E. A. A. Kwesi, O. Simpson, J. K. Lawerty, A. Mends, C. Assencher, P. Baffoe
Boundary resurveys have become necessary in most mining communities of Ghana, especially, Tarkwa and its environs due to pressure and alteration in land use and land cover by mining operations. Most of the boundary markers (pillars, trees, streams, hills, valleys, footpaths, etc.) used in the past have been destroyed by mining and other associated activities. This has led to many disputes about ground boundaries and ownership of land tracts in the area. To curb the incidences of such conflicts, it has become important to have more reliable and scientific demarcations and surveys of the old boundaries and owners of land tracts in the area for registration, using modern technologies in land surveying. Equipment and methods used over a century ago to mark and describe land boundaries in the area have become obsolete now, and modern equipment and methods, while capable of measuring to very high precisions, cannot automatically give or tell the right boundaries and owners of land tracts established centuries ago. This paper examines the land boundaries situation in the study area, the impacts of mining on this, the need for boundary retracement surveys, the challenges that the rampant destruction of boundary markers in mining communities pose to such resurveys, and offers suggestions on dealing with these challenges in the management of land in the area. It also provides helpful information to land owners, land ‘buyers’ and land surveyors on the effects of the boundary problems on land transactions, surveys and registration in mining areas. Keywords: Surface Mining, Boundary Markers, Retracement Surveys, Land Conflicts, Management
{"title":"Land Management Problems in the Mining Communities of Tarkwa, Ghana -A Look at Boundary Markers and Resurveys","authors":"E. A. A. Kwesi, O. Simpson, J. K. Lawerty, A. Mends, C. Assencher, P. Baffoe","doi":"10.4314/gm.v21i1.2","DOIUrl":"https://doi.org/10.4314/gm.v21i1.2","url":null,"abstract":"Boundary resurveys have become necessary in most mining communities of Ghana, especially, Tarkwa and its environs due to pressure and alteration in land use and land cover by mining operations. Most of the boundary markers (pillars, trees, streams, hills, valleys, footpaths, etc.) used in the past have been destroyed by mining and other associated activities. This has led to many disputes about ground boundaries and ownership of land tracts in the area. To curb the incidences of such conflicts, it has become important to have more reliable and scientific demarcations and surveys of the old boundaries and owners of land tracts in the area for registration, using modern technologies in land surveying. Equipment and methods used over a century ago to mark and describe land boundaries in the area have become obsolete now, and modern equipment and methods, while capable of measuring to very high precisions, cannot automatically give or tell the right boundaries and owners of land tracts established centuries ago. This paper examines the land boundaries situation in the study area, the impacts of mining on this, the need for boundary retracement surveys, the challenges that the rampant destruction of boundary markers in mining communities pose to such resurveys, and offers suggestions on dealing with these challenges in the management of land in the area. It also provides helpful information to land owners, land ‘buyers’ and land surveyors on the effects of the boundary problems on land transactions, surveys and registration in mining areas. \u0000 \u0000Keywords: Surface Mining, Boundary Markers, Retracement Surveys, Land Conflicts, Management","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74226450","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 dramatic increase in hydrometallurgical extraction of gold from arsenic bearing gold ores has inevitably resulted in the release of arsenic into the environment worldwide. Residual arsenic minerals in tailings storage facilities can be oxidised and mobilise arsenic into the environment. This can contaminate soils, ground and surface waters and eventually biota. In spite of well-established technologies and recent advances in arsenic remediation, there are limited knowledge and understanding of the iron oxide substrate (goethite, hematite and magnetite) mineralogy and the fate of arsenic on the surface charge of these iron oxide substrates in an aqueous media during adsorption. The aim of the present study was to investigate the influence of interfacial chemistry on arsenic adsorption onto selected iron oxide particles to assist in developing a better understanding and new knowledge in arsenic removal from contaminated waters. Bulk mineralogy and partial chemical composition of selected iron oxide minerals were obtained using quantitative x-ray diffractometry (QXRD) and acid digestion followed by metal determination using inductively coupled plasma optical emission spectrometry (ICP-OES) respectively. Zeta Potential measurements involving iron oxide particles as arsenic adsorbents were carried out to elucidate the influence of interfacial chemistry on the adsorption behavior of arsenic from solution. The study confirmed that the iron oxide minerals were predominantly hematite, magnetite and goethite with goethite containing significant amounts of quartz. Arsenic adsorption was pH dependent and strongly influenced the zeta potential and isoelectric point (IEP) of the iron oxide particles. The zeta potential of all substrates studied was strongly positive at pH 2 but indicated a reversal at pH ~ > 9. The interaction between substrates, arsenic and its hydrolysable products resulted in significant decrease in the magnitude of zeta potential and change in IEP indicating specific adsorption. Keywords: Arsenic, Adsorption, Iron Oxide Minerals, Zeta Potential
{"title":"Arsenic Adsorption by Some Iron Oxide Minerals: Influence of Interfacial Chemistry","authors":"B. Koomson, E. Asiam","doi":"10.4314/GM.V20I2.6","DOIUrl":"https://doi.org/10.4314/GM.V20I2.6","url":null,"abstract":"The dramatic increase in hydrometallurgical extraction of gold from arsenic bearing gold ores has inevitably resulted in the release of arsenic into the environment worldwide. Residual arsenic minerals in tailings storage facilities can be oxidised and mobilise arsenic into the environment. This can contaminate soils, ground and surface waters and eventually biota. In spite of well-established technologies and recent advances in arsenic remediation, there are limited knowledge and understanding of the iron oxide substrate (goethite, hematite and magnetite) mineralogy and the fate of arsenic on the surface charge of these iron oxide substrates in an aqueous media during adsorption. The aim of the present study was to investigate the influence of interfacial chemistry on arsenic adsorption onto selected iron oxide particles to assist in developing a better understanding and new knowledge in arsenic removal from contaminated waters. Bulk mineralogy and partial chemical composition of selected iron oxide minerals were obtained using quantitative x-ray diffractometry (QXRD) and acid digestion followed by metal determination using inductively coupled plasma optical emission spectrometry (ICP-OES) respectively. Zeta Potential measurements involving iron oxide particles as arsenic adsorbents were carried out to elucidate the influence of interfacial chemistry on the adsorption behavior of arsenic from solution. The study confirmed that the iron oxide minerals were predominantly hematite, magnetite and goethite with goethite containing significant amounts of quartz. Arsenic adsorption was pH dependent and strongly influenced the zeta potential and isoelectric point (IEP) of the iron oxide particles. The zeta potential of all substrates studied was strongly positive at pH 2 but indicated a reversal at pH ~ > 9. The interaction between substrates, arsenic and its hydrolysable products resulted in significant decrease in the magnitude of zeta potential and change in IEP indicating specific adsorption. \u0000 \u0000Keywords: Arsenic, Adsorption, Iron Oxide Minerals, Zeta Potential","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":"17 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73239166","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}
This study seeks to evaluate the hydrogeochemical characteristics of water in the Tarkwa mining area using the Piper and Chadha plots and to carry out a health risk assessment using the US Environmental Protection Agency (USEPA) health risk assessment model. A total of 39 groundwater sample points were used for this study. Results from the Piper and Chadha diagrams show that the dominant water types in the study area are Ca-HCO3 and Mixed Ca-Mg-Cl water types which indicates that groundwater in the area can be classified as fresh water. The hazard quotient (HQ) value for heavy metals estimated, suggested an acceptable level of noncarcinogenic inimical health risk. In relation to the HQ value, the Hazard Index (HQ) calculated was less than 1 suggesting that inhabitants will not be exposed to a potential health risk for the injection of heavy metals. Carcinogenic risk estimated for As (1.80×10-4) was higher than the acceptable risk. The carcinogenic risk estimated therefore indicated that, drinking of groundwater over a long period will increase the probability of cancer. It can be concluded that currently the groundwater in the Tarkwa area is safe for domestic purposes. Keywords: Hydrochemical Characteristics, Human Risk Assessment, Tarkwa Mining Area
