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Life-cycle assessments are presented for conversion processes and techniques covering solid, gaseous and fuels such as coal, petroleum coke, oil shale, tar sands, bitumen, natural and synthetic gas, SO2 removal, biodiesel, vegetable oil and petroleum. As well as outlines of schematic life-cycle assessment procedures, diagrams are included of: oil-shale project environmental impacts; mass and energy flows in the Alberta Taciuk processor retort; system boundaries for the desulphurisation process; a full service cycle for total catalyst management; a Grassmann diagram from naphtha to reformate; and system boundaries for electricity generation from black or brown coals. Graphs and bar charts compare life-time greenhouse gas emissions of petroleum-based and coal-based fuels, costs and impacts of different gasification routes, fuel-oil price equivalent versus carbon emissions per km driven, and fossil energy embedded in the productrion of hydro-treated vegetable oil biofuels from rape, palm and jatropha with rapeseed methyl ester as a control. It is concluded that different LCAs can express different impacts, depending on how the different elements of the life-cycle assessment framework have been implemented.An LCA outcome therefore needs to be viewed in terms of its scope definition, how the data was gathered during the inventory analysis and analysed during the impact assessment, and how the overall interpretation was conducted.The framework needs to be further standardised in the area of hydrocarbon fuel conversion and robust databases built that can help reduce sensitivity issues and uncertainties., Life-cycle assessments are presented for conversion processes and techniques covering solid, gaseous and fuels such as coal, petroleum coke, oil shale, tar sands, bitumen, natural and synthetic gas, SO2 removal, biodiesel, vegetable oil and petroleum. As well as outlines of schematic life-cycle assessment procedures, diagrams are included of: oil-shale project environmental impacts; mass and energy flows in the Alberta Taciuk processor retort; system boundaries for the desulphurisation process; a full service cycle for total catalyst management; a Grassmann diagram from naphtha to reformate; and system boundaries for electricity generation from black or brown coals. Graphs and bar charts compare life-time greenhouse gas emissions of petroleum-based and coal-based fuels, costs and impacts of different gasification routes, fuel-oil price equivalent versus carbon emissions per km driven, and fossil energy embedded in the productrion of hydro-treated vegetable oil biofuels from rape, palm and jatropha with rapeseed methyl ester as a control. It is concluded that different LCAs can express different impacts, depending on how the different elements of the life-cycle assessment framework have been implemented.An LCA outcome therefore needs to be viewed in terms of its scope definition, how the data was gathered during the inventory analysis and analysed during the impact assessment, and how the overall interpretation was conducted.The framework needs to be further standardised in the area of hydrocarbon fuel conversion and robust databases built that can help reduce sensitivity issues and uncertainties.

The discovery in 1921 is described of what was claimed to be a very large oil field in the West Somerset shales. Subsequent investigations carried out in June 1924 showed that the quality and quantity of the oil was not as had been indicated. The crude oil was heavy and with a low yield of distillate. It had a high sulphur content and the volume obtained per ton of shale was considerably less than claimed. The refining retort at Kilve was finally closed in August 1924, ending the oil field's operations., The discovery in 1921 is described of what was claimed to be a very large oil field in the West Somerset shales. Subsequent investigations carried out in June 1924 showed that the quality and quantity of the oil was not as had been indicated. The crude oil was heavy and with a low yield of distillate. It had a high sulphur content and the volume obtained per ton of shale was considerably less than claimed. The refining retort at Kilve was finally closed in August 1924, ending the oil field's operations.

