technologyComment of gold mine operation and refining (SE): OPEN PIT MINING: The ore is mined in four steps: drilling, blasting, loading and hauling. In the case of a surface mine, a pattern of holes is drilled in the pit and filled with explosives. The explosives are detonated in order to break up the ground so large shovels or front-end loaders can load it into haul trucks. ORE AND WASTE HAULAGE: The haul trucks transport the ore to various areas for processing. The grade and type of ore determine the processing method used. Higher-grade ores are taken to a mill. Lower grade ores are taken to leach pads. Some ores may be stockpiled for later processing. HEAP LEACHING: The ore is crushed or placed directly on lined leach pads where a dilute cyanide solution is applied to the surface of the heap. The solution percolates down through the ore, where it leaches the gold and flows to a central collection location. The solution is recovered in this closed system. The pregnant leach solution is fed to electrowinning cells and undergoes the same steps as described below from Electro-winning. ORE PROCESSING: Milling: The ore is fed into a series of grinding mills where steel balls grind the ore to a fine slurry or powder. Oxidization and leaching: Some types of ore require further processing before gold is recovered. In this case, the slurry is pressure-oxidized in an autoclave before going to the leaching tanks or a dry powder is fed through a roaster in which it is oxidized using heat before being sent to the leaching tanks as a slurry. The slurry is thickened and runs through a series of leaching tanks. The gold in the slurry adheres to carbon in the tanks. Stripping: The carbon is then moved into a stripping vessel where the gold is removed from the carbon by pumping a hot caustic solution through the carbon. The carbon is later recycled. Electro-winning: The gold-bearing solution is pumped through electro-winning cells or through a zinc precipitation circuit where the gold is recovered from the solution. Smelting: The gold is then melted in a furnace at about 1’064°C and poured into moulds, creating doré bars. Doré bars are unrefined gold bullion bars containing between 60% and 95% gold. References: Newmont (2004) How gold is mined. Newmont. Retrieved from http://www.newmont.com/en/gold/howmined/index.asp technologyComment of primary lead production from concentrate (GLO): There are two basic pyrometallurgical processes available for the production of lead from lead or mixed lead-zinc-sulphide concentrates: sinter oxidation / blast furnace reduction route or Direct Smelting Reduction Processes. Both processes are followed by a refining step to produce the final product with the required purity, and may also be used for concentrates mixed with secondary raw materials. SINTER OXIDATION / BLAST FURNACE REDUCTION: The sinter oxidation / blast furnace reduction involves two steps: 1) A sintering oxidative roast to remove sulphur with production of PbO; and 2) Blast furnace reduction of the sinter product. The objective of sintering lead concentrates is to remove as much sulphur as possible from the galena and the accompanying iron, zinc, and copper sulphides, while producing lump agglomerate with appropriate properties for subsequent reduction in the blast furnace (a type of a shaft furnace). As raw material feed, lead concentrates are blended with recycled sinter fines, secondary material and other process materials and pelletised in rotating drums. Pellets are fed onto sinter machine and ignited. The burning pellets are conveyed over a series of wind-boxes through which air is blown. Sulphur is oxidised to sulphur dioxide and the reaction generates enough heat to fuse and agglomerate the pellets. Sinter is charged to the blast furnace with metallurgical coke. Air and/or oxygen enriched air is injected and reacts with the coke to produce carbon monoxide. This generates sufficient heat to melt the charge. The gangue content of the furnace charge combines with the added fluxes or reagents to form a slag. For smelting bulk lead-zinc-concentrates and secondary material, frequently the Imperial Smelting Furnace is used. Here, hot sinter and pre-heated coke as well as hot briquettes are charged. Hot air is injected. The reduction of the metal oxides not only produces lead and slag but also zinc, which is volatile at the furnace operating temperature and passes out of the ISF with the furnace off-gases. The gases also contain some cadmium and lead. The furnace gases pass through a splash condenser in which a shower of molten lead quenches them and the metals are absorbed into the liquid lead, the zinc is refined by distillation. DIRECT SMELTING REDUCTION: The Direct Smelting Reduction Process does not carry out the sintering stage separately. Lead sulphide concentrates and secondary materials are charged directly to a furnace and are then melted and oxidised. Sulphur dioxide is formed and is collected, cleaned and converted to sulphuric acid. Carbon (coke or gas) and fluxing agents are added to the molten charge and lead oxide is reduced to lead, a slag is formed. Some zinc and cadmium are “fumed” off in the furnace, their oxides are captured in the abatement plant and recovered. Several processes are used for direct smelting of lead concentrates and