CN105401168A - Method for preparing copper-nickel alloy by electro-deposition of low-grade copper and nickel mixed ore - Google Patents

Abstract

The invention discloses a method for preparing copper-nickel alloy by electrodeposition of low-grade copper-nickel mixed ore. The low-grade copper-nickel mixed ore is used as raw material, and the copper-nickel electrolytic precursor is obtained through oxidation roasting and chlorination roasting successively; The choline/urea ionic liquid is used as the electrolyte; the excess copper-nickel electrolytic precursor is placed in the ionic liquid to form an ionic liquid-copper-nickel salt composite electrolyte; a three-electrode system is used for electrodeposition, that is, the platinum disk electrode is the counter electrode, The polished and acid-activated titanium sheet metal substrate to be plated is used as the working electrode, and the platinum electrode is used as the reference electrode; the electrodeposition reaction is carried out at 60~90°C and -1.30~-1.50V for 60~120 minutes. By adjusting any number of parameters in the reaction temperature, cathode potential and deposition time, the effective control of the growth morphology and size of the copper-nickel alloy is realized. The invention has the characteristics of short process, low energy consumption, high efficiency, low raw material price and the like, and is applied in the technical field of green electrodeposition technology.

Description

Method for preparing copper-nickel alloy by electrodeposition of low-grade copper-nickel mixed ore

technical field

The invention relates to a copper-nickel alloy preparation process, in particular to a method for directly preparing copper-nickel alloy by pretreating copper-nickel mixed ore combined with a hydrometallurgical process, which is applied to the technical field of green metallurgy comprehensive utilization of minerals.

Background technique

Nonferrous metals are widely used in national defense, aerospace, electronic power, transportation, petrochemical and other fields of the national economy, and have an important strategic position in the national economy and national defense construction. However, with the deepening of the development of non-ferrous metal resources, the shortage of non-ferrous metal resources in my country has become increasingly prominent, the self-sufficiency rate of non-ferrous resources in my country has also declined year by year, and the dependence on imports has increased significantly. If things go on like this, it will definitely pose a potential threat to national security. The reason for the above serious situation is that about 75% of my country's proven non-ferrous metal mineral resources are low-grade, polymetallic complex ore and other refractory mineral resources that cannot be economically utilized at present, and these refractory mineral resources are mainly low-grade oxidized mineral resources. - Sulfide mixed ore.

Complex polymetallic mixed ore, its ore composition is diverse, the valuable metal phase is mainly chalcopyrite, pyrrhotite, pentlandite and other sulfide minerals, in addition to magnetite, serpentine and other oxidized minerals and veins stone. For more than 100 years in the modern metallurgical industry, the traditional non-ferrous metal dressing and smelting technology is mainly used to process sulfide ores. At present, most of them use copper-nickel mixed flotation-smelting-high nickel matte crushing, grinding-copper-nickel flotation separation, and then undergo pyromelting and Converting to prepare nickel sulfide/copper electrodes, followed by electrolytic refining to obtain electrodeposited nickel/copper. For high-grade copper-nickel sulfide ore, this treatment method is mature and has high production efficiency. However, when dealing with low-grade mixed ore, there are problems such as low nickel recovery rate and high production cost through pyroprocessing. The mainstream method of wet treatment is acid leaching-selective electrodeposition process, but when the content of iron, magnesium and calcium in the ore is high, the acid consumption of this process is relatively large, and the subsequent purification and impurity removal process is more complicated. Therefore, the traditional dressing and smelting technology for mixed ore cannot be separated and extracted efficiently, and the recovery rate of the main metal is low. It is an inevitable requirement for the efficient utilization of non-ferrous resources to seek a new short-process clean metallurgical process.

