A method for oxidative desulfurization of zinc sulfide materials

Abstract

The present application provides a method for oxidative desulfurization of zinc sulfide materials, which includes performing a first oxidative desulfurization reaction on a mixed material formed by zinc sulfide materials and fluxes and oxygen-rich gas in the oxidative smelting zone of a furnace chamber to obtain a preliminarily oxidized material and copper matte; performing a second oxidative desulfurization reaction on the preliminarily oxidized material in the oxidative smelting zone to form a high-zinc material and high-cadmium soot; wherein the temperature of the first oxidative desulfurization reaction is t1, and the oxygen-to-material ratio is OM1; the temperature of the second oxidative desulfurization reaction is t2, and the oxygen-to-material ratio is OM2; 50°C ≤ t2 - t1 ≤ 450°C; 50 Nm 3 / t ≤ OM2 - OM1 ≤ 400 Nm 3 / t. In the present application, the zinc sulfide materials do not require complex preparation and treatment, and are directly added to the oxidative smelting zone of a zinc smelting furnace, and the first oxidative desulfurization reaction and the second oxidative desulfurization reaction are sequentially performed, thereby improving the recovery rate of valuable metals in the zinc sulfide materials.

Description

Technical Field

[0001] The present application relates to the field of metal reduction and recovery, and particularly to a method for oxidative desulfurization of zinc sulfide materials. Background Art

[0002] Pyrometallurgical zinc smelting has the characteristics of processing complex raw materials and simple process, and has been widely applied to the smelting of lead and zinc metals. Among them, pyrometallurgy mainly includes blast furnace, shaft furnace and electric furnace processes. Zinc smelting in blast furnace can only process lead-zinc mixed ores with a certain lead-zinc ratio, and the raw materials must be sintered before entering the furnace. The final slag of blast furnace contains 5%-7% zinc, and the recovery rate of valuable metals such as zinc is low; for shaft furnace zinc smelting, zinc sulfide materials must be subjected to desulfurization and shaping treatments such as roasting and pelletizing before entering the furnace. It has high requirements for raw material composition and complex preparation process. The final slag contains 5%-10% zinc, and the recovery rates of valuable metals such as zinc, copper, gold and silver are all relatively low; for electric furnace zinc smelting, zinc sulfide materials need to be subjected to desulfurization treatments such as roasting before entering the furnace, and the atmosphere and temperature in the furnace need to be controlled during the smelting process after entering the furnace. The final slag contains 3%-6% zinc, and the recovery rate of valuable metals is relatively low. Summary of the Invention

[0003] The present application aims to solve at least one of the technical problems in the related art to some extent. The present application provides a method for oxidative desulfurization of zinc sulfide materials. The zinc sulfide materials do not require complex preparation and treatment, and are directly added to the oxidative smelting zone of a zinc smelting furnace, and are successively subjected to a first oxidative desulfurization reaction and a second oxidative desulfurization reaction, so as to improve the recovery rate of valuable metals in the zinc sulfide materials.

[0004] According to an embodiment of the present application, a method for oxidative desulfurization of zinc sulfide materials is provided, including the following steps:

[0005] A mixed material formed by zinc sulfide materials and fluxes undergoes a first oxidative desulfurization reaction with oxygen-rich gas in the oxidative smelting zone of the furnace cavity to obtain a preliminarily oxidized material and copper matte materials;

[0006] The preliminarily oxidized material undergoes a second oxidative desulfurization reaction in the oxidative smelting zone to form a high-zinc material and high-cadmium soot; wherein the temperature of the first oxidative desulfurization reaction is t1, and the oxygen-to-material ratio is OM1; the temperature of the second oxidative desulfurization reaction is t2, and the oxygen-to-material ratio is OM2; 50°C ≤ t2 - t1 ≤ 450°C; 50 Nm 3 / t ≤ OM2 - OM1 ≤ 400 Nm 3 / t.

[0007] In some embodiments, the temperature of the first oxidative desulfurization reaction is 1100 - 1300°C, and the oxygen-to-material ratio is 100 - 250 Nm 3 / t.

