Method for recovering copper from waste chips

Abstract

The invention provides a method for recovering copper from waste chips, which comprises the following steps: carrying out roasting phase reconstruction on the waste chips to obtain copper-containing reconstructed slag; mixing the copper-containing reconstructed slag with the Fe < 3 + > leaching solution, and leaching to obtain a copper-containing leaching solution and leaching slag; the copper-containing leachate is electrolyzed, and copper simple substances and Fe < 2 + > electrolyte are obtained; and after electrolytic oxidation is conducted on the Fe < 2 + > electrolyte, the Fe < 2 + > electrolyte is reused for leaching of the copper-containing reconstruction slag. The method has the characteristics of short process flow, continuous operation, greenness, cleanness, simplicity in operation, low cost, high comprehensive recovery value and the like.

Description

Technical Field

[0001] The invention belongs to the technical field of metallurgy and environmental protection, and relates to a method for recovering copper from waste chips. Background Art

[0002] With the rapid development of the information field, the replacement speed of electronic equipment is accelerating, and the amount of electronic waste generated is increasing. Copper is widely used in different types of electronic equipment due to its advantages such as good ductility and conductivity. With the increasing number of discarded electronic equipment, the recycling of copper-containing secondary resources has attracted widespread attention. The Chinese government pays great attention to the recycling of discarded electronic equipment, has formulated a series of policies and subsidies, and has issued relevant laws and regulations to strengthen the recycling of electronic waste.

[0003] For the recycling and treatment of waste chips, the main recycling methods are currently divided into biological methods, pyrometallurgy and hydrometallurgy. The biological method is very environmentally friendly, but the recycling volume is small and the recycling cycle is long. Although the biological method can effectively recover copper in waste chips, it is not suitable for recycling by biological methods due to the high copper content in electronic waste. The advantages of pyrometallurgy are large processing scale, simple operation and significant recycling effect, but if it is burned in the open air or smelted, toxic gases will be produced, which will cause serious harm to human health and the environment. Hydrometallurgy is to transfer the copper in electronic waste into the solution in the form of ions by mixing the leaching agent with electronic waste, and then extract and recover it from the solution. In this process, the choice of leaching agent largely determines whether toxic substances will be produced during the leaching process. In addition, the consumption of a large amount of leaching agent will also cause new problems. Although different types of recycling processes have their own advantages and disadvantages, in the wet recycling process, the production of toxic substances can be effectively avoided by the reasonable selection of leaching agents. Therefore, when treating waste chips by hydrometallurgy, it is particularly important to choose a green and efficient leaching agent.

[0004] CN115029553A discloses a method for co-processing copper-containing electronic waste by oxygen-enriched bottom blowing smelting, wherein the copper-containing waste is mixed with a flux under oxygen-enriched conditions and smelted at high temperature to obtain copper-rich waste, followed by electrolytic refining to obtain cathode copper and slag rich in precious metals. Although this method achieves copper recovery, the waste gas treatment process generated by high-temperature smelting is complicated and difficult to completely remove.

[0005] CN113528839B discloses a method for leaching aluminum with hydrochloric acid and recovering tin, copper and lead from copper-containing waste by controlled potential oxidation leaching and electrodeposition. Although this method realizes the comprehensive recovery of multiple metal elements, flammable and explosive hydrogen will be generated during the hydrochloric acid leaching process and chlorine will be generated during the controlled potential oxidation leaching process, which are very harmful to the environment.

[0006] CN113528837B discloses a method of selectively leaching iron and aluminum from copper-containing waste using sulfuric acid, and recovering copper, tin and lead from the leached slag by pyrometallurgical copper smelting and controlled potential oxidation leaching. However, the recovery process is complicated and energy-intensive, which is not conducive to large-scale industrial application.

[0007] CN111139360A discloses a method for leaching silver and copper from IC chips and components in waste mobile phone circuit boards using a mixed solution of sulfuric acid and sodium nitrate, but the leaching process will produce nitrogen oxide gas that is harmful to the environment and human body.

