Groundwater is an important resource in the Adansi mining area as some communities in the area are not connected to the Ghana national water network. These communities therefore utilise groundwater for potable water supply. The hydrogeological properties of an aquifer coupled with climatic conditions and geomorphology determines how much groundwater exists in that location. A hydrogeological study of the rocks in the Adansi area was carried out to obtain the aquifer hydraulic properties. Drilling and pumping test analysis information were used to assess these properties. The average borehole depth in the area was 44.3 m whilst the average static water level is 10.75 m. There is a general decrease in yield with an increase in borehole total depth. There is also no strong correlation between aquifer saturated thickness, yield and drawdown. Transmissivity of the aquifer decreases from the phyllite, argillitc sediments, granites to sandstone. Three hydrogeological regimes (> 0.9 m/day, 0.9 – 0.09 m/day and < 0.09 m/day) were also realised based on the hydraulic conductivity. The spatial distribution of the hydraulic properties suggests the influence of geological structures on the occurrence of groundwater in the area. Keywords : Hydrogeological Properties, Mining, Hydraulic, Drilling, Groundwater
{"title":"Hydrogeological Properties of the Rocks in Adansi Mining Area, Ghana","authors":"A. Asante-annor, A. Ewusi","doi":"10.4314/GM.V16I1.4","DOIUrl":"https://doi.org/10.4314/GM.V16I1.4","url":null,"abstract":"Groundwater is an important resource in the Adansi mining area as some communities in the area are not connected to the Ghana national water network. These communities therefore utilise groundwater for potable water supply. The hydrogeological properties of an aquifer coupled with climatic conditions and geomorphology determines how much groundwater exists in that location. A hydrogeological study of the rocks in the Adansi area was carried out to obtain the aquifer hydraulic properties. Drilling and pumping test analysis information were used to assess these properties. The average borehole depth in the area was 44.3 m whilst the average static water level is 10.75 m. There is a general decrease in yield with an increase in borehole total depth. There is also no strong correlation between aquifer saturated thickness, yield and drawdown. Transmissivity of the aquifer decreases from the phyllite, argillitc sediments, granites to sandstone. Three hydrogeological regimes (> 0.9 m/day, 0.9 – 0.09 m/day and < 0.09 m/day) were also realised based on the hydraulic conductivity. The spatial distribution of the hydraulic properties suggests the influence of geological structures on the occurrence of groundwater in the area. Keywords : Hydrogeological Properties, Mining, Hydraulic, Drilling, Groundwater","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75948095","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 Tarkwa Mine (TM) of Goldfields Ghana Limited (GGL) undertakes open pit mining operations with gold recovery by heap leach technology. As a mine, it is susceptible to health and safety risks in its operations. In spite of health and safety policy and regulations put in place at the TM, there have been reported cases of some job-related injuries, accidents and diseases among the employees. Could it be that the employees are not aware of the health and safety policy and regulations? To answer this question, this paper sought to examine the level of employees’ awareness of the health and safety policy and regulations, the suitability of the medium of information provision and the quality of information given to the employees on health and safety. The level of awareness of, and the suitability of the medium of information provision on, health and safety policy and regulations were assessed by analysing employees’ responses obtained from questionnaire administration while the quality of information was assessed using the content of information from internal newsletters, brochures, notices and sign boards. It was found that majority of the employees are very much aware of the health and safety policy and regulations because of good mode and medium of information provision. Various ways of improving information provision at the TM of GGL to reduce health and safety risks have been provided. Keywords : Information Provision, Awareness, Risk, Health and Safety Management
{"title":"Information Management of Health and Safety at the Tarkwa Mine of Goldfields Ghana Limited","authors":"Y. Ofori, Gloria Pomfowaa","doi":"10.4314/GM.V16I1.13","DOIUrl":"https://doi.org/10.4314/GM.V16I1.13","url":null,"abstract":"The Tarkwa Mine (TM) of Goldfields Ghana Limited (GGL) undertakes open pit mining operations with gold recovery by heap leach technology. As a mine, it is susceptible to health and safety risks in its operations. In spite of health and safety policy and regulations put in place at the TM, there have been reported cases of some job-related injuries, accidents and diseases among the employees. Could it be that the employees are not aware of the health and safety policy and regulations? To answer this question, this paper sought to examine the level of employees’ awareness of the health and safety policy and regulations, the suitability of the medium of