Low-grade ore low-consumption high-efficiency crushing and grinding and pre-selection and waste throwing integrated treatment method and special system thereof

Abstract

The application discloses a kind of low-grade ore low consumption high efficiency breaking and grinding and preselection throw waste integrated processing method and its special system, belong to the technical field of mineral processing, the core technological process of the present application uses "two-stage crushing+high pressure roller grinding+ray preselection throw waste+one-stage grinding", first, the raw ore is crushed to the particle size suitable for high pressure roller grinding by two-stage open circuit crushing;Subsequently, high pressure roller grinding is used for laminated crushing, which produces a large number of internal microcracks and promotes mineral dissociation along the grain boundary;After screening, the roller grinding product is sent to the ray separation equipment, and the dissociated low-grade waste rock and gangue are efficiently removed, which significantly improves the grinding grade;The concentrate after throwing waste is combined with the undersize product and enters the one-stage closed-circuit grinding, which is ground to the required fineness for flotation. This method greatly shortens the process, reduces equipment investment, energy consumption and steel consumption, reduces the grinding amount and the mud phenomenon from the source, improves the overall separation efficiency and resource utilization, and has significant economic benefits.

Description

Technical Field

[0001] This invention belongs to the technical field of mineral processing, specifically relating to an integrated method and system for low-grade ore with low consumption, high efficiency, crushing, grinding, pre-selection, and waste disposal. Background Technology

[0002] Skarn-type ores often contain various useful minerals such as copper, iron, tungsten, and molybdenum, but their raw ore grade is usually low, the useful minerals are unevenly distributed in particle size, and the ore dilution rate is high. The conventional crushing and grinding process for processing such low-grade ores both domestically and internationally is mostly "three-stage closed-circuit crushing (coarse crushing, medium crushing, fine crushing, and screening closed-circuit) + two-stage closed-circuit grinding (coarse grinding, fine grinding, and classification closed-circuit)". This process is technically mature and widely used, but its inherent drawbacks are becoming increasingly apparent when processing low-grade, difficult-to-process ores. For example: 1. The process is lengthy and the investment cost is high. The process includes multiple crushers and mills, and the types and quantities of supporting conveying, screening, and classification equipment are numerous, resulting in a long production line, a large footprint, and high investment in infrastructure and equipment. 2. Huge energy and steel consumption: Crushing and grinding operations are the "energy hogs" of the concentrator, accounting for approximately 50% to 70% of the total energy consumption of the concentrator, with grinding energy consumption accounting for over 80% of the total crushing and grinding energy consumption. The lengthy process, especially the two-stage grinding, results in persistently high energy consumption per unit of ore. Simultaneously, the consumption of grinding media (steel balls, liners) represents a significant operating cost. 3. Severe over-grinding and mud formation: Traditional ball mills primarily rely on impact and grinding, resulting in relatively low crushing efficiency and low energy utilization. More importantly, their crushing method makes it difficult to precisely control product particle size. Over-grinding is easily caused in low-hardness, brittle gangue minerals (such as calcite and quartz), and it also leads to mud formation of some valuable minerals. The resulting large quantities of fine-grained (-10μm or -20μm) minerals have high surface energy, making separation difficult and recovery rates low. This not only causes metal loss but also increases reagent consumption in subsequent separation operations (such as flotation) and the difficulty of wastewater treatment. 4. Uneven particle size distribution in the final product and low separation efficiency: Conventional processes result in a wide range of grinding product particle sizes, exhibiting a "coarse at both ends" phenomenon: the coarse particles have not yet fully liberated the valuable minerals from the gangue, while the fine particles have already been over-ground. This uneven particle size distribution severely affects the efficiency of flotation and other physicochemical separation operations, making it difficult to simultaneously improve concentrate grade and recovery rate. 5. Difficulty in pre-disposal and poor economic benefits: For low-grade ores, pre-disposal before crushing and grinding is an effective way to reduce costs. However, in traditional processes, directly discarding large pieces of raw ore (such as through hand sorting or heavy media separation) leads to a significant loss of metals in the waste rock due to the extremely low degree of liberation of valuable minerals, resulting in a sharp decline in recovery rate. If disposal is delayed until after fine crushing, most of the energy consumption has already occurred, significantly reducing energy-saving effects. Therefore, finding a pre-disposal node in traditional processes that is "early, accurate, and with minimal loss" is extremely difficult.

