UNDERGROUND MINING CONSTRUCTION – A NECESSARY FACTOR FOR
SUCCESSFUL SOLUTION OF PRODUCTION AND ENVIRONMENTAL PROBLEMS IN
OPEN-PIT MINES
M.Eng. Ivan Kamenov - GEOPROJECT EOOD
e-mail: i.kamenov@geoprojectbg.com
M.Eng. Angel Tomov - GEOPROJECT EOOD
e-mail: a.tomov@geoprojectbg.com
ABSTRACT
In the Republic of Bulgaria there are no large mineral deposits, except the following
copper ore deposits: Ellatzite, Assarel and Chelopech. These ore fields, excluding Chelopech,
have been exploited by applying the opencast mining method. The already existing mines in these
localities have induced certain problems due to complicated mining-geological and hydrotechnical
conditions. In order to create safer working conditions in the two largest opencast mines, some
technical solutions have been adopted for surface and underground drainage and dewatering of
the mine terrains. For this purpose, underground drainage workings have been built and put into
operation and a programme for construction of new underground facilities has been specially
developed.
The opencast method of extraction in Ellatzite mine has induced certain problems
concerning environmental protection. The dewatering and drying of the mine have caused
contamination of the nearby rivers. For this purpose, wastewater treatment facilities have been
built and continue to be under construction. A local wastewater treatment plant for part of the mine
drainage waters has been built up and a new wastewater treatment facility is now being
constructed after the design of Mitsubishi, which will allow treatment of the remaining mine waters,
discharged from the open pit.
In order to provide safe conditions for execution of all mining operations in these open-pit
mines, it is considered appropriate to perform drainage and dewatering by building underground
mining facilities. This report describes in chronological order the measures and activities
undertaken to ensure the normal production process in Ellatzite mine, combined with technical
solutions for coping with environmental problems. The dewatering of Ellatzite copper deposit has
induced environmental problems for the water protection of the Malak Iskar River. It is a typical
characteristic of Ellatzite mine that water-catchment and separation of contaminated and clean
waters on the territory of the mine has been mainly performed through underground mining
facilities in order to protect the environment. For Ellatzite mine this scheme has proved to be
efficient and will be applied in the future development of mining operations according to the
respective need.
The report reveals a chronological retrospection of the underground facilities, which have
been built to provide successful solution of production and ecological problems, as priority is given
to those projects related to environmental protection.