Method for removing copper from bismuth oxide ore through rough smelting by using bismuth sulfide ore

Abstract

The invention belongs to the technical field of non-ferrous metallurgy, and particularly discloses a method for removing copper from bismuth oxide ore through rough smelting of bismuth sulfide ore, which comprises the following steps of: proportioning the bismuth oxide ore, sodium carbonate and pulverized coal to obtain a rough smelting material, smelting the proportioned rough smelting material, adding the bismuth sulfide ore in batches from a feeding port after the rough smelting material is completely melted and reacted, and smelting the bismuth sulfide ore in batches to remove copper from the bismuth sulfide ore. The slag rake is immediately used for stirring for 3-15 minutes after the bismuth sulfide ore is added every time, the copper content in a reactant is detected after stirring is completed, and when the copper content in the reactant is smaller than 0.5%, discharging operation is conducted to obtain slag and crude bismuth, in this way, no new impurities are introduced during crude smelting of the bismuth oxide ore, the copper content of the produced crude bismuth is low, the bismuth content of the slag is low, and the direct recovery rate of the bismuth is high. Compared with a copper removal and slag making process by adding fluorite, silica, pyrite and other high-melting-point reagents, the method has the characteristics that furnace knotting is not easy to form, and the furnace condition is stable.

Description

Technical Field

[0001] The invention belongs to the technical field of nonferrous metal metallurgy, and in particular relates to a method for using bismuth sulfide ore for rough refining and copper removal of bismuth oxide ore. Background Art

[0002] With the shortage of bismuth ore resources, the raw materials of many domestic bismuth smelters mainly come from copper and lead smelting by-products, such as lead-tin anode mud, copper converter soot, blast furnace dust, etc. The sources are wide, the composition is complex, and the bismuth grade varies. There are two main processing processes for these bismuth-containing materials:

[0003] One is to directly obtain crude bismuth by pyrometallurgical refining, and then obtain refined bismuth by pyrometallurgical refining. For example, the application No. 200910311608.5 discloses a method for extracting crude bismuth from low-grade oxychloride bismuth slag, which is a mixture of low-grade oxychloride bismuth slag produced by comprehensive recovery of anode mud from lead electrolytic refining, coke, soda ash, and pyrite, and is smelted in a converter to produce crude bismuth, alkali slag, copper guns, and smoke. The crude bismuth is sent to pyrometallurgical refining to obtain refined bismuth, the alkali slag is sent to recover lead, the copper guns are sent to recover copper, and the smoke is returned to the converter for smelting. Although the comprehensive recovery rate of metals such as bismuth, copper, and lead is high, oxychloride bismuth will decompose into bismuth chloride at high temperatures. Volatilization, low bismuth recovery rate; for example, application No. 201811246551.0 discloses "A method for recovering refined bismuth and refined copper from high-copper bismuth slag", in which the high-copper bismuth slag produced after oxidative refining of precious lead is mixed with coke, soda ash, borax, pyrite, fluorite and silica in proportion for matte smelting. This method adds pyrite to remove copper, so the crude bismuth obtained has a low copper content, but the raw materials used in the process are complex, and the addition of high-melting-point reagents such as pyrite, fluorite and silica easily causes increased furnace stagnation, unstable furnace conditions, high bismuth content in the slag, and low bismuth recovery rate.

[0004] The second is to pre-treat the impurities by wet method to form high-grade bismuth oxide, and then use fire method to obtain crude bismuth, and then use fire method to obtain refined bismuth. For example, the application number 201610271877.3 discloses the "Method for Refining Bismuth from Bismuth Oxide Slag", which reduces and smelts the impurities-free bismuth oxide slag with a reducing agent to obtain crude bismuth, and then removes copper from the crude bismuth by melting, removes lead by chlorine gas once, removes silver by vacuum distillation, removes lead by chlorine gas twice, removes chlorine by high temperature refining, and removes tellurium by adding caustic soda to finally obtain refined bismuth. The crude bismuth obtained by this method contains up to 40-50% copper. When refining and removing copper, the copper removal slag will take away a large amount of bismuth, the direct yield of bismuth is low, and vacuum distillation equipment needs to be introduced, and the production cost is high.

