Ore crushing processing method

Abstract

The present invention belongs to the technical field of ore processing, and in particular relates to an ore crushing processing method. The method is an ore processing technology integrating blasting, crushing and grinding, and comprises the following steps: blasting is performed by controlling blasting parameters, the blasting parameters including hole spacing, row spacing, chassis resistance line, overdepth and blockage length, the hole spacing is 6.5m, the row spacing is 6.2m, the chassis resistance line is 7m, the overdepth is 1.2m, and the blockage length is 6m; a reasonable micro-difference interval time is determined, and blasting is performed hole by hole, and the micro-difference interval time is divided into an inter-hole delay and an inter-row delay, the inter-hole delay is 15-56ms, the inter-row delay is 32-102ms, the unit consumption of explosives is 0.63kg / m3, and the ore bulk rate after blasting is 1.9%. By controlling the blasting parameters and using less explosives per unit, the rate of large blocks blasted is greatly reduced, which greatly reduces the load on the crushing and grinding systems, increases the processing capacity of the crushing and grinding systems, and achieves better milling quality and particle size requirements.

Description

Technical Field

[0001] The invention belongs to the technical field of ore processing, and in particular relates to an ore crushing processing method. Background Art

[0002] As mining continues, ore becomes depleted, resources become increasingly depleted, and the economic cost of ore development becomes increasingly high, making development more and more difficult. Therefore, it is necessary to analyze the development costs of ore. Whether it is a metal mine or a non-metal mine, the development of ore requires crushing and grinding processes to achieve the fineness requirements for ore development and utilization. Furthermore, crushing and grinding systems are also the most energy-intensive operations in mine development. Therefore, reducing crushing and grinding energy consumption and improving crushing and grinding efficiency are the only way to achieve the development and progress of mines.

[0003] In current traditional mining development, mining processes and mineral processing (crushing, grinding, and separation) processes are considered separately, without further interdisciplinary research and connection between mining and mineral processing. This results in a lack of in-depth linkage between the functions of each process, high costs, and the failure to form integrated development of comprehensive energy consumption and technology for mining and mineral processing, thereby reducing the cost of mine development. This is especially true in the areas of blasting, crushing, and grinding, where mining and mineral processing are closely linked. Currently, only the link between crushing and grinding is widely used. Various technologies such as "more crushing, less grinding" and "crushing instead of grinding" have been applied to a relatively mature level and have achieved certain results. However, the crushing and grinding processes of various mines still have a series of problems, requiring the integration of crushing and grinding technologies.

[0004] Mining production energy consumption primarily occurs in the crushing and grinding stage. Improving crushing and grinding efficiency and quality is a key research area for operating mines. Existing technologies are limited to the application of crushing and grinding, resulting in high energy consumption and low efficiency. Therefore, the integration of "blasting, crushing, and grinding" technologies to effectively improve crushing and grinding efficiency and reduce energy consumption is a key issue currently under consideration. Summary of the Invention

[0005] In response to the technical problems existing in the background technology, the present invention provides an ore crushing and processing method, which innovatively integrates the engineering application of "blasting, crushing and grinding" to achieve high efficiency of crushing and grinding to maximize benefits.

[0006] To achieve the above objectives, the technical solution provided by the present invention is:

[0007] A method for crushing ore, which is an ore processing technology integrating blasting, crushing and grinding, comprises the following steps:

[0008] S1, blasting instead of fragmentation: blasting is performed by controlling blasting parameters, including hole spacing, row spacing, chassis resistance line, over-depth and blockage length. The hole spacing is 6.5m, the row spacing is 6.2m, the chassis resistance line is 7m, the over-depth is 1.2m, and the blockage length is 6m. The detonation method is designed to determine a reasonable micro-difference interval time. Millisecond tube detonators are used to detonate each hole. The micro-difference interval time is divided into inter-hole delay and inter-row delay. The inter-hole delay is 15-56ms, the inter-row delay is 32-102ms, and the unit consumption of explosives is 0.63kg / m 3 , the bulk rate of ore after blasting is 1.9%;

