Positional accuracy in the usage of GPS receiver is one of the major challenges in GPS observations. The propagation of the GPS signals are interfered by free electrons which are the massive particles in the ionosphere region and results in delays in the transmission of signals to the Earth. Therefore, the total electron content is a key parameter in mitigating ionospheric effects on GPS receivers. Many researchers have therefore proposed various models and methods for predicting the total electron content along the signal path. This paper focuses on the use of two different models for predicting the Vertical Total Electron Content (VTEC). Artificial Neural Network (ANN) and Adaptive Neuro Fuzzy Inference System (ANFIS) algorithms have been developed for the prediction of VTEC in the ionosphere. The developed ANN and ANFIS model gave Root Mean Square Error (RMSE) of 1.953 and 1.190 respectively. From the results it can be stated that the ANFIS is more suitable tool for the prediction of VTEC. Keywords: Artificial Neural Network, Adaptive Neuro Fuzzy Inference System, Vertical Total Electron
{"title":"Appraisal of ANN and ANFIS for Predicting Vertical Total Electron Content (VTEC) in the Ionosphere for GPS Observations","authors":"A. Ewusi, B. Apeani, I. Ahenkorah, R. Nartey","doi":"10.4314/GM.V17I2","DOIUrl":"https://doi.org/10.4314/GM.V17I2","url":null,"abstract":"Positional accuracy in the usage of GPS receiver is one of the major challenges in GPS observations. The propagation of the GPS signals are interfered by free electrons which are the massive particles in the ionosphere region and results in delays in the transmission of signals to the Earth. Therefore, the total electron content is a key parameter in mitigating ionospheric effects on GPS receivers. Many researchers have therefore proposed various models and methods for predicting the total electron content along the signal path. This paper focuses on the use of two different models for predicting the Vertical Total Electron Content (VTEC). Artificial Neural Network (ANN) and Adaptive Neuro Fuzzy Inference System (ANFIS) algorithms have been developed for the prediction of VTEC in the ionosphere. The developed ANN and ANFIS model gave Root Mean Square Error (RMSE) of 1.953 and 1.190 respectively. From the results it can be stated that the ANFIS is more suitable tool for the prediction of VTEC. Keywords: Artificial Neural Network, Adaptive Neuro Fuzzy Inference System, Vertical Total Electron","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":"25 1","pages":"12-16"},"PeriodicalIF":0.0,"publicationDate":"2017-12-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85627616","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The selection of optimal sites for mine waste dumps is a significant problem associated with surface mines operations. A number of factors such as financial, environmental and safety requirements must be simultaneously considered to avoid potential losses. This research used the ModelBuilder tool and several GIS spatial analyst tools to select suitable sites for mine waste dump. The weighted overlay technique was adopted by first determining the necessary criteria and constraints and subsequently developing attributes for each criterion. The criteria used were grouped into a binary category of suitable and unsuitable. A total area of 17.01 km 2 was determined as suitable, while 66.10 km 2 was classified as unsuitable after overlaying and weighting all the criteria. Out of the suitable areas, an area of 13.62 km 2 consisting of 21 sites were determined as optimal. Applying further constraints, 2 out of the 21 optimal sites were determined as the best sites. A step-wise model has been developed using ModelBuilder for selecting an economic but effective site for dumping mine waste using suitable constraints and criteria. This has facilitated the production of suitability maps generated from the various datasets being used for mine waste dump site selection. The final output map that best fits the criteria and constraints can be used by decision makers to set out the areas suitable for mine waste dump sites on the mine concession. The model could be applied as the standard model for selecting sites for mine waste dumps, since there is no standard model available at the moment. Keywords : ModelBuilder, GIS, Constraints, Waste Dumps, Weighted Overlay
