Method for manufacturing titanium concentrate from low grade titanium ore, and titanium concentrate thereof

Abstract

The present invention relates to a beneficiation method for producing titanium concentrate from low-grade titanium ore and titanium concentrate recovered therefrom. The present invention provides a beneficiation method for producing titanium concentrate from low-grade titanium ore, characterized by comprising: (a) a step of crushing / heavy-crushing low-grade titanium ore; (b) a step of sieving the crushed / heavy-crushed material; (c) a step of mixing the sieved material with a reducing agent; (d) a step of magnetizing and roasting the mixture of the crushed material and the reducing agent; (e) a step of separating the magnetized and roasted product into individual components; and (f) a step of wet magnetic separation of the crushed magnetized and roasted product. In addition, the present invention provides titanium concentrate recovered by a beneficiation method for producing titanium concentrate from the low-grade titanium ore described above.

Description

Technology Field

[0001] The present invention provides a beneficiation method for producing titanium concentrate by magnetizing and roasting titanium ore, which is a sedimentary rock composed of hematite with very low magnetic sensitivity and rutile with almost no magnetic sensitivity, using microwaves to alter it into iron-containing titanium minerals with high magnetic sensitivity, namely titanomagnetite, ilmenite (iron nitrite), and ulvospinel, followed by magnetic separation. Background Technology

[0003] Titanium is the ninth most abundant element in the Earth's crust, and more than 60 types of minerals are known. The major titanium minerals are shown in Table 1.

[0004] Of these, the titanium resources used industrially are ilmenite (FeO·TiO2) and rutile (TiO2). Since the output of rutile is low, ilmenite accounts for more than 90%.

[0005] Although ilmenite is a paramagnetic material, it has high magnetic sensitivity, so it is mostly recovered from placer mines by combining specific gravity separation with magnetic separation.

[0006] In contrast, rutile has almost no magnetic sensitivity, so it cannot be recovered by magnetic separation; therefore, it is mostly recovered by combining specific gravity separation or flotation separation.

[0008]

[0009] Titanium-containing iron ore produced in Korea, such as at the Gwanin Mine, Yeonpyeong Mine, Soyeonpyeongdo, and Hadong, is a titanomagnetite deposit produced in Stage 1 as described below, and is an ore composed mainly of magnetite (Fe3O4) and ilmenite (FeO·TiO2).

[0010] However, the titanium-containing iron ore found in the Myeonsan Formation in the Taebaek region is a titanohematite-type ore formed by the oxidation reaction of the magma parent rock in stages 5 to 6, and is a sedimentary rock composed of rutile (TiO2) and hematite (Fe2O3). Therefore, it is considered to be the only unique titanium ore in the world that is distinctly different in terms of ore deposit origin and rock-forming minerals.

[0012] Step 1: Homogeneous Ilmenite (FeO·TiO₂) 2 )

[0013] Step 2: ferrian ilmenite(FeO·TiO2) + ferrian rutile(TiO2)

[0014] Step 3: ferrian rutile(TiO2)+[ferrian ilmenite(FeO·TiO2)]

[0015] Step 4: rutile(TiO2)+titanohematite(Fe2O3)+ferrian rutile(TiO2)+[ferrian ilmenite(FeO·TiO2)]

[0016] Step 5: rutile(TiO₂) 2 ) + titanohematite(Ti 0.7 Fe 1.3 O 3 )

[0017] Step 6: rutile + titanohematite + [pseudobrookite(Fe2O3·TiO2)]

[0018] Step 7: pseudobrookite(Fe2O3·TiO2)

[0020] Titanium ore composed of magnetite (Fe3O4) and ilmenite (Fe2O2), such as that found in the Gwanin Mine, allows for easy production of titanium concentrate through magnetic separation provided that the elements are properly separated; however, in the case of titanium ore from the Myeonsan Formation in the Taebaek region—a sedimentary rock composed of non-magnetic rutile (TiO2), weakly magnetic hematite (Fe2O3), and large amounts of gangue minerals—it is difficult to produce high-grade titanium concentrate through magnetic separation.

[0021] This is because rutile is a non-magnetic mineral, making it difficult to separate by magnetic force, and since only titanium oxide components existing in the form of weakly magnetic titanohematite (a mixture of hematite and rutile) can be separated by magnetic force, there are limitations in increasing the recovery rate of titanium oxide.

[0022] In addition, when titanium ore is over-crushed for separation, it is physically separated into hematite and rutile, so the finer the powder, the lower the yield of titanium oxide (rutile) becomes.

[0023] Therefore, the inventors of the present invention expected that efficient beneficiation could be achieved by applying magnetization roasting technology, a pretreatment technology for iron ore beneficiation, to titanium ore from the Myeonsan Formation in the Taebaek region to react rutile and hematite to transform them into iron-containing titanium minerals with high magnetic sensitivity, and then recovering these transformed minerals through magnetic separation.

[0024] In addition, the inventors of the present invention have devised a method for magnetizing and roasting titanium ore using a microwave heating method to reduce thermal energy and grinding costs during magnetizing and roasting. Therefore, the magnetizing and roasting method and the microwave heating technology will be briefly described below.

[0025] Magnetizing Roasting

[0026] The magnetizing roasting that the inventors of the present invention intend to use is a type of metallurgical process used in the conventional mineral processing (benefiting) field.

[0027] Magnetization roasting can be viewed as a chemical beneficiation pretreatment process that converts non-magnetic iron ore into magnetic material using heat and reducing gas.

[0028] In particular, when attempting to recover iron from weakly magnetic iron ores such as limonite or hematite, and when it is difficult to obtain high-grade iron concentrate using only simple physical beneficiation methods, this is widely used to increase beneficiation efficiency by converting these minerals with low magnetic sensitivity into ferromagnetic materials (magnetite) with high magnetic sensitivity.

[0029] In other words, by heating iron ore (mainly limonite, hematite, etc.) to a certain temperature and then causing a chemical reaction in a specific reducing atmosphere to convert the iron-containing minerals within the ore into magnetite (Fe3O4) which has strong magnetism, and then applying a magnetic separation process, the yield and grade of the iron concentrate can be significantly improved.

[0030] While magnetizing and roasting iron ore in this manner can significantly increase metal yield and yield high-grade iron concentrate powder, a drawback is that this technology is only suitable for certain economically viable iron ore beneficiation plants due to the disadvantages of massive investment in related equipment, complex process flow, and high operating costs.

[0032] Here, the titanium ore of the Myeonsan Formation in the Taebaek region used by the inventors of the present invention is a low-grade titanium ore composed of sedimentary rock in which non-magnetic rutile and weakly magnetic hematite are physically mixed through the following reaction in an oxidizing atmosphere when the host rock, ilmenite, forms the ore deposit.

[0033] Fe3O4(FeO·Fe2O3)+TiO2→ FeO·TiO2(Ilmenite) → 2FeO·TiO2(Ulvospinel) → Fe3O4-2FeO·TiO2solid solution(Titanomgnetite) → Fe2O3+TiO2

[0035] As such, when titanium ore composed of hematite and rutile is separated into individual components through fine grinding, non-magnetic rutile is difficult to recover by magnetic separation alone; since only rutile physically mixed with hematite can be recovered, there are limitations in increasing the recovery rate of titanium oxide and the grade of the concentrate.

