Method for removing phosphorus and iron from copper melt

Abstract

The invention relates to the technical field of metal material preparation, in particular to a method for removing phosphorus and iron from copper melt, which comprises the following steps: S1, melt heating: heating the copper melt to a proper temperature; s2, oxidizing to remove phosphorus and iron: fishing out the crystalline flake graphite covering the hearth of the casting furnace, exposing the copper melt in the air, and enabling phosphorus and iron in the copper melt to react with oxygen in the air to generate phosphorus oxide and iron oxide; a front hearth and a rear hearth of the casting furnace are covered with graphite flakes doped with a certain content of calcium oxide, the graphite flakes doped with a certain content of calcium oxide and covering the front hearth and the rear hearth of the casting furnace and generated slag are fished out every one hour, and then new materials are covered again. According to the method, oxidation phosphorus and iron removal, carbon-adding reduction oxygen removal and other means are adopted, phosphorus and iron in the copper melt can be effectively, conveniently and rapidly removed, the oxygen content is controlled, and the technology, equipment and raw and auxiliary materials needed by the technical scheme are mature and easy to achieve.

Description

Technical Field

[0001] The invention relates to the technical field of metal material preparation, and more specifically to a method for removing phosphorus and iron from copper melt. Background Art

[0002] Pure copper has excellent electrical conductivity, thermal conductivity, ductility, corrosion resistance, wear resistance and other excellent properties, and is widely used in electricity, electronics, energy and petrochemical, machinery and metallurgy, transportation, light industry, emerging industries and other fields. According to the different deoxidation methods, oxygen content and other impurity elements, pure copper is divided into three types, namely oxygen-free copper, red copper and phosphorus deoxidized copper.

[0003] As the electronics, automobile, and home appliance industries put forward higher requirements for the electrical conductivity, thermal conductivity, and corrosion resistance of pure copper components, more and more pure copper components tend to be made of oxygen-free copper. Therefore, many pure copper manufacturers will often switch from furnaces originally used to smelt phosphorus deoxidized copper to smelt oxygen-free copper, but this will result in excessive phosphorus content in the oxygen-free copper melt during smelting.

[0004] At this time, it becomes an urgent problem to reduce the excessive phosphorus content in oxygen-free copper melt quickly, conveniently and at low cost; In addition, when pure copper is smelted, the slag removal tool is an iron colander, and parts of the iron colander often fall off into the molten copper, causing the iron content of the molten copper to exceed the standard.

[0005] Therefore, it is a practical problem worth tackling to quickly, conveniently and at low cost reduce the excessive iron content in copper melt.

[0006] Therefore, we proposed a method for removing phosphorus and iron from copper melt to solve the above problems. Summary of the invention

[0007] In order to overcome the above-mentioned defects of the prior art, an embodiment of the present invention provides a method for removing phosphorus and iron from a copper melt to solve the problems raised in the above-mentioned background technology.

[0008] To achieve the above object, the present invention provides the following technical solution: a method for removing phosphorus and iron from a copper melt, comprising the following method: Step S1: Melt heating: raising the temperature of the copper melt to a suitable temperature; Step S2: Oxidation for phosphorus and iron removal: remove the flake graphite covering the center of the casting furnace, expose the copper melt to the air, and allow the phosphorus and iron in the copper melt to react with the oxygen in the air to generate phosphorus oxide and iron oxide; The fore chamber and the breech of the casting furnace are covered with graphite flakes doped with a certain content of calcium oxide, and the graphite flakes doped with a certain content of calcium oxide and the slag produced are removed every hour, and then covered with new ones, and at the same time, samples are taken to measure the phosphorus content until the phosphorus in the copper melt is less than 10ppm; Step S3: Melt cooling: lowering the temperature of the copper melt to a suitable temperature; Step S4: Add carbon to reduce and reduce oxygen: Cover the copper melt surface in the front chamber, middle chamber and breech of the casting furnace with charcoal, and keep the thickness of the charcoal layer at an appropriate thickness. At the same time, insert a dried and clean graphite product into the copper melt, remove the charcoal on the copper melt surface in the front chamber, middle chamber and breech every once in a while, and then quickly cover it with new charcoal until the oxygen content in the copper melt drops to within the target value.

