Method for cascade recovery of zinc, indium and lead through cyclone refining

Abstract

The method comprises the following steps: pouring zinc-containing smoke dust on a titanium rod to obtain a rotational flow refining anode column, putting the rotational flow refining anode column into rotational flow refining equipment, adding electrolyte, and starting a rotational flow refining circulating pump to control the turbulent flow velocity to carry out rotational flow refining reaction; and sequentially adjusting the voltage of the cathode, respectively carrying out cyclone refining reaction, and recovering elementary substances and / or oxides of lead, indium and zinc on the cathode. According to the method, under the synergistic effect of the electric field and the turbulent flow field, efficient, stepped and short-process recovery of zinc, indium and lead in the zinc-containing smoke dust is achieved, the technological process is simple, the residual rate of valuable metal in the smoke dust is low, the product purity is high, and good application prospects are achieved.

Description

Technical Field

[0001] The invention relates to the technical field of pollutant treatment, and in particular to a method for recycling zinc, indium and lead by cyclone refining steps. Background Art

[0002] Zinc is one of the most widely used non-ferrous metals, of which about 50% is consumed in galvanizing to protect steel or steel products from corrosion. In addition, zinc has a low melting point (419.5°C) and good fluidity in a molten state. It is often used in the automotive and aviation industries to manufacture various precision castings. Although my country's total zinc resources are very rich, the reserves that can be used for zinc smelting are limited. At the same time, zinc is commonly found in various non-ferrous metal smelting wastes. In 2022, China's zinc production will be about 6.358 million tons, while zinc demand will reach 7.005 million tons, accounting for about 40% of the world's total zinc demand, and it is still growing steadily. Therefore, the comprehensive recycling of zinc renewable resources and the zinc treatment and recovery of zinc-containing smelting waste are crucial.

[0003] Indium metal has the characteristics of good ductility, good conductivity, strong plasticity, low elongation (22%), high boiling point (2109℃), low melting point (156.6℃), etc. Indium can form compounds, semiconductors, special alloys, electronic optical materials and new functional materials with other non-ferrous metals (antimony, arsenic, lead, tin, bismuth, cadmium, etc.), and is widely used in electronics, instrumentation, optical fiber communications, chemicals, atomic energy, national defense, battery corrosion protection and other fields. Indium is a rare metal, mainly dispersed in non-ferrous metal minerals such as zinc and tin as impurities. Therefore, extracting and recovering indium metal from abundant associated metals has always been a key research problem.

[0004] Lead metal is an important industrial material. It is widely used in the electronics industry, construction industry, chemical industry and nuclear industry because of its advantages such as low electrical resistance, low melting point, high corrosion resistance, poor penetration of X-rays and gamma rays, and good plasticity. However, despite the wide range of uses and application value of lead, there are also health and environmental risks that cannot be ignored. Lead-containing wastes generated in mineral processing, metal smelting and industrial processes are hazardous wastes, which pose potential hazards to human health and the ecological environment and must be properly treated and disposed of. Lead-containing wastes can also be used as secondary raw materials for lead recovery, and their recycling has strong economic, environmental and social benefits.

