on the top of the furnace body 1, so that the flue gas generated by the reaction can be combined and processed. The formed flue gas composition, flue gas volume and flue gas temperature are relatively stable. The subsequent flue gas treatment system is simple and can be recycled. waste heat. The smoke outlet 3 is preferably arranged at the top of the oxidation zone 101, more preferably at the top of the side wall of the oxidation zone 101. When the reduction reaction proceeds to a certain extent, the combustible gas generated in the reduction zone passes through the gap between the partition wall 4 and the top of the furnace. When it flows through the oxidation zone, it is burned and utilized, and the waste heat of the reduction flue gas is effectively utilized, which can greatly reduce energy consumption.

An oxidation lance 61 and a reduction lance 62 are respectively provided at the top and/or bottom of the furnace in the oxidation zone 101 and the reduction zone 102. The oxidation lance 61 and the reduction lance 62 may be water-cooled lances, and multiples may be provided respectively. Oxidation spray gun 61 sprays oxidant into oxidation zone 101, as compressed air or oxygen concentration is the oxygen-enriched air of 21%-50% volume percentage (V%) etc., controls oxidation depth by the addition amount of oxidant, promptly controls the copper liquid content Oxygen. The oxygen-enriched air jet has a high speed, which is a supersonic jet, but the stream is very small, and the flow rate of each spray gun is about 85Nm ³ /h, so it can be injected into the melt without causing large splashes. The reducing spray gun 62 sprays reducing agents into the reducing area 102, such as natural gas, liquefied petroleum gas, ammonia, propane, pulverized coal, heavy oil, etc., and the reduction depth is controlled by the amount of reducing agent added, that is, the oxygen content of the copper liquid is controlled. The oxidant and reducing agent are sprayed into the melt through the spray gun, the melt is fully stirred, the oxidation zone 101 and the reduction zone 102 respectively control the oxidative atmosphere and the reducing atmosphere, the mass transfer and heat transfer conditions are good, and the utilization rate of the oxidant and reducing agent is high. , At the same time, the process and its devices have a high level of automation, which can automatically control the injection of oxidizing agents and reducing agents. The included angle between the oxidation lance 61 and the reduction lance 62 and the horizontal plane is 90°, and they are usually not installed near the partition wall 4 to ensure the stable flow of the melt.

The side wall and/or top wall of the reduction zone 102 is provided with a copper discharge port 5, preferably a siphon copper discharge port, through which the copper liquid after continuous refining can be discharged continuously, and then the casting process is performed. Since the casting process is not carried out in the furnace, there is no casting and short-time furnace holding period, and the waste heat of the flue gas is fully utilized, and the energy consumption will be significantly reduced compared with traditional operations.

A slag outlet 7 is also provided on the side walls of the oxidation zone 101 and the reduction zone 102, and the oxidized slag generated during the oxidation process is regularly discharged from the slag outlet 7. The slag discharge port 7 is usually set close to the partition wall 4, and can discharge the slag floating on the liquid surface to avoid polluting the copper liquid. At the same time, the slag discharge port 7 can also be used as a sampling observation port, so that the operator can observe the slag in the feeding oxidation zone 101 at any time. The state of copper liquid can be monitored online or sampled for observation.

Fig. 2 is the flow chart that utilizes blister copper fire method continuous refining furnace of the present invention to carry out continuous refining, as shown in Figure 2, blister copper fire method continuous refining process comprises the following steps:

Step S101, continuously adding blister copper from the feeding port 2 into the oxidation zone 101 of the continuous refining furnace, and melting to obtain molten copper;

Step S102, injecting oxidizing gas through the oxidizing spray gun 61 to oxidize the copper liquid in the furnace and oxidize impurity elements to generate oxidized refining slag;

Step S103, discharge the oxidized refining slag, and the oxidized copper liquid flows into the reduction zone 102 through the lower gap of the partition wall 4 of the continuous refining furnace;

Step S104: Spray a reducing agent into the reduction spray gun 62, so that the oxidized copper liquid undergoes a reduction reaction;

Step S105: the combustible gas generated in the reduction zone 102 is combusted when it flows through the oxidation zone 101 through the partition wall 4 and the furnace top of the continuous refining furnace;

Step S106: The reduced copper liquid flows out through the copper outlet, and the generated flue gas is discharged from the flue outlet 3 together with the flue gas in the oxidation zone.

Since the oxidation zone 101 and the reduction zone 102 are connected to each other and in the same furnace body 1, the oxidation and reduction processes can be carried out continuously, which ensures that the continuous refining process is not affected by the working section, thereby realizing the continuous refining of blister copper.

In step S101, the temperature in the furnace is controlled at 1150-1250°C.

In step S102, the oxidizing gas injected into the oxidizing lance may be compressed air or oxygen-enriched air with an oxygen concentration of 21-50V%. Cu is first oxidized to form Cu ₂ O, and then Cu ₂ O reacts with impurity elements (such as other metal elements, etc.) to form oxidized refining slag that can be separated from copper liquid, or the impurity elements are oxidized into metal oxides and then combined with flux to form oxidation slag. Refining slag. The jet flow speed of oxygen-enriched air is supersonic jet flow, and the flow rate of each spray gun is about 85Nm ³ /h. Because of its high jet flow speed, but the stream is small, it can be injected into the melt without causing large splash.