[0003] High-pressure roller mills, as a highly efficient pulverizing device, exhibit significant advantages in energy saving and microcrack generation due to their "laminated pulverization" principle. X-ray separation technology (such as XRT) has been applied in the mining industry in recent years, enabling the separation of lumpy materials based on compositional differences. However, a mature and systematic solution is still lacking in current technologies for organically combining high-pressure roller mills with X-ray separation technology and seamlessly integrating them into the grinding process to form a holistic, optimized, integrated treatment solution for low-grade ores, replacing the lengthy and energy-intensive traditional process. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a low-consumption and high-efficiency integrated method and system for crushing, grinding and pre-selection of low-grade ore and waste disposal, so as to solve the problems mentioned in the background art or achieve better technical effects.

[0005] To solve the above-mentioned technical problems, the inventors, through practice and summarization, derived the technical solution of this invention. This invention discloses a low-consumption, high-efficiency crushing, grinding, pre-selection, and waste disposal integrated treatment method for low-grade ores, the steps of which are as follows:

[0006] S1: After the raw ore is crushed into coarse and medium crushing in sequence, medium crushed ore is obtained;

[0007] S2: The medium-crushed ore obtained in S1 is fed into a high-pressure roller mill. After being milled by the high-pressure roller mill, a cake with internal micro-cracks is formed.

[0008] S3: The pressed cake obtained in S2 is broken up, and then the broken material is fed into the second screening device. Through screening, three different particle sizes of material are obtained: coarse, medium and fine.

[0009] Among them, the coarse-grained material is returned to the high-pressure roller mill to form a closed loop;

[0010] Medium-sized materials are selected as the target materials for pre-selection and disposal.

[0011] Fine-grained materials are directly conveyed to the pre-grinding mixing tank for subsequent grinding operations;

[0012] S4: Feed medium-sized material into the X-ray separator, identify it through X-ray transmission, set the sorting threshold, and use high-pressure air nozzles to blow out the identified waste rock;

[0013] S5: The concentrate obtained from the S4 ray separation is combined with the fine-grained material obtained from the S3 screening. The combined material is fed into a ball mill. After being milled by the ball mill, it is conveyed to the classification device. The overflow product obtained after classification cyclone is sent to the flotation operation, and the sediment obtained from the classification cyclone is returned to the ball mill.

[0014] Furthermore, in S1, after coarse and medium crushing, the particle size of the medium crushed ore is 40~70mm.

[0015] Furthermore, in step S2, the operating pressure of the high-pressure roller mill is set to 5.5~5.8 N / mm. 2 The roll gap is 15mm.

[0016] Furthermore, in S3, the second screening device is a double-layer vibrating screen with screen aperture sizes of 30mm and 10mm respectively.

[0017] Furthermore, in S3, the coarse-grained material has a particle size of +30mm, accounting for 5% of the total; the medium-grained material has a particle size of 10~30mm, accounting for 45% of the total; and the fine-grained material has a particle size of -10mm, accounting for 50% of the total.

[0018] Furthermore, in S4, the airflow injection of the high-pressure air nozzle is controlled by a high-speed solenoid valve, and the pulse width of a single injection is approximately 20~40ms.

[0019] Furthermore, in S5, 70% of the overflow fineness of the hydrocyclone in the grading device is -0.074mm, and the grade of the feed after mixing is 0.3%.

[0020] Furthermore, the dedicated system for the integrated treatment method of low-grade ore with low consumption and high efficiency crushing, grinding and pre-selection waste disposal as described above includes a first crushing mechanism, a second crushing mechanism, a high-pressure roller mill mechanism, a sorting mechanism and a grinding mechanism connected in sequence.

[0021] The first crushing mechanism includes a coarse crushing device, which crushes the raw ore into coarse ore with a particle size of 200-250mm after it is transported into the coarse crushing device; the second crushing mechanism includes a medium crushing device, which can further crush the coarse ore into medium ore with a particle size of 40-70mm.