[0008] Since the waste chips may produce toxic substances in the traditional recycling process due to the complexity of the components in the electronic waste, it is particularly important to provide a recycling method that does not produce harmful substances in the copper recycling process. Summary of the invention

[0009] In order to solve the technical problems existing in the prior art, the present invention provides a method for recovering copper from waste chips. The method has the characteristics of short process flow, continuous operation, green cleaning, simple operation, low cost and high comprehensive recovery value. The copper leaching rate is as high as 99%, the enrichment multiple of precious metals in the enriched slag is as high as 3.5 times, the recovered copper purity is as high as 99.78%, the cathode efficiency and the anode efficiency are 97.69% and 97.78% respectively, and the copper recovery rate is as high as 99.89%.

[0010] In order to achieve the above technical effects, the present invention adopts the following technical solutions:

[0011] The present invention provides a method for recovering copper from waste chips, the method comprising the following steps:

[0012] (1) calcining waste chips to reconstruct the phase and obtain copper-containing reconstructed slag, wherein the waste chips have a copper content of 10 to 60 wt%, a silicon content of 5 to 50 wt%, and a precious metal content of 0.01 to 0.1%;

[0013] (2) The copper-containing reconstructed slag and Fe 3+ The leaching solutions are mixed and leached to obtain copper-containing leaching solution and leaching residue;

[0014] (3) Using the copper-containing leaching solution obtained in step (2) as the cathode liquid for diaphragm electrolysis to recover copper, the anode liquid is Fe 2+ Solution, Fe 2+ The concentration is 0.1~5mol / L; the cathode chamber obtains metallic copper and Fe 2+ solution, Fe in the anode compartment 2+ The solution is oxidized to form Fe 3+ leachate.

[0015] (4) Fe remaining in the cathode chamber after copper electrolysis recovery is completed 2+ The solution is used as the anode liquid to be electrolyzed and finally enters the anode chamber for electrolytic oxidation. The Fe 3+ The leaching solution is recycled and used for leaching the copper-containing reconstituted slag.

[0016] As a preferred technical solution of the present invention, the calcination temperature in step (1) is 100 to 1000° C., and the calcination time is 20 to 200 min.

[0017] As a preferred technical solution of the present invention, the Fe 3+ The concentration of the leaching solution is 0.1-5 mol / L, and the copper-containing reconstructed slag and Fe 3+ The mass volume ratio of the leaching solution is 1:(1-20) g / mL, the leaching temperature is 10-100° C., and the leaching time is 10-180 min.

[0018] As a preferred technical solution of the present invention, the electrolysis in step (3) is carried out in a diaphragm electrolytic cell with a current density of 50 to 500 A / m 2 The electrolysis time is 20 to 200 minutes. After the electrolysis recovery of copper is completed, the remaining Fe 2+ Cu in solution 2+ Content ≤0.5g / L.

[0019] Compared with the prior art, the present invention has at least the following beneficial effects:

[0020] (1) The physical phase reconstruction of the waste chips is achieved by roasting, so that the copper is exposed and the copper leaching effect is improved.

[0021] (2) The present invention provides a method for recovering copper from waste chips. The method has the characteristics of short process flow, continuous operation, green cleaning, simple operation, low cost and high comprehensive recovery value. The copper leaching agent has the characteristics of being green, low cost, wide source and recyclable. The entire wet recovery process does not generate wastewater and waste gas, and has significant economic and environmental benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 A schematic diagram of the process flow of the method for recovering copper from waste chips provided by the present invention;

[0023] Figure 2 The XRD diagram of the waste chip before and after high temperature calcination in Example 1 of the present invention;

[0024] Figure 3 This is a comparison chart of copper leaching rates of uncalcined (Comparative Example 1) and calcined (Example 1) waste chips provided by the present invention.

