Separation and purification process for high-iron indium zinc concentrate

Abstract

The invention relates to the technical field of mineral processing, in particular to a high-iron indium-zinc concentrate separation and purification process which comprises the following steps: pre-treating ores, namely crushing the high-iron indium-zinc concentrate; leaching reaction: feeding the crushed ore into acid liquor for leaching reaction to obtain acid leaching liquor containing indium and zinc; microwave-assisted extraction is conducted, specifically, the acid leaching solution is put into a microwave reactor, microwave extraction is conducted on the acid leaching solution, and a solution with indium ions migrated to an organic phase is obtained after extraction; separation and back extraction: carrying out centrifugal separation and back extraction on the solution to obtain back extraction liquid containing indium; and purifying and recovering, and evaporating, concentrating and crystallizing the back-extractant containing indium to obtain indium. According to the method, through the microwave-assisted extraction technology, the extraction efficiency and selectivity of indium ions are improved, the reaction time is shortened, the microwave heating mode is lower in energy consumption and better in environmental affinity, multiple separation and washing steps are reduced, and the process is simple and convenient.

Description

Technical Field

[0001] The invention relates to the technical field of mineral processing, and in particular to a separation and purification process for high-iron indium zinc concentrate. Background Art

[0002] At present, the separation and purification technology of high-iron indium zinc concentrate mainly relies on traditional methods such as liquid phase extraction, ion exchange and electrolytic deposition. These methods have been widely used in the fields of metallurgy and materials science and have achieved certain results. However, with the gradual improvement of resource utilization and environmental protection requirements, the existing technology has gradually become difficult to use.

[0003] Traditional separation and purification methods have problems such as complex operation, high energy consumption and environmental pollution. Traditional methods usually require multiple separations and washings, which are cumbersome and time-consuming. In addition, many processes need to be carried out under high temperature and high pressure conditions, resulting in huge energy consumption. What is more serious is that traditional methods use a large amount of organic solvents and acid-base reagents, which are prone to produce waste liquids that are harmful to the environment and cause environmental pollution.

[0004] Therefore, there is a need for an efficient and environmentally friendly separation and purification technology for high-iron indium zinc concentrate. Summary of the invention

[0005] The main purpose of the present invention is to provide a separation and purification process for high-iron indium zinc concentrate, aiming to solve the problems of low efficiency and environmental pollution of existing high-iron indium zinc concentrate.

[0006] To achieve the above object, the present invention proposes a separation and purification process for high iron indium zinc concentrate, which comprises the following steps:

[0007] Ore pre-treatment, crushing the ore of high iron indium zinc concentrate;

[0008] Leaching reaction, sending the crushed ore to an acid solution for leaching reaction to obtain an acid leaching solution containing indium and zinc;

[0009] Microwave-assisted extraction: the acid leaching solution is placed in a microwave reactor, and microwave extraction is performed on the acid leaching solution to obtain a solution in which indium ions migrate to an organic phase after extraction;

[0010] Separation and stripping, centrifugation and stripping of the microwave-extracted solution to obtain a stripping solution containing indium;

[0011] Purify and recover, evaporate and concentrate the stripping agent containing indium and crystallize to obtain indium.

[0012] Furthermore, the ore pretreatment step of crushing the ore of the high iron indium zinc concentrate includes:

[0013] Put the high iron indium zinc concentrate into the crushing equipment to crush the high iron indium zinc concentrate into 50-100 μm;

[0014] The crushed high-iron indium zinc concentrate particles are moved to the screening equipment, and the crushed ore particles are screened.

[0015] Furthermore, the leaching reaction, wherein the crushed ore is sent to an acid solution for leaching reaction to obtain an acid leaching solution containing indium and zinc, comprises the following steps:

[0016] The screened ore particles are sent to the acid solution for leaching reaction, and stirring is performed during the leaching reaction to ensure that the solution is evenly mixed;

[0017] The solution is subjected to solid-liquid separation, and the leachate is separated from the solid residue to obtain an acid leachate.

[0018] Furthermore, the microwave-assisted extraction comprises the steps of placing the acid leaching solution in a microwave reactor, subjecting the acid leaching solution to microwave extraction, and obtaining a solution in which indium ions migrate to an organic phase after extraction.

[0019] sending the acid leaching solution to a microwave reactor, and adding an organic extractant to the acid leaching solution;

[0020] The power of the microwave reactor was set to 300-600 W, the reaction temperature was set to 50-70 ° C, and the reaction time was set to 20-40 min;

[0021] Adding alkali solution to the acid leaching solution to adjust the pH value of the solution to between 1.5 and 3.0;

[0022] The microwave reactor is started to perform extraction reaction on the acid leaching solution. During the extraction process, the solution is ensured to be uniform by stirring. After the extraction, a solution in which indium ions migrate to the organic phase is obtained.