[0022] Furthermore, the dedicated system also includes a first screening device connected between the second crushing mechanism and the high-pressure roller mill mechanism. The first screening device includes a buffer bin and a quantitative feeder. The middlings obtained from the two crushing stages enter the buffer bin through a pipeline, and are then transported to the quantitative feeder through a pipeline. The quantitative feeder stably feeds middlings of suitable particle size to the subsequent high-pressure roller mill mechanism.

[0023] Furthermore, the sorting mechanism includes a second screening device and a radiation separator. The second screening device and the radiation separator are connected by a high-pressure roller mill and an intermediate particle size product conveying channel. The material compacted by the high-pressure roller mill is then dispersed and fed into the second screening device, where it is screened by a double-layer vibrating screen to obtain materials of different particle sizes.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0025] (1) The present invention adopts “two-stage crushing + high-pressure roller mill + one-stage grinding” instead of “three-stage crushing + two-stage grinding”, which reduces the number of equipment sets, simplifies the process, shortens the production line, and significantly reduces equipment investment, civil engineering costs and land area.

[0026] (2) With the introduction of high pressure roller mill, the high efficiency and energy-saving characteristics of this invention can reduce the total power consumption of grinding by 15% to 30%; by pre-selecting by rays, 20% to 40% of waste stone is removed, which reduces the amount of material that needs to be ground from the source, and reduces the energy consumption of grinding and the consumption of steel balls and liners by 20% to 40%, and the overall energy saving and consumption reduction effect is extremely significant.

[0027] (3) The high-pressure roller mill of the present invention has the characteristics of lamination and crushing, and the early removal of gangue that is easy to muddy. The dual effect makes the content of -10μm fine particles in the final grinding product significantly reduced, the over-crushing of useful minerals is effectively controlled, and the product particle size distribution is uniform, laying a good foundation for efficient separation.

[0028] (4) In this invention, after high-pressure roller milling and before grinding, waste rock is removed by radiation at the "gold particle size" of 10~30mm. At this time, some useful minerals have been dissociated due to microcracks. The waste removal accuracy is high and the metal loss is small. This realizes the maximum removal of waste rock before the most energy-consuming grinding operation, directly reducing the cost of processing per ton of ore, improving the grade of feed, and thus improving the processing capacity and concentrate quality of subsequent sorting operations.

[0029] (5) The method disclosed in this invention is particularly suitable for the processing of low-grade, complex and difficult-to-process ores, enabling the economic and efficient development of mineral resources that were previously difficult to utilize due to poor economic efficiency, extending the service life of mines, and conforming to the sustainable development concept of green mining. Through the innovative integration of the process flow, the high-pressure roller mill technology and the X-ray pre-selection waste disposal technology are deeply integrated at the optimal node, forming a complete, efficient and energy-saving new paradigm for low-grade ore processing, which has broad industrial application prospects. Attached Figure Description

[0030] Figure 1 This is a process flow diagram of the integrated treatment method for low-grade ore with low consumption, high efficiency, crushing, grinding, pre-selection, and waste disposal according to the present invention.

[0031] Figure 2 This invention is a dedicated system for the integrated treatment of low-grade ore with low consumption, high efficiency, crushing, grinding, pre-selection, and waste disposal.

[0032] in:

[0033] 1. Raw ore feeder;

[0034] 2. Coarse crushing device;

[0035] 3. Medium crushing device;

[0036] 4. First screening device; 401. Buffer ore bin; 402. Quantitative feeder;

[0037] 5. High-pressure roller mill;

[0038] 6. High-pressure roller rear coarse particle product conveying channel;

[0039] 7. Second screening device;

[0040] 8. Conveying channel for intermediate particle size products after high-pressure roller;

[0041] 9. X-ray sorting machine;

[0042] 10. Ball mill;

[0043] 11. Grading device;

[0044] 12. Hydrocyclone sediment return channel. Detailed Implementation

[0045] To make the above-mentioned objectives, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to specific examples.

[0046] Unless otherwise specified, the raw materials or equipment used in the following embodiments are all commercially available products.