[0037] Therefore, the inventors of the present invention expected that if titanium ore from the Myeonsan Formation in the Taebaek region is magnetized and roasted as a reduction reaction that reverses such an oxidation reaction, the hematite and rutile contained in the titanium ore from the Myeonsan Formation react as shown in the reaction equation below and can be converted into ferrimagnetic titanomagnetite (solid solution of ulvospinel and magnetite) and paramagnetic ulvospinel and ilmenite minerals, which are materials having magnetism as shown in Table 2, then separating these minerals from the gangue minerals and magnetically separating them would increase the yield of titanium oxide components (including iron components) and improve the grade of the concentrate.

[0038] Fe2O3+TiO2→ Fe3O4·2FeO·TiO2solid solution(Titanomagnetite) → 2FeO·TiO2(Ulvospinel) + Fe3O4→ FeO·TiO2(Ilmenite) → Fe+TiO2

[0040]

[0041] In order to achieve the problem to be solved by the present invention as described above, the inventors of the present invention expected that by mixing graphite (or coal, coke, or biomass) as a reducing agent with titanium ore from the Myeonsan Formation in the Taebaek region and performing magnetization roasting, the titanium ore (mainly hematite and rutile) produced from the Myeonsan Formation in the Taebaek region would be heated to a certain temperature according to the mechanism shown in Fig. 1, and then, when heat and reducing gas (CO) would undergo a chemical reaction in a specific reducing atmosphere, the rutile and hematite minerals within the ore would be converted into strongly magnetic titanomagnetite, ilmenite, and ulbospinel as shown in the phase diagram of Fig. 2, the yield and grade of titanium oxide concentrate could be significantly improved with only a relatively low magnetic strength using a magnetic separation method.

[0043] Microwave heating

[0044] Meanwhile, heating is required to perform magnetization roasting, but traditional roasting is a process that completely oxidizes oxide or sulfide minerals, resulting in very high energy consumption and a long roasting time; therefore, it is not economical to apply to relatively inexpensive minerals.

[0045] However, if magnetization roasting is performed through microwave heating, non-magnetic rutile and weakly magnetic hematite in titanium ore of the Myeonsan Formation in the Taebaek region can be converted into ferromagnetic or ferromagnetic materials through magnetization roasting at a relatively low temperature in a short time.

[0046] It was expected that this would have the advantage of reducing thermal and grinding energy, thereby lowering beneficiation costs, and improving the grade and yield of iron and titanium components.

[0047] Microwave heating is a type of dielectric heating that uses high-frequency electromagnetic waves (microwaves) to generate heat within the material itself.

[0048] In particular, microwaves typically use a frequency of about 2.45 GHz, and microwaves used for general purposes serve to vibrate and rotate polar molecules within food.

[0049] At this time, among the substances constituting the food, water molecules, in particular, have the properties of electric dipoles with positive (+) and negative (-) poles. When the direction of the microwave electric field changes rapidly by billions of times per second (in the case of 2.45 GHz), the water molecules within the food rotate rapidly and try to align in accordance with the movement of this electric field. In this process, as the water molecules rotate very rapidly and collide with each other, frictional heat (dielectric loss) is generated, and this heat heats the entire food (in the present invention, 'mineral').

[0050] While conventional heating using external heat sources (fire, heaters, etc.) transfers heat into the interior from the surface through conduction and convection, microwave heating is an internal heating method in which polar molecules (primarily water) inside the food generate heat directly.

[0051] Because the application of such microwave heating technology to the field of ore dressing offers significant advantages, such as reducing energy consumption for ore grinding, improving extraction efficiency of useful minerals, and removing harmful substances, it is being actively researched and applied as an innovative pretreatment technology in the fields of mineral processing (benefiting) and metallurgy.

[0052] In other words, by applying microwave technology to the pretreatment process of mineral processing (benefiting) using the principles of volumetric heating and selective heating—rather than conventional heat treatment methods (conduction, convection, and radiation)—advantages can be expected to improve beneficiation efficiency in the field of beneficiation, as described below.

[0053] First, it can improve the pulverization properties (e.g., micro-fracturing) for group separation.

[0054] Ore is generally composed of various types of minerals (useful minerals + gangue minerals), and each mineral has different dielectric properties (absorption rates) for microwaves.

[0055] When microwaves are irradiated, certain minerals with high absorption rates (e.g., pyrite) heat up very quickly, while surrounding gangue (e.g., quartz, calcite) heats up slowly or hardly at all.

[0056] As a result, a temperature difference occurs at the mineral interface, and thermal stress caused by this temperature difference forms micro-fracturing inside the ore. The ore with such fractures can be easily crushed and ground with much less energy during crushing and grinding, which drastically reduces grinding energy consumption and improves the crushing speed.

[0057] Secondly, it plays a role in increasing screening and extraction efficiency.

[0058] The occurrence of microcracks can increase the efficiency of subsequent processes, such as the beneficiation and extraction stages.

[0059] In addition, useful metal components (e.g., gold, copper) trapped within mineral particles are more easily exposed to the leaching solution through microcracks, thereby improving the metal recovery rate.

[0060] In addition, through microwave heating, some minerals (e.g., pyrite, siderite) can be selectively phase-transformed into magnetic minerals (e.g., magnetite).

[0061] The magnetized minerals are easily separated in the subsequent wet magnetic separation process, increasing separation efficiency.

[0062] Third, harmful substances can be removed (roasting process).

[0063] Traditional high-temperature roasting processes consume a lot of energy and make uniform heating difficult, but using microwaves reduces energy consumption and enables uniform heating.

[0064] For example, arsenic compounds (e.g., pyrophyllite, FeAsS) contained in some ores, such as gold ore, are selectively heated to high temperatures via microwaves to decompose and oxidize; this effectively removes arsenic, a harmful substance, thereby reducing the environmental burden in subsequent processes and increasing the metal yield.

[0066] Therefore, applying the aforementioned microwave heating technology to the titanium ore of the Myeonsan Formation in the Taebaek region, which is the focus of this invention, can yield the following advantages.

[0067] Because the minerals contained in the titanium ore of the Myeonsan Formation—namely rutile, hematite, and gangue minerals—have very low dielectric properties (absorption rates) for microwaves, the titanium ore of the Myeonsan Formation is not easily heated by microwaves alone.

[0068] However, when a reducing agent containing carbon is mixed with titanium ore and then irradiated with microwaves, the carbon added as a reducing agent has a high dielectric constant, so only the carbon is selectively heated by the microwaves; the CO gas generated at this time reduces the hematite and reacts with rutile to form iron-containing titanium minerals.

[0069] In this case, since gangue minerals such as quartz and clay are not heated and neither the surrounding air nor the equipment is heated, there is an advantage in reducing overall energy consumption.

[0070] Second, heat is generated directly within the carbonaceous material added as a reducing agent, rapidly raising the temperature required for magnetization roasting (the graphite itself is rapidly heated to 1,000 ℃ within 3 to 5 minutes of microwave irradiation time), thereby shortening the process time required for magnetization roasting.

