CN116411166A - Method for flash strengthening smelting of copper-clad plate waste - Google Patents

Abstract

The invention discloses a flash enhanced smelting method of copper-clad plate waste, which comprises the steps of pretreating copper-clad plate waste by dry ice to dissociate plastics, mixing with additives and slag formers, crushing, grinding, spraying oxygen-enriched air into a high Wen Shu reaction tower space by a nozzle, rapidly completing the reaction within a few seconds to obtain a blister copper phase, a slag phase, a smoke gas phase and a smoke dust phase, controlling a certain ton of ore oxygen quantity, oxygen-enriched concentration, additive quantity and slag phase, and enabling more than 95% of noble metals in the copper-clad plate waste to be enriched in the blister copper phase and the smoke gas to be free of dioxin. The invention realizes the green low-carbon high-efficiency recovery of the electronic waste, improves the production efficiency, avoids the generation of dioxin, and has good economic and environmental benefits.

Description

A method for flash intensified smelting of copper-clad laminate waste

【Technical field】

The invention relates to a method for flash intensified smelting of copper-clad laminate waste, and belongs to the technical field of low-carbon recycling of electronic waste.

【Background technique】

Electronic waste has become a hot topic all over the world due to its large quantity, great harm and high recycling value. Copper clad laminate scrap is one of the important sources of electronic scrap.

How to avoid the generation of dioxin is very critical for electronic waste disposal. At present, there are many melting processes for processing electronic waste at home and abroad, such as Kaldor furnace, ISA furnace, Ausmelt furnace and NRT furnace, etc. These melting furnace types are all high-temperature molten pool melting furnaces. After being crushed, the electronic waste enters the high-temperature melt together with the slagging flux and air, and burns in the molten pool to remove refractory oxides such as plastic components and glass fibers, forming high-temperature flue gas, and impurity metals are oxidized to form a slag phase with the slagging flux , Copper and gold, silver, platinum, palladium and other rare and precious metals form a molten metal phase, and the metal phase and slag are incompatible with each other and are layered due to different densities. For the molten pool smelting process of electronic scrap, plastics and metal materials enter the high-temperature molten pool together, which increases the possibility of dioxin generation. Time is in the furnace body, which aggravates the occurrence of dioxin formation reaction.

On the other hand, the main chemical components of CCL scrap are copper, SiO ₂ , CaO, Al ₂ O ₃ , B ₂ O ₃ , precious metals such as Au, Ag, Pd, Pt, and plastics. Different from common copper concentrates, copper clad laminate waste has the obvious characteristics of "low iron and high boron", that is, the content of B ₂ O ₃ is high, but the content of Fe is too low, and the ratio of iron to silicon is only less than 0.1, which is difficult to meet the requirements of general smelting slag. Therefore, it is necessary to add a suitable flux to create a suitable slag type, and at the same time control the appropriate smelting conditions to enrich gold, silver, platinum, palladium and other precious metals in blister copper as much as possible, while avoiding the generation of dioxin.

【Content of invention】

In order to comprehensively recycle precious metals such as gold, silver, and platinum in copper clad laminate waste, and at the same time eliminate the environmental pollution caused by dioxins produced by plastics, a method for flash intensified smelting of copper clad laminate waste is proposed. The technical scheme adopted is:

a. Preprocessing

Put the copper-clad laminate waste into the pretreatment device, add dry ice to freeze for 5min-30min, take it out and place it at room temperature for 10min-30min, then perform physical dissociation to remove the plastic in the copper-clad laminate waste.

b. Mixing and crushing

The copper-clad laminate waste after dissociating the plastic is mixed with additives and slagging agents, crushed and ground until the particle size is less than 300 mesh, and the copper-clad laminate waste mixture is obtained.

c. Flash smelting

Spray the finely ground copper-clad laminate scrap mixture and oxygen-enriched air into a reaction tower (2) with a height of 2.0 meters to 25.0 meters and a temperature of 1000°C to 1500°C through a nozzle (1). The copper clad laminate mixture is The highly dispersed floating state falls from the upper end of the reaction tower to the lower end, and the obtained high-temperature melt falls into the bottom sedimentation tank (3). During this process, the oxygen content per ton of ore is controlled to be 150Nm ³ /t-400Nm ³ /t, the oxygen enrichment concentration is 30%-95%, the additive amount is 50kg/t-material-150kg/t-material, CaO and The mass ratio of SiO ₂ is 1.1-1.5, which can enrich more than 95% of precious metals in copper clad laminate scraps in blister copper.

d. After the high-temperature melt is stratified in the sedimentation tank (3), the blister copper and slag rich in precious metals are obtained, which are discharged from the blister copper port (4) and the slag discharge port (5) respectively; the flue gas is discharged from the flue (6) discharge.

