A flotation method for improving the recovery of coarse-grained ilmenite

Abstract

This invention relates to a flotation method for improving the recovery rate of coarse-grained ilmenite, belonging to the field of mineral flotation separation and comprehensive utilization technology. The invention involves preparing a slurry from coarse-grained ilmenite for flotation desulfurization. Before flotation, strong stirring is used to condition the slurry, followed by the addition of flotation reagents for a single stage of flotation. After coarse and fine classification, a second stage of flotation is performed to finally obtain ilmenite concentrate. This process, through strong stirring of the ilmenite slurry, effectively weakens the heterogeneous agglomeration between ilmenite and gangue mineral particles, enhances the interaction between flotation reagents and the mineral surface, achieving a high-grade and high-recovery enrichment effect. Through screening and classification, qualified coarse-grained ilmenite can be pre-recovered, reducing losses in subsequent cleaning operations and contributing to an improved overall recovery rate of ilmenite. Pre-recovering qualified ilmenite through classification significantly reduces the amount of ore entering subsequent cleaning operations, reducing the amount of beneficiation equipment and flotation reagents used, thus lowering costs.

Description

Technical Field

[0001] This invention belongs to the field of mineral flotation separation and comprehensive utilization technology, specifically relating to a flotation method for improving the recovery rate of coarse-grained ilmenite. Background Technology

[0002] my country possesses relatively abundant titanium resources. The Panzhihua-Xichang region in Sichuan Province is my country's main primary ilmenite deposit, containing over 93% of the country's titanium resources. In the Panzhihua-Xichang region, titanium resources are hosted in basic to ultrabasic rock masses, making them difficult to develop and utilize. Currently, the main process involves separating the ilmenite feedstock into coarse and fine particles using a "grading + strong magnetic separation + flotation" method. However, the recovery rate of ilmenite resources remains low, with flotation operations achieving a recovery rate of around 75%. Improving the recovery rate of ilmenite is a key technical challenge.

[0003] For flotation processes, the particle size of the feed material has a significant impact. In the flotation of coarse-grained ilmenite, due to its high specific gravity and coarse size, ilmenite particles cannot form effective mineralization bubbles, easily leading to flotation cell compression, which is a major reason for the low recovery rate of coarse-grained ilmenite. Therefore, high-concentration separation is often used in coarse-grained ilmenite flotation, increasing the pulp concentration to reduce the relative specific gravity of ilmenite and increasing the amount of reagent used to improve the adhesion between coarse-grained ilmenite and bubbles. However, high pulp concentration and high reagent dosage can easily cause heterogeneous agglomeration between ilmenite and gangue particles, which also greatly affects the flotation separation of ilmenite. Ultimately, this results in a long ilmenite flotation process, high reagent costs, and less than ideal separation indicators, failing to achieve the goal of efficient utilization of titanium resources. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a flotation method for improving the recovery rate of coarse-grained ilmenite. This method can significantly improve the recovery rate of titanium concentrate and reduce the cost of ilmenite beneficiation.

[0005] To achieve the above objectives, the present invention adopts the following technical solution:

[0006] A flotation method for improving the recovery rate of coarse-grained ilmenite includes the following process steps:

[0007] Step 1: Prepare a slurry from coarse-grained ilmenite feedstock with a slurry concentration of 30-40%. Add collectors and frothers to carry out ilmenite flotation desulfurization. The desulfurization process is a single roughing process. The roughing concentrate is sulfur concentrate, and the flotation tailings are ilmenite flotation feedstock.

[0008] Step 2: The ilmenite flotation raw material obtained in Step 1 is subjected to strong stirring and slurry preparation, and flotation reagents are gradually added. The flotation reagents include sodium carbonate as a pH adjuster, lead nitrate as an ilmenite activator, and benzoic acid as an ilmenite collector. The ilmenite flotation slurry is prepared by strong stirring and slurry preparation.

[0009] Step 3: Perform a first-stage flotation on the ilmenite slurry described in Step 2. The flotation process includes a roughing operation and a scavenging operation. The roughing concentrate is the first-stage flotation concentrate of ilmenite, and the scavenging tailings are the flotation tailings. The scavenging concentrate is returned to the ilmenite roughing operation.