{"title":"Assessment of Groundwater Quality and Health Risk of Heavy Metals: A study from the Tarkwa Mining Area, Ghana","authors":"J. Seidu, A. Ewusi","doi":"10.4314/GM.V20I2.1","DOIUrl":"https://doi.org/10.4314/GM.V20I2.1","url":null,"abstract":"This study seeks to evaluate the hydrogeochemical characteristics of water in the Tarkwa mining area using the Piper and Chadha plots and to carry out a health risk assessment using the US Environmental Protection Agency (USEPA) health risk assessment model. A total of 39 groundwater sample points were used for this study. Results from the Piper and Chadha diagrams show that the dominant water types in the study area are Ca-HCO3 and Mixed Ca-Mg-Cl water types which indicates that groundwater in the area can be classified as fresh water. The hazard quotient (HQ) value for heavy metals estimated, suggested an acceptable level of noncarcinogenic inimical health risk. In relation to the HQ value, the Hazard Index (HQ) calculated was less than 1 suggesting that inhabitants will not be exposed to a potential health risk for the injection of heavy metals. Carcinogenic risk estimated for As (1.80×10-4) was higher than the acceptable risk. The carcinogenic risk estimated therefore indicated that, drinking of groundwater over a long period will increase the probability of cancer. It can be concluded that currently the groundwater in the Tarkwa area is safe for domestic purposes. \u0000 \u0000Keywords: Hydrochemical Characteristics, Human Risk Assessment, Tarkwa Mining Area","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74184369","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 an attempt to incorporate human factors into technical failures as accident causal factors, researchers have promoted the concept of human factor analysis. Human factor analysis models seek to identify latent conditions within the system that influence the operator’s action to trigger an accident. For an effective application of human factor analysis models, a domain-specific model is recommended. Most existing models are developed with category/subcategory peculiar to a particular domain. This presents challenges and hinders effective application outside the domain developed for. This paper sought to propose a human factor analysis framework for Ghana’s mining industry. A comparative study was carried out between three dominated accident causation models and investigation methods in literature; AcciMap, HFACS, and STAMP. The comparative assessment showed that HFACS is suitable for incident data analysis based on the following reason; ease of learning and use, suitability for multiple incident analysis and statistical quantification of trends and patterns, and high inter and intra-coder reliability. A thorough study was done on HFACS and its derivative. Based on recommendations and research findings on HFACS from literature, Human Factor Analysis, and Classification System – Ghana Mining Industry (HFACS-GMI) was proposed. The HFACS-GMI has 4 tiers, namely; External influence/factor, Organisational factor, Local Workplace/Individual Condition and, Unsafe Act. A partial list of causal factors under each tier was generated to serve as a guide during incident coding and investigation. The HFACS-GMI consists of 18 subcategories and these have been discussed. The HFACS-GMI is specific to the Ghanaian Mines and could potentially help in identifying causal and contributing factors of an accident during an incident investigation and data analysis. Keywords: Human Factor Analysis, Causal Factor, Causation Model, Mining Industry
{"title":"Human Factor Analysis Framework for Ghana’s Mining Industry","authors":"T. Joe-asare, N. Amegbey, E. Stemn","doi":"10.4314/GM.V20I2.8","DOIUrl":"https://doi.org/10.4314/GM.V20I2.8","url":null,"abstract":"In an attempt to incorporate human factors into technical failures as accident causal factors, researchers have promoted the concept of human factor analysis. Human factor analysis models seek to identify latent conditions within the system that influence the operator’s action to trigger an accident. For an effective application of human factor analysis models, a domain-specific model is recommended. Most existing models are developed with category/subcategory peculiar to a particular domain. This presents challenges and hinders effective application outside the domain developed for. This paper sought to propose a human factor analysis framework for Ghana’s mining industry. A comparative study was carried out between three dominated accident causation models and investigation methods in literature; AcciMap, HFACS, and STAMP. The comparative assessment showed that HFACS is suitable for incident data analysis based on the following reason; ease of learning and use, suitability for multiple incident analysis and statistical quantification of trends and patterns, and high inter and intra-coder reliability. A thorough study was done on HFACS and its derivative. Based on recommendations and research findings on HFACS from literature, Human Factor Analysis, and Classification System – Ghana Mining Industry (HFACS-GMI) was proposed. The HFACS-GMI has 4 tiers, namely; External influence/factor, Organisational factor, Local Workplace/Individual Condition and, Unsafe Act. A partial list of causal factors under each tier was generated to serve as a guide during incident coding and investigation. The HFACS-GMI consists of 18 subcategories and these have been discussed. The HFACS-GMI is specific to the Ghanaian Mines and could potentially help in identifying causal and contributing factors of an accident during an incident investigation and data analysis. \u0000 \u0000Keywords: Human Factor Analysis, Causal Factor, Causation Model, Mining Industry","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":"65 1","pages":"60-76"},"PeriodicalIF":0.0,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78588156","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}
