Method for preparing high-purity molybdenum trioxide from molybdenum concentrate having high copper content

Abstract

The present invention provides a method for producing high-purity molybdenum trioxide from a molybdenum concentrate having a high copper content, the method comprising: removing copper by using high-quality sulfuric acid produced by capturing sulfur dioxide gas generated during roasting; removing iron from the residue after acid leaching by using ammonia water; obtaining ammonium molybdate by evaporating, under reduced pressure, the filtrate obtained after ammonia water leaching; and again removing iron from the ammonium molybdate by water leaching, followed by calcination, thereby obtaining high-purity molybdenum trioxide with a purity of 99.9% or more.

Description

Method for producing high-purity molybdenum trioxide from molybdenum concentrate with high copper content

[0001] The present invention relates to a method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content.

[0002] Molybdenum oxide (MoO3) is a versatile material attracting global attention, receiving significant interest due to its chemical properties, high thermal and chemical stability, and redox chemistry resulting from its high reduction potential and electrochemical activity.

[0003] Due to its large bandgap and optical and electrical properties, molybdenum trioxide is considered a potentially suitable material for various technological applications, such as photocatalysts, water pollution treatment, gas sensing, battery electrodes, and catalysts. While numerous research results regarding this high applicability have been reported in various technological fields such as optics, environmental science, electrochemistry, and nanotechnology, there are still few known commercially available products in these fields.

[0004] Most molybdenum trioxide is currently used to manufacture ferromolybdenum alloys, but there is a lack of accurate information regarding the purity of molybdenum trioxide for steelmaking. Typically, molybdenum trioxide is produced from molybdenum sulfide concentrate (Molybdenite, MoS2) through a dry smelting process called roasting and supplied for steelmaking. At this time, the copper content in molybdenum trioxide is limited to 0.5%, and since the performance of ferromolybdenum deteriorates as the copper content increases, high-purity molybdenum trioxide is required.

[0005] In order to obtain high-purity molybdenum trioxide using this dry smelting method, a purification process using wet smelting after dry roasting is essential.

[0006] Korean Registered Patent No. 10-1878913 describes a method for producing molybdenum trioxide from molybdenum concentrate, wherein molybdenum concentrate is desulfurized and oxidized simultaneously using nitric acid, the resulting molybdic acid is selectively dissolved in an ammonia aqueous (NH4OH) solution, and the resulting solution is evaporated and concentrated under low temperature and low pressure conditions to recover solid ammonium molybdate ((NH4)2MoO4). The recovered ammonium molybdate is then dried to remove moisture and thermally decomposed to produce molybdenum trioxide. Additionally, nitrogen oxides (NO2) generated during the process x The process begins by regenerating ammonia (NH3) gas and reusing it in the process, recovering molybdenum from the generated waste liquid, removing sulfuric acid generated during the reaction, and simultaneously recovering it as gypsum.

[0007] Meanwhile, conventional technology using highly oxidizing nitric acid can lead to process corrosion.

[0008] Accordingly, the applicant has devised a method for producing high-purity molybdenum trioxide from a high-copper-content molybdenum concentrate by removing copper using sulfuric acid produced by capturing sulfur dioxide gas generated during roasting through strenuous efforts.

[0009] The present invention, aimed at solving the aforementioned conventional problems, is intended to provide a method for producing high-purity molybdenum trioxide from a high-copper-content molybdenum concentrate by removing copper using sulfuric acid produced by capturing sulfur dioxide gas generated during roasting.

[0010] The problems that the present invention aims to solve are not limited to those mentioned above, and other unmentioned problems will be clearly understood by those skilled in the art from the description below.

[0011] To achieve the above objective, according to one aspect of the present invention,

[0012] A method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content is,

[0013] A step of roasting molybdenum concentrate containing 0.5~5 wt% copper;

[0014] A step in which the sulfur dioxide gas generated in the above-mentioned roasting step is converted into sulfur trioxide gas through a catalytic oxidation reaction using a solid catalyst, and the sulfur trioxide gas is dissolved in water to produce sulfuric acid;

[0015] A step of leaching the molybdenum oxide obtained after the above-mentioned roasting step into the above-mentioned sulfuric acid and separating it into a first residue and a first leaching filtrate;

[0016] A step of washing the above first residue with water;

[0017] A step of leaching the washed first residue in ammonia water and then separating it into a second residue and a second leaching liquid;

[0018] A step of precipitating the first ammonium molybdate by evaporating the second leaching filtrate under reduced pressure;

[0019] A step of separating the first ammonium molybdate into a third residue and a filtrate of water after leaching the first ammonium molybdate, and precipitating the second ammonium molybdate by evaporating the filtrate of water under reduced pressure; and

[0020] The method includes the step of calcining the second ammonium molybdate to obtain molybdenum trioxide.