[0023] Furthermore, the separation and stripping, the step of centrifuging and stripping the microwave-extracted solution to obtain a stripping solution containing indium, further comprises:

[0024] The microwave-extracted solution is centrifuged to separate an organic phase containing indium and an aqueous phase containing zinc;

[0025] The indium-containing organic phase is mixed with a stripping agent, wherein the volume ratio of the stripping agent to the organic phase is 1:2 to 1:4;

[0026] A stripping reaction is carried out to strip the indium-containing organic phase to obtain a stripping solution containing indium.

[0027] Furthermore, the purification and recovery, evaporation concentration and crystallization of the stripping agent containing indium to obtain indium also includes:

[0028] The stripping solution is evaporated and concentrated to reduce the volume of the stripping solution to 1 / 5 to 1 / 10 of the original volume to obtain a concentrated solution;

[0029] The concentrated solution is crystallized and ethanol is added to precipitate indium crystals;

[0030] Separating the indium crystals from the solution by vacuum filtration and washing the indium crystals with ethanol to remove impurities;

[0031] The washed indium crystals are dried to obtain indium.

[0032] Furthermore, the stripping agent includes one or more of dilute hydrochloric acid, dilute sulfuric acid, nitric acid, and a hydrochloric acid-sulfuric acid mixed solution.

[0033] The present invention improves the extraction efficiency and selectivity of indium ions and shortens the reaction time by using microwave-assisted extraction technology. Compared with traditional heating methods, microwave heating has the advantages of lower energy consumption and better environmental affinity. At the same time, the microwave-assisted extraction technology is used to reduce multiple separation and washing steps, and the process is simple and easy to operate. It is suitable for industrial production and achieves the goals of cost reduction, efficiency improvement and environmental friendliness. DETAILED DESCRIPTION

[0034] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0035] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components in a certain specific posture. If the specific posture changes, the directional indication will also change accordingly.

[0036] In addition, the descriptions of "first", "second", etc. in the present invention are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

[0037] The separation and purification of indium from high-iron indium zinc concentrate relies on liquid phase extraction, ion exchange, electrolytic deposition and other methods in traditional processes. However, these methods have problems such as complex operation, high energy consumption, and environmental pollution. In the present invention, microwave-assisted extraction technology can significantly improve the chemical reaction rate and selectivity through microwave radiation heating, and has the advantages of low energy consumption and environmental protection.

[0038] In the technical solution of the present invention, the stripping agent that can be used includes:

[0039] 0.5-1.0 mol / L of dilute hydrochloric acid, wherein the specific amount of dilute hydrochloric acid used is 1:2 to 1:4 by volume with respect to the organic phase, wherein the dilute hydrochloric acid can effectively destroy the metal complex in the organic phase and return the indium ions from the organic phase to the aqueous phase;

[0040] 0.5-1.0 mol / L dilute sulfuric acid, the specific dosage of dilute hydrochloric acid is 1:2 to 1:4 by volume with the organic phase. Among them, dilute sulfuric acid has excellent stripping effect, but dilute sulfuric acid is highly corrosive, so attention should be paid to operating safety;

[0041] 0.5-1.0 mol / L of dilute nitric acid, the specific amount of dilute hydrochloric acid used is 1:2 to 1:4 by volume with the organic phase, wherein dilute nitric acid has strong oxidizing properties and can effectively strip indium, but it needs to avoid contact with reducing substances during its use;

[0042] 0.5 mol / L hydrochloric acid-sulfuric acid mixed solution, the specific dosage of the hydrochloric acid-sulfuric acid mixed solution is 1:2 to 1:4 in volume ratio with the organic phase, wherein the mixed solution can combine multiple advantages to improve the stripping effect, but requires additional production costs.