[0005] The zinc-containing smoke generated during the smelting process of steel plants mainly contains 50-60% zinc, 3-4% iron, 0.03-5% indium, 5-10% lead and other valuable metals, which have a high recovery value. At present, the acid leaching-electrowinning process is the main method for the efficient recovery and clean utilization of valuable metals in zinc-containing smoke from steel plants. This method has the problems of complex process flow, low leaching rate of zinc, indium and lead, difficult deposition of zinc and indium, and low product purity. The prior art uses a method for recovering valuable metals by cyclone electrolysis, which has low recovery efficiency of valuable metals, complex process flow and long electrolysis cycle. For example, Chinese patent CN108486606A discloses a method and product of cyclone electrolysis cascade recovery of copper, selenium and tellurium, and adjusts the potential to obtain the single substance or oxide of copper, selenium and tellurium in turn, but it is necessary to configure a mixed solution of metal ions first, which is difficult to apply to the cyclone electrolysis recovery of "difficult to leach" metal ions in solid waste. In addition, cyclonic electrolysis will also produce other impurity metals, resulting in low purity of the cathode zinc, indium and lead products, making subsequent use difficult. Therefore, in order to achieve efficient and clean recovery and full resource utilization of zinc-containing smoke from steel mills, it is urgent to propose a method for cascade recovery of zinc, indium and lead from zinc-containing smoke from steel mills, so that the three valuable metals can be separated in cascades in the same batch, simplify the process steps, shorten the recovery process, reduce the residual rate of valuable metals in zinc-containing smoke from steel mills, improve the purity of cathode products, and increase economic benefits. Summary of the invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a method for cyclone refining stepwise recovery of zinc, indium and lead, which has a short process flow, a high utilization rate of zinc-containing smoke from steel mills, a high recovery rate of zinc, indium and lead in the smoke, a high purity of cathode products (i.e., simple substances and / or oxides of Zn, In and Pb), no secondary pollution, simple operation and low equipment requirements.

[0007] The above object of the present invention is achieved through the following technical solutions:

[0008] A method for recovering zinc, indium and lead by cyclone refining stepwise, comprising the following steps:

[0009] (1) pouring zinc-containing smoke on a titanium rod to obtain a cyclone-refined anode column;

[0010] (2) placing the cyclone refining anode column obtained in step (1) in a cyclone refining device, adding electrolyte, starting the cyclone refining circulation pump to control the turbulent flow rate to 2 to 5 m / s, and performing a cyclone refining reaction;

[0011] (3) adjusting the cathode voltage in sequence, adjusting the cathode voltage to -0.2 to 0.28 V to perform a cyclone refining reaction, and recovering the single substance and / or oxide of lead (Pb) at the cathode; adjusting the cathode voltage to -0.55 to 0.65 V to perform a cyclone refining reaction, and recovering the single substance and / or oxide of indium (In) at the cathode; adjusting the cathode voltage to -0.85 to 0.95 V to perform a cyclone refining reaction, and recovering the single substance of zinc (Zn) at the cathode.

[0012] On the basis of traditional electrolysis technology, cyclone refining technology adds a "turbulent field" to effectively eliminate the adverse effects of concentration polarization on electrolysis. High-speed liquid flow can enhance the directional movement of low-concentration metal cations to the cathode under the action of the electric field. Based on the difference in theoretical precipitation potential of each metal ion, that is, as long as the metal to be extracted has a large potential difference with other metal ions in the solution system, the metal with a more positive potential is easy to precipitate preferentially at the cathode, thereby obtaining an electrolytic product.

[0013] The present invention provides a method for cyclone refining cascade recovery of zinc, indium and lead, which uses "electric field / turbulent field synergistic enhancement" as a means to achieve short-process cascade recovery of multiple metals in zinc-containing smoke from steel mills with the help of "directional transformation" of anode leaching and cathode deposition. On the anode, zinc, indium and lead components in the anode column cast from zinc-containing smoke from the steel mill are continuously electrochemically leached. In addition, under the synergistic effect of the turbulent field, valuable metal phases with good encapsulation and stability, such as zinc sulfide (ZnS), zinc ferrite (ZnFe2O4), indium zinc ferrite (ZnFe 2-m In m O4) and lead sulfate (PbSO4) can be leached out in an enhanced manner to achieve efficient resource recovery of zinc-containing smoke from steel plants. At the cathode, by utilizing the difference in standard electrode potential of each metal ion and the mass transfer enhancement effect of the turbulent field, zinc, indium and lead are directly electrochemically reduced at the cathode to obtain high-purity powder products, namely, single substances and / or oxides of Zn, In and Pb.

[0014] The chemical reactions included in the electrochemical reaction process are:

[0015] Zn 2+ +2e - →Zn

[0016] In 3+ +3e - →In

[0017] Pb 2+ +2e - →Pb

[0018] Furthermore, in step (1), the contents of zinc, indium and lead in the zinc-containing smoke are respectively higher than 20%, 0.1% and 5%.