In step S103, the oxidized refining slag is continuously or intermittently discharged through the slag discharge port 7, and then the oxidized copper liquid flows into the reduction zone 102 through the lower gap of the partition wall 4 of the continuous refining furnace. Before the oxidized copper liquid flows into the reduction zone 102, the oxygen content in the oxidized copper liquid is controlled to be 0.5-1.0%. The oxidation depth can be controlled by blowing compressed air or oxygen-enriched air, that is, the oxygen content of the copper liquid can be controlled. The oxygen content can be detected online at the slag discharge port 7, or can be observed by sampling.

In step S104, a reducing agent is added into the copper liquid through the reducing spray gun 62, so that the oxidized copper liquid undergoes a reduction reaction. The reducing agent used is one or more of natural gas, liquefied petroleum gas, ammonia, propane, pulverized coal, and heavy oil, and the saturated Cu ₂ O in the copper liquid reacts with the reducing agent to form Cu.

In step S105, when the reducing agent such as natural gas, liquefied petroleum gas, etc., is continuously sprayed into the molten pool through the reducing spray gun 61 at high speed to carry out the reduction reaction, the combustible gas generated in the reducing zone, such as CO, burns when flowing through the oxidation zone 101, and emits The heat can be used to reduce energy consumption. In addition, a reducing agent and a gas that does not react with copper, such as nitrogen or an inert gas, can be blown into the furnace through the reducing lance 62, so as to stir the melt, improve the mass transfer and heat transfer conditions, and strengthen the smelting reaction intensity.

In step S106, the reduced copper liquid continuously flows out through the copper outlet of the reduction zone 102, and before the copper liquid flows out, the oxygen content of the reduced copper liquid is controlled to be 0.05-0.2%. The generated flue gas is discharged from the flue outlet 3 together with the flue gas in the oxidation zone 101 . Due to the continuous oxidation and reduction reaction, the reaction is continuous and stable, the flue gas is continuous and stable, and the flue gas volume is small, which solves the problems caused by the fluctuating flue gas volume of traditional refining furnaces and the different phases of flue gas components.

To sum up, the blister copper fire continuous refining process of the present invention can realize continuous smelting from blister copper to anode copper, the oxidation and reduction reaction processes are carried out simultaneously during operation, the amount of flue gas is small, the operation time can be shortened, and the utilization of equipment can be improved. The efficiency can effectively solve the serious pollution problem caused by the large amount of SO ₂ flue gas emission and the problem of the cold material of the crude copper cladding in the traditional process. At the same time, the flue gas volume and flue gas composition are relatively stable, and the combustible flue gas produced in the reduction zone can be burned for secondary use in the oxidation zone before being discharged, so that the waste heat of the reduction flue gas can be effectively utilized, and there is no casting and short time-space furnace holding period. Energy consumption will be significantly lower than traditional operations. In a word, the continuous refining furnace of the blister copper fire method of the present invention has the advantages of low energy consumption, environmental friendliness, high automation level, high production efficiency and the like.

It should be noted by those skilled in the art that the described embodiments of the present invention are only exemplary, and various other substitutions, changes and improvements can be made within the scope of the present invention. Accordingly, the present invention is not limited to the above-described embodiments, but only by the claims.

Claims (10)

1. a blister copper pyrotechnic continuous refining process, is characterized in that, comprises the steps: Continuously add blister copper into the oxidation zone of the continuous refining furnace, and melt to obtain molten copper; Pass the oxidizing gas into the copper liquid in the oxidation zone to oxidize the copper and oxidize the impurity elements to form oxidation refining slag; Discharge the oxidation and refining slag, and make the oxidized copper liquid flow into the reduction zone; Feed the reducing agent into the reduction zone to make the oxidized copper liquid undergo reduction reaction; The combustible gas generated in the reduction zone is burned when it flows through the oxidation zone; The reduced copper liquid flows out continuously through the copper outlet, and the generated flue gas is discharged from the flue outlet together with the flue gas in the oxidation zone. 2. The continuous refining process for blister copper according to claim 1, characterized in that the temperature in the furnace is maintained at 1150-1250°C. 3. The continuous refining process for blister copper according to claim 1, characterized in that the flow velocity of the oxidizing gas introduced into the oxidation zone is a supersonic jet. 4. The blister copper fire continuous refining process as claimed in claim 1, characterized in that the oxidizing gas is fed into the oxidation zone through one or more spray guns, and the flow rate of each spray gun is about 85Nm ³ /h. 5. The continuous refining process for blister copper according to claim 1, wherein the oxidizing gas is compressed air or oxygen-enriched air with an oxygen concentration of 21%-50% by volume. 6. The continuous refining process of blister copper according to claim 1, characterized in that the oxygen content of the molten copper flowing into the reduction zone is controlled to be 0.5-1.0%. 7. The continuous refining process of blister copper according to claim 1, characterized in that the oxygen content of the molten copper flowing out of the reduction zone is controlled to be 0.05-0.2%. 8. The blister copper fire continuous refining process as claimed in claim 1, wherein the reducing agent is one or more of natural gas, liquefied petroleum gas, ammonia, propane, pulverized coal, and heavy oil, preferably Natural gas or LPG. 9. The continuous refining process of blister copper according to claim 1, further comprising blowing nitrogen or an inert gas into the copper liquid in the reduction zone. 10. The continuous refining process of blister copper fire method as claimed in claim 1, characterized in that, the molten copper flowing out through the copper discharge port is cast outside the furnace.