{"title":"Selecting Suitable Sites for Mine Waste Dumps Using GIS Techniques at Goldfields, Damang Mine","authors":"P. Baffoe","doi":"10.4314/GM.V17I1","DOIUrl":"https://doi.org/10.4314/GM.V17I1","url":null,"abstract":"The selection of optimal sites for mine waste dumps is a significant problem associated with surface mines operations. A number of factors such as financial, environmental and safety requirements must be simultaneously considered to avoid potential losses. This research used the ModelBuilder tool and several GIS spatial analyst tools to select suitable sites for mine waste dump. The weighted overlay technique was adopted by first determining the necessary criteria and constraints and subsequently developing attributes for each criterion. The criteria used were grouped into a binary category of suitable and unsuitable. A total area of 17.01 km 2 was determined as suitable, while 66.10 km 2 was classified as unsuitable after overlaying and weighting all the criteria. Out of the suitable areas, an area of 13.62 km 2 consisting of 21 sites were determined as optimal. Applying further constraints, 2 out of the 21 optimal sites were determined as the best sites. A step-wise model has been developed using ModelBuilder for selecting an economic but effective site for dumping mine waste using suitable constraints and criteria. This has facilitated the production of suitability maps generated from the various datasets being used for mine waste dump site selection. The final output map that best fits the criteria and constraints can be used by decision makers to set out the areas suitable for mine waste dump sites on the mine concession. The model could be applied as the standard model for selecting sites for mine waste dumps, since there is no standard model available at the moment. Keywords : ModelBuilder, GIS, Constraints, Waste Dumps, Weighted Overlay","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":"52 1","pages":"9-17"},"PeriodicalIF":0.0,"publicationDate":"2017-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91051025","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The last few years has witnessed internationalisation of small scale mining in Ghana. The entry of migrant artisanal miners has brought losers and winners in the sub-sector, creating a myriad of socio-political problems. However, official attempts to curb it have exacerbated the systemic problem of mineral governance. This paper analyses the emerging challenges and opportunities posed by the entrance of migrant miners into the country with insights into the assumptions on resources and conflicts. It takes a closer look at the causes, effects and dynamics of confrontation and collaboration between migrant small scale miners and their counterparts in the host nation. It argues that the current governance system of small scale -mining based on national control over exploitation is anachronic and not well adapted to competitive, sustainable and fair management of mineral resources, and proposes a sustainable partnership to harness complimentary skills to avoid deepening the resources conflicts which have plagued the mining districts.
{"title":"Internationalisation of Artisanal and Small Scale Mining in Ghana: Opportunities and Challenges","authors":"G. Agyei","doi":"10.4314/GM.V16I2","DOIUrl":"https://doi.org/10.4314/GM.V16I2","url":null,"abstract":"The last few years has witnessed internationalisation of small scale mining in Ghana. The entry of migrant artisanal miners has brought losers and winners in the sub-sector, creating a myriad of socio-political problems. However, official attempts to curb it have exacerbated the systemic problem of mineral governance. This paper analyses the emerging challenges and opportunities posed by the entrance of migrant miners into the country with insights into the assumptions on resources and conflicts. It takes a closer look at the causes, effects and dynamics of confrontation and collaboration between migrant small scale miners and their counterparts in the host nation. It argues that the current governance system of small scale -mining based on national control over exploitation is anachronic and not well adapted to competitive, sustainable and fair management of mineral resources, and proposes a sustainable partnership to harness complimentary skills to avoid deepening the resources conflicts which have plagued the mining districts.","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":"5 1","pages":"20-27"},"PeriodicalIF":0.0,"publicationDate":"2016-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73663360","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In Ghana, community development is regarded by mine local communities as the most important aspect of Corporate Social Responsibility (CSR), to the extent that often community development is perceived to be a statutory responsibility of mining companies. Consequently, mine local communities demand for more and more, sometimes prohibitively expensive, contributions towards community development. The inability of mining companies to meet all the demands often leads to unsavoury relation between mining companies and their host communities with concomitant adverse effect on mining operations. This constitutes a business risk that needs to be addressed properly by shifting from the earlier practices of making voluntary contributions towards community development to making sustainable community development an integral part of the mining business. This paper presents the evolutionary strategic models, with differing