[0021] In addition, the above-mentioned roasting step is characterized by being performed under conditions of 500 to 700℃ and 1 to 10 hours.

[0022] In addition, the solid catalyst in the step of manufacturing the sulfuric acid is characterized as being vanadium pentoxide (V2O5).

[0023] The above sulfuric acid is characterized by having a concentration of 98%.

[0024] In addition, the step of manufacturing the sulfuric acid further includes the step of diluting the concentration of the sulfuric acid to 1M.

[0025] In addition, the solid-liquid ratio of the molybdenum oxide and the sulfuric acid is characterized as being 1:5 in the step of separating into the first residue and the first leaching liquid.

[0026] In addition, in the step of separating into the first residue and the first leaching filtrate, the leaching is performed under conditions of 20 to 25°C for 10 minutes.

[0027] In addition, the concentration of the ammonia water in the step of separating into the second residue and the second leaching filtrate is 5 to 20%.

[0028] In addition, the first ammonium molybdate is characterized by being represented by the following chemical formula 1.

[0029] [Chemical Formula 1]

[0030] (NH3) x Mo y O z ·αH2O

[0031] In addition, the step of precipitating the second ammonium molybdate is characterized by being performed two or more times.

[0032] In addition, the step of obtaining the molybdenum trioxide is characterized by performing the calcination at 600 to 800°C for 1 to 3 hours.

[0033] In addition, the purity of the molybdenum trioxide obtained in the step of obtaining the molybdenum trioxide is 99.9% or higher.

[0034] In addition, the copper content of the molybdenum trioxide in the step of obtaining the molybdenum trioxide is 0.08 wt% or less.

[0035] In addition, the ammonia gas generated after calcination in the step of obtaining the molybdenum trioxide is dissolved in water to produce ammonia water, and is reused when leaching the first residue.

[0036] According to the present invention, a method for producing high-purity molybdenum trioxide from a high-copper content molybdenum concentrate is provided, wherein copper is removed using high-quality sulfuric acid produced by capturing sulfur dioxide gas generated during roasting.

[0037] In addition, the present invention provides a method for producing high-purity molybdenum trioxide from a molybdenum concentrate with a high copper content, wherein iron is removed from the residue after acid leaching using ammonia water.

[0038] In addition, according to the present invention, a method for producing high-purity molybdenum trioxide from a high-copper-content molybdenum concentrate is provided, wherein the filtrate obtained after leaching with ammonia water is evaporated under reduced pressure to obtain ammonium molybdate, and the iron is removed by leaching with water.

[0039] In addition, according to the present invention, a method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content is provided, which reduces the use of chemicals by calcining ammonium molybdate to obtain high-purity molybdenum trioxide of 99.9% or higher and regenerating the ammonia gas generated during calcination to reuse it in the process.

[0040] The effects of the present invention are not limited to the effects described above, and should be understood to include all effects that can be inferred from the configuration of the invention described in the detailed description of the invention or the claims.

[0041] FIG. 1 is a batch process diagram of a method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content according to one embodiment of the present invention.

[0042] FIG. 1a is a diagram showing the first part of a batch process diagram of a method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content according to one embodiment of the present invention.

[0043] FIG. 1b is a diagram showing the second part of a batch process diagram of a method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content according to one embodiment of the present invention.

[0044] Figure 2a is an SEM image of molybdenum concentrate and the results of EDS element mapping analysis of a method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content according to one embodiment of the present invention.

[0045] FIG. 2b is an SEM image of molybdenum concentrate and the result of EDS spectrum analysis of a method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content according to one embodiment of the present invention.

[0046] FIG. 2c is an SEM image of molybdenum concentrate and the result of EDS spectrum analysis of a method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content according to one embodiment of the present invention.

[0047] Figure 3 is a graph showing the concentrations of Fe, Cu, and Mo in the acid leaching filtrate according to the acid leaching time of a method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content according to one embodiment of the present invention.

[0048] FIG. 4 shows ammonium molybdate ((NH3) obtained by vacuum evaporation after ammonia leaching in a method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content according to one embodiment of the present invention. x Mo y O z This is the X-ray diffraction pattern of ·αH2O).

[0049] Figure 5 is an X-ray diffraction pattern of molybdenum trioxide obtained after calcination in a method for producing high-purity molybdenum trioxide (MoO3) from molybdenum concentrate with a high copper content according to one embodiment of the present invention.