[0010] Step 4: The ilmenite primary flotation concentrate described in Step 3 is further classified into coarse and fine particles. The coarse particle product is titanium concentrate I, and the fine particle product is the ilmenite secondary flotation feedstock.

[0011] Step 5: Perform two-stage flotation on the ilmenite two-stage flotation raw material described in Step 4. The two-stage flotation includes a roughing operation and a cleaning operation to obtain titanium concentrate II. The tailings from the two-stage roughing operation are returned to the first-stage flotation roughing operation as middlings. The tailings from the first-stage cleaning operation are returned to the second-stage flotation roughing operation as middlings. Concentrate I and concentrate II are combined to form the final ilmenite concentrate.

[0012] The coarse-grained ilmenite flotation feed material mentioned in step 1 has a particle size of -0.25mm content ≥95%, a particle size of -0.075mm content 20-30%, and a total content of ilmenite monomers and rich intergrowths in the coarse-grained ilmenite flotation feed material greater than 90%, and the volume of ilmenite particles in the rich intergrowths is greater than 3 / 4.

[0013] The collector mentioned in step 1 is butyl xanthate, and the foaming agent is No. 2 oil.

[0014] The strong stirring and slurry conditioning described in step 2 is carried out in a laboratory-type flotation machine. During slurry conditioning, the stirring speed is controlled at 2600-3000 r / min. Strong stirring weakens the heterogeneous agglomeration between ilmenite and gangue mineral particles.

[0015] The slurry conditioning time for adding flotation reagents in step 2 is as follows: add sodium carbonate for 5 minutes, lead nitrate for 5 minutes, and benzoic acid for 10-20 minutes in sequence to ensure that the interaction between minerals and flotation reagents is enhanced under the condition that the mineral particles are fully dispersed.

[0016] The pH value of the ilmenite flotation slurry mentioned in step 3 is 7.5-8.0; the scavenging operation involves adding sodium carbonate as a pH adjuster and conditioning the slurry for 2-4 minutes, lead nitrate as an activator and conditioning the slurry for 2-4 minutes, and benzoic acid as a collector and conditioning the slurry for 4-6 minutes.

[0017] In step 4, the coarse and fine classification of the ilmenite primary flotation concentrate is carried out by hydraulic classification, with a preferred sieve size of 0.075 mm, to pre-recover qualified coarse ilmenite.

[0018] The pH value of the second-stage flotation pulp of the ilmenite second-stage flotation raw material mentioned in step 5 is 7.5-8.0, and the ore-mineralization sequence of the flotation is returned.

[0019] In step 5, the two-stage flotation roughing operation involves adding 300-400 g / t of water glass as a dispersant and adjusting the slurry for 5 minutes to ensure sufficient dispersion of the fine-grained ilmenite slurry system. No water glass is required for the two-stage flotation cleaning operation.

[0020] In steps 3 and 5, flotation is performed by skimming bubbles. The skimming is done using a flotation machine with a rotation speed of 1992 r / min.

[0021] The flotation method for improving the recovery rate of coarse-grained ilmenite proposed in this invention has the following advantages compared with the prior art:

[0022] (1) The present invention employs strong stirring and slurry conditioning before flotation of ilmenite, which can weaken the heterogeneous agglomeration of ilmenite and gangue mineral particles on the one hand, and enhance the interaction between flotation reagents and mineral surfaces on the other hand, significantly enhancing the enrichment effect of ilmenite flotation and improving separation index.

[0023] (2) Screening and grading operations are set up before the beneficiation of ilmenite, which can ensure that most of the coarse-grained ilmenite in the first stage of flotation concentrate does not enter the subsequent second stage of flotation, which helps to "recover the coarse-grained ilmenite as soon as possible" and thus improves the overall recovery rate.

