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© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Nayak, A. R., Jiang, H., Byron, M. L., Sullivan, J. M., McFarland, M. N., & Murphy, D. W. Editorial: small scale spatial and temporal patterns in particles, plankton, and other organisms. Frontiers in Marine Science, 8, (2021): 669530, https://doi.org/10.3389./fmars.2021.669530, Scientists have long known that small-scale interactions of aquatic particles, plankton, and other organisms with their immediate environment play an important role in diverse research areas, including marine ecology, ocean optics, and climate change (Guasto et al., 2012; Prairie et al., 2012). Typically, the distribution of particles and other organisms in the water column tends to be quite “patchy,” i.e., non-homogeneous, both spatially and temporally (Durham and Stocker, 2012). Patchiness can manifest itself through well-known phenomena such as harmful algal blooms (HABs), phytoplankton and zooplankton “thin layers,” deep scattering layers, and schooling of marine organisms such as krill and fish. This non-homogeneous distribution can significantly influence predator-prey encounters and outcomes, export fluxes, marine ecosystem health, and biological productivity (Sullivan et al., 2010; Durham et al., 2013). Thus, there is a continuing need to study and characterize the small-scale biological-physical interactions between particles/organisms and their local environment, as well as the scaled-up effects of these small-scale interactions on larger-scale dynamics. These studies are also directly linked to broader research topics listed as part of the future “grand challenges” in marine ecosystem ecology, as outlined in Borja et al. (2020)., AN was supported through a National Academy of Sciences, Engineering, and Medicine (NASEM) Gulf Research Program (GRP) Early Career Research Fellowship and a faculty start-up grant at Florida Atlantic University. HJ was supported by US National Science Foundation awards (OCE-1559062 and IOS-1353937). MB was supported by a faculty start-up grant at Penn State University. AN, JS, and MM were supported by US National Science Foundation awards (OCE-1634053 and OCE-1657332). DM was supported by the US National Science Foundation (CBET-1846925).

Central to the transformative and developmental power of natural resource extraction is an effective regulatory framework that guides the promotion of investments in the sector and the establishment of effective procedures responsible for the extraction and management of the utilisation of resources. Ghana is currently a lower-middle-income economy with per capita income of about US $ 1 100 and a population of 24 000 000. The country is endowed with signifcant amounts of ferrous and non-ferrous minerals including, gold, bauxite, manganese, diamonds, and iron ore as well as hydrocarbons. It has been mining gold for over a century and currently ranks second only to South Africa in gold production in Africa. Drawing largely on the case of Ghana, this chapter seeks to share the experience of regulation in the extractives sector and offers some perspectives on the purposes, content, and challenges of the practical regulation of an extractives sector in a resource-endowed lower-middle-income economy. The chapter looks at both the design and content of a regulatory system in the mining sector of Ghana and throws light on the practical challenges (technical and political) of implementation. In the light of the increasing allure of resource nationalism the chapter also takes a brief navigation into the manner in which relationships are established and maintained by the regulatory bodies with both large multinational companies and artisanal and smallscale mining operations. Conclusions are drawn to underscore the importance of effective and collaborative regulations in maximising the transformative potential of resource extractions in less developed resource-endowed countries., Central to the transformative and developmental power of natural resource extraction is an effective regulatory framework that guides the promotion of investments in the sector and the establishment of effective procedures responsible for the extraction and management of the utilisation of resources. Ghana is currently a lower-middle-income economy with per capita income of about US $ 1 100 and a population of 24 000 000. The country is endowed with signifcant amounts of ferrous and non-ferrous minerals including, gold, bauxite, manganese, diamonds, and iron ore as well as hydrocarbons. It has been mining gold for over a century and currently ranks second only to South Africa in gold production in Africa. Drawing largely on the case of Ghana, this chapter seeks to share the experience of regulation in the extractives sector and offers some perspectives on the purposes, content, and challenges of the practical regulation of an extractives sector in a resource-endowed lower-middle-income economy. The chapter looks at both the design and content of a regulatory system in the mining sector of Ghana and throws light on the practical challenges (technical and political) of implementation. In the light of the increasing allure of resource nationalism the chapter also takes a brief navigation into the manner in which relationships are established and maintained by the regulatory bodies with both large multinational companies and artisanal and smallscale mining operations. Conclusions are drawn to underscore the importance of effective and collaborative regulations in maximising the transformative potential of resource extractions in less developed resource-endowed countries.