Rehabilitation works were carried out on boreholes in the Dunkwa Mining town in the Central Region of Ghana. These works were carried out because the boreholes had lost their original yields due to clogging, corrosion and encrustation and had been abandoned for a long time. The cost of drilling a new well and assessing the productivity of the well is $4,500 which is more expensive that carrying out rehabilitation works which is cheaper, about $800. Also, the initial yields of the boreholes were very high according to the feasibility report which is not a common characteristic of the rocks in the area. Camera inspection followed by rehabilitation, pre and post pumping tests were carried out to assess whether there has been an improvement in their yield after the exercise and that the yield obtained will be adequate for a water supply design. Results show that all the boreholes had an improvement in their yields (57.19 - 259.80 %) after the rehabilitation. It can therefore be concluded that rehabilitation is effective in restoring boreholes to their original yields. Organisations drilling boreholes to communities can take advantage of rehabilitation of the existing boreholes located in the communities which are high yielding, thereby reducing project implementation cost. Keywords: Borehole Rehabilitation, Borehole Yields, Borehole Camera Inspection, Pumping Test
{"title":"Borehole Rehabilitation: A Case Study in the Dunkwa Mining Town","authors":"A. Ewusi, J. Seidu","doi":"10.4314/gm.v20i2.2","DOIUrl":"https://doi.org/10.4314/gm.v20i2.2","url":null,"abstract":"Rehabilitation works were carried out on boreholes in the Dunkwa Mining town in the Central Region of Ghana. These works were carried out because the boreholes had lost their original yields due to clogging, corrosion and encrustation and had been abandoned for a long time. The cost of drilling a new well and assessing the productivity of the well is $4,500 which is more expensive that carrying out rehabilitation works which is cheaper, about $800. Also, the initial yields of the boreholes were very high according to the feasibility report which is not a common characteristic of the rocks in the area. Camera inspection followed by rehabilitation, pre and post pumping tests were carried out to assess whether there has been an improvement in their yield after the exercise and that the yield obtained will be adequate for a water supply design. Results show that all the boreholes had an improvement in their yields (57.19 - 259.80 %) after the rehabilitation. It can therefore be concluded that rehabilitation is effective in restoring boreholes to their original yields. Organisations drilling boreholes to communities can take advantage of rehabilitation of the existing boreholes located in the communities which are high yielding, thereby reducing project implementation cost. \u0000Keywords: Borehole Rehabilitation, Borehole Yields, Borehole Camera Inspection, Pumping Test","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82447256","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}
Sediment contamination by heavy metals resulting from anthropogenic activities is increasingly becoming a global concern due to the risk it poses to human well-being and ecological integrity at large. The purpose of this study was to assess the heavy metals loading in sediment along the Kawere stream. Ten sediment samples were collected, acid digested and analysed for copper (Cu), lead (Pb), cadmium (Cd), manganese (Mn), zinc (Zn), nickel (Ni), chromium (Cr), cobalt (Co) and iron (Fe) using a Varian AA240FS Atomic Absorption Spectrometer (AAS). The Australian and New Zealand Environment and Conservation Council (ANZECC) guidelines for freshwater sediment quality was used as the benchmark against which the measured metal concentrations were compared. Nemerow’s pollution and potential ecological risk indices were used to evaluate the pollution status and ecological risk levels of the heavy metals in the stream. The results obtained indicated that, except Cu which exceeded the ANZECC trigger value of 65 mg/kg at three sampling sites (K01=171.29 mg/kg, K05=170.83 mg/kg and K07=113.31 mg/kg), all other measured heavy metals concentrations were below their corresponding ANZECC values. Heavy metal pollution assessment showed that three samples (K01, K05 and K07) were slightly polluted, suggesting the likelihood of posing a health threat to the aquatic organisms and humans. Calculated Ecological Risk Index (RI) ranged from 3.229 to 19.750 (RI < 150), representing a low ecological risk. As such, the metals, Cu, Ni, Cd, Pb, Cr, and Zn pose a low ecological risk to the aquatic ecosystem. Although the ecological risk is low based on the current results, constant monitoring of the stream quality is recommended due to the increasing human activities along the stream as well as the sediments ability to accumulate and remobilise heavy metals back into the water column and possibly transferring them through the food chain. Keywords: Heavy Metals, Sediment, Ecological Risk Assessment, Pollution, Stream
