Improving the capacity of excavation and transportation of open-pit mines

According to the plan, the output of open-pit coal mining in Quang Ninh accounts for 38-40% of the total coal output of the Vietnam National Coal - Mineral Industries Group (TKV). Accordingly, on average, each year, the mines will excavate and transport approximately 190 million ^m3 of rock and soil, with stripping coefficients ranging from 11.2-11.5 ^m3 /year. To meet production requirements, open-pit mines proactively invest in and optimize the excavation and transportation of rock and soil and coal; synchronize equipment and form suitable excavation and transportation complexes to improve mining capacity in increasingly difficult production conditions.

Transport Workshop 5 is the main unit of Deo Nai Coal Joint Stock Company - Vinacomin, currently managing and using 26 large-tonnage equipment. Including 2 HD 465-7R trucks with a payload of 55 tons, 9 CAT 777D trucks with a payload of 96 tons and 15 CAT 777E trucks with a payload of 96 tons. With such equipment capacity, the Company assigns the Workshop to transport 450,000 tons of coal and 4.9 million ^m3 of soil and rock each year.

"With the system of vehicles and equipment assigned to manage and operate, Transport Workshop 5 always excellently completes all production tasks. In particular, in the recent 2022 main seam lowering campaign, the workshop has implemented over 127% of the plan to transport soil, rock and coal assigned by the company" - Mr. Le Van Hung, Manager of Transport Workshop 5, Deo Nai Coal Joint Stock Company said.

On average, Deo Nai Coal is responsible for producing about 2.5 million tons of raw coal per year, excavating 21 million ^m3 of soil and rock. In the context of increasingly deep mining (currently approaching a depth of -250m, transmission height of 326m), the unit will need to invest in different types of transportation equipment to complete the assigned economic and technical indicators.

Loading and transport equipment operating at Deo Nai Coal Mine.

Mr. Thieu Dinh Giang, Deputy Director of Deo Nai Coal Joint Stock Company, said that in terms of means of transport alone, Deo Nai Coal is currently mobilizing 62 trucks with a capacity of 90-100 tons. Of which, the largest and most modern trucks in the mine are CAT 777E and 777D with about 43 vehicles. The rest are HD 785-7 and 787-8R. In addition to trucks with a capacity of 90-100 tons, Deo Nai Coal also uses 11 trucks with a capacity of 55-60 tons, suitable for operating in the bottom of the mine.

Not only Deo Nai Coal, open-pit coal mining units in Quang Ninh region also own modern loading and transport systems suitable for production locations. Loading and transport complexes are formed in the direction of synchronous capacity to save costs and improve mining capacity.

Cao Son Coal Joint Stock Company is currently managing and operating 361 pieces of equipment, operating on a mining area of more than 1,390 hectares. Of these, there are 53 excavators of various types, from EKG electric excavators to large capacity hydraulic backhoes such as PC1250, PC2000. Synchronized with these excavating equipment are 250 trucks transporting soil, rock and coal, with a load capacity of 35-100 tons. Depending on each production location, the Company will arrange excavating and transporting equipment linked and synchronized with each other.

"For example, the PC2000 excavator, with its hydraulically operated reverse bucket, has the largest capacity in the Vietnamese mining industry today. The PC2000's bucket has a capacity of ^12m3 , enough to serve the super-loaded trucks of 90 tons or more of the Cao Son mine. This machine is designed on a crawler system, can easily move and work at heights of 2-3m on the open-pit mine" - Mr. Nguyen Xuan Truong, Team Leader of PC17 Machine Team, Mining Site 1, Cao Son Coal Joint Stock Company - TKV assessed.

The synchronous combinations currently being implemented by open-pit mines in Quang Ninh are the synchronization of EKG electric excavators and hydraulic excavators with bucket capacities of ^3.5-6.7m3 with trucks with a load capacity of 36-58 tons. This combination is considered by the mines to be relatively suitable in current production conditions. The productivity of these types of excavators has increased by 101-122% compared to the standard. Excavators with large bucket capacities of ^8-12m3 are combined by the mines with trucks with a load capacity of 90-130 tons. These large-capacity equipment combinations, when operating together, also provide stable productivity, ensuring the standards issued by TKV.

Synchronized excavator - truck combination at Ha Tu coal mine.

Equipment synchronization is also carried out by mines on the basis of ensuring the mine's geometric parameters according to design, including width, transport route, floor height, floor slope angle, working bank slope angle, etc., thereby ensuring safety in production at open-pit mines.

Source