Bulk samples collected from three artisanal and small-scale mining operations in Rwanda were processed on site, using either artisanal measures or basic mechanical methods, in order to evaluate the efficiency of artisanal processing. The ore properties and the applied processing efficiencies were assessed using mineralogical, granulometric and geochemical analyses. An economic analysis of the three mining operations was performed, based on the generated data, to simulate different mineral-pricing situations. The results indicated that the basic mechanical processing schemes provided increases of up to 20% in recovery over the artisanal processing methods. The artisanal processing schemes had a tendency to recover high-grade particles liberated naturally, while disregarding coarse-grain fractions. A profitability analysis of investments showed that mechanical processing was not always preferred over artisanal methods., Bulk samples collected from three artisanal and small-scale mining operations in Rwanda were processed on site, using either artisanal measures or basic mechanical methods, in order to evaluate the efficiency of artisanal processing. The ore properties and the applied processing efficiencies were assessed using mineralogical, granulometric and geochemical analyses. An economic analysis of the three mining operations was performed, based on the generated data, to simulate different mineral-pricing situations. The results indicated that the basic mechanical processing schemes provided increases of up to 20% in recovery over the artisanal processing methods. The artisanal processing schemes had a tendency to recover high-grade particles liberated naturally, while disregarding coarse-grain fractions. A profitability analysis of investments showed that mechanical processing was not always preferred over artisanal methods.

Conventional leach recovery industry tests are often fully monitored, time-consuming and expensive, and may be limiting in geometallurgical applications where large numbers of samples are required to be processed for characterisation of an ore deposit. For characterisation of Olympic Dam uranium-rich samples, BHP Billiton approached CSIRO researchers to develop an affordable and rapid alternative to these full-scale leach tests that could allow for the ranking of samples in terms of their leachability. Kinetic leach tests on samples of small mass were performed using mild, moderate and aggressive conditions of pH, temperature and oxidation reduction potential. This paper presents results from 44 leach tests on 11 samples with varying uranium mineralogy. The developed small-scale tests correlate well with data from the more costly conventional industry laboratory tests, indicating the possibility of using this alternative test as a geometallurgical leach proxy. Simple regression analysis confirmed the influence of pH, reduction potential and temperature on uranium extraction. Experimental data were fitted to published leach models to predict uranium leach extraction for a range of operating conditions., Conventional leach recovery industry tests are often fully monitored, time-consuming and expensive, and may be limiting in geometallurgical applications where large numbers of samples are required to be processed for characterisation of an ore deposit. For characterisation of Olympic Dam uranium-rich samples, BHP Billiton approached CSIRO researchers to develop an affordable and rapid alternative to these full-scale leach tests that could allow for the ranking of samples in terms of their leachability. Kinetic leach tests on samples of small mass were performed using mild, moderate and aggressive conditions of pH, temperature and oxidation reduction potential. This paper presents results from 44 leach tests on 11 samples with varying uranium mineralogy. The developed small-scale tests correlate well with data from the more costly conventional industry laboratory tests, indicating the possibility of using this alternative test as a geometallurgical leach proxy. Simple regression analysis confirmed the influence of pH, reduction potential and temperature on uranium extraction. Experimental data were fitted to published leach models to predict uranium leach extraction for a range of operating conditions.

A geometallurgical model is currently built in two different ways. The first and most common way relies on geometallurgical testing, where a large number of samples are analysed for metallurgical response using small-scale laboratory tests, such as Davis tube testing. The second, mineralogical approach focuses on collecting mineralogical information across the orebody and basing the metallurgical model on mineralogy. At Lulea University of Technology, Sweden, the latter method has been adopted and taken further in four ongoing PhD studies. The geological model gives modal composition with the help of element-to-mineral conversion and Rietveld X-ray diffraction. Texturally, the orebody is divided into different archetypes, and liberation measurements for each of them are carried out in processing fineness using IncaMineral, a SEM-based technique. The grindability and liberation spectrum of any given geological unit (sample, ore block, domain) are extrapolated from the archetypes. The process model is taken into a liberation level by mass balancing selected metallurgical tests using the particle tracking technique. The approach is general and can be applied to any type of ores. Examples of ongoing studies on iron and massive sulphide ores are given. (Authors.), A geometallurgical model is currently built in two different ways. The first and most common way relies on geometallurgical testing, where a large number of samples are analysed for metallurgical response using small-scale laboratory tests, such as Davis tube testing. The second, mineralogical approach focuses on collecting mineralogical information across the orebody and basing the metallurgical model on mineralogy. At Lulea University of Technology, Sweden, the latter method has been adopted and taken further in four ongoing PhD studies. The geological model gives modal composition with the help of element-to-mineral conversion and Rietveld X-ray diffraction. Texturally, the orebody is divided into different archetypes, and liberation measurements for each of them are carried out in processing fineness using IncaMineral, a SEM-based technique. The grindability and liberation spectrum of any given geological unit (sample, ore block, domain) are extrapolated from the archetypes. The process model is taken into a liberation level by mass balancing selected metallurgical tests using the particle tracking technique. The approach is general and can be applied to any type of ores. Examples of ongoing studies on iron and massive sulphide ores are given. (Authors.)

