The study evaluated the milling kinetics of three copper ores, from a multi-mineralised deposit, ... more The study evaluated the milling kinetics of three copper ores, from a multi-mineralised deposit, which were identified as sulphide 1 (with bornite as a dominant copper mineral), sulphide 2 (mainly composed of chalcopyrite) and oxide (with malachite as a dominant copper mineral) and related the breakage parameters to the mineral composition data. Five mono-size fractions between 1000 µm and 212 µm were dry milled for short grinding times in the laboratory ball mill in order to obtain data for predicting breakage rate parameters. The analytical and mineralogical characterisation of the ores were performed using X-ray fluorescence (XRF) analysis, scanning electron microscopy energy dispersive spectroscopy (SEM-EDS) analysis, optical microscopy analysis and X-ray diffractometer (XRD). The mineralogy data showed that quartz was the abundant gangue mineral (average for each ore was above 60% (w/w)), followed by K-feldspar minerals (orthoclase and microcline) which constituted between 4% (...
Figure 1 depicts the schematic diagram of the overall plant. Feed preparation consists of a pair ... more Figure 1 depicts the schematic diagram of the overall plant. Feed preparation consists of a pair of Niro spray dryers, each rated at 50 tph, and a Kvaerner multi-coil steam dryer, also rated at 50 tph, supplying dried concentrate to the flash smelting furnace charge bin via three 1 000 tonne capacity storage silos. The concentrate analysis is typically 5% nickel, 3% copper, 30% sulphur, 45% iron and 8% silica. A pair of loss-in-weight feeders supply 120 tph of concentrate feed to a single concentrate burner, with flux, secondary fuel in the form of milled coal and recycled boiler dust being added ahead of the single burner via an arrangement of bins, feeders and drag link conveyors. This gives a total charge to the furnace in excess of 180 tph. Process air is enriched to 30–35% oxygen and steam preheated to 260°C and supplies of the order of 60 tph of oxygen to the process. Matte produced from the furnace, at a grade of 30–35% combined metal, is upgraded in one of three 30’x13’ Pier...
Namibia is a water stressed country with a limited amount of fresh water. Therefore, the use of w... more Namibia is a water stressed country with a limited amount of fresh water. Therefore, the use of water is an important topic in the country’s development agenda. Water is a shared and finite resource, with high social, cultural, environmental and economic values. However, freshwater resources are under pressure from ore processing, industrialization, urbanization and the demands of a growing population. In Namibia, ore processing, coupled with the anticipated increase in water demand for human consumption and other uses, has created significant stress on its limited water resources. This is critical in mining industry as water remains typically the prime environmental medium (besides air) that is affected by mining activities. This study sought to investigate the strides made in water management in mining, especially in environmentally sensitive areas in Namibia. Most mining companies operate adjacent to or alongside farms, national parks and fishing areas. The overall objective of t...
The Great Dyke is a mineral rich geological feature in the central part of Zimbabwe which stretch... more The Great Dyke is a mineral rich geological feature in the central part of Zimbabwe which stretches for about 550km in the SSW to NNE direction. It hosts, among other mineral resources, the second largest known resources of Platinum Group Minerals after South Africa and the largest high grade chrome ore resources in the world. These ore resources present Zimbabwe with a competitive advantage and a unique opportunity for developing world class mines and processing facilities which could form the backbone of a vibrant metallurgical and manufacturing industry. Given the growing demand for Platinum as a catalyst in reducing air pollution and in jewellery, increased production of Platinum Group Metals (PGMs), their beneficiation and value addition would provide a springboard for socio-economic development of the country.
The depletion of the ore reserves in the world necessitates the search for secondary sources such... more The depletion of the ore reserves in the world necessitates the search for secondary sources such as waste products (tailings and slag). A smelter in Namibia has historic slag which accumulated over decades of its operating life. Analytical and mineralogical characterization of the slag was performed using the X-ray fluorescence (XRF) analysis, Atomic Absorption Spectrometer (AAS), ICP-OES, scanning electron microscopy energy dispersive spectroscopy (SEM-EDS) analysis, and optical microscopy analysis. The chemical analyses showed that the metal values contained in the slag were mainly copper, lead, and zinc whose average contents were approximately 0.3%Cu, 2.4%Pb and 3.2%Zn. About 10.5%Fe was also contained in the slag. Germanium was detected by scanning electron microscopy, but was however below detection limits of the chemical analysis equipment used. Based on the results, approximate conditions under which the different slag phases were formed were estimated and the recovery rout...