Compared with other copper alloys, copper-nickel alloy has excellent mechanical and physical properties. It has good ductility, high hardness, beautiful color, corrosion resistance and rich deep drawing performance. It is widely used in shipbuilding, petrochemical industry, electrical appliances, instruments, medical equipment, Decorative handicrafts and other fields. At present, the preparation methods of copper-nickel alloy mainly include mechanical alloying method, reduction method, ultrasonic method, powder metallurgy method, hydrothermal/solvothermal method, static high pressure synthesis method, etc. Although these synthesis methods can successfully synthesize copper-nickel alloys, most of them are powders of copper-nickel alloys. Nickel, the main additive element in copper-nickel alloy, is a scarce strategic material, which is expensive. It is costly and expensive to prepare copper-nickel alloy directly and in large quantities by smelting and synthesis, which limits the wide application of copper-nickel alloy. At present, the preparation of copper-nickel alloys by galvanostatic deposition has received more and more attention, but the nickel/copper sources required for electrodeposition are still compounds such as nickel sulfate/copper, nickel chloride/copper, nickel nitrate/copper, and a large amount of Active agent and complexing agent. In recent years, the direct preparation of target metals and alloys from complex ores has received more and more attention. The development of low-temperature, high-efficiency, and short-process new green hydrometallurgical processes has become an important research direction for mineral research. How to use low-grade copper-nickel mixed ores The process of directly preparing copper-nickel alloy has become an urgent problem to be solved in the preparation of metal copper-nickel by electrodeposition.

Contents of the invention

In order to solve the problems of the prior art, the purpose of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing copper-nickel alloys by electrodeposition of low-grade copper-nickel mixed ores. For specific low-grade copper-nickel mixed ores, firstly carry out Selective oxidation and chlorination to form chlorinated intermediates of copper and nickel and dissolve in ionic liquids. Finally, copper-nickel alloys are separated by electrochemical controllable deposition. The ionic liquid electrolyte solution can be reused without producing other by-products. Raw materials And the intermediate treatment process is simple, the reaction conditions are easy to realize, and the method of the invention has the characteristics of process controllability, high efficiency, low cost, low energy consumption and the like.

In order to achieve the above-mentioned purpose of invention and creation, the following technical solutions are adopted:

A method for preparing copper-nickel alloy by electrodeposition of low-grade copper-nickel mixed ore, the steps are as follows:

a. Preparation of ionic liquid electrolyte solution: use choline chloride and urea as the initial raw materials, mix the raw materials according to the molar ratio of the raw material components of choline chloride and urea as 1:2, and keep the temperature at 80~100°C Stir for 10-12 hours until a uniform, colorless and transparent ionic liquid is formed as the electrolyte solution;

b. Copper-nickel mixed ore pretreatment: Grind the copper-nickel mixed ore, pass through 200 mesh sieve and then dry, then oxidize and roast the dried ore powder at 600~700℃ in an oxidizing atmosphere After 1~2 hours, the mixed ore powder after oxidation and roasting is chlorinated and roasted. The chlorination roasting is carried out in HCl atmosphere. After the chlorination roasting, the product of the chlorination roasting is cooled to room temperature with the furnace to obtain the chlorination roasting mineral powder; when the copper-nickel mixed ore is pretreated, the oxidative atmosphere gas used in the oxidation roasting process is preferably air; When the copper-nickel mixed ore is pretreated, it is preferable to control the gas flow rate of the oxidizing atmosphere close to 80mL/min during the oxidation roasting process, and to control the HCl gas flow rate close to 80mL/min during the chlorination roasting process.

c. Preparation of copper-nickel saturated ionic liquid: place the chlorinated roasted mineral powder pretreated in step b in the ionic liquid prepared in step a for mixing and dissolving, at 60-100°C Stir at constant temperature for 8-10 hours to obtain a copper-nickel-saturated ionic liquid-copper-nickel salt composite electrolyte;

d. The composition of the electrolytic cell system: the polytetrafluoroethylene beaker is used as the electrolytic cell, the platinum plate electrode is the counter electrode, the polished and acid-activated metal substrate to be plated is the cathode working electrode, and the platinum electrode is used as the reference electrode. The copper-nickel-saturated ionic liquid-copper-nickel salt composite electrolyte prepared in the step c is used as an electrolyte solution to form an electrolytic cell system; preferably, a titanium sheet is used as the cathode of the electrolytic cell system;

e. Electrodeposition preparation process of copper-nickel alloy: keep the electrolytic reaction temperature of the electrolytic cell system formed in the step d at 60~90°C, and then apply a potential of -1.30~-1.50V to the electrolytic cell system Direct current, control the electrodeposition time to 60~120 minutes, and conduct electrodeposition; in the electrodeposition preparation process of copper-nickel alloy, it is preferable to control any number of process parameters in the electrolysis reaction temperature, potential and electrodeposition time parameters to achieve Control of copper-nickel alloy deposition rate and deposition layer thickness;