[0043] Among them, the present invention includes Examples 1-3 and Comparative Example 1 and Comparative Example 2:

[0044] The following is a comparison of the preparation of Examples 1-3 and Comparative Examples 1 and 2 and the test experiments of indium recovery rate and indium purity. The specific experimental steps are as follows:

[0045] Material preparation:

[0046] Embodiment 1:

[0047] S1. The high iron indium zinc concentrate is crushed, and the ore is crushed to 75 μm through multi-stage crushing, filtering and screening;

[0048] S2, sending the crushed ore particles to a 3 mol / L sulfuric acid solution for leaching reaction, the leaching time is 3 hours, the temperature is 70°C, to obtain an acid leaching solution containing indium and zinc, and then separating the leaching solution from the solid residue by vacuum filtration to obtain a clear acid leaching solution;

[0049] S3, putting the acid leaching solution into a microwave reactor, adding 15% tributyl phosphate as an extractant in the microwave reactor, the volume ratio of the extractant to the leaching solution is 1:8, the microwave reactor parameters are set to a power of 500w, a temperature of 60°C, a reaction time of 30min, and the pH value is adjusted to 2.0;

[0050] S4, centrifuging the microwave-extracted solution at a speed of 4000 rpm for 15 min to separate an indium-containing organic phase and a zinc-containing aqueous phase, and then mixing the indium-containing organic phase with 0.8 mol / L dilute hydrochloric acid at a volume ratio of 1:3 to perform a stripping reaction, stripping at room temperature for 40 min to obtain an indium-containing stripping solution;

[0051] S5. Evaporate and concentrate the stripping agent containing indium to 1 / 6 of the original volume, add an equal volume of ethanol and let stand at 5°C for 18 hours to obtain indium crystals, vacuum filter the indium crystals and wash them with cold ethanol, and dry them in an oven at 50°C after washing to obtain indium.

[0052] Embodiment 2:

[0053] S1. The high iron indium zinc concentrate is crushed and the ore is crushed to 65 μm through multi-stage crushing, filtering and screening;

[0054] S2, sending the crushed ore particles to a 2.5 mol / L sulfuric acid solution for leaching reaction, the leaching time is 2.5 hours, the temperature is 75°C, and an acid leaching solution containing indium and zinc is obtained, and then the leaching solution and the solid residue are separated by vacuum filtration to obtain a clear acid leaching solution;

[0055] S3, putting the acid leaching solution into a microwave reactor, adding 12% tributyl phosphate as an extractant in the microwave reactor, the volume ratio of the extractant to the leaching solution is 1:7, the microwave reactor parameters are set to a power of 450w, a temperature of 65°C, a reaction time of 250min, and adjusting the pH value to 2.5;

[0056] S4, centrifuging the microwave-extracted solution at a speed of 3500 rpm for 15 min to separate an indium-containing organic phase and a zinc-containing aqueous phase, and then mixing the indium-containing organic phase with 0.6 mol / L dilute hydrochloric acid at a volume ratio of 1:2 to perform a stripping reaction, stripping at room temperature for 35 min to obtain an indium-containing stripping solution;

[0057] S5. Evaporate and concentrate the stripping agent containing indium to 1 / 6 of the original volume, add an equal volume of ethanol and let stand at 5°C for 18 hours to obtain indium crystals, vacuum filter the indium crystals and wash them with cold ethanol, and dry them in an oven at 50°C after washing to obtain indium.

[0058] Embodiment 3:

[0059] S1. The high iron indium zinc concentrate is crushed, and the ore is crushed to 80 μm through multi-stage crushing, filtering and screening;

[0060] S2, sending the crushed ore particles to a 4 mol / L sulfuric acid solution for leaching reaction, the leaching time is 4 hours, the temperature is 65°C, and an acid leaching solution containing indium and zinc is obtained, and then the leaching solution and the solid residue are separated by vacuum filtration to obtain a clear acid leaching solution;

[0061] S3, putting the acid leaching solution into a microwave reactor, adding 20% ​​tributyl phosphate as an extractant in the microwave reactor, the volume ratio of the extractant to the leaching solution is 1:10, the microwave reactor parameters are set to a power of 600w, a temperature of 55°C, a reaction time of 40min, and the pH value is adjusted to 1.8;

[0062] S4, centrifuging the microwave-extracted solution at a speed of 5000 rpm for 20 min to separate an indium-containing organic phase and a zinc-containing aqueous phase, and then mixing the indium-containing organic phase with 0.8 mol / L dilute hydrochloric acid at a volume ratio of 1:3 to perform a stripping reaction, stripping at room temperature for 40 min to obtain an indium-containing stripping solution;

[0063] S5. Evaporate and concentrate the stripping agent containing indium to 1 / 6 of the original volume, add an equal volume of ethanol and let stand at 5°C for 18 hours to obtain indium crystals, vacuum filter the indium crystals and wash them with cold ethanol, and dry them in an oven at 50°C after washing to obtain indium.