[0005] Regardless of the treatment process, during the pyrometallurgical refining process, copper elements are enriched in crude bismuth and need to be removed by adding sulfur or smelting during bismuth refining. For example, application No. 201410744143.3 discloses a method for efficient copper removal in bismuth pot refining of crude bismuth. During bismuth refining, sawdust mixed with sulfur is used to remove copper. However, sulfur removal of copper has problems such as low sulfur utilization rate and poor working environment. In addition, due to the high bismuth content in the refining copper removal slag, it cannot be returned to the copper and lead smelting system, and can only be returned to the bismuth refining system as return slag, resulting in an ineffective cycle of bismuth and copper, so that bismuth cannot be effectively recovered. Therefore, we need to propose a method for using bismuth sulfide ore for the rough refining of bismuth oxide ore to remove copper to solve the above-mentioned problems, so that it can effectively improve the recovery rate of bismuth. Summary of the invention

[0006] The object of the present invention is to provide a method for using bismuth sulfide ore for crude refining and copper removal of bismuth oxide ore, which will not introduce new impurities, has low crude bismuth copper content, low bismuth content in slag, and high bismuth direct recovery rate, so as to solve the problems raised in the above background technology.

[0007] To achieve the above object, the present invention adopts the following technical solutions:

[0008] A method for using bismuth sulfide ore for rough refining and copper removal of bismuth oxide ore comprises the following steps:

[0009] S1. Mixing bismuth oxide ore, soda ash and coal powder to obtain a crude refined material;

[0010] S2, adding the crude material into the smelting furnace for smelting, and adding bismuth sulfide ore in batches from the feeding port after the melting reaction of the crude material is complete;

[0011] S3, each time after adding bismuth sulfide ore, immediately use a slag rake to stir for 3-15 minutes, and then detect the copper content in the reactant after stirring;

[0012] S4. When the copper content in the reactants is less than 0.5%, the furnace is unloaded to obtain slag and crude bismuth.

[0013] Preferably, in step S1, the soda ash is set to be one of anhydrous sodium carbonate, washing soda and caustic soda.

[0014] Preferably, the coal powder needs to be finely ground using a coal mill before use to obtain dry and finely divided coal powder particles.

[0015] Preferably, the mass ratio of the bismuth oxide ore, soda ash and coal powder used in the batching is 1:0.1-0.125:0.06-0.12. The bismuth oxide ore, soda ash and coal powder are added to a mixing device in proportion and mixed. The mixed material is the crude refined material.

[0016] Preferably, the bismuth oxide ore needs to be further refined by a grinding device before rough refining, and then the ground bismuth oxide ore is subjected to strict screening and grading operations, and finally dried.

[0017] Preferably, in step S2, the bismuth sulfide ore is prepared by sulfiding bismuth oxide ore, the sulfur content of the bismuth sulfide ore is 8%-18%, the moisture content is less than 3%, and the amount of bismuth sulfide ore added each time is 50-150 kg.

[0018] Preferably, the temperature of the smelting furnace when smelting the crude material is 1100°C-1300°C, and the smelting process includes melting, precipitation, slag discharge and bismuth discharge, wherein melting, precipitation, slag discharge and bismuth discharge are completed once in sequence as one cycle, and the total time for completing one cycle is 8-20 hours.

[0019] Preferably, in step S3, the process of detecting the copper content in the reactant is as follows:

[0020] A1. Select a partially molten reactant sample and rapidly cool the reactant sample to form a thin sheet;

[0021] A2. Set the test parameters of the X-ray fluorescence spectrometer; the parameters include voltage, current and detector type;

[0022] A3. Place the slice into an X-ray fluorescence spectrometer and measure according to the set test conditions. Each sample is measured at least three times, and the average of at least three measurement results is selected as the measurement data;

[0023] A4. Apply the measurement data to the calibration curve to convert X-ray intensity into copper content.

[0024] Preferably, in step A4, the specific operation of applying the measurement data to the calibration curve to convert the X-ray intensity into copper content is as follows:

[0025] A41. Prepare at least three standard bismuth samples containing known concentrations of copper;

[0026] A42. Measure the X-ray intensity of each standard sample using an X-ray fluorescence spectrometer;

[0027] A43. Based on the measurement results of the standard sample, draw a graph of the relationship between copper concentration and X-ray intensity;

[0028] A44. Measure the X-ray intensity of the unknown bismuth sample under the same conditions as the standard sample;

[0029] A45. Substitute the measured X-ray intensity value into the calibration curve and calculate the corresponding copper content.

[0030] Preferably, in step S4, when the copper content in the reactant is ≥0.5%, bismuth sulfide ore needs to be added again for reaction until the copper content in the reactant is <0.5%. When the reactant is discharged from the furnace, the smelting furnace is gradually cooled to gradually solidify the crude bismuth and slag, the obtained slag is recovered, and the crude bismuth is refined.