information provision and the quality of information given to the employees on health and safety. The level of awareness of, and the suitability of the medium of information provision on, health and safety policy and regulations were assessed by analysing employees’ responses obtained from questionnaire administration while the quality of information was assessed using the content of information from internal newsletters, brochures, notices and sign boards. It was found that majority of the employees are very much aware of the health and safety policy and regulations because of good mode and medium of information provision. Various ways of improving information provision at the TM of GGL to reduce health and safety risks have been provided. Keywords : Information Provision, Awareness, Risk, Health and Safety Management","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77577493","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}
A. Ewusi, A. Asante-annor, J. Seidu, L. O. Fosu-Gyeabour
The assessment of groundwater vulnerability to contamination has become an important element for landuse planning and groundwater resource management. This study aims at estimating groundwater vulnerability using an integration of Geographic Information System (GIS) and DRASTIC method in the Kumasi Metropolitan Assembly (KMA). The groundwater vulnerability map was prepared using index and overlay analysis with the aid of Arc GIS 10. The DRASTIC Index (DI) computed ranged between 70 and 164 as the lowest and highest contamination potential respectively. The eastern and western flanks and north-west tip of KMA are underlain by the granites which bear water due to the combined effect of weathering and fracturing and are dominated by "Very High", "High" and "Moderate" vulnerability based on the vulnerability index computed. The "Low" and "Very Low" vulnerability are located at the northern, central and southern parts of KMA which are underlain by phyllites. These suggest that boreholes located in the Birimian metasedimentary units which comprise mainly phyllites would be less likely to be vulnerable to contamination than those located in the intrusive rocks dominated by the granites. Keywords : Groundwater Vulnerability, Soil Media, Hydraulic Conductivity, Overlay Analysis
{"title":"Groundwater Vulnerability Assessment using Drastic Index and GIS in Kumasi Metropolitan Assembly, Ghana.","authors":"A. Ewusi, A. Asante-annor, J. Seidu, L. O. Fosu-Gyeabour","doi":"10.4314/GM.V16I1.3","DOIUrl":"https://doi.org/10.4314/GM.V16I1.3","url":null,"abstract":"The assessment of groundwater vulnerability to contamination has become an important element for landuse planning and groundwater resource management. This study aims at estimating groundwater vulnerability using an integration of Geographic Information System (GIS) and DRASTIC method in the Kumasi Metropolitan Assembly (KMA). The groundwater vulnerability map was prepared using index and overlay analysis with the aid of Arc GIS 10. The DRASTIC Index (DI) computed ranged between 70 and 164 as the lowest and highest contamination potential respectively. The eastern and western flanks and north-west tip of KMA are underlain by the granites which bear water due to the combined effect of weathering and fracturing and are dominated by \"Very High\", \"High\" and \"Moderate\" vulnerability based on the vulnerability index computed. The \"Low\" and \"Very Low\" vulnerability are located at the northern, central and southern parts of KMA which are underlain by phyllites. These suggest that boreholes located in the Birimian metasedimentary units which comprise mainly phyllites would be less likely to be vulnerable to contamination than those located in the intrusive rocks dominated by the granites. Keywords : Groundwater Vulnerability, Soil Media, Hydraulic Conductivity, Overlay Analysis","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85695372","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}
Blast Movement Monitoring (BMM) system is a new method of determining material movement during blasting in order to minimise ore loss, dilution and sometimes misclassification. The BMM system was introduced at AngloGold Ashanti Iduapriem (AAIL) Mine in the first quarter of 2013 as a result of reconciliation challenges at the start of operation at the Ajopa Pit in the first quarter of 2012. Since the introduction, there has been improvement in reconciliation, but the cost implication became worth assessing because of dwindling gold price. The main objective of this paper, therefore, is to assess the benefits or otherwise of BMM system on blast induced movement at Iduapriem Mine. The study comprises data collection on BMM system at AAIL and its analysis, as well as cost and benefit analysis. From the BMM data analysis, it was observed that, the bottom flitch of the blasted material moved more than the top flitch in the horizontal direction while the reverse was the case for the vertical movement. The cost-benefit analysis from four shots analysed revealed that there was a benefit of $753 835 which translates into 650% return on investment. Thus, the use of the BMM system has positive financial impact on Iduapriem Mine. Continuous use of the system as a grade control practice has, therefore, been recommended for the Mine, especially with shots containing ore. Furthermore, a dedicated team for this task has been recommended to enhance efficiency. Finally, high precision GPS has been suggested to be added to the detector instrument to make surveying of pre-blast and post-blast BMM points easier and faster. Keywords : Blast Movement Monitoring System, Ore Loss, Dilution, Misclassification, Reconciliation