[0009] S2, more crushing and less grinding: the blasted ore raw materials are crushed in sequence by coarse crushing equipment, medium crushing equipment and fine crushing equipment, and sieved to obtain ore of qualified particle size. During the process, the crushing ratio of coarse crushing, medium crushing and fine crushing is adjusted to balance the equipment load rate;

[0010] S3, Selective Stage Grinding Process: Using multi-stage grinding method, the ore is ground in primary grinding equipment and regrinding equipment in sequence, and then screened to obtain ore that meets the flotation particle size.

[0011] Furthermore, in step S2, the crushing system is a 3500t / d series, and a three-stage and one closed-circuit crushing process is adopted, and finally a crushed ore product with a particle size of -14mm and 83% is obtained; the coarse crushing ratio is adjusted to 3.98, the medium crushing ratio is adjusted to 4.38, the fine crushing ratio is adjusted to 4.36, and the sieve size is selected to be 14*16mm.

[0012] Furthermore, in step S3, the ore grinding adopts a two-stage regrinding process. For copper-molybdenum ore, the diameter and ratio of the initial balls are calculated according to the semi-theoretical formula of the ball diameter, and then the balls are added for dynamic control; the diameter and ratio of the initial balls in the first-stage ball mill are: Φ90:Φ80:Φ60:Φ40=15:30:30:25, and the ratio of the additional balls is: Φ90:Φ80:Φ50=3:4:3; the diameter and ratio of the initial balls in the second-stage regrinding steel balls are: Φ50:Φ40:Φ30=1:2:1, and the ratio of the additional balls is: Φ50:Φ40=1:1; so that the optimal fineness of the regrinding of the copper-molybdenum mixed concentrate -0.074mm reaches 94.05%, and the optimal fineness of the regrinding of the copper-molybdenum separated molybdenum coarse concentrate -0.045mm reaches 93.30%.

[0013] Furthermore, the method for detecting the large block rate is that the raw materials after blasting arrive at the concentrator's heavy plate for detection, and X-ray particle size detection equipment is used to detect that the proportion of ore with a particle size greater than 1000mm is the large block rate.

[0014] The present invention has the following advantages and beneficial effects:

[0015] 1. In the present invention, by controlling the blasting parameters, less explosives are used, and the large block rate of blasting is greatly reduced. The large block rate is reduced from the original 4.5% to 1.9%, and the average explosive consumption is reduced from 0.706kg / m 3 Reduced to 0.63kg / m 3 Under the premise of reducing the large lump rate and preventing over-explosion, the load of the crushing system can be greatly reduced, so that the subsequent crushing system and grinding system can further increase the processing capacity while achieving better grinding quality and particle size requirements.

[0016] Second, the technical integration of "integrated crushing and grinding" of the present invention is not simply "replacing crushing with blasting", "more crushing and less grinding" or "selective grinding". Instead, it is based on the research of process mineralogy and crushing and grinding experiments, and is based on the characteristics of the ore itself to develop a complete set of integrated crushing and grinding systems. The previous process provides conditions for the next process to perform at its maximum capacity, effectively reducing the crushing and grinding load of the next process, and bringing each process to its full potential. Therefore, it is proposed here that crushing and grinding in mineral processing cannot be simply limited to these two stages. Crushing should be moved forward to the mining stage such as blasting, and grinding should realize the process characteristics of "selective grinding" at the back end. Only the innovative engineering application of the integrated "blasting, crushing and grinding" can greatly improve the efficiency and quality of crushing and grinding, so as to maximize the benefits of ore processing. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a statistical chart showing fluctuations in explosives consumption per unit from 2007 to 2015;

[0018] Figure 2 This is a comparison chart of the large block rate before and after the application of the "blasting instead of crushing" project;