[0008] In some embodiments, the temperature of the second oxidative desulfurization reaction is 1350 - 1550 °C, and the oxygen-to-feed ratio is 300 - 500 Nm 3 / t.

[0009] In some embodiments, the particle size of the mixed material is D, where 0.05 mm ≤ D ≤ 5 mm.

[0010] In some embodiments, the oxygen concentration of the oxygen-enriched gas is 23 - 99.8%, and the pressure in the furnace chamber is 0.2 MPa - 0.5 MPa.

[0011] In some embodiments, the mass ratio of the zinc sulfide material to the flux in the mixed material is 5 - 20:1.

[0012] In some embodiments, the flux includes at least one of quartz sand, quicklime, and limestone.

[0013] In some embodiments, the injection method in the oxidative smelting zone includes single side blowing, single bottom blowing, or a combination of side blowing and bottom blowing.

[0014] In some embodiments, the mass percentage of sulfur element in the preliminary oxidized material obtained in the first oxidative desulfurization reaction is 2% - 5%;

[0015] and / or, based on the zinc sulfide material, by mass percentage, 70% - 80% of the copper element, 80% - 90% of the gold element, and 80% - 90% of the silver element in the zinc sulfide material are enriched in the copper matte material;

[0016] and / or, the mass percentage of copper element in the copper matte material is 10% - 30%.

[0017] In some embodiments, the mass percentage of sulfur element in the high-zinc material is less than 1%;

[0018] and / or, the mass percentage of zinc element in the high-zinc material is 40% - 60%;

[0019] and / or, the mass percentage of cadmium element in the high-cadmium soot is greater than 12%.

[0020] The zinc sulfide material of the present application does not require complicated preparation and processing. The mixed material has a suitable particle size, is fully contacted with the oxygen-rich gas in the oxidation smelting zone of the furnace chamber, and undergoes the first oxidation desulfurization reaction under low temperature and low oxygen potential conditions to obtain a preliminary oxide material and a copper matte material. The copper matte material is discharged from a siphon port set in the oxidation smelting zone; and the preliminary oxide material continues to undergo deep oxidation desulfurization in the oxidation smelting zone under high temperature and high oxygen potential conditions to form a high-zinc material and high-cadmium smoke. The above-mentioned oxidation desulfurization method of the zinc sulfide material does not require complicated preparation and processing of the zinc sulfide material, and can effectively improve the recovery rate of valuable metals in the zinc sulfide material.

[0021] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0023] Figure 1 It is a flow chart of a method for oxidative desulfurization of zinc sulfide material according to one embodiment of the present application. DETAILED DESCRIPTION

[0024] Embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and cannot be construed as limiting the present application. On the contrary, the present application includes all changes, modifications and equivalents that fall within the spirit and connotation of the appended claims.

[0025] The existing hydrometallurgical zinc smelting technology has a long process, complex process, huge investment and high energy consumption. Most importantly, the hydrometallurgical process produces a large amount of leaching slag, iron slag, etc., with an output rate of more than 50%, which are all hazardous wastes and need to be harmlessly treated, which in turn causes a large amount of energy consumption and brings new pollution. The existing pyrometallurgical zinc smelting technology generally has high energy consumption, complex material preparation process, low zinc direct recovery rate and recovery rate, and small single series production capacity, which cannot meet the requirements of modern large-scale industrial production.

[0026] In the related technologies at present, a lead-zinc ore smelting method is mentioned. The lead-zinc ore is melted in an oxidation smelting furnace, and the melt is sent to a power frequency electric heating reduction furnace for reduction. Zinc vapor is condensed by traditional lead rain or zinc rain to obtain crude zinc. Or zinc sulfide materials are melted in an oxygen bottom-blown smelting furnace, and the melt is sent to a side-blown reduction furnace for reduction. Zinc vapor is condensed by traditional lead rain or zinc rain to obtain crude zinc. Zinc sulfide materials are melted in an oxygen bottom-blown smelting furnace, and then cast into blocks and sent to a blast furnace for reduction. Zinc vapor is condensed by traditional lead rain or zinc rain to obtain crude zinc. The above methods have solved many problems existing in hydrometallurgical zinc smelting. However, compared with the existing pyrometallurgical zinc smelting methods, only the problem of complex charging systems has been mainly solved, and there is no obvious improvement in the smelting process and the recovery of valuable metals.