[0009] In a preferred embodiment, the suitable temperature in step S1 is 1180°C-1200°C.

[0010] In a preferred embodiment, the graphite flakes in step S2 are graphite flakes containing 5%-15wt% calcium oxide.

[0011] In a preferred embodiment, the suitable temperature in step S3 is 1140°C-1160°C.

[0012] In a preferred embodiment, the period of time in step S4 is every 60 minutes to 90 minutes.

[0013] In a preferred embodiment, the target value of oxygen content in step S4 is 5ppm-20ppm.

[0014] In a preferred embodiment, the graphite products dried and cleaned in step S4 are graphite mold core rods and graphite mold waste.

[0015] In a preferred embodiment, in step S1, while cleaning the graphite flakes covering the center chamber of the casting furnace, the fore chamber and the breech chamber are still covered and protected by graphite flakes.

[0016] In a preferred embodiment, in step S4, the charcoal on the surface of the copper melt in the front chamber, the middle chamber and the rear chamber is removed at regular intervals, more specifically, charcoal with a thickness of 2 cm to 3 cm is left.

[0017] In a preferred embodiment, in step S4, the copper melt liquid levels in the fore chamber, middle chamber and hind chamber of the casting furnace are covered with charcoal, and the thickness of the charcoal layer is maintained at 20 cm-30 cm.

[0018] Technical effects and advantages of the present invention: 1. The present invention adopts oxidation to remove phosphorus and iron, carbon addition to reduce and remove oxygen, etc., which can effectively, conveniently and quickly remove phosphorus and iron in copper melt and control oxygen content.

[0019] 2. The process, equipment and raw and auxiliary materials required for the technical solution of the present invention are relatively mature and easy to implement. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the process of the present invention. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of 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.

[0022] Embodiment 1: Reference Figure 1 , a method for removing phosphorus and iron from copper melt, comprising the following steps: Step S1: Heating the melt: raising the temperature of the copper melt to 1200°C.

[0023] Step S2: Oxidation for phosphorus and iron removal: clean up the graphite flakes covering the center of the casting furnace (the front and rear chambers are still covered and protected by graphite flakes), and expose the copper melt to the air; cover the front and rear chambers of the casting furnace with graphite flakes doped with 5wt% calcium oxide, remove the graphite flakes doped with 5wt% calcium oxide and the generated slag covering the front and rear chambers of the casting furnace every hour, and then cover them with new ones, and take samples to measure the phosphorus content. After 5 hours, the phosphorus content in the copper melt is reduced to about 5ppm.

[0024] Step S3: Melt cooling: The temperature of the copper melt is lowered to a suitable temperature of 1150°C.

[0025] Step S4: Adding carbon to reduce and deoxidize: Cover the copper melt in the fore chamber, middle chamber and breech chamber of the casting furnace with charcoal to perform carbon reduction deoxidation and oxygen isolation. The thickness of the charcoal layer is maintained at 30 cm. At the same time, a dried and clean graphite mold core rod is inserted into the copper melt to assist in reduction and deoxidation. Remove the copper melt in the fore chamber, middle chamber and breech chamber every 75 minutes (retaining 2-3 cm thick charcoal), and then quickly cover it with new charcoal. After 16 hours, the oxygen content in the copper melt drops to about 10 ppm.

[0026] Embodiment 2: Reference Figure 1 , a method for removing phosphorus and iron from copper melt, comprising the following steps: Step S1: Heating the melt: raising the temperature of the copper melt to 1200°C.

[0027] Step S2: Oxidation for phosphorus and iron removal: clean up the graphite flakes covering the center of the casting furnace (the front and rear chambers are still covered and protected by graphite flakes), and expose the copper melt to the air; cover the front and rear chambers of the casting furnace with graphite flakes doped with 10wt% calcium oxide, remove the graphite flakes doped with 10wt% calcium oxide and the generated slag covering the front and rear chambers of the casting furnace every hour, and then cover them with new ones, and take samples to measure the phosphorus content. After 4 hours, the phosphorus content in the copper melt is reduced to about 5ppm.