[0019] Figure 3 This is a comparison chart of explosive consumption per unit before and after the engineering application of "blasting instead of fragmentation";

[0020] Figure 4 This is a comparison chart of rock collapse per meter of blasthole before and after the engineering application of "blasting instead of crushing";

[0021] Figure 5 This is a comparison chart of blasting costs before and after the engineering application of "blasting instead of crushing";

[0022] Figure 6 This is a comparison chart of daily processing capacity before and after the engineering application of the "more crushing, less grinding" technology;

[0023] Figure 7 This is a comparison chart of screening efficiency before and after the engineering application of the "more crushing, less grinding" technology;

[0024] Figure 8 This is a comparison chart of qualified particle sizes before and after the engineering application of the "more crushing, less grinding" technology;

[0025] Figure 9 This is a comparison chart of the fineness of the raw ore before and after the engineering application of the "selective grinding" technology;

[0026] Figure 10 This is a comparison chart of the re-grinding fineness of copper-molybdenum mixed coarse concentrate before and after the engineering application of the "selective grinding" technology;

[0027] Figure 11 This is a comparison chart of the re-grinding fineness of molybdenum coarse concentrate before and after the engineering application of the "selective grinding" technology. DETAILED DESCRIPTION

[0028] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments.

[0029] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention as claimed, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without creative effort shall fall within the scope of protection of the present invention.

[0030] Example

[0031] A method for crushing ore, which is an ore processing technology integrating blasting, crushing and grinding, comprises the following steps:

[0032] S1, blasting instead of fragmentation: blasting is performed by controlling blasting parameters, including hole spacing, row spacing, chassis resistance line, over-depth and blockage length. The hole spacing is 6.5m, the row spacing is 6.2m, the chassis resistance line is 7m, the over-depth is 1.2m, and the blockage length is 6m. The detonation method is designed to determine a reasonable micro-difference interval time. Millisecond tube detonators are used to detonate each hole. The micro-difference interval time is divided into inter-hole delay and inter-row delay. The inter-hole delay is 15-56ms, the inter-row delay is 32-102ms, and the unit consumption of explosives is 0.63kg / m 3 , the bulk rate of ore after blasting is 1.9%;

[0033] S2, more crushing and less grinding: the blasted ore raw materials are crushed in sequence by coarse crushing equipment, medium crushing equipment and fine crushing equipment, and sieved to obtain ore of qualified particle size. During the process, the crushing ratio of coarse crushing, medium crushing and fine crushing is adjusted to balance the equipment load rate;

[0034] S3, Selective Stage Grinding Process: Using multi-stage grinding method, the ore is ground in primary grinding equipment and regrinding equipment in sequence, and then screened to obtain ore that meets the flotation particle size.

[0035] Furthermore, in step S2, the crushing system is a 3500t / d series, which adopts a three-stage and closed-circuit crushing process. The three-stage and closed-circuit crushing process refers to crushing the raw ore through three crushing stages, and finally through a closed-circuit cycle crushing to crush the ore into the required particle size, and finally obtain a -14mm 83% crushed ore product; adjust the coarse crushing ratio to 3.98, adjust the medium crushing ratio to 4.38, adjust the fine crushing ratio to 4.36, and select the sieve size as 14*16mm.

[0036] Furthermore, in step S3, the ore grinding adopts a two-stage regrinding process. For copper-molybdenum ore, the diameter and ratio of the initial balls are calculated according to the semi-theoretical formula of the ball diameter, and then the balls are added for dynamic control; the diameter and ratio of the initial balls in the first-stage ball mill are: Φ90:Φ80:Φ60:Φ40=15:30:30:25, and the ratio of the additional balls is: Φ90:Φ80:Φ50=3:4:3; the diameter and ratio of the initial balls in the second-stage regrinding steel balls are: Φ50:Φ40:Φ30=1:2:1, and the ratio of the additional balls is: Φ50:Φ40=1:1; so that the optimal fineness of the regrinding of the copper-molybdenum mixed concentrate -0.074mm reaches 94.05%, and the optimal fineness of the regrinding of the copper-molybdenum separated molybdenum coarse concentrate -0.045mm reaches 93.30%.