{"title":"Heavy Metal Loading in Surface Sediments along the Kawere Stream, Tarkwa, Ghana","authors":"S. Ndur, S. Y. Nyarko, I. Quaicoe, L. Osei","doi":"10.4314/GM.V20I2.9","DOIUrl":"https://doi.org/10.4314/GM.V20I2.9","url":null,"abstract":"Sediment contamination by heavy metals resulting from anthropogenic activities is increasingly becoming a global concern due to the risk it poses to human well-being and ecological integrity at large. The purpose of this study was to assess the heavy metals loading in sediment along the Kawere stream. Ten sediment samples were collected, acid digested and analysed for copper (Cu), lead (Pb), cadmium (Cd), manganese (Mn), zinc (Zn), nickel (Ni), chromium (Cr), cobalt (Co) and iron (Fe) using a Varian AA240FS Atomic Absorption Spectrometer (AAS). The Australian and New Zealand Environment and Conservation Council (ANZECC) guidelines for freshwater sediment quality was used as the benchmark against which the measured metal concentrations were compared. Nemerow’s pollution and potential ecological risk indices were used to evaluate the pollution status and ecological risk levels of the heavy metals in the stream. The results obtained indicated that, except Cu which exceeded the ANZECC trigger value of 65 mg/kg at three sampling sites (K01=171.29 mg/kg, K05=170.83 mg/kg and K07=113.31 mg/kg), all other measured heavy metals concentrations were below their corresponding ANZECC values. Heavy metal pollution assessment showed that three samples (K01, K05 and K07) were slightly polluted, suggesting the likelihood of posing a health threat to the aquatic organisms and humans. Calculated Ecological Risk Index (RI) ranged from 3.229 to 19.750 (RI < 150), representing a low ecological risk. As such, the metals, Cu, Ni, Cd, Pb, Cr, and Zn pose a low ecological risk to the aquatic ecosystem. Although the ecological risk is low based on the current results, constant monitoring of the stream quality is recommended due to the increasing human activities along the stream as well as the sediments ability to accumulate and remobilise heavy metals back into the water column and possibly transferring them through the food chain. \u0000 \u0000Keywords: Heavy Metals, Sediment, Ecological Risk Assessment, Pollution, Stream","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":"13 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81047956","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}
K. Nimako, A. Dwumfour, K. Mensah, P. Koshy, J. R. Dankwah
This research investigated the calcination behaviour of the Nsuta Rhodochrosite (MnCO3) in the presence and absence of end-of-life high density polyethylene (HDPE) using a custom-made palm kernel shell fired furnace. Samples of pulverised Nsuta rhodochrosite were heated rapidly for 30, 40, 50 and 60 minutes, coupled with temperature measurements to determine the maximum temperature attained in the fireclay crucible. The procedure at 60 min was repeated using three blends of rhodochrosite samples containing different masses of HDPE (30 g, 40 g and 50 g) and heated for an hour. For gas analyses studies during calcination, cylindrical compacts of rhodochrosite ore in a LECOTM crucible were heated rapidly with and without high density polyethylene (HDPE at C/O ratio = 1.0, 1.5, and 2.0) in a horizontal tube furnace for 600 s at 1150 °C under high purity argon gas and the off gas was continuously analysed for CH4, CO and CO2 using an online infrared gas analyser. The content of H2 in the off gas was detected using a GC3 gas chromatographic analyser equipped with a thermal conductivity detector. The Nsuta rhodochrosite ore was found to consist of a mixture of manganese II carbonate (MnCO3), silica (SiO2), mixed transition metal carbonate of the form Ca(Mn, Mg)(CO3)2 and mixed metal silicate of the form Ca0.6Mg1.94Si2O6. Calcination results indicated visible colour changes (from grey to dark brown), along with significant changes in the mass before and after calcination. In the absence and presence of the polymer, measured temperatures in the crucible ranged from 1001 °C to 1366 °C and 1361 °C to 1369 °C, respectively. Analyses by XRF showed marginal increase in the content of Mn in the calcined ore with HDPE addition. Gas analyses indicate that blending the carbonate with HDPE before heating results in significant decrease in the amount of CO2 emitted. Keywords: Land Tenure Security, Registration, Spatial Data, Attribute Data