[0027] To solve the problem of low recovery rate of valuable metals, some related technologies mention the use of a blast furnace for smelting. The molten slag needs to be cast and cooled, the charging process is complex, the energy consumption is high, the zinc recovery rate has not been improved compared with traditional pyrometallurgical zinc smelting technologies, and there is room for further improvement in the recovery rate of valuable metal recovery. There are also some related technologies that mention the use of two metallurgical furnaces. The molten slag flows from the bottom-blown furnace into the side-blown furnace, inevitably resulting in heat loss and increasing the flue gas escape points. The side-blown furnace reduction belongs to bath smelting and requires a large amount of oxygen-rich air to be blown in, resulting in a low concentration of zinc vapor, which is more likely to cause secondary oxidation of zinc vapor and reduce the direct zinc recovery rate. The smelting temperature of the side-blown furnace is 1200 - 1250 °C, the zinc content in the slag is relatively high, the direct zinc recovery rate and the recovery rate are low, iron cannot be recovered, and the subsequent flue gas treatment cost is high. There is room for further improvement in the recovery rate of valuable metal recovery. In addition, some related technologies mention the use of two metallurgical furnaces. The molten slag flows from the oxidation smelting furnace into the power frequency electric heating reduction furnace, inevitably resulting in heat loss and increasing the flue gas escape points. The smelting temperature of the power frequency electric heating reduction furnace is limited, which will cause a relatively high zinc content in the slag and a low zinc recovery rate. Iron cannot be recovered. The single-series production capacity of the power frequency electric heating reduction furnace is limited and it is difficult to adapt to large-scale industrial production. There is room for further improvement in the recovery rate of valuable metal recovery.

[0028] Based on this, the technical solution of the embodiment of the present application provides a method for oxidative desulfurization of zinc sulfide materials. The zinc sulfide materials do not require complex charging and treatment, and are directly added to the oxidation smelting area of the zinc smelting furnace, and the first oxidative desulfurization reaction and the second oxidative desulfurization reaction are carried out in sequence to improve the recovery rate of valuable metals in the zinc sulfide materials.

[0029] The "range" disclosed in this application is defined in the form of a lower limit and an upper limit. A given range is defined by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundaries of a particular range. The ranges defined in this way can include or exclude the end values, and can be combined arbitrarily, that is, any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60 - 120 and 80 - 110 are listed for a specific parameter, ranges of 60 - 110 and 80 - 120 are also contemplated. In addition, if the minimum range values 1 and 2 are listed, and if the maximum range values 3, 4, and 5 are listed, then the following ranges are all contemplated: 1 - 3, 1 - 4, 1 - 5, 2 - 3, 2 - 4, and 2 - 5. In this application, unless otherwise specified, the numerical range "a - b" represents an abbreviated representation of any real number combination between a and b, where a and b are both real numbers. For example, the numerical range "0 - 5" means that all real numbers between "0 - 5" are fully listed herein, and "0 - 5" is only an abbreviated representation of these numerical combinations. Additionally, when stating that a certain parameter is an integer ≥ 2, it is equivalent to disclosing that the parameter is, for example, the integers 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0030] In the description of the embodiments of this application, the term "and / or" is merely an association relationship describing associated objects, indicating that three relationships can exist. For example, A and / or B can represent: A exists alone, A and B exist simultaneously, and B exists alone. Additionally, in this document, the character " / " generally indicates that the associated objects before and after are in an "or" relationship.

[0031] To achieve the above object, according to an embodiment of this application, a method for oxidative desulfurization of zinc sulfide material is proposed as Figure 1 , comprising the following steps:

[0032] S1: A mixed material formed by a zinc sulfide material and a flux reacts with an oxygen-rich gas in the oxidative smelting zone of a furnace chamber to undergo a first oxidative desulfurization reaction, obtaining a preliminarily oxidized material and a copper matte material;

[0033] S2: The preliminarily oxidized material undergoes a second oxidative desulfurization reaction in the oxidative smelting zone to form a high-zinc material and high-cadmium dust; wherein the temperature of the first oxidative desulfurization reaction is t1, and the oxygen-to-material ratio is OM1; the temperature of the second oxidative desulfurization reaction is t2, and the oxygen-to-material ratio is OM2; 50°C ≤ t2 - t1 ≤ 450°C; 50 Nm 3 / t ≤ OM2 - OM1 ≤ 400 Nm 3 / t.