f. Take out the product obtained by electrodeposition in the step e from the electrolytic cell, first clean it with deionized water, and then wash it several times with absolute ethanol until the product obtained by electrodeposition is cleaned, and finally clean the electrodeposited product The obtained product is dried at low temperature, that is, the copper-nickel alloy is obtained on the surface of the metal substrate to be plated, and the direct enrichment and extraction of the copper-nickel alloy from the low-grade mixed ore is realized.

Principle of the present invention:

The invention accurately controls the potential of the working electrode through the electrochemical three-electrode system, so that the cuprous chloride and nickel chloride dissolved in the electrolyte are reduced to copper-nickel alloy at the working electrode. The invention adopts the method of preparing ionic liquid to realize the enrichment of copper-nickel target elements in low-grade copper-nickel mixed ore. The ionic liquid has wide electrochemical window, high chemical thermal stability, high electrical conductivity, no vapor pressure, non-flammable, It is a new type of green solvent with excellent performance such as secondary recycling. Compared with molten salts, aqueous solutions, and organic solvents, electrodeposition using ionic liquids has a wider electrochemical window, higher current efficiency, lower reaction temperature, and lower corrosion. Due to the advantages of good economy, high added value, and recyclability, the preparation of metals and alloys by electrodeposition in ionic liquids has attracted widespread attention at home and abroad in recent years, especially the electrodeposition of metals and alloys in ionic liquids using chlorides as raw materials. Alloy research is the most extensive and in-depth. Most metal oxides, sulfides or other compounds can react with highly chemically active chlorine under certain conditions, and the selective chlorination of valuable elements in minerals can be achieved by controlling the reaction conditions. Therefore, the present invention aims at the selective chlorination of valuable elements for specific refractory mixed ores, forms chlorinated intermediates and selectively dissolves chlorinated mineral components through specific ionic liquids, and finally combines electrochemical deposition to achieve effective Controlled extraction or alloying of valence components.

Compared with the prior art, the present invention has the following obvious outstanding substantive features and significant advantages:

1. The present invention uses low-grade copper-nickel mixed ore as the main raw material, adopts a short process to prepare copper-nickel alloy, and selectively converts valuable components in the low-grade copper-nickel mixed ore into metal chlorides, and then selectively dissolves them in ion liquid and prepare copper-nickel alloy by electrodeposition;

2. The present invention adopts HCl gas as the chlorination agent, and the chlorination efficiency is high, and the selective chlorination of the target component can be realized by controlling the reaction conditions, and the product is water vapor without the generation of other harmful gases, and the HCl in the tail gas can be recycled ;

3. The present invention uses choline chloride/urea ionic liquid as the electrolyte, which has the advantages of economy, environmental protection, simple preparation, and reusable recycling, and can accurately control the nucleation of deposited copper-nickel alloys by adjusting the electrochemical process parameters Growth;

4. The present invention solves the difficult problem of comprehensive utilization of low-grade copper-nickel mixed ore, and adopts this process to treat mixed ore with convenient operation, simple process, controllable process and no other side reactions. Energy-saving, green and environmentally friendly new technology.

Description of drawings

Fig. 1 is a schematic flow chart of a method for preparing copper-nickel alloy by electrodeposition of low-grade copper-nickel mixed ore according to Embodiment 1 of the present invention.

Fig. 2 is a scanning electron microscope (SEM) image of the surface morphology of the low-grade copper-nickel mixed ore used in Example 1 of the present invention.

Fig. 3 is an X-ray diffraction (XRD) diagram of the low-grade copper-nickel mixed ore used in Example 1 of the present invention.

Fig. 4 is a scanning electron microscope (SEM) image of the surface morphology of the artificial mineral precursor prepared by chlorinating and roasting the low-grade copper-nickel mixed ore in Example 1 of the present invention.

Fig. 5 is an X-ray diffraction (XRD) diagram of an artificial mineral precursor prepared by roasting low-grade copper-nickel mixed ore in Example 1 of the present invention.

