Method for processing white metal

Abstract

The present application relates to the technical field of white alloy, and in particular to a white alloy processing method.The white alloy processing method comprises the following steps: (a) dividing the white alloy to be processed into n portions, n >= 3; taking the first portion of the white alloy to prepare a first anode; (b) placing the first anode in an electrolyte to perform electrolysis; when a large number of bubbles appear in the region of the first anode, the first anode is taken out and soaked in a fluorine-containing acid solution for treatment, and then placed in the electrolyte again to repeat the electrolysis operation to obtain a first defective anode; (c) mixing the first defective anode with the second portion of the white alloy to prepare a second anode, repeating the operation of step (b) to obtain a second defective anode, and so on until the nth portion of the white alloy is prepared into an nth anode and electrolysis is completed.The present application uses a mixed method mainly based on electrochemical dissolution and assisted by acid dissolution to process the white alloy, and has the advantages of less equipment, simple and convenient process, low production cost and high efficiency.

Description

Technical Field

[0001] This invention relates to the field of white alloy technology, and more specifically, to a method for processing white alloys. Background Technology

[0002] Currently, there are two main methods for processing high-silicon white alloys: one is the wet method, which involves crushing the white alloy and then decomposing it under normal or high pressure with strong acid and oxidant; the other is the pyrometallurgical method, which involves melting the white alloy, adding oxidant to separate cobalt and iron slag from copper, and then leaching the cobalt-iron slag with reducing acid to extract cobalt.

[0003] Both of the above methods involve high-intensity processes, high costs, and are time-consuming and labor-intensive. The wet process first requires addressing the crushing issue. Due to the hardness and wear resistance of white alloys, conventional crushing equipment is very expensive. The common practice is to melt and then quench the material in water, but the resulting particle size is relatively large (in the millimeter range), significantly impacting subsequent oxidation and acid leaching, and also increasing crushing costs. Another option is to use a cemented carbide ball mill, but this is inefficient and even more expensive. During atmospheric pressure leaching, the leaching temperature is very high (above 90℃), and a large amount of strong oxidizing agents (such as sodium chlorate, sodium persulfate, etc.) is added, resulting in a high salt content in the leachate. Therefore, the process requires high precision, high leaching intensity, and high costs. The pyrometallurgical process has a long flow. For leaching cobalt-iron slag, very high leaching temperatures (above 90℃) are also required, along with the addition of large amounts of reducing agents (such as sodium sulfite, sodium metabisulfite, etc.), resulting in a high salt content in the leachate and high costs.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] One objective of this invention is to provide a method for processing white alloys, thereby solving the problems of high breakage and leaching intensity caused by hydrometallurgical processes in the prior art, and the problems of long process flow and high leaching intensity in pyrometallurgical processes.

[0006] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0007] A method for processing white alloys includes the following steps:

[0008] (a) Divide the white alloy to be processed into n parts, n≥3; take the first part of the white alloy to prepare the first anode;

[0009] (b) The first anode is placed in the electrolyte for electrolysis; when a large number of bubbles appear in the first anode area, the first anode is removed and soaked in a fluorine-containing acid solution, and then placed in the electrolyte to repeat the electrolysis operation to obtain a first defective anode, the area of ​​which accounts for 80% to 90% of the original area of ​​the first anode.

[0010] (c) Mix the first defective anode with the second part of white alloy and prepare the second anode. Repeat step (b) to obtain the second defective anode. Continue in this manner until the nth part of white alloy is prepared into the nth anode and the electrolysis is completed.

[0011] During the electrolysis process, copper is deposited at the cathode.

[0012] In one embodiment, the white alloy comprises the following components by mass percentage:

[0013] Co 10% to 45%, Cu 5% to 30%, Fe 15% to 35% and Si 5% to 30%.

[0014] In one embodiment, the electrolyte comprises a sulfuric acid solution; the equivalent concentration of the sulfuric acid solution is 0.1 to 2N.

[0015] In one embodiment, during the electrolysis process, the voltage is 4–10V and the current density is 100–300A / m. 2 .

[0016] In one embodiment, the equivalent concentrations of hydrogen ions and fluoride ions in the fluorine-containing acid solution are 0.1 to 1N, respectively.

[0017] In one embodiment, the fluorine-containing acid solution includes a hydrofluoric acid solution.

[0018] In one embodiment, the soaking treatment time is 0.5 to 1.5 hours.

[0019] In one embodiment, the anode is washed after each immersion treatment during the electrolysis process.

[0020] In one embodiment, the method further includes washing the nth defective anode.