[0050] The present invention aims to provide a method for producing high-purity molybdenum trioxide from a high-copper-content molybdenum concentrate by removing copper using sulfuric acid produced by capturing sulfur dioxide gas generated during roasting.

[0051] Before describing the present invention in detail, it should be understood that the terms and words used in this specification should not be interpreted as being limited to their ordinary or dictionary meanings, and that the inventor of the present invention may appropriately define and use the concepts of various terms to best describe their invention, and furthermore, that these terms and words should be interpreted in a meaning and concept consistent with the technical spirit of the present invention.

[0052] In other words, it should be understood that the terms used in this specification are used merely to describe preferred embodiments of the present invention and are not intended to specifically limit the content of the present invention, and that these terms are defined in consideration of the various possibilities of the present invention.

[0053] In addition, it should be noted that in this specification, singular expressions may include plural expressions unless the context clearly indicates a different meaning, and that even if they are expressed in a similarly plural form, they may include a singular meaning.

[0054] Throughout this specification, where it is stated that a component "includes" another component, unless specifically stated otherwise, this may mean that it does not exclude any other component but may include any other component.

[0055] In addition, in describing the present invention below, detailed descriptions of components, such as prior art and known technologies, that are deemed to unnecessarily obscure the essence of the invention may be omitted.

[0056]

[0057] The present invention will be described in detail below with reference to the drawings.

[0058] FIG. 1 is a batch process diagram of a method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content according to one embodiment of the present invention.

[0059] As illustrated in FIG. 1, a method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content is,

[0060] A step of roasting molybdenum concentrate containing 0.5~5 wt% copper;

[0061] A step in which the sulfur dioxide gas generated in the above-mentioned roasting step is converted into sulfur trioxide gas through a catalytic oxidation reaction using a solid catalyst, and the sulfur trioxide gas is dissolved in water to produce sulfuric acid;

[0062] A step of leaching the molybdenum oxide obtained after the above-mentioned roasting step into the above-mentioned sulfuric acid and separating it into a first residue and a first leaching filtrate;

[0063] A step of washing the above first residue with water;

[0064] A step of leaching the washed first residue in ammonia water and then separating it into a second residue and a second leaching liquid;

[0065] A step of precipitating the first ammonium molybdate by evaporating the second leaching filtrate under reduced pressure;

[0066] A step of separating the first ammonium molybdate into a third residue and a filtrate of water after leaching the first ammonium molybdate, and precipitating the second ammonium molybdate by evaporating the filtrate of water under reduced pressure; and

[0067] The method includes the step of calcining the second ammonium molybdate to obtain molybdenum trioxide.

[0068] The present invention provides a method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content, wherein copper is removed using high-quality sulfuric acid produced by capturing sulfur dioxide gas generated during roasting, iron is removed from the residue after acid leaching using ammonia water, ammonium molybdate is obtained by vacuum evaporation of the filtrate obtained after ammonia water leaching, and the ammonium molybdate from which iron is removed again by water leaching is calcined to obtain high-purity molybdenum trioxide of 99.9% or higher.

[0069]

[0070] Step of roasting molybdenum concentrate containing 0.5~5 wt% copper

[0071] Low-grade molybdenum concentrate (MoS2) containing 0.5~5 wt% copper can be crushed using a dry grinder, and the crushed molybdenum concentrate can be obtained in powder form by sieving.

[0072] Here, the dry grinder may be a shredder, cut crusher, jaw crusher, cone crusher, hammer mill, rod mill, or ball mill, but is not limited thereto.

[0073] The particle size of the above-mentioned crushed molybdenum concentrate powder may follow known technology and the general knowledge of a person skilled in the art, but preferably, it may be 50 μm to 300 μm.

[0074] The above roasting step can be performed under conditions of 500 to 700℃ and 1 to 10 hours.

[0075] In the above-mentioned roasting step, the furnace is not limited to any furnace that supports a uniform oxidation reaction through stirring action such as rotation, and a rotary kiln can be cited as a non-limiting example thereof.

[0076] In addition, the above-mentioned roasting step is performed in an oxygen-containing atmosphere, and preferably, it may be a mixed atmosphere of air, oxygen, and an inert gas.

[0077] In addition, the above-mentioned roasting step can be performed without using other auxiliary agents known in the art.

[0078] Here, when the above-mentioned roasting step is performed within the above-mentioned temperature and time range, the molybdenum concentrate (MoS2) in powder form is oxidized by oxygen according to the following reaction scheme 1 to produce molybdenum oxide (MoO3) and a high concentration of sulfur dioxide (SO2) gas, and the sulfur dioxide gas produced at this time can be collected to produce a high-quality sulfuric acid solution, and the leaching process can be performed more effectively in a subsequent process using the sulfuric acid solution.