The vapourisation characteristics of different Hg compounds that might be present in acid-plant blow-down sludge were investigated and the minimum temperature to obtain 100% vapourisation in 60 min was determined for each. For a reactor pressure of 50 Torr, the required temperatures in degrees C were 634 for Hg2SO4, 622 for HgSO4, 603 for HgSO4.2HgO, 557 for HgO, 451 for HgSe and 382 for HgS. Mercury vapour back-reacted with other gas species to a significant extent: virtually no metallic Hg was collected from HgS and HgSe, around 10% from Hg2SO4 and HgSO4 and 50% from HgSO4.2HgO; only from HgO was the recovered Hg primarily in elemental form. The application of the results to operation of a vacuum retort and condenser system is discussed., The vapourisation characteristics of different Hg compounds that might be present in acid-plant blow-down sludge were investigated and the minimum temperature to obtain 100% vapourisation in 60 min was determined for each. For a reactor pressure of 50 Torr, the required temperatures in degrees C were 634 for Hg2SO4, 622 for HgSO4, 603 for HgSO4.2HgO, 557 for HgO, 451 for HgSe and 382 for HgS. Mercury vapour back-reacted with other gas species to a significant extent: virtually no metallic Hg was collected from HgS and HgSe, around 10% from Hg2SO4 and HgSO4 and 50% from HgSO4.2HgO; only from HgO was the recovered Hg primarily in elemental form. The application of the results to operation of a vacuum retort and condenser system is discussed.

Artisanal mining provides employment for nearly 500 000 people and earns foreign currency in Tanzania. The lack of mining knowledge, appropriate equipment and infrastructure has resulted in dangerous mining practices. A government programme aimed at promoting safe and sustainable mining practices in the gold mining areas of Lake Victoria is discussed., Artisanal mining provides employment for nearly 500 000 people and earns foreign currency in Tanzania. The lack of mining knowledge, appropriate equipment and infrastructure has resulted in dangerous mining practices. A government programme aimed at promoting safe and sustainable mining practices in the gold mining areas of Lake Victoria is discussed.

Projekt-Consult GmbH is working with GATE (German Appropriate Technology Exchange) within GTZ (German Agency for Technical Cooperation) on a project called Tools for Mining. The aim of the project is to propose technical solutions to small-scale mining problems in developing countries. A manual has been produced comprising 125 different techniques and machines. Datasheets for each technique include technical and economic data, hints on local manufacture, photographs and drawings. Care has been taken to ensure the use of environmentally sound technology. The handbook also includes lists of manufacturers and literature references. A five month pilot study examined the use of the handbook in practical projects with CORPONARINO, a Colombian regional development organisation. Improvements were made in the gold processing systems which improved recovery and prevented the release of mercury., Projekt-Consult GmbH is working with GATE (German Appropriate Technology Exchange) within GTZ (German Agency for Technical Cooperation) on a project called Tools for Mining. The aim of the project is to propose technical solutions to small-scale mining problems in developing countries. A manual has been produced comprising 125 different techniques and machines. Datasheets for each technique include technical and economic data, hints on local manufacture, photographs and drawings. Care has been taken to ensure the use of environmentally sound technology. The handbook also includes lists of manufacturers and literature references. A five month pilot study examined the use of the handbook in practical projects with CORPONARINO, a Colombian regional development organisation. Improvements were made in the gold processing systems which improved recovery and prevented the release of mercury.

Mercury discharge from informal gold mining activities in the Amazon region derives from a lack of concern on the part of the miners and poor knowledge of efficient extraction methods. High Hg blood levels have been found in fish eating people and high levels in urine in workers burning amalgam daily. The educational measures being implemented by some Brazilian institutions to minimise mercury emissions include: visual publications (brochures, videos); meetings; promoting simple home made retorts; and computer systems. HgEX is an expert system developed in simple language, by the university of British Columbia, to provide a diagnosis of the extent of mercury pollution in a region or at a single mining site. It is designed for use by either highly skilled professionals or uneducated mining personnel., Mercury discharge from informal gold mining activities in the Amazon region derives from a lack of concern on the part of the miners and poor knowledge of efficient extraction methods. High Hg blood levels have been found in fish eating people and high levels in urine in workers burning amalgam daily. The educational measures being implemented by some Brazilian institutions to minimise mercury emissions include: visual publications (brochures, videos); meetings; promoting simple home made retorts; and computer systems. HgEX is an expert system developed in simple language, by the university of British Columbia, to provide a diagnosis of the extent of mercury pollution in a region or at a single mining site. It is designed for use by either highly skilled professionals or uneducated mining personnel.