[0034] Among them, in S1, a mixed material formed by zinc sulfide material and flux is provided. The zinc sulfide material includes zinc, lead, and sulfur elements, and usually also includes iron, sulfur, calcium, and silicon elements. In addition to the above elements, in some embodiments, the lead-zinc sulfide material may also include other elements, such as oxygen, magnesium, copper, aluminum, cadmium, arsenic, etc. Compared with other elements, the contents of zinc, lead, iron, sulfur, calcium, and silicon elements are relatively high. Exemplarily, the lead-zinc sulfide material includes Zn 10-40 wt.%; Pb 5-30 wt.%; S 10-30 wt.%; Fe 3-15 wt.%; Ca 1-10 wt.%; SiO2 2-10 wt.%. For example, Zn 20-40 wt.%, Pb 10-30 wt.%, S 15-30 wt.%, Fe 4-15 wt.%, Ca 1-5 wt.%, and SiO2 2-6 wt.%. The lead-zinc sulfide material can be natural lead-zinc sulfide minerals or raw materials formed by smelting with relatively high contents of sulfur, lead, and zinc elements. Among them, according to the different elements with the highest content, the lead-zinc sulfide material can be divided into lead concentrate (the highest lead content) and zinc concentrate (the highest zinc content).

[0035] Exemplarily, the main elements and component contents of the lead concentrate are Pb 36.82 wt.%, Zn 16.25 wt.%, S 13.86 wt.%, Fe 3.84 wt.%, Cu 0.40 wt.%, CaO 3.08 wt.%, and SiO2 5.16 wt.%.

[0036] Exemplarily, the main elements or component contents of the zinc concentrate are Zn 43.49 wt.%, Pb 3.09 wt.%, S 28.61 wt.%, Fe 11.10 wt.%, Cu 0.74 wt.%, Cd 0.39 wt.%, CaO 0.82 wt.%, and SiO2 6.12 wt.%.

[0037] In this application, the mixed material formed by the zinc sulfide material and the flux in a mass ratio of 5-20:1 is in the form of fine particles. The flux includes at least one of quartz sand, quicklime, and limestone. Its particle size does not need to be precisely controlled, only less than or equal to 5 mm and greater than or equal to 0.05 mm; in other words, the particle size of the mixed material is D, where 0.05 mm ≤ D ≤ 5 mm; for example, D is 0.05 mm, 0.1 mm, 0.5 mm, 1 mm, 2 mm, 3 mm, 4 mm, 5 mm, etc. The particle size of the mixed material is reasonable. When the particle size of the mixed material is too large, such as greater than 5 mm, the specific surface area of the mixed material decreases, and its contact area with the oxygen-rich gas decreases, resulting in a decrease in the reaction rate.

[0038] Exemplarily, the mass ratio of zinc sulfide material to flux is (5, 6, 7, 8, 10, 12, 14, 15, 17, 18, 19, 20):1. When the mass ratio value of zinc sulfide material to flux is relatively large, such as greater than 20, the melting point of the resulting final high-zinc material is high and the viscosity of the slag is large, which is not conducive to smelting; when the mass ratio value of zinc sulfide material to flux is relatively small, such as less than 5, the amount of flux is too high, resulting in increased smelting energy consumption and increased production costs.

[0039] Among them, the oxygen concentration in the oxygen-rich gas is 23 - 99.8%, and the pressure in the furnace cavity is 0.2 MPa - 0.5 MPa; the oxygen-rich gas can be pure oxygen or a mixed gas of oxygen and other gases (such as nitrogen). In this embodiment, the oxygen concentration in the oxygen-rich gas is 23 - 99.8%. The relatively high oxygen concentration in the oxygen-rich gas can provide sufficient oxygen, enabling the mixed materials to react fully.