[0025] The present invention is further described in detail below. However, the following examples are only simplified examples of the present invention and do not represent or limit the scope of protection of the present invention. The scope of protection of the present invention shall be subject to the claims. DETAILED DESCRIPTION

[0026] The technical solution of the present application is further described below through specific implementation methods.

[0027] A specific embodiment of the present invention provides a method for recovering copper from waste chips, the method comprising the following steps:

[0028] (1) calcining waste chips to reconstruct the phase and obtain copper-containing reconstructed slag, wherein the waste chips have a copper content of 10 to 60 wt%, a silicon content of 5 to 50 wt%, and a precious metal content of 0.01 to 0.1%;

[0029] (2) Fe 3+ The leaching solution is mixed with the copper-containing reconstructed slag obtained in step (1) for leaching to obtain a copper-containing leaching solution and leaching slag;

[0030] (3) Using the copper-containing leaching solution obtained in step (2) as the cathode liquid for diaphragm electrolysis to recover copper, the anode liquid is Fe 2+ Solution, Fe 2+ The concentration is 0.1~5mol / L; the cathode chamber obtains copper and Fe 2+ solution, Fe in the anode compartment 2+ The solution is oxidized to form Fe 3+ leachate.

[0031] (4) Fe remaining in the cathode chamber after copper electrolysis recovery is completed 2+ The solution is used as the anode liquid to be electrolyzed and finally enters the anode chamber for electrolytic oxidation. The Fe 3+ The leaching solution is recycled and used for leaching the copper-containing reconstituted slag.

[0032] In the present invention, the copper-containing waste chips are firstly calcined at high temperature to reconstruct the physical phase. After the copper-containing waste chips are reconstructed, the surface of the silicon package is structurally broken, thereby exposing the metal Cu, which is more conducive to the leaching of copper. 3+ The solution selectively leaches Cu in the reconstructed slag to obtain Cu-containing 2+ and Fe 2+ The leaching solution and the leaching residue rich in precious metals; the leaching solution is used as the cathode electrolyte for electrolysis to recover copper, and the anode liquid is Fe 2+ solution, which is electrolytically oxidized to form Fe 3+ Leachate. The remaining Fe in the cathode chamber after the electrolytic recovery of copper is completed 2+ The solution is used as the anode liquid to be electrolyzed and finally enters the anode chamber for electrolytic oxidation to obtain Fe 3+solution, the Fe 3+ The solution can be further used to reconstruct the selective leaching of copper in the slag, thereby achieving Fe 3+ The method realizes the green and efficient recovery of copper from copper-containing waste chips, the enrichment of precious metals and the recovery of Fe 3+ Recycling of solution.

[0033] In a specific embodiment of the present invention, the waste chips include silicon, copper and precious metal elements. The precious metal elements include any one or more combinations of gold, silver and palladium.

[0034] In a specific embodiment of the present invention, the gold content in the waste chip is 10-100 g / t, for example, 10 g / t, 20 g / t, 30 g / t, 40 g / t, 50 g / t, 60 g / t, 70 g / t, 80 g / t, 90 g / t or 100 g / t, etc.; the silver content is 0.01-0.08 wt%, for example, 0.01 wt%, 0.02 wt%, 0.03 wt%, 0.04 wt%, 0.05 wt%, 0.06 wt%, 0.07 wt% or 0.08 wt%, etc.; the platinum content is 0-3 g / t, for example For example, it can be 0g / t, 0.5g / t, 1.0g / t, 1.5g / t, 2.0g / t, 2.5g / t or 3.0g / t; the palladium content is 50-100g / t, for example, it can be 50g / t, 60g / t, 70g / t, 80g / t, 90g / t or 100g / t; the rhodium content is 0-1g / t, for example, it can be 0g / t, 0.2g / t, 0.4g / t, 0.6g / t, 0.8g / t or 1.0g / t, but it is not limited to the listed values, and other values ​​not listed within the above numerical ranges are equally applicable.

[0035] In a specific embodiment of the present invention, the calcination temperature is 100-1000°C, such as 100°C, 200°C, 300°C, 400°C, 500°C, 600°C, 700°C, 800°C, 900°C or 1000°C, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, preferably 400-800°C.

