Browsing by Author "Sackey, Michael Ampim"

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    Analysis of financing mineral projects in Ghana
    (2003) Sackey, Michael Ampim
    The mining sector of Ghana is a major contributor to government revenue in the form of export earnings (currently 40 percent) and Gross Domestic Product (11 percent). The bulk of capital for financing this sector is external and foreign based, with little contribution from the Ghanaian financial institutions and market. The economic potential of the country can be fully exploited in the mineral industry with the Ghanaian participation in financing these operations. This research investigates the type and sources of financing large-scale mining operations in Ghana within two distinctive periods, the Pre-Structural Adjustment Period (Pre-SAP) and the Post-Structural Adjustment Period (Post-SAP). The collection of primary data was acquired from operating large-scale mining companies in Ghana and some financial institutions, through the administration of questionnaire. The questionnaire was analysed statistically to generate meaningful information. The types and sources of finance for the sector in the Pre-SAP period includes parent company (23.8%), skilled labour loan (14.3%) debt financing (23.8%), equity financing (4.8%), delayed payment (9.5%) and import-export financing (23.8%). Financing during the Post-SAP period took different turn and dimensions although some of the types and sources in the previous period Pre-SAP were employed. During the Post-SAP, the sources and types of financing include; debt/loan (17.2%), equity financing (10.8%), parent company (14. 1%), delayed payment (15.6%), takeover/joint venture (7.8%), hedging (6.3%), equity shares (14.1%) and import-export credit (14%). Comparing the two periods, the types and sources of capital increased in number and this can be attributed to the stable political scene and economic adjustment. In order to encourage the Ghanaian participation in financing large-scale mining operations in Ghana, this thesis recommends strengthening and restructuring the Ghana Stock Exchange to cover some West African countries and encourage the Ghanaian financial institutions to invest some of their profits in the mining sector through the Ghana Stock Exchange.
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    Groundwater contamination through cyanide and metal migration from tailings dam operation
    (April, 2016) Sackey, Michael Ampim
    In the gold industry, only a few hundredths of an ounce of gold may be produced for every tonne of tailings generated. Tailings need to be properly managed because they constitute a major source of release of many metals and trace elements into the environment which is a potential source of groundwater contamination. The impact of Gold Fields Ghana Limited (GFGL) tailings dams were evaluated by chemical characterisation of metals and trace element concentrations in the decant pond, tailings slurry and underdrainage sump. The attenuation properties of the substrata were also evaluated with emphasis on hydraulic conductivity, permeability characteristics and geochemical properties (pH, Organic Matter Content (OMC), Cation Exchange Capacity (CEC), iron oxide (Fe2O3) and Anion Exchange Capacity (AEC). Finally, four years groundwater monitoring data was used to evaluate the impact of possible seepage from the dam. Results of the studies indicate that concentrations of Weak Acid Dissociable (WAD) cyanide and Total cyanide increased significantly with depth in the decant pond. pH of the pond is alkaline with mean values ranging from 9.3 to 10.6 corresponding to mean pH values in the tailings slurry at spigotting points and underdrainage sump. Total cyanide concentrations ranged from 0.36 mg/l to 1.11 mg/l over five meters depth and 0.10 mg/l to 0.29 mg/l over ten meters depth in the decant ponds of TSF 1 and TSF 2 . WAD cyanide concentrations ranged from 0.26 mg/l to 0.93 mg/l and from 0.01 mg/l to 0.16 mg/l over five and ten meters of decant depth respectively. Significant metals identified in the decant pond, underdrainage sump and tailings slurry were Sodium (Na) and Magnesium (Mg) with trace elements being Iron (Fe), Copper (Cu), Manganese (Mn), Arsenic (As), Nickel (Ni), Zinc (Zn) and Chromium (Cr), whiles alkali metals identified were Calcium (Ca) and Potassium (K). These metals and trace element were consistently present in the tailings and underdrainage. Low hydraulic conductivity and a combination of low acidic pH, relatively high Anion Exchange Capacity (AEC) and low Cation Exchange Capacity (CEC) were identified to be the major driving attenuation properties that favour cyanide attenuation in the Tailings Storage Facility (TSF) basin. The average concentration of Total cyanide detected within a radius of 3 m at the field leaching stations is 0.02 mg/l, constituting 99.9% attenuation of cyanide introduced. The hydraulic conductivity and permeability values computed from grain size analyses of the substrata material are 4.3 x 10 -6 to 9.7 x 10 -6 m/min and 6.1 x 10 -12 to 13.9 x 10 -11 m/min respectively. The TSF sub-strata material has a pH range of 4.3 to 4.8, a CEC range of 1.92 to 2.89 meq/100g and an AEC range of 881.25 to 1278.25 meq/l. The attenuation rate of cyanide at the five (5) stations remained constant at 0.021 mg/l/hr as time increased. Based on significant increase in levels of EC and pH levels as well as concentrations of Na, Ca, and Cl, it could be established that monitoring boreholes along the toe of TSF1 and TSF2 have received seepage from the tailings facilities. Similar concentrations were observed in boreholes at the South heap leach facility, specifically near the pregnant pond, monitoring boreholes located west of the North heap leach Facility and specifically around the South and North containment ponds