[0037] Furthermore, the method for detecting the large block rate is that the raw materials after blasting arrive at the heavy plate of the concentrator for detection, and the X-ray particle size detection equipment is used. The proportion of ore with a particle size greater than 1000mm is the large block rate.

[0038] Example 1

[0039] From a structural perspective, some ores exhibit a brecciated structure, with metal minerals and gangue minerals easily breaking and dissociating, or forming rich intergrowths, making them fragile and easily dissociable. Euhedral and subhedral molybdenite, euhedral and subhedral magnetite, pyrite, and gangue minerals such as feldspar and quartz carbonate exhibit straight boundaries, making them easy to dissociate during crushing and grinding. These two types of ore are best suited to forming a well-defined dissociation surface during blasting and crushing, reducing the burden on the grinding stage.

[0040] Research on optimizing open-pit blasting parameters at Lala Luotang addresses the issues of large particle size and high bulk content in open-pit mining blasting. This maximizes crushing efficiency, improves crushing load, reduces equipment failure rate, and prevents equipment from being blocked by overly large ore, which can cause equipment downtime. Optimizing the chassis's anti-bottom line, increasing over-depth, and optimizing hole spacing ensures reasonable mesh parameter settings. Charges are strictly loaded according to requirements to reduce the length of hole blockage and thus reduce the amount of bulk in the upper blastholes. Repeated testing selects the optimal unit explosive consumption. A hole-by-hole initiation method utilizes high-strength, high-precision millisecond tube detonators to ensure that each hole within the blasting area is detonated individually in a specific spatial and temporal order. This allows the first hole to provide a new free surface for subsequent holes. According to blasting principles, the explosives remain in the rock for a long time, and a large proportion of the explosive energy is used to crush the ore, thereby reducing blasting vibration and fragmentation. Determining the appropriate microsecond interval is crucial for blasting quality. The micro-difference interval time was divided into two components: inter-hole delay and inter-row delay. Based on blasting theory and practical experience at the Lala Copper Mine, the inter-hole delay is 3-8 ms / m, and the inter-row delay is 8-15 ms / m. This translates to an inter-hole delay of 15-56 ms and an inter-row delay of 32-102 ms. Optimization of deep-hole bench blasting technology and parameters: Numerical simulation techniques were used to simulate and study the parameters of deep-hole bench blasting at the Lala Copper Mine, exploring optimal blasting parameters for deep-hole bench blasting. Based on computer simulation results and relevant theory, repeated field tests were conducted and analyzed, leading to the gradual optimization of deep-hole bench blasting technology and parameters, improving blasting effectiveness and reducing production costs. By optimizing the hole pattern and reducing the number of over-depth holes, the penetration footage and explosives consumption per unit were effectively reduced. This improved the charge centering, reduced the rate of large upper lumps, and improved blasting quality, laying a solid foundation for subsequent work.

[0041] 1. Situation before the engineering application of “blasting instead of crushing” technology

[0042] 1. Explosive consumption per unit

[0043] Reference Figure 1 It can be seen that the explosive consumption per unit fluctuated greatly from 2007 to 2015, with the highest reaching 0.713 kg / m 3 , the minimum is 0.689kg / m 3 .

[0044] 2. Blasting parameters for different segments

[0045] Table 1: Blasting parameters in different mining sections over the years

[0046]

[0047] Table 1 lists the blasting parameters for the ore supply block section, stripping block section, and stone removal section from 2007 to 2015. These blasting parameters have remained unchanged for many years. After analysis and verification, it was found that these were not the optimal parameters. In addition, the average unit consumption of explosives reached 0.706 kg / m 3 , after testing these blasted ores, the large block rate also reached 4.5%.