[0031] The method for using bismuth sulfide ore for rough refining and copper removal of bismuth oxide ore proposed in the present invention has the following advantages compared with the prior art:

[0032] The present invention first mixes bismuth oxide ore with soda ash and coal powder, then smelts the mixed crude materials, adds bismuth sulfide ore in batches after the melting reaction is complete, stirs for 3-15 minutes with a slag rake immediately after each addition of bismuth sulfide ore, detects the copper content in the reactant after stirring, and performs a furnace discharge operation when the copper content in the reactant is less than 0.5% to obtain slag and crude bismuth, so that new impurities are not introduced during the rough refining of bismuth oxide ore, the output crude bismuth has a low copper content, the slag has a low bismuth content, and the bismuth direct yield is high. Compared with the copper removal and slag making process of adding high melting point reagents such as fluorite, silica, pyrite, etc., this method has the characteristics of not being easy to form furnace lumps and stable furnace conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 It is a schematic diagram of the process of the present invention;

[0034] Figure 2 It is a flowchart of the copper content detection of the present invention;

[0035] Figure 3 The present invention is a specific operation flow chart of applying the measurement data to the calibration curve to convert the X-ray intensity into copper content. DETAILED DESCRIPTION

[0036] The following will be combined with the accompanying drawings in 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, rather than all the embodiments. The specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0037] The present invention provides Figure 1-3 A method for using bismuth sulfide ore for rough refining and copper removal of bismuth oxide ore, comprising the following steps:

[0038] S1. Mixing bismuth oxide ore, soda ash and coal powder to obtain a crude refined material;

[0039] The soda ash is set to be one of anhydrous sodium carbonate, washing soda and caustic soda. Anhydrous sodium carbonate is a white powder with high solubility and alkalinity. It is soluble in water at room temperature, and its aqueous solution is strongly alkaline with a pH value of about 11.6. Anhydrous sodium carbonate is produced by passing carbon dioxide into a saturated sodium chloride solution and then generating sodium carbonate through a series of reactions; washing soda is a white crystalline powder with hygroscopicity, which gradually absorbs moisture in the air and begins to decompose carbon dioxide at 400°C. Washing soda is made by combining anhydrous sodium carbonate with water. This form of sodium carbonate is more easily soluble in water and is suitable for use as a cleaning agent; caustic soda is a highly corrosive white solid with extremely strong alkalinity and water absorption. It is highly soluble in water and releases a large amount of heat. Caustic soda is mainly produced by electrolyzing brine (saturated sodium chloride solution), a process called chlor-alkali process.

[0040] The pulverized coal needs to be finely ground using a coal mill before use to obtain dry and finely crushed pulverized coal particles. Proper pretreatment of the pulverized coal is not only the basis for achieving its efficient utilization, but also the basis for ensuring the safe operation of the entire combustion system.

[0041] The mass ratio of the bismuth oxide ore, soda ash and coal powder used in the batching is 1:0.1-0.125:0.06-0.12. The bismuth oxide ore, soda ash and coal powder are added into a mixing device in proportion for mixing. The mixed material is the crude refining material. In this process, the soda ash mainly plays the role of reducing the viscosity of the slag and promoting the separation of metallic bismuth from the slag. The coal powder is used as a reducing agent, and its amount needs to ensure sufficient reducing ability to ensure that the bismuth oxide is fully reduced to metallic bismuth.

[0042] Bismuth oxide ore mainly comes from primary bismuth deposits. Under the surface or near-surface environment, due to long-term exposure to water and oxygen, minerals such as bismuth sulfide in the primary bismuth deposits are oxidized to form bismuth oxide ore. The bismuth oxide ore needs to be further refined by grinding equipment before rough refining to improve the reaction efficiency and bismuth recovery rate in the subsequent smelting process. The ground bismuth oxide ore needs to undergo strict screening and grading operations to remove oversized or undersized particles, and finally dried.

[0043] S2, adding the crude material into the smelting furnace for smelting, and adding bismuth sulfide ore in batches from the feeding port after the melting reaction of the crude material is complete;

[0044] The bismuth sulfide ore is prepared by sulfiding bismuth oxide ore. The bismuth sulfide ore has a sulfur content of 8%-18% and a moisture content of less than 3%. The amount of bismuth sulfide ore added each time is 50-150 kg. Adding the bismuth sulfide ore in batches can ensure that the materials added each time can be fully mixed and reacted with the existing materials in the furnace. By using a slag rake for stirring, not only the uniform distribution of the reactants is accelerated, but also a more efficient chemical reaction is promoted, thereby improving the overall smelting efficiency. In addition, batch feeding helps to maintain the stability of the temperature in the furnace. A large amount of one-time feeding may cause a sharp change in the furnace temperature, affecting the smelting effect and the life of the equipment, while batch feeding can make the temperature change more gentle and predictable, thereby protecting the furnace body and reducing energy consumption.