[0019] Furthermore, in step (1), the casting includes pressing and sintering.

[0020] In a specific embodiment, the casting includes: adding zinc-containing fume into a mold, pressing it on a titanium rod, and then sintering it in an inert gas atmosphere.

[0021] Furthermore, the compacted density is 1.5 to 5.5 g / cm 3 , preferably 2.5 to 3.5 g / cm 3 .

[0022] Furthermore, the sintering time is 10 to 60 minutes, preferably 30 to 40 minutes.

[0023] Furthermore, the sintering temperature is 500-1500°C, preferably 700-1000°C.

[0024] Furthermore, in step (2), the cyclone refining equipment includes a cyclone refining anode column, a cathode, a cyclone refining tank and a cyclone refining circulation pump.

[0025] Furthermore, the cyclone refining anode column is a working electrode.

[0026] Furthermore, the cathode is a stainless steel sheet.

[0027] Furthermore, the cyclone refining tank is a cylindrical electrolytic cell and can be used under normal pressure.

[0028] Furthermore, in step (2), the electrolyte is an aqueous solution of sulfuric acid.

[0029] Furthermore, in step (2), the concentration of sulfuric acid in the aqueous sulfuric acid solution is 0.01 to 0.5 M, preferably 0.05 to 0.2 M, such as 0.05 M, 0.07 M, 0.1 M, 0.12 M, 0.15 M, 0.18 M, 0.2 M. The electrolyte is not a hydrochloric acid solution to prevent chlorine evolution reaction at the anode.

[0030] Furthermore, in step (2), the temperature of the cyclone refining reaction is 10 to 80° C., preferably 20 to 60° C., such as 25° C., 30° C., 35° C., 40° C., 45° C., 50° C., 55° C., 60° C., etc., more preferably 30 to 50° C. The cyclone refining can be carried out at room temperature, which can greatly reduce energy consumption.

[0031] Furthermore, in step (2), the turbulent flow velocity can be 1 m / s, 1.5 m / s, 2 m / s, 2.5 m / s, 3 m / s, 3.5 m / s, 4 m / s or 4.5 m / s, preferably 2 to 3.5 m / s.

[0032] Furthermore, in step (3), the time of each cyclone refining reaction is greater than 2 hours, preferably 2 to 10 hours, for example 2.5 hours, 3 hours, 3.5 hours, 4 hours, 4.5 hours, 5 hours, 6 hours, 7 hours, 8 hours, etc., more preferably 4 to 6 hours.

[0033] Furthermore, in step (3), the cathode is replaced each time a cyclone refining reaction is performed.

[0034] The cathode voltage is adjusted to -0.2 to 0.28 V, such as -0.2 V, -0.23 V, -0.25 V, -0.27 V, etc., to perform a cyclone refining reaction, and the single substance and / or oxide of Pb is recovered at the cathode.

[0035] The cathode voltage is adjusted to -0.55 to 0.65 V, for example -0.55 V, -0.57 V, -0.6 V, -0.62 V, -0.65 V, etc., preferably -0.55 to 0.62 V, to perform cyclone refining reaction, and the simple substance and / or oxide of In is recovered at the cathode.

[0036] The cathode voltage is adjusted to -0.85 to 0.95 V, for example -0.85 V, -0.87 V, -0.9 V, -0.92 V, -0.95 V, etc., preferably -0.87 to 0.95 V, to carry out cyclone refining reaction, and Zn is recovered at the cathode.

[0037] Furthermore, in step (3), after recovering the cathode product, the step of washing the cathode product with water and drying the cathode product is also included.

[0038] Beneficial effects of the present invention:

[0039] (1) The method for cascade recovery of zinc, indium and lead by cyclone refining provided by the present invention is an electrochemical method of "leaching-deposition coupling", which can comprehensively treat zinc-containing smoke in the same batch, simplify the operation process, shorten the reaction time, and realize the short-process cascade recovery of multiple metals.