[0047] The primary crushing device used was a C100 jaw crusher;

[0048] The intermediate crushing device used is an HP300 cone crusher;

[0049] The high-pressure roller mill used is model HPGR1400-800, with a roller width of 800mm and a diameter of 1400mm;

[0050] The first screening device used was a 2.4m × 6.0m double-layer vibrating screen;

[0051] The X-ray sorting machine used is a COM Tertiary XRT sorting machine;

[0052] The ball mill used was a Φ4.0×6.0m overflow ball mill;

[0053] The grading device used was an FX350-GT×4 hydrocyclone.

[0054] Example 1

[0055] A low-grade ore integrated crushing, grinding, pre-selection, and waste disposal system with low energy consumption and high efficiency, such as... Figure 2As shown, it includes, in sequence: a first crushing mechanism, a second crushing mechanism, a high-pressure roller mill mechanism, a sorting mechanism, and a grinding mechanism. The raw ore is crushed by the first crushing mechanism and the second crushing mechanism to obtain medium crushed products. The medium crushed products are screened by the first screening device 4 and then enter the high-pressure roller mill mechanism to form a cake with internal microcracks. After being dispersed, the high-pressure roller mill products enter the screening mechanism. By adjusting the screen hole size, coarse, medium, and fine particles of material are obtained respectively.

[0056] In this process, the concentrate obtained by the ray separation of medium-sized materials is combined with the fine-sized materials and fed into the grinding unit. Through ball milling and cyclone classification in the grinding unit, a qualified product is finally obtained.

[0057] The first crushing mechanism includes a coarse crushing device 2, which can crush the raw ore into coarse ore with a particle size of 200~250mm; the second crushing mechanism includes a medium crushing device 3, which can further crush the coarse ore into medium ore with a particle size of 35~40mm.

[0058] Preferably, the first screening device 4 includes a buffer ore bin 401 and a quantitative feeder 402. The middlings obtained after two stages of crushing enter the buffer ore bin 401 through a pipeline, and are then transported to the quantitative feeder 402 through a pipeline. The quantitative feeder 402 stably feeds middlings of suitable particle size to the subsequent high-pressure roller mill mechanism.

[0059] The high-pressure roller mill mechanism includes a high-pressure roller mill 5, and the operating pressure of the high-pressure roller mill 5 is set to 5.5~5.8 N / mm. 2 After being subjected to high-pressure roller milling, a cake is formed, which is beneficial for subsequent sorting and grinding.

[0060] The sorting mechanism includes a second screening device 7 and a X-ray separator 9. The second screening device 7 and the X-ray separator 9 are connected by a high-pressure roller mill intermediate particle size product conveying channel 8. The material compacted by the high-pressure roller mill mechanism is dispersed and then fed into the second screening device 7. Different particle sizes are obtained by screening through a double-layer vibrating screen. Among them, the coarse particle size material is returned to the high-pressure roller mill 5 through the high-pressure roller mill coarse particle product conveying channel 6 for high-pressure roller milling again. The medium particle size material enters the X-ray separator 9 through the high-pressure roller mill intermediate particle size product conveying channel 8. A suitable sorting threshold is set, and the identified waste rock is blown out by a high-pressure air nozzle. The concentrate obtained by X-ray separation and the fine particle size material obtained by screening are combined and fed into the grinding mechanism.

[0061] The grinding mechanism includes a ball mill 10 and a classifying device 11, which together form a closed-circuit grinding system. The overflow fineness of the hydrocyclone in the classifying device 11 is controlled, and the material that meets the grade after mixing is sent to the flotation operation as the final qualified product. The underflow is returned to the ball mill 10 through the hydrocyclone underflow return channel 12.

[0062] Example 2

[0063] This embodiment processes a low-grade skarn-type tungsten ore, the properties of which are as follows:

[0064] The tungsten grade is 0.15%, and the ore is severely depleted. The gangue minerals are mainly calcite, quartz, and garnet. The useful mineral chalcopyrite is unevenly distributed in terms of grain size, with a uniform distribution of coarse and fine grains.

