Environmental association of iron minerals and iron concentrations in soils close to abandoned manganese mine - a multivariate analytical approach

Environmental association of iron (Fe) minerals and Fe concentrations in soils close to the Kgwakgwe Mn oxide ore abandoned mine, Botswana are investigated in this study. Four hundred soil samples were obtained from a 4 km2 area close to the abandoned mine. The Fe minerals in the soil samples were identified by x-ray diffractometry and the Fe concentrations by atomic absorption spectrophotometry. Results were processed using the statistical package for social science (SPSS). Iron minerals namely hematite and goethite were found in soils from the study area but only hematite in soils from the control site. Also Fe concentrations in soils from the study area were significantly higher than those from the control site. The correlations depicted very weak associations of these parameters. Hematite contributed significantly in the formation of the five clusters, goethite's contribution was for three of the clusters, and Fe concentrations in soils were for two of the clusters. At Kgwakgwe, exposed surfaces of mine workings, ferruginous shale and country rocks through wind erosion release particulate air matter, rich in Fe into the atmosphere which are transported over short distances and deposited on soils. Through chemical alteration processes, hematite is hydrated to goethite and neomineralization of goethite from the ferruginous shale occurs in the surrounding soils

Environmental association of iron minerals and iron concentrations in soils close to an abandoned manganese mine – a multivariate analytical approach

Environmental association of iron (Fe) minerals and Fe concentrations in soils close to the Kgwakgwe Mn oxide ore abandoned mine, Botswana are investigated in this study. Four hundred soil samples were obtained from a 4 km2 area close to the abandoned mine. The Fe minerals in the soil samples were identified by x-ray diffractometry and the Fe concentrations by atomic absorption spectrophotometry. Results were processed using the statistical package for social science (SPSS). Iron minerals namely hematite and goethite were found in soils from the study area but only hematite in soils from the control site. Also Fe concentrations in soils from the study area were significantly higher than those from the control site. The correlations depicted very weak associations of these parameters. Hematite contributed significantly in the formation of the five clusters, goethite's contribution was for three of the clusters, and Fe concentrations in soils were for two of the clusters. At Kgwakgwe, exposed surfaces of mine workings, ferruginous shale and country rocks through wind erosion release particulate air matter, rich in Fe into the atmosphere which are transported over short distances and deposited on soils. Through chemical alteration processes, hematite is hydrated to goethite and neomineralization of goethite from the ferruginous shale occurs in the surrounding soils. Journal of Applied Sciences and Environmental Management Vol. 10(1) 2006: 31-3

Physico-chemistry of continental Bentonites and Kaolin for ceramic applications

Growing demand for bentonite and kaolin applications in the ceramic industry motivated this study which aimed at physico-chemically characterizing some selected continental clayey materials from Botswana, Mozambique, Pakistan, Senegal, South Africa and the United States of America. The hydrogen ion concentration (pH),  electrical conductivity (EC), cation exchange capacitance (CEC), specific surface area (SSA) and color were determined. The results depicted that the pH values were between 5.8 and 10.5, EC values ranged from 200 ìS/cm to 6501 ìS/cm, CEC values occurred between 3.5 meq/100 g and 105 meq/100 g, and the SSA values were between 4 m2g-1 and 19 m2g-1. Raw clay color ranged from white to black with most samples having a greyish-like appearance. These values are in conformity with those obtained by other researchers, and based on their physico-chemical characteristics, the clayey materials were found to be suitable for use in the ceramic industry

Mineralogical Appraisal of Sediments of Duricrust Suites and Pans around Jwaneng Area, Botswana

A mineralogical investigation of duricrust suites in Letlhakeng valley, and five pans around Jwaneng in Botswana was undertaken in order to know the mineral assemblages and infer on their landscape formation. In Letlhakeng, duricrusts comprised calcretes, silcretes and ferricretes. Calcretes were dominated by the minerals: calcite, quartz and to a lesser extent dolomite. Silcrete mineralogy was dominated by quartz, opal, and some occurrences of palygorskite, microcline and rutile. The intermediate forms of cal-silcretes yielded quartz, muscovite, and kaolinite. Ferricretes occurred on an area of the valley capping, with minerals dominated by goethite and haematite. The indurates are believed to have been formed through groundwater mechanisms. The general lowering of the valley, led to precipitation of the duricrusts. The pans were dominated by calcrete and silcrete only. The calcretes mineralogy was mainly calcite, dolomite and quartz. Illite-montmorillonite and sepiollite were also present. Samples of pan clay floor, other than being dominated by calcite, dolomite and quartz, also had sepiollite ferrian. Pans and valleys are accumulation sites, with polygenetic modes of genesis. The duricrusts have undergone several alterations throughout time