Although dry coal cleaning processes are not as effective as wet methods, they can be technically and financially viable for tasks such as destoning or deshaling. Dry coal processing technologies work without extensive water circuits, or water handling and cleaning systems, and they can be used in semi-mobile plants installed close to the mining face. XRT-sorting is particularly well suited to processing large volumes of coal with very compact installations. Discussion is presented of dry processing technologies, sensor-based sorting, and x-ray transmission detection and sorting. Extensive pilot test work on destoning has been carried out at the Arnot Power Station in South Africa using four difficult-to-treat bituminous coals. Results led to the design of an optimised XRT Chute sorter which is now in operation at a South African coal mine. This flexible semi-mobile modular destoning plant is treating a size range of -120 mm +30 mm at a throughput of 150 tph. The use of this plant has significantly reduced the ash content, abrasiveness index and sulphur content, and has also reduces royalties, water treatment and transport costs., Although dry coal cleaning processes are not as effective as wet methods, they can be technically and financially viable for tasks such as destoning or deshaling. Dry coal processing technologies work without extensive water circuits, or water handling and cleaning systems, and they can be used in semi-mobile plants installed close to the mining face. XRT-sorting is particularly well suited to processing large volumes of coal with very compact installations. Discussion is presented of dry processing technologies, sensor-based sorting, and x-ray transmission detection and sorting. Extensive pilot test work on destoning has been carried out at the Arnot Power Station in South Africa using four difficult-to-treat bituminous coals. Results led to the design of an optimised XRT Chute sorter which is now in operation at a South African coal mine. This flexible semi-mobile modular destoning plant is treating a size range of -120 mm +30 mm at a throughput of 150 tph. The use of this plant has significantly reduced the ash content, abrasiveness index and sulphur content, and has also reduces royalties, water treatment and transport costs.

In spite of the growing use of other size reduction technologies, such as high-pressure grinding rolls and stirred media mills, ball mills are retaining their importance in the minerals industry as the machines responsible for the greatest capital expenditure and installed power inside most mineral processing plants. Mathematical models and formulae have been important tools to assist the engineer in these tasks, having evolved significantly since the middle of the 20th century. Arguably, one of the variables that has presented the greatest challenge when the performance of full-scale mills is to be predicted from data collected in small-scale laboratory mills is the ball size distribution. This paper demonstrates the use of the mechanistic model of the ball mill, which is based on the discrete element method and the population balance model, to predict breakage rates in mills operating with balls of different size. The limitations of investigating ball size effects in small lab mills are discussed on the basis of simulation results., In spite of the growing use of other size reduction technologies, such as high-pressure grinding rolls and stirred media mills, ball mills are retaining their importance in the minerals industry as the machines responsible for the greatest capital expenditure and installed power inside most mineral processing plants. Mathematical models and formulae have been important tools to assist the engineer in these tasks, having evolved significantly since the middle of the 20th century. Arguably, one of the variables that has presented the greatest challenge when the performance of full-scale mills is to be predicted from data collected in small-scale laboratory mills is the ball size distribution. This paper demonstrates the use of the mechanistic model of the ball mill, which is based on the discrete element method and the population balance model, to predict breakage rates in mills operating with balls of different size. The limitations of investigating ball size effects in small lab mills are discussed on the basis of simulation results.

A critical aspect of geometallurgy is quantifying mineralogical and textural relationships that affect mineral processing, such as liberation and recovery. Research is focused on developing methods that will produce the required mineralogical and textural data rapidly and inexpensively. New methods of characterising liberation potential from image analysis of coarse particulate material and direct small-scale flotation measurement are compared with conventional measurement of liberation at final grind size. The new tests are designed to rank the liberation potential of samples in order to classify an ore deposit into domains of low, medium and high liberation potential. This parameter can then be used to adjust the cutoff used to differentiate ore from waste. Results to date show that all tests provide the same ranking for the samples. The measurement based on coarse particulate material compares favourably with the results of mineral liberation analyses on the same samples. Further work is being carried out to determine which of the tests will be the most effective in terms of time, effort and cost., A critical aspect of geometallurgy is quantifying mineralogical and textural relationships that affect mineral processing, such as liberation and recovery. Research is focused on developing methods that will produce the required mineralogical and textural data rapidly and inexpensively. New methods of characterising liberation potential from image analysis of coarse particulate material and direct small-scale flotation measurement are compared with conventional measurement of liberation at final grind size. The new tests are designed to rank the liberation potential of samples in order to classify an ore deposit into domains of low, medium and high liberation potential. This parameter can then be used to adjust the cutoff used to differentiate ore from waste. Results to date show that all tests provide the same ranking for the samples. The measurement based on coarse particulate material compares favourably with the results of mineral liberation analyses on the same samples. Further work is being carried out to determine which of the tests will be the most effective in terms of time, effort and cost.

