Methods for improving the flotation recovery rate of valuable minerals through scavenging concentrate classification
By classifying the scavenging concentrate, coarse particles are regrinded and re-selected, while fine particles are returned to the preceding flotation process. This solves the problem of low recovery rate of coarse minerals and achieves efficient recovery of valuable minerals. It is applicable to the improvement of flotation processes for various minerals.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- CENT SOUTH UNIV
- Filing Date
- 2023-06-28
- Publication Date
- 2026-07-17
AI Technical Summary
In existing technologies, the recovery rate of coarse-grained minerals during flotation is low, mainly because coarse-grained minerals are difficult to float and are difficult to effectively recover when recycled back to previous flotation operations, resulting in the loss of valuable minerals.
The scavenging concentrate is classified, with coarse particles being regrinded and re-selected, while fine particles are returned to the preceding flotation operation. The classification process is used to fine-tune the flotation process in order to improve the recovery rate of valuable minerals.
Without altering the existing flotation process, it significantly improves the recovery rate of valuable minerals, and is particularly suitable for the recovery of sulfide ores such as copper, lead, zinc, nickel, and molybdenum, as well as oxide ores such as spodumene and lepidolite. Moreover, the equipment is simple and low in cost.
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Figure CN118635004B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to a method for improving the flotation recovery rate of valuable minerals by feeding coarse particles from scavenging concentrate into grinding instead of returning them directly as middlings to the flotation operation after classification. This method belongs to the field of mineral processing technology. Background Technology
[0002] With the continuous development of mineral resources, the processing scale of ore dressing plants is increasing. To save energy and reduce production, the grinding fineness is being increased as much as possible. At the same time, as the mining depth continues to extend, the hardness of the ore increases, making it increasingly difficult to grind. This results in increasingly coarser flotation feed particles and increasingly lower recovery rates of valuable minerals. The main reasons are: firstly, coarse particles have a large mass, and the difference between the buoyancy provided by the froth and the gravity acting on the coarse particles is small, increasing the difficulty of flotation, especially during circulation due to the influence of the slurry fluid; secondly, coarse ore contains many lean intergrowths, resulting in insufficient liberation of valuable minerals, a small interaction area with the collector, and weaker buoyancy lift, making flotation more difficult. These factors mean that even if coarse particles enter the flotation froth during scavenging operations, they are difficult to float when recycled back to previous flotation operations, ultimately ending up in the flotation tailings, resulting in the loss of valuable minerals. Therefore, developing new flotation processes to improve the efficient recovery rate of valuable minerals from coarse particles without changing the existing grinding fineness is of great significance. Summary of the Invention
[0003] To address the problem of unsatisfactory recovery of valuable minerals in existing scavenging concentrates, the present invention aims to provide a method for improving the flotation recovery rate of valuable minerals through a process of scavenging concentrate classification, coarse-grained regrinding and re-selection, and fine-grained return to the preceding flotation operation. This method aims to significantly improve the recovery rate of valuable minerals without significantly altering the existing flotation process.
[0004] A method for improving the flotation recovery rate of valuable minerals by classifying scavenging concentrate involves grinding and roughing the valuable minerals to obtain rough concentrate and roughing tailings. The roughing tailings are then subjected to scavenging to obtain scavenging concentrate. The scavenging concentrate is then classified to obtain coarse and fine particles. The coarse particles are then refmilled and re-selected, while the fine particles are returned as middlings to the preceding flotation operation.
[0005] This invention innovatively classifies scavenged concentrate and returns the fine particles from the classification to the previous stage of circulating flotation, while the coarse particles are regrinded and re-selected. In this way, valuable minerals in scavenged concentrate can be effectively recovered and the flotation recovery rate of valuable minerals can be improved by finely adjusting the existing flotation process.
[0006] In this invention, there are no special requirements for valuable minerals; for example, they can be any sulfide mineral and / or oxide mineral.
[0007] In this invention, the sulfide mineral is, for example, a sulfide mineral containing at least one metal selected from copper, lead, zinc, nickel, and molybdenum.