[0024] (3) The present invention adopts a grading operation to pre-recover qualified ilmenite, which will greatly reduce the amount of ore entering the subsequent beneficiation operation, reduce the amount of beneficiation equipment and flotation reagents used, and reduce costs. Attached Figure Description

[0025] Figure 1 This is a flow chart of a flotation method for improving the recovery rate of coarse-grained ilmenite according to an embodiment of the present invention;

[0026] Figure 2 The flowchart for a conventional flotation process consisting of one roughing, one scavenging, and two cleaning stages is shown for comparison. Detailed Implementation

[0027] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0028] Example 1

[0029] This embodiment provides a flotation method for improving the recovery rate of coarse-grained ilmenite, the process of which is as follows: Figure 1 As shown; the ilmenite feedstock was taken from a high-magnetic concentrate from a beneficiation plant in the Panxi region. Elemental chemical analysis showed a TiO2 grade of 16.95%, and particle size analysis revealed that -0.25mm particles accounted for 95.26%, -0.075mm particles accounted for 22.10%, and the total content of monomers and rich intergrowths was 90.28%. The specific steps included in the example are as follows:

[0030] Step 1: Prepare a slurry with a mass concentration of 40% by preparing ilmenite feedstock, add 300g / t of butyl xanthate collector (based on the amount of ilmenite feedstock), stir for 5 minutes, add 60g / t of No. 2 oil frother, stir for 2 minutes. The desulfurization process is a single roughing process, the roughing concentrate is sulfur concentrate, and the flotation tailings are ilmenite flotation feedstock.

[0031] Step 2: The coarse-grained ilmenite flotation raw material obtained in Step 1 is subjected to strong stirring and slurry preparation to obtain ilmenite flotation slurry. This is carried out in a laboratory-type flotation machine, with the stirring speed controlled at 2600 r / min. During the strong stirring and slurry preparation process, flotation reagents are added, including 600 g / t of sodium carbonate as a pH adjuster, with the slurry pH value set to 8.0, and slurry preparation for 5 min. Then, 400 g / t of lead nitrate as an ilmenite activator is added, and slurry preparation for 5 min is completed. Finally, 1600 g / t of benzoic acid as an ilmenite collector is added, and slurry preparation for 20 min is completed.

[0032] Step 3: Perform a primary flotation on the ilmenite slurry obtained in Step 2. The primary flotation of ilmenite includes one roughing operation and one scavenging operation. For the ilmenite scavenging operation, add 200g / t of sodium carbonate (pH adjuster) to the flotation machine and condition the slurry for 3 minutes, 150g / t of lead nitrate (activator) and condition the slurry for 3 minutes, and 600g / t of benzoyl hydroxamic acid (collector) and condition the slurry for 5 minutes. During flotation, skimming is performed using a flotation machine at a speed of 1992 r / min. The roughing concentrate is the primary flotation concentrate of ilmenite, and the scavenging tailings are the flotation tailings. The scavenging concentrate is returned to the ilmenite roughing operation.

[0033] Step 4: The ilmenite primary flotation concentrate obtained in Step 3 is subjected to coarse and fine classification. The sieve size used for classification is 0.075 mm. The coarse part is used as qualified titanium concentrate I, and the fine part is used as raw material for the second stage of ilmenite flotation.

[0034] Step 5: Perform two-stage flotation on the ilmenite raw material obtained in Step 4. The two-stage flotation includes one roughing and one cleaning operation. The pH value of the ilmenite flotation pulp is 8.0. The ore concentrate is returned sequentially during flotation. Foam removal is performed during flotation using a flotation machine at a speed of 1992 r / min. For the roughing operation, 300 g / t of water glass is added as a dispersant, and the pulp conditioning time is 3 min. No water glass is added for the cleaning operation. The concentrate from the two-stage flotation is designated as qualified titanium concentrate II. Concentrate I and concentrate II are combined to form the final ilmenite concentrate.

[0035] The final ilmenite concentrate had a TiO2 grade of 47.23% and a recovery rate of 82.51%.

[0036] Comparative Example 1

[0037] The comparative flotation process flow chart is as follows: Figure 2 As shown, the raw material and flotation reagent system for ilmenite are the same as in Example 1. The difference from Example 1 is that step 2, strong stirring and pulp conditioning, is not performed in this comparative example, and coarse and fine classification is not performed before step 4, fine selection.

