0 Preface
Zambia Chambishi copper mine under the China Nonferrous Metals Group Africa Mining Co., Ltd., is one of the world's largest typical sedimentary deposits, located in the central region of Zambia, pre mainly open-pit mining, with the gradual depletion of mineral resources, starting from the open-air 1975 Transfer to underground mining, the mine has now been transferred to deep mining [1]. The main ore body is jointly developed by shaft and ramp. The main chute has a diameter of 2.4m and a full height of 400m. It is constructed by a rig drilling machine . Therefore, the main chute is a waterfall structure. Although the previous plugging situation occurred from time to time, the main mine The ore rock has good fluidity, and it is not easy to be muddy or sticky when it is in contact with water. Therefore, most of the plugging is caused by large blocks. It can be easily cleared by using traditional bamboo rafts and appropriate bare explosives. [2 ].
After the western ore body reached its production in 2012, in order to solve the problems of high cost and low efficiency of the ore transportation of the ore in the mining area, it was decided to make full use of the advantage of the main ore body shaft to enhance the surplus capacity, and the main ore body shaft was used to upgrade the ore. Starting from 2014, nearly half of the ore of the western ore body will be transported to the main chute for transportation through the docking high patio of the main and western ore bodies. However, due to the particularity of the ore body rock, after the docking project operation, the frequency of plugging the well in the 800-900m section of the main chute is increased, and the processing time is also obviously lengthened. The traditional chute blocking treatment method is not only a safety hazard, but also the processing time. Longer, severely restricts the lifting capacity of the shaft. According to the ore conditions of the main and western ore bodies, the method of seeking safe and efficient dredging of the wells has become an urgent problem [3].
1 mineral rock properties
The main lithological Chambishi occurrence of argillaceous quartzite, feldspar, quartz rock, gravel, argillite and mineralization argillaceous slate, wherein the main ore bodies located in argillite, The argillaceous slate can be divided into three parts: mineralized shale shale, argillaceous slate ore body and schist. According to the on-site blasting situation, the ore is evenly ruptured after blasting, and it is not easy to muddy when it is in contact with water, so the fluidity is better in the shovel. The Chambishixi ore body is mainly distributed in mineralized slate. Due to the influence of geological conditions, the lithology is poor, joints and fissures are relatively developed. Due to the influence of sand layer and conglomerate layer, the stability of the upper and lower plates of the ore body is better. Poor, the RQD value of the rock in this area obtained by on-site coring is very low, 50%-60%. There is a certain degree of oxidized ore zone in the upper and lower plates of the ore body. Due to oxidation, the ore is easily muddy. And produce a certain "sticky", which is extremely unfavorable for mining.
2 chute blockage and type
When the main chute of Chambishi only serves the main ore body ore, there are occasional blockages, but it mainly occurs in the wellhead of 800-900m, and most of them are caused by large blockage. Therefore, the traditional chute blocking treatment method is adopted. Can handle card jams easily [4]. Since the transfer of the ore body ore to the main chute, the probability of blockage has increased significantly and the processing time has been greatly extended (see Table 1).
Through on-the-spot investigation, the clogging position and the number of clogging times of the chute are counted according to the clogging position of the chute, which can be divided into two types: the internal blockage of the wellbore and the sluice at the bottom of the chute. The blockage inside the wellbore can be divided into the downhole. Partial blockage and blockage of the upper part of the chute. According to the blockage of the chute from 2013 to 2015, the upper part of the wellbore was blocked 7 times in the main chute, the lower part of the wellbore was blocked 17 times and the bottom of the chute was blocked 49 times. The blockage of the chute is caused by a variety of factors, and it is classified according to the cause of blockage. It is mainly divided into three types of blockage: silt muddy arching, blasting block jam and powder ore arching and large block combination. Through investigation and analysis, after the western ore body ore is discharged into the main chute, the blockage caused by the silt of the powder ore is 19 times, and the number of blockages caused by the blasting block is 9 times. The resulting blockage was 25 times. In the process of mine drainage, due to the different degrees of ore muddying, the difference in the control of the ore discharge speed may cause the mineral powder to accumulate together, so that the net section of the slip well is reduced, and at the same time, due to the influence of large blocks, the balance of accumulation is easy to form. arch.
3 medium-deep hole blasting treatment of blocked chute
When the main chute only undertakes the ore transport of the main ore body, the traditional method can easily dredge the chute. After the ore of the western ore body is mixed into the main chute, the clogging is frequent due to the muddy and sticky nature of the ore, and it is difficult to handle by conventional methods, the treatment time is longer, and the safety is not up to the requirement. Therefore, the infrared observation combined with the deep hole blasting treatment measures [4-7] is proposed, which not only speeds up the processing time, but also improves the safety of the treatment. The layout of the main chute blockage treatment construction is shown in Figure 1.