[0008] In this invention, the oxide mineral is, for example, at least one of spodumene, lepidolite, ilmenite, rare earth minerals, tungsten ore, fluorite, iron ore, and phosphate rock.
[0009] In this invention, scavenging concentrate can be obtained based on known methods, for example, it can be obtained through known grinding and roughing processes.
[0010] In this invention, the scavenged concentrate is scavenged concentrate 1, scavenged concentrate 2, scavenged concentrate 3, or a mixture thereof, preferably scavenged concentrate 1.
[0011] In this invention, the scavenging concentrate classification method can be known, for example, it can include hydrocyclone classification, screening classification, spiral classification, etc. In industrial production, hydrocyclone classification and high-frequency vibrating screen classification are preferred.
[0012] In this invention, after grading, the coarse particle product contains at least 45 wt% +120 mesh particles, preferably at least 75 wt%. In this invention, the +120 mesh particles refer to particles that pass through a 120 mesh sieve.
[0013] A preferred coarse particle regrinding and re-selection scheme of the present invention is shown in the following example process flow. Figure 1 (A) The coarse particles and coarse concentrate are mixed and then subjected to classification, regrinding, and reflotation. In a typical embodiment of this invention, coarse particles obtained from scavenging concentrate classification can be combined with the coarse concentrate, and simultaneous flotation can be achieved using conventional subsequent classification, regrinding, and flotation processes for the coarse concentrate. In this invention, mixing coarse particles and coarse concentrate for classification, regrinding, and reflotation is equivalent to reclassifying the coarse particles, reducing the amount of fine particles entering the regrinding process, and improving regrinding efficiency.
[0014] Another preferred embodiment of the present invention, namely coarse particle regrinding and re-selection, has a process flow as shown in the example below. Figure 1 (B) The coarse particles and coarse particles A after classification from the coarse concentrate are mixed and then regrinded and refloted. In this invention, the coarse particles and coarse particles A are combined and regrinded. After classification, the fine particles enter the flotation process, and the coarse particles B are returned to the regrinding operation.
[0015] Another embodiment of the present invention has the following process route: Figure 1 (C) The coarse particles are regrinded and classified separately. The resulting coarse particles C enter the regrinding process, while the fine particles are returned to the previous scavenging operation.
[0016] In this invention, the fine particles obtained from the scavenging concentrate classification are returned to the preceding flotation operation. For example, when the scavenging concentrate is scavenging grade 1 concentrate, the fine particles are returned to the roughing operation.
[0017] In this invention, the coarse particles of scavenging concentrate are regrinded and re-selected, while the fine particles are returned to the preceding flotation operation. This can significantly improve the recovery rate of valuable minerals without requiring major adjustments to the original process.
[0018] The beneficial effects of this invention are:
[0019] This invention classifies scavenging concentrate into coarse and fine particles. The coarse particles are regrinded and re-selected, while the fine particles are returned as middlings to the preceding flotation operation. Because the coarse particles do not enter the recycling process, they are less affected by the slurry fluid. Simultaneously, timely regrinding of the coarse particles ensures sufficient liberation of valuable minerals, resulting in adequate flotation enrichment and a significantly improved flotation recovery rate. This scavenging concentrate classification process is particularly suitable for recovering valuable minerals from the coarse particles of ores such as copper, lead, zinc, nickel, molybdenum, spodumene, lepidolite, ilmenite, rare earth ores, tungsten ores, fluorite, iron ore, and phosphate rock. Furthermore, this process only adds a classification step, requiring minimal investment, using simple and efficient equipment, and has low cost, making it a promising candidate for industrial application. Attached Figure Description
[0020] Figure 1 This is a diagram of the flotation process (including primary and secondary flotation) of the present invention.
[0021] Figure 2 This is a typical flotation process flow chart;
[0022] Figure 3 For the present invention Figure 1 Example of a flotation process in (A);
[0023] Figure 4 For the present invention Figure 1 (B) is an example of a flotation process;
[0024] Figure 5 For the present invention Figure 1 (C) is an example of a flotation process. Detailed Implementation
[0025] The following examples are intended to further illustrate the present invention, but not to limit the scope of protection of the present invention. Unless otherwise specified, all parts and percentages in the examples refer to mass.