some secondary material to produce crude lead and slag. Bath smelting processes are used: the ISA Smelt/Ausmelt furnaces (sometimes in combination with blast furnaces), Kaldo (TBRC) and QSL integrated processes are used in EU and Worldwide. The Kivcet integrated process is also used and is a flash smelting process. The ISA Smelt/Ausmelt furnaces and the QSL take moist, pelletised feed and the Kaldo and Kivcet use dried feed. REFINING: Lead bullion may contain varying amounts of copper, silver, bismuth, antimony, arsenic and tin. Lead recovered from secondary sources may contain similar impurities, but generally antimony and calcium dominate. There are two methods of refining crude lead: electrolytic refining and pyrometallurgical refining. Electrolytic refining uses anodes of de-copperised lead bullion and starter cathodes of pure lead. This is a high-cost process and is used infrequently. A pyrometallurgical refinery consists of a series of kettles, which are indirectly heated by oil or gas. Over a series of separation processes impurities and metal values are separated from the lead bouillon. Overall waste: The production of metals is related to the generation of several by-products, residues and wastes, which are also listed in the European Waste Catalogue (Council Decision 94/3/EEC). The ISF or direct smelting furnaces also are significant sources of solid slag. This slag has been subjected to high temperatures and generally contains low levels of leachable metals, consequently it may be used in construction. Solid residues also arise as the result of the treatment of liquid effluents. The main waste stream is gypsum waste (CaSO4) and metal hydroxides that are produced at the wastewater neutralisation plant. These wastes are considered to be a cross-media effect of these treatment techniques but many are recycled to pyrometallurgical process to recover the metals. Dust or sludge from the treatment of gases are used as raw materials for the production of other metals such as Ge, Ga, In and As, etc or can be returned to the smelter or into the leach circuit for the recovery of lead and zinc. Hg/Se residues arise at the pre-treatment of mercury or selenium streams from the gas cleaning stage. This solid waste stream amounts to approximately 40 - 120 t/y in a typical plant. Hg and Se can be recovered from these residues depending on the market for these metals. Overall emissions: The main emissions to air from zinc and lead production are sulphur dioxide, other sulphur compounds and acid mists; nitrogen oxides and other nitrogen compounds, metals and their compounds; dust; VOC and dioxins. Other pollutants are considered to be of negligible importance for the industry, partly because they are not present in the production process and partly because they are immediately neutralised (e.g. chlorine) or occur in very low concentrations. Emissions are to a large extent bound to dust (except cadmium, arsenic and mercury that can be present in the vapour phase). Metals and their compounds and materials in suspension are the main pollutants emitted to water. The metals concerned are Zn, Cd, Pb, Hg, Se, Cu, Ni, As, Co and Cr. Other significant substances are fluorides, chlorides and sulphates. Wastewater from the gas cleaning of the smelter and fluid-bed roasting stages are the most important sources. References: Sutherland C. A., Milner E. F., Kerby R. C., Teindl H. and Melin A. (1997) Lead. In: Ullmann's encyclopedia of industrial chemistry (ed. Anonymous). 5th edition on CD-ROM Edition. Wiley & Sons, London. IPPC (2001) Integrated Pollution Prevention and Control (IPPC); Reference Document on Best Available Techniques in the Non Ferrous Metals Industries. European Commission. Retrieved from http://www.jrc.es/pub/english.cgi/ 0/733169 technologyComment of primary zinc production from concentrate (RoW): The technological representativeness of this dataset is considered to be high as smelting methods for zinc are consistent in all regions. Refined zinc produced pyro-metallurgically represents less than 5% of global zinc production and less than 2% of this dataset. Electrometallurgical Smelting The main unit processes for electrometallurgical zinc smelting are roasting, leaching, purification, electrolysis, and melting. In both electrometallurgical and pyro-metallurgical zinc production routes, the first step is to remove the sulfur from the concentrate. Roasting or sintering achieves this. The concentrate is heated in a furnace with operating temperature above 900 °C (exothermic, autogenous process) to convert the zinc sulfide to calcine (zinc oxide). Simultaneously, sulfur reacts with oxygen to produce sulfur dioxide, which is subsequently converted to sulfuric acid in acid plants, usually located with zinc-smelting facilities. During the leaching process, the calcine is dissolved in dilute sulfuric acid solution (re-circulated back from the electrolysis cells) to produce aqueous zinc sulfate solution. The iron impurities dissolve as well and are precipitated out as jarosite or goethite in the presence of calcine and possibly ammonia. Jarosite and goethite are usually disposed of in tailing ponds. Adding zinc dust to the zinc sulfate solution facilitates purification. The purification of leachate leads to precipitation of cadmium, copper, and cobalt