Further, the additive is at least one of iron powder, iron sulfide powder and pyrite.

Further, the slagging agent is at least one of quartz sand and limestone.

A method for flash enhanced smelting of copper-clad laminate waste proposed by the present invention adopts a dry ice freezing method and utilizes the characteristics of different thermal expansion coefficients of metal and plastic to achieve better separation of plastic and metal in copper-clad laminate waste; The furnace nozzle sprays the mixed powder of copper-clad laminate waste and oxygen-enriched air into the space of the high-temperature reaction tower at the same time, so that the material is in a highly dispersed floating state, and the material is in full contact with the gas. The reaction takes place, and the entire reaction time is only a few seconds to more than ten seconds, which greatly reduces the harm of dioxins caused by insufficient combustion of plastics and staying in the furnace for a long time; in addition, by adding additives such as iron powder, additional Precise control of process parameters such as oxygen content per ton of ore, oxygen enrichment concentration, additive amount and slag type can make more than 95% of precious metals in copper clad laminate waste be enriched in blister copper phase. The invention realizes green, low-carbon and high-efficiency recycling of electronic waste, improves production efficiency and avoids the generation of dioxin, has good economic and environmental benefits, and has good popularization and application value.

【Description of drawings】

Fig. 1: schematic diagram of process flow diagram of the present invention.

Figure 2: Schematic diagram of the flash smelting equipment used in the present invention.

In Fig. 2, 1. Nozzle, 2. Reaction tower, 3. Sedimentation tank, 4. Crude copper port, 5. Slag discharge port, 6. Flue.

【Detailed ways】

The present invention will be further described below in conjunction with the examples, and the following examples are intended to illustrate the present invention rather than further limit the present invention.

The chemical composition of the copper-clad laminate scrap described in the following examples is shown in Table 1.

Table 1 Chemical Composition of Copper Clad Laminate Scrap

The chemical composition of the organic matter is shown in Table 2.

Table 2 Chemical composition of organic matter in copper clad laminate waste

Example 1:

Put the copper clad laminate waste into the pretreatment device, add dry ice to freeze for 5 minutes, take it out and place it at room temperature for 10 minutes, and then perform physical dissociation to remove the plastic in the copper clad laminate waste; the copper clad laminate waste after the dissociated plastic is mixed with iron powder, quartz After the sand is mixed, it is crushed and ground to a particle size of 320 meshes to obtain a copper-clad laminate waste mixture; the ground copper-clad laminate waste mixture and oxygen-enriched air are sprayed into a nozzle (1) with a height of 2.0 meters and a temperature of In the reaction tower (2) at 1000°C, the copper clad laminate mixture is in a highly dispersed floating state and falls from the upper end of the reaction tower to the lower end. Blister copper and slag rich in precious metals are obtained after middle stratification, which are respectively discharged from the blister copper port (4) and slag discharge port (5); the flue gas is discharged from the flue (6). In this process, the oxygen content per ton of ore is controlled to be 150Nm ³ /t, the oxygen enrichment concentration is 95%, the additive amount is 50kg/t-material, and the mass ratio of CaO to SiO ₂ in the slag is 1.1, thus enriching gold, silver, Blister of precious metals such as platinum, the recovery rates of copper, gold, silver and platinum are 82.91%, 98.42%, 95.43% and 96.91% respectively.

Example 2:

Put the copper-clad laminate waste into the pretreatment device, add dry ice to freeze for 15 minutes, take it out and place it at room temperature for 20 minutes, and then perform physical dissociation to remove the plastic in the copper-clad laminate waste; After the quartz sand is mixed, it is crushed and ground to a particle size of 400 meshes to obtain a copper-clad laminate waste mixture; the ground copper-clad laminate waste mixture and oxygen-enriched air are sprayed into a nozzle (1) with a height of 2.0 meters and a temperature of It is a reaction tower (2) at 1200°C. The copper-clad laminate mixture is in a highly dispersed floating state and falls from the upper end of the reaction tower to the lower end. The obtained high-temperature melt falls into the bottom sedimentation tank (3), and the high-temperature melt is in the sedimentation tank (3 ) after layering, the blister copper and slag rich in precious metals are obtained, which are respectively discharged from the blister copper port (4) and the slag discharge port (5); the flue gas is discharged from the flue (6). In this process, the oxygen content per ton of ore is controlled to be 230Nm ³ /t, the oxygen enrichment concentration is 50%, the additive amount is 90kg/t-material, and the mass ratio of CaO to SiO ₂ in the slag is 1.3, so that gold, silver, Blister of precious metals such as platinum, the recovery rates of copper, gold, silver and platinum are 83.32%, 98.65%, 96.21% and 97.23% respectively.