The AMIRA International P843A Geometallurgical Mapping and Mine Modelling (GeMIII) project is an interdisciplinary research collaboration between 17 global mineral companies and four research organisations aimed at providing support for the emerging industry trend of geometallurgy. The main aim of the project is to develop predictive geometallurgical indices which can be incorporated into a resource block model to maximise the commercial value of an orebody and to minimise the social and environmental impact of mining operations. Researchers at the Parker Centre/CSIRO have been focusing on the development of predictive hydrometallurgical indices for the GeMIII project via rapid, small-scale, cost-effective tests and protocols for comparative ranking of attributes relevant to leach performance. The focus of the small-scale leach tests has been to determine the leach index (relative indication of leach performance), recovery, impurity deportment, reagent consumption, effect of size/degree of liberation and mineralogy of samples for their relative ranking. Predictive tests for heap leach hydrology (related to agglomerate characteristics) and slurry rheological behaviour are also being developed. (Authors.), The AMIRA International P843A Geometallurgical Mapping and Mine Modelling (GeMIII) project is an interdisciplinary research collaboration between 17 global mineral companies and four research organisations aimed at providing support for the emerging industry trend of geometallurgy. The main aim of the project is to develop predictive geometallurgical indices which can be incorporated into a resource block model to maximise the commercial value of an orebody and to minimise the social and environmental impact of mining operations. Researchers at the Parker Centre/CSIRO have been focusing on the development of predictive hydrometallurgical indices for the GeMIII project via rapid, small-scale, cost-effective tests and protocols for comparative ranking of attributes relevant to leach performance. The focus of the small-scale leach tests has been to determine the leach index (relative indication of leach performance), recovery, impurity deportment, reagent consumption, effect of size/degree of liberation and mineralogy of samples for their relative ranking. Predictive tests for heap leach hydrology (related to agglomerate characteristics) and slurry rheological behaviour are also being developed. (Authors.)

The development is described of laboratory equipment, the Ustanov Sorting Laboratory (USL-10), for the small-scale screening of material with sizes of the order of 10 mm. X-ray spectroscopy is used to assess samples for radiometric separation. The system provides a permanent archive of the results of previous and current research and allows the results of future experiments to be predicted using computer calculations., The development is described of laboratory equipment, the Ustanov Sorting Laboratory (USL-10), for the small-scale screening of material with sizes of the order of 10 mm. X-ray spectroscopy is used to assess samples for radiometric separation. The system provides a permanent archive of the results of previous and current research and allows the results of future experiments to be predicted using computer calculations.

Modifications are recommended for Chinese smelters using old-fashioned blast furnaces, Chinese converters and settlers, with simple but effective slag cleaning and granulation to give a very low Cu slag content. In the short term, their economics and efficiency could be greatly improved and their production doubled if cold doping with Chinese converter slag was replaced by the use of white metal, an intermediate product in the copper converter formed between the slag-blowing and the Cu-blowing stages. In the longer term, concentrate should also be replaced by white metal in the blast furnaces used in the Shenyang process, allowing small Chinese smelters to produce almost four times as much copper as at present., Modifications are recommended for Chinese smelters using old-fashioned blast furnaces, Chinese converters and settlers, with simple but effective slag cleaning and granulation to give a very low Cu slag content. In the short term, their economics and efficiency could be greatly improved and their production doubled if cold doping with Chinese converter slag was replaced by the use of white metal, an intermediate product in the copper converter formed between the slag-blowing and the Cu-blowing stages. In the longer term, concentrate should also be replaced by white metal in the blast furnaces used in the Shenyang process, allowing small Chinese smelters to produce almost four times as much copper as at present.

An investigation is described into the application of electronic detonators to control vibration from blasting. An experiment was designed to examine blast data where the ignition timings of the detonators were set to a number of different timing periods. The accuracy of the electronic initiation system was measured using a high-speed data capture system connected to an accelerometer from which vibration traces were obtained. Analysis of the vibration tracers was used to determine the accuracy. The results showed that the use of electronic detonators was highly successful with very high timing accuracy and that the small-scale test blasts can be scaled up to full quarry production blasts to minimise the vibration generated., An investigation is described into the application of electronic detonators to control vibration from blasting. An experiment was designed to examine blast data where the ignition timings of the detonators were set to a number of different timing periods. The accuracy of the electronic initiation system was measured using a high-speed data capture system connected to an accelerometer from which vibration traces were obtained. Analysis of the vibration tracers was used to determine the accuracy. The results showed that the use of electronic detonators was highly successful with very high timing accuracy and that the small-scale test blasts can be scaled up to full quarry production blasts to minimise the vibration generated.

