Experimental research and development of an ilmenite ore beneficiation in Hebei Province

The ilmenite ore is located in Chengde City, Hebei Province. It is a high-phosphorus, low-sulfur, lean ore with a TiO2 grade of 7.31%. In view of the characteristics of this ore, the author conducted a study on the combined shaking table gravity separation and flotation process of this ore. Using this beneficiation process, titanium concentrate with a TiO2 grade of 45.53% and a recovery rate of 68.78% can be obtained. Provide technical guarantee for the development and utilization of this resource.
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1. Ore properties
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(1) Primary chemical composition analysis and phase analysis
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The main chemical  etching composition analysis results of raw ore are shown in Table 1, and the titanium phase analysis results are shown in
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(2) Mineral composition
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There are few types of mineral deposits in ores, and elements such as titanium, iron, and phosphorus in ores mainly exist in independent mineral deposits. The independent mineral deposits of titanium are mainly ilmenite and a very small amount of rutile; the iron ore deposits are mainly magnetite, hematite, and trace amounts of vanadium-containing magnetite, limonite, and pyrite; phosphorus The main mineral deposits are fluorapatite; the main gangue deposits are pyroxene, hornblende, a small amount of olivine, chlorite, plagioclase, serpentine and trace amounts of biotite, sphene, etc.
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(3) Distribution characteristics of primary metal mineral deposits in ores
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1. Ilmenite
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Ilmenite is the main titanium-containing mineral deposit in the ore and is also the main recovery target. Ilmenite is mostly embedded in gangue deposits in irregular granular shapes. It is common to fill in the gaps between gangue grains to form a sponge crystal iron structure; a small number of fine-grained and micro-fine-grained ilmenite are scattered in gangue deposits; titanium iron The ore is often closely symbiotic with aggregates of fine-grained and fine-grained magnetite and hematite, forming part of the rim structure, including structural and complex symbiotic relationships. Aggregations of magnetite and hematite can also be seen. The bodies are present in ilmenite in the form of inclusions; sometimes the aggregates of magnetite and hematite are filled along the cracks and gaps of the ilmenite grains; through scanning electron microscopy, the relationship between ilmenite and magnetite and hematite can be seen. A network structure composed of aggregates; common round granular apatite and ilmenite are in a simple symbiotic relationship. The particle size of ilmenite is generally 0.043~0.417mm.
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2. Magnetite
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The main iron ore deposit in the ore, altered hematite often forms fine rhombus-shaped, network-shaped and irregular aggregates of magnetite and hematite along the gaps of magnetite grains. The aggregates are mostly in the form of fine-grained and micro-grained irregular granular shapes along the edges of the ilmenite, including structures. Common fine-grained and micro-grained inclusions are scattered in the gangue deposits. Magnetite embedding can also be seen. In the chain-like structure in the gangue, sometimes fine network veins of magnetite can be seen embedded in the gangue mineral deposits, and occasionally the euhedral crystal structure of magnetite can be seen. It is common for magnetite to form a rim structure along the edges of apatite grains. Generally, the edge contribution of magnetite with this structure is 5 μm. The particle size of the symbiotic aggregates of magnetite and hematite in the ore is relatively fine, and it is difficult to dissociate from the gangue. The particle size of magnetite and hematite aggregates is generally 0.015~0.074mm.
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3. Hematite
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Hematite is a common oxide of iron in ores. It often forms fine needle-shaped, rhombus-shaped lattice-shaped, parallel-shaped, etc. along the gaps of magnetite grains. The embedding of hematite and magnetite is closely related. , mostly forming complex aggregates of hematite and magnetite. The particle size of hematite is generally 0.001~0.05mm.
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4. False horn hematite
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The amount of false hematite in the ore is small. The false hematite is formed by the oxidative alteration of magnetite. It is mainly embedded in the cracks and edges of magnetite, often with a border structure, and is embedded in an aggregate form. Distributed in gangue. The particle size range of imaginary hematite is 0.002~0.15mm.
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5. Magnetite containing vanadium and titanium
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Vanadium- and titanium parts  magnetite is mainly embedded in the gangue mineral deposits in the form of fine-grained, fine-grained round granules and irregular granules, sometimes symbiotic with aggregates of magnetite and hematite; occasionally, titanium-containing magnetite can be seen. Iron ore is produced in the form of leaf-shaped, finely granular inclusions in ilmenite, and scanning electron microscopy energy spectrum analysis results show that vanadium is unevenly distributed in them. The particle size of vanadium-titanium-containing magnetite is generally 0.002~0.02mm.
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6. Pyrite, limonite
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Pyrite is the main mineral deposit of sulfur in this ore. It is mostly embedded in ilmenite, magnetite and gangue as extremely fine round granular inclusions. It has a relatively close symbiotic relationship with magnetite and its content is very small. , only 0.03%. The particle size of pyrite is mostly less than 5 μm. Limonite is often embedded in the gangue in irregular shapes and veins. It is an optional mineral deposit in the ore. The particle size is generally 50 μm.
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2. Discussion on mineral processing technology
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(1) Shaking table re-selection experiment
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Under the conditions of different grinding fineness, a shaking table gravity separation and discarding experiment was carried out. The experimental results are shown in Figure 1. It can be seen from the experimental results that as the grinding fineness increases, the TiO2 grade and recovery rate of the shaker concentrate increase. However, when the grinding fineness -74 μm accounts for 65% and then increases, the TiO2 recovery rate of the shaker concentrate increases. Decrease, so it is determined that the grinding fineness -74μm accounts for 65%.