Example 3:

Put the copper-clad laminate waste into the pretreatment device, add dry ice to freeze for 30 minutes, take it out and place it at room temperature for 30 minutes, and then perform physical dissociation to remove the plastic in the copper-clad laminate waste; the copper-clad laminate waste after the dissociated plastic is mixed with pyrite, After the limestone is mixed, it is crushed and ground to a particle size of 450 meshes to obtain a copper clad laminate waste mixture; the ground copper clad laminate waste mixture is sprayed together with oxygen-enriched air into a nozzle (1) with a height of 25.0 meters and a temperature of In the reaction tower (2) at 1500°C, the copper clad laminate mixture is in a highly dispersed floating state and falls from the upper end of the reaction tower to the lower end. Blister copper and slag rich in precious metals are obtained after middle stratification, which are respectively discharged from the blister copper port (4) and slag discharge port (5); the flue gas is discharged from the flue (6). In this process, the oxygen content per ton of ore is controlled to be 400Nm ³ /t, the oxygen enrichment concentration is 30%, the additive amount is 150kg/t-material, and the mass ratio of CaO to SiO ₂ in the slag is 1.5, so as to enrich gold, silver, Blister of precious metals such as platinum, the recovery rates of copper, gold, silver and platinum are 85.18%, 97.24%, 97.34% and 97.87% respectively.

Example 4:

Put the copper clad laminate waste into the pretreatment device, add dry ice to freeze for 25 minutes, take it out and place it at room temperature for 10 minutes, and perform physical dissociation to remove the plastic in the copper clad laminate waste; the copper clad laminate waste after the dissociated plastic is mixed with iron powder and limestone After mixing, crush and grind to a particle size of 400 meshes to obtain the copper clad laminate waste mixture; spray the ground copper clad laminate waste mixture together with oxygen-enriched air into a nozzle (1) with a height of 8.0 meters and a temperature of 1150 The reaction tower (2) at ℃, the copper clad laminate mixture is in a highly dispersed floating state and falls from the upper end of the reaction tower to the lower end, and the obtained high-temperature melt falls into the bottom sedimentation tank (3), and the high-temperature melt is in the sedimentation tank (3) After stratification, blister copper and slag rich in precious metals are obtained, which are respectively discharged from the blister copper port (4) and the slag discharge port (5); the flue gas is discharged from the flue (6). In this process, the oxygen content per ton of ore is controlled to be 200Nm ³ /t, the oxygen enrichment concentration is 50%, the additive amount is 70kg/t-material, and the mass ratio of CaO to SiO ₂ in the slag is 1.25, thus enriching gold, silver, Blister of precious metals such as platinum, the recovery rates of copper, gold, silver and platinum are 86.43%, 97.61%, 98.14% and 98.54% respectively.

Claims (4)

1. A method for flash intensified smelting of copper-clad laminate waste, characterized in that it comprises the following steps: a. Preprocessing Put the copper-clad laminate waste into the pretreatment device, add dry ice to freeze for 5min-30min, take it out and place it at room temperature for 10min-30min, then perform physical dissociation to remove the plastic in the copper-clad laminate waste. b. Mixed crushing The copper-clad laminate waste after dissociating the plastic is mixed with additives and slagging agents, crushed and ground until the particle size is less than 300 mesh, and the copper-clad laminate waste mixture is obtained. c. Flash smelting Spray the finely ground copper clad laminate waste mixture and oxygen-enriched air into a reaction tower (2) with a height of 2.0m-25.0m and a temperature of 1000°C-1500°C through the nozzle (1). The copper clad laminate mixture is The highly dispersed floating state falls from the upper end of the reaction tower to the lower end, and the obtained high-temperature melt falls into the bottom sedimentation tank (3). During this process, the oxygen content per ton of ore is controlled to be 150Nm ³ /t-400 Nm ³ /t, the oxygen enrichment concentration is 30%-95%, and the additive amount is 50 kg/t-material-150 kg/t-material, slag The mass ratio of CaO to SiO ₂ in the medium is 1.1-1.5, which can enrich more than 95% of precious metals in copper clad laminate scraps in blister copper. d. After the high-temperature melt is stratified in the sedimentation tank (3), blister copper and slag rich in precious metals are obtained, which are discharged from the blister copper port (4) and slag discharge port (5) respectively; the flue gas is discharged from the flue (6) discharge. 2. A method for flash intensified smelting of copper-clad laminate waste according to claim 1, wherein the additive is at least one of iron powder, iron sulfide powder, and pyrite. 3 . The method for flash intensified smelting of copper clad laminate waste according to claim 1 , wherein the slagging agent is at least one of quartz sand and limestone. 4 . 4. A method for flash intensified smelting of copper-clad laminate waste according to claim 1, characterized in that the method can be used for green and low-carbon short-process recycling of electronic waste and copper-containing materials.

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