{"title":"Control of Ore Loss and Dilution at AngloGold Ashanti, Iduapriem Mine using Blast Movement Monitoring System","authors":"P. Eshun, Kwame Akorli Dzigbordi","doi":"10.4314/GM.V16I1.6","DOIUrl":"https://doi.org/10.4314/GM.V16I1.6","url":null,"abstract":"Blast Movement Monitoring (BMM) system is a new method of determining material movement during blasting in order to minimise ore loss, dilution and sometimes misclassification. The BMM system was introduced at AngloGold Ashanti Iduapriem (AAIL) Mine in the first quarter of 2013 as a result of reconciliation challenges at the start of operation at the Ajopa Pit in the first quarter of 2012. Since the introduction, there has been improvement in reconciliation, but the cost implication became worth assessing because of dwindling gold price. The main objective of this paper, therefore, is to assess the benefits or otherwise of BMM system on blast induced movement at Iduapriem Mine. The study comprises data collection on BMM system at AAIL and its analysis, as well as cost and benefit analysis. From the BMM data analysis, it was observed that, the bottom flitch of the blasted material moved more than the top flitch in the horizontal direction while the reverse was the case for the vertical movement. The cost-benefit analysis from four shots analysed revealed that there was a benefit of $753 835 which translates into 650% return on investment. Thus, the use of the BMM system has positive financial impact on Iduapriem Mine. Continuous use of the system as a grade control practice has, therefore, been recommended for the Mine, especially with shots containing ore. Furthermore, a dedicated team for this task has been recommended to enhance efficiency. Finally, high precision GPS has been suggested to be added to the detector instrument to make surveying of pre-blast and post-blast BMM points easier and faster. Keywords : Blast Movement Monitoring System, Ore Loss, Dilution, Misclassification, Reconciliation","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88318690","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}
Globally, millions of waste electrical sockets (WES) are generated annually. This category of waste material is difficult to recycle because they are thermosetting polymers which cannot be remoulded after setting. In this work, the reduction of medium grade Agbaja iron ore from Nigeria, by carbonaceous materials generated from WES was investigated through experiments conducted in a domestic microwave oven. Composite pellets of medium grade Agbaja iron ore (assaying ~74 % Fe 2 O 3 ) with WES were irradiated in a domestic microwave oven (Pioneer, Model PM-25 L, 2450 MHz and 1000 W). The reduced mass was characterised by XRD and SEM/EDS analyses and the extent of reduction after 40 min was determined. SEM/EDS analysis revealed a highly reduced mass with distinct peaks of elemental iron and this was corroborated by XRD analyses that confirmed the formation of metallic iron. The extent of reduction obtained after using WES as reductant was over 80%. Accordingly, carbonaceous materials generated from waste electrical sockets are effective reductants for producing metallic iron from the Agbaja iron ore. Keywords : Waste Electrical Sockets, Thermosetting Polymer, Agbaja Iron Ore; Municipal Solid Waste
{"title":"Recycling Waste Electrical Socket as a Carbon Resource in Ironmaking","authors":"J. R. Dankwah, J. Gordon, P. Koshy","doi":"10.4314/GM.V16I1.9","DOIUrl":"https://doi.org/10.4314/GM.V16I1.9","url":null,"abstract":"Globally, millions of waste electrical sockets (WES) are generated annually. This category of waste material is difficult to recycle because they are thermosetting polymers which cannot be remoulded after setting. In this work, the reduction of medium grade Agbaja iron ore from Nigeria, by carbonaceous materials generated from WES was investigated through experiments conducted in a domestic microwave oven. Composite pellets of medium grade Agbaja iron ore (assaying ~74 % Fe 2 O 3 ) with WES were irradiated in a domestic microwave oven (Pioneer, Model PM-25 L, 2450 MHz and 1000 W). The reduced mass was characterised by XRD and SEM/EDS analyses and the extent of reduction after 40 min was determined. SEM/EDS analysis revealed a highly reduced mass with distinct peaks of elemental iron and this was corroborated by XRD analyses that confirmed the formation of metallic iron. The extent of reduction obtained after using WES as reductant was over 80%. Accordingly, carbonaceous materials generated from waste electrical sockets are effective reductants for producing metallic iron from the Agbaja iron ore. Keywords : Waste Electrical Sockets, Thermosetting Polymer, Agbaja Iron Ore; Municipal Solid Waste","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-12-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85002872","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}