[0026] This invention provides a method for improving the flotation recovery rate of valuable minerals through a process of scavenging concentrate classification, coarse-grained regrinding and re-selection, and fine-grained return to the preceding flotation operation. The scavenging concentrate is classified to separate coarse and fine particles. The coarse particles are then regrinded and re-selected, while the fine particles are returned to the preceding flotation operation as middlings.
[0027] The aforementioned scavenging concentrate classification process can be as follows: Figure 1 (A) or Figure 1 (B) or Figure 1 As shown in (C): In this invention, the coarse particle product obtained from scavenging concentrate classification is combined with the flotation rough concentrate, then classified, refmilled, and then separated by flotation (see...). Figure 1 (A)) can also be combined with the coarse particles in the flotation concentrate for regrinding and re-selection (see Figure 1 (B)), or grind and select separately (see Figure 1 (C)) is further preferably a process in which the coarse particles obtained from the scavenging concentrate classification are combined with the coarse particle products from the flotation rough concentrate and then regrinded and re-selected (see [C]). Figure 1 (B)).
[0028] In this invention, the scavenging concentrate classification method includes hydrocyclone classification, screening classification, spiral classification, etc. For industrial production, hydrocyclone classification and high-frequency vibrating screen classification are preferred. In this invention, after classification, the coarse particle product contains at least 45% (by mass) of +120 mesh particles, preferably at least 75% (by mass). In this invention, valuable mineral ores include sulfide ores such as copper, lead, zinc, nickel, and molybdenum, and oxide ores such as spodumene, lepidolite, ilmenite, rare earth ores, tungsten ores, fluorite, iron ore, and phosphate rock.
[0029] In this invention, the scavenged concentrate can be scavenged concentrate 1, scavenged concentrate 2, scavenged concentrate 3, or a mixture thereof, preferably scavenged concentrate 1.
[0030] Example 1: Flotation of a porphyry copper ore
[0031] A porphyry copper deposit contains 0.37% copper and 2.10% sulfur. The grinding fineness is -200 mesh, 61.5% of the ore is fined. The flotation concentration is 30%. The roughing lime dosage is 200 g / t. The pH value is 7.0. A combination collector of butyl xanthate and thiocyanate is used. Specific reagent dosages are shown in Table 1. Figure 2 The conventional flotation process yielded a copper grade of 5.09% and a copper recovery rate of 86.5% in the flotation concentrate. However, under the same reagent conditions (see Table 1), using… Figure 3 The flotation process, after classification through a 120-mesh sieve, yielded a copper grade of 5.21% and a copper recovery rate of 86.1% in the rough concentrate; and a copper grade of 1.32% and a copper recovery rate of 2.7% in the coarse particles; that is, the copper grade in the rough concentrate + coarse particles is 4.78% and the copper recovery rate is 88.8%. Figure 2 Compared with conventional flotation processes, the copper recovery rate is increased by 2.3 percentage points, which is a significant improvement.
[0032] Table 1. Dosage of flotation reagents in stage 1
[0033]
[0034] Next, Figure 2 The rough concentrate obtained from the conventional flotation process was classified, regrinded, and re-selected (flotation operation: primary separation, secondary cleaning, and secondary scavenging). The reagent dosages for the flotation operation are shown in Table 2. The copper grade in the resulting copper concentrate was 22.2%, and the copper recovery rate was 84.77%. [The remaining text appears to be incomplete and requires further context.] Figure 3 The rough concentrate and coarse particles obtained from the flotation process Figure 1 (B) shows the two-stage process flow for further processing (flotation operation: primary separation, secondary cleaning, and secondary scavenging). The reagent dosage for the flotation operation is shown in Table 2. The copper grade in the obtained copper concentrate is 22.1%, and the copper recovery rate is 87.11%. The new process achieves a higher copper flotation recovery rate than the conventional process.