principles and action plans, used by Golden Star (Bogoso/Prestea) Limited (GSBPL) over the years to manage the development of its Bogoso/Prestea Mine Local Community (BPMLC), videlicet from a poor Philanthropic Community Assistance Model (PCAM) to an improved but ineffective Community Driven Assistance Model (CDAM) and eventually to the current effective, successful CSR Agreements Model (CSRAM). The paper also highlights the lessons learnt from the negotiation process that led to formulation of the CSRAM as well as the benefits and successes resulting from its implementation and the challenges. It is concluded that mutual understanding, tolerance, transparency, trust, commitment and accountability are key to the successful management of CSR and community development. Keywords : Social Responsibility, Agreements Model, Mining Communities
在加纳，矿区当地社区认为社区发展是企业社会责任的最重要方面，以至于社区发展往往被认为是矿业公司的法定责任。因此，当地社区要求对社区发展作出越来越多的贡献，有时费用高得令人望而却步。矿业公司无法满足所有的需求，往往导致矿业公司与其东道社区之间的不良关系，从而对采矿业务产生不利影响。这构成了一种商业风险，需要通过从早先为社区发展提供自愿捐款的做法转变为使可持续社区发展成为采矿业务的组成部分来适当处理。本文介绍了Golden Star (Bogoso/Prestea) Limited (GSBPL)多年来用于管理其Bogoso/Prestea矿区当地社区(BPMLC)发展的具有不同原则和行动计划的进化战略模型，从糟糕的慈善社区援助模式(PCAM)到改进但无效的社区驱动援助模式(CDAM)，最终到目前有效，成功的企业社会责任协议模式(CSRAM)。该文件亦着重介绍了从制定《国家战略准则》的谈判过程中汲取的经验教训，以及实施该准则所带来的好处和成功，以及所面临的挑战。结论是，相互理解、宽容、透明、信任、承诺和问责是成功管理企业社会责任和社区发展的关键。关键词:社会责任，协议模式，矿业社区
{"title":"Corporate Social Responsibility Agreements Model for Community Development: The Case of Golden Star (Bogoso/Prestea) Limited and its Mine Local Community*","authors":"D. Mireku-Gyimah, R. Gyamfi","doi":"10.4314/GM.V16I1.12","DOIUrl":"https://doi.org/10.4314/GM.V16I1.12","url":null,"abstract":"In Ghana, community development is regarded by mine local communities as the most important aspect of Corporate Social Responsibility (CSR), to the extent that often community development is perceived to be a statutory responsibility of mining companies. Consequently, mine local communities demand for more and more, sometimes prohibitively expensive, contributions towards community development. The inability of mining companies to meet all the demands often leads to unsavoury relation between mining companies and their host communities with concomitant adverse effect on mining operations. This constitutes a business risk that needs to be addressed properly by shifting from the earlier practices of making voluntary contributions towards community development to making sustainable community development an integral part of the mining business. This paper presents the evolutionary strategic models, with differing principles and action plans, used by Golden Star (Bogoso/Prestea) Limited (GSBPL) over the years to manage the development of its Bogoso/Prestea Mine Local Community (BPMLC), videlicet from a poor Philanthropic Community Assistance Model (PCAM) to an improved but ineffective Community Driven Assistance Model (CDAM) and eventually to the current effective, successful CSR Agreements Model (CSRAM). The paper also highlights the lessons learnt from the negotiation process that led to formulation of the CSRAM as well as the benefits and successes resulting from its implementation and the challenges. It is concluded that mutual understanding, tolerance, transparency, trust, commitment and accountability are key to the successful management of CSR and community development. Keywords : Social Responsibility, Agreements Model, Mining Communities","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":"30 1","pages":"96-105"},"PeriodicalIF":0.0,"publicationDate":"2016-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82026838","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The usefulness of any geographic data depends on its fitness for a particular purpose. The critical measure of that fitness is referred to as data quality. Data quality may be expressed in terms of several indicators such as attributes, temporal or positional accuracies. In this research, positional accuracy assessment was carried out on two datasets using Root Mean Square Error (RMSE) technique. Coordinates of nineteen ground controls points were measured in the field using Differential Global Positioning System technique which served as a reference base. The coordinates of these points were compared with their corresponding positions extracted from the two datasets, Town Sheet (1: 2500) and orthophoto (1: 5000). The Town Sheet was scanned, rescaled (1:5000) and georeferenced in Ghana Meter Grid coordinate system to conform to the orthophoto. The digitised Town Sheet and the reference base were superimposed with the orthophoto serving as backdrop in GIS environment. Positional error of 1.23 m was obtained for points extracted from the Town Sheet, while an error of 2.79 m was registered for points from the orthophoto. Shoreline features extracted from these two datasets and appended for shoreline change analysis recorded a total positional error of 3.98 m. The study has shown that the original scale (large) of the Town Sheet may have contributed significantly to the quality of data extracted. In the orthophoto, though geometrically rectified, the scale representation of a unit measure on the photo explains the uncertainties in the dataset. The integrated dataset obviously bore the cumulative effect of the input datasets. It is concluded that for the purpose of shoreline change analysis, such as shoreline change trends, large scale data sources should be used where possible for accurate decision-making. It is recommended that the positional accuracy of any spatial data be ascertained before using it to support decision. Keywords : Positional Accuracy, Shoreline Change, Differential GPS, Root Mean Squared Error, Orthophoto
