Efficient utilization method of micro-fine particle disseminated high-silicon refractory ore
By performing weak-magnetic-strong magnetic separation under the dissociation of high-silicon hard-to-sorted grinding monomers reaching 60-80%, and combining oxidation and roasting and blast furnace ironmaking technology, the problem of difficult to efficiently utilize high-silicon hard-to-sorted resources in fine-grained embedded high-silicon hard-to-sorted ore resources is achieved economic and efficient utilization.
Patent Information
- Application Number
- CN202510033529.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-01-09
- Publication Date
- 2025-03-28
AI Technical Summary
The prior art is difficult to economically and efficiently utilize the high silicon difficult ore resources for fine-grained embedded fabrics, mainly because of their fine embedded fabrics, resulting in high grinding cost.
Under the condition that the dissociation degree of the grinding monomer of high-silicon difficult to dissect ore reaches 60-80%, weak magnetic-strong magnetic separation operation is carried out to obtain low-iron high-silicon concentrate, and acidic oxidized pellets are prepared through oxidation and roasting, and combined with blast furnace iron smelting technology to achieve efficient utilization of resources.
The economical and efficient use of fine-grained embedded high-silicon difficult-to-sed ore is achieved, reducing the cost of ratio and ore dressing, and improving the metal recovery and resource utilization of iron.
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Figure CN119710226A_ABST
Abstract
Description
Technical Field
[0001] The invention belongs to the technical field of metallurgy, and in particular relates to a method for efficiently utilizing fine-grained high-silicon refractory ore. Background Art
[0002] my country is a country with relatively rich iron ore resources in the world, but there is a shortage of resources available for development and utilization. my country's iron ore resources generally present the following characteristics: First, the grade of iron ore resources is low. As of the end of 2021, the average grade of domestic iron ore is only 34.50%, which is much lower than that of Brazil, Russia, India and other countries, and also lower than the world average iron ore grade; second, there are more poor mines and fewer rich mines, and the reserves of poor ore resources account for 80% of the total reserves; third, there are more small and medium-sized mines, and fewer large and extra-large mines; fourth, the ore types are complex, and there are many iron ores that are difficult to use.
[0003] Based on the current resource status of my country's iron ore with low average grade, high proportion of poor ore and great difficulty in ore utilization, in addition to vigorously prospecting for ore, the use of technical means to improve the comprehensive utilization level of difficult-to-select and difficult-to-utilize iron ore is also an important means to increase my country's iron ore self-sufficiency rate and reduce dependence on foreign countries.
[0004] High silicon ore is a typical type of iron ore that is difficult to select and utilize. It is widely distributed in China, but its utilization rate is generally low. The main reason is that high silicon ore is generally fine-grained, resulting in high grinding and selection costs. Therefore, it is not economical to use conventional iron ore beneficiation ideas to treat fine-grained high silicon refractory ore. In order to achieve the purpose of economically utilizing fine-grained high silicon refractory ore resources, a new way to efficiently utilize fine-grained high silicon refractory ore is proposed. Summary of the invention
[0005] Aiming at the problem that fine-grained high-silicon refractory ores are difficult to utilize economically and efficiently, the present invention conducts weak magnetic-strong magnetic separation operations under the condition that the degree of dissociation of grinding monomers of high-silicon refractory ores reaches 60-80%, so as to obtain low-iron high-silicon concentrate. The low-iron high-silicon concentrate is oxidized and roasted to obtain acidic oxidized pellets, which are added to high-alkalinity sintered ore in a blast furnace for ironmaking operations, thereby achieving the purpose of economically and efficiently utilizing the resources of fine-grained high-silicon refractory ores.
[0006] To achieve the above object, the present invention adopts the following technical solution: A method for efficiently utilizing fine-grained high-silicon refractory ore, comprising the following steps: 1) Crushing-grinding: The fine-grained high-silicon refractory ore is first crushed to less than 15mm by the crushing system. The crushed ore is processed by the grinding system to obtain the selected ore with qualified fineness. The grinding fineness is -200 mesh accounting for 85%~90%, -300 mesh accounting for 70%~85%. At this time, the dissociation degree of iron mineral monomers is 60%~80%, and the proportion of iron minerals coexisting with gangue minerals is 20%~40%; 2) Weak magnetic-strong magnetic separation: The selected raw ore with qualified fineness is separated by weak magnetic separation to obtain weak magnetic concentrate and middlings, and the middlings are separated by strong magnetic separation to obtain strong magnetic concentrate and tailings. The weak magnetic concentrate and strong magnetic concentrate are combined to obtain low iron and high silicon concentrate; 3) Oxidation roasting: The oxidation roasting operation adopts one of the chain grate-rotary kiln-ring cooler process, the belt roasting machine process or the vertical furnace oxidation roasting process. The roasting raw materials are selected according to the characteristics of other charges of the local steel enterprise. When other charges are high-alkalinity charges, high-acidity oxidized pellets are prepared by roasting low-iron and high-silicon concentrate alone or by adding high-proportion low-iron and high-silicon concentrate to low-proportion high-iron and low-silicon concentrate. When other charges are low-alkalinity charges, low-acidity oxidized pellets are prepared by adding high-proportion high-iron and low-silicon concentrate to low-proportion low-iron and high-silicon concentrate.