[0079] [Reaction Equation 1]

[0080] MoS2+ 3.5O2= MoO3+ 2SO2

[0081] The sulfur dioxide gas generated during the roasting stage is converted into sulfur trioxide gas through a catalytic oxidation reaction using a solid catalyst, and the sulfur trioxide gas is dissolved in water to produce sulfuric acid.

[0082] In the step of producing the sulfuric acid above, the solid catalyst is vanadium pentoxide (V2O5).

[0083] Here, it is preferable to carry out the step of producing the sulfuric acid while stirring to further increase reaction efficiency.

[0084] Here, in the step of producing the sulfuric acid, platinum (Pt), titanium dioxide (TiO2), etc., can be used as a solid catalyst, but by using vanadium pentoxide, which has excellent durability against sulfur dioxide gas as proposed in the present invention, the activity between the sulfur dioxide gas and the catalyst can be further improved, and thus sulfur trioxide gas can be obtained at a rapid rate as shown in Reaction Scheme 2 below.

[0085] [Reaction Equation 2]

[0086]

[0087] It is desirable that the vanadium pentoxide has a porous structure.

[0088] Here, when the catalytic oxidation reaction is carried out under the pressure and temperature conditions in the step of producing the sulfuric acid, the generated high concentration of sulfur dioxide (SO2) gas and oxygen react with the help of a vanadium pentoxide catalyst to obtain a high concentration of sulfur trioxide (SO3) gas, and the generated sulfur trioxide gas can be dissolved in water to produce a high concentration sulfuric acid solution, and the sulfuric acid solution can be used in a subsequent process to perform the leaching process more effectively.

[0089] Here, in the step of manufacturing the sulfuric acid, the sulfur trioxide gas can be directly dissolved in water without using sulfuric acid.

[0090] [Reaction Equation 3]

[0091]

[0092] Here, when the temperature of the water in the step of manufacturing the sulfuric acid is within the above range, the high-temperature sulfur trioxide gas can be well dissolved in the water, and sulfuric acid mist is not generated due to the temperature difference between the sulfur trioxide gas and the water and the heat released during the reaction, thereby improving the recovery rate of sulfuric acid. Consequently, a high-concentration sulfuric acid solution can be manufactured, and the leaching process can be performed more effectively in a subsequent process using the sulfuric acid solution.

[0093] High-quality, high-concentration sulfuric acid is obtained through the method described above.

[0094] The step of manufacturing the sulfuric acid may further include the step of diluting the concentration of the sulfuric acid to 1M.

[0095] Here, when the sulfuric acid is diluted to the above concentration, the copper present in the molybdenum oxide can be significantly removed when the molybdenum oxide obtained after roasting is leached using the sulfuric acid of the above concentration, and thus high-purity molybdenum trioxide can be obtained.

[0096] Step of leaching the molybdenum oxide obtained after the roasting step into sulfuric acid and separating it into a first residue and a first leaching filtrate

[0097] In the step of separating into the first residue and the first leaching filtrate, the solid-liquid ratio of the molybdenum oxide and the sulfuric acid may be 1:5.

[0098] Here, when the solid-to-liquid ratio of the molybdenum oxide and the sulfuric acid is within the above range, the copper present in the molybdenum oxide obtained after roasting can be significantly dissolved in the leaching solution, and no loss of molybdenum occurs.

[0099] In the step of separating into the first residue and the first leaching filtrate, the leaching can be performed under conditions of 20 to 25°C for 10 minutes.

[0100] Here, when the above molybdenum oxide is leached with sulfuric acid within the above temperature and time range, the copper present in the molybdenum oxide can be significantly dissolved in the leaching solution, the loss of molybdenum can be minimized, and thus high-purity molybdenum trioxide can be obtained.

[0101] If the above molybdenum oxide is leached with sulfuric acid for less than 10 minutes, there is not enough time to dissolve the copper present in the molybdenum oxide into the leaching solution, and if it is leached for more than 10 minutes, it may only increase the process time and not have a significant effect on the copper leaching rate.

[0102] In this step, the first residue and the first leaching filtrate can be separated into the first residue and the first leaching filtrate using filter paper.

[0103] The first leaching filtrate obtained in this step is a copper-concentrated solution, and it can be recovered as copper metal through an additional reduction process.

[0104] Step 1: Washing the residue with water

[0105] Here, the step of washing the first residue with water is performed to remove acid present in the first residue obtained in the preceding process, and the number of washes is not specifically limited.

[0106] The first residue obtained after washing may be dried in an atmospheric oven, and the temperature and time are not specifically limited.

