CN112246455A - Grading coarse sand granularity control method for tailing damming cyclone - Google Patents
Grading coarse sand granularity control method for tailing damming cyclone Download PDFInfo
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- CN112246455A CN112246455A CN202011107986.4A CN202011107986A CN112246455A CN 112246455 A CN112246455 A CN 112246455A CN 202011107986 A CN202011107986 A CN 202011107986A CN 112246455 A CN112246455 A CN 112246455A
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- B04—CENTRIFUGAL APPARATUS OR MACHINES FOR CARRYING-OUT PHYSICAL OR CHEMICAL PROCESSES
- B04C—APPARATUS USING FREE VORTEX FLOW, e.g. CYCLONES
- B04C11/00—Accessories, e.g. safety or control devices, not otherwise provided for, e.g. regulators, valves in inlet or overflow ducting
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Abstract
The invention relates to the technical field of cyclone application, in particular to a tailing damming cyclone classification coarse sand granularity control method, which is characterized by comprising the following steps: the method comprises the following steps: selecting a section of swirler; step two: setting working state parameters, and after selecting the first section of the cyclone in the step I, adopting the working state parameters in the sorting process as follows: the mass concentration of the feeding ore pulp of the first-stage cyclone is 30-35%, the feeding pressure of the first-stage cyclone is 70-100kPa, the feeding pressure is the inlet pressure of the feeding pipe, the tailing ore pulp is fed into the first-stage cyclone in the first step for classification under the conditions of the mass concentration of the ore pulp and the feeding pressure, the classified underflow product is used as coarse sand for damming, the classified overflow product is fine sand, and the fine sand is discharged into a tailing pond.
Description
Technical Field
The invention relates to the technical field of cyclone application, in particular to a method for controlling the grading coarse sand granularity of a tailing damming cyclone, which has the advantages of simple process, low investment, low cost and high grading coarse sand yield.
Background
As is well known, cyclones are widely used in mining, metallurgy, environmental protection, petroleum, chemical and food industries. The cyclone usually uses water as a medium, and depends on an external pump or a gravity field to transmit power, and a rotary flow field can accelerate the settling velocity of solid-phase particles in a water medium and increase the difference of the settling velocity of coarse and fine particles in the water medium, so that the rapid separation and classification of particles with different sizes are realized.
The dam construction of cyclone classification tailings is an important method for the tailing construction in the mineral separation industry. The process is roughly as follows: coarse sand obtained after the tailing pulp is subjected to coarse and fine classification by a cyclone is used for damming, the dam body of the damming of the coarse tailing sand classified by the cyclone has good stability, a natural beach surface can be formed, the engineering quantity can be reduced, and fine sand classified by the cyclone is conveyed into a tailing pond. The production unit generally requires that the content of plus 200 meshes of coarse sand is more than 75 percent for the dam construction coarse sand granularity, and also requires that the content of plus 200 meshes of coarse sand is more than 85 percent for the factory selection. The higher the content of +200 meshes required by dam construction on the coarse sand granularity is, the greater the difficulty in classifying the cyclone is, and sometimes two-section cyclone classification is needed when one section of cyclone can not meet the fineness requirement. For example, the requirement of the grit size of the dam-building coarse sand in the Delphine copper mine No. 4 tailing pond is that the grit size is more than 85% in the case of +200 meshes, the production adopts two-section FX660 cyclone classification, the underflow coarse sand of the first-section cyclone is diluted by adding water and is subjected to size mixing, then the underflow coarse sand of the second-section cyclone is fed into the second-section FX660 cyclone classification, the underflow coarse sand of the second-section cyclone is used for building a dam by a midline method. For another example, the diqing colored copper mine jade Raney tailing pond requires that the sum of the damming coarse sand and 200 meshes is more than 80%, and two sections of cyclones are adopted for classification at present.
However, in actual production, the coarse sand yield of the two-stage cyclone classification damming is often lower, and the requirement of production units on the coarse sand yield is often not met. This is because the two-stage staged cyclone process is more complex, and it is difficult to maximize the energy efficiency of each cyclone stage in production, so the yield of the comprehensive coarse sand is often lower than the design value. Moreover, the two-stage damming process has long flow, and relates to a plurality of cyclones and large workload of manual maintenance.