The artisanal and small-scale mining (ASM) sector in sub-Saharan Africa is a sector usually associated with conflict minerals, fatal diseases, smuggling, criminal activity and civil war. Throughout Africa the ASM sector is unfortunately viewed in a negative and distorted manner with little appreciation and understanding for the realities and hardship of miners, their families and communities. However, the sector is burdened and plagued with issues ranging from child labour, gender inequality, the spread of HIV/AIDS, environmental devastation, poor health and safety, migrant workers, lack of capital and fair markets, and conflict with the private large-scale mining sector. This paper discusses the many overlapping and complex drivers, challenges, constraints and issues that characterise the sector and considers potential solutions through the adoption of appropriate best practice, hopefully leading to sustainable livelihoods in the ASM sector and overall poverty alleviation. The paper also highlights ideas of what individual countries can do to help formalise and provide assistance to this vulnerable sector., The artisanal and small-scale mining (ASM) sector in sub-Saharan Africa is a sector usually associated with conflict minerals, fatal diseases, smuggling, criminal activity and civil war. Throughout Africa the ASM sector is unfortunately viewed in a negative and distorted manner with little appreciation and understanding for the realities and hardship of miners, their families and communities. However, the sector is burdened and plagued with issues ranging from child labour, gender inequality, the spread of HIV/AIDS, environmental devastation, poor health and safety, migrant workers, lack of capital and fair markets, and conflict with the private large-scale mining sector. This paper discusses the many overlapping and complex drivers, challenges, constraints and issues that characterise the sector and considers potential solutions through the adoption of appropriate best practice, hopefully leading to sustainable livelihoods in the ASM sector and overall poverty alleviation. The paper also highlights ideas of what individual countries can do to help formalise and provide assistance to this vulnerable sector.

Solomon Islands has a population of around 400 000 mainly Melanesian people distributed across six moderately sized islands and hundreds of smaller islands. The traditional economy has been based on hunther-gather and small-scale farming activities, with the bulk of the population residing in self-sufficient rainforest and coastal villages. Mining and mineral development is one area of economic activity that holds the promise of generating hard currency quickly to develop the country, but that needs to be achieved in a sustainable manner. Gold Ridge is situated in Central Guadalcanal, some 22 km southeast of the capital Honiara, and hosts around 1 400 000 ounces of epithermal volcanic-hosted gold. Ross Mining NL began the construction of the first gold mine in 1997 and operated highly successfully until 2000, when ethnic tensions unrelated to the mine closed the operations. This paper documents the painstaking negotiations and planning that took place from 1993 and particularly from 1995-1996 which paved the way forward for the development of a gold mine within a fragile tropical rainforest environment among traditional Melanesian people who had little prior knowledge of modern mining activities., Solomon Islands has a population of around 400 000 mainly Melanesian people distributed across six moderately sized islands and hundreds of smaller islands. The traditional economy has been based on hunther-gather and small-scale farming activities, with the bulk of the population residing in self-sufficient rainforest and coastal villages. Mining and mineral development is one area of economic activity that holds the promise of generating hard currency quickly to develop the country, but that needs to be achieved in a sustainable manner. Gold Ridge is situated in Central Guadalcanal, some 22 km southeast of the capital Honiara, and hosts around 1 400 000 ounces of epithermal volcanic-hosted gold. Ross Mining NL began the construction of the first gold mine in 1997 and operated highly successfully until 2000, when ethnic tensions unrelated to the mine closed the operations. This paper documents the painstaking negotiations and planning that took place from 1993 and particularly from 1995-1996 which paved the way forward for the development of a gold mine within a fragile tropical rainforest environment among traditional Melanesian people who had little prior knowledge of modern mining activities.