[0007] Furthermore, the distribution of fine-grained high-silicon refractory ore is extremely fine, with iron minerals with a particle size of 15-50μm accounting for 60-80%. The iron minerals are mainly magnetite and hematite, with a small amount of limonite and siderite, and occasionally pyrite. The iron grade of the original ore is 25-35%.
[0008] Furthermore, the grinding fineness of the raw ore selected by the weak magnetic-strong magnetic separation system is -200 mesh accounting for 85-95%, and -300 mesh accounting for 70-85%. At this time, the dissociation degree of iron mineral monomers is 60-80%, and the proportion of iron minerals coexisting with gangue minerals is 20-40%.
[0009] Furthermore, in the weak magnetic-strong magnetic separation operation, the equipment used for weak magnetic separation is a roller magnetic separator, the field strength of the magnetic separator is 200-300mT, the iron grade of the weak magnetic concentrate is 52-58%, and the SiO2 content is 10-15%; the strong magnetic separation equipment used is a vertical ring strong magnetic separator, the field strength of the magnetic separator is 600-1000mT, the grade of the strong magnetic concentrate is 45-50%, and the SiO2 content is 20-25%. After the strong magnetic concentrate and the weak magnetic concentrate are combined, a low iron and high silicon concentrate with an iron grade of 48-55% and a SiO2 content of 16-22% is obtained.
[0010] Furthermore, for weak magnetic-strong magnetic separation operations, the process design changes according to the difference in the properties of the original ore. When the high-silicon difficult-to-separate iron minerals are mainly magnetite, the separation operation adopts a separate weak magnetic separation process.
[0011] Furthermore, in blast furnace ironmaking operations, iron oxides in the acidic oxidation pellets provide iron for the ironmaking operation, and SiO2 can be used to adjust the basicity of the charge entering the furnace.
[0012] The present invention has the following beneficial effects: 1. A new way to efficiently utilize fine-grained high-silicon refractory ore has changed the quality standard of iron concentrate. The ore dressing product has been adjusted to a low-iron, high-silicon concentrate with an iron grade of 48-55% and a SiO2 content of 16-22%, which reduces the selection ratio, increases the metal recovery rate of iron, and has a higher resource utilization rate; 2. A new way to efficiently utilize fine-grained high-silicon refractory ores. By changing the quality standard of iron ore concentrate, the selection ratio is greatly reduced, and the beneficiation cost is greatly reduced. The economic efficiency of such iron ore disposal is significantly improved, achieving the purpose of effectively utilizing fine-grained high-silicon refractory ores; 3. The iron and silicon in high-silicon refractory ores are used as valuable elements. Iron provides ferrite for blast furnace smelting, and SiO2 can be used to adjust the basicity of the charge entering the furnace. The proportion of valuable components of iron and silicon in the concentrate is higher than 70%. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] Figure 1 It is a flow chart of the mineral processing process of the present invention. DETAILED DESCRIPTION
[0014] The present invention is further explained below with reference to specific embodiments.
[0015] Example 1 A domestic fine-grained high-silicon refractory ore was used for processing. The iron mineral particle size of 15-50μm accounted for 70%. Among the mineral composition, magnetite accounted for 85%, hematite accounted for 15%, and the rest were limonite, siderite and pyrite. The iron grade of the original ore was 28%.
[0016] (1) Crushing of fine-grained high-silicon refractory ores: The high-silicon refractory ores mined from mines are crushed to less than 15 mm by a crushing system. The crushed ores are processed by a grinding system to obtain the selected raw ores with qualified fineness. The grinding fineness is -200 mesh, accounting for 90%, and -300 mesh, accounting for 78%. At this time, the dissociation degree of iron mineral monomers is 75%.
[0017] (2) The raw ore was separated by weak magnetic separation to obtain a low-iron, high-silicon concentrate with an iron grade of 52% and a SiO2 content of 18%. The iron metal recovery rate was 85% and the beneficiation ratio was 2.5 times.
[0018] (3) Oxidation roasting: According to the local blast furnace material requirements, pellets with an SiO2 content of less than 6% are required. Acidic oxidized pellets are prepared by roasting low-iron high-silicon concentrate with high-iron low-silicon concentrate. The selected high-iron low-silicon concentrate has an iron grade of 65% and an SiO2 content of 2%. The pellets are roasted in a ratio of 2:8 between low-iron high-silicon concentrate and high-iron low-silicon concentrate. The oxidized pellets prepared by roasting have an iron grade of 62.4% and an SiO2 content of 5.2%. The compressive strength is 2600N / ball, the pellet reduction index is 82%, and the pellet reduction expansion index is 13.5%, which meets the quality requirements for pellets entering the furnace.