[0071] In other words, traditional roasting is a process that completely oxidizes or reduces a target mineral, and since it requires heating the entire target mineral or even the surrounding air and equipment, it consumes a lot of energy and takes a long time. However, using microwaves has the advantage of being able to selectively reduce the target mineral while partially or completely heating it in a short time.

[0072] Third, as the minerals produced by magnetization roasting are rapidly heated and expanded, strong thermal stress is generated due to the temperature difference with the surrounding gangue, forming fine cracks inside the minerals and destroying the mineral structure, which greatly improves grindability, so the energy required to grind to the same size can be reduced by more than 10 to 30 percent.

[0073] Furthermore, since the degree of liberation is improved due to the enhancement of grindability, it becomes possible to increase the grade of the concentrate and the recovery rate of useful minerals during magnetic separation.

[0074] Therefore, in the mining sector, there is increasing demand for heating techniques using microwaves as a technology with great potential to simultaneously solve the energy-intensive and environmental problems of the existing mineral processing industry. Prior art literature

[0075] Republic of Korea Published Patent Application No. 10-1993-0016551 (Published Aug. 26, 1993) Republic of Korea Registered Patent Application No. 10-1815475 (Published Jan. 5, 2018) The problem to be solved

[0076] The problem to be solved by the present invention is to provide a beneficiation method for producing titanium concentrate with increased yield and grade of titanium and iron components by applying microwave magnetization roasting technology to titanium ore from the Myeonsan Formation in the Taebaek region, which consists of hematite with low magnetic sensitivity and rutile with almost no magnetic sensitivity, to convert it into iron-containing titanium minerals with high magnetic sensitivity, and then applying magnetic separation.

[0078] The problems that the present invention aims to solve are not limited to the problem(s) mentioned above, and other unmentioned problems will also be clearly understood from the following description by a person with ordinary knowledge in the technical field to which the present invention belongs ("person skilled in the art"). means of solving the problem

[0080] In order to solve the above problem, according to a preferred embodiment of the present invention, a beneficiation method for producing titanium concentrate from low-grade titanium ore according to the present invention comprises: (a) a step of crushing / heavy-crushing low-grade titanium ore; (b) a step of sieving the crushed / heavy-crushed material; (c) a step of mixing the sieved material with a reducing agent; (d) a step of magnetizing and roasting the mixture of the crushed material and the reducing agent; (e) a step of separating the magnetized and roasted product into individual components; and (f) a step of wet magnetic separation of the crushed magnetized and roasted product.

[0081] According to a preferred embodiment of the present invention, in the beneficiation method for producing titanium concentrate from low-grade titanium ore of the present invention, the titanium ore in step (a) may be composed of sedimentary rock containing hematite (Fe2O3) and rutile (TiO2).

[0082] In addition, according to a preferred embodiment of the present invention, the beneficiation method for producing titanium concentrate from low-grade titanium ore according to the present invention comprises, in the step of sieving the crushed / heavy-crushed ore of steps (a) and (b), the particle size (D) of the separated ore. 90 It is preferable that ) be 5 mm or less.

[0083] In addition, according to a preferred embodiment of the present invention, the beneficiation method for producing titanium concentrate from low-grade titanium ore according to the present invention is characterized by mixing coal, coke, and biomass as a reducing agent in an amount of 1.0 to 3.0 equivalents (3C / Fe2O3 = 1 equivalent) with the titanium ore of step (c).

[0084] In addition, according to a preferred embodiment of the present invention, the beneficiation method for producing titanium concentrate from low-grade titanium ore of the present invention preferably involves magnetizing and roasting a mixture of titanium ore and a reducing agent in a furnace at a temperature range of 900 to 1,200 ℃ for 0.5 to 6 hours for the magnetization roasting in step (d).

[0085] In addition, according to a preferred embodiment of the present invention, the beneficiation method for producing titanium concentrate from low-grade titanium ore according to the present invention may be such that the magnetization roasting in step (d) involves mixing 1.0 to 3.0 equivalents (3C / Fe2O3 = 1 equivalent) of coal and biomass as reducing agents with titanium ore (100 weight ratio) and heating the titanium ore mixture by irradiating it with microwaves having a single magnetron output range of 1 kW to 100 kW and a frequency of 915 MHz to 2.45 GHz for 5 to 60 minutes.

[0086] In addition, according to a preferred embodiment of the present invention, the beneficiation method for producing titanium concentrate from low-grade titanium ore according to the present invention may have the magnetization roasting product of step (d) be titanomagnetite, ulbospinel, and ilmenite, which are iron-containing titanium minerals.

[0087] In addition, according to a preferred embodiment of the present invention, the beneficiation method for producing titanium concentrate from low-grade titanium ore according to the present invention comprises, in the grinding step of the magnetized roasting product of step (e), the particle size (D) of the ground material. 90 It is preferable that the mesh size is 200 mesh (75 μm) or less.

[0088] In addition, according to a preferred embodiment of the present invention, in the magnetic separation step of the crushed magnetized roasting product of the present invention, the magnetic strength may have a range of 3,000 to 12,000 Gauss.

[0089] In addition, according to a preferred embodiment of the present invention, in the beneficiation method for producing titanium concentrate from low-grade titanium ore according to the present invention, the magnetic product recovered by magnetic separation in step (f) is preferably titanomagnetite and ilmenite, which are iron-containing titanium minerals, and ulbospinel, and metallic iron.

[0091] In addition, according to a preferred embodiment of the present invention, titanium concentrate recovered by the beneficiation method for producing titanium concentrate from low-grade titanium ore of the present invention described above can be provided.

[0093] Specific details of other preferred embodiments of the present invention are included in the "Specific details for carrying out the invention" section and the attached drawings.

[0094] The advantages and / or features of the present invention and the method for achieving them will become clear by referring to each embodiment of the "Specific details for carrying out the invention" section below, which is described with reference to the accompanying drawings.

[0095] However, the present invention is not limited to the embodiments described below but may be implemented in various different forms, and each embodiment of the present invention is provided merely to ensure that the disclosure of the present invention is complete and to fully inform a person skilled in the art of the scope and category of the present invention, and it should be understood that the present invention is defined by the scope of each claim. Effects of the invention

[0097] The beneficiation method for producing titanium concentrate from low-grade titanium ore according to the present invention provides a beneficiation method that increases the yield and grade of iron and titanium oxide through optimal crushing / grinding, microwave heating magnetization roasting, elemental separation, and magnetic separation.

[0098] In particular, low-grade titanohematite-type iron-containing titanium ore, known to be deposited in the Myeonsan Formation of the Taebaek region of South Korea in amounts of over 200 million tons, can be subjected to magnetization and roasting to react rutile and hematite to alter them into titanomagnetite (solid solution of Fe3O4-2FeO·TiO2), ilmenite, ulbospinel, and metallic iron, and then these calcined products are crushed and separated into individual components, and then magnetic separation can be performed to recover mainly high-grade titanium concentrates, such as titanomagnetite (solid solution of Fe3O4-2FeO·TiO2) and ilmenite.