[0036] In a specific embodiment of the present invention, the calcination time is 20 to 200 min, such as 20 min, 40 min, 60 min, 80 min, 100 min, 120 min, 140 min, 160 min, 180 min or 200 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0037] In the present invention, roasting causes the surface structure of the waste chip to undergo a phase transformation, and the surface structure is broken. If the insulation time is too long, other components in the waste chip may undergo a phase transformation, which is not conducive to the subsequent extraction of copper and enrichment of precious metals in the reconstructed slag.

[0038] In one embodiment of the present invention, calcination is performed in an oxidizing atmosphere, such as air and oxygen.

[0039] In one specific embodiment of the present invention, Fe 3+ The concentration of the leachate is 0.1-5 mol / L, such as 0.1 mol / L, 0.5 mol / L, 1 mol / L, 1.5 mol / L, 2 mol / L, 2.5 mol / L, 3 mol / L, 3.5 mol / L, 4 mol / L, 4.5 mol / L or 5 mol / L, but is not limited to the listed values. Other values ​​not listed within the numerical range are also applicable, preferably 0.5-2 mol / L.

[0040] In one embodiment of the present invention, the copper-containing reconstructed slag and Fe 3+ The mass volume ratio of the leachate is 1: (1-20) g / mL, such as 1: 1 g / mL, 1: 2 g / mL, 1: 4 g / mL, 1: 6 g / mL, 1: 8 g / mL, 1: 10 g / mL, 1: 12 g / mL, 1: 14 g / mL, 1: 16 g / mL, 1: 18 g / mL or 1: 20 g / mL, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, preferably 1: (5-15) g / mL.

[0041] In a specific embodiment of the present invention, the leaching temperature is 10 to 100°C, such as 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C, 80°C, 90°C or 100°C, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, preferably 20 to 80°C.

[0042] In a specific embodiment of the present invention, the leaching time is 10 to 180 min, such as 10 min, 20 min, 40 min, 60 min, 80 min, 100 min, 120 min, 140 min, 160 min, 180 min or 200 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0043] In a specific embodiment of the present invention, leaching is performed to separate solid from liquid to obtain leachate and leach residue. The solid-liquid separation method includes any one or a combination of at least two of filtration, centrifugation or decantation, wherein a typical but non-limiting combination is a combination of filtration and centrifugation, a combination of filtration and decantation, a combination of centrifugation and decantation, a combination of filtration, centrifugation and decantation, and a combination of filtration, centrifugation and decantation.

[0044] In a specific embodiment of the present invention, the leached residue comprises any one or a combination of at least two of silicon, silicon dioxide, and precious metals, wherein typical but non-limiting combinations are a combination of silicon and silicon dioxide, a combination of silicon dioxide and precious metals, a combination of silicon and precious metals, a combination of silicon, silicon dioxide and precious metals, and the like.

[0045] In a specific embodiment of the present invention, any one or a combination of at least two of gold, silver, platinum, palladium and rhodium, wherein typical but non-limiting combinations are a combination of gold and silver, a combination of silver and platinum, a combination of platinum and palladium, a combination of palladium and rhodium, a combination of gold, silver and palladium, a combination of platinum, palladium and rhodium, and the like.

[0046] In one embodiment of the present invention, the current density of the electrolysis is 50 to 500 A / m 2 , such as 50A / m 2 , 100A / m 2 , 150A / m 2 , 200A / m 2 , 250A / m 2 、300A / m 2 、350A / m 2 , 400A / m 2 、450A / m 2 or 500A / m 2 The above values ​​are not limited to the above values. Other values ​​not listed in the above values ​​are also applicable. The above values ​​are preferably 100 to 300 A / m. 2 .

[0047] In a specific embodiment of the present invention, the electrolysis time is 20 to 200 min, such as 20 min, 40 min, 60 min, 80 min, 100 min, 120 min, 140 min, 160 min, 180 min or 200 min, but is not limited to the listed values. Other unlisted values ​​within the numerical range are also applicable, preferably 50 to 150 min.

