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The mining operations at Oyu Tolgoi began with the establishment of the open-pit mine. The Southern Oyu deposit is mined using the open-pit method. Excavation of the mine pit began in August 2011, and the first ore was extracted in April 2012. The initial step in open-pit mining operations is drilling. Drilling machines create blast holes with an average depth of 16 meters, spaced approximately seven meters apart. During open-pit mining, benches and safety berms are created. The height of the benches is 15 meters, and the width of the safety berms is at least 5 meters. To ensure safety and prevent slope failure, the inclination of the slopes is precisely determined and fixed. The rock is broken using blasting for excavation and loading. After blasting, blasters inspect the blasted area to check for issues such as boreholes, cracks, and hazardous gases. If the conditions are safe, mining operations commence. Drones are used at the Oyu Tolgoi mine to conduct post-blast inspections safely. The broken rock is excavated and transported to haul trucks by electric and hydraulic excavators. The Oyu Tolgoi open-pit mine utilizes loaders with capacities ranging from 34 to 56 cubic meters and haul trucks with a payload capacity of 300 tons. The ore extracted from the mine is transported to the primary crusher using haul trucks. The ore is crushed in the primary crusher, reducing it to approximately the size of a fist. The ore is then conveyed to the primary ore stockpile of the concentrator plant via a surface conveyor belt that is 8.2 kilometers long. The mine team operates in three shifts and utilizes modern advanced technology in its operations. When the Oyu Tolgoi open-pit mine operates at full capacity, it supplies 100 to 110 thousand tons of ore per day to the concentrator plant, averaging approximately 40 million tons of ore per year. With the commencement of underground mining, Oyu Tolgoi will utilize both open-pit and underground mining simultaneously. Over 80% of Oyu Tolgoi's copper reserves are located deep underground. The development of underground infrastructure is a complex undertaking, involving numerous tasks and unique operational activities rarely seen elsewhere in the world. The planning for the Oyu Tolgoi underground mine began in 2005, based on many years of geological and geophysical research. Oyu Tolgoi Company is developing the Hugo Dummett ore body, located at a depth of at least 700 meters underground. This ore body, which is 2.5 kilometers long and 300 meters wide, will be mined using a fully mechanized method called block caving. Rio Tinto is one of the few companies in the world that has mastered block caving technology. Although block caving requires significant initial investment, it is estimated to be relatively safe and have low operating costs over the long term. Block caving involves cross-cuts along the ore body. Cross-cuts are made below the ore body at the production and upper draw levels, and blasting is used to break the rock, allowing the ore to collapse under its own weight. Draw bells are created between the draw and production levels by blasting, and the ore is drawn at the production level. Loaders at the production level transfer the drawn ore to the transport level via vertical shafts. The ventilation level is located below the production level and supplies fresh air to the workings. At the transport level, the ore is loaded into heavy-duty trucks and transported to the primary crusher, where it is crushed to the size of a fist. The primary crusher is as tall as a seven-story building. The crushed ore is transported by conveyor belt for 8.2 kilometers to reach the surface. This conveyor belt will connect with the existing surface conveyor belt. Ore extracted from both the underground and open-pit mines is transported via conveyor belts to the primary ore stockpile and processed at the Oyu Tolgoi concentrator plant. The daily continuous operation of the underground mine is supported by five vertical shafts, each approximately 1300 meters deep. Service shafts were constructed first and were used to transport personnel and materials into the mine during the early stages of underground mine construction. The ventilation shafts connect the underground mine to the surface and are the main support system. Workers enter the underground mine through these vertical shafts, and two-deck elevators with a capacity of 150 people descend to the depths in 2.5 minutes. All necessary equipment and materials for the underground mine are also transported via the production and service elevators. The two cages of the production elevator, which travel from underground to the surface, have a load capacity of 6 tons each. The transport system of the production shaft, connected to the crusher in the underground mine, will also serve as an additional exit for transporting ore to the surface. Dedicated ventilation shafts are designed to supply fresh air to the underground mine and exhaust stale air. Over 350 pieces of equipment, including drilling rigs, loaders, and haul trucks, operate daily in the underground mine. Portable shelters located near the work areas are designed to temporarily house workers in case of emergencies, providing them with oxygen and other necessities. All underground mine operations, including mining work, machinery, conveyor belts, ventilation, heating, and