[0099] In addition, according to the beneficiation method of the present invention for producing titanium concentrate from low-grade titanium ore, it is possible to replace ilmenite (FeO·TiO2) and titanium oxide, which are entirely dependent on imports for the production of titanium materials, with 100% domestic self-sufficiency, thereby saving foreign currency, and by increasing the production of high-grade titanium concentrate due to abundant reserves, it is possible to ultimately expect exports.

[0100] In addition, according to the beneficiation method for producing titanium concentrate from low-grade titanium ore of the present invention, since titanium concentrate can be supplied to domestic titanium utilization material industries and steel manufacturers at a lower cost than imported titanium ore (iron nitrite), the competitiveness of the titanium smelting industry and titanium material industry can be enhanced.

[0101] In addition, according to the beneficiation method for producing titanium concentrate from low-grade titanium ore of the present invention, other effects such as job creation and revitalization of the local community resulting from the development of new mines can also be expected.

[0102] In addition, there is an advantage in that by developing low-grade titanium ore, which is estimated to be deposited in large quantities of over 200 million tons domestically, we can become self-sufficient in raw materials for the titanium industry, which is currently almost entirely dependent on imports, thereby contributing to the revitalization of the domestic titanium industry.

[0104] The effects according to 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 composition of the invention described in the detailed description of the invention or the claims. Brief explanation of the drawing

[0106] FIG. 1 is a schematic diagram illustrating the principle of magnetization to explain a preferred embodiment of the present invention. Figure 2 is a diagram showing the phase diagram of FeO-Fe2O3-TiO2. FIG. 3 is a flowchart showing a beneficiation process for recovering titanium concentrate through magnetization roasting of titanium ore from the Myeonsan Formation in the Taebaek region. Figure 4 is a diagram showing the results of magnetic separation of iron-containing titanium minerals produced through the magnetization roasting of titanium ore in the Myeonsan Formation of the Taebaek region. Figure 5 is a diagram showing the results of X-ray diffraction analysis by type of titanium ore from the Myeonsan Formation in the Taebaek region used in the present invention. FIG. 6 is a diagram showing the SEM-EDS analysis results of a titanium ore flake from the Myeonsan Formation in the Taebaek region used in the present invention. FIG. 7 is a diagram showing the XRD analysis results of a product separated by specific gravity using a shaking table from titanium ore of the Myeonsan Formation in the Taebaek region in the present invention. FIG. 8 is a diagram showing the X-ray diffraction analysis results of a product produced by magnetizing and roasting titanium ore and graphite from the Myeonsan Formation in the Taebaek region in an experimental electric furnace at 900°C with varying mixing ratios in the present invention. FIG. 9 is a diagram showing the X-ray diffraction analysis results of a product produced by mixing low-grade titanium ore from the Myeonsan Formation in the Taebaek region and graphite at a mixing ratio of 1.5 equivalents (3C / Fe2O3 = 1 equivalent) in an experimental electric furnace and magnetizing and roasting at different temperatures in the present invention. FIGS. 10(a) and FIGS. 10(b) are drawings showing the X-ray diffraction analysis results of magnetic concentrate and magnetic tailings recovered by wet magnetic separation at 8,000 Gauss of the product produced by mixing low-grade titanium ore and graphite from the Myeonsan Formation in the Taebaek region at a mixing ratio of 1.5 equivalents (3C / Fe2O3 = 1 equivalent) in an experimental electric furnace at 900 ℃ in the present invention. FIG. 11 is a diagram showing the grade and yield of magnetic concentrate recovered by mixing low-grade titanium ore and graphite from the Myeonsan Formation in the Taebaek region at a mixing ratio of 1.5 equivalents (3C / Fe2O3 = 1 equivalent) in the present invention, magnetizing and roasting the resulting product at different temperatures, crushing the product, and wet magnetic separation at 8,000 Gauss. FIG. 12 is a diagram showing the X-ray diffraction analysis results of a product prepared by varying the microwave irradiation time in an experimental microwave heating furnace, wherein the material is a mixture of low-grade titanium ore from the Myeonsan Formation in the Taebaek region and graphite at a mixing ratio of 1.5 equivalents (3C / Fe2O3 = 1 equivalent) in the present invention. FIGS. 13a and 13b are drawings showing the X-ray diffraction analysis results of magnetic concentrate and magnetic tailings recovered by wet magnetic separation at 8,000 Gauss of a product prepared by varying the microwave irradiation time in an experimental microwave heating furnace, using a mixture of low-grade titanium ore and graphite from the Myeonsan Formation in the Taebaek region mixed at a ratio of 1.5 equivalents (3C / Fe2O3 = 1 equivalent) in the present invention. FIG. 14 is a diagram showing the yield and grade of magnetic concentrate recovered by wet magnetic separation at 8,000 Gauss from a product prepared by varying the microwave irradiation time in an experimental microwave heating furnace, using a mixture of low-grade titanium ore and graphite from the Myeonsan Formation in the Taebaek region in the present invention at a mixing ratio of 1.5 equivalents (3C / Fe2O3 = 1 equivalent). Specific details for implementing the invention

[0107] 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.

[0108] 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 various possibilities of the present invention.

[0109] 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.

[0110] 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.

[0111] Furthermore, it should be noted that in cases where it is stated that a component "exists inside or is installed in connection with" another component, this component may be installed in direct connection or contact with the other component, or it may be installed at a certain distance apart, and in the case where it is installed at a certain distance apart, there may be a third component or means for fixing or connecting the component to the other component, and a description of this third component or means may be omitted.

[0112] On the other hand, if it is stated that one component is "directly connected" or "directly connected" to another component, it should be understood that there is no third component or means.

[0113] Likewise, other expressions describing the relationship between each component, such as “between” and “right between”, or “adjacent to” and “directly adjacent to”, should be interpreted as having the same intent.

[0114] In addition, it should be understood that in this specification, terms such as “one side,” “other side,” “one side,” “other side,” “first,” “second,” etc., are used to clearly distinguish one component from another component, and that the meaning of the component is not restricted by such terms.

[0115] In addition, position-related terms such as "up," "down," "left," and "right" used in this specification should be understood as indicating the relative position of the corresponding component in the drawing, and unless an absolute position is specified, these position-related terms should not be understood as referring to an absolute position.

[0116] Furthermore, in specifying the reference numerals for each component of each drawing in this specification, the same component has the same reference numeral even if it is shown in different drawings; that is, the same reference numeral throughout the specification indicates the same component.

[0117] In the drawings attached to this specification, the size, position, connection relationships, etc., of each component constituting the present invention may be described in a partially exaggerated, reduced, or omitted manner for the convenience of explanation or to sufficiently clearly convey the concept of the present invention, and therefore, the proportions or scale may not be strictly accurate.

[0118] In addition, in the following description of the present invention, detailed descriptions of components that are deemed to unnecessarily obscure the essence of the present invention, such as known technologies including prior art, may be omitted.

[0120] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0122] FIG. 1 is a diagram schematically illustrating the principle of magnetization roasting to explain a preferred embodiment of the present invention, and is a diagram explaining the principle of magnetization roasting by microwaves targeting titanium ore of the Myeonsan Formation in the Taebaek region, and FIG. 2 is a diagram showing the phase diagram of FeO-Fe2O3-TiO2, which presents iron-containing titanium minerals that can be produced by magnetizing roasting hematite and rutile.

