Process for directly preparing boiling chlorination furnace charge through ilmenite concentration-electric furnace smelting

Abstract

The process comprises the following steps that S1, element distribution state analysis is conducted on ilmenite concentrates in different areas, and the ilmenite concentrates with the magnesium element content lower than 0.5% in the ilmenite phase are selected as raw materials for concentration; s2, the ilmenite concentrate selected in the step S1 is subjected to ore grinding treatment and then subjected to concentration and impurity removal, and high-quality ilmenite concentrate is obtained; and S3, the high-quality titanium concentrate obtained in the S2 is smelted through an electric furnace, and high-titanium slag meeting the boiling chlorination furnace burden requirement is obtained. The high-titanium slag obtained by smelting the high-quality titanium concentrate through the electric furnace does not need to be subjected to impurity removal treatment, qualified fluidizing chlorination furnace charge can be obtained, the impurity removal cost of the beneficiation method is low, the process is short, safe supply of raw materials for fluidizing chlorination production in China is guaranteed, and the method has important significance in promoting development of the titanium industry in China.

Description

Technical Field

[0001] The invention belongs to the field of ilmenite utilization, and specifically relates to a process for directly preparing boiling chlorination furnace charge by ilmenite concentration-electric furnace smelting. Background Art

[0002] Titanium dioxide is the best white pigment and is included in the national strategic resource reserve. Titanium concentrate is a mineral resource selected from ilmenite or vanadium-titanium magnetite. It is the raw material for the production of titanium dioxide, sponge titanium, titanium slag and other titanium products. Since the 21st century, my country's titanium industry has entered a stage of rapid development. Its production capacity and output have ranked first in the world for many consecutive years. At present, the output of sponge titanium accounts for 60% of the world's total output. The output of titanium processed materials has grown steadily, and the demand for titanium products is strong. my country has become a veritable world titanium industry power. In 2022, my country's titanium concentrate output reached 7.45 million tons. However, part of my country's ilmenite resources are high-calcium-magnesium-titanium resources. Titanium dioxide is mainly prepared by sulfuric acid method, which has serious environmental pollution problems. High-calcium-magnesium-titanium resources cannot meet the raw material requirements of boiling chlorination method for producing high-end titanium products. Some high-quality titanium concentrates need to be imported, which poses a risk to resource security. Therefore, how to efficiently utilize my country's iron concentrate resources is of great significance to promoting the development of the titanium industry and ensuring national security.

[0003] At present, the methods for preparing boiling chlorination charge from titanium concentrate are mostly to remove impurities from the high-titanium slag obtained from the smelting of titanium concentrate, such as the Canadian UGS slag preparation process, which has the problems of long process, high acid consumption, high cost, serious pollution, etc. Therefore, in view of the current problems of long process and high cost in the preparation of boiling chlorination charge from titanium concentrate, the purpose of the present invention is to provide a process for directly preparing boiling chlorination charge from titanium concentrate by beneficiation of titanium concentrate and electric furnace smelting, so as to improve the utilization level of my country's titanium resources, ensure resource safety, and promote the sustainable development of my country's titanium industry. Summary of the invention

[0004] In view of the problems of long process and high cost in the preparation of boiling chlorination charge from titanium concentrate at present, the purpose of the present invention is to provide a process for preparing boiling chlorination charge from titanium concentrate by beneficiation and electric furnace smelting, so as to improve the utilization level of titanium resources in my country, ensure resource safety and promote the sustainable development of my country's titanium industry.

[0005] The present invention provides the following technical solution: a process for preparing boiling chlorination furnace charge by titanium concentrate concentration-electric furnace smelting, comprising the following steps: S1 Analyze the element distribution state of ilmenite concentrates from different regions, and select ilmenite concentrates with a magnesium content of less than 0.5% by mass in the ilmenite mineral phase as raw materials for subsequent concentrating; S2 grinding the ilmenite concentrate selected in S1 and then beneficiating and removing impurities to obtain high-quality titanium concentrate; the mass percentage of MgO in the high-quality titanium concentrate is ≤0.5%; S3 The high-quality titanium concentrate obtained in S2 is smelted in an electric furnace to obtain high-titanium slag that meets the requirements of boiling chlorination furnace charge.

[0006] Preferably, it is characterized in that the analysis method of the element distribution state of ilmenite includes one or more of scanning electron microscopy-energy spectrum analysis, electron probe and the like.