Copper slag is generated when copper and nickel ores are recovered from their parent ores using a... more Copper slag is generated when copper and nickel ores are recovered from their parent ores using a pyrometallurgical process, and these ores usually contain other elements which include iron, cobalt, silica, and alumina. Slag is a major problem in the metallurgical industries as it is dumped into heaps which have accumulated into millions of tons over the years. Moreover, they pose a danger to the environment as they occupy vacant land (space problems). Over the past few years, studies have been conducted to investigate the copper slag-producing outlets to learn their behavior, as well as properties of slag, to have the knowledge of how to better reuse and recycle copper slag. This review article provides the environmental and socioeconomic impacts of slag, as well as a characterization of copper slag, with the aim of reusing and recycling the slag to benefit the environment and economy. Recycling methods are considered an attractive technological pathway for reducing waste and green...
Journal- South African Institute of Mining and Metallurgy
The mining industry worldwide is facing a tremendous shortage of minerals engineers in all fields... more The mining industry worldwide is facing a tremendous shortage of minerals engineers in all fields of specialization. For instance, in Australia the skills shortage in the mining industry has been identified as one of the top risks facing the mining industry. In Namibia most minerals engineers employed are expatriates, with some being Namibians who studied abroad. The minerals engineering programmes at the Polytechnic of Namibia are still in their infancy. These programmes were designed to meet the mining industry skills needs. Being young has its advantages in that lessons can be learnt from older minerals education institutions that went through similar challenges. However, this does not imply just copying and implementing their approaches, since the context differs and, to ensure sustainability of the minerals education programmes, curricula have to be customized to the local context. This paper reviews the interventions made by the Polytechnic of Namibia in order to ensure the su...
Journal- South African Institute of Mining and Metallurgy
The mining industry worldwide is facing a tremendous shortage of minerals engineers in all fields... more The mining industry worldwide is facing a tremendous shortage of minerals engineers in all fields of specialization. For instance, in Australia the skills shortage in the mining industry has been identified as one of the top risks facing the mining industry. In Namibia most minerals engineers employed are expatriates, with some being Namibians who studied abroad. The minerals engineering programmes at the Polytechnic of Namibia are still in their infancy. These programmes were designed to meet the mining industry skills needs. Being young has its advantages in that lessons can be learnt from older minerals education institutions that went through similar challenges. However, this does not imply just copying and implementing their approaches, since the context differs and, to ensure sustainability of the minerals education programmes, curricula have to be customized to the local context. This paper reviews the interventions made by the Polytechnic of Namibia in order to ensure the su...
The study evaluated the milling kinetics of three copper ores, from a multi-mineralised deposit, ... more The study evaluated the milling kinetics of three copper ores, from a multi-mineralised deposit, which were identified as sulphide 1 (with bornite as a dominant copper mineral), sulphide 2 (mainly composed of chalcopyrite) and oxide (with malachite as a dominant copper mineral) and related the breakage parameters to the mineral composition data. Five mono-size fractions between 1000 µm and 212 µm were dry milled for short grinding times in the laboratory ball mill in order to obtain data for predicting breakage rate parameters. The analytical and mineralogical characterisation of the ores were performed using X-ray fluorescence (XRF) analysis, scanning electron microscopy energy dispersive spectroscopy (SEM-EDS) analysis, optical microscopy analysis and X-ray diffractometer (XRD). The mineralogy data showed that quartz was the abundant gangue mineral (average for each ore was above 60% (w/w)), followed by K-feldspar minerals (orthoclase and microcline) which constituted between 4% (...
Figure 1 depicts the schematic diagram of the overall plant. Feed preparation consists of a pair ... more Figure 1 depicts the schematic diagram of the overall plant. Feed preparation consists of a pair of Niro spray dryers, each rated at 50 tph, and a Kvaerner multi-coil steam dryer, also rated at 50 tph, supplying dried concentrate to the flash smelting furnace charge bin via three 1 000 tonne capacity storage silos. The concentrate analysis is typically 5% nickel, 3% copper, 30% sulphur, 45% iron and 8% silica. A pair of loss-in-weight feeders supply 120 tph of concentrate feed to a single concentrate burner, with flux, secondary fuel in the form of milled coal and recycled boiler dust being added ahead of the single burner via an arrangement of bins, feeders and drag link conveyors. This gives a total charge to the furnace in excess of 180 tph. Process air is enriched to 30–35% oxygen and steam preheated to 260°C and supplies of the order of 60 tph of oxygen to the process. Matte produced from the furnace, at a grade of 30–35% combined metal, is upgraded in one of three 30’x13’ Pier...