Fig. 6 is a scanning electron microscope (SEM) image of the surface morphology of a copper-nickel alloy prepared by electrodeposition in Example 1 of the present invention.

Fig. 7 is an energy spectrum (EDS) diagram of copper-nickel alloy prepared by electrodeposition in Example 1 of the present invention.

Fig. 8 is the current density-time graph of the process of preparing copper-nickel alloy by electrodeposition method in Example 1 and Example 2 of the present invention.

Fig. 9 is an energy spectrum (EDS) diagram of copper-nickel alloy prepared by electrodeposition method in Example 2 of the present invention.

Fig. 10 is an energy spectrum (EDS) diagram of copper-nickel alloy prepared by electrodeposition method in Example 2 of the present invention.

detailed description

Preferred embodiments of the present invention are described in detail as follows:

Embodiment one:

In this embodiment, referring to Figures 1-8, a method for preparing copper-nickel alloy by electrodeposition of low-grade copper-nickel mixed ore, the steps are as follows:

a. Preparation of ionic liquid electrolyte solution: with choline chloride and urea as initial raw materials, first weigh 58.18g of choline chloride and 50g of urea and mix them in a 200mL beaker, and then stir them under constant temperature at 80°C for 12 hours , until a uniform, colorless and transparent ionic liquid is generated, measure 50 mL of the synthesized ionic liquid and place it in a polytetrafluoroethylene beaker for later use;

b. Copper-nickel mixed ore pretreatment: crush and grind the low-grade mixed ore until all the ore powder passes through a 200-mesh sieve and then dry. The finely ground ore powder contains 2.2% nickel, 2.5% copper, and 39.9% iron. As shown in Figure 2 and Figure 3 of the SEM image and XRD of the ore powder, it can be known that the ore powder contains nickel, copper, iron, sulfur and other associated ore phase elements, forming stable or metastable mixed minerals of sulfide minerals and oxide minerals; The porcelain boat with finely ground mineral powder is placed in an atmosphere kiln for roasting. The roasting is carried out in two stages. First, the temperature is raised to 600°C and the oxidation roasting is continued for 1 hour. The air flow rate is controlled at 80mL/min, and then cooled to 400°C with the furnace. , feed HCl gas into the atmosphere kiln for chlorination roasting, control the flow rate of HCl gas to 80mL/min, and continue roasting for 1 hour. Take out the roasted mineral powder and seal it for storage. The SEM and XRD pictures of the roasted ore powder are shown in Figure 4 and Figure 5. It can be seen that the product of the low-grade mixed ore powder after chlorination roasting is mainly composed of nickel chloride, cuprous chloride and The iron oxide composition realizes the selective chlorination of the target nickel and copper elements;

c. the preparation of copper-nickel saturated ionic liquid: place the choline chloride/urea ionic liquid prepared in the step a in the choline chloride/urea ionic liquid prepared in the step b to carry out mixing and Dissolve and stir at 60°C for 10 hours to obtain a choline chloride/urea ionic liquid containing saturated copper and nickel;

d. The composition of the electrolytic cell system: use a polytetrafluoroethylene beaker as an electrolytic cell, use a three-electrode system for electrodeposition, use a platinum disk electrode as a counter electrode, and use a polished and acid-activated length and width of 0.4cm×0.5cm The titanium sheet is used as the working electrode, the platinum electrode is used as the reference electrode, and the above three electrodes are fixed in the polytetrafluoroethylene electrolytic cell, and the copper-nickel saturated ionic liquid prepared in the step c is used as the electrolyte solution, and assembled to form an electrolytic cell. deposition system;

e. Electrodeposition preparation process of copper-nickel alloy: HCP-803 electrochemical workstation, constant temperature temperature controller and electric heating mantle are used to control the electrodeposition process potential of the electrode and the temperature of the electrolyte system in the electrolytic cell for electrodeposition. The electrolytic reaction temperature of the electrolytic cell system formed in the step d is kept at 80°C, and the working electrode potential is controlled at -1.30V by using a three-electrode system, so that the electrodeposition reaction is carried out for 120 minutes; the current density-time curve of the electrodeposition process As shown in Figure 8; due to the relatively high solubility of choline chloride/urea ionic liquid to cuprous chloride and nickel chloride, and the formation of complexes in the process of dissolution, the weakening of cuprous chloride and chlorine The combination of copper-nickel and chlorine in nickel oxide promotes the electrodeposition reaction and improves the reaction efficiency. The whole reaction system only occurs the deposition of metal copper-nickel and chlorine evolution reaction, and the choline chloride/urea ionic liquid does not decompose. , the electrolyte can be recycled many times;