[0048] 2. Engineering Application Results of “Explosion Instead of Crushing” Technology

[0049] After dozens of field tests from 2016 to 2017, the blasting parameters were repeatedly adjusted and optimized, the blasting effect was significantly improved, the blasting quality met the expected requirements, and the unit consumption of explosives was effectively reduced, and the rate of large blocks was significantly reduced, thus achieving the goal of "replacing fragmentation with blasting".

[0050] 1. Optimization and adjustment test comparison

[0051] Table 2: Blasting parameter adjustment and optimization test data

[0052] Parameter name Blasting parameters before the test Test parameters Adjust optimized parameters <![CDATA[Unit consumption adjustment of explosive / kg / m 3 > 0.68 0.60 0.63 Hole distance / m 6.5 / 6 7 / 6.5 6.5 Row spacing / m 6 6 / 6.5 6.2 Chassis resistance line / m 7 / 6.5 6.5 7 Extra deep / m 1.5 1.0 1.2 Blockage length / m 6.3 5.8 6

[0053] Explosive consumption per unit: 0.6kg / m 3 Too low a large block rate will inevitably increase the cost of secondary blasting; the unit consumption of explosives is 0.68kg / m 3 Too high will cause over-explosion, and waste rock and ore will be difficult to separate, which is a waste; the unit consumption of explosives is 0.63kg / m 3 The block size is relatively reasonable and can meet production needs.

[0054] 2. Comparison of large-block rates before and after the engineering application of "blasting instead of crushing"

[0055] The large block rate from 2010 to 2015 before the application of the “blasting instead of crushing” engineering method is compared with that from 2017 to 2022 after the application. Figure 2 .from Figure 2 It can be seen that the large block rate is significantly reduced before and after the engineering practice of "blasting instead of crushing" technology, from the original 4.5% to 1.9%, and the overall particle size is also significantly reduced, which provides better particle size requirements for crushing.

[0056] 3. Comparison of explosives consumption before and after the engineering application of "blasting instead of fragmentation"

[0057] The consumption of explosives per unit from 2010 to 2015 before the application of “blasting instead of fragmentation” and from 2017 to 2022 after the application are compared. Figure 3 .from Figure 3 It can be seen that after the engineering application of the “blasting instead of crushing” technology, the average unit consumption of explosives was reduced to 0.628kg / m while ensuring the reduction of large block rate and the overall ore particle size.3 .

[0058] 4. Comparison of rock collapse per meter of blasthole before and after the application of “blasting instead of crushing” engineering

[0059] The rock fall per meter of blasthole from 2010 to 2015 before the application of “blasting instead of crushing” was compared with that from 2017 to 2022 after the application. Figure 4 . Figure 4 The comparison shows that after the application of "blasting instead of crushing" engineering, the average rock collapse per meter of blasthole has increased from 28.29m 3 / m increased to 33.72m 3 / m, greatly increasing the effective blasting volume.

[0060] 5. Comparison of blasting costs before and after the engineering application of "blasting instead of crushing"

[0061] The blasting costs from 2010 to 2015 before the application of “blasting instead of crushing” and from 2017 to 2022 after the application are compared. Figure 5 . Figure 5 It can be seen that after the engineering application of "blasting instead of crushing", the average unit cost increased from 6.33 yuan / m 3 Reduced to 5.63 yuan / m 3 .

[0062] Example 2

[0063] The original crushing process of Lala Copper Mine was divided into two series: 1500t / d and 3500t / d. The 1500t / d series adopted a three-stage, one-closed-circuit traditional crushing process, and ultimately obtained a crushed ore product with 80% of its particle size being -18mm. The 3500t / d series also adopted a three-stage, one-closed-circuit crushing process, and ultimately obtained a crushed ore product with 83% of its particle size being -14mm. The crushed ore products could not meet the feeding requirements for grinding, nor could they reach the processing capacity of 5000t / d, but could only reach 4000t / d. Moreover, the crushing and grinding effect was very poor, and the fineness did not meet the requirements.