[0028] Step S3: Melt cooling: The temperature of the copper melt is lowered to a suitable temperature of 1150°C.

[0029] Step S4: Adding carbon to reduce and deoxidize: Cover the copper melt in the fore chamber, middle chamber and breech chamber of the casting furnace with charcoal to perform carbon reduction deoxidation and oxygen isolation. The thickness of the charcoal layer is maintained at 30 cm. At the same time, a dried and clean graphite mold core rod is inserted into the copper melt to assist in reduction and deoxidation. Remove the copper melt in the fore chamber, middle chamber and breech chamber every 60 minutes (retaining 2-3 cm thick charcoal), and then quickly cover it with new charcoal. After 12 hours, the oxygen content in the copper melt drops to about 10 ppm.

[0030] Embodiment three: Reference Figure 1 , a method for removing phosphorus and iron from copper melt, comprising the following steps: Step S1: Heating the melt: raising the temperature of the copper melt to 1200°C.

[0031] Step S2: Oxidation for phosphorus and iron removal: clean up the graphite flakes covering the center of the casting furnace (the front and rear chambers are still covered and protected by graphite flakes), and expose the copper melt to the air; cover the front and rear chambers of the casting furnace with graphite flakes doped with 15wt% calcium oxide, remove the graphite flakes doped with 10wt% calcium oxide and the generated slag covering the front and rear chambers of the casting furnace every hour, and then cover them with new ones, and take samples to measure the phosphorus content. After 3 hours, the phosphorus content in the copper melt is reduced to about 5ppm.

[0032] Step S3: Melt cooling: The temperature of the copper melt is lowered to a suitable temperature of 1150°C.

[0033] Step S4: Adding carbon to reduce and deoxidize: Cover the copper melt in the fore chamber, middle chamber and breech chamber of the casting furnace with charcoal to perform carbon reduction deoxidation and oxygen isolation. The thickness of the charcoal layer is maintained at 30 cm. At the same time, a dried and clean graphite mold core rod is inserted into the copper melt to assist in reduction and deoxidation. Remove the copper melt in the fore chamber, middle chamber and breech chamber every 60 minutes (leaving 2-3 cm thick charcoal), and then quickly cover it with new charcoal. After 18 hours, the oxygen content in the copper melt drops to about 5 ppm.

[0034] From the above embodiments, we can see that when the calcium oxide in the graphite flakes is changed, the phosphorus content in the copper melt can be changed accordingly. More specifically, Example 1: When the fore chamber and the breech of the casting furnace are covered with graphite flakes doped with 5wt% calcium oxide, the graphite flakes doped with 5wt% calcium oxide and the slag produced on the fore chamber and the breech of the casting furnace are removed every hour; Example 2: The fore chamber and the breech of the casting furnace are covered with graphite flakes doped with 10wt% calcium oxide, and the graphite flakes doped with 10wt% calcium oxide and the slag produced on the fore chamber and the breech of the casting furnace are removed every hour; Example 3: The fore and breech of the casting furnace are covered with graphite flakes doped with 15 wt % calcium oxide, and the graphite flakes doped with 10 wt % calcium oxide covering the fore and breech of the casting furnace and the generated slag are fished out every hour.

[0035] The resulting effect is as follows: Example 1: After 5 hours, the phosphorus content in the copper melt is reduced to about 5 ppm; Example 2: After 4 hours, the phosphorus content in the copper melt is reduced to about 5 ppm; Example 3: After 3 hours, the phosphorus content in the copper melt is reduced to about 5 ppm.

[0036] From the above content, we can clearly see that when the calcium oxide content in the graphite flakes is changed, the time for the phosphorus content in the copper melt to decrease is reduced, thereby improving the processing efficiency.

