The objective of this project was to investigate the current state of the practice with regards to karst detection methods and current karst construction practices and to recommend the best practices for use by the Virginia Department of Transportation (VDOT). A comprehensive review of literature available on the subject was conducted. Various karst detection technologies were summarized with r...

This paper presents a study about the potential of spectral unmixing of hyperspectral satellite image data for targeting and quantification of mineral content in limestone and bauxite rich areas in southern India. ASTER image (acquired in the VNIR and SWIR regions) has been used in conjunction with SRTM – DEM and field studies. A new approach of spectral unmixing of ASTER image data delineated ...

Bauxite residue is an important by-product of the alumina industry, and current management practices do not allow their full valorisation, especially with regard to the recovery of critical metals. This work aims to test the efficiency of ion exchange resins for vanadium (V) removal and recovery from bauxite residue leachates at alkaline pH (11.5 and 13). As an environmental pollutant, removal ...

Aluminum is currently the most widely used non-ferrous metal, and its extraction and purification from geological stores exceeds that of any other metal except iron (1, 2). In 2013, global primary aluminum production was ~52 million tons (104 billion pounds) or about 15 pounds for very person on the earth (1–4). The global outlook for aluminum demand from developing countries such as Brazil, Ch...

Strong karstlize effect forming surface and underground double-space structure in karst area, what resulting groundwater systems are extremely sensitive to outside interference. This article mainly focuses on the vulnerability assessment of karst groundwater, proposing that the vulnerability assessment of karst groundwater should be considered from three perspectives: the inherent vulnerability...

In this paper the results of a leaching kinetics study of bauxite ore with sodium hydroxide are presented. The effect of ore particle size, sodium hydroxide concentration and reaction temperature on the Al2O3 extraction rate was determined. The results obtained showed that 99% of Al2O3 was leached out using -200+270 mesh ore particle size at a reaction temperature of 105 °C for 60 min reaction ...

The term “karst” applies to a distinctive type of landscape that develops from the dissolving action of water on soluble bedrock (Figure 11.1)—primarily limestone and marble but also dolostone, gypsum and halite. Karst landscapes are characterized by fluted and pitted rock surfaces, shafts, sinkholes, sinking streams, springs, subsurface drainage systems, and caves. The unique features and thre...

Production of Metallogenic-prognostic map (MPM) was preceded by the preparation of instructions that define three phases of work: preparation (with preparation of the Project), realization of field and laboratory research and data processing with production of different maps and, finally, production of the prognostic map with the accompanying instruction book. During the Project realization, th...

The karst hydrological processes are the response of karst groundwater system to precipitation. This study provided a concept model of karst hydrological processes. The hydraulic response time of spring discharge to precipitation includes the time that precipitation penetrates through the vadose zone, and the subsequent groundwater pressure wave propagates to a spring outlet. Due to heterogenei...

Exposed limestone karst landscapes, especially in the tropics, are often home to distinctive and specialized biotas. Among vertebrates, a particularly large number of karst-associated lizard taxa have been described, but for the vast majority, evidence of specific adaptions to karst is lacking. A number of studies, however, have provided evidence of consistent morphological trends in lizards th...