[0065] A low-consumption, high-efficiency integrated method for crushing, grinding, pre-selection, and waste disposal of low-grade ores, such as... Figure 1 As shown, the steps are as follows:

[0066] S1: The raw ore is fed from the raw ore bin to the coarse crushing device 2 (C100 jaw crusher) via the raw ore feeder 1, where it is crushed to 200mm. Then it is conveyed by belt to the medium crushing device 3 (HP300 cone crusher) for closed-circuit crushing, and the product particle size is controlled at 40mm.

[0067] S2: The medium-crushed product is stably fed into the high-pressure roller mill 5 (model HPGR 1400-800, roller width 800mm, diameter 1400mm) via a buffer ore bin and a quantitative feeder, with the operating pressure set at 5.5N / mm². 2 The roller gap is controlled at 15mm. After the material passes through the high-pressure roller mill, it forms a pressed cake with internal micro-cracks.

[0068] S3: After being broken up by the high-pressure roller mill, the product is fed into the second screening device 7 (2.4m×6.0m double-layer vibrating screen), with screen aperture sizes of 30mm and 10mm respectively; the screened product is:

[0069] +30mm particle size, accounting for 5% of the total, returns to the high-pressure roller mill 5 through the coarse product conveying channel 6 after the high-pressure roller mill to form a closed loop;

[0070] 10~30mm particle size, accounting for 45% of the total, is the target material for pre-selection and disposal;

[0071] -10mm particle size, accounting for 50% of the total, is directly conveyed to the pre-grinding mixing tank;

[0072] S4: The 10-30mm particle size material is conveyed to the X-ray separator 9 (COM Tertiary XRT separator) via the intermediate particle size product conveying channel 8 after passing through the high-pressure roller. The equipment uses X-ray transmission to identify tungsten ore (high density, large atomic number) from gangue, and sets an appropriate separation threshold (for 10-30mm particle size tungsten ore pre-discarding, the separation threshold needs to be determined through equipment calibration tests. Based on experience with similar ores, the equivalent atomic number (Zeff) threshold range is usually set between 22 and 28; in specific operation, the equipment software analyzes the grayscale histogram of the ore image to select the optimal threshold point, so that the tungsten metal recovery rate within this particle size is >90%, while achieving efficient waste disposal). High-pressure air is used to spray... The nozzle (high-pressure air parameters: the nozzle working pressure is usually set in the range of 5~7 bar, and is determined according to the particle size of 10~30mm and the ballistic trajectory. The airflow injection is controlled by a high-speed solenoid valve. The pulse width of a single injection is about 20~40ms to provide a precise and strong impact force to blow away the waste rock) blows out the identified waste rock; the waste rejection rate in this step is 70% (that is, discarding about 31.5% of the total raw ore waste rock); after the waste rejection, the copper grade of the concentrate of this particle size increases from 0.15% to 0.45%, and the metal recovery rate (within this particle size) reaches more than 90%;

[0073] S5: The concentrate obtained from X-ray separation is combined with the -10mm particle size material obtained from screening, reducing the total feed rate to 68.5% of the original ore. The combined material is fed into ball mill 10 (Φ4.0×6.0m overflow ball mill). Ball mill 10 and classifier 11 (FX350-GT×4 hydrocyclone group) form a closed-circuit grinding system. The overflow fineness of the hydrocyclones in classifier 11 is controlled to be -0.074mm, accounting for 70%. After mixing, the feed grade is 0.3%, which is sent to flotation as the final qualified product. The underflow is returned to ball mill 10 through hydrocyclone underflow return channel 12.

[0074] S6: Establish a database to record daily raw ore properties, high-pressure roller mill operating parameters (pressure, roller gap, throughput), X-ray separation waste rate and grade improvement, as well as final grinding fineness and flotation indicators; through data analysis, regularly optimize the pressure of the high-pressure roller mill and the sensitivity of X-ray separation to achieve dynamic optimal control.

[0075] Example 3

[0076] This embodiment deals with a skarn-type scheelite and cassiterite symbiotic ore. The raw ore has a low grade (WO3 0.25%, Sn 0.15%) and is brittle and easily turns into mud.