[0064] In order to solve the above technical problems, based on the "explosion instead of crushing" embodiment 1, the integrated optimization of crushing and grinding is considered.

[0065] First, adjust the medium and fine crushing ratio and balance the medium and fine crushing load rate; adjust the screen hole size of the vibrating screen and replace the screen surface material with wear-resistant polyurethane screen to improve the screening efficiency of the vibrating screen to achieve process stability.

[0066] Under the premise of controlling the blasting parameters in Example 1, the 1500t / d crushing system was deactivated, and only the 3500t / d crushing system was used to achieve the full-load production of 5000t / d, meeting the standard. All indicators tended to be stable, and the production system was unimpeded. This also broke the design concept of the crushing process of approximately 16 hours, achieving stable and reliable operation of approximately 20 hours, improving the equipment operation rate, reducing equipment idling, and effectively saving energy consumption. It reached the domestic advanced level and truly achieved the goal of "more crushing and less grinding".

[0067] 1. Comparison of parameter adjustments before and after engineering application of the “more crushing, less grinding” technology

[0068] Table 3: Comparison of process operating parameters of ore crushing system

[0069] project Before application After application Coarse crushing ratio 4.72 3.98 Medium crushing ratio 3.00 4.38 Fine crushing ratio 5.42 4.36 Sieve hole size / mm 16×18 14×16

[0070] 2. Achievements in the Engineering Application of “More Crushing, Less Grinding” Technology

[0071] A data comparison was conducted 12 months before and after the application of the "more crushing, less grinding" technology, comparing the crushing capacity, screening efficiency, product quality, equipment operating rate and equipment operating time. The technical goal of "more crushing, less grinding" was achieved, and the materials were prepared for grinding.

[0072] from Figure 6 It can be seen that after the engineering application of the "more crushing and less grinding" technology, the average daily processing capacity has increased from 4081t / d of the original two crushing systems (1500t / d and 3500t / d) to 5144t / d of one crushing system (3500t / d), achieving the full production capacity and standard of crushing.

[0073] from Figure 7 It can be seen that after the engineering application of the "more crushing and less grinding" technology, the average screening efficiency increased from 65.05% to 84.85%, the screening efficiency was significantly improved, and the circulating load of crushing and screening was effectively reduced.

[0074] from Figure 8 It can be seen that after the engineering application of the "more crushing and less grinding" technology, the average qualified particle size content of -12mm increased from 76.75% to 94.16%, and the qualified particle size increased significantly, truly achieving the goal of "more crushing and less grinding" and providing a good guarantee for grinding.

[0075] Example 3

[0076] Grindability tests, grinding product particle size analysis, mineral particle size analysis, mineral dissociation characteristics, mineral intergrowth relationships, mineral inclusion relationships, and mineral specific surface area analysis indicate that the Lala copper ore has a complex mineral composition, uneven distribution of coarse and fine particles, chaotic mineral intergrowth and inclusion, and difficulty in separating individual minerals. The gangue minerals are complex, with an intermingling of easily grinded and difficult-to-grind minerals. This presents significant challenges for the beneficiation of the Lala multi-metallic copper ore, requiring both fineness requirements to be met to fully separate useful minerals and overgrinding to prevent loss of useful minerals due to unrecoverable losses. Therefore, while maximizing the "blasting instead of crushing" and "more crushing, less grinding" techniques employed in the previous two embodiments, ensuring both throughput requirements and optimal milling quality and particle size are achieved, grinding is crucial. Grinding classification must ensure that easily grinded minerals are not over-grinded, that difficult-to-grind intergrowths are fully separated, and that useful minerals are optimally separated. This requires the ultimate engineering application of "selective grinding" technology, which is the key to integrated crushing and grinding.