Namibia is a water stressed country with a limited amount of fresh water. Therefore, the use of w... more Namibia is a water stressed country with a limited amount of fresh water. Therefore, the use of water is an important topic in the country’s development agenda. Water is a shared and finite resource, with high social, cultural, environmental and economic values. However, freshwater resources are under pressure from ore processing, industrialization, urbanization and the demands of a growing population. In Namibia, ore processing, coupled with the anticipated increase in water demand for human consumption and other uses, has created significant stress on its limited water resources. This is critical in mining industry as water remains typically the prime environmental medium (besides air) that is affected by mining activities. This study sought to investigate the strides made in water management in mining, especially in environmentally sensitive areas in Namibia. Most mining companies operate adjacent to or alongside farms, national parks and fishing areas. The overall objective of t...
The Great Dyke is a mineral rich geological feature in the central part of Zimbabwe which stretch... more The Great Dyke is a mineral rich geological feature in the central part of Zimbabwe which stretches for about 550km in the SSW to NNE direction. It hosts, among other mineral resources, the second largest known resources of Platinum Group Minerals after South Africa and the largest high grade chrome ore resources in the world. These ore resources present Zimbabwe with a competitive advantage and a unique opportunity for developing world class mines and processing facilities which could form the backbone of a vibrant metallurgical and manufacturing industry. Given the growing demand for Platinum as a catalyst in reducing air pollution and in jewellery, increased production of Platinum Group Metals (PGMs), their beneficiation and value addition would provide a springboard for socio-economic development of the country.
The depletion of the ore reserves in the world necessitates the search for secondary sources such... more The depletion of the ore reserves in the world necessitates the search for secondary sources such as waste products (tailings and slag). A smelter in Namibia has historic slag which accumulated over decades of its operating life. Analytical and mineralogical characterization of the slag was performed using the X-ray fluorescence (XRF) analysis, Atomic Absorption Spectrometer (AAS), ICP-OES, scanning electron microscopy energy dispersive spectroscopy (SEM-EDS) analysis, and optical microscopy analysis. The chemical analyses showed that the metal values contained in the slag were mainly copper, lead, and zinc whose average contents were approximately 0.3%Cu, 2.4%Pb and 3.2%Zn. About 10.5%Fe was also contained in the slag. Germanium was detected by scanning electron microscopy, but was however below detection limits of the chemical analysis equipment used. Based on the results, approximate conditions under which the different slag phases were formed were estimated and the recovery rout...
Copper slag is generated when copper and nickel ores are recovered from their parent ores using a... more Copper slag is generated when copper and nickel ores are recovered from their parent ores using a pyrometallurgical process, and these ores usually contain other elements which include iron, cobalt, silica, and alumina. Slag is a major problem in the metallurgical industries as it is dumped into heaps which have accumulated into millions of tons over the years. Moreover, they pose a danger to the environment as they occupy vacant land (space problems). Over the past few years, studies have been conducted to investigate the copper slag-producing outlets to learn their behavior, as well as properties of slag, to have the knowledge of how to better reuse and recycle copper slag. This review article provides the environmental and socioeconomic impacts of slag, as well as a characterization of copper slag, with the aim of reusing and recycling the slag to benefit the environment and economy. Recycling methods are considered an attractive technological pathway for reducing waste and green...
Journal- South African Institute of Mining and Metallurgy
The mining industry worldwide is facing a tremendous shortage of minerals engineers in all fields... more The mining industry worldwide is facing a tremendous shortage of minerals engineers in all fields of specialization. For instance, in Australia the skills shortage in the mining industry has been identified as one of the top risks facing the mining industry. In Namibia most minerals engineers employed are expatriates, with some being Namibians who studied abroad. The minerals engineering programmes at the Polytechnic of Namibia are still in their infancy. These programmes were designed to meet the mining industry skills needs. Being young has its advantages in that lessons can be learnt from older minerals education institutions that went through similar challenges. However, this does not imply just copying and implementing their approaches, since the context differs and, to ensure sustainability of the minerals education programmes, curricula have to be customized to the local context. This paper reviews the interventions made by the Polytechnic of Namibia in order to ensure the su...
Journal- South African Institute of Mining and Metallurgy
The mining industry worldwide is facing a tremendous shortage of minerals engineers in all fields... more The mining industry worldwide is facing a tremendous shortage of minerals engineers in all fields of specialization. For instance, in Australia the skills shortage in the mining industry has been identified as one of the top risks facing the mining industry. In Namibia most minerals engineers employed are expatriates, with some being Namibians who studied abroad. The minerals engineering programmes at the Polytechnic of Namibia are still in their infancy. These programmes were designed to meet the mining industry skills needs. Being young has its advantages in that lessons can be learnt from older minerals education institutions that went through similar challenges. However, this does not imply just copying and implementing their approaches, since the context differs and, to ensure sustainability of the minerals education programmes, curricula have to be customized to the local context. This paper reviews the interventions made by the Polytechnic of Namibia in order to ensure the su...
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