The purpose of this project is to determine the feasibility of using institutional-size pouches to package and process shelf stable particulate food products. Food Innovisions, Inc. packaged and processed two particulate type products, Chicken a la King and Beef Stew, in institutional-size retort pouches for shipment to U.S. Army Natick Research, Development and Engineering Center. At the conclusion of this segment of the project, evaluation of this packaging system will be performed at the Natick RD&E Center., Prepared in cooperation with Food Innovisions, Inc., New Orleans, LA, and Exxon Chemical Co., Houston, TX.

The publication consists of four parts. Part A: general context has 3 chapters covering zinc industry perspective and introduction, historical background and raw materials. Part B: the electrolytic process contains 7 chapters on roasting, leaching and solution preparation, solution purification, electrolysis, melting and casting, material balance control and effluent treatment, and other electrolytic processes. Part C: carbothermic reduction processes includes 8 chapters on carbothermic reduction, sintering, retorting processes, blast furnace production of zinc, thermal refining of zinc, zinc fuming processes, electric furnace reduction processes and other pyrometallurgical reduction processes. Part D: general and comparative aspects of major zinc production processes has four chapters covering treatment of oxide and secondary materials, energy consumption, costs and economics of the electrolytic zinc process, and costs and economics of the ISF (Imperial smelting furnace) process. An appendix covers the properties of zinc and related compounds., The publication consists of four parts. Part A: general context has 3 chapters covering zinc industry perspective and introduction, historical background and raw materials. Part B: the electrolytic process contains 7 chapters on roasting, leaching and solution preparation, solution purification, electrolysis, melting and casting, material balance control and effluent treatment, and other electrolytic processes. Part C: carbothermic reduction processes includes 8 chapters on carbothermic reduction, sintering, retorting processes, blast furnace production of zinc, thermal refining of zinc, zinc fuming processes, electric furnace reduction processes and other pyrometallurgical reduction processes. Part D: general and comparative aspects of major zinc production processes has four chapters covering treatment of oxide and secondary materials, energy consumption, costs and economics of the electrolytic zinc process, and costs and economics of the ISF (Imperial smelting furnace) process. An appendix covers the properties of zinc and related compounds.

A laboratory study of the separation and recycling of spent carbon cathode blocks from a failure pot of Fushun aluminium smelter (pot life 6 y) in China is presented. The vacuum-distillation process consists of distillation of the electrolyte and sodium from the spent carbon cathode block at 1 100-1 200 degrees C under a vacuum of less than 10 Pa in a horizontal thermal-reduction retort, leaving a non-distillable residue containing mostly carbon. The results show that, using a distillation temperature of 1 200 degrees C, a distillation time of 90 min and a vacuum of under 10 Pa, Na3AlF6 (ca 54%) and NaF (ca 46%) (from the electrolyte) and sodium metal are vacuum distilled from the spent carbon cathode block, the distillation ratio exceeds 80% and the carbon content of the distillation residue is 91.20% with impurities of CaF2 (ca 4%), Al2O3 (2-3%), Fe2O3, SiO2 and other oxides (1-2%) and sodium (below 0.2%)., A laboratory study of the separation and recycling of spent carbon cathode blocks from a failure pot of Fushun aluminium smelter (pot life 6 y) in China is presented. The vacuum-distillation process consists of distillation of the electrolyte and sodium from the spent carbon cathode block at 1 100-1 200 degrees C under a vacuum of less than 10 Pa in a horizontal thermal-reduction retort, leaving a non-distillable residue containing mostly carbon. The results show that, using a distillation temperature of 1 200 degrees C, a distillation time of 90 min and a vacuum of under 10 Pa, Na3AlF6 (ca 54%) and NaF (ca 46%) (from the electrolyte) and sodium metal are vacuum distilled from the spent carbon cathode block, the distillation ratio exceeds 80% and the carbon content of the distillation residue is 91.20% with impurities of CaF2 (ca 4%), Al2O3 (2-3%), Fe2O3, SiO2 and other oxides (1-2%) and sodium (below 0.2%).