[0040] (2) The method for cyclone refining stepwise recovery of zinc, indium and lead provided by the present invention is to cast zinc-containing smoke into anode columns, and with the help of "electric field / turbulent field synergistic enhancement" means, effectively solve the problem of "difficult to leach and easy to deposit" or "easy to leach and difficult to deposit" between different metals, thereby reducing the amount of zinc-containing smoke raw materials used in steel plants and reducing the residual rates of zinc, indium and lead.

[0041] (3) The method for cyclone refining stepwise recovery of zinc, indium and lead provided by the present invention uses a titanium rod with good corrosion resistance, avoiding the anode dissolution of traditional stainless steel rods after cyclone refining, and can be sustainably recycled. It only needs to re-cast the zinc-containing smoke from the steel plant on the titanium rod to obtain a new cyclone refining anode column, which reduces costs, facilitates mass production, can bring good economic and social benefits, and has good application prospects.

[0042] (4) Cyclone refining is carried out in a low-concentration electrolyte with mild conditions and low equipment requirements, which reduces equipment loss and maintenance costs. Compared with cyclone refining in a hydrochloric acid electrolyte, it can avoid the interference of the anode chlorine evolution reaction on the leaching of zinc-containing smoke; the low-concentration electrolyte used greatly reduces the acid consumption, and no impurities are introduced during the cyclone refining process, there is no secondary pollution, and it is convenient for the subsequent treatment of waste liquid.

[0043] (5) The method for cyclone refining and stepwise recovery of zinc, indium and lead provided by the present invention obtains a high-purity powdered cathode product, namely, simple substances and / or oxides of Zn, In and Pb, which are convenient for subsequent application and processing and have good economic benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 A schematic diagram of the principle of a method for cyclone refining stepwise recovery of zinc, indium and lead provided by the present invention.

[0045] Figure 2 This is a curve chart showing the variation of the residual rate of zinc, indium or lead in the zinc-containing smoke from the steel plant provided in Example 1 with the time of each cyclone refining stage.

[0046] Figure 3 The present invention provides a curve diagram showing the variation of the residual rate of zinc, indium or lead in the zinc-containing smoke of the steel plant with the turbulent velocity after the cyclone refining stepwise recovery of zinc, indium or lead products (Example 1, Examples 6 to 10 and Comparative Examples 1 to 3) provided by the present invention.

[0047] Figure 4 The present invention provides a curve diagram showing the purity of the cyclone refining step-by-step recovery of Zn, In and Pb products (Example 1, Examples 6 to 10 and Comparative Examples 1 to 3) as a function of turbulent velocity. DETAILED DESCRIPTION

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those generally understood by those skilled in the art of the present invention. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0049] The present invention provides a method for recycling zinc, indium and lead by cyclone refining. The principle diagram is as follows: Figure 1 As shown, the following steps are included:

[0050] (1) pouring zinc-containing smoke on a titanium rod to obtain a cyclone-refined anode column;

[0051] (2) placing the cyclone refining anode column obtained in step (1) in a cyclone refining device, adding electrolyte, starting the cyclone refining circulation pump to control the turbulent flow rate to 2 to 5 m / s, and performing a cyclone refining reaction;

[0052] (3) adjusting the cathode voltage in sequence, adjusting the cathode voltage to -0.2 to 0.28 V to perform a cyclone refining reaction, and recovering the single substance and / or oxide of lead (Pb) at the cathode; adjusting the cathode voltage to -0.55 to 0.65 V to perform a cyclone refining reaction, and recovering the single substance and / or oxide of indium (In) at the cathode; adjusting the cathode voltage to -0.85 to 0.95 V to perform a cyclone refining reaction, and recovering the single substance of zinc (Zn) at the cathode.