[0007] In the present invention, the ilmenite with a magnesium content of less than 0.5% in the ilmenite mineral phase includes an ilmenite concentrate with an average magnesium content of less than 0.5% by mass in the non-gangue components. The present invention proposes for the first time that ilmenite with a magnesium content of less than 0.5% in the ilmenite mineral phase can be used as a preliminary raw material screening basis, and high-titanium slag that meets the requirements of boiling chlorination furnace charge can be quickly obtained in combination with subsequent selection and impurity removal. At the same time, the present invention provides the necessary conditions for quickly and stably obtaining high-titanium slag required for boiling chlorination furnace charge using ilmenite concentrate as raw material.

[0008] Preferably, it is characterized in that the ilmenite grinding method includes one or more of ball milling, high pressure roller milling, damp milling, vertical mill and the like; the ilmenite concentration and impurity removal method includes one or more of magnetic separation, flotation, gravity separation and the like.

[0009] Preferably, the selection and impurity removal comprises: grinding the ilmenite concentrate selected by S1 by a ball mill to a -200 mesh content of 70-95%, preferably 90%, and separating and removing impurities by flotation, selecting a collector of sodium oleate of 1000-2000 g / t, preferably 1200-1600 g / t, a depressant of water glass of 700-900 g / t, preferably 750-850 g / t, and a regulator of sulfuric acid of 800-1200 g / t, preferably 900-1100 g / t, and more preferably 1000 g / t, to obtain high-quality titanium concentrate.

[0010] Preferably, the selection and impurity removal comprises: grinding the ilmenite concentrate selected by S1 with a ball mill to a -200 mesh content of 70-95%, preferably 90%, and separating and removing impurities with a high gradient magnetic separator at a magnetic field strength of 0.2-0.5 T, a vertical ring speed of 5.5-6.5 r / min, preferably 6.0 r / min, a stroke of 11-13 mm, preferably 12 mm, and a stroke of 90-110 r / min, 100 r / min, to obtain high-quality titanium concentrate.

[0011] Preferably, in the high-quality titanium concentrate obtained in S2, TiO2≥46%, SiO2≤1.4%, MgO≤0.5%, and CaO≤0.18%, by mass percentage. In the present invention, MgO≤0.5wt% in the high-quality titanium concentrate must be strictly controlled, otherwise in S3, there will be a significant increase in magnesium oxide in the titanium slag, which will result in the product being unable to be directly used for boiling chlorination production after electric furnace smelting.

[0012] Preferably, in S3, the temperature of the electric furnace smelting is 1600-1750° C., and the smelting time is 1-3 hours.

[0013] Preferably, in the high-titanium slag obtained after smelting in an electric furnace, TiO2≥85%, SiO2≤2.5%, MgO≤1.0%, and CaO≤0.35%, calculated by mass percentage.

[0014] The advantages of the present invention are: The present invention proposes for the first time a process of first concentrating titanium concentrate and then adopting electric furnace smelting to directly prepare it to meet the requirements of boiling chlorination. The present invention attempts for the first time to select ilmenite with a magnesium element mass percentage of less than 0.5% in the ilmenite mineral phase as the target mineral through the distribution of mineral phase elements of ilmenite resources in different mining areas, and then adopts a re-concentration method to sort and remove impurities to MgO≤0.5wt% to obtain high-quality titanium concentrate with low calcium and magnesium. The high-titanium slag obtained by electric furnace smelting of the high-quality titanium concentrate does not need to be further treated with impurities removal and can be used as a qualified boiling chlorination furnace charge. The ore dressing method has low impurity removal cost and short process, which ensures the safe supply of raw materials for boiling chlorination production in my country, and is of great significance to promoting the development of my country's titanium industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is the SEM-EDS image of the raw titanium concentrate used in Examples 1 and 2. DETAILED DESCRIPTION

[0016] The specific embodiments of the present invention are further described below by way of examples, but the specific embodiments of the present invention are not limited to the following examples.

[0017] In the embodiment of the present invention, the main chemical components of the raw material ilmenite concentrate are (wt%): TiO2: 44.86%, SiO2: 3.32%, CaO: 1.32%, MgO: 1.45%, and the remainder is common oxides in ilmenite such as iron, aluminum, and manganese. Among the raw materials used, the content of magnesium oxide in the gangue is greater than 1.45%.