f. Take out the product obtained by electrodeposition in the step e from the electrolytic cell, first clean it with deionized water, and then wash it several times with absolute ethanol until the product obtained by electrodeposition is cleaned, and finally clean the electrodeposited product The obtained product is dried at low temperature, that is, the copper-nickel alloy is obtained on the surface of the metal substrate to be plated, and the direct enrichment and extraction of the copper-nickel alloy from the low-grade mixed ore is realized.

The SEM figure and EDS figure 6 of the copper-nickel alloy product obtained in this embodiment are shown in Figure 7. From the microscopic appearance and energy spectrum analysis of the product, it can be seen that this embodiment can obtain copper-nickel alloy by electrodeposition on the cathode titanium sheet, It fully proves that this example successfully prepared copper-nickel alloy from low-grade copper-nickel mixed ore by using choline chloride/urea ionic liquid by electrodeposition. In this embodiment, by controlling parameters such as temperature, electric potential, and time, the effective control of parameters such as the growth morphology and size of the copper-nickel alloy is realized, and a new method for the production of a new controllable preparation of the copper-nickel alloy is provided. In this embodiment, for a specific low-grade copper-nickel mixed ore, selective oxidation and chlorination are first carried out to form a chlorinated intermediate of copper and nickel and dissolved in an ionic liquid, and finally the copper-nickel alloy is separated by an electrochemical controllable deposition method, and the ions The liquid electrolyte solution can be used repeatedly without producing other by-products, the raw materials and intermediate treatment process are simple, and the reaction conditions are easy to realize. The process of this embodiment has the characteristics of short process, low energy consumption, high efficiency, and low raw material prices.

Embodiment two:

This embodiment is basically the same as Embodiment 1, especially in that:

In this embodiment, referring to Figures 8-10, a method for preparing copper-nickel alloy by electrodeposition of low-grade copper-nickel mixed ore, the steps are as follows:

a. Preparation of ionic liquid electrolyte solution: this step is the same as in Example 1;

B. copper-nickel mixed ore pretreatment: this step is identical with embodiment one;

c. Preparation of copper-nickel saturated ionic liquid: this step is the same as in Example 1;

d. The constitution of electrolytic cell system: this step is identical with embodiment one;

e. Electrodeposition preparation process of copper-nickel alloy: HCP-803 electrochemical workstation, constant temperature temperature controller and electric heating mantle are used to control the electrodeposition process potential of the electrode and the temperature of the electrolyte system in the electrolytic cell for electrodeposition. The electrolytic reaction deposition temperature of the electrolytic cell system formed in the step d is kept at 80°C, and the working electrode potential is controlled at -1.50V by using a three-electrode system, so that the electrodeposition reaction is carried out for 120 minutes; the current density-time of the electrodeposition process The curve is shown in Figure 8;

f. Take out the product obtained by electrodeposition in the step e from the electrolytic cell, first clean it with deionized water, and then wash it several times with absolute ethanol until the product obtained by electrodeposition is cleaned, and finally clean the electrodeposited product The obtained product is dried at low temperature, that is, the copper-nickel alloy is obtained on the surface of the metal substrate to be plated, and the direct enrichment and extraction of the copper-nickel alloy from the low-grade mixed ore is realized.

The SEM figure and EDS figure 9 of the copper-nickel alloy product obtained in this embodiment are shown in Figure 10. From the microscopic appearance and energy spectrum analysis of the product, it can be seen that this embodiment can obtain copper-nickel alloy by electrodeposition on the cathode titanium sheet. It is proved that this example uses choline chloride/urea ionic liquid to successfully prepare copper-nickel alloy from low-grade copper-nickel mixed ore by electrodeposition.