[0019] (4) Blast furnace ironmaking: Based on the comprehensive basicity requirements of the blast furnace charge and the composition of the pellets, sintered ore and flux, the appropriate ratio of acidic pellets and high-basicity sintered ore is determined and the blast furnace is charged with the appropriate ratio for smelting.
[0020] Example 2 Example 1 was repeated, except that during oxidative roasting, high-acidity oxidized pellets were provided according to the local blast furnace material requirements, and low-iron and high-silicon concentrate was roasted separately. The prepared high-acidity oxidized pellets had an iron grade of 51.5%, a SiO2 content of 18.6%, a compressive strength of 2350 N / ball, a pellet reduction index of 78%, and a pellet reduction expansion index of 12.8%.
[0021] Example 3 Example 1 was repeated, except that in the mineral composition, magnetite accounted for 60%, hematite accounted for 35%, and the rest were limonite, siderite and pyrite. The raw ore was preliminarily selected by weak magnetic separation to obtain weak magnetic concentrate and medium ore. The medium ore was selected by strong magnetic separation and scanning to obtain strong magnetic concentrate. The weak magnetic concentrate and the strong magnetic concentrate were combined to obtain a low-iron and high-silicon concentrate with an iron grade of 51% and a SiO2 content of 19%. The low-iron and high-silicon concentrate was oxidized and roasted separately to obtain a high-acidity oxidized pellet with an iron grade of 50.5%, a SiO2 content of 19.5%, a compressive strength of 2230N / ball, a pellet reduction index of 78%, and a pellet reduction expansion index of 13.2%.
Claims
1. A method for efficiently utilizing fine-grained high-silicon refractory ore, characterized in that: The following steps are involved: 1) Crushing-grinding: The fine-grained high-silicon refractory ore is first crushed to less than 15mm by the crushing system. The crushed ore is processed by the grinding system to obtain the selected ore with qualified fineness. The grinding fineness is -200 mesh accounting for 85%~90%, -300 mesh accounting for 70%~85%. At this time, the dissociation degree of iron mineral monomers is 60%~80%, and the proportion of iron minerals coexisting with gangue minerals is 20%~40%; 2) Weak magnetic-strong magnetic separation: The selected raw ore with qualified fineness is separated by weak magnetic separation to obtain weak magnetic concentrate and middlings, and the middlings are separated by strong magnetic separation to obtain strong magnetic concentrate and tailings. The weak magnetic concentrate and strong magnetic concentrate are combined to obtain low iron and high silicon concentrate; 3) Oxidation roasting: The oxidation roasting operation adopts one of the chain grate-rotary kiln-ring cooler process, the belt roasting machine process or the vertical furnace oxidation roasting process. The roasting raw materials are selected according to the characteristics of other charges of the local steel enterprise. When other charges are high-alkalinity charges, high-acidity oxidized pellets are prepared by roasting low-iron and high-silicon concentrate alone or by adding high-proportion low-iron and high-silicon concentrate to low-proportion high-iron and low-silicon concentrate. When other charges are low-alkalinity charges, low-acidity oxidized pellets are prepared by adding high-proportion high-iron and low-silicon concentrate to low-proportion low-iron and high-silicon concentrate.
2. A method for efficiently utilizing fine-grained high-silicon refractory ore as claimed in claim 1, characterized in that: In step 1), the fine-grained high-silicon iron minerals with a particle size of 15-50 μm account for 60-80%, the iron minerals are mainly magnetite and hematite, and the iron grade of the original ore is 25%-35%.
3. A method for efficiently utilizing fine-grained high-silicon refractory ore as claimed in claim 1, characterized in that: In step 2), the equipment used for the weak magnetic separation is a roller magnetic separator, the magnetic separator field strength is 200~300mT, the weak magnetic concentrate has an iron grade of 52%~58%, and the SiO2 content is 10%~15%; the strong magnetic separation equipment used is a vertical ring strong magnetic separator, the magnetic separator field strength is 600~1000mT, the strong magnetic concentrate has a grade of 45%~50%, and the SiO2 content is 20%~25%; the strong magnetic concentrate and the weak magnetic concentrate are combined to obtain a low iron and high silicon concentrate with an iron grade of 48%~55% and a SiO2 content of 16%~22%.
4. A method for efficiently utilizing fine-grained high-silicon refractory ore as claimed in claim 1, characterized in that: In step 3), the iron grade of the high-iron low-silicon concentrate is 60%-75%, and the SiO2 content is 1%-5%; the added amount is 20%-80% of the mass of the low-iron high-silicon concentrate.