[0021] In one embodiment, when the concentration of copper ions in the electrolyte is above 20 g / L, copper is deposited at the cathode.

[0022] In one embodiment, the cathode is made of stainless steel.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] This invention employs a hybrid method, primarily electrochemical dissolution and secondarily acid dissolution, to treat white alloys. It requires minimal equipment, has a simple and convenient process, and results in low production costs and high efficiency. Detailed Implementation

[0025] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0026] White alloy is an intermediate product containing cobalt, copper, iron, and silicon, obtained from converter slag during copper smelting and then enriched through electric arc furnace matte making and reduction smelting. It is an important secondary resource. In one embodiment, the white alloy of the present invention comprises the following components by mass percentage: Co 10%–45%, Cu 5%–30%, Fe 15%–35%, and Si 5%–30%. The above-mentioned white alloy has a complex distribution of metallic elements and a high silicon content, resulting in widespread inter-phase encapsulation between various metal phases and between silicon dioxide and metal phases, especially the iron silicate phase. This makes the white alloy hard, wear-resistant, corrosion-resistant, and difficult to dissolve, making it difficult to leach valuable elements such as copper and cobalt. In one embodiment, by mass percentage, Co is 10%, 15%, 20%, 25%, 30%, 35%, 40%, or 45%, Cu is 5%, 10%, 15%, 20%, 25%, or 30%, Fe is 15%, 20%, 25%, 30%, or 35%, and Si is 5%, 10%, 25%, or 30%, etc.

[0027] This invention addresses the characteristics of white alloys by proposing a method for processing white alloys, comprising the following steps:

[0028] (a) Divide the white alloy to be processed into n parts, n≥3; take the first part of the white alloy to prepare the first anode;

[0029] (b) The first anode is placed in the electrolyte for electrolysis; when a large number of bubbles appear in the first anode area, the first anode is removed and soaked in a fluorine-containing acid solution, and then placed in the electrolyte to repeat the electrolysis operation to obtain a first defective anode, the area of ​​which accounts for 80% to 90% of the original area of ​​the first anode.

[0030] (c) Mix the first defective anode with the second part of white alloy and prepare the second anode. Repeat step (b) to obtain the second defective anode. Continue in this manner until the nth part of white alloy is prepared into the nth anode and the electrolysis is completed.

[0031] During the electrolysis process, copper is deposited at the cathode.

[0032] This invention uses a mixed method of electrochemical dissolution as the main process and acid dissolution as an auxiliary process to treat white alloys. As can be seen from the structure of white alloys, during electrodissolution, cobalt, copper, and iron can quickly enter the solution, but the dissolution of silicon is very small. After the cobalt, copper, and iron on the surface of the anode plate are dissolved, only silicon and silicon oxide remain on the surface, which will hinder the continued electrodissolution and cause passivation of the anode plate surface. Therefore, a fluorine-containing acid solution is used to dissolve silicon, so that new cobalt, copper, and iron surfaces are exposed to achieve the purpose of activation.

[0033] The method of this invention does not require crushing of the white alloy, nor does it require the addition of oxidizing agents (or reducing agents), which increases the salinity of the solution. It requires less equipment, has a simple and convenient process, low production cost, and high efficiency. In addition, during the process of dissolving the white alloy, copper can be directly electrowinning to obtain cathode copper products, which greatly improves production efficiency.

[0034] In one embodiment, the present invention can complete the decomposition of white alloy using the following three conventional devices: (1) an electric furnace for melting white alloy to cast anode plates; (2) an electrolytic cell for electrodissolving white alloy anode plates; and (3) a silicon washing tank for dissolving silicon during anode plate surface passivation to reactivate the surface.

[0035] When bubbles appear in the anode region, it indicates that the anode's dissolution rate is decreasing. The larger the bubbles, the slower the anode's dissolution rate. When a large number of bubbles are produced, it indicates that the anode is essentially insoluble, and oxygen is being produced through the electrolysis of water.

[0036] In one embodiment, the area of ​​the first defective anode accounts for 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, or 90% of the original area of ​​the first anode. If the proportion is too high, it will affect production efficiency and increase the cost of the cast anode plate; if the proportion is too low, it will affect current efficiency and increase power consumption costs.

[0037] In one embodiment, the electrolyte comprises a sulfuric acid solution; the equivalent concentration of the sulfuric acid solution is 0.1 to 2N, for example, 0.2N, 0.5N, 0.6N, 0.8N, 1N, 1.2N, 1.5N, 1.7N, 2N, etc.