China is the world’s largest Pb and Zn producer and consumer, accounting for almost fifty percent of the global totals. Lead smelting processes include the oxygen bottom blowing process, the Kivcet flash smelting process, oxygen-enriched air top blowing processes such as the ISA and Ausmelt processes, and the double side-blowing smelting process based on the use of a Vanyukov furnace. Plants based on the QSL and Kaldo direct smelting processes have both been closed, with the latter subsequently modified to an oxygen bottom blowing smelter. Details are given of the SKS oxygen bottom blowing technology which was developed in China and includes an oxidation-blast furnace reduction process and an oxidation-liquid Pb slag reduction process using bottom blowing/side blowing. The process is environmentally friendly, can be used for sulphide and oxide ores of various grades, provides high recoveries, has low production costs and exhibits simple and flexible operation. Secondary lead smelting technologies include reverberatory furnaces, blast furnaces, rotary furnaces for Pb paste desulphurisation and the side-submerged combustion smelting process which has been developed in China for liquid high-Pb slag reduction. Pyrometallurgical processes for Zn production include the vertical retort process, the ISP blast furnace process for Zn-Pb sulphide concentrate and electric furnace smelting. Zn hydrometallurgical processes are also reviewed, including fluidised roasting of Zn concentrate, two-stage leaching and leaching residue volatilisation in a kiln, the hot acid leaching-jarosite process, hot acid leaching-goethite process, direct leaching process for sulphide concentrate and the oxide direct leaching/solvent extraction process. Leach residue treatments include the fuming furnace process, the top blowing furnace process, the rotary kiln process and the oxygen-enriched side blowing submerged combustion process., China is the world’s largest Pb and Zn producer and consumer, accounting for almost fifty percent of the global totals. Lead smelting processes include the oxygen bottom blowing process, the Kivcet flash smelting process, oxygen-enriched air top blowing processes such as the ISA and Ausmelt processes, and the double side-blowing smelting process based on the use of a Vanyukov furnace. Plants based on the QSL and Kaldo direct smelting processes have both been closed, with the latter subsequently modified to an oxygen bottom blowing smelter. Details are given of the SKS oxygen bottom blowing technology which was developed in China and includes an oxidation-blast furnace reduction process and an oxidation-liquid Pb slag reduction process using bottom blowing/side blowing. The process is environmentally friendly, can be used for sulphide and oxide ores of various grades, provides high recoveries, has low production costs and exhibits simple and flexible operation. Secondary lead smelting technologies include reverberatory furnaces, blast furnaces, rotary furnaces for Pb paste desulphurisation and the side-submerged combustion smelting process which has been developed in China for liquid high-Pb slag reduction. Pyrometallurgical processes for Zn production include the vertical retort process, the ISP blast furnace process for Zn-Pb sulphide concentrate and electric furnace smelting. Zn hydrometallurgical processes are also reviewed, including fluidised roasting of Zn concentrate, two-stage leaching and leaching residue volatilisation in a kiln, the hot acid leaching-jarosite process, hot acid leaching-goethite process, direct leaching process for sulphide concentrate and the oxide direct leaching/solvent extraction process. Leach residue treatments include the fuming furnace process, the top blowing furnace process, the rotary kiln process and the oxygen-enriched side blowing submerged combustion process.

The downward spiral of titanium in the USA: has it reached the bottom? Expansion for the future at IMI Titanium; Titanium granules from Deeside; Cabot's new multi-purpose mill; MB conference - Titanium and the Superalloys., The downward spiral of titanium in the USA: has it reached the bottom? Expansion for the future at IMI Titanium; Titanium granules from Deeside; Cabot's new multi-purpose mill; MB conference - Titanium and the Superalloys.