[0077] A method for integrated crushing, grinding, pre-selection, and waste disposal of low-grade ore with low consumption and high efficiency includes the following steps:

[0078] S1: The raw ore is fed from the raw ore bin to the coarse crushing device 2 (C100 jaw crusher) via a feeder, crushed to 250mm, and then conveyed by belt to the medium crushing device 3 (HP300 cone crusher), forming a closed-circuit crushing with the screening equipment, and the product particle size is controlled at 70mm.

[0079] S2: The medium-crushed product is stably fed into the high-pressure roller mill 5 via a buffer bin and a quantitative feeder, with the operating pressure set at 5.8 N / mm. 2 The roller gap is adaptively adjusted according to the feed particle size and pressure; after the material passes through the high-pressure roller mill, it forms a pressed cake with internal micro-cracks.

[0080] S3: After being broken up by the high-pressure roller mill, the product is fed into the second screening device 7 (2.4m×6.0m double-layer vibrating screen), with screen aperture sizes of 25mm and 10mm respectively; the screened product is:

[0081] +25mm particle size, returned to high-pressure roller mill 5 to form a closed circuit;

[0082] 10~25mm particle size is selected as the target material for pre-selection and disposal;

[0083] -10mm particle size is directly conveyed to the pre-grinding mixing tank;

[0084] S4: The 10~25mm particle size material is conveyed to the X-ray separator 9 through the intermediate particle size product conveying channel 8 after passing through the high-pressure roller; a suitable separation threshold is set, and the identified waste rock is blown out using high-pressure air nozzles; the waste rejection rate in this step is 28%; after waste rejection, the WO3 grade of the concentrate increases from 0.25% to 0.33%, and the WO3 recovery rate in this particle size is >92%;

[0085] S5: The X-ray separated concentrate and the -10mm particle size material obtained from screening are combined, with the total feed rate being 87.4% of the original ore. The combined material is fed into ball mill 7 (Φ4.0×6.0m overflow ball mill). The ball mill and the classifier 8 (FX350-GT×4 hydrocyclone group) form a closed-circuit grinding system. The overflow fineness of the hydrocyclones is controlled to be -0.074mm, accounting for 75%. The qualified product is sent to flotation.

[0086] S6: Establish a database to record key parameters and achieve dynamic optimization control through data analysis.

[0087] Results: Effectively avoids over-grinding of tungsten-tin minerals, removing a large amount of gangue at the coarse-grained stage, ensuring overall recovery rate, while significantly reducing energy consumption and cost. (It is recommended to provide the recovery rate measurement method and parameters; energy consumption parameters.) Recovery Rate Measurement

[0088] By systematically sampling and chemically analyzing the raw ore and various intermediate products (such as discarded waste rock, grinding feed material, final concentrate and tailings) (detecting WO3 and Sn grade), and measuring the weight of each product, the total recovery rate and operating recovery rate are calculated according to the metal balance.

[0089] Energy consumption indicators: By installing electricity meters, the power consumption of the high-pressure roller mill, ball mill, and auxiliary equipment (crusher, screening, sorting, pumps, etc.) is measured separately. The total power consumption per ton of raw ore for crushing and grinding is calculated based on the throughput (kWh / t). The process in Example 3 is expected to reduce power consumption per ton of ore by 20%~30% compared to the traditional process.

[0090] Comparative Example 1

[0091] The ore was a low-grade skarn-type tungsten ore from the same source as in Example 2, and the properties of the ore were the same as in Example 2.

[0092] The same ore is processed using the traditional "three-stage closed-circuit crushing + two-stage closed-circuit grinding" process:

[0093] Coarse crushing: The raw ore is crushed to 250mm by a jaw crusher;

[0094] Medium crushing: The coarse crushed product is crushed by a cone crusher;

[0095] Closed-circuit crushing and screening: The medium crushed product is fed into the fine crushing cone crusher, and its discharge and vibrating screen form a closed circuit. The material on the screen is returned to the fine crusher, and the particle size of the under-screen product is controlled at 15mm, which is used as grinding feed.

