This article presents the approach and the results of estimating CH4 emission from surface mining in Quang Ninh province to develop its fugitive CH4 emission factors. The two largest active surface mines were selected named Nui Beo and Cao Son. By applying a direct measurement method with samples using a specific chamber, CH4 emission was collected and calculated for the whole mine. Results showed that CH4 emission varied from mine to mine both the total amount and its range of maximum and minimum. In detail, the total amount of CH4 emission from Cao Son is 19,032.87 m3with the range of 73.14% while these numbers of Nui Beo are 2,684.47 m3 and 76.38%, respectively. The CH4emission factors of surface mines then were estimated in the range of 0.0850 m3/ton and 0.0225 m3/ton respect to high emission level and low emission level. These values are close to the emission factors generated from Germany (0.015 - Lignite), Canada (0.088 - Lignite; 0.19 - Bituminous), South Africa (0.002÷0.064 - Bituminous). These emission factors are considered as scientific evidence to propose the national factors of CH4 emission of surface mining.

Журнал входит в Перечень изданий, рекомендованных Высшей аттестационной комиссией (ВАК) Журнал включен в международную реферативную базу данных и систему цитирования Scopus Адрес редакции, учредителя, издателя: 362021, РСО-Алания, г. Владикавказ, ул. Николаева, 44, Северо-Кавказский горнометаллургический институт (государственный технологический университет), редакция журнала «Устойчивое развитие горных территорий».

At present, according to the extraction plan in the year 2020 of Duong Huy Coal Company -Vinacomin, the mining is divided into three main zones: Central Zone extracts 06 faces; South Zoneextracts 2 faces and Northeast Zone extracts 2 faces. The designated total production of all zones is1,880,000 tons/year. To ensure the production of each mining zone, exhaust fan stations are installed atventilation roadway adits with a total of 05 main fan stations. However, in the near future, to ensure andmaintain production activities, the mine is being planned and operated using 03 main fan stations. Thecalculation results for the reasonable working mode of fan stations are as follows: for fan station FBCDZ-8-№32B at level +47 m, airflow is 167.69 m3/s and air pressure is 243.74 mm H2O; for fan station 2K56-№30 level +40 m, airflow is 123.37 m3/s and air pressure is 324.79 mm H2O; for fan station FBCDZ-8-№32B at level +44 m, airflow is 167.69 m3/s and air pressure is 354.99 mm H2O.

The current mining operation of mineral resources in QuangNinh province-Vietnam is increasingly complicated. Correspondingly, themanagement of the mine sites becomes more difficult. Records anddocuments of minerals and mine sites are archived in different forms.Database systems are stored dispersedly and insufficiently; in many caseslack accuracy, topicality and have not been linked to each othersystematically. These lead to many difficulties in accessing and extractinginformation for the implementation of management as well as for investorsand people with related interest. In this paper an advanced software hasbeen developed for the management of mineral resources and has beenapplied for Quang Ninh province. The software has improved thesupervision and administration of the mining operation in the province.

Reliable estimation of coal and rock mechanical properties at field scale is a prerequisite for numerical modelling of rock behaviours associated with longwall extraction. This paper describes a systematic approach from data collection, laboratory testing to rock mass properties derivation for simulation of longwall extraction, taking two longwall panels at Quang Ninh coalfield in Vietnam for example. The mechanical properties are verified through comparison with published data of the field, indicating close agreements. A simple numerical model is further developed to demonstrate the proper use of the obtained data. The simulation suggests that the ratio of model length to excavation length should be in the range of 2.5–5; uniaxial compressive strength, deformation modulus and tensile strength can be reduced by a factor of 5.0, 2.13 and 2.0, respectively; and a calibration and validation process must be performed to match in-situ longwall’s behaviours. The approach can be applied for derivation of reliable rock mass properties for numerical simulation of underground excavations.