{"title":"Calcination Behaviour of Nsuta Rhodochrosite Ore in the Presence and Absence of End-of-Life High Density Polyethylene","authors":"K. Nimako, A. Dwumfour, K. Mensah, P. Koshy, J. R. Dankwah","doi":"10.4314/gm.v20i2.4","DOIUrl":"https://doi.org/10.4314/gm.v20i2.4","url":null,"abstract":"This research investigated the calcination behaviour of the Nsuta Rhodochrosite (MnCO3) in the presence and absence of end-of-life high density polyethylene (HDPE) using a custom-made palm kernel shell fired furnace. Samples of pulverised Nsuta rhodochrosite were heated rapidly for 30, 40, 50 and 60 minutes, coupled with temperature measurements to determine the maximum temperature attained in the fireclay crucible. The procedure at 60 min was repeated using three blends of rhodochrosite samples containing different masses of HDPE (30 g, 40 g and 50 g) and heated for an hour. For gas analyses studies during calcination, cylindrical compacts of rhodochrosite ore in a LECOTM crucible were heated rapidly with and without high density polyethylene (HDPE at C/O ratio = 1.0, 1.5, and 2.0) in a horizontal tube furnace for 600 s at 1150 °C under high purity argon gas and the off gas was continuously analysed for CH4, CO and CO2 using an online infrared gas analyser. The content of H2 in the off gas was detected using a GC3 gas chromatographic analyser equipped with a thermal conductivity detector. The Nsuta rhodochrosite ore was found to consist of a mixture of manganese II carbonate (MnCO3), silica (SiO2), mixed transition metal carbonate of the form Ca(Mn, Mg)(CO3)2 and mixed metal silicate of the form Ca0.6Mg1.94Si2O6. Calcination results indicated visible colour changes (from grey to dark brown), along with significant changes in the mass before and after calcination. In the absence and presence of the polymer, measured temperatures in the crucible ranged from 1001 °C to 1366 °C and 1361 °C to 1369 °C, respectively. Analyses by XRF showed marginal increase in the content of Mn in the calcined ore with HDPE addition. Gas analyses indicate that blending the carbonate with HDPE before heating results in significant decrease in the amount of CO2 emitted. \u0000 \u0000Keywords: Land Tenure Security, Registration, Spatial Data, Attribute Data","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91165094","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}
Acid and Metalliferous Drainage (AMD) is recognised as serious environmental problem in the mining industry. This is because environmental issue of AMD poses serious threat to water quality, vegetation cover and social licence of the mining operations. AMD occurs when reactive sulphide bearing materials are exposed to oxidising conditions. It has now become imperative for some mining companies to test sulphide bearing minerals for their AMD potential before major mining excavations are done. This work determines the AMD potential of fifty (50) waste rock samples from a Mine using Acid Base Accounting (ABA) techniques. Mineralogical studies on the sample indicated that the major sulphide mineral assemblages present were pyrite, arsenopyrite and chalcopyrite. Paste pH showed that 20% of the samples had undergone weathering and as such AMD generation had already started. Approximately 22% of the sample had conductivity levels between 1000 to 10,000 µS/cm and this shows a typical AMD chemical characteristic of high salinity. Acid Base Accounting showed that 32% of the samples were acid generating. Exactly 16% were non-acid forming and 52% were uncertain. The analysis showed that the potential for AMD generation exists for the waste rock material and can affect the local environment, specifically water quality if preventive measures are not taken. Keywords: Sulphide, Waste Rock, Acid Base Accounting, Paste pH, Conductivity
{"title":"Determining Acid and Metalliferous Drainage Potential of Waste Rock on a Mine","authors":"S. Fosu, C. Owusu, F. Ntsiful, K. Ackah","doi":"10.4314/GM.V20I2.7","DOIUrl":"https://doi.org/10.4314/GM.V20I2.7","url":null,"abstract":"Acid and Metalliferous Drainage (AMD) is recognised as serious environmental problem in the mining industry. This is because environmental issue of AMD poses serious threat to water quality, vegetation cover and social licence of the mining operations. AMD occurs when reactive sulphide bearing materials are exposed to oxidising conditions. It has now become imperative for some mining companies to test sulphide bearing minerals for their AMD potential before major mining excavations are done. This work determines the AMD potential of fifty (50) waste rock samples from a Mine using Acid Base Accounting (ABA) techniques. Mineralogical studies on the sample indicated that the major sulphide mineral assemblages present were pyrite, arsenopyrite and chalcopyrite. Paste pH showed that 20% of the samples had undergone