Small-scale mining of gold is now a legally acceptable and important industry in Ghana. The key challenge is to develop strategies to make small-scale gold mining more sustainable, that is, more efficient, less environmentally damaging, in conjunction with greater social benefits. the positive impacts are that it makes a major contribution to foreign exchange earnings of the country; it provides substantial employment to rural communities; it helps stem rural-urban migration; it has been a precursor to large-scale mining; and it enables the exploitation of what otherwise might be uneconomic resources. The negative impacts are that the industry is associated with land degradation, air and water pollution; and social problems such as sexual promiscuity, drug abuse, high cost of living, truancy of both pupils and teachers, land use conflicts between illegal operators and large-scale mines. Strategies for sustainability will involve delineating mineable land, organising illegal operators under a responsible umbrella, supporting small-scale mining operators with funds, technology and education, providing alternative livelihood programs in mining communities, and adopting a pragmatic synergistic approach by all stakeholders in the search for solutions in achieving sustainable development in the small-scale gold mining sector., Small-scale mining of gold is now a legally acceptable and important industry in Ghana. The key challenge is to develop strategies to make small-scale gold mining more sustainable, that is, more efficient, less environmentally damaging, in conjunction with greater social benefits. the positive impacts are that it makes a major contribution to foreign exchange earnings of the country; it provides substantial employment to rural communities; it helps stem rural-urban migration; it has been a precursor to large-scale mining; and it enables the exploitation of what otherwise might be uneconomic resources. The negative impacts are that the industry is associated with land degradation, air and water pollution; and social problems such as sexual promiscuity, drug abuse, high cost of living, truancy of both pupils and teachers, land use conflicts between illegal operators and large-scale mines. Strategies for sustainability will involve delineating mineable land, organising illegal operators under a responsible umbrella, supporting small-scale mining operators with funds, technology and education, providing alternative livelihood programs in mining communities, and adopting a pragmatic synergistic approach by all stakeholders in the search for solutions in achieving sustainable development in the small-scale gold mining sector.

Timor Leste is the newest and one of the poorer nations in the world. One of its main challenges that could lead to poverty reduction is the reconstruction and maintenance of the infrastructures that were almost completely destroyed after its independence referendum. There is an imperative need for construction raw materials in a country where the extractive industry is scarce and artisanal. Available geological studies deal with the island's geology and tectonic evolution or its oil and gas potentialities. A general study of the country's territory demonstrates that it possesses large resources in clays, limestones, and sand and gravel, which can support small- to large-scale raw material extractive industries. Some selected areas have been the target of more detailed study: Venilale and Aileu, with resources for structural ceramics and whiteware respectively, and Beheda, where a crinoid-rich limestone crops out, with potential use as ornamental stone. These resources are suitable for non-sophisticated small-scale mining operations that should be able to accomplish environmental and social liabilities. No public policy exists for the management of these mineral resources, which is essential for the sustainable development of Timor Leste., Timor Leste is the newest and one of the poorer nations in the world. One of its main challenges that could lead to poverty reduction is the reconstruction and maintenance of the infrastructures that were almost completely destroyed after its independence referendum. There is an imperative need for construction raw materials in a country where the extractive industry is scarce and artisanal. Available geological studies deal with the island's geology and tectonic evolution or its oil and gas potentialities. A general study of the country's territory demonstrates that it possesses large resources in clays, limestones, and sand and gravel, which can support small- to large-scale raw material extractive industries. Some selected areas have been the target of more detailed study: Venilale and Aileu, with resources for structural ceramics and whiteware respectively, and Beheda, where a crinoid-rich limestone crops out, with potential use as ornamental stone. These resources are suitable for non-sophisticated small-scale mining operations that should be able to accomplish environmental and social liabilities. No public policy exists for the management of these mineral resources, which is essential for the sustainable development of Timor Leste.

The minerals industry in Zambia will continue to play a key role in fuelling national economic development for many years to come. Particular emphasis should be placed on supporting, developing and harnessing the small-scale mining of gemstones and other precious and semi-precious minerals. These offer perhaps the greatest potential for advancing both development and poverty alleviation in rural communities. The current intervention measures being focused in this sector are therefore crucial. The large-scale mining sector is also on the upswing due to renewed private participation in both the development of new mines, and in the expansion and rehabilitation of existing operations. If currently favourable metal prices and high demand, coupled with good fiscal policies, persists, then total copper-cobalt production will continue to positively contribute substantially to national foreign exchange earnings and the promotion of downstream industries. Sustainable development of resources requires well-qualified personnel in technical fields with managerial administrative skills to formulate appropriate policy frameworks effectively and to implement and monitor the development process of the minerals industry., The minerals industry in Zambia will continue to play a key role in fuelling national economic development for many years to come. Particular emphasis should be placed on supporting, developing and harnessing the small-scale mining of gemstones and other precious and semi-precious minerals. These offer perhaps the greatest potential for advancing both development and poverty alleviation in rural communities. The current intervention measures being focused in this sector are therefore crucial. The large-scale mining sector is also on the upswing due to renewed private participation in both the development of new mines, and in the expansion and rehabilitation of existing operations. If currently favourable metal prices and high demand, coupled with good fiscal policies, persists, then total copper-cobalt production will continue to positively contribute substantially to national foreign exchange earnings and the promotion of downstream industries. Sustainable development of resources requires well-qualified personnel in technical fields with managerial administrative skills to formulate appropriate policy frameworks effectively and to implement and monitor the development process of the minerals industry.