[0107] Step of leaching the washed first residue in ammonia water and separating it into a second residue and a second leaching filtrate

[0108] In the step of separating into the second residue and the second leaching filtrate, it is preferable that the concentration of the ammonia water be 5 to 20%.

[0109] Here, when the washed first residue is leached using ammonia water within the concentration range, the iron present in the first residue may precipitate in the leaching solution, and the molybdenum may be dissolved in the ammonia water in a saturated state.

[0110] In this step, the second residue and the second leaching filtrate can be separated into the second residue and the second leaching filtrate using filter paper.

[0111] Step of precipitating the first ammonium molybdate by evaporating the second leaching filtrate under reduced pressure

[0112] Ammonium molybdate can be precipitated using a vacuum evaporator with the second leaching filtrate obtained from the preceding process.

[0113] Here, the vacuum evaporation can be performed at a temperature of 60 to 80°C, thereby maximizing the specific surface area of ​​the second leaching liquid containing molybdenum, reducing energy costs, and improving the recovery rate and purity of the crystallized ammonium molybdate.

[0114] In this step, the first ammonium molybdate may be ammonium molybdate with a purity of 98% and may be represented by the following chemical formula 1.

[0115] [Chemical Formula 1]

[0116] (NH3) x Mo y O z ·αH2O

[0117] In a specific example, the first ammonium molybdate is (NH3)2Mo1O3·H2O, (NH3)6Mo6O 21 It may be ·7H2O, and even if not specified in the specific examples, if it is ammonium molybdate having the chemical formula 1 expressed above, it can be produced as the high-purity molybdenum trioxide intended for the present invention.

[0118] Here, the first ammonium molybdate having the above chemical formula is in the form of a water-soluble molybdenum salt, which has the effect of effectively separating and concentrating molybdenum through a subsequent water leaching process.

[0119] A step of separating the first ammonium molybdate into a third residue and an aqueous leaching filtrate after water leaching, and precipitating the second ammonium molybdate by vacuum evaporation of the aqueous leaching filtrate.

[0120] It is preferable to perform the step of precipitating the second ammonium molybdate at least twice.

[0121] Here, when the first ammonium molybdate is subjected to water leaching and vacuum evaporation within the above range of times, the iron present in the first ammonium molybdate can be effectively removed, thereby obtaining a second ammonium molybdate with a purity of 99.9%, and in a subsequent process, the second ammonium molybdate can be calcined to obtain high-purity molybdenum trioxide.

[0122] If the first ammonium molybdate is subjected to water leaching and vacuum evaporation less than twice, it may be difficult to remove the iron present in the first ammonium molybdate, and consequently, problems may arise in producing high-purity molybdenum trioxide by calcining the second ammonium molybdate in a subsequent process.

[0123] Step of obtaining molybdenum trioxide by calcining ammonium 2 molybdate

[0124] Molybdenum trioxide can be obtained by calcining the ammonium 2 molybdate obtained in the preceding process using an electric furnace.

[0125] In the step of obtaining the molybdenum trioxide above, the calcination can be performed under conditions of 600 to 800°C and 1 to 3 hours.

[0126] Here, when the second ammonium molybdate is calcined under the temperature and time conditions, the ammonium molybdate is thermally decomposed to obtain molybdenum trioxide having high purity and high crystallinity.

[0127] High-purity molybdenum trioxide with significantly removed copper and iron is obtained through the method described above.

[0128] In the step of obtaining the molybdenum trioxide above, the purity of the molybdenum trioxide may be 99.9% or higher.

[0129] In the step of obtaining the molybdenum trioxide, the copper content of the molybdenum trioxide may be 0.08 wt% or less.

[0130] In addition, the ammonia gas generated after calcination in the step of obtaining the molybdenum trioxide can be dissolved in water to produce ammonia water and reused when leaching the first residue.

[0131] As described above, the method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content according to one embodiment of the present invention has the effect of saving resources and reducing the consumption of chemicals by recycling process by-products.

[0132] In addition, the method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content according to one embodiment of the present invention has the advantageous effect of obtaining molybdenum trioxide with a significantly reduced copper content and applying it in the production of ferromolybdenum alloys.

[0133] Hereinafter, a method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content according to one embodiment of the present invention will be explained with reference to the following experimental examples.

[0134] Molybdenum trioxide was prepared through the following examples.

[0135]

[0136] <Example>

[0137] <Example 1> Method for producing high-purity molybdenum trioxide from molybdenum concentrate with high copper content

[0138] First, molybdenum sulfide concentrate (MoS2) was collected and prepared. The prepared molybdenum concentrate was analyzed for composition using an inductively coupled plasma analyzer (ICP-MS). The results are shown in [Table 1] below.