Disclosure of Invention
The invention aims to solve the defects of the prior art and provides the method for controlling the grading coarse sand granularity of the tailing damming cyclone, which has the advantages of simple process, low investment, low cost and high grading coarse sand yield.
The technical scheme adopted by the invention for solving the technical problems is as follows:
a tailing damming cyclone classification coarse sand granularity control method is characterized by comprising the following steps:
the method comprises the following steps: selecting a section of swirler, wherein the structure of the section of swirler comprises a feeding pipe, a cylinder, a cone, an overflow pipe and a bottom flow port, the side wall of the cylinder is connected with the feeding pipe, the upper end of the cylinder is provided with the overflow pipe, the lower end of the overflow pipe extends into the cylinder, the upper end of the overflow pipe extends out of the upper part of the cylinder, the lower end of the cylinder is connected with the cone, the outlet at the lower end of the cone is the bottom flow port, the specification selection parameter of the swirler is that the internal diameter of the cylinder is 500mm, the internal diameter of the equivalent circle of the feeding pipe is 130-170mm, the cylinder height is 500-1200mm, the cone angle is 45 degrees, the internal diameter of the overflow pipe is 150-200 mm;
step two: setting working state parameters, and after selecting a section of the cyclone with the parameters in the step one, adopting the working state parameters in the sorting process as follows: the mass concentration of feed ore pulp of the first-stage cyclone is 30-35%, the feeding pressure of the first-stage cyclone is 60-100kPa, the feeding pressure is the inlet pressure of a feed pipe, the tailing ore pulp is fed into the first-stage cyclone in the first step for classification under the conditions of the mass concentration of the ore pulp and the feeding pressure, the classified underflow product is used as coarse sand for damming, and the classified overflow product is fine sand and is discharged into a tailing pond.
In the first step of the invention, the height of the cylinder is optimized to 800 mm.
In step one of the process of the present invention, the inside diameter of the equivalent circle of the feed pipe is optimized to 165 mm.
The internal diameter of the overflow tube in step one of the present invention is optimized to be 180 mm.
In the first step of the invention, the internal diameter of the underflow opening is optimized to be 100 mm.
The feed pressure in step one of the present invention is optimized to 80 kPa.
By adopting the steps, the invention realizes the purpose of meeting the requirement of a production unit on the coarse sand granularity of the dam construction cyclone by adopting the first-stage cyclone for classification, saves more equipment and labor investment cost, has higher yield of classified coarse sand, and has the advantages of simple process, low investment, low cost, high yield of classified coarse sand and the like.
Drawings
FIG. 1 is a graph of data from experiments with different feed concentrations.
Fig. 2 is a data curve of different experimental results of feed pressure.
Fig. 3 is a graph of data from different cone angle experiments.
FIG. 4 is a graph of experimental data for different underflow port diameters.
Detailed Description
The invention is further described below with reference to the accompanying drawings:
as shown in the attached drawing, the method for controlling the classification grit size of the tailing damming cyclone is characterized by comprising the following steps:
the method comprises the following steps: selecting a section of swirler, wherein the structure of the section of swirler comprises a feeding pipe, a cylinder, a cone, an overflow pipe and a bottom flow port, the side wall of the cylinder is connected with the feeding pipe, the upper end of the cylinder is provided with the overflow pipe, the lower end of the overflow pipe extends into the cylinder, the upper end of the overflow pipe extends out of the upper part of the cylinder, the lower end of the cylinder is connected with the cone, the outlet at the lower end of the cone is the bottom flow port, the specification selection parameter of the swirler is that the internal diameter of the cylinder is 500mm, the internal diameter of the equivalent circle of the feeding pipe is 130-170mm, the cylinder height is 500-1200mm, the cone angle is 45 degrees, the internal diameter of the overflow pipe is 150-200 mm;
step two: setting working state parameters, and after selecting a section of the cyclone with the parameters in the step one, adopting the working state parameters in the sorting process as follows: the mass concentration of feed ore pulp of the first-stage cyclone is 30-35%, the feeding pressure of the first-stage cyclone is 70-100kPa, the feeding pressure is the inlet pressure of a feed pipe, the tailing ore pulp is fed into the first-stage cyclone in the first step for classification under the conditions of the mass concentration of the ore pulp and the feeding pressure, the classified underflow product is used as coarse sand for damming, and the classified overflow product is fine sand and is discharged into a tailing pond.
Further, in the first step, the height of the cylinder is optimized to 800 mm.
