ECOLOGICAL ASPECTS OF THE TECHNOGENIC DEPOSITS PRESERVATION OF NON-FERROUS METALS IN THE NORTH CAUCASUS

The article presents the results of research on a comprehensive assessment of techno genic waste deposits located in the North Caucasus region, gives a brief description of the material composition of techno genic raw materials, element-by-element quantitative reserves that are part of the accumulated secondary georesources for their possible utilization, production of non-ferrous metals and raw materials for the manufacture of industrial building materials. The article considers the sanitary and ecological parameters of the functioning of man-made raw materials in complex orographic, meteorological and geographical conditions. The critical aspects of the preservation of techno genic waste deposits in the current anthropogenic conditions are identified. The risk factors for the removal of toxic and harmful geomaterials into the water area with significant harm to the flora and ichthyofaunal are identified. For a deeper assessment of the minerals contained in the extracted ore, a unified state register of techno genic waste deposits should be created, Taking into account the high fragmentation of all the above – mentioned process links at the present time , the owners, taking into account the current sanitary and regulatory requirements, must take adequate measures to ensure the regulatory and environmental requirements in accordance with the current Federal Law “On Production and Consumption Waste”. The need for complex processing of waste from mining and processing industries in the North Caucasus is also dictated by environmental aspects due to the high risk of the occupied territories (they are located in floodplain terraced areas of mountain rivers) due to the flooding of mountain rivers, including the high vulnerability of resort and recreational and balneological complexes due to the negative impact of these negative sources. The assessment of the useful components contained in the extracted ore is currently not carried out in full, and the accumulated waste from processing non-ferrous metal ores is used in small volumes.

ASSESSMENT OF STRONTIUM, RUBIDIUM AND SCANDIUM STATUS IN SOILS AFFECTED BY SOLID WASTE DEPOSITS

The aim of the study was to assess the level of contamination of soil with strontium, rubidium and scandium in the solid waste deposits. The study was performed on soil samples collected from Moldova Noua, southwest of Romania, an area with historical anthropogenic history. The soil analysis was performed using X-ray fluorescence (XRF). The samples were collected from five collection points using a random pattern from around the illegal waste deposit and all analyses were performed in triplicate. To assess the influence of wastes on the soils concentration levels of strontium (Sr), rubidium (Rb) and scandium (Sc), were calculated contamination factors (CF), and pollution index (PIL) by reporting the concentration of the investigated elements of the upper earth crust concentrations and geo-accumulation index (Igeo) calculated by reporting the elements concentration values to a control sample, used as reference. The reference sample was collected from an area close to the waste deposit but located in a protected green area. The results show that from the investigated elements, scandium is the element of concern, the soil presenting a moderate contamination level with this element.

The Mechanism of Amphoteric Metals Cations Immobilization into Clay-Cement Mixtures

The article presents the possibilities of using special prepared binders to reduce the emission of ions from soil, and immobilize metals migration from waste deposits. Clay-cement slurries are mixtures containing in their compositions clinker binder and clay minerals, in this case they were Bełchatów and Koniecpol clays. After hydratation process mixtures they create flexible and tight structures that are used, among others, as a barriers immobilizing the spread of pollution. The tests have shown that in the case of amphoteric metals, it is possible to accumulate almost 100% of the contamination using clay-cement suspensions. An attempt was also made to explain the mechanisms of ion retention in arised structures. The article presents three probable mechanism of amphoteric ions binding, the first is retention in the clay minerals interlayer spaces, the second is entrapment in CSH type phases formed during hydratation. Last possibility is formation of some new silicate structures.

Some problems of the legal regime of lands under waste deposit

The study of problematic issues of the legal regime of lands under waste deposits. During the study, the author analyzed some general concepts of land law provided by domestic scholars, in particular: the category of land and the legal regime of land, as well as on their basis, proposed their own definitions. Having conducted an in-depth analysis of scientific works in the field of land law, the author stated that the concept of «subcategory of lands» remains undisclosed. In order to classify land under landfills as a category of land, the category of land for industry, transport, communications, energy, defense and other purposes was considered in detail. For the same purpose, the author analyzed a number of regulations act that in one way or another establish the legal regime of land under landfills. As a result of the study, the author of the article concludes that to date there is no law that would establish the legal regime of lands under waste deposits. Keywords: legal regime, lands under waste deposits, category of land, subcategory of land, land for other purposes

Self-burning coal mining residues – an environmental issue or a source of raw materials?

<p>The self-burning of coal mining residues disposed at environmental conditions have been described in the literature as a phenomenon occurring worldwide. These coal related fires are of significant concern because of the risks to environment and human health due to the emission of harmful gases and particulate matter to atmosphere. Another concern is the degradation of soils and waters in surrounding areas owing to the mobilization and leaching of hazardous elements. The self-burning of coal mining waste deposits may be a very persistent phenomena over decades. The carbon content (combustible fraction) and chemical composition of coal waste materials (and some physical properties) are the most relevant factors that influence intensity and duration of the self-burning process. The comprehensive characterisation of coal waste deposit materials provide information on the self-burning process and above all useful insights about the propensity to ignition and burning and their environmental impacts. The characterization of coal waste materials can contribute to assess their reuse as a secondary source of critical raw materials and carbon based materials.</p><p>The recycling of these materials, from both burning and non-burning coal waste deposits, is in good agreement with recommendations from European Union (EU) pointing out the need for developing sustainable recovery of mining and industrial wastes to mitigate environmental impacts. The EU identifies 26 critical raw materials including inorganic trace elements and natural graphite as a critical raw materials with extremely high level of external dependence, and strongly recommends the development of measures to increase recycling of by-products and residues. In this framework, research has been dedicated to burning or already burned coal mining waste deposits in Portugal and Spain. Non-burning coal mining waste deposits from the same mining areas have also been investigated. These coal waste deposits, resulted from the discharging of coarse mine refuse from mining exploration. They are very heterogeneous and present variable amounts of coal that is the combustible fraction. The comprehensive characterization of mining waste materials as well as the identification of products formed during combustion reveals the potential environmental impact, principally due to the concentration of volatile organic compounds emitted to atmosphere. The combustion process also causes changes in trace elements’ mode of occurrence with some becoming more easily mobilised for surrounding soils and water systems by percolation or deposition of solid atmospheric particles. On the other hand, the mining waste burned materials reveal an enrichment of some trace elements, including critical raw material; and, the production of graphitic structures, including graphene. Therefore the coal wastes mining deposits are an environmental issue, they can be seen as an alternative secondary source of critical raw materials and carbon based materials.</p>