[0040] The mixed materials and the oxygen-rich gas enter the oxidative smelting zone through the injection method in the oxidative smelting zone for mixing and reaction. The injection method in the oxidative smelting zone includes single side blowing, single bottom blowing, or a mixture of side blowing and bottom blowing. The mixed materials undergo the first oxidative desulfurization reaction in the oxidative smelting zone to obtain the preliminary oxidized material and copper matte material. The mass percentage of sulfur element in the preliminary oxidized material is 2% - 5%; based on the zinc sulfide material, by mass percentage, 70% - 80% of copper element, 80% - 90% of gold element, and 80% - 90% of silver element in the zinc sulfide material are enriched in the copper matte material for recovery; based on the copper matte material, the mass percentage of copper element in the copper matte material is 10% - 30%.

[0041] Among them, in S2, the preliminary oxidized material undergoes a second oxidative desulfurization reaction in the oxidative smelting zone to form a high-zinc material and high-cadmium dust. The mass percentage of sulfur element in the high-zinc material is less than 1%; the mass percentage of zinc element in the high-zinc material is 40% - 60%; the mass percentage of cadmium element in the high-cadmium dust is greater than 12%. The temperature of the first oxidative desulfurization reaction is t1, and the oxygen-to-material ratio is OM1; the temperature of the second oxidative desulfurization reaction is t2, and the oxygen-to-material ratio is OM2; 50°C ≤ t2 - t1 ≤ 450°C; 50 Nm 3 / t ≤ OM2 - OM1 ≤ 400 Nm 3 / t.

[0042] For example, the difference value of t2 - t1 is 50°C, 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, etc.; the difference value of OM2 - OM1 is 50 Nm 3 / t, 100 Nm 3 / t, 150 Nm 3 / t, 200 Nm 3 / t, 250 Nm3 / t, 300 Nm 3 / t, 350 Nm 3 / t, 400 Nm 3 / t, etc. For example, the temperature of the first oxidative desulfurization reaction is 1100 - 1300 °C, and the oxygen-to-feed ratio is 100 - 250 Nm 3 / t. In some embodiments, the temperature of the first oxidative desulfurization reaction is 1100 °C, 1200 °C, 1300 °C, etc.; meanwhile, its oxygen-to-feed ratio is 100 Nm 3 / t, 150 Nm 3 / t, 200 Nm 3 / t, 250 Nm 3 / t, etc.; when the temperature of the first oxidative desulfurization reaction is lower than 1100 °C, the slag is more viscous, which is not conducive to the oxidative desulfurization reaction; when the temperature of the first oxidative desulfurization reaction is higher than 1300 °C, the oxidative desulfurization reaction proceeds too fast, which is not conducive to the formation of matte materials; when the oxygen-to-feed ratio of the first oxidative desulfurization reaction is lower than 100 Nm 3 / t, the oxygen content is too low, which will cause the sulfur content of the preliminary oxidized materials to be too high and is not conducive to the second desulfurization reaction; when the oxygen-to-feed ratio of the first oxidative desulfurization reaction is higher than 250 Nm 3 / t, the first oxidative desulfurization reaction is too fast, which is not conducive to the formation of matte materials.

[0043] In some embodiments, the temperature of the second oxidative desulfurization reaction is 1350 - 1550 °C, and the oxygen-to-feed ratio is 300 - 500 Nm 3 / t. The exemplary temperature of the second oxidative desulfurization reaction is 1350 °C, 1400 °C, 1450 °C, 1550 °C, etc.; meanwhile, its oxygen-to-feed ratio is 300 Nm 3 / t, 350 Nm 3 / t, 400 Nm 3 / t, 500 Nm 3 / t, etc.; when the temperature of the second oxidative desulfurization reaction is lower than 1350 °C, the slag is more viscous, which is not conducive to the second deep oxidative desulfurization reaction; when the temperature of the second oxidative desulfurization reaction is higher than 1550 °C, the molten bath temperature is too high, which affects the life of the furnace body of the zinc smelting furnace and the lance for injection in the oxidative smelting area; when the oxygen-to-feed ratio of the second oxidative desulfurization reaction is lower than 300 Nm 3 / t, the oxygen is insufficient, which is not conducive to the second deep oxidative desulfurization reaction; when the oxygen-to-feed ratio of the second oxidative desulfurization reaction is higher than 500 Nm 3 / t, it exceeds the oxygen amount required for desulfurization, resulting in waste.