Further, in the first step, the equivalent circle inner diameter of the feeding pipe is optimized to be 165 mm.
Further, the inner diameter of the overflow pipe in the first step is optimized to be 180 mm.
Further, the inner diameter of the underflow opening in the first step is optimized to be 100 mm.
Further, the feeding pressure in the first step is optimized to be 80 kPa.
The invention adopts a cyclone with the internal diameter of 500mm of a cylinder body, and combines with the cone angle of 45 degrees, the quality concentration of fed ore pulp, the feeding pressure of a section of the cyclone and other parameters of the cyclone to obtain an optimized scheme, the small diameter of the cylinder body of the cyclone can cause low single machine processing capacity, more cyclones are required to be connected in parallel to improve the processing capacity, the working difficulty of maintenance and management is increased, the large diameter of the cyclone can cause poor final cyclone result, the occupied space is also increased, the equipment operation cost is increased, the self weight of the equipment is larger, and the equipment is inconvenient to transfer and maintain on a tailing dam High yield of the classified coarse sand and the like.
Examples
An industrial experiment for tailing damming of a cyclone with the inner diameter of 500mm in a section of cylinder is carried out on a certain large copper ore, and an industrial experiment result proves that the cyclone with the inner diameter of 500mm in the section of cylinder has a grading effect superior to that of the damming of the original two sections of cyclones under the conditions of proper feeding concentration, pressure and equipment structure parameters. The relevant cases are introduced as follows:
the bottom flow coarse sand of the first cyclone is diluted by adding water and is subjected to size mixing, and then is fed into the second cyclone for classification, and the bottom flow of the second cyclone is used as coarse sand for damming. The first stage cyclone specification was ɸ 420mm cyclone, operating pressure 70 kPa. The specification of the secondary cyclone is ɸ 250mm, and the operating pressure of the secondary cyclone is 75 kPa. 35 +/-2% of tailings plus 200-mesh granularity, the content of coarse sand plus 200-mesh granularity is required to be more than 80%, the yield of final underflow coarse sand is required to be more than 23%, and the production indexes are shown in the following table 1, and the yield of coarse sand is only about 20.41%.
TABLE 1 data of dam construction of two-stage cyclone for present tailings of certain copper mine
The cyclone with the internal diameter of 500mm in a section of cylinder body adopted by the invention is subjected to tailing damming industrial test on the site, and underflow coarse sand of the cyclone is used for damming. The content of normal production tailing granularity plus 200-mesh granularity is 35 +/-2%, the feeding concentration of tailing pulp is adjusted to be 30-35%, and the parameters of a swirler are set as follows: under the conditions of a cone angle of 45 degrees, a bottom flow port of 100mm and an operating pressure of 80kPa, the sum of underflow grit of the cyclone and 200 meshes of fineness is 82.73 percent, the yield of the underflow grit is 27.62 percent, the requirement of the yield of the minimum 23 percent of produced grit is met and exceeded, and the data of the investigation of industrial test data are shown in the following table 2.
TABLE 2 one-section ɸ 500mm cyclone damming industry test data
Example 2:
an industrial experiment for tailing damming of a cyclone with the inner diameter of 500mm in a section of cylinder is carried out on a certain large copper ore, and an industrial experiment result proves that the cyclone with the inner diameter of 500mm in the section of cylinder has a grading effect superior to that of the damming of the original two sections of cyclones under the conditions of proper feeding concentration, pressure and equipment structure parameters. And the optimal feed concentration, pressure conditions and plant design parameters are summarized.
(1) Feed concentration selection
The appropriate feed concentration selection is with respect to the cyclone. The concentration influences the grading effect of the cyclone, the lower the concentration is, the better the grading effect of the cyclone is, and the higher the grading concentration is, the more difficult the coarse sand product index is to ensure. However, the lower the classification concentration, the larger the water amount in the ore pulp, which easily causes the transportation flow rate to be too large, the production water requirement to be too large and the equipment type selection processing capacity to be large, so that the lower the classification concentration is, the better the classification concentration is. Concentration tests of three graded concentration intervals of 30-35%, 35-40% and 40-45% are carried out, a bottom flow port is selected to be 90mm, a cone angle is 45 degrees, and the running pressure is 80kpa, and test results prove that the effect of the feed concentration of 30-35% is the best. The experimental data are shown in figure 1.