water supply, are monitored and controlled from the control room of the central administration and service center located on the surface. Health, safety, environment, mine planning, geotechnical engineering, shaft utilization, maintenance, logistics, and technical teams provide support to various departments, including drilling, construction, and access teams. These support teams are responsible for supplying all necessary parts, spare parts, materials, and equipment to ensure the efficient and continuous operation of the mine. At the peak of underground mine extraction and construction, over 1,000 workers will be employed per shift. Underground mine extraction will gradually increase, reaching a peak of 95,000 tons of ore extracted per day. The Oyu Tolgoi underground mine is an engineering marvel. This world-class mine is a guarantee of Oyu Tolgoi's future for many years to come. After extracting ore from the open-pit and underground mines, it is processed at the concentrator plant to separate copper, gold, and other valuable minerals from the host rock, producing copper concentrate as the final product for export. The concentrator plant crushes and grinds the extracted ore into very fine particles, consisting of mills and thickeners. Chemical reagents are added to alter the surface properties of the minerals to separate copper and gold-bearing minerals from the ore. The concentrate is then filtered and transported to the customer. Semi-autogenous grinding is used in the initial stage of processing. In the semi-autogenous grinding mill, water and large steel balls are added to grind the ore into fine particles, forming a slurry. The first stage of grinding occurs in the semi-autogenous grinding mill. Vibrating screens are used to screen the ground ore. Rocks larger than the screen openings, approximately the size of an egg, are returned to the cone crusher for further crushing. The larger particles from the ball mill are fed into a ball mill containing medium-sized steel balls, where they are ground to a coarse particle size. Classifiers separate fine-grained materials from coarse-grained materials. Coarse-grained materials are returned to the ball mill for grinding. The fine-grained slurry is transported via pipes by its own flow to the flotation section, where it passes through a series of flotation machines to separate copper and gold-bearing minerals and increase the copper content of the concentrate. In flotation, chemical reagents with special compositions are added to the slurry to enhance the recovery of copper and gold-bearing minerals. These chemicals help the copper and gold-bearing minerals attach to air bubbles, which then float to the surface, forming a froth. These frothy bubbles contain the valuable minerals. Cleaning and control flotation. The concentrate from cleaning flotation, with a copper content of 10-14%, is sent to secondary flotation to increase the copper content to approximately 14%. The remaining tailings are sent to control flotation, with the aim of recovering as much residual copper and gold-bearing minerals as possible into the concentrate. Bulk flotation. The final product has a copper content of 21.5-22%. In the bulk flotation stage, a similar concentration process occurs, bringing the copper content of the final product to the required level for export. Filtration and dewatering. The final concentrate is thickened and transferred to storage tanks. The concentrate is then filtered to remove excess water, resulting in a dry powder concentrate. Concentrate storage and packaging. The final product, copper concentrate powder, is prepared for packaging and transported to the concentrate storage facility. The final concentrate is packaged in two-ton bags and transported to the buyer by truck. Tailings management. After the concentrate is separated, the remaining material is called flotation tailings and is transferred to a tailings thickener to remove process water. Tailings storage facility. The thickened tailings are transported to the Oyu Tolgoi tailings storage facility, constructed according to international standards. 85% water recycling. The concentrator plant recycles 85% of the total water used in production, which is eight times more than originally planned in the plant's design. This makes Oyu Tolgoi one of the most productive plants in the world, using three times less water than other mining companies operating globally. Laboratory sampling and analysis are a crucial part of the concentrate production process and are performed at each stage of production. Automatic samplers continuously collect samples from the flows of the concentrator plant. The collected samples are sent to an internationally accredited laboratory located within the mine complex every four hours. Laboratory analysis is performed on samples from the open-pit mine, underground mine, and concentrator plant to determine the copper and other element content. Concentrate sample analysis and testing. When packaging the final product, the central geological laboratory takes representative samples from each batch and performs analysis of the elements in the export copper concentrate. This content is used to calculate the value of the product and the price paid by customers. Technical specialists and maintenance personnel are responsible for the safe and highly productive operation of the concentrator plant 24 hours a day.