[0124] When titanium ore from the Myeonsan Formation in the Taebaek region, composed of rutile and magnetite, is mixed with coal and heated to magnetize and roast, hematite, which is a paramagnetic weak magnet, is first reduced to FeO and reacts with TiO2, a non-magnetic material, to form Fe3O4-2FeO·TiO2 solid solution (Titanomagnetite), which is a ferromagnetic material, and then further reduced so that magnetite is also reduced to Ulvospinel (2FeO·TiO2), and then Ilmenite (FeO·TiO2), which is paramagnetic but ferromagnetic.

[0126] Therefore, as can be seen from the FeO-Fe2O3-TiO2 phase diagram shown in Figure 2, it is expected that by applying magnetization roasting conditions such that titanomagnetite minerals become the main component and magnetically separating these minerals, the yield of titanium oxide components (including iron components) can be increased and the grade of the concentrate can be improved.

[0128] Fe2O3+TiO2→ Fe3O4-2FeO·TiO2solid solution(Titanomagnetite) → 2FeO·TiO2(Ulvospinel) + Fe3O4→ FeO·TiO2(Ilmenite) → Fe+TiO2

[0130] <Example 1>

[0131] Figure 3 is a flowchart showing a beneficiation process for recovering titanium concentrate through magnetization roasting of titanium ore in the Myeonsan Formation of the Taebaek region. It shows a process diagram for improving the recovery rate of iron and titanium dioxide by magnetization roasting of titanium ore buried in the Myeonsan Formation of the Taebaek region and magnetic separation.

[0132] According to FIG. 3, the beneficiation method for producing titanium concentrate from low-grade titanium ore according to the present invention may include a titanium ore preparation step (S100), a crushing step (S200), a heavy-chaining step (S300), a sieve separation step (S400), a mixing step with a reducing agent (S500), a magnetization roasting step (S600), a grinding step (S700), and a magnetic separation step (S800).

[0133] When passing through the magnetic separation step (S800), which is the last step among the above steps, magnetic minerals (i.e., titanium concentrate) are obtained on one hand, and non-magnetic minerals (i.e., tailings) can be discharged on the other.

[0134] Here, it should be noted that magnetic minerals are the minerals of focus in this invention, while non-magnetic minerals referred to as tailings are minerals not of focus in this invention.

[0136] Specifically, a preferred embodiment of the present invention according to FIG. 3 provides a beneficiation method for producing titanium concentrate from low-grade titanium ore, comprising: (a) a step of crushing / heavy-crushing low-grade titanium ore (corresponding to S200 and S300); (b) a step of sieving the crushed / heavy-crushed material (S400); a step of mixing the sieved material with a reducing agent (S500); a step of magnetizing and roasting the mixture of the crushed material and the reducing agent (corresponding to S600); a step of separating the magnetized and roasted product into individual parts (corresponding to S700); and a step of wet magnetic separation of the crushed magnetized and roasted product (corresponding to S800).

[0137] At this time, the step of magnetizing and roasting the mixture of the pulverized material and the reducing agent is preferably a step of magnetizing and roasting by microwave heating.

[0139] In FIG. 3, the titanium ore preparation step (S100) is a step of preparing low-grade titanium ore from the Myeonsan layer of the Taebaek region.

[0140] It should be noted that the titanium ore of the Myeonsan Formation in the Taebaek region targeted in this invention is a low-grade titanium ore composed of sedimentary rock in which non-magnetic rutile (TiO2) and weakly magnetic hematite (Fe2O3) are physically mixed.

[0142] The particle size (D) of the crushed ore in the crushing step (S200) and the heavy crushing step (S300) of the present invention 90 It is desirable that ) be 5 mm or less.

[0143] Although it is possible to further finer the particles, it is economically disadvantageous, and since larger particle sizes result in adverse effects on elemental separation and magnetization roasting, the particle size within the aforementioned range is most desirable.

[0144] In addition, in the present invention, the crushing step (S200) and the heavy-chaining step (S300) may be understood simply as a grinding step.

[0146] Next, a step (S400) of sieving the crushed / half-crushed material can be performed.

[0147] The particle size (D) of the sieve-separated ore in this step (S400) 90 It is preferable that the size be 5 mm or less, and if this is not satisfied, the sieve-separated ore may be returned to the crushing step (S200) mentioned above, particularly the heavy crushing step (S300), and crushed again.

[0148] Next, a step (S500) of mixing the crushed material with a reducing agent is performed. This step (S500) may be a step of mixing coal, coke, and biomass as a reducing agent in an amount of 1.0 to 3.0 equivalents (3C / Fe2O3 = 1 equivalent) with the titanium ore as the sieve-separated crushed material obtained in the above step (S400).

[0150] Next, the magnetization roasting step (S600) is a step of magnetizing a mixture of crushed material and a reducing agent, wherein graphite, coal and coke, and biomass are mixed as reducing agents in an equivalent ratio of 1.0 to 3.0 to 100 weight parts of titanium ore, and magnetized roasted in a furnace at a temperature range of 900 to 1,200 ℃ for 0.5 to 6 hours.

[0151] Alternatively, the magnetization roasting step (S600) according to the present invention may be performed by mixing 1.0 to 3.0 equivalents of graphite, coal and coke, and biomass as a reducing agent with titanium ore (100 weight parts) and heating the titanium ore mixture by irradiating it with microwaves having a single magnetron output range of 1 kW to 100 kW and a frequency of 915 MHz to 2.45 GHz for 5 to 60 minutes.

[0152] According to the magnetization roasting step (S600), iron-containing titanium minerals such as titanomagnetite, ulbospinel, and ilmenite can be obtained as magnetization roasting products.

[0154] Next, in order to improve magnetic separation efficiency (i.e., improvement of yield and grade of concentrate), a crushing step (S700) for separating the magnetized roasting product from the magnetized roasting step (S600) into individual parts may be performed again, and the particle size (D) of the crushed material obtained in this crushing step (S700) 90 It is preferable that ) be 200 mesh (74 μm) or less.

[0155] Since particle sizes outside the aforementioned range may be economically disadvantageous or have negative effects in subsequent processes, the particle size within the aforementioned range is most desirable.

[0157] Finally, a magnetic separation step (S800) may be performed, and it is most preferable that the magnetic strength in this magnetic separation step (S800) be in the range of 3,000 to 12,000 Gauss.

[0158] In addition, the magnetic product recovered from the magnetic separation step (S600) may be a magnetic mineral (i.e., concentrate) such as titanomagnetite and ilmenite, which are iron-containing titanium minerals, and ulbospinel, and metallic iron.

[0160] It should be noted that titanium concentrate can be recovered according to the beneficiation method for producing titanium concentrate from low-grade titanium ore according to the present invention, after undergoing all the steps of Fig. 3.

[0162] Figure 4 (a) is a diagram showing the magnetic separation results of iron-containing titanium minerals produced by magnetizing and roasting titanium ore in the Myeonsan Formation in the Taebaek region, and Figure 4 (b) is a diagram showing the results of magnetic separation of minerals that can be formed by magnetizing and roasting rutile and hematite, which are constituent minerals within the Myeonsan Formation, by actually synthesizing them with reagents.