[0048] In a specific embodiment of the present invention, the electrolysis is carried out in a diaphragm electrolyzer, such as a plate-and-frame diaphragm electrolyzer, and the diaphragm is an anion membrane.

[0049] In one embodiment of the present invention, the leaching solution is used as the cathode liquid, Fe 2+solution as the anolyte.

[0050] In one embodiment of the present invention, after the electrolytic recovery of copper is completed, the Fe 2+ Cu in solution 2+ Content ≤ 0.5g / L, the remaining Fe in the cathode chamber 2+ The solution is used as the anode liquid to be electrolyzed and finally enters the anode chamber for electrolytic oxidation. The Fe 3+ The leaching solution is recycled and used for leaching the copper-containing reconstituted slag.

[0051] In a specific embodiment of the present invention, the method for recovering copper from waste chips comprises:

[0052] (1) calcining the waste chips having a copper content of 10 to 60 wt % at 400 to 800° C. for 20 to 200 min to reconstruct the physical phase and obtain copper-containing reconstructed slag;

[0053] (2) The copper-containing reconstructed slag and Fe 3 Concentration of 0.1~5mol / L Fe 3+ The leaching solutions are mixed in a mass volume ratio of 1:(1-20) g / mL, and leached at 10-100° C. for 10-180 min to obtain a copper-containing leaching solution and leaching residue;

[0054] (3) electrolyzing the copper-containing leaching solution in a diaphragm electrolytic cell at a current density of 50 to 500 A / m 2 , the time is 20 to 200 minutes, and the cathode chamber obtains copper and Fe 2+ Electrolyte, after the electrolytic recovery of copper is completed, the remaining Fe 2+ Cu in solution 2+ Content ≤0.5g / L, Fe is obtained in the anode chamber 3+ The leaching solution is recycled and used for leaching the copper-containing reconstructed slag;

[0055] (4) Fe remaining in the cathode chamber after copper electrolysis recovery is completed 2+ The solution is used as the anode liquid to be electrolyzed and finally enters the anode chamber for electrolytic oxidation. The Fe 3+ The leaching solution is recycled and used for leaching the copper-containing reconstituted slag.

[0056] To better illustrate the present invention and facilitate understanding of the technical solution of the present invention, typical but non-limiting embodiments of the present invention are as follows:

[0057] Example 1

[0058] This embodiment provides a method for recovering copper from waste chips, and the process is as follows: Figure 1 As shown, the method comprises the following steps:

[0059] (1) 500 g of untreated waste chips were calcined at 600°C for 120 min to reconstruct the phase and obtain reconstructed slag containing copper phase, with a copper leaching rate of 99%;

[0060] (2) The reconstructed slag was mixed with 1 mol / L Fe 3+ The solutions were mixed and leached for 120 min at a temperature of 80 °C and a solid-liquid ratio of 1:12 g / mL. The solid-liquid separation gave Cu 2+ and Fe 2+ Solutions and enriched slag containing precious metals;

[0061] (3) Using the leaching solution as the cathode solution, Fe 2+ The solution is the anolyte, the titanium sheet and the graphite sheet are the cathode and anode respectively. At a current density of 220A / m 2 , the electrolysis time is 90min, and the copper purity is as high as 99.78%. 2+ Cu in solution 2+ The content is 0.05g / L;

[0062] (4) Fe remaining in the cathode chamber 2+ The solution is used as the anode liquid to be electrolyzed and finally enters the anode chamber for electrolytic oxidation to form 1 mol / L Fe 3+ The leaching solution is recycled for leaching the copper-containing reconstructed slag, with cathode efficiency and anode efficiency of 97.69% and 97.78% respectively, and a copper recovery rate of up to 99.89%.