[0077] According to the grinding fineness test, the best recovery index for copper and molybdenum is a grinding fineness of -0.074mm reaching 60% to 65%. The processing capacity of the 5000t / d system basically meets the design requirements, but the grinding fineness (i.e., the fineness of the selected ore) is only 50%. From the specific production situation, the crushing and grinding processing capacity is basically at full capacity, but the optimal fineness for flotation has not been achieved.

[0078] After sufficient feasibility analysis, a segmented (multi-stage) regrinding process was adopted to improve the grinding fineness. That is, an MQY2700×4500 overflow ball mill and a Φ500 cyclone were added to form a closed-circuit classification as the second-stage grinding. After this solution was applied in production, it can effectively improve the selection fineness (-200 mesh content is 65%) while meeting the processing capacity of 5000t / d. It can also improve the flotation and subsequent operating environment, so that various technical indicators can be greatly improved.

[0079] In actual production, when the optimal fineness is 60% to 63%, the processing capacity can be further improved; precise dynamic ball loading and replenishment technology is applied. The diameter and proportion of the initial ball are accurately calculated based on the semi-theoretical formula of ball diameter, and then the daily dynamic adjustment of the additional balls is carried out in combination with the on-site conditions. According to the precise theoretical addition of ball loading, statistical calculations are performed, and the diameter and proportion of the initial ball of the first-stage ball mill are adjusted to: Φ90:Φ80:Φ60:Φ40=15:30:30:25, and the proportion of additional balls is: Φ90:Φ80:Φ50=3:4:3; the diameter and proportion of the initial ball of the second-stage regrinding steel ball are: Φ50:Φ40:Φ30=1:2:1, and the proportion of additional balls is: Φ50:Φ40=1:1. When the particle size of the ore entering the mill and the particle size composition of the grinding product change, the diameter of the steel ball is also dynamically adjusted accordingly; the coarse and concentrate stages The stage grinding and classification processes have been improved and optimized, and the regrinding equipment has been innovated. The cyclone classification parameters have been adjusted. The optimal regrinding fineness of the copper-molybdenum mixed concentrate is -0.074mm, reaching 94.05%. The optimal regrinding fineness of the copper-molybdenum separated molybdenum coarse concentrate is -0.045mm, reaching 93.30%. In addition, the process flow and operating parameters can be dynamically adjusted according to the changes in ore properties and the requirements of concentrate quality, making the process flow very flexible, achieving the optimal state of regrinding effect and classification efficiency, and thus achieving the goals of maximizing benefits and minimizing costs.

[0080] 1. Comparison of ore fineness

[0081] The original one-stage closed-circuit grinding and classification process was transformed into a two-stage closed-circuit grinding and classification process. The precise dynamic ball loading technology was innovatively applied on site. Under the premise of ensuring that the processing volume reached the production capacity and standards, the fineness of the raw ore was significantly improved, reaching the optimal fineness range for copper-molybdenum mixed flotation.

[0082] like Figure 9 As shown in the figure, the comparison was made 12 months before and after the engineering application. Figure 9 By comparison, it can be seen that after the engineering application of the "selective grinding" technology, the average fineness of the raw ore entering the selection process increased from the original 53.22% to 63.56%, reaching the optimal fineness requirement for copper-molybdenum mixed flotation.

[0083] 2. Comparison of regrinding fineness of copper-molybdenum mixed coarse concentrate

[0084] from Figure 10 By comparison, it can be seen that after the engineering application of the "selective grinding" technology, the average fineness of the copper-molybdenum mixed coarse concentrate increased from the original 88.12% to 94.05%, meeting the optimal fineness requirements for the selection of copper-molybdenum mixed coarse concentrate.

[0085] 3. Comparison of regrinding fineness of molybdenum coarse concentrate

[0086] from Figure 11By comparison, it can be seen that after the engineering application of the "selective grinding" technology, the average fineness of the molybdenum coarse concentrate increased from the original 88.12% to 94.05%, meeting the optimal fineness requirements for the selection of molybdenum coarse concentrate.