[0163] Since metallic iron and magnetite are ferromagnetic materials, more than 90% is recovered even with a low magnetic strength of 1,000 Gauss.

[0164] Next, titanomagnetite, which can be formed by the reaction of rutile and hematite through magnetization roasting, is recovered at a rate of over 90% at 8,000 Gauss and over 10,000 Gauss, while ilmenite is recovered at a rate of over 70% at 12,000 Gauss and over. In the case of ulvospinel, a recovery rate of about 70% is shown at 12,000 Gauss and over.

[0165] However, hematite contained in the titanium ore of the Myeonsan Formation in the Taebaek region is recovered at less than 30% even with a strong magnetic force of 12,000 Gauss, and rutile is hardly recovered even with 12,000 Gauss.

[0166] Therefore, it was determined that in order to synthesize titanium minerals from titanium ore of the Myeonsan Formation in the Taebaek region through magnetization roasting, it is desirable to first form titanomagnetite and ilmenite.

[0167] This is because increasing magnetic strength is necessary to recover materials with low magnetic sensitivity; however, if magnetic strength is increased to raise the yield of titanium oxide, gangue minerals are also mixed in and become part of the magnetic compound, thereby lowering the grade of titanium oxide. Consequently, it may be necessary to add numerous magnetic processes in subsequent stages to remove gangue minerals and improve the grade of titanium oxide, which should be noted as being economically disadvantageous.

[0169] <Example 2> Mineralogical Characteristics of Titanium-Containing Ore Deposited in the Myeonsan Formation of the Taebaek Region

[0170] Figure 5 is a diagram showing the results of X-ray diffraction analysis of different types of titanium ore from the Myeonsan Formation in the Taebaek region used in the present invention, showing the XRD analysis results of relatively high-grade titanium ore from the outcrop portion collected from the Myeonsan Formation in the Taebaek region and low-grade borehole samples actually collected by drilling.

[0172] Table 3 below shows the chemical composition of relatively high-grade titanium ore from an outcrop section collected from the Myeonsan Formation in the same Taebaek region and low-grade borehole samples obtained by drilling.

[0173] Titanium ore contains mainly rutile and hematite as useful minerals, and quartz, muscovite, and clinochlore as gangue minerals.

[0174] However, as can be seen from Figure 5 and Table 3, the grade of TiO2 in titanium ore collected from the outcrop is as high as 25%, but when the chemical composition of a sample (average width; 60 m) obtained by drilling the Myeonsan Formation in the Taebaek region was analyzed, it was revealed that the average grade of TiO2 in titanium ore from the Myeonsan Formation in the Taebaek region was low, at approximately 8%.

[0175] Therefore, in order to ensure economic feasibility for the development of titanium mines in the Myeonsan Formation, it is necessary to increase the yield and grade of titanium oxide from low-grade titanium ore.

[0177]

[0179] Meanwhile, Table 4 below shows the results of XRD analysis for each particle size and the chemical composition analysis of the low-grade titanium ore from the Myeonsan Formation in the Taebaek region used in the present invention, which was crushed to 1 mm or less using a jaw crusher-concrete crusher-fin mill and then sieved.

[0180] As can be seen from Table 4, the chemical composition and XRD analysis results showed that iron oxide (Fe2O3) and titanium oxide (TiO2) components were somewhat high in the +35 mesh, but these iron oxide and titanium oxide components did not show a phenomenon of concentration in specific aggregates, which was determined to be because rutile and hematite were evenly mixed in a constant ratio throughout the aggregates.

[0181] Therefore, as can be seen from Table 4, it was determined that it would be somewhat difficult to improve the grade by separating / separating rutile and hematite through separation (or classification) and specific gravity separation.

[0183]

[0185] Figure 6 is a diagram showing the SEM-EDS analysis results of a titanium ore flake from the Myeonsan Formation in the Taebaek region used in the present invention.

[0186] As can be seen from Figure 6, the host rock, ilmenite, was found to be physically mixed with rutile and hematite formed in an oxidizing atmosphere, and the crystal size of the mixture was found to be 30 μm or less.

[0187] This means that the size of each rutile and hematite mineral crystal contained in these mixed mineral crystals is smaller than 30 μm, so as a result, in order to separate the rutile and hematite into individual crystals, it was theoretically expected that a separation rate of about 90% or more could be achieved by grinding them to a size of about 1 / 60 (0.5 μm) of the maximum crystal size (30 μm).

[0189] FIG. 7 is a figure showing the XRD analysis results of a product separated by specific gravity using a shaking table from titanium ore of the Myeonsan Formation in the Taebaek region in the present invention, where the maximum crystal size (D) of the titanium ore 90 This is the result obtained by grinding ) to 30 μm or less and separating by specific gravity using a shaking table.

[0190] Here, the maximum determination size (D 90 It is desirable to understand that ) being 30 μm or less means that 90% of the powder particles have a particle size of less than 30 μm, and indicates the content of the powder particle group.

[0192] Meanwhile, as shown in Figure 7, the particles of the crushed material were too small to obtain the effect of the difference in specific gravity, so the amount recovered as concentrate was very small and most of it was lost as tailings.

[0193] In addition, as a comparative example, when low-grade titanium ore was crushed and flotation was performed, the ore particles were too small and the content of gangue minerals was too high, resulting in a slime coating phenomenon. Consequently, the fine quartz in the gangue minerals inhibited the flotation of hematite and rutile, making it almost impossible to recover the rutile and hematite.

[0194] Therefore, from these results, it was found that there are limitations in economically increasing the grade and yield of titanium oxide concentrate using traditional beneficiation methods, such as specific gravity separation and flotation separation, for titanium ore from the Myeonsan Formation in the Taebaek region. Accordingly, the inventors of the present invention have arrived at a method to increase the grade and yield of titanium oxide concentrate by magnetic separation utilizing magnetization roasting technology, as described above.

[0196] <Example 3> Magnetization and roasting characteristics of titanium-containing ore buried in the Myeonsan Formation in the Taebaek region

[0197] FIG. 8 is a diagram showing the X-ray diffraction analysis results of a product produced by magnetizing and roasting in an experimental electric furnace at 900°C with varying mixing ratios of low-grade titanium ore and graphite collected from the outcrop of the Myeonsan Formation in the Taebaek region in the present invention.

[0198] Generally, iron ore reacts sequentially as shown in the reaction equation below to finally be reduced to metallic iron.

[0199] 3Fe2O3 + CO → 2Fe3O4 + CO2 (Step 1)

[0200] Fe3O4 + CO → 3FeO + CO2 (Step 2)

[0201] FeO + CO → Fe + CO2 (Step 3)

[0202] Fe2O3 + 3CO → 2Fe + 3CO2[(1) + (2) + (3) = overall reaction equation]

[0203] At this time, if the reducing agent reacts 100% with the hematite and carbon components, 3 moles of C (carbon) are required for 1 mole of Fe2O3.

[0204] When converted to a weight ratio, approximately 22.54 weights of carbon components are required for every 100 weights of hematite.

