Jarkynai Usubalieva (Kyrgyzstan)

Email: s029218 @matsu.shimane-u.ac.jp

Thesis title:  Ecological and geochemical assessment of technogenic mineral developments and ways of their multiple use.

Supervisor:  Prof. H. Ishiga (2002-2004).

The aim of my research is to make an ecological threat assessment of technogenic formations which contain the wastes of REE and metallic element (Pb, Zn, Cu, Mo, Cd and others) ore beneficiation, and also to estimate the resource they represent. The subjects of my study are the tailing ponds of the Ak-Tuz Mining Plant in Kyrgyzstan. These ponds contain some five million cubic meters of waste, spread over an area of 21 hectares. Stored wastes of this type can be considered from two angles: as sources of negative impacts on the environment; or as geological resources which may be exploited in future. Valuable concentrations of some elements remain in the tailings due to non-comprehensive processing of the ores. I will carry out quantitative determination of the components in the tailings using XRF and INAA, and assess their mobility using elution tests. This will permit me to characterize the elements and their combinations according to toxicity. The final part of my investigation is the evaluation of technological features and development of recommendations for their comprehensive use.

The ecological problems of the mining industry are actually an issue of waste utilization. Thus, the objectives of this work are to identify the impact of technogenic formations upon the environment, taking into account the nature (water, soil, air) and intensity of pollution, and the economic expediency of waste exploitation. It is necessary to understand the processes that are operating in the tailing ponds and the ways in which contaminants are transmitted in order to develop optimal waste location parameters to prevent environmental pollution.