[0087] In the present invention, the technical integration of "integrated crushing and grinding" is not a simple "replacing crushing with blasting", "more crushing and less grinding", or "selective grinding". Instead, it is based on the research of process mineralogy and experimental research on crushing and grinding, and based on the characteristics of the ore itself, a complete set of integrated crushing and grinding systems has been developed. The previous process provides conditions for the next process to do its best, effectively reducing the crushing and grinding load of the next process, and bringing each process to its full potential. Therefore, it is proposed here that the crushing and grinding in mineral processing cannot be simply limited to these two stages of operation. The crushing should be moved forward to the mining stage such as blasting, and the grinding should realize the process characteristics of "selective grinding" at the back end. The innovative engineering application of the integrated "blasting, crushing, and grinding" has achieved the goal. Only such an integrated technology of "integrated crushing and grinding" that crosses professional fields and process boundaries can achieve high efficiency of crushing and grinding to maximize benefits.

[0088] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that various modifications and variations of the present invention are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A method for crushing ore, characterized in that: The method is an ore processing technology that integrates blasting, crushing and grinding, and includes the following steps: S1, using explosion instead of fragmentation: Blasting is performed by controlling blasting parameters, including hole spacing, row spacing, chassis resistance line, over-depth and blockage length. The hole spacing is 6.5m, the row spacing is 6.2m, the chassis resistance line is 7m, the over-depth is 1.2m, and the blockage length is 6m. The detonation method is designed to determine a reasonable micro-difference interval time. Millisecond tube detonators are used to detonate each hole, and the micro-difference interval time is divided into inter-hole delay and inter-row delay. The inter-hole delay is 15-56 ms, the inter-row delay is 32-102 ms, and the unit consumption of explosives is 0.63kg / m 3 The large block rate of ore after blasting is 1.9%; the method for detecting the large block rate is that the raw materials after blasting arrive at the concentrator's heavy plate for detection, and the X-ray particle size detection equipment is used to detect the proportion of ore with a particle size greater than 1000mm, which is the large block rate; S2, more crushing and less grinding: the blasted ore raw materials are crushed in sequence by coarse crushing equipment, medium crushing equipment and fine crushing equipment, and sieved to obtain ore of qualified particle size. During the process, the crushing ratio of coarse crushing, medium crushing and fine crushing is adjusted to balance the equipment load rate; S3, Selective Stage Grinding Process: Using a multi-stage grinding method, the ore is ground in the primary grinding equipment and the regrinding equipment in sequence, and then screened to obtain the ore that meets the flotation particle size; In step S2, the crushing system is a 3500t / d series, which adopts a three-stage and one-closed-circuit crushing process, and finally obtains a crushed ore product with a particle size of -14mm and 83%. The coarse crushing ratio is adjusted to 3.98, the medium crushing ratio is adjusted to 4.38, the fine crushing ratio is adjusted to 4.36, and the sieve size is selected to be 14*16mm.

2. The ore crushing method according to claim 1, characterized in that: In step S3, the ore grinding adopts a two-stage regrinding process. For copper-molybdenum ore, the diameter and ratio of the initial balls are calculated according to the semi-theoretical formula of ball diameter, and then the balls are added for dynamic control; the diameter and ratio of the initial balls in the first-stage ball mill are: Φ90:Φ80:Φ60:Φ40=15:30:30:25, and the ratio of the additional balls is: Φ90:Φ80:Φ50=3:4:3; the diameter and ratio of the initial balls in the second-stage regrinding are: Φ50:Φ40:Φ30=1:2:1, and the ratio of the additional balls is: Φ50:Φ40=1:1; so that the optimal fineness of the regrinding of the copper-molybdenum mixed concentrate -0.074mm reaches 94.05%, and the optimal fineness of the regrinding of the copper-molybdenum separated molybdenum coarse concentrate -0.045mm reaches 93.30%.

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