[0205] Therefore, Figure 8 shows that when the mixing amounts of hematite and graphite contained in low-grade titanium ore are varied from 0.5 equivalents to 3 equivalents and magnetized and roasted, at 0.5 equivalents, some unreacted rutile is visible, but titanomagnetite and ilmenite begin to form, and at mixing ratios of 1.5 equivalents or more, most of the hematite and rutile react and change into titanomagnetite and ilmenite.

[0206] Therefore, it can be seen that the appropriate mixing ratio (equivalent ratio) for transforming hematite and rutile in titanium ore into titanomagnetite and ilmenite through magnetization roasting is 1.0 - 3.0.

[0207] It is most desirable to mix hematite and carbon in titanium ore at a ratio of 1.5 equivalents or more.

[0209] Figure 9 shows the results of XRD analysis of the product obtained by mixing titanium ore from the Myeonsan Formation in the Taebaek region with 1.5 equivalents of graphite, a reducing agent, placing the mixed sample into a graphite crucible, closing the lid to set the atmosphere to a reducing state, and then magnetizing and roasting it in an experimental electric furnace at each firing temperature (800 ℃, 950 ℃, 900 ℃, 1000 ℃, 1050 ℃, 1100 ℃, and 1150 ℃) for 2 hours.

[0210] As shown in Fig. 9, the results of XRD analysis of the reduction roasting product revealed that in the temperature range of 850 to 1,000 ℃, the Free-TiO2 component was entirely converted into Titanomagnetite (2FeO·3Fe2O3·TiO2) and Ilmenite (FeO·TiO2) through the reaction of hematite (Fe2O3) and rutile (TiO2).

[0211] In addition, at temperatures above 1,050 ℃, Psuedobrookite (Fe2O3·TiO2), rutile (TiO2), and metallic iron are produced, while Quartz (SiO2), the main mineral of gangue minerals, remains in an unreacted state.

[0212] Therefore, when titanium ore is mixed with a reducing agent and magnetized and roasted in a temperature range of 850 to 1,000 ℃, Quartz (SiO2) remains unreacted, and rutile reacts with hematite to transform into Titanomagnetite (2FeO·3Fe2O3·TiO2) and Ilmenite (FeO·TiO2), which have high magnetic sensitivity, and it can be seen that both the titanium and iron components in the ore are combined.

[0213] However, magnetized roasting products generated at temperatures above 1,050 ℃ exhibit a phenomenon of decomposing back into metallic iron with high magnetic sensitivity and non-magnetic TiO2.

[0214] Therefore, when a mixture of titanium ore and graphite is magnetized and roasted within a temperature range of 850 to 1,000 °C, it is transformed into iron-containing titanium minerals with high magnetic sensitivity, such as Titanomagnetite (2FeO·3Fe2O3·TiO2) and Ilmenite (FeO·TiO2). As mentioned above in relation to Figure 4, if the magnetized roasting product composed of iron-containing titanium minerals is finely ground and separated into individual components, and then magnetically separated, it is expected that iron-containing titanium minerals containing titanium oxide components can be easily recovered, and thus the recovery rate of titanium oxide can be improved.

[0216] FIGS. 10(a) and FIGS. 10(b) show the X-ray diffraction analysis results of the magnetic concentrate and magnetic tailings recovered by wet magnetic separation at 8,000 Gauss of the product obtained by mixing low-grade titanium ore from the Myeonsan Formation in the Taebaek region and graphite at a mixing ratio of 1.5 equivalents in the present invention and magnetizing and roasting it in an experimental electric furnace at 900 °C. As already confirmed from FIG. 9 mentioned above, the low-grade titanium ore from the Myeonsan Formation in the Taebaek region and a reducing agent were mixed at a ratio of 1.5 equivalents, and then this mixed sample was placed in a graphite crucible, the lid was closed to set the atmosphere to a reducing state, and the product was magnetized and roasted in an experimental electric furnace for 2 hours at each calcination temperature (900 °C, 925 °C, 950 °C, 975 °C, 1000 °C, 1050 °C, and 1100 °C) to obtain The results of analyzing magnetic and non-magnetic products recovered by magnetic separation with a magnetic force of 8000 Gauss using XRD are shown.

[0218] As can be seen from Figures 10(a) and 10(b), as a result of magnetic separation, iron-containing titanium minerals such as Titanomagnetite (2FeO·3Fe2O3·TiO2) and Ilmenite (FeO·TiO2) were mostly recovered as magnetic products, and quartz minerals such as gangue minerals were mainly found as non-magnetic products.

[0220] In addition, as shown in Table 5 and Figure 11 below, the yield and chemical composition of the magnetite concentrate and magnetite tailings were analyzed to confirm the grade and yield of titanium oxide and iron oxide, respectively.

[0221] Figure 11 is a diagram showing the grade and yield of magnetic concentrate recovered by mixing low-grade titanium ore and graphite from the Myeonsan Formation in the Taebaek region at a mixing ratio of 1.5 equivalents in the present invention, mixing the resulting product at different temperatures, grinding the product, and separating it by wet magnetic force at 8,000 Gauss.

[0223]

[0225] As can be seen from Table 5 and Figure 11 above, the grades of titanium oxide and iron oxide in the magnetically separated concentrate without magnetization roasting were 15.2% and 30.5%, respectively, and the yields were very low at 45.0% and 52.4%, respectively. However, in the magnetization roasting temperature range of 925 to 975 ℃, the grades of titanium oxide and iron oxide increased to 28.8 to 30.9% and 55.0 to 57.5%, respectively, and the yields increased to 90.1 to 90.0% and 90.2 to 93.8%, respectively.

[0226] On the other hand, when magnetized and roasted at a temperature of 1,000 ℃ or higher, the quality and yield of titanium oxide and iron oxide actually decreased.

[0227] It is believed that this phenomenon is due to the fact that at temperatures above 1,000°C, as confirmed by Figure 9 above, iron-containing titanium minerals decompose into metallic iron and rutile, so the yield of iron components with high magnetic sensitivity increases and the yield of rutile decreases.

[0228] Therefore, the optimal magnetization roasting temperature to simultaneously increase the quality and yield of titanium oxide and iron oxide is most preferably 900 to 1,000 ℃.

[0230] <Example 4> Microwave Heating, Magnetization Roasting, and Magnetic Separation Characteristics of Low-Grade Titanium-Containing Ore Deposited in the Myeonsan Formation of the Taebaek Region

[0231] Figure 12 is a diagram showing the X-ray diffraction analysis results of a product prepared by varying the microwave irradiation time in an experimental microwave heating furnace using a material mixed with low-grade titanium ore and graphite from the Myeonsan layer of the Taebaek region in a mixing ratio of 1.5 equivalents (3C / Fe2O3 = 1 equivalent) in the present invention.

[0232] Figure 12 shows the XRD analysis results of a magnetized roasted product prepared by mixing titanium ore and graphite from the Myeonsan Formation in the Taebaek region in 1.5 equivalents (3C / Fe2O3 = 1 equivalent) according to the optimal mixing conditions for magnetization roasting confirmed in Figure 8 above, placing the material (120 g) into a material crucible, and varying the microwave irradiation time in an experimental microwave heating furnace (output: 3 kW).