[0053] In a specific embodiment, the method for recovering zinc, indium and lead by cyclone refining stepwise comprises the following steps:

[0054] (1) Using zinc-containing dust from steel mills as raw material, the concentration of zinc is 1.5-5.5 g / cm 3 The pressed density, sintering time of 10 to 60 minutes and sintering temperature of 500 to 1500° C. are poured on a titanium rod to obtain a cyclone refined anode column;

[0055] (2) placing the cyclone refining anode column obtained in step (1) in a cyclone refining device, using a S32101 stainless steel sheet as a cathode, a 0.01-0.5M sulfuric acid aqueous solution as an electrolyte, starting a cyclone refining circulation pump to control the turbulent flow rate to 2-5 m / s, and performing a cyclone refining reaction at an electrolysis temperature of 10-80° C.;

[0056] (3) adjusting the cathode voltage in sequence, adjusting the cathode voltage to -0.2 to 0.28 V to carry out a cyclone refining reaction for lead separation for 2 to 10 hours; after the reaction is completed, replacing the cathode stainless steel sheet, adjusting the cathode voltage to -0.55 to 0.62 V to carry out a cyclone refining reaction for indium separation for 2 to 10 hours; after the reaction is completed, replacing the cathode stainless steel sheet again, adjusting the cathode voltage to -0.87 to 0.95 V, and carrying out a cyclone refining reaction for zinc separation for 2 to 10 hours;

[0057] (4) The reaction product on the cathode S32101 stainless steel sheet in step (3) is peeled off, washed with deionized water, and dried to obtain high-purity Zn, In and Pb products (single substances and / or oxides).

[0058] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it, but the embodiments are not intended to limit the present invention.

[0059] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods, and the materials, reagents, etc. used are all available from commercial sources unless otherwise specified.

[0060] In the following examples and comparative examples, the zinc-containing fume used is zinc-containing fume from a steel plant with zinc, indium and lead contents of approximately 45%, 0.8% and 7%, respectively.

[0061] Example 1

[0062] A method for recovering zinc, indium and lead by cyclone refining stepwise, comprising the following steps:

[0063] (1) Using zinc-containing dust from a steel mill as raw material, 3 The pressed density, sintering time of 30 min and sintering temperature of 800°C were cast on a titanium rod to obtain a cyclone refined anode column;

[0064] (2) placing the cyclone refining anode column obtained in step (1) in a cyclone refining device, using a S32101 stainless steel sheet as a cathode and a 0.1M sulfuric acid aqueous solution as an electrolyte, starting a cyclone refining circulation pump to control the turbulent flow rate to 3 m / s, and performing a cyclone refining reaction at an electrolysis temperature of 40° C.;

[0065] (3) adjusting the cathode voltage in sequence, adjusting the cathode voltage to -0.25V to carry out the cyclone refining reaction of lead separation for 6 hours; after the reaction is completed, replacing the cathode stainless steel sheet, adjusting the cathode voltage to -0.57V to carry out the cyclone refining reaction of indium separation for 6 hours; after the reaction is completed, replacing the cathode stainless steel sheet again, adjusting the cathode voltage to -0.92V, and carrying out the cyclone refining reaction of zinc separation for 4 hours;

[0066] (4) The reaction product on the cathode S32101 stainless steel sheet in step (3) is peeled off, washed with deionized water, and dried to obtain high-purity Zn, In and Pb products.

[0067] XRF and ICP-OES were used to detect cathode products and anode residual waste slag. The test results showed that the purity of Zn, In and Pb products were 98.2%, 97.6% and 96.8% respectively. At the same time, the residual rates of Zn, In and Pb in the zinc-containing smoke of the steel plant were 1.3%, 3.4% and 4.6% respectively.

[0068] Figure 2 This is a curve chart showing the variation of the residual rate of zinc, indium or lead in the zinc-containing smoke from the steel plant provided in Example 1 with the time of each cyclone refining stage.

[0069] Example 2

[0070] A method for recovering zinc, indium and lead by cyclone refining stepwise, which is basically the same as Example 1, except that: in step (1), the pressing density is 2.75 g / cm 3 .

[0071] XRF and ICP-OES were used to detect cathode products and anode residual waste slag. The test results showed that the purity of Zn, In and Pb products were 98.3%, 98.2% and 97.1%, respectively. At the same time, the residual rates of Zn, In and Pb in the zinc-containing smoke of the steel plant were 1.1%, 3.1% and 3.2%, respectively.