[0044] The zinc sulfide material of the present application does not require complex preparation and treatment. The mixed material formed by the zinc sulfide material and the flux has a suitable particle size. The mixed material and the oxygen-enriched gas are in full contact in the oxidation smelting area of the furnace cavity and undergo the first oxidation desulfurization reaction under low-temperature and low-oxygen potential conditions. By controlling the oxygen-to-feed ratio, a low-temperature and low-oxygen potential atmosphere is created. The limited oxygen preferentially reacts with the zinc sulfide with high content and high activity, removing a part of sulfur. The copper sulfide in the mixed material forms copper matte, and finally, a preliminarily zinc-containing oxidized material, i.e., a preliminarily oxidized material (there is still a part of sulfur not removed), and copper matte material are obtained. The copper matte material is discharged from the siphon port set in the oxidation smelting area. That is, during the first oxidation desulfurization reaction, under this oxygen-to-feed ratio condition, it is ensured that the oxygen-enriched gas can provide an oxygen-enriched environment for the mixed gas to promote the oxidation desulfurization reaction, and at the same time, at this reaction temperature, the mixed material can reach a better reaction state during the first oxidation desulfurization reaction.

[0045] The preliminarily oxidized material continues to undergo further deep oxidation desulfurization in the oxidation smelting area under high-temperature and high-oxygen potential conditions to form a high-zinc material and high-cadmium dust. When the second oxidation desulfurization reaction occurs, 50°C ≤ t2 - t1 ≤ 450°C, where t1 is the temperature of the first oxidation desulfurization reaction and t2 is the temperature of the second oxidation desulfurization reaction. At this reaction temperature, the sulfide concentrate can undergo deep oxidation desulfurization well to form a high-zinc material and high-cadmium dust. The oxidation desulfurization method of the zinc sulfide material provided by the present application does not require complex preparation and treatment of the zinc sulfide material and can effectively improve the recovery rate of valuable metals in the zinc sulfide material.

[0046] To facilitate further understanding of the present application, the following further describes the solution of the present application in combination with embodiments. Those skilled in the art will understand that only some examples are described in the present application, and any other suitable specific examples are within the scope of the present application.

[0047] Example 1

[0048] This example provides an oxidation desulfurization method for zinc sulfide material, in which zinc concentrate is used as the zinc sulfide material for development, and its specific operating parameters are as follows: The zinc concentrate does not require complex preparation and is mixed with quartz sand in a mass ratio of 20:1 to obtain a mixed material with a particle size of 0.05 mm. The mixed material is added to the oxidation smelting area of a short-process pyrometallurgical zinc smelting furnace; the mixed material undergoes the first oxidation desulfurization reaction in the oxidation smelting area at 1100°C and an oxygen-to-feed ratio of 100 Nm 3 / t condition. During this process, copper matte material and a preliminarily oxidized material are formed. The mass percentage of S element in the preliminarily oxidized material is 5%, and the mass percentage of Cu element in the copper matte material is 10%. The copper matte material deposits at the bottom of the molten pool in the hearth and is discharged from the siphon port set in the oxidation smelting area; the temperature of the oxidation smelting area is increased to 1350°C and the oxygen-to-feed ratio is increased to 300 Nm 3 / t to further desulfurize the slag, forming high-zinc materials and high-cadmium fumes. The high-zinc materials contain 0.9% S element and 40% Zn element by mass percentage, and the high-cadmium fumes contain 13% Cd element.