[0096] Coarse grinding and classification closed circuit: The fine crushed product is fed into the first-stage ball mill (Φ3.2×4.5m). The ground product is pumped into a set of hydrocyclones for classification. The underflow from the hydrocyclones is returned to the coarse grinding mill, and the overflow (60% of the particles are 0.3mm in size) enters the next stage.

[0097] Fine grinding and classification closed-loop: The overflow from the coarse grinding is fed into the second-stage ball mill (Φ3.6×6.0m), forming a closed loop with another set of hydrocyclones. The final overflow fineness of the hydrocyclones is controlled to be 0.074mm, accounting for 70%, before being sent to flotation.

[0098] The power consumption, steel consumption, over-grinding, flotation indicators, and economic benefits of the crushing and waste disposal methods used in Example 2 and Comparative Example 1 were measured and evaluated. The specific testing or evaluation methods are as follows:

[0099] Electricity consumption: Install electricity meters on the main power-consuming equipment (crushing, high-pressure roller mill, ball mill, pump, etc.) of the two systems respectively, count the total electricity consumption over a period of time, divide it by the total amount of raw ore processed in the corresponding period, and obtain the electricity consumption per ton of ore;

[0100] Steel consumption: The total weight of steel balls consumed by the mill within a certain period is calculated and divided by the total amount of ore fed into the mill during that period to obtain the steel consumption per ton of ore fed into the mill. The present invention reduces the amount of ore fed into the mill, and the high-pressure roller mill products are easy to grind, resulting in a significant reduction in steel consumption.

[0101] Over-grinding: Laser particle size analysis is performed on the final grinding product (cyclone overflow) entering flotation to calculate the weight percentage of -0.01mm fine particles;

[0102] Flotation parameters: Systematic sampling and chemical analysis of flotation feed, concentrate, and tailings are performed. The concentrate grade and recovery rate are calculated through metal balance. This invention improves the recovery rate due to the increased feed grade and improved particle size.

[0103] Economic benefits (reduction in processing cost per ton of ore): Comprehensive calculation: 1) Energy saving benefits (electricity saving of 4.5 kWh / t × electricity cost); 2) Steel saving benefits; 3) Waste disposal benefits (energy and steel consumption saved by grinding 31.5% less waste rock); 4) Quality improvement benefits (increased metal revenue due to a 5 percentage point increase in recovery rate); 5) Consumption reduction benefits (reduction in reagents due to reduced over-grinding).

[0104] The data for each indicator are shown in Table 1 below:

[0105] Table 1 Comparison of the grinding and polishing methods used in Example 2 and Comparative Example 1

[0106]

[0107] Comparing the data in Table 1 above, the following results can be obtained regarding the power consumption of the low-grade ore low-consumption and high-efficiency crushing, grinding, pre-selection, and waste disposal integrated treatment method of the present invention: total power consumption for crushing and grinding is reduced to 13.5 kWh / t, with a power saving rate of 25%; steel consumption: due to the reduction in feed amount and the improved grindability of the high-pressure roller mill product, steel ball consumption is reduced by 30%; over-grinding: the content of -0.01mm in the product is reduced by 8 percentage points; flotation indicators: due to the increase in feed grade and the improvement in particle size distribution, the recovery rate is increased by 5 percentage points under the condition of comparable tungsten concentrate grade; economic benefits: the feed grade is increased from 0.15% to 0.3%. Considering the power saving, steel saving, reduction in reagent consumption, and improvement in recovery rate, the cost per ton of raw ore is reduced by more than 35%, and the economic benefits are extremely significant.