[0045] The temperature of the smelting furnace when smelting the crude material is 1100°C-1300°C. This temperature range can ensure that the bismuth in the bismuth oxide ore is fully reduced, while avoiding energy waste and equipment loss caused by excessively high temperatures. The smelting process includes melting, precipitation, slag discharge and bismuth discharge, wherein melting, precipitation, slag discharge and bismuth discharge are completed once in sequence as a cycle, and the total time for completing a cycle is 8-20 hours. In this cycle, the duration of each stage needs to be precisely controlled to ensure the smooth progress of the smelting process.

[0046] S3, each time after adding bismuth sulfide ore, immediately use a slag rake to stir for 3-15 minutes, and then detect the copper content in the reactant after stirring;

[0047] The process of copper content detection in the reactants is as follows:

[0048] A1. Select a partially molten reactant sample and rapidly cool the reactant sample to form a thin sheet;

[0049] A2. Set the test parameters of the X-ray fluorescence spectrometer; the parameters include voltage, current and detector type;

[0050] A3. Place the slice into an X-ray fluorescence spectrometer and measure according to the set test conditions. Each sample is measured at least three times, and the average of at least three measurement results is selected as the measurement data;

[0051] A4. Apply the measurement data to the calibration curve to convert X-ray intensity into copper content.

[0052] The specific operation of applying the measurement data to the calibration curve to convert X-ray intensity into copper content is as follows:

[0053] A41. Prepare at least three standard bismuth samples containing known concentrations of copper; these standard samples should cover the range of possible copper concentrations in bismuth to ensure the accuracy and wide applicability of subsequent measurements;

[0054] A42. Use an X-ray fluorescence spectrometer to measure the X-ray intensity of each standard sample. This step must be performed under strictly controlled conditions to ensure the consistency and reliability of each measurement.

[0055] A43. Based on the measurement results of the standard sample, draw a graph of the relationship between copper concentration and X-ray intensity; usually this relationship can be obtained by linear or nonlinear regression analysis, depending on the nature and distribution of the data;

[0056] A44. Measure the X-ray intensity of the unknown bismuth sample under the same conditions as the standard sample; ensure that the instrument settings and operating conditions are consistent with those used to measure the standard sample;

[0057] A45. Substitute the measured X-ray intensity value into the calibration curve and calculate the corresponding copper content; this step is usually completed automatically by software, but it is necessary to ensure that the algorithm used is consistent with the method used to establish the calibration curve.

[0058] S4. When the copper content in the reactants is less than 0.5%, the furnace is unloaded to obtain slag and crude bismuth.

[0059] When the copper content in the reactant is ≥0.5%, bismuth sulfide ore needs to be added again for reaction until the copper content in the reactant is <0.5%. When the reactant is discharged from the furnace, the smelting furnace will be gradually cooled to gradually solidify the crude bismuth and slag. The obtained slag is recovered and the crude bismuth is refined.

[0060] According to the method provided above, bismuth oxide ore was selected for actual rough refining and copper removal operation. The bismuth oxide ores were named bismuth oxide ore 1, bismuth oxide ore 2 and bismuth oxide ore 3. The specific operation steps are as follows:

[0061]

[0062]

[0063] It can be seen from the table data that the copper content in the crude bismuth is less than 0.4%, and the direct recovery rate of bismuth is more than 92%. Therefore, the method provided by the present invention can be used to smelt bismuth oxide ore to effectively reduce the copper content in the crude bismuth, thereby improving the recovery rate of bismuth.

[0064] In summary, bismuth oxide ore is first batched with soda ash and coal powder, and then the batched crude materials are smelted. After the melting reaction is complete, bismuth sulfide ore is added in batches, and a slag rake is used to stir for 3-15 minutes immediately after each addition of bismuth sulfide ore. After stirring, the copper content in the reactant is detected, and when the copper content in the reactant is less than 0.5%, the furnace is unloaded to obtain slag and crude bismuth. In this way, new impurities will not be introduced during the rough refining of bismuth oxide ore, and the output crude bismuth copper content is low, the slag contains low bismuth, and the bismuth direct yield is high. Compared with the addition of high melting point reagents such as fluorite, silica, and pyrite for copper removal and slag making, this method has the characteristics of not being easy to form furnace knots and stable furnace conditions.