[0139] Mo (wt%)Cu (wt%)Fe (wt%)MoS252.80.701.58

[0140]

[0141] Figure 2a is an SEM image of molybdenum concentrate and the results of EDS element mapping analysis of a method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content according to one embodiment of the present invention.

[0142] FIG. 2b is an SEM image of molybdenum concentrate and the results of EDS element mapping analysis of a method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content according to one embodiment of the present invention.

[0143] As shown in FIGS. 2a, 2b, 2c and [Table 1] above, the prepared molybdenum concentrate contained 0.70 wt% Cu and 1.58 wt% Fe. This was ground using a rod mill and sieved to prepare molybdenum concentrate powder with a particle size of approximately 300 μm. The prepared molybdenum concentrate powder was loaded into a rotary kiln and roasted at 600°C for 5 hours in an atmospheric environment with a continuous supply of air. After the roasting process was completed, the generated sulfur dioxide gas was collected and transferred to an oxidizer, and the resulting molybdenum oxide was recovered. The collected sulfur dioxide gas was oxidized using a vanadium pentoxide (V2O5) catalyst to convert it into sulfur trioxide gas. The sulfur trioxide gas was purged into water through a pipe and dissolved by stirring. Finally, 98% high-purity sulfuric acid was obtained. The obtained sulfuric acid was diluted to a concentration of 1 M using distilled water. 200 g of molybdenum oxide was added to 1000 g of 1 M sulfuric acid and leached at room temperature for 10 minutes, after which the first residue and the first leaching filtrate were separated using filter paper. The obtained first residue was washed three times with distilled water and then leached in 15 vol% ammonia water (NH4OH) at room temperature for 2 hours, after which the second residue and the second leaching filtrate were separated using filter paper. The obtained second leaching filtrate was charged into a vacuum evaporator, the pressure inside the reactor was reduced to approximately 1 bar, and crystallized first ammonium molybdate (98% purity) was obtained at an internal temperature of 70°C. The obtained first ammonium molybdate was crystallized into second ammonium molybdate (99.9% purity) by performing the water leaching and vacuum evaporation process twice. The obtained ammonium 2 molybdate was charged into an electric furnace and calcined at 800°C for 3 hours to obtain molybdenum trioxide (MoO3) with a purity of 99.9%.

[0144]

[0145] <Example 2> Method for producing high-purity molybdenum trioxide from molybdenum concentrate with high copper content

[0146] Molybdenum concentrate identical to that in Example 1 was prepared. It was ground using a rod mill and sieved to prepare molybdenum concentrate powder with a particle size of approximately 280 μm or less. The prepared molybdenum concentrate powder was loaded into a rotary kiln and roasted at 500°C for 8 hours under an atmospheric atmosphere. After the roasting process was completed, the generated sulfur dioxide gas was collected and transferred to an oxidizer, and the resulting molybdenum oxide was recovered. The collected sulfur dioxide gas was oxidized at 400°C under an atmospheric atmosphere using a vanadium pentoxide (V2O5) catalyst to convert it into sulfur trioxide gas. The sulfur trioxide gas was purged into water through a tube and dissolved by stirring. Finally, 98% high-purity sulfuric acid was obtained. The obtained sulfuric acid was diluted to a concentration of 1 M using distilled water. 200g of molybdenum oxide was added to 1000g of 1M sulfuric acid and leached at room temperature for 10 minutes, after which the mixture was separated into a first residue and a first leaching filtrate using filter paper. The obtained first residue was washed three times with distilled water and then leached in 15 vol% ammonia water (NH4OH) at room temperature for 2 hours, after which it was separated into a second residue and a second leaching filtrate using filter paper. The obtained second leaching filtrate was charged into a vacuum evaporator, the pressure inside the reactor was reduced to 1 bar, and crystallized first ammonium molybdate (98% purity) was obtained at an internal temperature of 70°C. The obtained first ammonium molybdate was crystallized into second ammonium molybdate (99.9% purity) by performing the water leaching and vacuum evaporation process twice. The obtained ammonium 2 molybdate was charged into an electric furnace and calcined at 800°C for 2 hours to obtain molybdenum trioxide (MoO3) with a purity of 99.9%.

[0147]

[0148] <Comparative Example 1>

[0149] Comparative Example 1 was performed by preparing molybdenum trioxide in the same manner as Example 1 described above, but changing the leaching time to 30 minutes when leaching the molybdenum oxide obtained after roasting into 1M sulfuric acid.