{"title":"Positional Accuracy Assessment for Effective Shoreline Change Analyses","authors":"C. B. Boye","doi":"10.4314/GM.V16I1.1","DOIUrl":"https://doi.org/10.4314/GM.V16I1.1","url":null,"abstract":"The usefulness of any geographic data depends on its fitness for a particular purpose. The critical measure of that fitness is referred to as data quality. Data quality may be expressed in terms of several indicators such as attributes, temporal or positional accuracies. In this research, positional accuracy assessment was carried out on two datasets using Root Mean Square Error (RMSE) technique. Coordinates of nineteen ground controls points were measured in the field using Differential Global Positioning System technique which served as a reference base. The coordinates of these points were compared with their corresponding positions extracted from the two datasets, Town Sheet (1: 2500) and orthophoto (1: 5000). The Town Sheet was scanned, rescaled (1:5000) and georeferenced in Ghana Meter Grid coordinate system to conform to the orthophoto. The digitised Town Sheet and the reference base were superimposed with the orthophoto serving as backdrop in GIS environment. Positional error of 1.23 m was obtained for points extracted from the Town Sheet, while an error of 2.79 m was registered for points from the orthophoto. Shoreline features extracted from these two datasets and appended for shoreline change analysis recorded a total positional error of 3.98 m. The study has shown that the original scale (large) of the Town Sheet may have contributed significantly to the quality of data extracted. In the orthophoto, though geometrically rectified, the scale representation of a unit measure on the photo explains the uncertainties in the dataset. The integrated dataset obviously bore the cumulative effect of the input datasets. It is concluded that for the purpose of shoreline change analysis, such as shoreline change trends, large scale data sources should be used where possible for accurate decision-making. It is recommended that the positional accuracy of any spatial data be ascertained before using it to support decision. Keywords : Positional Accuracy, Shoreline Change, Differential GPS, Root Mean Squared Error, Orthophoto","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":"12 5 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2016-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79890581","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Post-mining reclamation is aimed at restoring the productive capacity of the disturbed land and ensuring socio-economic and environmental sustainability. Methods that have been employed for the reclamation activity are reported in the literature. This paper studied the utility of certain plant species in Ghana for remediating mine degraded soils. The roots, stalks and leaves of the plant species were analysed for heavy metal accumulation. It was found that Xylopia aethiopica (Hwentia), Pityrogramma calomelanos (Fern), Chromolaena odorata (Acheampong weed), Leucaena leucocephala (Leucaena), and Terminalia superba (Ofram) have accumulated significant concentrations of the heavy metals and are highly suitable for cleaning copper, cadmium, lead, manganese and iron contaminated sites. Food and cash crops, Colocasia esculenta (Cocoyam), Musa sapientum (Banana), and Theobroma cacao (Cocoa) were also observed to have high uptake potential of the heavy metals. Thus, these crops are not recommended on rehabilitated polluted soils until such soils are rid of the contaminants to acceptable levels to mitigate potential concerns by consumers, because local indigenes and the community consume the leaves and tubers of Colocasia esculenta , the beans of Theobroma cacao and the fruits of Musa sapientum . Keywords : Phytoremediation, Bioremediation, Contaminated Soils, Degraded Soils, Heavy Metal