weathering and as such AMD generation had already started. Approximately 22% of the sample had conductivity levels between 1000 to 10,000 µS/cm and this shows a typical AMD chemical characteristic of high salinity. Acid Base Accounting showed that 32% of the samples were acid generating. Exactly 16% were non-acid forming and 52% were uncertain. The analysis showed that the potential for AMD generation exists for the waste rock material and can affect the local environment, specifically water quality if preventive measures are not taken. \u0000 \u0000Keywords: Sulphide, Waste Rock, Acid Base Accounting, Paste pH, Conductivity","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":"233 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84346497","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 consequences of collapsed stopes can be dire in the mining industry. This can lead to the revocation of a mining license in most jurisdictions, especially when the harm costs lives. Therefore, as a mine planning and technical services engineer, it is imperative to estimate the stability status of stopes. This study has attempted to produce a stope stability prediction model adopted from stability graph using ensemble learning techniques. This study was conducted using 472 case histories from 120 stopes of AngloGold Ashanti Ghana, Obuasi Mine. Random Forest, Gradient Boosting, Bootstrap Aggregating and Adaptive Boosting classification algorithms were used to produce the models. A comparative analysis was done using six classification performance metrics namely Accuracy, Precision, Sensitivity, F1-score, Specificity and Mathews Correlation Coefficient (MCC) to determine which ensemble learning technique performed best in predicting the stability of a stope. The Bootstrap Aggregating model obtained the highest MCC score of 96.84% while the Adaptive Boosting model obtained the lowest score. The Specificity scores in decreasing order of performance were 98.95%, 97.89%, 96.32% and 95.26% for Bootstrap Aggregating, Gradient Boosting, Random Forest and Adaptive Boosting respectively. The results showed equal Accuracy, Precision, F1-score and Sensitivity score of 97.89% for the Bootstrap Aggregating model while the same observation was made for Adaptive Boosting, Gradient Boosting and Random Forest with 90.53%, 92.63% and 95.79% scores respectively. At a 95% confidence interval using Wilson Score Interval, the results showed that the Bootstrap Aggregating model produced the minimal error and hence was selected as the alternative stope design tool for predicting the stability status of stopes. Keywords: Stope Stability, Ensemble Learning Techniques, Stability Graph, Machine Learning
{"title":"Development of a Stope Stability Prediction Model Using Ensemble Learning Techniques - A Case Study","authors":"F. Saadaari, D. Mireku-Gyimah, B. Olaleye","doi":"10.4314/gm.v20i2.3","DOIUrl":"https://doi.org/10.4314/gm.v20i2.3","url":null,"abstract":"The consequences of collapsed stopes can be dire in the mining industry. This can lead to the revocation of a mining license in most jurisdictions, especially when the harm costs lives. Therefore, as a mine planning and technical services engineer, it is imperative to estimate the stability status of stopes. This study has attempted to produce a stope stability prediction model adopted from stability graph using ensemble learning techniques. This study was conducted using 472 case histories from 120 stopes of AngloGold Ashanti Ghana, Obuasi Mine. Random Forest, Gradient Boosting, Bootstrap Aggregating and Adaptive Boosting classification algorithms were used to produce the models. A comparative analysis was done using six classification performance metrics namely Accuracy, Precision, Sensitivity, F1-score, Specificity and Mathews Correlation Coefficient (MCC) to determine which ensemble learning technique performed best in predicting the stability of a stope. The Bootstrap Aggregating model obtained the highest MCC score of 96.84% while the Adaptive Boosting model obtained the lowest score. The Specificity scores in decreasing order of performance were 98.95%, 97.89%, 96.32% and 95.26% for Bootstrap Aggregating, Gradient Boosting, Random Forest and Adaptive Boosting respectively. The results showed equal Accuracy, Precision, F1-score and Sensitivity score of 97.89% for the Bootstrap Aggregating model while the same observation was made for Adaptive Boosting, Gradient Boosting and Random Forest with 90.53%, 92.63% and 95.79% scores respectively. At a 95% confidence interval using Wilson Score Interval, the results showed that the Bootstrap Aggregating model produced the minimal error and hence was selected as the alternative stope design tool for predicting the stability status of stopes. \u0000 \u0000Keywords: Stope Stability, Ensemble Learning Techniques, Stability Graph, Machine Learning","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84114928","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}