Multivariate analyses of heavy metals in soils and Colophospermum mopane leaves around the Selebi Phikwe nickel-copper mine and smelter/concentrator plant area, Botswana

This study was conducted in order to ascertain levels of concentrations and areal distribution of heavy metals in the surface soils and vegetation around the Selebi Phikwe Ni-Cu mine and smelter/concentrator plant, Botswana. One hundred and forty samples each of soil and Colophospermum mopane leaves obtained from ten sites, were analyzed by atomic absorption spectrometry (AAS) technique for their concentration levels of Cu, Ni, Fe, Cr, Co, Cd, Zn and Se. Data analysis was done mainly using the statistical package for social science (SPSS). Multivariate analysis was used to determine the distribution of metals within the study area. Concentration values obtained for analysed soil samples were as follows: Cd ranged from 0.01 to 0.05 ppm; Co from 1.0 to 28 ppm, Cr from 0.03 to 14 ppm; Cu from 11 to 116 ppm; Fe from 31 to 430 ppm; Ni from 19 to 120 ppm; Se from 0.01 to 0.03 ppm, and Zn from 17 to 68 ppm. The concentration values obtained for analysed mopane leaves were as follows: Cd was between 0.01 and 0.05 ppm, Co ranged from 1.0 to 28 ppm; Cr from 0.03 to 11 ppm; Cu from 4 to 116 ppm; Fe from 31 to 430 ppm; Ni from 19 to 120 ppm; Se was between 0.01 and 0.03 ppm, and Zn was between 17 and 79 ppm. In general heavy metals concentrations in both soils and vegetation depended on the site and proximity of the sampling locations to the mine. The findings of the study depicted that concentrations of heavy metals in soils and leaves of colophospermum mopane decreased with increase in distance from the mine and smelter/concentration plant. @JASE

Physico-chemical, Mineralogical And Chemical Considerations In Understanding The 2001 mabeta New Layout Landslide, Cameroon

Landslides are part of natural catastrophic disasters destroying both biological and physical entities including loss of human lives. An evaluation of soil properties involved in landslides is significant in its management. To this effect, soil samples from the 2001 landslide occurrences in the Mabeta New Layout, Limbe, Cameroon were analysed using standard techniques to determine texture, pH, electrical conductivity (EC), bulk density (Db), water absorption percent (WA), linear shrinkage, plasticity index (PI), loss-on-ignition (LOI), mineral content and major cations. Results obtained were: bulk density (0.89 \u2013 1.08 g/cm3), LOI (19.4 - 25.7%), water absorption (23.4 \u2013 29.1%), linear shrinkage (5.4 \u2013 8.3%), volume shrinkage (4.8 \u2013 8.5%), PI (13.5 \u2013 20.75%), major cations ((Fe2O3 : 9.91 \u2013 23.24%), (Al2O3 : 9.88 \u2013 28.48%), (CaO : 0.73 \u2013 1.3%), (MgO : 0.55 \u2013 2.80%), (K2O : 1.06 \u2013 1.59%), (Na2O : 0.77 \u2013 0.89%)), pH (5.17 \u2013 6.90) and EC (16.53 \u2013 149.20\u3bcS/cm). Values from physico-chemical analyses, secondary minerals abundance index (SMAI) and chemical index of alteration (CIA) of the soils were reflective of particles with high potential for sliding. With major contributions from favourable slope, seismic and hydrologic forces, the event occurred

Headaches Among Residents Within the Selebi Phikwe Nickel-Copper Mining Environment, Botswana