[0063] Example 2

[0064] This embodiment provides a method for recovering copper from waste chips, the method comprising the following steps:

[0065] (1) 500 g of untreated waste chips were calcined at 600° C. for 120 min to reconstruct the phase and obtain reconstructed slag containing copper phase;

[0066] (2) The reconstructed slag was mixed with 1 mol / L Fe 3+ The solutions were mixed and leached for 120 min at a temperature of 60 °C and a solid-liquid ratio of 1:12 g / mL. The solid-liquid separation gave Cu 2+ and Fe 2+ Solutions and enriched slag containing precious metals;

[0067] (3) Using the Cu 2+ and Fe 2+ The solution was used as cathode solution, titanium sheet and graphite sheet were used as cathode and anode respectively, and the current density was 220A / m 2, the electrolysis time is 90min, and the copper purity is as high as 99.75%. 2+ Cu in solution 2+ The content is 0.1g / L;

[0068] (4) Fe remaining in the cathode chamber 2+ The solution is used as the anode liquid to be electrolyzed and finally enters the anode chamber for electrolytic oxidation to form 1 mol / L Fe 3+ The leaching solution is recycled for leaching the copper-containing reconstructed slag, with cathode efficiency and anode efficiency of 96.43% and 97.71% respectively, and a copper recovery rate of up to 95.99%.

[0069] Example 3

[0070] This embodiment provides a method for recovering copper from waste chips, the method comprising the following steps:

[0071] (1) 500 g of untreated waste chips were calcined at 800° C. for 120 min to reconstruct the phase and obtain reconstructed slag containing copper phase;

[0072] (2) The reconstructed slag was heated to 1 mol / L Fe 3+ The solutions were mixed and leached for 60 min at a temperature of 80 °C and a solid-liquid ratio of 1:12 g / mL. The solid-liquid separation gave Cu 2+ and Fe 2+ Solutions and enriched slag containing precious metals;

[0073] (3) Using the Cu 2+ and Fe 2+ The solution was used as cathode solution, titanium sheet and graphite sheet were used as cathode and anode respectively, and the current density was 220A / m 2 , the copper was recovered under the condition of electrolysis time of 60min, and the purity of the recovered copper was as high as 99.77%. 2+ Cu in solution 2+ The content is 0.08g / L;

[0074] (4) Fe remaining in the cathode chamber 2+ The solution is used as the anode liquid to be electrolyzed and finally enters the anode chamber for electrolytic oxidation to form 1 mol / L Fe 3+ The leaching solution is recycled for leaching the copper-containing reconstructed slag, with cathode efficiency and anode efficiency of 95.69% and 96.28% respectively, and a copper recovery rate of up to 96.99%.

[0075] Example 4

[0076] This embodiment provides a method for recovering copper from waste chips, the method comprising the following steps:

[0077] (1) 2 kg of untreated waste chips were calcined at 600° C. for 60 min to reconstruct the physical phase and obtain reconstructed slag containing a copper phase;

[0078] (2) The reconstructed slag was heated to 3 mol / L Fe 3+ The solutions were mixed and leached for 120 min at a temperature of 80 °C and a solid-liquid ratio of 1:4 g / mL. The solid-liquid separation gave Cu 2+ and Fe 2+ Solutions and enriched slag containing precious metals;

[0079] (3) Using the Cu 2+ and Fe 2+ The solution was used as cathode solution, titanium sheet and graphite sheet were used as cathode and anode respectively, and the current density was 220A / m 2 , the electrolysis time is 90min, and the copper purity is as high as 99.78%. 2+ Cu in solution 2+ The content is 0.06g / L;

[0080] (4) Fe remaining in the cathode chamber 2+ The solution is used as the anode liquid to be electrolyzed and finally enters the anode chamber for electrolytic oxidation to form 3 mol / L Fe 3+ The leaching solution is recycled for leaching the copper-containing reconstructed slag, with cathode efficiency and anode efficiency of 98.51% and 98.73% respectively, and a copper recovery rate of up to 99.88%.