[0038] The final ilmenite concentrate obtained in this comparative example has a TiO2 grade of 46.42% and a recovery rate of 74.87%.

[0039] The sorting results of Example 1 and Comparative Example 1 are shown in Table 1. The TiO2 grade of the ilmenite concentrate obtained in Example 1 was 47.23% and the recovery rate was 82.51%. Compared with Comparative Example 1, the TiO2 grade increased by 0.81 percentage points and the recovery rate increased by 7.64 percentage points.

[0040] Table 1 shows the ilmenite sorting results of Example 1 and Comparative Example 1.

[0041]

[0042] Table 1

[0043] Example 2

[0044] This embodiment provides a flotation method to improve the recovery rate of coarse-grained ilmenite. The ilmenite feedstock is taken from a strong magnetic concentrate from a beneficiation plant in the Panxi region. Elemental chemical analysis shows a TiO2 grade of 18.40%, and particle size analysis shows that the proportion of -0.25mm particles in the feedstock is 96.24%, the proportion of -0.075mm particles is 25.35%, and the total content of monomers and rich intergrowths is 92.67%. The embodiment specifically includes the following steps:

[0045] Step 1: Prepare the ilmenite feedstock into a slurry with a mass concentration of 35%, add 300g / t of butyl xanthate collector, stir for 5 minutes, add 60g / t of No. 2 oil frother, stir for 2 minutes. The desulfurization process is a single roughing process, the roughing concentrate is sulfur concentrate, and the flotation tailings are ilmenite flotation feedstock.

[0046] Step 2: The coarse-grained ilmenite flotation raw material obtained in Step 1 is subjected to strong stirring and slurry preparation to obtain ilmenite flotation slurry. The stirring speed is controlled at 2800 r / min. During the strong stirring and slurry preparation process, flotation reagents are added, including 600 g / t of sodium carbonate as a pH adjuster, the pH value of the slurry is 8.0, and the slurry is prepared for 5 min. Then, 400 g / t of lead nitrate as an ilmenite activator is added, and the slurry is prepared for 5 min. Finally, 1600 g / t of benzoic acid as an ilmenite collector is added, and the slurry is prepared for 20 min.

[0047] Step 3: Perform a primary flotation on the ilmenite slurry obtained in Step 2. The primary flotation of ilmenite includes one roughing operation and one scavenging operation. For the ilmenite scavenging operation, add 200g / t of sodium carbonate (pH adjuster) to the flotation machine and condition the slurry for 3 minutes, 150g / t of lead nitrate (activator) and condition the slurry for 3 minutes, and 600g / t of benzoyl hydroxamic acid (collector) and condition the slurry for 5 minutes. During flotation, skimming is performed using a flotation machine at a speed of 1992 r / min. The roughing concentrate is the primary flotation concentrate of ilmenite, and the scavenging tailings are the flotation tailings. The scavenging concentrate is returned to the ilmenite roughing operation.

[0048] Step 4: The ilmenite primary flotation concentrate obtained in Step 3 is subjected to coarse and fine classification. The sieve size used for classification is 0.075 mm. The coarse part is used as qualified titanium concentrate I, and the fine part is subjected to ilmenite secondary flotation.

[0049] Step 5: The fine-grained ilmenite obtained in Step 4 is subjected to two-stage flotation, which includes a roughing operation and a cleaning operation. The pH value of the ilmenite flotation pulp is 8.0. The ore is returned sequentially during flotation. Foam removal is performed during flotation using a flotation machine at a speed of 1992 r / min. For the roughing operation, 300 g / t of water glass is added as a dispersant, and the pulp conditioning time is 3 min. No water glass is added for the cleaning operation. The concentrate from the second-stage flotation is designated as qualified titanium concentrate II. Concentrate I and concentrate II are combined to form the final ilmenite concentrate.

[0050] The final ilmenite concentrate had a TiO2 grade of 47.56% and a recovery rate of 83.87%.