[0035] Table 2. Dosage of Reagents for Second-Stage Flotation
[0036]
[0037] Example 2: Flotation of a porphyry copper ore
[0038] A porphyry copper deposit contains 0.37% copper and 2.10% sulfur. The grinding fineness is -200 mesh, 61.5% of the ore is fined. The flotation concentration is 30%. The roughing lime dosage is 200 g / t. The pH is 7.0. A combination collector of butyl xanthate and thiocyanate is used. Specific reagent dosages are shown in Table 1. Figure 2 The conventional flotation process yielded a copper grade of 5.09% and a copper recovery rate of 86.5% in the flotation concentrate. However, under the same reagent conditions (see Table 1), using… Figure 4 The flotation process, after classification through a 120-mesh sieve, yielded a copper grade of 5.41% and a copper recovery rate of 85.7% in the rough concentrate; a copper grade of 1.52% and a copper recovery rate of 2.6% in coarse particles 1; and a copper grade of 0.90% and a copper recovery rate of 0.7% in coarse particles 2. Therefore, the total copper grade of the rough concentrate + coarse particles 1 + coarse particles 2 is 4.91%, and the copper recovery rate is 89.0%. Figure 2 Compared with conventional flotation processes, the copper recovery rate is increased by 2.5 percentage points, which is a significant improvement.
[0039] Next, Figure 2 The rough concentrate obtained from the conventional flotation process was classified, regrinded, and re-selected (flotation operation: primary separation, secondary cleaning, and secondary scavenging). The reagent dosages for the flotation operation are shown in Table 2. The copper grade in the resulting copper concentrate was 22.2%, and the copper recovery rate was 84.77%. [The remaining text appears to be incomplete and requires further context.] Figure 4 The rough concentrate obtained from the flotation process + coarse particles 1 + coarse particles 2 are combined, classified, regrinded, and re-selected (e.g.) Figure 1 (A) (Flotation operation: primary separation, secondary cleaning, and secondary scavenging). The reagent dosage for the flotation operation is shown in Table 2. The copper grade in the obtained copper concentrate is 22.3%, and the copper recovery rate is 87.24%. The new process achieves a higher copper flotation recovery rate than the conventional process.
[0040] Example 3: Flotation of a porphyry copper ore
[0041] A porphyry copper deposit contains 0.37% copper and 2.10% sulfur. The grinding fineness is -200 mesh, 61.5% of the ore is fined. The flotation concentration is 30%. The roughing lime dosage is 200 g / t. The pH is 7.0. A combination collector of butyl xanthate and thiocyanate is used. Specific reagent dosages are shown in Table 1. Figure 2 The conventional flotation process yielded a copper grade of 5.09% and a copper recovery rate of 86.5% in the flotation concentrate. However, under the same reagent conditions (see Table 1), using… Figure 5 The flotation process, after classification through a 120-mesh sieve, yielded a copper grade of 5.62% and a copper recovery rate of 88.6% in the flotation rough concentrate, which is consistent with... Figure 2 Compared with conventional flotation processes, the copper recovery rate is increased by 2.1 percentage points, which is a significant improvement.
[0042] Next, Figure 2 The rough concentrate obtained from the conventional flotation process was classified, regrinded, and re-selected (flotation operation: primary separation, secondary cleaning, and secondary scavenging). The reagent dosages for the flotation operation are shown in Table 2. The copper grade in the resulting copper concentrate was 22.2%, and the copper recovery rate was 84.77%. [The remaining text appears to be incomplete and requires further context.] Figure 5 The rough concentrate obtained from the flotation process is classified, regrinded, and then re-selected (e.g.) Figure 1 (C) (Flotation operation: primary separation, secondary cleaning, and secondary scavenging). The reagent dosage for the flotation operation is shown in Table 2. The copper grade in the obtained copper concentrate is 23.6%, and the copper recovery rate is 86.92%. The new process achieves a higher copper flotation recovery rate than the conventional process.