The most recent medium-deep hole blasting method is as follows:
(1) First, an infrared device is used to measure the height of the blockage position, and the infrared instrument is bound to the bamboo pole, and then the bamboo pole is inserted into the lower mouth of the slide along the observation path, and the position height of the blockage is accurately measured by infrared rays. The height of the blockage measured at the last blockage was 40m. Due to the strong interference of infrared rays against environmental unfavorable factors, it is convenient to measure the height of the blockage and determine the specific position of the blockage.
(2) Secondly, the medium-deep hole blasting design is carried out according to the original parameters of the chute and the measured data (see Figure 1). The construction parameters of the deep-deep hole are shown in Table 2. The hole azimuth angle is 298°8'5′′ and the hole diameter is 150cm. .
A total of 4 holes are arranged in the middle and deep holes, and the T150 deep hole drilling machine is used for construction. After each hole is constructed, it is flushed by the high pressure water of the drilling machine, and the blockage body is continuously dropped downward. After the construction and flushing of 4 holes, part of the blockage has been dropped, and the height is determined to be 45m by the infrared device, and then the blockage of the main chute is smoothly unblocked by reasonable charging and millisecond detonator segmentation. From the punching to the blasting to clear the main chute, it took a total of 1d time. According to Table 1, it can be seen that the processing time of the chute block can be shortened by more than 2d after the main chute is blocked by the deep hole blasting in 2015.
4 chute blockage prevention measures
By analyzing the cause of blockage of the main chute in the Chambishi copper mine, in order to prevent frequent blockage of the chute, a strict production management system for chute should be established, following the principle of “prevention firstâ€. The main production management systems are as follows:
(1) Select reasonable rock drilling and blasting parameters [8-10]. For the case that the western ore body rock has good blastability, the blasthole parameters and charge structure should be optimized to reduce the amount of fine ore after blasting.
(2) Reduce the storage time of the main chute and make the linkage up and down. When the ore is upgraded, the ore of the western ore body is poured into the main chute, and the matching of the main ore body and the western ore body is improved.
(3) Reduce the number of times of ore transfer, and the ore will be transferred to the mine after blasting. If the ore is stored in the transfer chamber, it will increase the secondary reversal, thereby increasing the amount of fine ore produced.
5 Conclusion
(1) The change of ore properties, the increase of large ore, and the long time of storage of ore directly lead to the blockage of the main ore.
(2) For the main chute blockage serving only the main ore body, it can be safely and efficiently treated only by the conventional method.
(3) For the blockage caused by the ore body ore entering the main chute, the infrared ray is used to accurately measure the blockage height, and then the deep hole blasting is used to treat the plugging chute. It is not only safe, but also can shorten the treatment time by more than 2d, according to the advance 2d. With normal production, the economic benefit can be about 180,000 US dollars.
(4) Strengthen the optimization of rock drilling and blasting parameters, reduce the number of ore transfer, and formulate and implement the production management system for the well, which can effectively prevent the blockage of the well.
references:
[1] Zhu Zhibin, Zhang Zhengping, Zhang Binzhou, et al. Analysis and treatment of chute blockage [J]. China Mining Engineering, 2007, 36(2): 26-27.
[2] He Biaoqing. Analysis and prevention [J] Mt. Zijinshan Gold Mine reason chute blockage. Gold, 2005, 26 (6): 26-27.
[3] Shi Fawu, Liu Xiaohui, Wang Yuming, et al. Application of deep hole blasting into well in Qianbishi copper mine [J]. Modern Mining, 2014 (2): 121-124.
[4] Miao Ding, Li Weiqiang, Li Shuowei. Application of medium and deep hole blasting suspension treatment in Jinyuan Company [J]. Mining Technology, 2016, 16 (01): 81-82.
[5] Liu Daoren. Application of medium deep hole blasting in patio excavation [J]. China Mining Engineering, 2011, 40(4): 36-38.
[6] Zhang Qi, Li Jiaqing. Application of deep hole blasting into wells in Zhaokou Mine [J]. Shandong Metallurgy, 2009, 31 (4): 38-39.
[7] Yan Deming. Deep hole section blasting method for drilling wells in goaf filling wells [J]. Journal of Central South Institute of Mining and Metallurgy, 1993, 24 (5): 590-595.
[8] Li Yubo, Li Yangang, Han Quan, et al. Application of medium and deep hole segmental stage filling mining in Daliang Mining [J]. Mining Technology, 2016, 16 (03): 5-7.
[9] Zhiwei, Luo Jia, Wang Lihong. Experimental Study [J] dragon lead zinc ore hole blasting parameters. Mining Technology, 2016, 16 (03): 83-86.
[10] Deng Fei, Hu Longfei, Liu Xiaojun, et al. Experimental study on optimization of deep hole blasting parameters in Qianjiaping vanadium mine [J]. Mining Research and Development, 2014, 34(03): 118-122.
Source: Mining Technology: 2016.16(5);
Copyright:
Silicone Baby Teether,Silicone Bead Baby Teether,Silicone Mushroom Baby Teether,Soft Silicone Baby Teether
Hubei Daxin Electronic Technology Co., LTD , https://www.aiwellgroup.com