[0081] Example 5

[0082] This embodiment provides a method for recovering copper from waste chips, the method comprising the following steps:

[0083] (1) 200 g of untreated waste chips were calcined at 600° C. for 120 min to reconstruct the phase and obtain reconstructed slag containing copper phase;

[0084] (2) The reconstructed slag was heated to 1.5 mol / L Fe 3+ The solutions were mixed and leached for 120 min at a temperature of 80 °C and a solid-liquid ratio of 1:12 g / mL. The solid-liquid separation gave Cu 2+ and Fe 2+ Solutions and enriched slag containing precious metals;

[0085] (3) Using the Cu 2+ and Fe 2+ The solution was used as cathode solution, titanium sheet and graphite sheet were used as cathode and anode respectively, and the current density was 220A / m 2, the electrolysis time is 90min, and the copper purity is as high as 99.77%. 2+ Cu in solution 2+ The content is 0.07g / L;

[0086] (4) Fe remaining in the cathode chamber 2+ The solution is used as the anode liquid to be electrolyzed and finally enters the anode chamber for electrolytic oxidation to form 1.5 mol / L Fe 3+ The leaching solution is recycled for leaching the copper-containing reconstructed slag, with cathode efficiency and anode efficiency of 95.29% and 96.48% respectively, and a copper recovery rate of up to 97.99%.

[0087] Example 6

[0088] This embodiment provides a method for recovering copper from waste chips, the method comprising the following steps:

[0089] (1) 500 g of untreated waste chips were calcined at 400° C. for 200 min to reconstruct the phase and obtain reconstructed slag containing copper phase;

[0090] (2) The reconstructed slag was heated to 5 mol / L Fe 3+ The solutions were mixed and leached for 180 min at a temperature of 20 °C and a solid-liquid ratio of 1:1 g / mL. The solid-liquid separation gave Cu 2+ and Fe 2+ Solutions and enriched slag containing precious metals;

[0091] (3) Using the Cu 2+ and Fe 2+ The solution was used as cathode solution, titanium sheet and graphite sheet were used as cathode and anode respectively, and the current density was 100A / m 2 , the electrolysis time is 150min, and the copper purity is as high as 98.93%. 2+ Cu in solution 2+ The content is 0.06g / L;

[0092] (4) Fe remaining in the cathode chamber 2+ The solution is used as the anode liquid to be electrolyzed and finally enters the anode chamber for electrolytic oxidation to form 5 mol / L Fe 3+ The leaching solution was recycled for leaching the copper-containing reconstructed slag, with cathode efficiency and anode efficiency of 97.32% and 98.56% respectively, and a copper recovery rate of 52.5%.

[0093] Example 7

[0094] This embodiment provides a method for recovering copper from waste chips, the method comprising the following steps:

[0095] (1) 500 g of untreated waste chips were calcined at 1000° C. for 20 min to reconstruct the phase and obtain reconstructed slag containing copper phase;

[0096] (2) The reconstructed slag was heated to 0.5 mol / L Fe 3+ The solutions were mixed and leached for 20 min at a temperature of 100 °C and a solid-liquid ratio of 1:15 g / mL. The solid-liquid separation gave Cu 2+ and Fe 2+ Solutions and enriched slag containing precious metals;

[0097] (3) Using the Cu 2+ and Fe 2+ The solution was used as cathode solution, titanium sheet and graphite sheet were used as cathode and anode respectively, and the current density was 300A / m 2 , the copper was recovered under the condition of electrolysis time of 50min, and the purity of the recovered copper was as high as 95.21%. 2+ Cu in solution 2+ The content is 0.06g / L;

[0098] (4) Fe remaining in the cathode chamber 2+ The solution is used as the anode liquid to be electrolyzed and finally enters the anode chamber for electrolytic oxidation to form 0.5 mol / L Fe 3+ The leaching solution is recycled for leaching the copper-containing reconstructed slag, with cathode efficiency and anode efficiency of 98.01% and 97.43% respectively, and a copper recovery rate of up to 77.22%.