{"title":"Phytoremediation Potential of Plants Grown on Reclaimed Spoil Lands","authors":"K. J. Bansah, W. Addo","doi":"10.4314/GM.V16I1.8","DOIUrl":"https://doi.org/10.4314/GM.V16I1.8","url":null,"abstract":"Post-mining reclamation is aimed at restoring the productive capacity of the disturbed land and ensuring socio-economic and environmental sustainability. Methods that have been employed for the reclamation activity are reported in the literature. This paper studied the utility of certain plant species in Ghana for remediating mine degraded soils. The roots, stalks and leaves of the plant species were analysed for heavy metal accumulation. It was found that Xylopia aethiopica (Hwentia), Pityrogramma calomelanos (Fern), Chromolaena odorata (Acheampong weed), Leucaena leucocephala (Leucaena), and Terminalia superba (Ofram) have accumulated significant concentrations of the heavy metals and are highly suitable for cleaning copper, cadmium, lead, manganese and iron contaminated sites. Food and cash crops, Colocasia esculenta (Cocoyam), Musa sapientum (Banana), and Theobroma cacao (Cocoa) were also observed to have high uptake potential of the heavy metals. Thus, these crops are not recommended on rehabilitated polluted soils until such soils are rid of the contaminants to acceptable levels to mitigate potential concerns by consumers, because local indigenes and the community consume the leaves and tubers of Colocasia esculenta , the beans of Theobroma cacao and the fruits of Musa sapientum . Keywords : Phytoremediation, Bioremediation, Contaminated Soils, Degraded Soils, Heavy Metal","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":"22 1","pages":"68-75"},"PeriodicalIF":0.0,"publicationDate":"2016-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88962921","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mine production forecast is pertinent to mining as it serves production goals for a production period. Perseus Mining Ghana Limited (PMGL), Ayanfuri, deterministically forecasts mine production which sometimes result in significant variation from the actual production. This paper developed an innovative stochastic discrete event simulation model to predict production for two excavators at a pit in PMGL site using Arena ® Software. Time and motion studies of the shovel-truck system were conducted to build the stochastic model and production was predicted for four weeks. The results showed a total average production of 210 414.86 BCM ± 3 301.59 BCM at 95% confidence interval. The total average production reflected a variance of 2.34% from the actual production of 215 341 BCM. The deviation was low as compared to the deterministic planned production variance which was 5.44%. Keywords : Stochastic, Simulation, Deterministic, Production Forecast
{"title":"Application of Discrete Event Simulation in Mine Production Forecast","authors":"F. Kaba, V. Temeng, P. Eshun","doi":"10.4314/GM.V16I1.5","DOIUrl":"https://doi.org/10.4314/GM.V16I1.5","url":null,"abstract":"Mine production forecast is pertinent to mining as it serves production goals for a production period. Perseus Mining Ghana Limited (PMGL), Ayanfuri, deterministically forecasts mine production which sometimes result in significant variation from the actual production. This paper developed an innovative stochastic discrete event simulation model to predict production for two excavators at a pit in PMGL site using Arena ® Software. Time and motion studies of the shovel-truck system were conducted to build the stochastic model and production was predicted for four weeks. The results showed a total average production of 210 414.86 BCM ± 3 301.59 BCM at 95% confidence interval. The total average production reflected a variance of 2.34% from the actual production of 215 341 BCM. The deviation was low as compared to the deterministic planned production variance which was 5.44%. Keywords : Stochastic, Simulation, Deterministic, Production Forecast","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":"84 6 1","pages":"40-48"},"PeriodicalIF":0.0,"publicationDate":"2016-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77187718","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this study, we explore the causal influence of export earnings of cocoa towards economic growth (i.e., gross domestic product (GDP)). The augmented Dickey–Fuller (ADF) and the Phillips–Perron (PP) unit root tests indicate that the two series are integrated of order one, I (1). The results of the trace and the maxi-eigenvalue cointegration test based on Johansen’s procedure indicate the existence of a cointegration between export earnings of cocoa and GDP. Thus, the two variables of the study have a long-run equilibrium relationship. The vector error correction model of order two, VECM (2), was considered as the “best” model after evaluating other competing models. It is observed that, in the long-run, previous year export earnings of cocoa is positively related to economic growth. In the short run, the results revealed that the previous GDP has positive effect on current GDP; and higher export earnings of cocoa have positive effect on GDP. Feedback causality is observed between economic growth (GDP) and export earnings of cocoa. This suggests a bi-directional causality from export earnings to economic growth (GDP). Keywords : Cointegration, VECM, Johansen, ADF, Causality.