[0051] Comparative Example 2

[0052] The raw material and flotation reagent system for this comparative example of ilmenite are the same as those in Example 2, except that the strong stirring and slurry conditioning in step 2 are not performed in Comparative Example 2, and no coarse and fine classification is performed before the fine selection in step 4.

[0053] The final ilmenite concentrate obtained in this comparative example has a TiO2 grade of 46.89% and a recovery rate of 76.78%.

[0054] The sorting results of Example 2 and Comparative Example 2 are shown in Table 2. The TiO2 grade of the ilmenite concentrate obtained in Example 2 was 47.56% and the recovery rate was 83.87%. Compared with the comparative example, the TiO2 grade increased by 0.67 percentage points and the recovery rate increased by 7.09 percentage points.

[0055] Table 2 shows the ilmenite separation results of Example 2 and Comparative Example 2.

[0056]

[0057]

[0058] Table 2

[0059] Example 3

[0060] This embodiment provides a flotation method to improve the recovery rate of coarse-grained ilmenite. The ilmenite feedstock is taken from a secondary strong magnetic concentrate from a beneficiation plant in the Panxi region. Elemental chemical analysis shows a TiO2 grade of 20.87%, and particle size analysis shows that the proportion of -0.25mm particles in the feedstock is 97.84%, the proportion of -0.075mm particles is 29.86%, and the total content of monomers and rich intergrowths is 94.74%. The embodiment specifically includes the following steps:

[0061] Step 1: Prepare the ilmenite feedstock into a slurry with a mass concentration of 30%, add 300g / t of butyl xanthate collector, stir for 5 minutes, add 60g / t of No. 2 oil frother, stir for 2 minutes. The desulfurization process is a single roughing process, the roughing concentrate is sulfur concentrate, and the flotation tailings are ilmenite flotation feedstock.

[0062] Step 2: The coarse-grained ilmenite flotation raw material obtained in Step 1 is subjected to strong stirring and slurry preparation to obtain ilmenite flotation slurry. The stirring speed is controlled at 3000 r / min. During the strong stirring and slurry preparation process, flotation reagents are added, including 500 g / t of sodium carbonate as a pH adjuster, the pH value of the slurry is 7.5, and the slurry is prepared for 5 min. Then, 450 g / t of lead nitrate as an ilmenite activator is added, and the slurry is prepared for 5 min. Finally, 1800 g / t of benzoic acid as an ilmenite collector is added, and the slurry is prepared for 10 min.

[0063] Step 3: Perform a primary flotation on the strongly stirred ilmenite flotation pulp obtained in Step 2. The primary flotation of ilmenite includes one roughing operation and one scavenging operation. For the ilmenite scavenging operation, add 150 g / t of sodium carbonate (pH adjuster) to the flotation machine and condition the pulp for 3 min, 150 g / t of lead nitrate (activator) and condition the pulp for 3 min, and 600 g / t of benzoyl hydroxamic acid (collector) and condition the pulp for 5 min. During flotation, skimming is performed using a flotation machine at a speed of 1992 r / min. The roughing concentrate is the primary flotation concentrate of ilmenite, and the scavenging tailings are the flotation tailings. The scavenging concentrate is returned to the ilmenite roughing operation.

[0064] Step 4: The ilmenite primary flotation concentrate obtained in Step 3 is subjected to coarse and fine classification. The sieve size used for classification is 0.075 mm. The coarse part is used as qualified titanium concentrate I, and the fine part is subjected to ilmenite secondary flotation.

[0065] Step 5: The fine-grained ilmenite obtained in Step 4 is subjected to two-stage flotation, which includes a roughing operation and a cleaning operation. The pH value of the ilmenite flotation pulp is 7.5, and the concentrate is returned sequentially. During flotation, frothing is performed using a flotation machine at a speed of 1992 r / min. In the roughing operation of the second-stage flotation, 400 g / t of water glass is added as a dispersant, and the pulp conditioning time is 3 min. No water glass is added in the cleaning operation. The concentrate from the second-stage flotation is designated as qualified titanium concentrate II. Concentrate I and concentrate II are combined to form the final ilmenite concentrate.

[0066] The final ilmenite concentrate had a TiO2 grade of 47.65% and a recovery rate of 84.23%.