Adansi Gold Company Limited identified an economically viable gold deposit at Nkran in the Amansie West District of Ghana. Mining of this deposit requires the disposal of waste rock materials at a proposed waste rock dump near Nkran and Koninase communities. Since particulates and noise emissions from the operational activities at the dump are inevitable, it becomes necessary to conduct particulates and noise impact studies. The potential impact of particulates and noise from the proposed Nkran waste rock dump on the Koninase and Nkran communities were studied. Baseline TSP, PM10 and noise data were collected over a period of 14 days at the various monitoring locations in the communities. Since the period was characterised by dry weather conditions, TSP (mainly road-induced) were generally higher than permissible levels. PM10 and noise levels compared well with acceptable limits. Results of air quality modelling suggest that occupiers of building structures at Koninase and Nkran may not be affected by particulate emission from the waste dump. However, sound pressure level modelling indicates that the waste rock dump has a potential to alter background noise levels at Koninase and Nkran. Thus, conducting site-specific induction to raise awareness, use of noise bund or green buffers (vegetation) among other recommended strategies would control ambient noise levels. Keywords : Particulates, Noise, Air Pollution, Mining, Waste dump
{"title":"Particulate Matter and Noise Impact Studies of Waste Rock Dump","authors":"K. J. Bansah","doi":"10.4314/GM.V16I1.7","DOIUrl":"https://doi.org/10.4314/GM.V16I1.7","url":null,"abstract":"Adansi Gold Company Limited identified an economically viable gold deposit at Nkran in the Amansie West District of Ghana. Mining of this deposit requires the disposal of waste rock materials at a proposed waste rock dump near Nkran and Koninase communities. Since particulates and noise emissions from the operational activities at the dump are inevitable, it becomes necessary to conduct particulates and noise impact studies. The potential impact of particulates and noise from the proposed Nkran waste rock dump on the Koninase and Nkran communities were studied. Baseline TSP, PM10 and noise data were collected over a period of 14 days at the various monitoring locations in the communities. Since the period was characterised by dry weather conditions, TSP (mainly road-induced) were generally higher than permissible levels. PM10 and noise levels compared well with acceptable limits. Results of air quality modelling suggest that occupiers of building structures at Koninase and Nkran may not be affected by particulate emission from the waste dump. However, sound pressure level modelling indicates that the waste rock dump has a potential to alter background noise levels at Koninase and Nkran. Thus, conducting site-specific induction to raise awareness, use of noise bund or green buffers (vegetation) among other recommended strategies would control ambient noise levels. Keywords : Particulates, Noise, Air Pollution, Mining, Waste dump","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2016-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75816981","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}
Adansi Gold Ghana Ltd has taken over from the then Resolute Amansie Ltd and has three main historical deposits: Nkran, Adubia, Abore, and a new deposit, Asuadai. The company now wants to evaluate the resources at Asuadai which is about 7.5 km from Nkran deposit where Ordinary Kriging (OK) method had been used for estimation. Results of the estimation showed a consistent underestimation of tonnage and grade. Linear estimation models such as OK often produce good estimates but may encounter problems estimating recoverable reserves in cases where the distribution of samples is highly skewed. Multiple Indicator Kriging (MIK) is one of the popular non-linear methods that can handle skewed distribution such as that for gold grades, and addresses some of the deficiencies of the linear methods. This paper compares the estimation results obtained by using MIK and OK for the Asuadai deposit and establishes that MIK presents a better estimate than the OK, and recommends that MIK be used to estimate the gold resources of the Asuadai deposit and other deposits with similar geological settings. Keywords: Indicator Kriging, Ordinary Kriging, Variography, Gold, Outlier
{"title":"Comparison of Ordinary Kriging and Multiple Indicator Kriging Estimates of Asuadai Deposit at Adansi Gold Ghana Limited","authors":"S. Al-Hassan, E. Boamah","doi":"10.4314/GM.V15I2","DOIUrl":"https://doi.org/10.4314/GM.V15I2","url":null,"abstract":"Adansi Gold Ghana Ltd has taken over from the then Resolute Amansie Ltd and has three main historical deposits: Nkran, Adubia, Abore, and a new deposit, Asuadai. The company now wants to evaluate the resources at Asuadai which is about 7.5 km from Nkran deposit where Ordinary Kriging (OK) method had been used for estimation. Results of the estimation showed a consistent underestimation of tonnage and grade. Linear estimation models such as OK often produce good estimates but may encounter problems estimating recoverable reserves in cases where the distribution of samples is highly skewed. Multiple Indicator Kriging (MIK) is one of the popular non-linear methods that can handle skewed distribution such as that for gold grades, and addresses some of the deficiencies of the linear methods. This paper compares the estimation results obtained by using MIK and OK for the Asuadai deposit and establishes that MIK presents a better estimate than the OK, and recommends that MIK be used to estimate the gold resources of the Asuadai deposit and other deposits with similar geological settings. Keywords: Indicator Kriging, Ordinary Kriging, Variography, Gold, Outlier","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-12-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75441692","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}