[0064] Comparative Example 1:

[0065] S1. The high iron indium zinc concentrate is crushed, and the ore is crushed to 75 μm through multi-stage crushing, filtering and screening;

[0066] S2, sending the crushed ore particles to a 3 mol / L sulfuric acid solution for leaching reaction, the leaching time is 3 hours, the temperature is 70°C, to obtain an acid leaching solution containing indium and zinc, and then separating the leaching solution from the solid residue by vacuum filtration to obtain a clear acid leaching solution;

[0067] S3, directly centrifuging the acid leaching solution, the speed of the centrifuge is 4000rpm, the centrifugation time is 15min, separating the indium-containing organic phase and the zinc-containing aqueous phase, and then mixing the indium-containing organic phase with 0.8mol / L dilute hydrochloric acid at a volume ratio of 1:3, performing a stripping reaction, and stripping at room temperature for 40min to obtain an indium-containing stripping solution;

[0068] S4. Evaporate and concentrate the stripping agent containing indium to 1 / 6 of the original volume, add an equal volume of ethanol and let stand at 5°C for 18 hours to obtain indium crystals, vacuum filter the indium crystals and wash them with cold ethanol, and dry them in an oven at 50°C after washing to obtain indium.

[0069] Comparative Example 2:

[0070] S1. The high iron indium zinc concentrate is crushed, and the ore is crushed to 75 μm through multi-stage crushing, filtering and screening;

[0071] S2, sending the crushed ore particles to a 3 mol / L sulfuric acid solution for leaching reaction, the leaching time is 3 hours, the temperature is 70°C, to obtain an acid leaching solution containing indium and zinc, and then separating the leaching solution from the solid residue by vacuum filtration to obtain a clear acid leaching solution;

[0072] S3, putting the acid leaching solution into a microwave reactor, adding 15% tributyl phosphate as an extractant in the microwave reactor, the volume ratio of the extractant to the leaching solution is 1:8, the microwave reactor parameters are set to a power of 500w, a temperature of 60°C, a reaction time of 10min, and the pH value is adjusted to 2.0;

[0073] S4, centrifuging the microwave-extracted solution at a speed of 4000 rpm for 15 min to separate an indium-containing organic phase and a zinc-containing aqueous phase, and then mixing the indium-containing organic phase with 0.8 mol / L dilute hydrochloric acid at a volume ratio of 1:3 to perform a stripping reaction, stripping at room temperature for 40 min to obtain an indium-containing stripping solution;

[0074] S5. Evaporate and concentrate the stripping agent containing indium to 1 / 6 of the original volume, add an equal volume of ethanol and let stand at 5°C for 18 hours to obtain indium crystals, vacuum filter the indium crystals and wash them with cold ethanol, and dry them in an oven at 50°C after washing to obtain indium.

[0075] Indium recovery rate and indium purity detection experiment:

[0076] The materials of Examples 1-3 and Comparative Examples 1 and 2 were selected as samples to test the indium recovery rate and indium purity. The specific experimental steps are as follows:

[0077] (I) Indium recovery rate test

[0078] step:

[0079] S1. Weigh 1g of indium crystals;

[0080] S2. Dissolve the indium crystals in 10 ml of 1 mol / L dilute hydrochloric acid and stir until the indium crystals are completely dissolved;

[0081] S3, dilute the dissolved sample solution to 100 ml;

[0082] S4. Determine the concentration (mg / L) of indium in the solution using an inductively coupled plasma mass spectrometer (ICP-MS);

[0083] S5. Calculate the actual total amount of indium based on the measured indium concentration, and convert it into an indium recovery rate, wherein the calculation formula for the indium recovery rate is (actual total amount of indium / theoretical total amount of indium)*100%.

[0084] (II) Indium purity test

[0085] step:

[0086] S1. Weigh 1g of indium crystals;

[0087] S2. Dissolve the indium crystals in 10 ml of 1 mol / L dilute hydrochloric acid and stir until the indium crystals are completely dissolved;

[0088] S3, dilute the dissolved sample solution to 100 ml;

[0089] S4. Using an inductively coupled plasma mass spectrometer (ICP-MS) to determine the concentration of indium (mg / L) and the concentration of other impurity metals (mg / L) in the solution;

[0090] S5. Calculate the indium purity according to the purity formula, wherein indium purity = (indium concentration / total metal concentration)*100%.

[0091] Table 1 Indium recovery rate and indium purity test data

[0092]

[0093] Experimental conclusion:

[0094] Through the experimental data of the above three groups of embodiments and two groups of control embodiments, it can be seen that the microwave-assisted extraction process adopted in the present invention has a higher indium recovery rate and purity, while significantly reducing energy consumption, which proves the effectiveness and feasibility of the microwave-assisted extraction process in the separation and purification of high-iron indium zinc concentrate.