Several potential hazards were encountered in the company's in situ oil shale retorting project at its Tract C-a lease in the Piceance Creek Basin of northwestern Colorado. This was the first project with shafts rather than adits for access to the mining operation. Methane and hydrogen sulphide, in association with ground water was found. In order to burn the underground retorts it was necessary to provide for potential leakage for retort gases and to obtain a modification to the MSHA standard which forbids fires underground. An extensive underground air monitoring programme was included in the ventilation system., Several potential hazards were encountered in the company's in situ oil shale retorting project at its Tract C-a lease in the Piceance Creek Basin of northwestern Colorado. This was the first project with shafts rather than adits for access to the mining operation. Methane and hydrogen sulphide, in association with ground water was found. In order to burn the underground retorts it was necessary to provide for potential leakage for retort gases and to obtain a modification to the MSHA standard which forbids fires underground. An extensive underground air monitoring programme was included in the ventilation system.

Directly Reduced Iron (DRI) is produced in four different reactors: shaft (moving bed), rotary kiln, fluidised bed, and retort (fixed bed). Annual worldwide production capacity approaches 33 million tonnes. Detailed assessments have been made of the uses of DRI, especially as a substitute for scrap in electric furnace steel making., Directly Reduced Iron (DRI) is produced in four different reactors: shaft (moving bed), rotary kiln, fluidised bed, and retort (fixed bed). Annual worldwide production capacity approaches 33 million tonnes. Detailed assessments have been made of the uses of DRI, especially as a substitute for scrap in electric furnace steel making.

The future of zinc smelting processes largely depends on the cost of the energy required to run them. The pyrometallurgical process, including the vertical retort process, has more energy saving potential than the electrolytic process. The vertical retort process also has the capacity to treat some complex and recycled zinc materials more efficiently than hydrometallurgical processes. It is also possible to recover valuable impurities economically by suitable treatment of the zinc-cadmium alloy, blister lead and hard zinc produced as intermediates in the vertical retort process., The future of zinc smelting processes largely depends on the cost of the energy required to run them. The pyrometallurgical process, including the vertical retort process, has more energy saving potential than the electrolytic process. The vertical retort process also has the capacity to treat some complex and recycled zinc materials more efficiently than hydrometallurgical processes. It is also possible to recover valuable impurities economically by suitable treatment of the zinc-cadmium alloy, blister lead and hard zinc produced as intermediates in the vertical retort process.

In April 2000 a UNIDO study was carried out in Dumasi, a village near the Bogoso mine where 20-25% of the adults are involved in local artisanal gold production, to determine the environmental impacts of mercury prior to the introduction of retorts. A sampling programme was intended to identify mercury transfers to rivers, soil systems and groundwater. Results showed no evidence of groundwater contamination but sediments were significantly contaminated and most fish fillets had Hg contents exceeding the US Food and Drug Agency action level, making them unfit for human consumption. Hg losses occurred mainly during amalgamation and had resulted in widespread pollution of soils and sediments throughout the village. The introduction of transparent retorts and ongoing environmental training have only partially addressed the problem., In April 2000 a UNIDO study was carried out in Dumasi, a village near the Bogoso mine where 20-25% of the adults are involved in local artisanal gold production, to determine the environmental impacts of mercury prior to the introduction of retorts. A sampling programme was intended to identify mercury transfers to rivers, soil systems and groundwater. Results showed no evidence of groundwater contamination but sediments were significantly contaminated and most fish fillets had Hg contents exceeding the US Food and Drug Agency action level, making them unfit for human consumption. Hg losses occurred mainly during amalgamation and had resulted in widespread pollution of soils and sediments throughout the village. The introduction of transparent retorts and ongoing environmental training have only partially addressed the problem.