[0072] Example 3

[0073] A method for recovering zinc, indium and lead by cyclone refining stepwise, which is basically the same as Example 1, except that: in step (1), the pressing density is 5g / cm 3 .

[0074] XRF and ICP-OES were used to test the cathode products and the residual anode slag. The test results showed that the purity of Zn, In and Pb products were 65.6%, 88.4% and 95.2% respectively. At the same time, the residual rates of Zn, In and Pb in the zinc-containing dust of the steel plant were 11.2%, 14.5% and 18.2% respectively. Due to the high compaction density of the zinc-containing dust of the steel plant, it is difficult for the zinc, indium and lead components to be fully leached under the strengthening effect of the "turbulent field", resulting in a high residual rate.

[0075] Example 4

[0076] A method for recovering zinc, indium and lead by cyclone refining stepwise is basically the same as that of Example 1, except that in step (1), the sintering temperature is 900°C.

[0077] XRF and ICP-OES were used to detect cathode products and anode residual waste slag. The test results showed that the purity of Zn, In and Pb products were 98%, 98.4% and 97.2%, respectively. At the same time, the residual rates of Zn, In and Pb in the zinc-containing smoke of the steel plant were 1.1%, 3.2% and 3.8%, respectively.

[0078] Example 5

[0079] A method for recovering zinc, indium and lead by cyclone refining stepwise is basically the same as that of Example 1, except that in step (2), the concentration of the aqueous sulfuric acid solution is 0.5M.

[0080] The cathode products and anode residual waste residues were tested by XRF and ICP-OES, and the test results showed that the purity of Zn, In and Pb products were 98.4%, 98.5% and 97.4% respectively, and the residual rates of Zn, In and Pb in zinc-containing smoke from steel mills were 0.9%, 2.4% and 3.1% respectively. High-concentration electrolyte is conducive to strengthening the leaching of zinc, indium and lead components, and slightly reducing the residual rates of Zn, In and Pb in zinc-containing smoke from steel mills, but high-concentration electrolyte is not only easy to corrode cyclone refining equipment, including titanium rods, stainless steel sheets and cyclone refining tanks, but also increases the subsequent treatment cost of waste electrolyte.

[0081] Example 6

[0082] A method for recovering zinc, indium and lead by cyclone refining stepwise is basically the same as that of Example 1, except that in step (2), the turbulent flow velocity is 2 m / s.

[0083] Example 7

[0084] A method for recovering zinc, indium and lead by cyclone refining stepwise is basically the same as that of Example 1, except that in step (2), the turbulent flow velocity is 2.5 m / s.

[0085] XRF and ICP-OES were used to detect cathode products and anode residual waste slag. The test results showed that the purity of Zn, In and Pb products were 89.8%, 94.2% and 95.6%, respectively. At the same time, the residual rates of Zn, In and Pb in the zinc-containing smoke of the steel plant were 3.2%, 8.4% and 12.1%, respectively.

[0086] Example 8

[0087] A method for recovering zinc, indium and lead by cyclone refining stepwise is basically the same as that of Example 1, except that in step (2), the turbulent flow velocity is 3.5 m / s.

[0088] XRF and ICP-OES were used to detect cathode products and anode residual waste slag. The test results showed that the purity of Zn, In and Pb products were 98.4%, 98.2% and 96.8% respectively. At the same time, the residual rates of Zn, In and Pb in the zinc-containing smoke of the steel plant were 1.1%, 3.2% and 3.4% respectively.

[0089] Example 9

[0090] A method for recovering zinc, indium and lead by cyclone refining stepwise is basically the same as that of Example 1, except that in step (2), the turbulent flow velocity is 4 m / s.

[0091] Example 10

[0092] A method for recovering zinc, indium and lead by cyclone refining stepwise is basically the same as that of Example 1, except that in step (2), the turbulent flow velocity is 5 m / s.

[0093] Embodiment 11

[0094] A method for recovering zinc, indium and lead by cyclone refining stepwise is basically the same as that of Example 1, except that in step (3), the cathode voltage is adjusted to -0.27 V to carry out cyclone refining reaction for lead separation for 6 hours.