[0065] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, it is still possible for those skilled in the art to modify the technical solutions described in the aforementioned embodiments or to make equivalent substitutions for some of the technical features therein. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for using bismuth sulfide ore for rough refining and copper removal of bismuth oxide ore, characterized in that: The steps include: S1. Mixing bismuth oxide ore, soda ash and coal powder to obtain a crude refined material; S2, adding the crude material into the smelting furnace for smelting, and adding bismuth sulfide ore in batches from the feeding port after the melting reaction of the crude material is complete; S3, each time after adding bismuth sulfide ore, immediately use a slag rake to stir for 3-15 minutes, and then detect the copper content in the reactant after stirring; S4. When the copper content in the reactants is less than 0.5%, the furnace is unloaded to obtain slag and crude bismuth.

2. The method for rough refining and copper removal of bismuth oxide ore using bismuth sulfide ore according to claim 1, characterized in that: In step S1, the soda ash is set to be one of anhydrous sodium carbonate, washing soda and caustic soda.

3. The method for rough refining and copper removal of bismuth oxide ore using bismuth sulfide ore according to claim 2, characterized in that: The coal powder needs to be finely ground using a coal mill before use to obtain dry and finely divided coal powder particles.

4. The method for rough refining and copper removal of bismuth oxide ore using bismuth sulfide ore according to claim 3, characterized in that: The mass ratio of the bismuth oxide ore, soda ash and coal powder used in the batching process is 1:0.1-0.125:0.06-0.

12. The bismuth oxide ore, soda ash and coal powder are added into a mixing device in proportion and mixed. The mixed material is the crude refined material.

5. The method for rough refining and removing copper from bismuth oxide ore using bismuth sulfide ore according to claim 4, characterized in that: The bismuth oxide ore needs to be further refined by a grinding device before rough refining, and then the ground bismuth oxide ore is subjected to strict screening and grading operations, and finally dried.

6. The method for using bismuth sulfide ore for rough refining and copper removal of bismuth oxide ore according to claim 5, characterized in that: In step S2, the bismuth sulfide ore is prepared by sulfiding bismuth oxide ore, the sulfur content of the bismuth sulfide ore is 8%-18%, the moisture content is less than 3%, and the amount of bismuth sulfide ore added each time is 50-150kg.

7. The method for using bismuth sulfide ore for rough refining and copper removal of bismuth oxide ore according to claim 6, characterized in that: The temperature of the smelting furnace when smelting the crude material is 1100° C.-1300° C., and the smelting process includes melting, precipitation, slag discharge and bismuth discharge, wherein melting, precipitation, slag discharge and bismuth discharge are completed in sequence once as one cycle, and the total time for completing one cycle is 8-20 hours.

8. The method for rough refining and copper removal of bismuth oxide ore using bismuth sulfide ore according to claim 7, characterized in that: In step S3, the process of detecting the copper content in the reactant is as follows: A1. Select a partially molten reactant sample and rapidly cool the reactant sample to form a thin sheet; A2. Set the test parameters of the X-ray fluorescence spectrometer; the parameters include voltage, current and detector type; A3. Place the slice into an X-ray fluorescence spectrometer and measure according to the set test conditions. Each sample is measured at least three times, and the average of at least three measurement results is selected as the measurement data; A4. Apply the measurement data to the calibration curve to convert X-ray intensity into copper content.

9. The method for rough refining and removing copper from bismuth oxide ore using bismuth sulfide ore according to claim 8, characterized in that: In step A4, the specific operation of applying the measurement data to the calibration curve to convert the X-ray intensity into copper content is as follows: A41. Prepare at least three standard bismuth samples containing known concentrations of copper; A42. Measure the X-ray intensity of each standard sample using an X-ray fluorescence spectrometer; A43. Based on the measurement results of the standard sample, draw a graph of the relationship between copper concentration and X-ray intensity; A44. Measure the X-ray intensity of the unknown bismuth sample under the same conditions as the standard sample; A45. Substitute the measured X-ray intensity value into the calibration curve and calculate the corresponding copper content.

10. The method for using bismuth sulfide ore for rough refining and copper removal of bismuth oxide ore according to claim 9, characterized in that: In step S4, when the copper content in the reactant is ≥0.5%, bismuth sulfide ore needs to be added again for reaction until the copper content in the reactant is <0.5%. When the reactant is discharged from the furnace, the smelting furnace is gradually cooled to gradually solidify the crude bismuth and slag. The obtained slag is recovered and the crude bismuth is refined.

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