[0038] In one embodiment, the voltage during electrolysis is 4–10V, such as 5V, 6V, 7V, 8V, 9V, etc.; in another embodiment, the current density is 100–300A / m. 2 For example, 120A / m 2 150A / m 2 170A / m 2 200A / m 2 250A / m 2 270A / m 2290A / m 2 Further optimization is achieved with a tank voltage of 5–8V; voltages that are too low or too high will affect current efficiency and increase power consumption costs. A further optimized current density is 120–200 A / m². 2 Too low or too high a value will affect the physical properties and quality of electrolytic copper products.

[0039] In one embodiment, the equivalent concentrations of hydrogen ions and fluoride ions in the fluorine-containing acid solution are 0.1–1N, for example, 0.2N, 0.5N, 0.6N, 0.8N, 0.9N, 1N, etc. Treating the anode surface with a fluorine-containing acid solution of suitable concentration better removes silicon and silicon oxides.

[0040] In one embodiment, the fluorine-containing acid solution includes a hydrofluoric acid solution.

[0041] In one embodiment, the soaking time is 0.5 to 1.5 hours, for example, 0.6 hours, 0.7 hours, 0.8 hours, 0.9 hours, 1 hour, 1.2 hours, 1.4 hours, 1.5 hours, etc.

[0042] In one embodiment, the anode is washed after each immersion treatment during the electrolysis process.

[0043] In one embodiment, the method further includes washing the nth defective anode.

[0044] In one embodiment, as the white alloy dissolves, the copper ion concentration in the solution gradually increases. When the concentration of copper ions in the electrolyte is above 20 g / L, the copper is deposited at the cathode.

[0045] In one embodiment, the anode is in the shape of a sheet.

[0046] In one embodiment, the white alloy can be melted in an electric furnace and refined by electrolytic refining of crude copper using a casting plate equipment.

[0047] In one embodiment, the cathode is made of stainless steel.

[0048] In a preferred embodiment, the method for processing white alloy includes the following steps:

[0049] (a) Divide the white alloy to be processed into n parts, n≥3; take the first part of the white alloy to prepare the first anode;

[0050] (b) The first anode is placed in an electrolytic cell containing an electrolyte solution with an equivalent concentration of 0.1–2N sulfuric acid. The cell voltage is 4–10V, and the current density is 100–300A / m. 2When a large number of bubbles appear in the first anode area, the first anode is removed and soaked in a hydrofluoric acid solution with an equivalent concentration of 0.1-1N for 0.5-1.5 hours. Then, it is placed in the electrolyte and the above electrolysis operation is repeated until the anode dissolves with defects (dissolving with defects means that the white alloy anode plate will have perforations or missing corners during the electrolysis process), thus obtaining the first defective anode. The area of ​​the first defective anode accounts for 80%-90% of the original area of ​​the first anode.

[0051] (c) After removing the first defective anode and rinsing it clean, return it to the electric furnace and mix it with the second part of white alloy to prepare the second anode. Repeat step (b) to obtain the second defective anode. Continue in this manner until the nth part of white alloy is prepared into the nth anode and the electrolysis is completed. During the electrolysis process, when the concentration of copper ions in the electrolyte is above 20 g / L, copper is deposited at the cathode.

[0052] The following explanation, in conjunction with specific embodiments, further clarifies the situation.

[0053] The white alloy in various embodiments of the present invention comprises the following components by mass percentage: Co 25%, Cu 30%, Fe 15%, and Si 30%.

[0054] Example 1

[0055] The processing method for white alloys includes the following steps:

[0056] (a) Divide the white alloy to be processed into n parts, n≥3; take the first part of the white alloy and melt it in an electric furnace, and then cast it to prepare the first anode;

[0057] (b) Electrolysis is performed by placing the first anode in an electrolytic cell containing an electrolyte solution with an equivalent concentration of 1.6N. The cell voltage is 5–8V, and the current density is 120–200A / m. 2 The cathode is made of stainless steel. When a large number of bubbles are generated near the anode plate, the first anode is removed and soaked in a hydrofluoric acid solution with an equivalent concentration of 0.6N for 1 hour. After rinsing it clean, it is placed in the electrolyte and the above electrolysis operation is repeated to obtain the first defective anode. The area of ​​the first defective anode accounts for 80% of the original area of ​​the first anode.

[0058] (c) After removing the first defective anode and rinsing it clean, return it to the electric furnace and mix it with the second batch of white alloy to prepare the second anode. Repeat step (b) to obtain the second defective anode. Repeat the above steps until all the white alloy in the batch is processed. During the electrolysis process, when the concentration of copper ions in the electrolyte is above 20 g / L, copper is deposited at the cathode.