[0018] Example 1 A process for preparing boiling chlorination furnace charge by ilmenite concentrate selection-electric furnace smelting, comprising the following steps: S1 Scanning electron microscope-energy spectrum analysis was used to analyze the mineral phase of the ilmenite concentrate. Figure 1 This is the SEM-EDS image of the titanium concentrate used in the example. EDS points 54 and 58 are the elemental composition of the ilmenite mineral phase. It can be seen that the Mg content is 0.15% and 0.05%, which can be used for the next step of sorting.

[0019] S2 The ilmenite concentrate selected by S1 was ground by ball mill for 10 min, and the -200 mesh content reached 90.12%. Flotation was used for separation and impurity removal. The collector sodium oleate 1500g / t, the inhibitor water glass 800g / t, and the adjusting agent sulfuric acid 1000g / t were selected. The obtained high-quality titanium concentrate contained TiO2: 47.26%, SiO2: 0.92%, CaO: 0.16%, MgO: 0.41%, the titanium recovery rate was 85.69%, and the yield of high-quality titanium concentrate was 82.16%.

[0020] S3 The high-quality titanium concentrate obtained in S2 is smelted in an electric furnace at a smelting temperature of 1700°C for 2 hours to obtain high-titanium slag with TiO2: 89.26%, TFe: 4.89%, SiO2: 1.98%, CaO: 0.31%, and MgO: 0.79%, which can meet the requirements of boiling chlorination furnace charge.

[0021] After selecting ilmenite concentrate with a magnesium content of less than 0.5% by mass in the ilmenite mineral phase as the raw material for subsequent selection, the above steps S2 and S3 are repeated to continuously produce more than 100 tons of high-titanium slag that meets the requirements of boiling chlorination furnace charge.

[0022] Example 2 A process for preparing boiling chlorination furnace charge by ilmenite concentrate selection-electric furnace smelting, comprising the following steps: S1 Scanning electron microscope-energy spectrum analysis was used to analyze the mineral phase of the titanium concentrate. Figure 1 This is the SEM-EDS image of the titanium concentrate used in the example. EDS points 54 and 58 are the elemental composition of the ilmenite mineral phase. It can be seen that the Mg content is 0.15% and 0.05%, which can be used for the next step of sorting.

[0023] S2 The titanium concentrate selected by S1 was ground in a ball mill for 10 minutes, and the -200 mesh content reached 90.12%. A high gradient magnetic separator was used for sorting and impurity removal. At a magnetic field intensity of 0.3 T, a vertical ring speed of 6.0 r / min, a stroke of 12 mm, and a stroke of 100 r / min, the obtained high-quality titanium concentrate contained 47.08% TiO2, 1.02% SiO2, 0.17% CaO, and 0.45% MgO. The titanium recovery rate was 80.12%, and the yield of high-quality titanium concentrate was 75.56%.

[0024] S3 The high-quality titanium concentrate obtained in S2 is smelted in an electric furnace at a smelting temperature of 1750°C for 1 hour to obtain high-titanium slag with TiO2: 87.15%, TFe: 4.95%, SiO2: 2.11%, CaO: 0.33%, MgO: 0.92%, which can meet the requirements of boiling chlorination furnace charge.

[0025] After selecting ilmenite concentrate with a magnesium content of less than 0.5% by mass in the ilmenite mineral phase as the raw material for subsequent selection, the above steps S2 and S3 are repeated to continuously produce more than 100 tons of high-titanium slag that meets the requirements of boiling chlorination furnace charge.

[0026] Comparative Example 1 The other conditions are the same as those in Example 1, except that the raw titanium concentrate is smelted in an electric furnace at a smelting temperature of 1700°C for 2 hours to obtain high-titanium slag with TiO2: 76.85%, TFe: 5.23%, SiO2: 6.52%, CaO: 2.64%, and MgO: 2.89%, which cannot meet the requirements of boiling chlorination furnace charge.

[0027] Comparative Example 2 Other conditions are the same as those in Example 1, except that: The raw ilmenite concentrate was ground by ball mill for 10 minutes, separated and removed by flotation, 500 g / t of sodium oleate as collector, 600 g / t of water glass as inhibitor, 300 g / t of hydrochloric acid as adjuster were selected, and the obtained titanium concentrate contained 46.12% TiO2, 1.56% SiO2, 0.35% CaO and 0.89% MgO. The recovery rate of titanium was 70.23%, and the yield of high-quality titanium concentrate was 75.63%.