[0095] XRF and ICP-OES were used to detect cathode products and anode residual waste slag. The test results showed that the purity of Zn, In and Pb products were 98.4%, 97.8% and 96.4% respectively. At the same time, the residual rates of Zn, In and Pb in the zinc-containing smoke of the steel plant were 1.2%, 3.5% and 4.1% respectively.

[0096] Example 12

[0097] A method for cyclone refining stepwise recovery of zinc, indium and lead is basically the same as Example 1, except that in step (3), the cathode voltage is adjusted to -0.6V to carry out cyclone refining reaction for indium separation for 6 hours.

[0098] XRF and ICP-OES were used to detect cathode products and anode residual waste slag. The test results showed that the purity of Zn, In and Pb products were 98.4%, 97.1% and 96.7%, respectively. At the same time, the residual rates of Zn, In and Pb in the zinc-containing smoke of the steel plant were 1.2%, 3.1% and 4.2%, respectively.

[0099] Example 13

[0100] A method for cyclone refining stepwise recovery of zinc, indium and lead is basically the same as Example 1, except that in step (3), the cathode voltage is adjusted to -0.9V to carry out cyclone refining reaction for zinc separation for 4 hours.

[0101] XRF and ICP-OES were used to detect cathode products and anode residual waste slag. The test results showed that the purity of Zn, In and Pb products were 98.3%, 97.6% and 96.8% respectively. At the same time, the residual rates of Zn, In and Pb in the zinc-containing smoke of the steel plant were 1.8%, 3.4% and 4.6% respectively.

[0102] Comparative Example 1

[0103] A method for recovering zinc, indium and lead by cyclone refining stepwise is basically the same as that of Example 1, except that in step (2), the turbulent flow velocity is 1 m / s.

[0104] XRF and ICP-OES were used to detect the cathode products and anode residual waste residues, and the test results showed that the purity of Zn, In and Pb products were 44.8%, 64.4% and 85.7%, respectively, while the residual rates of Zn, In and Pb in the zinc-containing smoke from the steel plant were 50.2%, 68.2% and 74.2%, respectively. Due to the low flow rate of the "turbulent field", it is difficult to enhance the leaching of Zn, In and Pb components in the zinc-containing smoke from the steel plant, which leads to high residual rates of Zn, In and Pb, and the purity of cathode zinc, indium and lead products is generally reduced.

[0105] Comparative Example 2

[0106] A method for recovering zinc, indium and lead by cyclone refining stepwise is basically the same as that of Example 1, except that in step (2), the turbulent flow velocity is 0.5 m / s.

[0107] XRF and ICP-OES were used to detect the residual waste slag of the anode. The test results showed that the residual rates of Zn, In and Pb in the zinc-containing smoke from the steel plant were 74.6%, 92.2% and 95.4% respectively. Due to the low flow rate of the "turbulent field", the zinc (ZnS, ZnFe2O4 and ZnFe 2-m In m O4), indium (ZnFe 2-m In m The zinc (O4) and lead (PbSO4) components are extremely difficult to leach, and the residual rates of Zn, In and Pb in zinc-containing smoke from steel mills are extremely high, resulting in almost no Zn, In and Pb products being produced at the cathode.

[0108] Comparative Example 3

[0109] A method for recovering zinc, indium and lead by cyclone refining stepwise is basically the same as that of Example 1, except that in step (2), the turbulent flow velocity is 1.5 m / s.

[0110] The curve diagram of the residual rate of zinc, indium and lead in the zinc-containing smoke of the steel plant after the cyclone refining stepwise recovery of zinc, indium and lead products (Example 1, Examples 6 to 10 and Comparative Examples 1 to 3) provided by the present invention as a function of the turbulent velocity is as follows Figure 3 As shown; the purity of the cyclone refining step recovery Zn, In and Pb products (Example 1, Examples 6 to 10 and Comparative Examples 1 to 3) provided by the present invention varies with the turbulent velocity curve as shown Figure 4 shown.