{"title":"Testing for Long-Run Relation between Economic Growth and Export Earnings of Cocoa in Ghana using Co-Integration Techniques","authors":"S. Twumasi-Ankrah, E. N. Wiah","doi":"10.4314/GM.V16I1.11","DOIUrl":"https://doi.org/10.4314/GM.V16I1.11","url":null,"abstract":"In this study, we explore the causal influence of export earnings of cocoa towards economic growth (i.e., gross domestic product (GDP)). The augmented Dickey–Fuller (ADF) and the Phillips–Perron (PP) unit root tests indicate that the two series are integrated of order one, I (1). The results of the trace and the maxi-eigenvalue cointegration test based on Johansen’s procedure indicate the existence of a cointegration between export earnings of cocoa and GDP. Thus, the two variables of the study have a long-run equilibrium relationship. The vector error correction model of order two, VECM (2), was considered as the “best” model after evaluating other competing models. It is observed that, in the long-run, previous year export earnings of cocoa is positively related to economic growth. In the short run, the results revealed that the previous GDP has positive effect on current GDP; and higher export earnings of cocoa have positive effect on GDP. Feedback causality is observed between economic growth (GDP) and export earnings of cocoa. This suggests a bi-directional causality from export earnings to economic growth (GDP). Keywords : Cointegration, VECM, Johansen, ADF, Causality.","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":"1 1","pages":"89-95"},"PeriodicalIF":0.0,"publicationDate":"2016-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90448303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Recent energy crisis in Ghana has led to an intense search for an alternate energy solution. Currently the country is relying on fossil fuel for electricity generation. About 43% of energy generated in the country is from fossil fuel thermal energy. In the event of shortages in petroleum products, these power plants will have to shut down or run on a low capacity resulting in load shedding routines. In order to explore an alternate energy source, the National Renewable Energy Laboratory (NREL) conducted a study to assess Ghana’s wind energy potential. Some areas across the country were found to have enough wind resource for power generation. However, sites for wind farms are not wind speed dependent only; other underlying factors also play an important role in the site selection process. The objectives of this research work are to identify these factors and integrate them in the site selection process within a GIS environment. The site selection was based on two major kinds of criteria setting; the constraints and factor criteria. Layers of these criteria setting were combined using the overlay function in a GIS environment. Weights were also assigned to the factor criteria layers using pairwise comparisons. Suitable sites were selected in five regions after incorporating the various criteria. A total of 142 isolated sites were selected after incorporating a number of factors and constraints. The optimal arrangement of the turbines for the Oforikrom site was also designed. This research recommends that the existing land use and ownership of the selected sites should be ascertained. Wind speed measuring masts should also be erected at the various sites to determine the economic viability of setting up a commercial wind farm. Keywords : Wind Energy, Wind Farm, GIS, Criteria
{"title":"Selecting Suitable Sites for Wind Energy Development in Ghana","authors":"P. Baffoe, D. Sarpong","doi":"10.4314/GM.V16I1.2","DOIUrl":"https://doi.org/10.4314/GM.V16I1.2","url":null,"abstract":"Recent energy crisis in Ghana has led to an intense search for an alternate energy solution. Currently the country is relying on fossil fuel for electricity generation. About 43% of energy generated in the country is from fossil fuel thermal energy. In the event of shortages in petroleum products, these power plants will have to shut down or run on a low capacity resulting in load shedding routines. In order to explore an alternate energy source, the National Renewable Energy Laboratory (NREL) conducted a study to assess Ghana’s wind energy potential. Some areas across the country were found to have enough wind resource for power generation. However, sites for wind farms are not wind speed dependent only; other underlying factors also play an important role in the site selection process. The objectives of this research work are to identify these factors and integrate them in the site selection process within a GIS environment. The site selection was based on two major kinds of criteria setting; the constraints and factor criteria. Layers of these criteria setting were combined using the overlay function in a GIS environment. Weights were also assigned to the factor criteria layers using pairwise comparisons. Suitable sites were selected in five regions after incorporating the various criteria. A total