[0028] S2 smelted the high-quality titanium concentrate obtained by S1 in an electric furnace at a smelting temperature of 1700°C for 2 hours, and obtained high-titanium slag with TiO2: 82.23%, TFe: 4.96%, SiO2: 3.11%, CaO: 0.72%, and MgO: 1.66%, which could not meet the requirements of boiling chlorination furnace charge.

[0029] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. For those skilled in the art, improvements and changes obtained without departing from the technical concept of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A process for preparing boiling chlorination furnace charge by ilmenite concentrate selection-electric furnace smelting, characterized in that: The following steps are involved: S1 Analyze the element distribution state of ilmenite iron ore in different regions, and select ilmenite concentrate with magnesium content less than 0.5% by mass in the ilmenite mineral phase as the selected raw material; S2 grinding the ilmenite concentrate selected in S1 and then beneficiating and removing impurities to obtain high-quality titanium concentrate; the mass percentage of MgO in the high-quality titanium concentrate is ≤0.5%; S3 The high-quality ilmenite concentrate obtained in S2 is smelted in an electric furnace to obtain high-titanium slag that meets the requirements of boiling chlorination furnace charge.

2. The process for preparing boiling chlorination furnace charge by ilmenite concentrate concentration-electric furnace smelting according to claim 1, characterized in that: The analysis method of the element distribution state of ilmenite includes one or more of scanning electron microscope-energy spectrum analysis, electron probe and the like.

3. The process for preparing boiling chlorination furnace charge by titanium concentrate concentration-electric furnace smelting according to claim 1 is characterized in that: Ilmenite with a magnesium content of less than 0.5% in the ilmenite mineral phase, including ilmenite concentrates with an average mass percentage of magnesium in non-gangue components of less than 0.5%.

4. The process for preparing boiling chlorination furnace charge by ilmenite concentrate concentration-electric furnace smelting according to claim 1, characterized in that: The ilmenite grinding method includes one or more of ball milling, high pressure roller milling, damp milling, vertical milling and the like; the ilmenite concentration and impurity removal method includes one or more of magnetic separation, flotation, gravity separation and the like.

5. The process for preparing boiling chlorination furnace charge by ilmenite concentrate concentration-electric furnace smelting according to claim 1, characterized in that: The beneficiation and impurity removal process comprises: grinding the ilmenite concentrate selected by S1 by a ball mill for 8-15 minutes, preferably for 10 minutes, separating and removing impurities by flotation, selecting a collector of sodium oleate of 1200-1700 g / t, preferably 1400-1600 g / t, a depressant of water glass of 700-900 g / t, preferably 750-850 g / t, and a regulator of hydrochloric acid of 800-1200 g / t, preferably 900-1100 g / t, and more preferably 1000 g / t, to obtain high-quality titanium concentrate.

6. The process for preparing boiling chlorination furnace charge by ilmenite concentrate concentration-electric furnace smelting according to claim 1, characterized in that: The beneficiation and impurity removal comprises: grinding the ilmenite concentrate selected by S1 with a ball mill for 8-15 minutes, preferably for 10 minutes, and separating and removing impurities with a high gradient magnetic separator, at a magnetic field strength of 0.4-0.6 T, a vertical ring speed of 5.5-6.5 r / min, preferably 6.0 r / min, a stroke of 11-13 mm, preferably 12 mm, and a stroke of 90-110 r / min, 100 r / min, to obtain high-quality titanium concentrate.

7. The process for preparing boiling chlorination furnace charge by ilmenite concentrate concentration-electric furnace smelting according to claim 1, characterized in that: In the high-quality titanium concentrate obtained by S2, calculated by mass percentage, TiO2≥46%, SiO2≤1.4%, MgO≤0.5%, and CaO≤0.18%.

8. The process for preparing boiling chlorination furnace charge by ilmenite concentrate concentration-electric furnace smelting according to claim 1, characterized in that: In S3, the temperature of the electric furnace smelting is 1600~1750℃, and the smelting time is 1~3 hours.

9. The process for preparing boiling chlorination furnace charge by titanium concentrate concentration-electric furnace smelting according to claim 1, characterized in that: In the high-titanium slag obtained after smelting in an electric furnace, TiO2≥85%, SiO2≤2.5%, MgO≤1.0%, and CaO≤0.35%, calculated by mass percentage.

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