[0043] Example 4: Flotation of a Fluorite Ore
[0044] A certain fluorite ore contains 37.2% fluorite, with a grinding fineness of -200 mesh accounting for 65.8%, a flotation concentration of 30%, a roughing sodium carbonate dosage of 600 g / t, and a pH value of approximately 8.2. Oleic acid is used as the collector, and water glass as the modifier. Specific reagent dosages are shown in Table 3. Figure 2 The conventional flotation process yielded a fluorite grade of 76.5% and a fluorite recovery rate of 86.8% in the flotation concentrate. However, under the same reagent conditions, using… Figure 3 The flotation process, after classification through a 120-mesh sieve, yielded a fluorite grade of 80.4% and a fluorite recovery rate of 83.4% in the rough concentrate; and a fluorite grade of 60.6% and a fluorite recovery rate of 12.8% in the coarse particles; that is, the combined fluorite grade of the rough concentrate and coarse particles was 74.6% and the fluorite recovery rate was 93.2%. Figure 2 Compared with conventional flotation processes, the fluorite recovery rate is increased by 6.4 percentage points, which is a significant improvement.
[0045] Table 3. Dosage of flotation reagents for stage 1
[0046]
[0047] Next, Figure 2 The rough concentrate obtained from the conventional flotation process was classified, regrinded, and re-selected (flotation operation: one separation, six cleaning processes, and two scavenging processes). The reagents required for the flotation operation and their dosages are shown in Table 4. The fluorite grade in the obtained fluorite concentrate was 97.4%, and the fluorite recovery rate was 80.4%. Figure 3 The rough concentrate and coarse particles obtained from the flotation process Figure 1 (B) shows the two-stage process flow for further processing (flotation operation: primary separation, six cleaning processes, and secondary scavenging). The reagents required for the flotation operation and their dosages are shown in Table 4. The fluorite grade in the obtained fluorite concentrate is 97.5%, and the fluorite recovery rate is 85.7%. The new process achieves a higher fluorite flotation recovery rate than the conventional process.
[0048] Table 4. Dosage of Reagents for Second-Stage Flotation
[0049]
[0050]
[0051] In summary, the method for improving the flotation recovery rate of valuable minerals by using the scavenging concentrate classification-coarse-grained regrinding and re-selection-fine-grained return to the preceding flotation operation process described in this invention only requires minor adjustments to the existing flotation process to significantly improve the recovery rate of valuable minerals.
Claims
1. A method for improving the flotation recovery rate of valuable minerals through scavenging concentrate classification, comprising grinding and roughing the valuable minerals to obtain a rough concentrate and roughing tailings, and then subjecting the roughing tailings to scavenging treatment to obtain a scavenging concentrate, characterized in that, The scavenging concentrate is classified into coarse and fine particles. The coarse particles are regrinded and re-selected, while the fine particles are returned as middlings to the previous flotation operation. The valuable minerals mentioned are sulfide minerals and / or oxide minerals; The sulfide ore is a sulfide ore containing at least one metal selected from copper, lead, zinc, nickel, and molybdenum; The oxide ore is at least one of spodumene, lepidolite, ilmenite, rare earth ore, tungsten ore, fluorite, and phosphate rock; After grading, +120 mesh particles account for more than 75 wt% of the coarse particle product.
2. The method as described in claim 1, characterized in that, The scavenging concentrate is scavenging concentrate 1, scavenging concentrate 2, scavenging concentrate 3, or a mixture thereof.
3. The method as described in claim 1, characterized in that, Scavenging concentrate classification methods include hydrocyclone classification, screening classification, or spiral classification.
4. The method as described in claim 3, characterized in that, Classification methods for scavenging concentrates include hydrocyclone classification and high-frequency vibrating screen classification.
5. The method according to any one of claims 1 to 4, characterized in that, The coarse particles and coarse concentrate are mixed and then subjected to classification, regrinding and flotation.
6. The method according to any one of claims 1 to 4, characterized in that, The coarse particles and the coarse particles after the coarse concentrate classification are mixed and then subjected to regrinding and refloating.
7. The method according to any one of claims 1 to 4, characterized in that, The coarse particles are re-ground and re-selected separately.