[0099] Comparative Example 1

[0100] This comparative example provides a method for leaching copper from waste chips containing copper. The difference from Example 1 is that the waste chips and Fe 3+ The waste chips were not calcined at high temperature before the solution was mixed, and other conditions remained unchanged. The Cu 2+ and Fe 2+ The leaching rate of Cu in the solution and the enriched slag containing precious metals is 51%.

[0101] The comparative results show that after high-temperature calcination and phase reconstruction, the phase of silicon changes, the diffraction peak of crystalline silicon disappears before and after calcination, and the dense crystalline silicon wrapped in copper is transformed into loose and porous silicon dioxide, exposing more copper, thereby greatly improving the copper leaching rate. The results show that calcination helps to improve the copper leaching rate.

[0102] Test Method

[0103] ICP-OES was used to analyze the Cu 2+The concentration of Fe and total Fe was measured by GB / T7315.1-1987 method. 2+ concentration.

[0104] The test results show that:

[0105] (1) It can be seen from Examples 1 to 5 that the present invention uses the reconstructed slag containing copper phase after high temperature roasting and Fe 3+ After the solution is mixed, as Fe 3+ With the increase of concentration, mixing temperature and mixing time, the leaching rate of copper increases and the enrichment multiples of precious metals also increase.

[0106] (2) It can be seen from Example 1 and Comparative Example 1 that when the waste chip is not calcined and the surface of the waste chip is not reconstructed, the Fe 3+ When the solutions were mixed, the copper leaching rate was only 51% and the enrichment factor was only 1.7;

[0107] (3) XRD test was performed on the waste chips before and after calcination in Example 1. Figure 2 As shown, it can be seen that after sintering, the diffraction peak of crystalline silicon disappears, while other diffraction peaks still exist.

[0108] The applicant declares that the present invention illustrates the detailed structural features of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed structural features, that is, it does not mean that the present invention must rely on the above-mentioned detailed structural features to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the components selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

[0109] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0110] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0111] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for recovering copper from waste chips, characterized in that: The method comprises the following steps: (1) calcining waste chips to reconstruct the phase and obtain copper-containing reconstructed slag, wherein the waste chips have a copper content of 10 to 60 wt%, a silicon content of 5 to 50 wt%, and a precious metal content of 0.01 to 0.1%; (2) Fe 3+ The leaching solution is mixed with the copper-containing reconstructed slag obtained in step (1) for leaching to obtain a copper-containing leaching solution and leaching slag; (3) Using the copper-containing leaching solution obtained in step (2) as the cathode liquid for diaphragm electrolysis to recover copper, the diaphragm is an anion membrane, and the anode liquid is Fe 2+ Solution, Fe 2+ The concentration is 0.1~5mol / L; the cathode chamber obtains metallic copper and Fe 2+ solution, Fe in the anode compartment 2+ The solution is oxidized to form Fe 3+ leachate. (4) Fe remaining in the cathode chamber after copper electrolysis recovery is completed 2+ The solution is used as the anode liquid to be electrolyzed and finally enters the anode chamber for electrolytic oxidation. The Fe 3+ The leaching solution is recycled and used for leaching the copper-containing reconstituted slag.

2. The method according to claim 1, characterized in that The calcination temperature in step (1) is 100 to 1000° C., and the calcination time is 20 to 200 minutes.

3. The method according to claim 1, characterized in that Step (2) Fe 3+ The concentration of the leaching solution is 0.1-5 mol / L, and the copper-containing reconstructed slag and Fe 3+ The mass volume ratio of the leaching solution is 1:(1-20) g / mL, the leaching temperature is 10-100° C., and the leaching time is 10-180 min.

4. The method according to claim 1, characterized in that: The electrolysis in step (3) is carried out in a diaphragm electrolyzer at a current density of 50 to 500 A / m 2 The electrolysis time is 20 to 200 minutes. After the electrolysis recovery of copper is completed, the remaining Fe 2+ Cu in solution 2+ Content ≤0.5g / L.

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