[0049] Example 2

[0050] This example provides a method for oxidative desulfurization of zinc sulfide materials, which uses zinc concentrate as the zinc sulfide material for implementation. The specific operating parameters are as follows: The zinc concentrate does not require complex preparation. After being mixed with flux quartz sand at a mass ratio of 10:1, a mixed material with a particle size of 0.05 mm is obtained. The mixed material is added to the oxidative smelting zone of a short-process pyrometallurgical zinc smelting furnace. The mixed material undergoes the first oxidative desulfurization reaction in the oxidative smelting zone at 1200 °C and an oxygen-to-feed ratio of 200 Nm 3 / t. In this process, matte materials and preliminarily oxidized materials are formed. The mass percentage of S element in the preliminarily oxidized materials is 3%, and the mass percentage of Cu element in the matte materials is 20%. The matte materials are deposited at the bottom hearth of the molten pool and discharged through the siphon port set in the oxidative smelting zone. The temperature of the oxidative smelting zone is increased to 1450 °C and the oxygen-to-feed ratio is increased to 400 Nm 3 / t to further desulfurize the slag, forming high-zinc materials and high-cadmium fumes. The high-zinc materials contain 0.5% S element and 50% Zn element by mass percentage, and the high-cadmium fumes contain 15% Cd element.

[0051] Example 3

[0052] This example provides a method for oxidative desulfurization of zinc sulfide materials, which uses zinc concentrate as the zinc sulfide material for implementation. The specific operating parameters are as follows: The zinc concentrate does not require complex preparation and is mixed with quartz sand at a mass ratio of 5:1 to obtain a mixed material with a particle size of 0.05 mm. The mixed material is added to the oxidative smelting zone of a short-process pyrometallurgical zinc smelting furnace. The mixed material undergoes the first oxidative desulfurization reaction in the oxidative smelting zone at 1300 °C and an oxygen-to-feed ratio of 250 Nm 3 / t. In this process, matte materials and preliminarily oxidized materials are formed. The mass percentage of S element in the preliminarily oxidized materials is 2%, and the mass percentage of Cu element in the matte materials is 30%. The matte materials are deposited at the bottom hearth of the molten pool and discharged through the siphon port set in the oxidative smelting zone. The temperature of the oxidative smelting zone is increased to 1550 °C and the oxygen-to-feed ratio is increased to 500 Nm 3 / t to further desulfurize the slag, forming high-zinc materials and high-cadmium fumes. The mass percentage of S element in the high-zinc materials is 0.3% and the mass percentage of Zn element is 60% by mass percentage, and the mass percentage of Cd element in the high-cadmium fumes is 20%.

[0053] Comparative Example 1

[0054] The conventional short-process zinc smelting device and method are used, and zinc concentrate is used as the zinc sulfide material. The specific operating parameters are as follows: zinc concentrate (containing Zn: 50%) and slag-making agent (FeO, SiO2 and CaO) are directly added from the feeding port set in the Bref furnace smelting zone, oxygen-enriched air is sprayed into the Bref furnace from the side of the Bref furnace smelting zone, and then the zinc concentrate and the oxygen-enriched air are oxidized and smelted to obtain flue gas and high-zinc slag. The oxygen concentration in the oxygen-enriched air is 60%, and the smelting temperature in the Bref furnace smelting zone is 1300°C. The method in this embodiment cannot realize the recovery of precious metals from copper matte produced in the side blowing stage.

[0055] Comparative Example 2

[0056] This comparative example is different from Example 3 in the following aspects: the mixed material is oxidized and smelted in the smelting zone at 1050°C, the oxygen-to-material ratio is 300 Nm 3 / t conditions for the first oxidation desulfurization reaction, this process forms copper matte material and preliminary oxide material, the mass percentage of S element in the preliminary oxide material is less than 1%, but the copper matte material is dispersed in the preliminary oxide material, and the copper matte material cannot be deposited in the furnace at the bottom of the molten pool to separate from the slag, and cannot be discharged from the siphon port set in the oxidation smelting zone, and the precious metal cannot be recovered; then the oxidation smelting zone temperature is increased to 1075℃ and the oxygen-to-material ratio is increased to 325Nm 3 / t, to further desulfurize the slag. At this time, the viscosity of the slag is very high and smelting cannot proceed normally.