as metals. In electrolysis, the purified solution is electrolyzed between lead alloy anodes and aluminum cathodes. The high-purity zinc deposited on aluminum cathodes is stripped off, dried, melted, and cast into SHG zinc ingots (99.99 % zinc). Pyro-metallurgical Smelting The pyro-metallurgical smelting process is based on the reduction of zinc and lead oxides into metal with carbon in an imperial smelting furnace. The sinter, along with pre-heated coke, is charged from the top of the furnace and injected from below with pre-heated air. This ensures that temperature in the center of the furnace remains in the range of 1000-1500 °C. The coke is converted to carbon monoxide, and zinc and lead oxides are reduced to metallic zinc and lead. The liquid lead bullion is collected at the bottom of the furnace along with other metal impurities (copper, silver, and gold). Zinc in vapor form is collected from the top of the furnace along with other gases. Zinc vapor is then condensed into liquid zinc. The lead and cadmium impurities in zinc bullion are removed through a distillation process. The imperial smelting process is an energy-intensive process and produces zinc of lower purity than the electrometallurgical process. technologyComment of treatment of electronics scrap, metals recovery in copper smelter (SE, RoW): Conversion of Copper in a Kaldo Converter and treatment in converter aisle. technologyComment of treatment of scrap lead acid battery, remelting (RoW): The referred operation uses a shaft furnace with post combustion, which is the usual technology for secondary smelters. technologyComment of treatment of scrap lead acid battery, remelting (RER): The referred operation uses a shaft furnace with post combustion, which is the usual technology for secondary smelters. Typically this technology produces 5000 t / a sulphuric acid (15% concentration), 25’000 t lead bullion (98% Pb), 1200 t / a slags (1% Pb) and 3000 t / a raw lead matte (10% Pb) to be shipped to primary smelters. Overall Pb yield is typically 98.8% at the plant level and 99.8% after reworking the matte. The operation treats junk batteries and plates but also lead cable sheathing, drosses and sludges, leaded glass and balancing weights. From this feed it manufactures mainly antimonial lead up to 10% Sb, calcium-aluminium lead alloys with or without tin and soft lead with low and high copper content. All these products are the result of a refining and alloying step to meet the compliance with the designations desired. The following by products are reused in the process: fine dust, slag, and sulfuric acid. References: Quirijnen L. (1999) How to implement efficient local lead-acid battery recycling. In: Journal of Power Sources, 78(1-2), pp. 267-269.
technologyComment of gold mine operation and refining (SE): OPEN PIT MINING: The ore is mined in four steps: drilling, blasting, loading and hauling. In the case of a surface mine, a pattern of holes is drilled in the pit and filled with explosives. The explosives are detonated in order to break up the ground so large shovels or front-end loaders can load it into haul trucks. ORE AND WASTE HAULAGE: The haul trucks transport the ore to various areas for processing. The grade and type of ore determine the processing method used. Higher-grade ores are taken to a mill. Lower grade ores are taken to leach pads. Some ores may be stockpiled for later processing. HEAP LEACHING: The ore is crushed or placed directly on lined leach pads where a dilute cyanide solution is applied to the surface of the heap. The solution percolates down through the ore, where it leaches the gold and flows to a central collection location. The solution is recovered in this closed system. The pregnant leach solution is fed to electrowinning cells and undergoes the same steps as described below from Electro-winning. ORE PROCESSING: Milling: The ore is fed into a series of grinding mills where steel balls grind the ore to a fine slurry or powder. Oxidization and leaching: Some types of ore require further processing before gold is recovered. In this case, the slurry is pressure-oxidized in an autoclave before going to the leaching tanks or a dry powder is fed through a roaster in which it is oxidized using heat before being sent to the leaching tanks as a slurry. The slurry is thickened and runs through a series of leaching tanks. The gold in the slurry adheres to carbon in the tanks. Stripping: The carbon is then moved into a stripping vessel where the gold is removed from the carbon by pumping a hot caustic solution through the carbon. The carbon is later recycled. Electro-winning: The gold-bearing solution is pumped through electro-winning cells or through a zinc precipitation circuit where the gold is recovered from the solution. Smelting: The gold is then melted in a furnace at about 1’064°C and poured into moulds, creating doré bars. Doré bars are unrefined gold bullion bars containing between 60% and 95% gold. References: Newmont (2004) How gold is mined. Newmont. Retrieved from http://www.newmont.com/en/gold/howmined/index.asp technologyComment of primary zinc production from concentrate (CA-QC): Hydrometallurgical process Sulphide concentrates are roasted first in fluidized bed roasters to produce zinc oxide (calcine) and sulphur dioxide. Roasting is an