[0067] Comparative Example 3

[0068] In this comparative example, the raw material and flotation reagent system for ilmenite are the same as in Example 3. The difference is that this comparative example does not perform strong stirring and pulp conditioning in step 2, and does not perform coarse and fine classification before fine selection in step 4.

[0069] The final ilmenite concentrate had a TiO2 grade of 47.29% and a recovery rate of 78.72%.

[0070] The sorting results of Example 3 and Comparative Example 3 are shown in Table 3. The TiO2 grade of the ilmenite concentrate obtained in Example 3 was 47.65% and the recovery rate was 84.23%. Compared with the comparative example, the TiO2 grade increased by 0.36 percentage points and the recovery rate increased by 5.51 percentage points.

[0071] Table 3 shows the ilmenite separation results of Example 3 and Comparative Example 3.

[0072]

[0073] Table 3

[0074] Example 4

[0075] This embodiment provides a flotation method to improve the recovery rate of coarse-grained ilmenite. The ilmenite feedstock is taken from a secondary strong magnetic concentrate from a beneficiation plant in the Panxi region. Elemental chemical analysis shows a TiO2 grade of 17.68%, and particle size analysis shows that the proportion of -0.25mm particles in the feedstock is 96.38%, the proportion of -0.075mm particles is 25.94%, and the total content of monomers and rich intergrowths is 91.82%. The embodiment specifically includes the following steps:

[0076] Step 1: Prepare the ilmenite feedstock into a slurry with a mass concentration of 35%, add 300g / t of butyl xanthate collector, stir for 5 minutes, add 60g / t of No. 2 oil frother, stir for 2 minutes. The desulfurization process is a single roughing process, the roughing concentrate is sulfur concentrate, and the flotation tailings are ilmenite flotation feedstock.

[0077] Step 2: The coarse-grained ilmenite flotation raw material obtained in Step 1 is subjected to strong stirring and slurry preparation to obtain ilmenite flotation slurry. The stirring speed is controlled at 3000 r / min. During the strong stirring and slurry preparation process, flotation reagents are added, including 500 g / t of sodium carbonate as a pH adjuster, with the slurry pH value at 7.5, and slurry preparation for 5 min. Then, 450 g / t of lead nitrate as an ilmenite activator is added, and slurry preparation for 5 min is completed. Finally, 1700 g / t of benzoic acid as an ilmenite collector is added, and slurry preparation for 15 min is completed.

[0078] Step 3: Perform a primary flotation on the ilmenite slurry obtained in Step 2. The primary flotation of ilmenite includes one roughing operation and one scavenging operation. For the ilmenite scavenging operation, add 150 g / t of sodium carbonate (pH adjuster) to the flotation machine for 3 minutes, 150 g / t of lead nitrate (activator) for 3 minutes, and 600 g / t of benzoyl hydroxamic acid (collector) for 5 minutes. During flotation, skimming is performed using a flotation machine at a speed of 1992 r / min. The roughing concentrate is the primary flotation concentrate of ilmenite, and the scavenging tailings are the flotation tailings. The scavenging concentrate is returned to the ilmenite roughing operation.

[0079] Step 4: The ilmenite primary flotation concentrate obtained in Step 3 is subjected to coarse and fine classification. The sieve size used for classification is 0.075 mm. The coarse part is used as qualified titanium concentrate I, and the fine part is subjected to ilmenite secondary flotation.

[0080] Step 5: The fine-grained ilmenite obtained in Step 4 is subjected to two-stage flotation, which includes a roughing operation and a cleaning operation. The pH value of the ilmenite flotation pulp is 7.5, and the concentrate is returned sequentially. During flotation, frothing is performed using a flotation machine at a speed of 1992 r / min. In the roughing operation of the second-stage flotation, 400 g / t of water glass is added as a dispersant, and the pulp conditioning time is 3 min. No water glass is added in the cleaning operation. The concentrate from the second-stage flotation is designated as qualified titanium concentrate II. Concentrate I and concentrate II are combined to form the final ilmenite concentrate.