(2) Flotation experiment
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The raw ore is gravity separated under the condition that the grinding fineness is -74μm accounting for 65% to produce shaker concentrate, and then flotation experiments are conducted on the shaker concentrate to improve the grade of Custom titanium parts concentrate TiO2.
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1. Experiment on adjusting the dosage of agent
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​BK515 was selected as the regulator. The experimental process is shown in Figure 2, and the experimental results are shown in Figure 3. It can be seen from the experimental results that as the amount of BK515 increases, the recovery of TiO2 in the titanium concentrate increases. When the amount of BK515 is increased to 700g/t and then added, the recovery rate of TiO2 in the titanium concentrate decreases, while the TiO2 grade does not increase much. Therefore, it is concluded that the dosage of BK515 is 700g/t.

2. Sulfuric acid dosage experiment
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Ilmenite has better flotation results under acidic conditions, so an experiment on the amount of sulfuric acid used in the flotation operation was carried out. The sulfuric acid dosage experiment was carried out under the condition that the grinding fineness of -74 μm accounted for 70% of the shaker concentrate. The chemical conditions were BK515 700g/t, BK465 600g/t, and pine alcohol oil 50g/t. The experimental results are shown in Figure 4. It can be seen from the sulfuric acid dosage experiment that when the sulfuric acid dosage is 1000g/t, the TiO2 grade and recovery rate of the concentrate are higher; when the sulfuric acid dosage is added again, the TiO2 recovery rate of the ilmenite concentrate decreases, so it is concluded that the sulfuric acid dosage is 1000g/t .

3. Collector dosage experiment
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​BK465 is selected as the collector. The BK465 dosage experiment was carried out on a shaking table concentrate with a grinding fineness of -74 μm accounting for 70%. The chemical conditions were BK515 700g/t, sulfuric acid 1000g/t, and pine alcohol oil 50g/t. The experimental results are shown in Figure 5. It can be seen from the collector dosage experiment that as the collector dosage increases, the TiO2 recovery rate of ilmenite increases, but when the dosage reaches 600g/t and is added again, the TiO2R grade drops significantly, so it is determined that the collector dosage is 600g /t.

4. Grinding fineness experiment
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When conducting the grinding fineness experiment on shaker concentrate, the chemical conditions were BK515 700g/t, sulfuric acid 1000g/t, BK465 600g/t, and pine alcohol oil 50g/t. The experimental results are shown in Figure 6. It can be seen from the results of the grinding fineness experiment that as the grinding fineness increases, the TiO2 grade of the titanium concentrate basically remains unchanged. When the grinding fineness -74 μm accounts for 70% and then increases, the recovery rate of TiO2 of the titanium concentrate Decrease, so it is determined that the grinding fineness -74μm accounts for 70%.

5. Experiment on the dosage of sulfuric acid for coarse concentrate concentration
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Because the dosage of sulfuric acid has a great impact on the beneficiation of flotation titanium machining rough concentrate, an experiment on the dosage of sulfuric acid for flotation titanium rough concentrate was carried out. See the experiment on the dosage of sulfuric acid for coarse concentrate concentration, and see the experimental results. It can be seen from the experimental results of the dosage of refined sulfuric acid that as the dosage of sulfuric acid increases, the TiO2 grade and recovery of ilmenite concentrate increase. When the dosage of sulfuric acid increases to 150g/t, the recovery rate of TiO2 does not increase significantly, so it is concluded that the coarse concentrate is fine. The acid charging dosage is 150g/t.
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​ 6. Flotation open circuit experiment
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Based on the flotation condition experiment, the flotation open-circuit experiment was carried out on the shaking table gravity separation titanium investment casting concentrate under the condition that the regrinding fineness was -74μm accounting for 70%. The experimental flow is shown in Figure 9, and the experimental results are shown in
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7. Flotation closed-circuit experiment
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Based on the open-circuit flotation experiment, a closed-circuit flotation experiment was conducted on the shaker gravity separation concentrate. The experimental flow is shown in Figure 10, and the experimental results are shown in Table 4. During the closed-circuit experiment, in order to keep the pH of each section of operation constant, the amount of flowing acid was reduced.

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8. Shaking table gravity separation-flotation combined process flow
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The combined process flow of shaking table gravity separation and flotation is shown in Figure 11, and the process objectives are shown in Table 5.
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3. Conclusion
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(1) The ore contains TiO27.31%, P1.20%, and S0.018%, and is a high-phosphorus and low-sulfur poor ilmenite.
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(2) The ore was processed using the combined process of shaking table gravity separation and shaking table concentrate flotation, and the technical targets of titanium concentrate TiO2 grade of 45.53% and TiO2 recovery rate of 68.78% were achieved.
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(3) Provide technical guarantee for the development and utilization of this resource.