[0150]

[0151] <Comparative Example 2>

[0152] Comparative Example 2 was performed by preparing molybdenum trioxide in the same manner as Example 1 described above, but changing the leaching time to 60 minutes when leaching the molybdenum oxide obtained after roasting into 1M sulfuric acid.

[0153]

[0154] <Experimental Example>

[0155] <Experimental Example 1> Component analysis of molybdenum oxide obtained after roasting

[0156] The molybdenum oxide obtained after roasting in Example 1 described above was subjected to component analysis using an inductively coupled plasma analyzer (ICP-MS). The results are as shown in [Table 2] below.

[0157] Mo (wt%) Cu (wt%) Fe (wt%) MoO3 (Rotary Kiln Concentrate Roast) 53.5 0.8 11.89

[0158]

[0159] Referring to [Table 2] above, it was confirmed that the roasted product obtained after oxidizing and roasting molybdenum concentrate containing copper and iron by charging it into a rotary kiln was low-purity molybdenum oxide.

[0160]

[0161] <Experimental Example 2> Analysis of Copper Concentration in Leachate According to Acid Leaching Time

[0162] In the above-described Example 1, Comparative Example 1, and Comparative Example 2, molybdenum oxide obtained after roasting was added to 1M sulfuric acid, and the copper concentration of the leaching filtrate was analyzed at leaching times of 10, 30, and 60 minutes.

[0163] Figure 3 is a graph showing the concentrations of Fe, Cu, and Mo in the acid leaching filtrate according to the acid leaching time of a method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content according to one embodiment of the present invention.

[0164] As shown in Fig. 3, when the molybdenum oxide obtained after roasting in Example 1 was leached in 1M sulfuric acid for 10 minutes, it was confirmed that Fe hardly dissolved in the leaching solution, while Cu and Mo dissolved in the leaching solution. Meanwhile, when the leaching time was increased in Comparative Examples 1 and 2, the Cu concentration in the leaching solution showed almost no change, and the Mo concentration continued to increase. Therefore, according to the method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content of the present invention, optimal acid leaching conditions were established to remove copper while minimizing molybdenum loss.

[0165]

[0166] <Experimental Example 3> Ammonium Molybdate XRD Analysis

[0167] Phase analysis of the first ammonium molybdate obtained by vacuum evaporation of the second leaching filtrate obtained after ammonia leaching in Example 1 described above was performed. Phase analysis was carried out using an X-ray diffractometer at a speed of 5° / min at a 2θ angle in the range of 0 to 65°.

[0168] FIG. 4 shows ammonium molybdate ((NH3) obtained by vacuum evaporation after ammonia leaching in a method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content according to one embodiment of the present invention. x Mo y O z This is the X-ray diffraction pattern of ·αH2O).

[0169] As shown in Fig. 4, the (NH3)2Mo1O3·H2O phase and (NH3)6Mo6O 21 A crystalline, 98% pure water-soluble molybdenum salt with a mixed ·7H2O phase was observed. Therefore, it was confirmed that copper was significantly removed according to the method of producing high-purity molybdenum trioxide from high-copper molybdenum concentrate of the present invention.

[0170]

[0171] <Experimental Example 4> Molybdenum Trioxide XRD and ICP Analysis

[0172] Phase analysis and compositional analysis were performed on molybdenum trioxide obtained by calcining the second ammonium molybdate obtained after two water leachings in the aforementioned Examples 1 and 2. Phase analysis was performed using an X-ray diffractometer at a speed of 5° / min at a 2θ angle in the range of 0 to 65°. Compositional analysis was performed using an inductively coupled plasma analyzer (ICP-MS). The results are as shown in [Table 3] below.

[0173] Figure 5 is an X-ray diffraction pattern of molybdenum trioxide obtained after calcination in a method for producing high-purity molybdenum trioxide (MoO3) from molybdenum concentrate with a high copper content according to one embodiment of the present invention.

[0174] As shown in Fig. 5, crystalline molybdenum trioxide having the MoO3 phase was observed in all of Examples 1 and 2.

[0175] Mo (wt%) Cu (wt%) Fe (wt%) MoO3 (%) Example 1 99.9 Example 2 99.9

[0176]

[0177] Referring to [Table 3] above, it was confirmed that molybdenum trioxide with a purity of 99.9% or higher was obtained in all of Examples 1 and 2. Therefore, it was confirmed that high-purity molybdenum trioxide with reduced copper and iron content is obtained according to the method of producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content according to the present invention.

[0178]

[0179] Although various preferred embodiments of the present invention have been described above with some examples, the descriptions of various embodiments described in the "Specific details for carrying out the invention" section are merely illustrative, and those skilled in the art to which the present invention pertains will understand that the present invention can be carried out with various modifications or equivalent embodiments from the above description.