The embodiments of the present invention have been described above in conjunction with the accompanying drawings, but the present invention is not limited to the above-mentioned embodiments, and various changes can also be made according to the purpose of the invention of the present invention. The changes, modifications, substitutions, combinations or simplifications should be equivalent replacement methods, as long as they meet the purpose of the present invention, as long as they do not deviate from the technology of the method for preparing copper-nickel alloys by electrodeposition of low-grade copper-nickel mixed ore of the present invention Principles and inventive concepts all belong to the protection scope of the present invention.

Claims (5)

1. a method for preparing copper-nickel alloy by electrodeposition of low-grade copper-nickel mixed ore, is characterized in that, step is as follows: a. Preparation of ionic liquid electrolyte solution: use choline chloride and urea as the initial raw materials, mix the raw materials according to the molar ratio of the raw material components of choline chloride and urea as 1:2, and keep the temperature at 80~100°C Stir for 10-12 hours until a uniform, colorless and transparent ionic liquid is formed as the electrolyte solution; b. Copper-nickel mixed ore pretreatment: Grind the copper-nickel mixed ore, pass through 200 mesh sieve and then dry, then oxidize and roast the dried ore powder at 600~700℃ in an oxidizing atmosphere After 1~2 hours, the mixed ore powder after oxidation and roasting is chlorinated and roasted. The chlorination roasting is carried out in HCl atmosphere. After the chlorination roasting, the product of the chlorination roasting is cooled to room temperature with the furnace to obtain the chlorination roasting mineral powder; c. Preparation of copper-nickel saturated ionic liquid: place the chlorinated roasted mineral powder pretreated in step b in the ionic liquid prepared in step a for mixing and dissolving, at 60-100°C Stir at constant temperature for 8-10 hours to obtain a copper-nickel-saturated ionic liquid-copper-nickel salt composite electrolyte; d. The composition of the electrolytic cell system: the polytetrafluoroethylene beaker is used as the electrolytic cell, the platinum plate electrode is the counter electrode, the polished and acid-activated metal substrate to be plated is the cathode working electrode, and the platinum electrode is used as the reference electrode. The ionic liquid-copper-nickel salt composite electrolyte prepared in the step c is used as an electrolyte solution to form an electrolytic cell system; e. Electrodeposition preparation process of copper-nickel alloy: keep the electrolytic reaction temperature of the electrolytic cell system formed in the step d at 60~90°C, and then apply a potential of -1.30~-1.50V to the electrolytic cell system Direct current, control the electrodeposition time to 60~120 minutes, and conduct electrodeposition; f. Take out the product obtained by electrodeposition in the step e from the electrolytic cell, first clean it with deionized water, and then wash it several times with absolute ethanol until the product obtained by electrodeposition is cleaned, and finally clean the electrodeposited product The obtained product is dried at low temperature, that is, the copper-nickel alloy is obtained on the surface of the metal substrate to be plated, and the direct enrichment and extraction of the copper-nickel alloy from the low-grade mixed ore is realized. 2. according to claim 1, prepare the method for copper-nickel alloy by electrodeposition of low-grade copper-nickel mixed ore, it is characterized in that: when copper-nickel mixed ore is pretreated in described step b, the oxidation roasting process adopts The atmosphere gas is air. 3. according to the method for preparing copper-nickel alloy by low-grade copper-nickel mixed ore electrodeposition according to claim 1 and 2, it is characterized in that: in the electrodeposition preparation process of described step e copper-nickel alloy, by regulating and controlling electrolytic reaction Any number of process parameters in temperature, potential and electrodeposition time parameters can realize the control of the copper-nickel alloy deposition rate and deposition layer thickness. 4. according to the method for preparing copper-nickel alloy by low-grade copper-nickel mixed ore electrodeposition according to claim 1 and 2, it is characterized in that: when copper-nickel mixed ore is pretreated in described step b, in oxidation roasting process The flow rate of the oxidizing atmosphere is controlled to be close to 80mL/min, and the flow rate of HCl gas is controlled to be close to 80mL/min during the chlorination roasting process. 5. The method for preparing copper-nickel alloy by electrodeposition of low-grade copper-nickel mixed ore according to claim 1 or 2, characterized in that: in the step d, a titanium sheet is used as the cathode of the electrolytic cell system.