Electrometallurgy is currently dominated by the production of aluminium, the electrorefining of copper and the electrowinning of zinc. It has also been successful in the electrowinning of copper from solutions obtained by leaching-solvent extraction. Discussion is presented of hydro- versus pyrometallurgy, including: the retort process, roasting-leaching-electrowinning and the pressure leaching process for zinc; the thermal and aqueous oxidation processes for gold; horizontal and vertical furnaces, smelting and future technologies for copper; and anodic dissolution, the INCO process and hydrometallurgy of nickel. With the increased tendency towards pressure leaching to replace smelting there will be a corresponding increase in electrowinning operations, and improvement of the present technology is necessary., Electrometallurgy is currently dominated by the production of aluminium, the electrorefining of copper and the electrowinning of zinc. It has also been successful in the electrowinning of copper from solutions obtained by leaching-solvent extraction. Discussion is presented of hydro- versus pyrometallurgy, including: the retort process, roasting-leaching-electrowinning and the pressure leaching process for zinc; the thermal and aqueous oxidation processes for gold; horizontal and vertical furnaces, smelting and future technologies for copper; and anodic dissolution, the INCO process and hydrometallurgy of nickel. With the increased tendency towards pressure leaching to replace smelting there will be a corresponding increase in electrowinning operations, and improvement of the present technology is necessary.

Processes that take advantage of Mg's low boiling temperature are the Pidgeon process, Bolzano process and Magnetherm process, in all of which the product of reduction with ferrosilicon and bauxite is Mg vapour which can be condensed. Contaminated Mg scrap can be fed to the winning process with liquid slag or processed in distillation units like vertical Pidgeon retorts and vacuum induction furnaces. Drawbacks are the slow reaction rates, which are much lower than those expected from molecular distillation, the batch-wise processing and the unequal conditions in different countries for establishing and running a plant. Nevertheless, it is concluded that a distillation plant with a vacuum induction furnace processing post-consumer scrap could operate economically in western Europe., Processes that take advantage of Mg's low boiling temperature are the Pidgeon process, Bolzano process and Magnetherm process, in all of which the product of reduction with ferrosilicon and bauxite is Mg vapour which can be condensed. Contaminated Mg scrap can be fed to the winning process with liquid slag or processed in distillation units like vertical Pidgeon retorts and vacuum induction furnaces. Drawbacks are the slow reaction rates, which are much lower than those expected from molecular distillation, the batch-wise processing and the unequal conditions in different countries for establishing and running a plant. Nevertheless, it is concluded that a distillation plant with a vacuum induction furnace processing post-consumer scrap could operate economically in western Europe.

The history of small-scale or artisanal mining is briefly reviewed and current mining and processing methods are discussed, with particular reference to the use of amalgamation to extract Au and the associated health problems. Initiatives that have been carried out to secure and sustain the small-scale mining industry in Kyrgyzstan and Mongolia are described including the use of alternative extraction methods and the recycling of Hg using retorts. The associated training and information programmes are discussed. The use of Hg is illegal in both countries but the Mongolian authorities still allow training in the use of retorts, whereas the Kyrgyz authorities do not., The history of small-scale or artisanal mining is briefly reviewed and current mining and processing methods are discussed, with particular reference to the use of amalgamation to extract Au and the associated health problems. Initiatives that have been carried out to secure and sustain the small-scale mining industry in Kyrgyzstan and Mongolia are described including the use of alternative extraction methods and the recycling of Hg using retorts. The associated training and information programmes are discussed. The use of Hg is illegal in both countries but the Mongolian authorities still allow training in the use of retorts, whereas the Kyrgyz authorities do not.

The physical properties and characteristics of mercury and mercury vapour are presented and their impact on retort design and operation discussed. Components of the retort or vacuum distillation system are described in detail: the oven, controls, condensers, carbon absorber, vacuum pump, fugitive-emission controls and accessory equipment. Operational considerations include feed preparation, loading/unloading, cycle times and temperatures and industrial hygiene. Removal of other elements such as Cd, Se and As requires careful consideration of mineralogy, vapour pressure and operating temperature., The physical properties and characteristics of mercury and mercury vapour are presented and their impact on retort design and operation discussed. Components of the retort or vacuum distillation system are described in detail: the oven, controls, condensers, carbon absorber, vacuum pump, fugitive-emission controls and accessory equipment. Operational considerations include feed preparation, loading/unloading, cycle times and temperatures and industrial hygiene. Removal of other elements such as Cd, Se and As requires careful consideration of mineralogy, vapour pressure and operating temperature.