[0081] The final ilmenite concentrate had a TiO2 grade of 47.41% and a recovery rate of 83.56%.

[0082] Example 5

[0083] This embodiment provides a flotation method to improve the recovery rate of coarse-grained ilmenite. The ilmenite feedstock is taken from a secondary strong magnetic concentrate from a beneficiation plant in the Panxi region. Elemental chemical analysis shows a TiO2 grade of 19.36%, and particle size analysis shows that the proportion of -0.25mm particles in the feedstock is 97.05%, the proportion of -0.075mm particles is 28.73%, and the total content of monomers and rich intergrowths is 94.13%. The embodiment specifically includes the following steps:

[0084] Step 1: Prepare the ilmenite feedstock into a slurry with a mass concentration of 35%, add 300g / t of butyl xanthate collector, stir for 5 minutes, add 60g / t of No. 2 oil frother, stir for 2 minutes. The desulfurization process is a single roughing process, the roughing concentrate is sulfur concentrate, and the flotation tailings are ilmenite flotation feedstock.

[0085] Step 2: The coarse-grained ilmenite flotation raw material obtained in Step 1 is subjected to strong stirring and slurry preparation to obtain ilmenite flotation slurry. The stirring speed is controlled at 2800 r / min. During the strong stirring and slurry preparation process, flotation reagents are added, including 600 g / t of sodium carbonate as a pH adjuster, the pH value of the slurry is 8.0, and the slurry is prepared for 5 min. Then, 400 g / t of lead nitrate as an ilmenite activator is added, and the slurry is prepared for 5 min. Finally, 1800 g / t of benzoic acid as an ilmenite collector is added, and the slurry is prepared for 15 min.

[0086] Step 3: Perform a primary flotation on the ilmenite slurry obtained in Step 2. The primary flotation of ilmenite includes one roughing operation and one scavenging operation. For the ilmenite scavenging operation, add 200 g / t of sodium carbonate (pH adjuster) to the flotation machine and condition the slurry for 3 minutes; add 150 g / t of lead nitrate (activator) and condition the slurry for 3 minutes; add 600 g / t of benzoyl hydroxamic acid (collector) and condition the slurry for 5 minutes. During flotation, skimming is performed using a flotation machine at a speed of 1992 r / min. The roughing concentrate is the primary flotation concentrate of ilmenite, and the scavenging tailings are the flotation tailings. The scavenging concentrate is returned to the ilmenite roughing operation.

[0087] Step 4: The ilmenite primary flotation concentrate obtained in Step 3 is subjected to coarse and fine classification. The sieve size used for classification is 0.075 mm. The coarse part is used as qualified titanium concentrate I, and the fine part is subjected to ilmenite secondary flotation.

[0088] Step 5: The fine-grained ilmenite obtained in Step 4 is subjected to two-stage flotation, which includes a roughing operation and a cleaning operation. The pH value of the ilmenite flotation pulp is 8.0, and the concentrate is returned sequentially. During flotation, frothing is performed using a flotation machine at a speed of 1992 r / min. In the roughing operation of the second-stage flotation, 300 g / t of water glass is added as a dispersant, and the pulp conditioning time is 3 min. No water glass is added in the cleaning operation. The concentrate from the second-stage flotation is designated as qualified titanium concentrate II. Concentrate I and concentrate II are combined to form the final ilmenite concentrate.

[0089] The final ilmenite concentrate had a TiO2 grade of 47.60% and a recovery rate of 83.94%.