Claims

1. A method for integrated low-grade ore crushing, grinding, pre-selection, and waste disposal with low consumption and high efficiency, characterized in that: The steps are as follows: S1: After the raw ore is crushed into coarse and medium crushing in sequence, medium crushed ore is obtained; S2: The medium crushed ore obtained in S1 is fed into a high-pressure roller mill (5). After being milled by the high-pressure roller mill, a cake with internal micro-cracks is formed. S3: The pressed cake obtained in S2 is broken up, and then the broken material is fed into the second screening device (7). Through screening, three different particle sizes of material are obtained: coarse, medium and fine. Among them, the coarse-grained material is returned to the high-pressure roller mill (5) to form a closed loop; Medium-sized materials are selected as the target materials for pre-selection and disposal. Fine-grained materials are directly conveyed to the pre-grinding mixing tank for subsequent grinding operations; S4: Feed medium-sized material into the X-ray separator (9), identify it through X-ray transmission, set the sorting threshold, and blow out the identified waste rock using a high-pressure air nozzle; S5: The concentrate obtained from the S4 ray separation is combined with the fine-grained material obtained from the S3 screening. The combined material is fed into the ball mill (10). After being ball-milled by the ball mill (10), it is transported to the classification device (11). The overflow product obtained after classification cyclone is sent to the flotation operation. The sediment obtained from the classification cyclone is returned to the ball mill (10).

2. The integrated treatment method for low-grade ore with low consumption, high efficiency, crushing, grinding, pre-selection, and waste disposal according to claim 1, characterized in that, In S1, after coarse and medium crushing, the particle size of the medium crushed ore is 40~70mm.

3. The integrated treatment method for low-grade ore with low consumption, high efficiency, crushing, grinding, pre-selection, and waste disposal according to claim 1, characterized in that, In step S2, the operating pressure of the high-pressure roller mill (5) is set to 5.5~5.8 N / mm. 2 The roll gap is 15mm.

4. The integrated treatment method for low-grade ore with low consumption, high efficiency, crushing, grinding, pre-selection, and waste disposal according to claim 1, characterized in that, In S3, the second screening device (7) is a double-layer vibrating screen with screen hole sizes of 30mm and 10mm respectively.

5. The integrated treatment method for low-grade ore with low consumption, high efficiency, crushing, grinding, pre-selection, and waste disposal according to claim 1, characterized in that, In S3, the coarse-grained material has a particle size of +30mm and accounts for 5% of the total; the medium-grained material has a particle size of 10~30mm and accounts for 45% of the total; and the fine-grained material has a particle size of -10mm and accounts for 50% of the total.

6. The integrated treatment method for low-grade ore with low consumption, high efficiency, crushing, grinding, pre-selection, and waste disposal according to claim 1, characterized in that, In S4, the airflow injection from the high-pressure air nozzle is controlled by a high-speed solenoid valve, and the pulse width of a single injection is approximately 20~40ms.

7. The integrated treatment method for low-grade ore with low consumption, high efficiency, crushing, grinding, pre-selection, and waste disposal according to claim 1, characterized in that, In S5, the overflow fineness of the hydrocyclone in the grading device (11) is -0.074mm, accounting for 70%, and the grade of the feed after mixing is 0.3%.

8. A dedicated system for the integrated treatment method of low-grade ore with low consumption, high efficiency, crushing, grinding, pre-selection, and waste disposal as described in any one of claims 1 to 7, characterized in that, It includes a first-stage crushing mechanism, a second-stage crushing mechanism, a high-pressure roller mill mechanism, a sorting mechanism, and a grinding mechanism connected in sequence; The first crushing mechanism includes a coarse crushing device (2), which crushes the raw ore into coarse ore with a particle size of 200-250 mm after it is transported into the coarse crushing device (2); the second crushing mechanism includes a medium crushing device (3), which can further crush the coarse ore into medium ore with a particle size of 40-70 mm.

9. The dedicated system according to claim 8, characterized in that, It also includes a first screening device (4) connected between the second crushing mechanism and the high-pressure roller mill mechanism. The first screening device (4) includes a buffer ore bin (401) and a quantitative feeder (402). The middlings obtained after the two crushing stages enter the buffer ore bin (401) through a pipeline, and are then transported to the quantitative feeder (402) through a pipeline. The quantitative feeder (402) stably feeds middlings of suitable particle size to the subsequent high-pressure roller mill mechanism.

10. The dedicated system according to claim 8, characterized in that, The sorting mechanism includes a second screening device (7) and a radiation separator (9). The second screening device (7) and the radiation separator (9) are connected by a high-pressure roller mill and an intermediate particle size product conveying channel (8). The material compacted by the high-pressure roller mill is then dispersed and fed into the second screening device (7), and different particle sizes are obtained by screening through a double-layer vibrating screen.

Images