From the test results in fig. 1, it can be seen that the three concentration conditions respectively meet the concentration ranges of 30-35%, 35-40% and 40-45%, and from the view point of the underflow coarse sand particle size content, the higher the feed concentration is, the lower the content of the fraction of +200 mesh in the underflow coarse sand is, wherein when the feed concentration reaches 43.50% (40-45% concentration) the requirement that the particle size of the coarse sand +200 mesh is less than or equal to 80% is met. In terms of the yield of the underflow grit, the yield of the underflow grit of the cyclone is reduced from 24.69% to 16.47% along with the continuous increase of the feed concentration, which shows that the yield of the grit is lower as the feed concentration is higher, and the grading effect is less ideal. From experimental data, the raw sand size and yield index of the feed concentration of 32.31% (30-35% concentration) can meet the field production requirement, and further reduction of the feed concentration will increase the production cost, so that further reduction of the feed concentration is not needed.
(2) Selection of operating pressure
The operating pressure is an important parameter of the operation of the cyclone, the higher the operating pressure is, the larger the processing capacity of the cyclone is, the higher the internal centrifugal strength is, the better the grading effect is, the grading energy consumption can be increased, the more serious the abrasion to pipelines and equipment is, and therefore, the larger the pressure is, the better the pressure is. A section of ɸ 500mm cyclone pressure condition test comparison is carried out under the conditions of 30-35% feed concentration, 45-degree cone angle and 90mm bottom flow port parameters. The experimental data are shown in figure 2.
From the test results in fig. 2, it can be seen that the content of underflow grit +200 mesh tends to increase and then to stabilize as the feed pressure of the cyclone increases; the underflow grit yield also shows a tendency to increase rapidly and then to stabilize. The pressure is increased to improve the grading effect, but the improvement range of the grading effect is reduced after the pressure reaches a certain degree. The optimum operating pressure in the test was 80 kPa.
(3) Selection of cone angle of cone
The cone angle of the cyclone has obvious influence on the grading particle size control, the cone angle of the cyclone refers to the included angle of the extension lines of the side walls of the cones at two sides, the larger the cone angle is, the better the control on the underflow grit size is, but the yield of the underflow grit is reduced, so the larger the cone angle is, the better the underflow grit yield is. In the industrial test, under the conditions of the feeding concentration of 30-35% and the pressure of 80kpa, 20-degree cones, 30-degree cones, 45-degree cones and 60-degree cones are compared, the size of the underflow opening is adjusted to enable the grit size of the underflow to reach a level slightly larger than 80% of +200 meshes, and compared with the yield of the underflow grit at different cone angles, the higher the yield is, the better the grading effect is. The final indexes of grit fineness and grit yield of the cone angle of 45 degrees are superior to those of other 3 cone angles. The experimental data are shown in figure 3.
From the experimental results in fig. 3, it can be seen that the underflow grit yield increases and then decreases as the cone angle of the cyclone increases. The 45-degree cone structure has the highest yield of the underflow grit in the test, and the yield of the underflow grit reaches 31.82 percent, which is higher than the yield of the grit required by the production and is not lower than 23 percent. The optimum swirler cone angle is therefore a 45 ° cone.
(4) Underflow port size selection
The size of the underflow opening of the cyclone affects the content of the underflow grit with the granularity of +200 meshes and the yield of the grit, and according to general experience, the larger the diameter of the underflow opening is, the higher the yield of the underflow is, the lower the content of the underflow with the granularity of +200 meshes is, and therefore, the larger the diameter of the underflow opening is, the better the underflow opening is. Therefore, in the industrial test, five indexes of 80/90/100/110/120mm bottom flow openings with specifications are compared under the conditions of 30-35% of feeding concentration, 80kpa of pressure and 45-degree cone, and finally 100mm is selected as the bottom flow opening with the optimal size. The test results are shown in FIG. 4.
From the test results in fig. 4, as the diameter of the underflow opening of the cyclone increases, the content of the underflow grit +200 meshes tends to decrease monotonically, and the yield of the underflow grit tends to increase monotonically. Considering that the requirement of underflow grit plus 200 meshes is more than 80 percent, the yield is more than 23 percent, so the diameter of the maximum underflow port meeting the requirement is 110mm, but because the 110mm underflow port is close to the required boundary condition, and considering that the underflow port belongs to a wear part in practical application, the diameter of the underflow port becomes larger in continuous wear, so the 100mm underflow port is more suitable for industrial application.
