Results of the “Technogenic wastes of RA mining industry: problems and ways of their solution” round table – seminar, organized by YSU “Sustainable Development Center” in October, 2013
Among the participants were representatives of the OSCE Yerevan office, non-governmental and research organizations and civil initiatives of Armenia (“Association for Sustainable Human Development” Armenian “Aarhus” Center, Vanadzor “Aarhus” Center, YSU Scientific – Educational Center for Environmental Law, “Ecological Union, “Ecological Academy” NGO, “Healthy Hrazdan”, “Burning Star”, et al.) and other individuals, as well as employees of YSU departmental and research centers, and students. The meeting was presented by the YSU PR administration.The meeting was opened by the Head of YSU SDC, Head of the Board of Geological Prospecting and Surveillance of the USU Department of Geography and Geology, PhD in Geology and Mining Ruben Movsisyan, with a presentation “Technogenic Wastes of RA Mining Industry: Problems and Ways of Their Solution”. The presentation was based on the results of researches and investigations implemented by the SDC employees and involved experts, with a support of OSCE Yerevan office.
An advanced level of the country’s economic development can be achieved through intensive extraction and processing of natural resources. However, the economic development of the country is primarily defined not by the amount of extracted raw materials, but by the possibilities of their rational, civilized and innovative methods of their usage: thorough processing of mining extractions, distribution of profits of mining materials’ consumption, et al.
In developed countries, the amounts gained through exploitation of entrails are directed to creation of research intensive, technological and raw material saving advanced production areas. In these countries, the technical – economic essence of economy is being redirected towards the solution of social – economic problems of the country.
The contemporary civilized countries consume huge amounts of mining materials, and the vast majority of this amount goes to waste. The mass of mining material extracted per capita is 50 tons, of which 48 tons finally is transferred into waste, i.e. only 4% is being used.
In RA, large volumes of mining wastes are accumulated and continue to be accumulated. These are technogenic mining aggregations. The volumes of these wastes increase rapidly, mainly due to metal mines, of which the majority are operating in a strip mining way.
At present, about 20 tailings exist in RA, only 7 of which are conserved. One of them is in construction stage, while the other are operated in different ways. Taking into account the annual output plans designed for the mines, the assessment of the annual volume growth rate of tailings on the territory of the Republic will be up to 12 – 14 mln m3, that is 20 – 22 mln tons. Adding the amount of stripped rocks and wastes from overbalance rocks, we obtain a gigantic amount of 40 – 45 mln tons. However, despite of these deficiencies, a certain part of the waste can be used as a secondary mining raw material for production of construction materials and additional extraction of metals.
The work was implemented in several consecutive stages.
First, the level of detriment caused by non-utilizable waste has been assessed, and possible ways of decreasing their environmental impact had been identified.
On the second stage, the possible mining capacity of waste has been evaluated on the base of 3D model of Voghji waste dump, with application of economic indices.
The summary of obtained results implemented on the third stage provided an opportunity to submit certain proposals related to the current legislation, increase in the efficiency of mines, thorough investigation of waste dumps and formation of new ones.
In essence, the mining waste dumps can be divided in two main categories:
- A result of industrial extraction of mineral resources. These wastes include dumps of inclusive
and overburden rocks and overbalance dumps which had been processed only mechanically (crushing, transportation).
- Wastes originating during the processing of raw mining material: slime and benefication tailing stores, wastes of metal processing.
On the RA territory, the tailing stores are most risky ones among all types of waste, the next being dumps of overbalance rocks and, finally, stripping rocks. According to their level of deterioration, all tailings of mineral resources in Armenia are classified as having 2nd and 3rd level of deterioration. The most risky ones are the concentration tailings at Ararat gold mine, the next one being the active tailings of lead-zink, copper – molybdenum, and copper mines. This series is concluded by old, partially prolonged and well known tailing storages of nonferrous metals.
To decrease the deteriorative impact of waste dumps, it is necessary to render them harmless: extraction of natural and harmful components, production of construction materials, prolongation of residues. The latter includes soil coverage with herbaceous plants and creation of soil-chemical barriers.
Unlike the primary ores, the technogenic dumps are less rich. However, they have a number of advantages: the raw material is extracted, crushed and stored in the required area, etc.
The economic assessments revealed that in processing of tailings the 0.09% concentration of copper will provide 0% of profitability. The SX-EW process is considered as the most prospective way for reprocessing of technogenic wastes. This process is relatively safe, it secures a high level of extraction, does not require large capital investments and has a low cost price.