Abstract The University of Mines and Technology (UMaT), Tarkwa, Ghana has a Local Area Network (LAN) infrastructure whose primary purpose is to facilitate research; teaching and learning; and information dissemination. The LAN infrastructure spans a maximum distance of 1.39 square-kilometers with an upload and download speed of 115 Mb/s and interconnects the administration block, faculties, library and halls of residence with high-speed ethernet links operating over a dedicated fiber optic backbone. The LAN infrastructure with connectivity to the internet impact operations in various sections of the University, notably, the University Library. The main purpose of the library is to interact with different information networks to make available e-resource materials to students, academic and non-academic staff. This can only be achieved over a dedicated LAN infrastructure. The introduction of Library Management Systems (Koha), Online Public Access Catalogue (OPAC) and the UMaT Space has improved library services such as document delivery, circulation and borrowing, amongst others. However, there exist a major challenge associated with library e-resources accessibility. This paper sought to investigate the factors hindering library e-resource accessibility for the purposes of improving research. Questionnaire was administered to respondents to solicit primary information while secondary information was obtained from published literature. 537 out of 855 participants responded to the questionnaire administered. 351 (65.36%) represented undergraduate students, 73 (13.60%) represented postgraduate students, 87 (16.20%), 21 (3.91%), 5 (0.93%) represented teaching, non-teaching and library staff respectively. The responses were analysed using simple tables and pie charts. Results from the study showed inadequate access points to enable users access these e-resource materials and lack of knowledge about the existence of these resources. The investigation further revealed the need for the library to embark on an information literacy drive for both students and academic staff. Various ways of improving e-resource accessibility was suggested. Keywords: Local Area Network, ICT Infrastructure, Online Public Access Catalogue (OPAC), E-Resources
{"title":"The Information and Communication Technology Infrastructure on University of Mines and Technology Campus and Its Impact on Library e-Resource Accessibility","authors":"P. Anafo, S. Akpah, Y. Ofori","doi":"10.4314/gm.v20i1.9","DOIUrl":"https://doi.org/10.4314/gm.v20i1.9","url":null,"abstract":"Abstract \u0000The University of Mines and Technology (UMaT), Tarkwa, Ghana has a Local Area Network (LAN) infrastructure whose primary purpose is to facilitate research; teaching and learning; and information dissemination. The LAN infrastructure spans a maximum distance of 1.39 square-kilometers with an upload and download speed of 115 Mb/s and interconnects the administration block, faculties, library and halls of residence with high-speed ethernet links operating over a dedicated fiber optic backbone. The LAN infrastructure with connectivity to the internet impact operations in various sections of the University, notably, the University Library. The main purpose of the library is to interact with different information networks to make available e-resource materials to students, academic and non-academic staff. This can only be achieved over a dedicated LAN infrastructure. The introduction of Library Management Systems (Koha), Online Public Access Catalogue (OPAC) and the UMaT Space has improved library services such as document delivery, circulation and borrowing, amongst others. However, there exist a major challenge associated with library e-resources accessibility. This paper sought to investigate the factors hindering library e-resource accessibility for the purposes of improving research. Questionnaire was administered to respondents to solicit primary information while secondary information was obtained from published literature. 537 out of 855 participants responded to the questionnaire administered. 351 (65.36%) represented undergraduate students, 73 (13.60%) represented postgraduate students, 87 (16.20%), 21 (3.91%), 5 (0.93%) represented teaching, non-teaching and library staff respectively. The responses were analysed using simple tables and pie charts. Results from the study showed inadequate access points to enable users access these e-resource materials and lack of knowledge about the existence of these resources. The investigation further revealed the need for the library to embark on an information literacy drive for both students and academic staff. Various ways of improving e-resource accessibility was suggested. \u0000 \u0000Keywords: Local Area Network, ICT Infrastructure, Online Public Access Catalogue (OPAC), E-Resources","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72806415","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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