[0059] Example 2

[0060] The processing method for white alloys includes the following steps:

[0061] (a) Divide the white alloy to be processed into n parts, n≥3; take the first part of the white alloy and melt it in an electric furnace, and then cast it to prepare the first anode;

[0062] (b) Electrolysis is performed by placing the first anode in an electrolytic cell containing an electrolyte solution with an equivalent concentration of 0.2N sulfuric acid. The cell voltage is 5–8V, and the current density is 120–200A / m. 2 The cathode is made of stainless steel. When a large number of bubbles are generated near the anode plate, the first anode is removed and soaked in a hydrofluoric acid solution with an equivalent concentration of 1N for 0.5 hours. After rinsing it clean, it is placed in the electrolyte and the above electrolysis operation is repeated to obtain the first defective anode. The area of ​​the first defective anode accounts for 90% of the original area of ​​the first anode.

[0063] (c) After removing the first defective anode and rinsing it clean, return it to the electric furnace and mix it with the second batch of white alloy to prepare the second anode. Repeat step (b) to obtain the second defective anode. Repeat the above steps until all the white alloy in the batch is processed. During the electrolysis process, when the concentration of copper ions in the electrolyte is above 20 g / L, copper is deposited at the cathode.

[0064] Example 3

[0065] The processing method for white alloys includes the following steps:

[0066] (a) Divide the white alloy to be processed into n parts, n≥3; take the first part of the white alloy and melt it in an electric furnace, and then cast it to prepare the first anode;

[0067] (b) Electrolysis is performed by placing the first anode in an electrolytic cell containing an electrolyte solution with a concentration of 2N sulfuric acid. The cell voltage is 5–8V, and the current density is 120–200A / m. 2 The cathode is made of stainless steel. When a large number of bubbles are generated near the anode plate, the first anode is removed and soaked in a hydrofluoric acid solution with an equivalent concentration of 0.1N for 1.5 hours. After rinsing it clean, it is placed in the electrolyte and the above electrolysis operation is repeated to obtain the first defective anode. The area of ​​the first defective anode accounts for 85% of the original area of ​​the first anode.

[0068] (c) After removing the first defective anode and rinsing it clean, return it to the electric furnace and mix it with the second batch of white alloy to prepare the second anode. Repeat step (b) to obtain the second defective anode. Repeat the above steps until all the white alloy in the batch is processed. During the electrolysis process, when the concentration of copper ions in the electrolyte is above 20 g / L, copper is deposited at the cathode.

[0069] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of processing a white alloy, characterized by, The method comprises the following steps: (a) divide the white alloy to be treated into n portions, n≥3; take the first portion of the white alloy to prepare a first anode; (b) place the first anode in an electrolyte to perform electrolysis; when a large number of bubbles appear in the area of the first anode, take out the first anode, and immerse it in a fluorine-containing acid solution for immersion treatment, and then place it in the electrolyte to repeat the electrolysis operation, to obtain a first defective anode, the area of the first defective anode accounts for 80%~90% of the original area of the first anode; (c) mix the first defective anode with the second portion of the white alloy to prepare a second anode, repeat the operation of step (b), to obtain a second defective anode, and so on, until the n portion of the white alloy is prepared into the n anode and the electrolysis is completed; in the process of electrolysis, copper is deposited on the cathode; the white alloy comprises the following components in mass percentage: Co 10%~45%, Cu 5%~30%, Fe 15%~35%, and Si 5%~30%; the electrolyte comprises a sulfuric acid solution; the equivalent concentration of the sulfuric acid solution is 0.1~2N; In the process of the electrolysis, the voltage is 4-10 V, and the current density is 100-300 A / m 2 ; in the fluorine-containing acid solution, the equivalent concentrations of hydrogen ions and fluorine ions are 0.1~1N.

2. The white alloy processing method according to claim 1, characterized by, The fluorine-containing acid solution comprises a hydrofluoric acid solution.

3. The white alloy processing method according to claim 1, characterized by, The immersion treatment time is 0.5~1.5h.

4. The white alloy processing method according to claim 1, characterized by at least one of the following features (1) to (2) is included: (1) in the process of electrolysis, the anode is washed after each immersion treatment; (2) further comprising: washing the n anode.

5. The white alloy processing method according to claim 1, characterized by When the concentration of copper ions in the electrolyte is above 20g / L, the copper is deposited on the cathode.

6. The white alloy processing method according to claim 1, characterized by The material of the cathode comprises stainless steel.