Cholera outbreak in some cities and towns in Ghana in early 2011 necessitated a sachet water quality study in Tarkwa to determine their wholesomeness. The study was conducted in four phases in August 2011, December 2011, August 2012 and December, 2013. Most of the physico-chemical parameters analysed were within the recommended WHO limits except for pH, Pb and Ni in the main. About 50% of the samples had their pH below the lower limit of 6.5 and 8% had Pb concentrations above the recommended limit of 0.01 mg/L. Protozoan organisms such as Cyclospora cayetanensis (5%), Cryptosporidium parvum (4%), Ascaris lumbricoides eggs (10%), and Stronglyoides Stercoralis larvae (4%) were identified in some of the water samples. Helminth eggs (6.7%), Protista (13.4%) and 6.7% unidentified insect larvae were also found in the samples. Faecal and total coliforms were found in 40% of the samples analysed. The presence of protozoan organisms and faecal coliforms in some of the sachet water render them unsafe for drinking.
{"title":"Quality of Sachet Water Produced at Tarkwa, Ghana","authors":"S. Ndur, J. Kuma, W. Buah, J. Galley","doi":"10.4314/GM.V15I1","DOIUrl":"https://doi.org/10.4314/GM.V15I1","url":null,"abstract":"Cholera outbreak in some cities and towns in Ghana in early 2011 necessitated a sachet water quality study in Tarkwa to determine their wholesomeness. The study was conducted in four phases in August 2011, December 2011, August 2012 and December, 2013. Most of the physico-chemical parameters analysed were within the recommended WHO limits except for pH, Pb and Ni in the main. About 50% of the samples had their pH below the lower limit of 6.5 and 8% had Pb concentrations above the recommended limit of 0.01 mg/L. Protozoan organisms such as Cyclospora cayetanensis (5%), Cryptosporidium parvum (4%), Ascaris lumbricoides eggs (10%), and Stronglyoides Stercoralis larvae (4%) were identified in some of the water samples. Helminth eggs (6.7%), Protista (13.4%) and 6.7% unidentified insect larvae were also found in the samples. Faecal and total coliforms were found in 40% of the samples analysed. The presence of protozoan organisms and faecal coliforms in some of the sachet water render them unsafe for drinking.","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2015-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72745149","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}
J. Addai-Mensah, I. Quaicoe, A. Nosrati, D. Robinson
Although nickel (Ni) laterite ores constitute the majority of Ni mineralization resource world-wide, in contrast to Ni sulphides, their processing via conventional beneficiation (e.g. multi-gravity and flotation) and hydrometallurgical routes is intractable as they are predominantly low grade and complex, both mineralogically and chemically. Due to their physico-chemical character-istics, low grade lateritic ores require more aggressive but costly chemical and hydrometallurgical techniques (e.g., leaching in high pressurized tanks) for value metal (Ni and Co) extraction. Processing such ores through cost-competitive heap (4-10 m high) leaching as an alternative, requires successful agglomeration of the feed into robust and porous granules. To date, produc-ing of granules with desirable attributes poses a major geotechnical challenge to industry. In the present work, we investigate agglomeration behaviour of siliceous goethite Ni laterite ore and selected oxides and clay minerals (hematite, quartz and kao-linite) which constitute the predominant host gangue phases of typical low grade Ni laterite ores. Fundamental knowledge and understanding of the agglomeration mechanisms and kinetics which are essential for producing robust real ore granules, and pivotal to the subsequent heap leaching process, are gleaned. Isothermal, batch agglomeration tests involving 30 and 44 % w/w sulphuric acid solution as a binder indicated that 5 – 40 mm granules of differing roughness and morphologies were produced in 8-14 min. The results showed feed characteristics (e.g., mineralogy and particle size distribution) and binder content (15-25 wt.%) dependent agglomeration behaviour. Slow agglomerate nucleation and growth were displayed by the kaolinite clay min-eral whilst the oxides exhibited faster agglomeration kinetics. Siliceous goethite feed ore fine/coarse ratio, H 2 SO 4 binder dosage and acid content, product drying temperature and aging conditions, all showed significant impact on agglomeration mecha-nisms (e.g., particle wetting, nucleation and growth processes) and granule attributes (e.g., size and strength). Agglomerates strength increased with increasing fine/coarse particle ratio.