[0037] By changing the frequency of scooping in step S4 and the processing time, the oxygen content in the copper solution can be reduced; The specific contents are as follows: Example 1: Every 75 minutes, the copper melt surface of the front chamber, middle chamber and breech chamber is removed (leaving 2-3 cm thick charcoal), and then quickly covered with new charcoal. After 16 hours, the oxygen content in the copper melt drops to about 10 ppm; Example 2: Every 60 minutes, the copper melt in the front chamber, middle chamber and breech chamber was removed (leaving 2-3 cm thick charcoal), and then quickly covered with new charcoal. After 12 hours, the oxygen content in the copper melt dropped to about 10 ppm; Example 3: Every 60 minutes, the copper melt surface in the front chamber, middle chamber and breech chamber was removed (leaving 2-3 cm thick charcoal), and then quickly covered with new charcoal. After 18 hours, the oxygen content in the copper melt dropped to about 5 ppm.

[0038] From the above content, we can conclude that the oxygen content in the copper melt can be reduced to about 5ppm by removing it every 60 minutes and processing it for 18 hours, which meets the processing requirements.

[0039] Finally: The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for removing phosphorus and iron from copper melt, characterized in that: The following methods are included: Step S1: Melt heating: raising the temperature of the copper melt to a suitable temperature; Step S2: Oxidation for phosphorus and iron removal: remove the flake graphite covering the center of the casting furnace, expose the copper melt to the air, and allow the phosphorus and iron in the copper melt to react with the oxygen in the air to generate phosphorus oxide and iron oxide; The fore chamber and the breech of the casting furnace are covered with graphite flakes doped with a certain content of calcium oxide, and the graphite flakes doped with a certain content of calcium oxide and the slag produced are removed every hour, and then covered with new ones, and at the same time, samples are taken to measure the phosphorus content until the phosphorus in the copper melt is less than 10ppm; Step S3: Melt cooling: lowering the temperature of the copper melt to a suitable temperature; Step S4: Add carbon to reduce and reduce oxygen: Cover the copper melt surface in the front chamber, middle chamber and breech of the casting furnace with charcoal, and keep the thickness of the charcoal layer at an appropriate thickness. At the same time, insert a dried and clean graphite product into the copper melt, remove the charcoal on the copper melt surface in the front chamber, middle chamber and breech every once in a while, and then quickly cover it with new charcoal until the oxygen content in the copper melt drops to within the target value.

2. The method for removing phosphorus and iron from a copper melt according to claim 1, characterized in that: The suitable temperature in step S1 is 1180°C-1200°C.

3. The method for removing phosphorus and iron from molten copper according to claim 1, characterized in that: The graphite flakes in step S2 are graphite flakes containing 5%-15wt% calcium oxide.

4. The method for removing phosphorus and iron from molten copper according to claim 1, characterized in that: The suitable temperature in step S3 is 1140°C-1160°C.

5. The method for removing phosphorus and iron from molten copper according to claim 1, characterized in that: The period of time in step S4 is every 60 minutes to 90 minutes.

6. The method for removing phosphorus and iron from molten copper according to claim 1, characterized in that: The target value of oxygen content in step S4 is 5ppm-20ppm.

7. The method for removing phosphorus and iron from molten copper according to claim 1, characterized in that: The graphite products dried and cleaned in step S4 are graphite mold core rods and graphite mold waste.

8. The method for removing phosphorus and iron from molten copper according to claim 1, characterized in that: In step S1, during the process of cleaning the graphite flakes covering the center chamber of the casting furnace, the fore chamber and the breech chamber are still covered and protected by graphite flakes.

9. The method for removing phosphorus and iron from molten copper according to claim 1, characterized in that: In step S4, the charcoal on the surface of the copper melt in the front chamber, the middle chamber and the rear chamber is removed at regular intervals. More specifically, charcoal with a thickness of 2 cm to 3 cm is left.

10. The method for removing phosphorus and iron from molten copper according to claim 1, characterized in that: In step S4, the copper melt liquid surfaces in the fore chamber, middle chamber and hind chamber of the casting furnace are covered with charcoal, and the thickness of the charcoal layer is maintained at 20 cm-30 cm.

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