Claims

1. A flotation method for improving the recovery rate of coarse-grained ilmenite, characterized in that, The process includes the following steps: Step 1: Prepare a slurry from coarse-grained ilmenite feedstock with a slurry concentration of 30-40%. Add collectors and frothers to carry out ilmenite flotation desulfurization. The desulfurization process is a single roughing process. The roughing concentrate is sulfur concentrate, and the flotation tailings are ilmenite flotation feedstock. Step 2: The ilmenite flotation raw material obtained in Step 1 is subjected to strong stirring and slurry preparation, and flotation reagents are gradually added. The flotation reagents include sodium carbonate as a pH adjuster, lead nitrate as an ilmenite activator, and benzoic acid as an ilmenite collector. The ilmenite flotation slurry is prepared by strong stirring and slurry preparation. Step 3: Perform a first-stage flotation on the ilmenite slurry described in Step 2. The flotation process includes a roughing operation and a scavenging operation. The roughing concentrate is the first-stage flotation concentrate of ilmenite, and the scavenging tailings are the flotation tailings. The scavenging concentrate is returned to the ilmenite roughing operation. Step 4: The ilmenite primary flotation concentrate described in Step 3 is further classified into coarse and fine particles. The coarse particle product is titanium concentrate I, and the fine particle product is the ilmenite secondary flotation feedstock. Step 5: Perform two-stage flotation on the ilmenite two-stage flotation raw material described in Step 4. The two-stage flotation includes a roughing operation and a cleaning operation to obtain titanium concentrate II. The tailings from the two-stage roughing operation are returned to the first-stage flotation roughing operation as middlings. The tailings from the first-stage cleaning operation are returned to the second-stage flotation roughing operation as middlings. Concentrate I and concentrate II are combined to form the final ilmenite concentrate.

2. The flotation method for improving the recovery rate of coarse-grained ilmenite according to claim 1, characterized in that, The coarse-grained ilmenite flotation feed material mentioned in step 1 has a particle size of -0.25mm content ≥95%, a particle size of -0.075mm content 20~30%, and a total content of ilmenite monomers and rich intergrowths in the coarse-grained ilmenite flotation feed material greater than 90%, and the volume of ilmenite particles in the rich intergrowths is greater than 3 / 4.

3. The flotation method for improving the recovery rate of coarse-grained ilmenite according to claim 1, characterized in that, The collector mentioned in step 1 is butyl xanthate, and the foaming agent is No. 2 oil.

4. The flotation method for improving the recovery rate of coarse-grained ilmenite according to claim 1, characterized in that, The strong stirring and slurry conditioning described in step 2 is carried out in a laboratory-type flotation machine, and the stirring speed is controlled at 2600~3000 r / min during slurry conditioning.

5. The flotation method for improving the recovery rate of coarse-grained ilmenite according to claim 1, characterized in that, The slurry conditioning time for adding flotation reagents in step 2 is as follows: add sodium carbonate for 5 minutes, lead nitrate for 5 minutes, and benzoic acid for 10-20 minutes in sequence.

6. The flotation method for improving the recovery rate of coarse-grained ilmenite according to claim 1, characterized in that, The pH value of the ilmenite flotation slurry mentioned in step 3 is 7.5~8.0; the scavenging operation involves adding sodium carbonate as a pH adjuster and conditioning the slurry for 2-4 minutes, lead nitrate as an activator and conditioning the slurry for 2-4 minutes, and benzyl hydroxamic acid as a collector and conditioning the slurry for 4-6 minutes.

7. The flotation method for improving the recovery rate of coarse-grained ilmenite according to claim 1, characterized in that, In step 4, the coarse and fine classification of the ilmenite primary flotation concentrate is carried out by hydraulic classification, with a classification screen size of 0.075 mm, so that qualified coarse ilmenite particles are recovered in advance.

8. The flotation method for improving the recovery rate of coarse-grained ilmenite according to claim 1, characterized in that, The pH value of the second-stage flotation pulp of the ilmenite second-stage flotation raw material mentioned in step 5 is 7.5~8.0, and the ore-mineralization sequence of the flotation is returned.

9. The flotation method for improving the recovery rate of coarse-grained ilmenite according to claim 1, characterized in that, In step 5, the two-stage flotation roughing operation involves adding 300-400 g / t of water glass as a dispersant and adjusting the slurry for 5 minutes to ensure that the fine-grained ilmenite slurry system is fully dispersed. No water glass is required for the two-stage flotation cleaning operation.

10. The flotation method for improving the recovery rate of coarse-grained ilmenite according to claim 1, characterized in that, In steps 3 and 5, flotation is performed by skimming bubbles. The skimming is done using a flotation machine with a rotation speed of 1992 r / min.

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