{"title":"Understanding Lateritic Ore Agglomeration Behaviour as a Precursor to Enhanced Heap Leaching","authors":"J. Addai-Mensah, I. Quaicoe, A. Nosrati, D. Robinson","doi":"10.4314/GM.V14I0","DOIUrl":"https://doi.org/10.4314/GM.V14I0","url":null,"abstract":"Although nickel (Ni) laterite ores constitute the majority of Ni mineralization resource world-wide, in contrast to Ni sulphides, their processing via conventional beneficiation (e.g. multi-gravity and flotation) and hydrometallurgical routes is intractable as they are predominantly low grade and complex, both mineralogically and chemically. Due to their physico-chemical character-istics, low grade lateritic ores require more aggressive but costly chemical and hydrometallurgical techniques (e.g., leaching in high pressurized tanks) for value metal (Ni and Co) extraction. Processing such ores through cost-competitive heap (4-10 m high) leaching as an alternative, requires successful agglomeration of the feed into robust and porous granules. To date, produc-ing of granules with desirable attributes poses a major geotechnical challenge to industry. In the present work, we investigate agglomeration behaviour of siliceous goethite Ni laterite ore and selected oxides and clay minerals (hematite, quartz and kao-linite) which constitute the predominant host gangue phases of typical low grade Ni laterite ores. Fundamental knowledge and understanding of the agglomeration mechanisms and kinetics which are essential for producing robust real ore granules, and pivotal to the subsequent heap leaching process, are gleaned. Isothermal, batch agglomeration tests involving 30 and 44 % w/w sulphuric acid solution as a binder indicated that 5 – 40 mm granules of differing roughness and morphologies were produced in 8-14 min. The results showed feed characteristics (e.g., mineralogy and particle size distribution) and binder content (15-25 wt.%) dependent agglomeration behaviour. Slow agglomerate nucleation and growth were displayed by the kaolinite clay min-eral whilst the oxides exhibited faster agglomeration kinetics. Siliceous goethite feed ore fine/coarse ratio, H 2 SO 4 binder dosage and acid content, product drying temperature and aging conditions, all showed significant impact on agglomeration mecha-nisms (e.g., particle wetting, nucleation and growth processes) and granule attributes (e.g., size and strength). Agglomerates strength increased with increasing fine/coarse particle ratio.","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2013-07-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73171817","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}
Estimation of gold resources from exploration drilling has passed through various phases and methods at the AngloGold Ashanti, Iduapriem Mine Limited, Tarkwa in Ghana. From the use of Inverse Distance Weighting (IDW) to the use of Ordinary Kriging (OK) and currently the use of Uniform Conditioning (UC). This is all with a view of improving the estimations before the grade control drilling is undertaken for mine planning and subsequent mining. This paper compares the estimates obtained from exploration drilling using conditional simulation with the results from ordinary kriging and actual production figures on a block by block basis for areas that have already been mined in the deposit. The results show that estimates using conditional simulation and ordinary kriging are similar; and, both appear to underestimate the resources.
{"title":"Estimation of Gold Resources from Exploration Drilling using Conditional Simulation - A Case Study","authors":"S. Al-Hassan, J. Kwaha","doi":"10.4314/GM.V13I1","DOIUrl":"https://doi.org/10.4314/GM.V13I1","url":null,"abstract":"Estimation of gold resources from exploration drilling has passed through various phases and methods at the AngloGold Ashanti, Iduapriem Mine Limited, Tarkwa in Ghana. From the use of Inverse Distance Weighting (IDW) to the use of Ordinary Kriging (OK) and currently the use of Uniform Conditioning (UC). This is all with a view of improving the estimations before the grade control drilling is undertaken for mine planning and subsequent mining. This paper compares the estimates obtained from exploration drilling using conditional simulation with the results from ordinary kriging and actual production figures on a block by block basis for areas that have already been mined in the deposit. The results show that estimates using conditional simulation and ordinary kriging are similar; and, both appear to underestimate the resources.","PeriodicalId":12530,"journal":{"name":"Ghana Mining Journal","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2012-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77829270","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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