The last two to three decades have witnessed a rapid growth in the mining industry in Kenya. The suite of minerals include metals such as gold, silver, copper, zinc and titanium, and industrial minerals ranging from talc and gypsum to dolomite and gemstones. Methods of exploitation, processing and beneficiation of these mineral resources can have diverse effects on the country's socio-economic position, its varied ecosystems and general environment. The Mining Act (Cap 306) of 1940, which has been the principal Act for regulating minerals use and mining, lacks clear provisions on environmental management. This paper discusses mining guidelines set forth in a new regulatory framework known as the Environmental Management and Coordination Act of 2000, and evaluates their effectiveness and applicability by examining the proposed titanium mining project in the Kwale district. Through a major mining project, the Environmental Impact Assessment exposed the difficulties often encountered in implementing regulatory controls in all new mining ventures, both large- and small-scale. The challenge of sustainability should be a major concern of the minerals industry to demonstrate not only profitability but also benefits to society and preservation of environmental integrity., The last two to three decades have witnessed a rapid growth in the mining industry in Kenya. The suite of minerals include metals such as gold, silver, copper, zinc and titanium, and industrial minerals ranging from talc and gypsum to dolomite and gemstones. Methods of exploitation, processing and beneficiation of these mineral resources can have diverse effects on the country's socio-economic position, its varied ecosystems and general environment. The Mining Act (Cap 306) of 1940, which has been the principal Act for regulating minerals use and mining, lacks clear provisions on environmental management. This paper discusses mining guidelines set forth in a new regulatory framework known as the Environmental Management and Coordination Act of 2000, and evaluates their effectiveness and applicability by examining the proposed titanium mining project in the Kwale district. Through a major mining project, the Environmental Impact Assessment exposed the difficulties often encountered in implementing regulatory controls in all new mining ventures, both large- and small-scale. The challenge of sustainability should be a major concern of the minerals industry to demonstrate not only profitability but also benefits to society and preservation of environmental integrity.

Proposed new smelters are large, usually with capacity for more than 200 000 tons/year of copper, so as to achieve economies of scale, but in a number of cases a much smaller smelter can be economically viable. The economics of a small smelter are examined in terms of transport costs and treatment and refining charges, including payable metals and penalties. Criteria that can be used to select a process for a small smelter are outlined. A dedicated smelter for a mine is likely to be competitive with tolling through a custom smelter if transport costs and impurity levels are high or the concentrates are difficult to treat in a custom smelter., Proposed new smelters are large, usually with capacity for more than 200 000 tons/year of copper, so as to achieve economies of scale, but in a number of cases a much smaller smelter can be economically viable. The economics of a small smelter are examined in terms of transport costs and treatment and refining charges, including payable metals and penalties. Criteria that can be used to select a process for a small smelter are outlined. A dedicated smelter for a mine is likely to be competitive with tolling through a custom smelter if transport costs and impurity levels are high or the concentrates are difficult to treat in a custom smelter.

Papers are presented on upgrading of non-ferrous metal scrap (particularly aluminium)for recycling purposes, a small-scale recycling process for non-ferrous alloys, colour sorting aluminium alloy scrap for recycling, de-coating of aluminium products and the environment, bath recovery from carbon dust by froth flotation, and improving efficiency and emission reduction by regulating source procedures in the secondary aluminium industry., Papers are presented on upgrading of non-ferrous metal scrap (particularly aluminium)for recycling purposes, a small-scale recycling process for non-ferrous alloys, colour sorting aluminium alloy scrap for recycling, de-coating of aluminium products and the environment, bath recovery from carbon dust by froth flotation, and improving efficiency and emission reduction by regulating source procedures in the secondary aluminium industry.

Discussion is presented of the technical and economic factors affecting the recovery of gold by small-scale miners. Gold recovery methods are reviewed with particular attention paid to gravity techniques. Methods are compared on the basis of parameters including cost, manpower and energy requirements, technical expertise, and size range of gold recovered. The efficiency of many small-scale operations is around 30% but considerable improvements should be possible. Case studies were carried out in Guyana and Zimbabwe to test ideas generated by the desk studies and to collect samples for laboratory study. A cost-benefit model of a typical alluvial mine in Guyana shows that changes could pay for themselves in a few months if production were increased by 20%. The case studies showed that, in general, small-scale gold miners have little knowledge about mineral processing and just copy the practices of others in the area. Better recoveries could be obtained by improving knowledge of the importance of grain size distribution and providing good training., Discussion is presented of the technical and economic factors affecting the recovery of gold by small-scale miners. Gold recovery methods are reviewed with particular attention paid to gravity techniques. Methods are compared on the basis of parameters including cost, manpower and energy requirements, technical expertise, and size range of gold recovered. The efficiency of many small-scale operations is around 30% but considerable improvements should be possible. Case studies were carried out in Guyana and Zimbabwe to test ideas generated by the desk studies and to collect samples for laboratory study. A cost-benefit model of a typical alluvial mine in Guyana shows that changes could pay for themselves in a few months if production were increased by 20%. The case studies showed that, in general, small-scale gold miners have little knowledge about mineral processing and just copy the practices of others in the area. Better recoveries could be obtained by improving knowledge of the importance of grain size distribution and providing good training.