[0180] In addition, since the present invention can be implemented in various other forms, the present invention is not limited by the description above. The above description is provided merely to make the disclosure of the present invention complete and to fully inform those skilled in the art of the scope of the present invention, and it should be understood that the present invention is defined only by each claim of the claims.

[0181] According to the present invention, a method for producing high-purity molybdenum trioxide from a high-copper content molybdenum concentrate is provided, wherein copper is removed using high-quality sulfuric acid produced by capturing sulfur dioxide gas generated during roasting.

[0182] In addition, the present invention provides a method for producing high-purity molybdenum trioxide from a molybdenum concentrate with a high copper content, wherein iron is removed from the residue after acid leaching using ammonia water.

[0183] In addition, according to the present invention, a method for producing high-purity molybdenum trioxide from a high-copper-content molybdenum concentrate is provided, wherein the filtrate obtained after leaching with ammonia water is evaporated under reduced pressure to obtain ammonium molybdate, and the iron is removed by leaching with water.

[0184] In addition, according to the present invention, a method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content is provided, which reduces the use of chemicals by calcining ammonium molybdate to obtain high-purity molybdenum trioxide of 99.9% or higher and regenerating the ammonia gas generated during calcination to reuse it in the process.

Claims

A step of roasting molybdenum concentrate containing 0.5~5 wt% copper; A step in which the sulfur dioxide gas generated in the above-mentioned roasting step is converted into sulfur trioxide gas through a catalytic oxidation reaction using a solid catalyst, and the sulfur trioxide gas is dissolved in water to produce sulfuric acid; A step of leaching the molybdenum oxide obtained after the above-mentioned roasting step into the above-mentioned sulfuric acid and separating it into a first residue and a first leaching filtrate; A step of washing the above first residue with water; A step of leaching the washed first residue in ammonia water and then separating it into a second residue and a second leaching liquid; A step of precipitating the first ammonium molybdate by evaporating the second leaching filtrate under reduced pressure; A step of separating the first ammonium molybdate into a third residue and a filtrate of water after leaching the first ammonium molybdate, and precipitating the second ammonium molybdate by evaporating the filtrate of water under reduced pressure; and The step of obtaining molybdenum trioxide by calcining the second ammonium molybdate; comprising A method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content.

2. In Paragraph 1, The above roasting step is characterized by being performed under conditions of 500 to 700℃ and 1 to 10 hours. A method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content.

3. In Paragraph 1, The step of producing the above sulfuric acid is characterized in that the solid catalyst is vanadium pentoxide (V2O5). A method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content.

4. In Paragraph 1, Characterized by the concentration of the above sulfuric acid being 98%, A method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content.

5. In Paragraph 1, The step of manufacturing the sulfuric acid further comprises the step of diluting the concentration of the sulfuric acid to 1M, characterized in that A method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content.

6. In Paragraph 1, Characterized in that, in the step of separating into the first residue and the first leaching filtrate, the solid-liquid ratio of the molybdenum oxide and the sulfuric acid is 1:

5. A method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content.

7. In Paragraph 1, Characterized in that, in the step of separating into the first residue and the first leaching filtrate, the leaching is performed under conditions of 20 to 25°C for 10 minutes. A method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content.

8. In Paragraph 1, Characterized in that, in the step of separating into the second residue and the second leaching filtrate, the concentration of the ammonia water is 5 to 20%. A method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content.

9. In Paragraph 1, The above first ammonium molybdate is characterized by being represented by the following chemical formula 1, A method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content. [Chemical Formula 1] (NH3) x Mo y O z ·αH2O 10. In Paragraph 1, The step of precipitating the second ammonium molybdate is characterized by being performed two or more times. A method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content.

11. In Paragraph 1, The step of obtaining the molybdenum trioxide is characterized by performing the calcination under conditions of 600 to 800°C and 1 to 3 hours. A method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content.

12. In Paragraph 1, Characterized in that, in the step of obtaining the molybdenum trioxide, the purity of the molybdenum trioxide is 99.9% or higher. A method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content.

13. In Paragraph 1, Characterized in that, in the step of obtaining the molybdenum trioxide, the copper content of the molybdenum trioxide is 0.08 wt% or less. A method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content.

14. In Paragraph 1, The ammonia gas generated after calcination in the step of obtaining the molybdenum trioxide is dissolved in water to produce ammonia water, and is reused when leaching the first residue, characterized by A method for producing high-purity molybdenum trioxide from molybdenum concentrate with a high copper content.

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