Chemistry for Sustainable Development 15 (2007) 329-342 Processes of Chemical Weathering of Minerals in Sulphide-Containing Tailing Dumps: Modeling of the Composition of Vadose Water and Secondary Phases

Abstract Thermodynamic model of the oxidative leaching of sulphide-rich tailings from dressing of gold-containing ores (Berikul settlement, West Siberia) is investigated. When calculating the water-rock interactions, we applied some special approaches allowing one to determine the effect of the degree of reaction progress and change of the parameters of the medium (E h , pH) on the composition of the formed secondary minerals that restrain the development of acid drainage at the objects of this kind. Substantiation of several stages of the formation of a technogenic system in time and space is presented, depicting the approach of the system to equilibrium with the environment. The distinguished stages correspond to the zoning of mineral associations described at the object. These associations were formed during 50 years of storing the tailing mounds from the lowest weakly oxidized sulphide parageneses with gypsum and covellite to the capping jarosite-quartz-gypsum zones. The results of modelling provide evidence that an increase in rock affection by atmospheric water brings about the conditions favourable for the formation of the "final" association (goethite and quartz); however, this association is not stable even on the surface of the Berikul tailing dump. It is concluded on the basis of preliminary evaluation that hypergenesis processes in the objects of this kind may proceed hundreds of years till complete depletion of the acid-producing and toxic potential of industry-related wastes

Experimental Studies on Heavy Metal Sorption by Natural Clays Aimed at Drain Water Purification

Abstract Sorption properties of bentonite clays of the Kamalino deposit (Krasnoyarsk Territory) have been studied for the purpose of their possible use for purifying the wastewater of sulphide-containing tailing pits from heavy metal ions. By the example of copper (II), an effect of pH value, of sorbate/sorbent ratio and sorbate concentration increase on the redistribution of metal from model solution to the solid phase. Basing on the data concerning the investigation of water extracts from the substance of the Belovo Zinc Plant (Kemerovo Region) and its wastewaters drain the present object is established to be the source of the acidic mine drain age of the most adverse type (insignificant iron content as well as high heavy metals and sulphate sulphur content). It has been demonstrated efficient results concerning wastewater treatment of the Belovo Zinc Plant tailing pits could be obtained with the use of two-stage purification: first, with the application of calcite, and further via the interaction with a clay sorbent

Chemistry for Sustainable Development 20 (2012) 375384 Features of Soil Pollution in the Region of Storage of the Wastes from Pyrometallurgical Zinc Extraction at the Belovo Zinc Plant

Abstract Total heavy metal content in the soil in the region of the storage of wastes from pyrometallurgical works (Belovo Zinc Plant) was investigated. It was established that the high level of zinc and copper pollution is conserved also after the plant stops its operation. The maximal pollution was detected in the direct vicinity of clinker mound; it exceeds the background values for zinc by a factor of 60. At a distance of 300 m pollution decreases (17-fold excess over the background value) but it can be followed even at a distance of 5 km from the Belovo Zinc Plant (5-fold level). The fraction of mobile forms of a number of elements extracted through stepwise leaching was determined. For the soil with the heaviest pollution (ðÍ of water extract 5.58), the fraction of mobile zinc forms exceeds the MPC by a factor of 66, copper by a factor of 2, manganese is below the normal value, mobile forms of nickel were not detected. Thus obtained row depicts the geoecological condition of soil in the region of waste storage of the Belovo Zinc Plant