Studies were carried out to assess the suitability of coal gold agglomeration for small-scale mining. Batch tests were performed on a synthetic gold ore containing fine gold powder. The slurry was contacted with a mixture of coal and industrial charcoal, after which both the agglomerates and ore were analysed. Operating parameters studied included the mode of contact between the coal-oil phase and the gold-containing slurry, the contact time of slurry and the coal-oil phase, the type of oil, the means of separating the coal-oil gold agglomerates from the slurry, the coal:ore, coal:oil and water:ore ratios, the effect of collectors on the rate of settling, the effectiveness of separating and the mineralogy of the ore. The process yielded promising results, with almost 40% of gold being recovered with contact times above 50 mins., Studies were carried out to assess the suitability of coal gold agglomeration for small-scale mining. Batch tests were performed on a synthetic gold ore containing fine gold powder. The slurry was contacted with a mixture of coal and industrial charcoal, after which both the agglomerates and ore were analysed. Operating parameters studied included the mode of contact between the coal-oil phase and the gold-containing slurry, the contact time of slurry and the coal-oil phase, the type of oil, the means of separating the coal-oil gold agglomerates from the slurry, the coal:ore, coal:oil and water:ore ratios, the effect of collectors on the rate of settling, the effectiveness of separating and the mineralogy of the ore. The process yielded promising results, with almost 40% of gold being recovered with contact times above 50 mins.

The book covers the various methods of recovering and refining precious metals from both primary sources, such as placers, black sands and hard-rock ores, and secondary sources, such as jewellery, electronic scrap, old films, spent plating and stripping solutions and catalytic converters. The information, which is very basic, is intended for hands-on use. Chapters are included on processing ores, chemistry, testing and identification, secondary recovery, platinum group metals, electrochemistry, electrorefining, collecting and separating agents, hydrometallurgy, cyanidation and other processes, black sands, fire assaying, thin-layer chromatography, dip-stick chemistry, solvent extraction, magnetite conversion or reduction, and melting and smelting devices. There is an appendix on black sand assaying, a glossary and an index., The book covers the various methods of recovering and refining precious metals from both primary sources, such as placers, black sands and hard-rock ores, and secondary sources, such as jewellery, electronic scrap, old films, spent plating and stripping solutions and catalytic converters. The information, which is very basic, is intended for hands-on use. Chapters are included on processing ores, chemistry, testing and identification, secondary recovery, platinum group metals, electrochemistry, electrorefining, collecting and separating agents, hydrometallurgy, cyanidation and other processes, black sands, fire assaying, thin-layer chromatography, dip-stick chemistry, solvent extraction, magnetite conversion or reduction, and melting and smelting devices. There is an appendix on black sand assaying, a glossary and an index.

A rotary dry concentrator that can handle, in continuous operation, alluvial deposits in the same size range as those treated by traditional wet plants has been developed in Australia. Four of these units were mounted on an integrated towable treatment plant which has been in successful commercial operation in northern Queensland for 5 years. Grades of less than 0.2 g Au/loose m3 have been profitably mined at throughputs of 80 m3/h at 85% availability, recovering about 85% of the gold in the -12 mm to +0.07 mm fraction. A second single-unit larger module has been successfully tested in the USA, as a prelude to full scale mining, and is also under consideration ahead of the crushing circuit in some heap leach operations. Major benefits, apart from lower capital and operating costs, are environmental: rehabilitation can be completed almost immediately behind the plant as it advances. The principal disadvantage is moisture which restricts the application of the technique., A rotary dry concentrator that can handle, in continuous operation, alluvial deposits in the same size range as those treated by traditional wet plants has been developed in Australia. Four of these units were mounted on an integrated towable treatment plant which has been in successful commercial operation in northern Queensland for 5 years. Grades of less than 0.2 g Au/loose m3 have been profitably mined at throughputs of 80 m3/h at 85% availability, recovering about 85% of the gold in the -12 mm to +0.07 mm fraction. A second single-unit larger module has been successfully tested in the USA, as a prelude to full scale mining, and is also under consideration ahead of the crushing circuit in some heap leach operations. Major benefits, apart from lower capital and operating costs, are environmental: rehabilitation can be completed almost immediately behind the plant as it advances. The principal disadvantage is moisture which restricts the application of the technique.