Claims (6)
1. A tailing damming cyclone classification coarse sand granularity control method is characterized by comprising the following steps:
the method comprises the following steps: selecting a section of swirler, wherein the structure of the section of swirler comprises a feeding pipe, a cylinder, a cone, an overflow pipe and a bottom flow port, the side wall of the cylinder is connected with the feeding pipe, the upper end of the cylinder is provided with the overflow pipe, the lower end of the overflow pipe extends into the cylinder, the upper end of the overflow pipe extends out of the upper part of the cylinder, the lower end of the cylinder is connected with the cone, the outlet at the lower end of the cone is the bottom flow port, the specification selection parameter of the swirler is that the internal diameter of the cylinder is 500mm, the internal diameter of the equivalent circle of the feeding pipe is 130-170mm, the cylinder height is 500-1200mm, the cone angle is 45 degrees, the internal diameter of the overflow pipe is 150-200 mm;
step two: setting working state parameters, and after selecting a section of the cyclone with the parameters in the step one, adopting the working state parameters in the sorting process as follows: the mass concentration of feed ore pulp of the first-stage cyclone is 30-35%, the feeding pressure of the first-stage cyclone is 70-100kPa, the feeding pressure is the inlet pressure of a feed pipe, the tailing ore pulp is fed into the first-stage cyclone in the first step for classification under the conditions of the mass concentration of the ore pulp and the feeding pressure, the classified underflow product is used as coarse sand for damming, and the classified overflow product is fine sand and is discharged into a tailing pond.
2. The method for controlling the graded grit size of a tailing damming cyclone according to claim 1, wherein in the first step, the height of the cylinder is optimized to 800 mm.
3. The method for controlling the size of the graded coarse particles of the tailing damming cyclone according to claim 1, wherein the inside diameter of the equivalent circle of the feeding pipe in the first step is optimized to 165 mm.
4. The method for controlling the classifying grit size of a tailing damming cyclone according to claim 1, wherein the internal diameter of the overflow pipe in the first step is optimized to 180 mm.
5. The method for controlling the graded grit size of a tailing damming cyclone according to claim 1, wherein the inner diameter of the underflow opening in the first step is optimized to be 100 mm.
6. The method for controlling the classifying grit size of the cyclone for damming tailings according to claim 1, wherein the feeding pressure of the cyclone at the first stage in the second step is optimized to 80 kPa.
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Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103008122A (en) * | 2012-12-28 | 2013-04-03 | 刘晔 | Swirler |
| CN103394404A (en) * | 2013-08-15 | 2013-11-20 | 太原钢铁(集团)有限公司 | Ore grinding classification equipment |
| CN103936345A (en) * | 2014-03-03 | 2014-07-23 | 中钢矿业开发有限公司 | Method and system for preparing tailings filling slurry |
| CN110318369A (en) * | 2018-03-29 | 2019-10-11 | 南京梅山冶金发展有限公司 | The high tailings impoundment of microfine containing mud and technique of building a dam |
| CN111437982A (en) * | 2020-04-08 | 2020-07-24 | 云南磷化集团有限公司 | Method for reducing fine ratio of sand setting to mineral grinding and grading capacity |
-
2020
- 2020-10-16 CN CN202011107986.4A patent/CN112246455A/en active Pending
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN103008122A (en) * | 2012-12-28 | 2013-04-03 | 刘晔 | Swirler |
| CN103394404A (en) * | 2013-08-15 | 2013-11-20 | 太原钢铁(集团)有限公司 | Ore grinding classification equipment |
| CN103936345A (en) * | 2014-03-03 | 2014-07-23 | 中钢矿业开发有限公司 | Method and system for preparing tailings filling slurry |
| CN110318369A (en) * | 2018-03-29 | 2019-10-11 | 南京梅山冶金发展有限公司 | The high tailings impoundment of microfine containing mud and technique of building a dam |
| CN111437982A (en) * | 2020-04-08 | 2020-07-24 | 云南磷化集团有限公司 | Method for reducing fine ratio of sand setting to mineral grinding and grading capacity |
Non-Patent Citations (1)
| Title |
|---|
| 刘亚兴等: "水力旋流器沉砂筑坝的试验研究", 《金属矿山》 * |
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Application publication date: 20210122 |