[0057] Comparative Example 3

[0058] This comparative example is different from Example 3 in the following aspects: the mixed material is oxidized and smelted in the 1000°C smelting zone, and the oxygen-to-material ratio is 50 Nm 3 / t conditions for the first oxidation desulfurization reaction, this process forms a large amount of zinc sulfide and copper sulfur mixture, and a small amount of preliminary oxide material, and the preliminary oxide material is all mixed and dispersed in the mixture of zinc sulfide and copper sulfur. A large amount of zinc sulfide and copper sulfur mixture is deposited on the furnace at the bottom of the molten pool and discharged from the siphon port set in the oxidation smelting zone. Not only is it difficult to recover precious metals, but most of the zinc element is lost; increase the temperature of the oxidation smelting zone to 1500℃ and increase the oxygen-to-material ratio to 500Nm 3 / t, to further desulfurize the slag. At this point, due to the large loss of zinc element caused by the first stage of oxidative desulfurization, it is meaningless to continue smelting in this process.

[0059] Therefore, the present application proposes a method for oxidative desulfurization of zinc sulfide materials. The zinc sulfide materials do not require complicated preparation and processing, and are directly added to the oxidative smelting zone of the zinc smelting furnace, and the first oxidative desulfurization reaction and the second oxidative desulfurization reaction are carried out in sequence to improve the recovery rate of valuable metals in the zinc sulfide materials.

[0060] In the description of this specification, the descriptions referring to terms such as "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials, or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of this application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0061] Although the embodiments of this application have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting this application. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

Claims

1. A method for oxidizing and desulfurizing zinc sulfide materials, characterized in that, It includes the following steps: The mixed material formed by zinc sulfide material and flux undergoes the first oxidative desulfurization reaction with oxygen-rich gas in the oxidation smelting zone of the furnace cavity to obtain the preliminarily oxidized material and copper matte material; Carry out a second oxidative desulfurization reaction on the preliminary oxidized material in the oxidative smelting zone to form a high-zinc material and high-cadmium soot; wherein the temperature of the first oxidative desulfurization reaction is t1, and the oxygen-to-material ratio is OM1; the temperature of the second oxidative desulfurization reaction is t2, and the oxygen-to-material ratio is OM2; 50°C ≤ t2 - t1 ≤ 450°C; 50 Nm 3 / t ≤ OM2 - OM1 ≤ 400 Nm 3 / t; wherein the temperature of the first oxidative desulfurization reaction is 1100 - 1300°C, and the oxygen-to-material ratio is 100 - 250 Nm 3 / t.

2. The method according to claim 1, wherein The temperature of the second oxidative desulfurization reaction is 1350 - 1550 °C, and the oxygen-to-feed ratio is 300 - 500 Nm 3 / t.

3. The method according to claim 2, wherein The particle size of the mixed material is D, where 0.05 mm ≤ D ≤ 5 mm.

4. The method according to claim 2, wherein The oxygen concentration in the oxygen-rich gas is 23 - 99.8%, and the pressure in the furnace cavity is 0.2 MPa - 0.5 MPa.

5. The method according to claim 2, wherein The mass ratio of the zinc sulfide material to the flux in the mixed material is 5 - 20:

1.

6. The method according to claim 2, wherein The flux includes at least one of quartz sand, quicklime, and limestone.

7. The method according to claim 2, wherein The injection method in the oxidation smelting zone includes single side blowing, single bottom blowing, or a combination of side blowing and bottom blowing.

8. The method according to claim 2, wherein In the first oxidative desulfurization reaction, the mass percentage of sulfur element in the obtained preliminarily oxidized material is 2% - 5%; And / or, based on the zinc sulfide material, by mass percentage, 70% - 80% of the copper element, 80% - 90% of the gold element, and 80% - 90% of the silver element in the zinc sulfide material are enriched in the copper matte material; And / or, the mass percentage of copper element in the copper matte material is 10% - 30%.

9. The method according to claim 2, characterized in that The mass percentage of sulfur element in the high-zinc material is less than 1%; And / or, the mass percentage of zinc element in the high-zinc material is 40% - 60%; And / or, the mass percentage of cadmium element in the high-cadmium soot is greater than 12%.

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