Headache occurrences among different classes of residents within a nickel-copper (Ni-Cu) mining and smelting environment in Botswana are investigated using questionnaires and statistical package for social sciences (SPSS). Interpreted results from respondents indicated that all of the health service providers, 80% of educational institutions, and 70 % of businesses enterprises had patients, learners and workers respectively, and 77 % of individuals, complained of one form of headache or the other. Similar high values were obtained when responses were considered according to study sites, especially for frontal and temple headaches. Females suffered slightly more often from headaches than males. Values for sites close to smelter/concentrator plant and mine were in general higher. Mining activities especially the release of sulphur gases and fumes into the atmosphere, and other climatic factors could possibly be contributory to the rampant occurrence of headaches at Selebi Phikwe

Soil Heavy Metal Concentration Patterns at Two Speed Zones along the Gaborone-Tlokweng Border Post Highway, Southeast Botswana

Since 1988 Botswana has been experiencing an unprecedented increase in vehicular traffic which is suspected to be having contamination effects on soils along heavily used roads in the country. This study aimed at understanding the contamination trends of heavy metals on soils due to vehicular emissions. The soil physico-chemistry (bulk density, particle size distribution, pH, electrical conductivity and cation exchange capacity), mineralogy (using x-ray diffraction techniques) and heavy metals (Cd, Pb, Cu and Zn) concentrations were determined for soil samples obtained along the roadside at 2m, 4m, 6m and 100 m of the Gaborone - Tlokweng Emigration/Immigration Boarder Post Road, which is one of the busiest in the country. Bulk density of soil samples were from 1.19 to 1.4; and sand, loamy sand and sandy loam textural classes constituted the soil samples. The soil pH was from 5.09 to 8.57; the EC ranged from 6.27 \u3bcS cm-1to 20.3 27 \u3bcS cm-1 and the CEC values were from 10.2 meq100g-1 to 27.2 meq100g-1. Clay minerals were identified in the samples as well as feldspar and quartz. The concentration levels for Pb were from 0 mgkg-1 to 71 mgkg-1; Zn were from 5.23 mgkg-1 to 51.26 mgkg-1 ; Cu were from 0.3 mgkg-1 to 18.1 mgkg-1 and Cd 0 mgkg-1 to 2.4 mgkg-1 . The interplay of soil physico-chemistry and mineralogy on heavy metals concentrations is discussed. Although levels of heavy metals concentrations fell below normal ranges, the values obtained were generally higher than those from some developed and developing countries. @JASE

Fourier transform infrared spectrophotometry and X-ray powder diffractometry as complementary techniques in characterizing clay size fraction of kaolin

This study aimed at demonstrating complementary roles offered by both Fourier transform infrared (FTIR) spectrophotometry and x-ray powder diffraction (XRPD) techniques in characterizing clay size fraction of kaolins. The clay size fraction of kaolin samples obtained from Kgwakgwe, Makoro, Lobatse and Serule kaolin occurrences and deposits in Botswana were characterized using laser diffraction particle size analyzer (LDPSA), FTIR spectrophotometry and XRPD techniques. More than 70 wt % of the clay size fraction of these samples were < 4 μm. Main peaks in the infrared spectra reflected Al-OH, Al-O and Si-O functional groups in the high frequency stretching and low frequency bending modes and were those for kaolinite but possible absorption interference peaks for quartz, smectite and muscovite are inferred. The XRPD results identified kaolinite as the major mineral phase with confirmed presence of quartz, smectite and muscovite as minor quantities in the samples. The findings therefore suggest that XRPD technique could be used as a complementary tool when characterizing the clay fraction of kaolin using FTIR spectrophotometry. @JASE

X-ray diffraction study of kanwa used as active ingredient in achu soup in Cameroon

In this study, x-ray powder diffractometry (XRPD) technique was used to identify the mineral constituents of kanwa; an earthy material widely used as active ingredient in achu soup and other vegetable soups in Cameroon and several other West African countries. Results depicted trona (Na3H (CO3)2.2H2O) to be the main mineral constituent. It reacts with palmitic and oleic acids in palm oil and both sodium palmitate and sodium oleate are produced which are responsible for the unique, characteristic and cherished taste of achu soup.Keywords: X-ray powder diffractometry, kanwa, achu soup, Cameroo