[0233] As can be seen from Figure 12, the results of XRD analysis of the obtained reduction roasting product showed that when the microwave irradiation time was in the range of 10 to 60 minutes, most of the hematite (Fe2O3) and rutile (TiO2) in the ore reacted to transform into titanium magnetite (2FeO·3Fe2O3·TiO2), ilmenite (FeO·TiO2), and metallic iron.

[0234] When microwaves with a power of 100 V and 0.5 A (50 W) are irradiated, the temperature rises within about 5 minutes and reaches a peak, and the temperature of the magnetized roasted product during a heating time of about 10 to 60 minutes is maintained in the range of 950 to 1,000℃.

[0235] That is, it can be seen that it has a similar firing temperature when compared to the characteristics of the magnetized roasting products according to the magnetized roasting temperature in the above-mentioned Fig. 9.

[0236] Therefore, it was confirmed that when graphite is mixed with titanium ore in an amount of 1.0 to 3.0 equivalents (3C / Fe2O3 = 1 equivalent) and microwaves are irradiated for more than 10 minutes, the titanium oxide components in the ore are mostly altered into iron-containing titanium minerals with high magnetic sensitivity, namely Titanomagnetite (2FeO·3Fe2O3·TiO2) and Ilmenite (FeO·TiO2).

[0238] FIGS. 13a and 13b show a product prepared in the present invention by varying the microwave irradiation time in an experimental microwave heating furnace by mixing a material in which low-grade titanium ore from the Myeonsan Formation in the Taebaek region and graphite are mixed at a ratio of 1.5 equivalents (3C / Fe2O3 = 1 equivalent), and then grinding (D) the product to separate it into individual components. 90 This is a diagram showing the X-ray diffraction analysis results of magnetic concentrate and magnetic tailings recovered by wet magnetic separation at 8,000 Gauss after (30 μm).

[0240] From FIGS. 13a and 13b, similar to the magnetic separation experiment results of FIG. 10 mentioned above, it can be seen that iron-containing titanium minerals such as Titanomagnetite (2FeO·3Fe2O3·TiO2) and ilmenite (FeO·TiO2) are mostly recovered as magnetic products, and gangue minerals such as quartz are mainly present as non-magnetic products.

[0242] FIG. 14 shows a product prepared by varying the microwave irradiation time in an experimental microwave heating furnace by mixing low-grade titanium ore from the Myeonsan Formation in the Taebaek region and graphite at a mixing ratio of 1.5 equivalents (3C / Fe2O3 = 1 equivalent) in the present invention, and then grinding (D) the product to separate it into individual components. 90 This is a diagram showing the yield and grade of magnetic concentrate recovered by wet magnetic separation at 8,000 Gauss after (30 μm).

[0243] FIG. 14 shows the particle size (D) of the product magnetized and roasted using microwaves so that it can be separated into individual particles. 90 This shows the grade and recovery rate of titanium oxide and iron oxide, respectively, by analyzing the yield and chemical composition of the recovered magnetic concentrate and magnetic tailings after finely grinding the material to 30 μm or less and then wet-magnifying them.

[0245] From Table 6 and Figure 14 below, it can be seen that as a result of magnetic separation of the raw ore that was not magnetized and roasted, the grades of titanium oxide and iron oxide in the magnetized concentrate were 12.0% and 28.1%, respectively, and the yields were very low, at approximately 17.1% and 48.1%, respectively.

[0246] However, as a result of magnetizing and roasting by irradiating with microwaves for 10 to 60 minutes, it can be seen that the grades of titanium oxide and iron oxide increased significantly to 28.6 to 31.5% and 55.1 to 65.1%, respectively, and the yields increased significantly to 82.5 to 91.2% and 88.5 to 93.1%, respectively.

[0247] Therefore, the magnetization roasting time by microwave heating to simultaneously increase the quality and yield of titanium oxide and iron oxide is preferably 5 to 60 minutes, and it is determined that performing microwave heating for 10 minutes or more is most desirable.

[0249]

[0251] 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 modified in various ways or equivalent embodiments can be carried out based on the above description.

[0252] 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. Explanation of the symbols

[0254] S100: Titanium Ore Preparation Step S200: Crushing stage S300: Heavy chain stage S400: Sieve separation stage S500: Reducing agent and mixing step S600: Magnetization roasting stage S700: Grinding stage S800: Magnetic separation stage

Claims

Claim 1 A beneficiation method for producing titanium concentrate from low-grade titanium ore, comprising: (a) a step of crushing / heavy-crushing low-grade titanium ore; (b) a step of sieving the crushed / heavy-crushed material; (c) a step of mixing the sieved material with a reducing agent; (d) a step of magnetizing and roasting the mixture of the crushed material and the reducing agent; (e) a step of crushing the magnetized and roasted product to separate it into individual components; and (f) a step of wet magnetic separation of the crushed magnetized and roasted product; wherein coal, coke, and biomass are mixed as a reducing agent in an amount of 1.0 to 3.0 equivalents (3C / Fe2O3 = 1 equivalent) to the titanium ore in step (c), and the magnetizing and roasting in step (d) is characterized by magnetizing and roasting the mixture of titanium ore and the reducing agent in a furnace at a temperature range of 900 to 1,200 ℃ for 0.5 to 6 hours. Claim 2 A method for producing titanium concentrate from low-grade titanium ore according to claim 1, characterized in that the titanium ore in step (a) is composed of sedimentary rock containing hematite (Fe2O3) and rutile (TiO2). Claim 3 In claim 1, the particle size (D) of the ore separated in the step of sieving the crushed / heavy-crushed ore of steps (a) and (b). 90 A beneficiation method for producing titanium concentrate from low-grade titanium ore, characterized by having a diameter of 5 mm or less. Claim 4 delete Claim 5 delete Claim 6 A method for producing titanium concentrate from low-grade titanium ore according to claim 1, wherein the magnetization roasting in step (d) is characterized by heating a titanium ore mixture by irradiating it with microwaves having a single magnetron output range of 1 kW to 100 kW and a frequency of 915 MHz to 2.45 GHz for 5 to 60 minutes. Claim 7 A method for producing titanium concentrate from low-grade titanium ore, characterized in that, in claim 1, the magnetization roasting product of step (d) is titanomagnetite, ulbospinel, and ilmenite, which are iron-containing titanium minerals. Claim 8 In claim 1, in the grinding step of the magnetized roasting product of step (e), the particle size (D of the ground material) 90 A beneficiation method for producing titanium concentrate from low-grade titanium ore, characterized by the mesh size being 200 mesh (75 μm) or less. Claim 9 A beneficiation method for producing titanium concentrate from low-grade titanium ore, characterized in that, in the magnetic separation step of the crushed magnetized roasting product of step (f) according to claim 1, the magnetic strength has a range of 3,000 to 12,000 Gauss. Claim 10 A method for producing titanium concentrate from low-grade titanium ore, characterized in that, in claim 1, the magnetic product recovered by magnetic separation in step (f) is iron-containing titanium minerals such as titanomagnetite and ilmenite, ulbospinel, and metallic iron. Claim 11 Titanium concentrate characterized by being recovered by a beneficiation method for producing titanium concentrate from low-grade titanium ore according to any one of claims 1 to 3 and claims 6 to 10.

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