[0095] In combination with all the above embodiments, the present invention improves the extraction efficiency and selectivity of indium ions and shortens the reaction time through microwave-assisted extraction technology. Compared with traditional heating methods, microwave heating has the advantages of lower energy consumption and better environmental affinity. At the same time, microwave-assisted extraction technology is used to reduce multiple separation and washing steps, the process is simple, the operation is convenient, and it is suitable for industrial production, achieving the goals of cost reduction, efficiency improvement, and environmental friendliness.

[0096] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the present invention specification under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A process for separating and purifying high iron indium zinc concentrate, characterized in that: The following steps are involved: Ore pre-treatment, crushing the ore of high iron indium zinc concentrate; Leaching reaction, sending the crushed ore to an acid solution for leaching reaction to obtain an acid leaching solution containing indium and zinc; Microwave-assisted extraction, the acid leaching solution is placed in a microwave reactor, and the acid leaching solution is subjected to microwave extraction to obtain a solution in which indium ions migrate to an organic phase after extraction; Separation and stripping, centrifugation and stripping of the microwave-extracted solution to obtain a stripping solution containing indium; Purify and recover, evaporate and concentrate the stripping agent containing indium and crystallize to obtain indium.

2. The high iron indium zinc concentrate separation and purification process according to claim 1, characterized in that: The ore pretreatment step of crushing the ore of high iron indium zinc concentrate includes: Put the high iron indium zinc concentrate into the crushing equipment to crush the high iron indium zinc concentrate into 50-100 μm; The crushed high-iron indium zinc concentrate particles are moved to the screening equipment, and the crushed ore particles are screened.

3. The high iron indium zinc concentrate separation and purification process according to claim 1, characterized in that: The leaching reaction, in which the crushed ore is sent to an acid solution for leaching reaction to obtain an acid leaching solution containing indium and zinc, comprises the following steps: The screened ore particles are sent to the acid solution for leaching reaction, and stirring is performed during the leaching reaction to ensure that the solution is evenly mixed; The solution is subjected to solid-liquid separation, and the leachate is separated from the solid residue to obtain an acid leachate.

4. The high iron indium zinc concentrate separation and purification process according to claim 1, characterized in that: The microwave-assisted extraction comprises the steps of placing the acid leaching solution in a microwave reactor, subjecting the acid leaching solution to microwave extraction, and obtaining a solution in which indium ions migrate to an organic phase after extraction. sending the acid leaching solution to a microwave reactor, and adding an organic extractant to the acid leaching solution; The power of the microwave reactor was set to 300-600 W, the reaction temperature was set to 50-70 ° C, and the reaction time was set to 20-40 min; Adding alkali solution to the acid leaching solution to adjust the pH value of the solution to between 1.5 and 3.0; The microwave reactor is started to perform extraction reaction on the acid leaching solution. During the extraction process, the solution is ensured to be uniform by stirring. After the extraction, a solution in which indium ions migrate to the organic phase is obtained.

5. The high iron indium zinc concentrate separation and purification process according to claim 1, characterized in that: The separation and stripping step of centrifuging and stripping the microwave-extracted solution to obtain a stripping solution containing indium also includes: The microwave-extracted solution is centrifuged to separate an organic phase containing indium and an aqueous phase containing zinc; The indium-containing organic phase is mixed with a stripping agent, wherein the volume ratio of the stripping agent to the organic phase is 1:2 to 1:4; A stripping reaction is carried out to strip the indium-containing organic phase to obtain a stripping solution containing indium.

6. The high iron indium zinc concentrate separation and purification process as claimed in claim 5, characterized in that: The purification and recovery step of evaporating, concentrating and crystallizing the stripping agent containing indium to obtain indium also includes: The stripping solution is evaporated and concentrated to reduce the volume of the stripping solution to 1 / 5 to 1 / 10 of the original volume to obtain a concentrated solution; The concentrated solution is crystallized and ethanol is added to precipitate indium crystals; Separating the indium crystals from the solution by vacuum filtration and washing the indium crystals with ethanol to remove impurities; The washed indium crystals are dried to obtain indium.

7. The high iron indium zinc concentrate separation and purification process according to claim 1, characterized in that: The stripping agent includes one or more of dilute hydrochloric acid, dilute sulfuric acid, nitric acid, and a hydrochloric acid-sulfuric acid mixed solution.

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