Six major technological trends in future

With the development of industry and the increasing demand for mineral resources, both developed and developing countries take the possession of resources and the development of resources as strategic measures. Therefore, a large number of efficient, safe and low-cost mining technologies and methods have emerged in mining, which need to follow the pace of advanced technology and develop resources well.


Intelligence of Underground Mines


At present, underground mines in the world are pursuing high efficiency and safety, and the level of mechanization and automation is constantly improving.


Take Kiruna Iron Mine in Sweden as an example. Kiruna Iron Mine is famous for its high grade iron ore (iron content over 70%) and is one of the largest iron ore mines in the world. Its iron ore mining has a history of more than 70 years, and now it has changed from open-pit mining to underground mining. Intelligence of Kiruna Iron Mine is mainly due to the use of large-scale mechanical equipment, intelligent remote control system and modern management system. Highly automated and intelligent mining system and equipment are the key to ensure safe and efficient mining.


1) Development: Kiruna Iron Mine is jointly developed by shaft and ramp. There are three vertical shafts in the mine, which are used for ventilation, ore and waste rock lifting. The personnel, equipment and materials are mainly transported from the ramp by trackless equipment. The main lifting shaft is located in the lower wall of the orebody. Up to now, the mining face and the main transportation system have been moved down six times. At present, the main transportation level is 1 045 meters.


2) Borehole charging and blasting: Rock drilling trolley is used in roadway excavation, and the trolley is equipped with three-dimensional electronic measuring instrument, which can realize accurate drilling positioning. Stope drilling adopts SimbaW 469 remote control drilling jumbo produced by Atlas Company, Sweden, with a diameter of 150 mm and a maximum hole depth of 55 meters. The vehicle is positioned accurately by laser system, driverless, and can work continuously for 24 hours, with an annual ore caving volume of 3 million tons.


3) Long-distance loading and transportation and lifting of ore: Drilling, loading and lifting in Kiruna Iron Mine stope have been intellectualized and automated. Drilling trolleys and scrapers have been driverless.


The ore is loaded with Toro 2500E remote control scraper with a single efficiency of 500 tons per hour. There are two types of underground transportation system: belt transportation and automatic rail transportation. Rail automatic transportation generally consists of eight train of mine trucks. The mine truck is an automatic bottom unloading truck for continuous loading and unloading. The belt conveyor automatically transports ore from the crushing station to the metering device, and completes loading and unloading with the shaft skip. The whole process is controlled remotely.


4) Support and reinforcement technology of remote control concrete shotcrete technology: roadway support adopts shotcrete-bolt-net combined support, which is completed by remote control concrete shotcrete machine, and bolt and reinforcing bar net are installed by bolt trolley.


The application of leaching technology is more and more extensive


At present, leaching technology has been widely used to recover low-grade copper, gold ore and uranium ore. There are three types of leaching technology: in-situ leaching, heap leaching and in-situ crushing leaching.


In the United States, Canada, Australia and other countries, 0.15%-0.45% of low-grade copper ores are treated, more than 2% of copper oxide ores and 0.02%-0.1% of uranium ores are basically recovered by heap leaching and in-situ blasting leaching.


In the United States, for example, there are more than 20 mines in which copper is leached by in-situ blasting in the United States. For example, Mike Mine in Nevada and Zonia Copper Mine in Arizona produce more than 2.2 tons of copper per day. Bart Mine and Copper Queen Mine in Montana produce 10.9-14.97 tons of copper per day. The leached copper production in the United States accounts for more than 20% of the total output, gold production exceeds 30%, and uranium production mostly comes from leaching mining. Deep Mining Technology


With the continuous reduction of resources, the mining depth is getting deeper and deeper, and the mining depth is below 1000 meters, which brings many difficulties and problems that are not encountered in shallow mining. For example, with the increase of ground pressure and rock temperature, the difficulties of mine lifting, drainage, support and ventilation are also increasing.


At present, the mining depth of non-coal mines in China is generally not more than 700-800 meters, but in recent years, some deposits with a burial depth of about 1000 meters are being developed. Dongguashan copper deposit and Jinchuan No. 2 mining area belong to Tongling Nonferrous Metals Company.


Environmental Protection Work and Comprehensive Control of Mines


In foreign countries, especially in developed countries, comprehensive control measures are adopted for mine environment. There are strict technical standards for waste water, waste gas, waste residue, dust and noise discharged from mines. Many low-grade mines can not be constructed and put into operation because of the high cost of environmental protection.


At present, foreign countries also emphasize the establishment of waste-free mines and clean mines. The Walsman Coal Mine in Ruhr Industrial Zone in Germany is a successful example. The slurry of coal washery and coal ash burned after coal power generation and broken underground waste rock are added to cement by activation and stirring, and the PM pump is used to fill the empty area underground. The mine does not discharge any solid waste. The application of filling mining technology is becoming more and more extensive


Different filling materials are used according to different situations.


At present, filling should consider the following problems: first, to concentrate on the formation of practical and reliable systems. Effective filling technology should be studied and developed to effectively combine filling operation with mining operation cycle. Attention should be paid to the management of filling system.


The second is to study the technology that can optimize the existing system, the particle size distribution of high-quality filling material, the improved filling material preparation process in hydrocyclone and crushing, and the transportation technology used to optimize filling material such as pressure loss, wear and corrosion to optimize the overall design of filling system.


Third, strengthen filling