of 142 isolated sites were selected after incorporating a number of factors and constraints. The optimal arrangement of the turbines for the Oforikrom site was also designed. This research recommends that the existing land use and ownership of the selected sites should be ascertained. Wind speed measuring masts should also be erected at the various sites to determine the economic viability of setting up a commercial wind farm. Keywords : Wind Energy, Wind Farm, GIS, Criteria","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":"21 1","pages":"8-20"},"PeriodicalIF":0.0,"publicationDate":"2016-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78859672","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Forecariah Guinea Mine SA (FGMSA) in Guinea - Conakry mines and processes Iron ore. About 0.5 Mt of tailings material has already been generated with additional 4000 tons generated daily. This paper presents a re-treatment technology for the Iron tailings obtained from the processing plant of FGMSA. Metallurgical tests were carried out on the tailings to determine which process route gives the most satisfactory result in terms of recovery and cost. Two representative samples (FCOPD-01 and FCDOP-02), taking from the tailings, were investigated. Particle Size Distribution (PSD) and chemical composition of various size fractions of representative samples of the tailings were performed. Dense Medium Separation (DMS) and Magnetic Separation (WHIMS) were also performed on a number of size fractions. The initial chemical composition of the various size fractions shows that the highest Fe grades were present in the +1 mm fractions at 58.8% and 58.6% for FCOPD-01 and FCOPD-02 respectively. The PSD of the tailings also indicated a mass yield of 77.9% for the +1 mm fraction and 22.1% for the -1 mm fraction. Contaminant Oxides, such as Al 2 O 3 and SiO 2 tend to be higher in the finer size fractions (-1 mm) of both samples. Result from the DMS analysis performed on the (-4 +0.5) mm fraction shows an underflow mass yields of 45.98% with Fe grade of 65.55% and overflow mass yield of 53.08% with Fe grade of just 13.5%. Magnetic separation (WHIMS) results on the (-4 +0.5) mm samples also gave varied mass yield and Fe grade at different magnetic intensities (3000 Gauss, 6000 Gauss and 10,000 Gauss). However, the highest Fe mass yield and grade produced from the magnetic separation were 18.10% and 50.8% respectively. The results show that DMS technique has the potential to re-treat the tailings at FGMSA. Keywords : Treatment, Iron ore, Tailings, Magnetic separation, Dense Medium Separation
{"title":"Treatment of Iron Tailings at the Forecariah Guinea Mine - Guinea Conakry","authors":"A. Kali, W. Buah","doi":"10.4314/GM.V16I1.10","DOIUrl":"https://doi.org/10.4314/GM.V16I1.10","url":null,"abstract":"Forecariah Guinea Mine SA (FGMSA) in Guinea - Conakry mines and processes Iron ore. About 0.5 Mt of tailings material has already been generated with additional 4000 tons generated daily. This paper presents a re-treatment technology for the Iron tailings obtained from the processing plant of FGMSA. Metallurgical tests were carried out on the tailings to determine which process route gives the most satisfactory result in terms of recovery and cost. Two representative samples (FCOPD-01 and FCDOP-02), taking from the tailings, were investigated. Particle Size Distribution (PSD) and chemical composition of various size fractions of representative samples of the tailings were performed. Dense Medium Separation (DMS) and Magnetic Separation (WHIMS) were also performed on a number of size fractions. The initial chemical composition of the various size fractions shows that the highest Fe grades were present in the +1 mm fractions at 58.8% and 58.6% for FCOPD-01 and FCOPD-02 respectively. The PSD of the tailings also indicated a mass yield of 77.9% for the +1 mm fraction and 22.1% for the -1 mm fraction. Contaminant Oxides, such as Al 2 O 3 and SiO 2 tend to be higher in the finer size fractions (-1 mm) of both samples. Result from the DMS analysis performed on the (-4 +0.5) mm fraction shows an underflow mass yields of 45.98% with Fe grade of 65.55% and overflow mass yield of 53.08% with Fe grade of just 13.5%. Magnetic separation (WHIMS) results on the (-4 +0.5) mm samples also gave varied mass yield and Fe grade at different magnetic intensities (3000 Gauss, 6000 Gauss and 10,000 Gauss). However, the highest Fe mass yield and grade produced from the magnetic separation were 18.10% and 50.8% respectively. The results show that DMS technique has the potential to re-treat the tailings at FGMSA. Keywords : Treatment, Iron ore, Tailings, Magnetic separation, Dense Medium Separation","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":"37 1","pages":"83-88"},"PeriodicalIF":0.0,"publicationDate":"2016-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80106853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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