To justify the utilization of wastes as a technogenic mine, a large prolonged tailing at Voghji, where the concentration tailings of Kajaran mine were accumulated, was chosen.
To assess the tailing storage at Voghji, its 3D model has been developed, which was a condition sine qua non for evaluation of its real volume and distribution of components within it. The selection of model development was determined also by confidentiality of information regarding the tailings, and complicated character of their investigation. The final model will provide an opportunity to make some estimates about the capacities and component distributions in other similar tailings. As a result, sublayers rich in natural resources, and poor sections have been identified in Voghji tailing storage.
It has been revealed that the “rich” concentrations of copper are related to sand fraction (resources of 15 mln tons), and its utilization will secure a profit of $1.0 – 1.2 per ton. However, such a utilization will not lessen the total amount of tailings, and the implementation of industrial process will require a construction of large sites, which is impossible due to complicated profile of the gorge. Taking into account that the tailing is recultivated, at present it should be left intact, but rather should be surrounded by a soil – chemical barrier, with monitoring of its current state.
From the viewpoint of secondary utilization of wastes, the wastes stored in northern tailings at Akhtala, Shamlough and Alaverdi, as well as the slag at Alaverdi copper smelting plant, are of certain interest. There are 4 tailings in total, which are of small size (0.5 – 0.8 mln tons), and, unlike the southern tailing stores, the copper concentration in them, according to our estimates, is several times higher. The processing of these tailings will lead to $5 – 8 profit per ton. Along with the economic effect, this processing will provide also an environmental impact. At present, all tailing stores are in the worst state, they are leaching, more toxic, located in residence or adjacent areas.
All this evidences that it is purposeful to start the utilization of northern tailing storages. Along with metal extraction and deharming of risky components, it will be possible to produce a certain volume of construction materials for local needs and export. A railway is available in close neighborhood.
The dumps of overbalance rocks also are of high value. We suggest to initiate their processing in a cheap way of component flushing. The amount of overbalance oxidated ore in Kajaran mine is about 80 mln tons, with copper and molybdenum content 0.2% and 0.02% respectively. At Agarak mine 30 mln tons of oxidated ore is accumulated. This problem exists also in northern mines, where natural components of “high” non-extracted content are present in drills’ dumps.
It is worth note that the above presented data on metal content and amount should be considered as forecast resources of P1 category and not as industrial supply. Hence, the presented estimates are of preliminary character and need a justification through waste reconnaissance and geological – economic evaluation. The rough calculations show that the reconnaissance of tailings will require $5,000 – 6,000 per hectare.
Time factor is another important circumstance (formation of technogenic mines with predefined parameters). While forming technogenic dumps, one has to take into account their form, size, location conditions, loading ways, internal structure, quality of stored natural resources.
Coming from the results of implemented activities, we can come to following very important conclusions and submit specific proposals.
- Approval of changes and amendments in the law and Constitution. More specifically, an amendment to Constitution should be approved stating that the entrails and natural resources aggregated in it are the asset of present and future generations. The State must not only govern this asset, but (through Government) should be in charge of its rational utilization for the benefit of country’s citizens’ well-being.
- Bringing the legal frames related to entrails in conformity with international regulations.
- Development of a clear entrails utilization state policy.
- To increase the amount of state duties for exploitation of mines up to 60%, and to secure the expediency of expenses. Half of the amount gained from utilization of entrails should be provided to communities on whose territories the mine are located.
- To organize a registration and accurate assessment of the volumes of tailings and overbalance rocks’ dumps, investigation of useful and harmful components and compounds present in these dumps, calculations of supply and economic evaluation.
- To implement an engineering and hydro-geological reconnaissance of waste dumps’ conditions and define the level of components’ flushing in them.
- To organize the active dumps as future technogenic mines with a goal of their further utilization.
Numerous questions have been put on and answered during the active round table discussion, many proposals have been submitted. Participants highly evaluated the implemented work. In particular, member of the Community Council under the RA President, President of the “For Sustainable Human Development” NGO Karine Danielyan noted that within the frames of the “Sustainable Development Council” under the RA Government, currently an interdepartmental Commission on implementation of UN “Rio+20” summit’s resolutions in RA is being formed. According to K. Danielyan, the implemented work is of extreme importance from this viewpoint. In particular, the obtained results should be presented to the subcommission on “Entrails Utilization and Environment”, where the list of future activities in this direction should be developed.