[0111] Comparative Example 4

[0112] A method for recovering zinc, indium and lead by cyclone refining stepwise is basically the same as that of Example 1, except that in step (3), the cathode voltage is adjusted to -0.1V to carry out cyclone refining reaction for lead separation for 6 hours.

[0113] because The voltage is -0.13V, and the cathode will hardly electro-reduced and deposited Pb products. XRF and ICP-OES were used to detect the residual waste residue of the anode. The test results showed that the purity of Zn and In products were 74.6% and 42.4%, respectively. At the same time, the residual rates of Zn, In and Pb in the zinc-containing smoke of the steel plant were 30.1%, 20.4% and 8.2%, respectively. Since the lead component cannot be recycled in priority to the zinc and indium components, the subsequent leached Pb 2+ It will interfere with the cyclone refining reaction of zinc and indium separation, resulting in reduced purity of cathode Zn and In products.

[0114] Comparative Example 5

[0115] A method for cyclone refining stepwise recovery of zinc, indium and lead is basically the same as Example 1, except that in step (3), the cathode voltage is adjusted to -0.3V to carry out cyclone refining reaction for indium separation for 6 hours.

[0116] because The voltage is -0.342V, and the cathode will hardly electro-reduced and deposited In products. XRF and ICP-OES were used to detect the residual waste residue at the anode, and the test results showed that the purity of Zn and Pb products were 28.2% and 95.6%, respectively. At the same time, the residual rates of Zn, In and Pb in the zinc-containing smoke from the steel plant were 36.8%, 22.7% and 4.6%, respectively. Since the indium component cannot be recycled in priority to the zinc component, the subsequent leached In 3+ It will interfere with the cyclone refining reaction of zinc separation, resulting in reduced purity of the cathode Zn product.

[0117] Obviously, the above embodiments of the present invention are only examples for clearly illustrating the present invention, and are not intended to limit the embodiments of the present invention. Those skilled in the art should understand that other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the embodiments here. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the claims of the present invention.

Claims

1. A method for recovering zinc, indium and lead by cyclone refining, characterized in that: The following steps are involved: (1) pouring zinc-containing smoke on a titanium rod to obtain a cyclone-refined anode column; (2) placing the cyclone refining anode column obtained in step (1) in a cyclone refining device, adding electrolyte, starting the cyclone refining circulation pump to control the turbulent flow rate to 2 to 5 m / s, and performing a cyclone refining reaction; (3) adjusting the cathode voltage in sequence, adjusting the cathode voltage to -0.2 to 0.28 V to perform a cyclone refining reaction, and recovering the single substance and / or oxide of lead at the cathode; adjusting the cathode voltage to -0.55 to 0.65 V to perform a cyclone refining reaction, and recovering the single substance and / or oxide of indium at the cathode; adjusting the cathode voltage to -0.85 to 0.95 V to perform a cyclone refining reaction, and recovering the single substance of zinc at the cathode.

2. The method according to claim 1, characterized in that In step (1), the casting includes pressing and sintering.

3. The method according to claim 2, characterized in that The compacted density is 1.5 to 5.5 g / cm 3 .

4. The method according to claim 2, characterized in that: The sintering time is 10 to 60 minutes, and the temperature is 500 to 1500°C.

5. The method according to claim 1, characterized in that In step (2), the cyclone refining equipment includes a cyclone refining anode column, a cathode, a cyclone refining tank and a cyclone refining circulation pump.

6. The method according to claim 5, characterized in that The cathode is a stainless steel sheet.

7. The method according to claim 5, characterized in that The cyclone refining tank is a cylindrical electrolytic tank.

8. The method according to claim 1, characterized in that In step (2), the electrolyte is an aqueous solution of sulfuric acid.

9. The method according to claim 8, characterized in that In step (2), the concentration of sulfuric acid in the aqueous sulfuric acid solution is 0.01 to 0.5 M.

10. The method according to claim 1, characterized in that In step (2), the temperature of the cyclone refining reaction is 10 to 80°C.

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