exothermic process and no additional fuel is used to sustain the reaction, the heat generated is recovered to produce steam. Calcine is then sent to the leaching step. Roaster gases are treated in hot electrostatics precipitators to remove dust. The remaining dust and volatile metals such as mercury and selenium are removed in the wet section of the acid plant through a cooling tour, a mist precipitator and a mercury tower (Boliden mercury removal processs). The sulphur dioxide is then converted to sulphuric acid in a conventional recovery system (converted and absorbing tower). Leaching of the calcine is carried out in a number of successive stages using a gradually increasing strength of hot sulphuric acid. The initial stages dissolve the major part of the zinc oxide and the other stages dissolve the zinc ferrite (ZnO.Fe2O3) and convert iron into Jarosite (sodium Jarosite). Zinc sulfate (ZnSO4) entering the electrolysis stage produce electrolyte (H2SO4) that is returned to leaching plant. Other metals are also dissolved during the process and are removed after leaching. Iron is the major impurity, which is precipitated in the form of Jarosite. Overall waste: The production of metals is related to the generation of several by-products, residues and wastes. Relatively large quantities of iron based solids, depending on the iron content, are generated by the leaching process (6.14E-1 kg Jarosite/kg zinc). Cement is added to the Jarosite to produce Jarofix (an inert waste). Solid residues also arise as the result of the liquid effluents treatment. The main waste stream is gypsum (CaSO4) and metal hydroxides that are produced at the wastewater neutralization plant. Mercury and selenium residues arise from the weak acid bleed treatment from the acid plant. Selenium can be recovered from these residues depending on the market demand for this metal. Overall emissions: The emissions to air can either be stack emissions or fugitive emissions. Stack emissions are normally monitored continuously (SO2) or periodically (other emissions) and reported. The main emissions to air from zinc production are sulphur dioxide (SO2) and particulate matters including metals. Main emissions to water are metals and their compounds. The monitored metals are zinc, cadmium, lead, mercury, selenium, copper and arsenic. technologyComment of primary zinc production from concentrate (RoW): The technological representativeness of this dataset is considered to be high as smelting methods for zinc are consistent in all regions. Refined zinc produced pyro-metallurgically represents less than 5% of global zinc production and less than 2% of this dataset. Electrometallurgical Smelting The main unit processes for electrometallurgical zinc smelting are roasting, leaching, purification, electrolysis, and melting. In both electrometallurgical and pyro-metallurgical zinc production routes, the first step is to remove the sulfur from the concentrate. Roasting or sintering achieves this. The concentrate is heated in a furnace with operating temperature above 900 °C (exothermic, autogenous process) to convert the zinc sulfide to calcine (zinc oxide). Simultaneously, sulfur reacts with oxygen to produce sulfur dioxide, which is subsequently converted to sulfuric acid in acid plants, usually located with zinc-smelting facilities. During the leaching process, the calcine is dissolved in dilute sulfuric acid solution (re-circulated back from the electrolysis cells) to produce aqueous zinc sulfate solution. The iron impurities dissolve as well and are precipitated out as jarosite or goethite in the presence of calcine and possibly ammonia. Jarosite and goethite are usually disposed of in tailing ponds. Adding zinc dust to the zinc sulfate solution facilitates purification. The purification of leachate leads to precipitation of cadmium, copper, and cobalt as metals. In electrolysis, the purified solution is electrolyzed between lead alloy anodes and aluminum cathodes. The high-purity zinc deposited on aluminum cathodes is stripped off, dried, melted, and cast into SHG zinc ingots (99.99 % zinc). Pyro-metallurgical Smelting The pyro-metallurgical smelting process is based on the reduction of zinc and lead oxides into metal with carbon in an imperial smelting furnace. The sinter, along with pre-heated coke, is charged from the top of the furnace and injected from below with pre-heated air. This ensures that temperature in the center of the furnace remains in the range of 1000-1500 °C. The coke is converted to carbon monoxide, and zinc and lead oxides are reduced to metallic zinc and lead. The liquid lead bullion is collected at the bottom of the furnace along with other metal impurities (copper, silver, and gold). Zinc in vapor form is collected from the top of the furnace along with other gases. Zinc vapor is then condensed into liquid zinc. The lead and cadmium impurities in zinc bullion are removed through a distillation process. The imperial smelting process is an energy-intensive process and produces zinc of lower purity than the electrometallurgical process.
technologyComment of styrene production (RoW): Styrene is mainly produced by the dehydrogenation of ethylbenzene (EBS process) and via ethylbenzene hydroperoxide (POSM process) with propylene oxide as a by-product (James and Castor 2011). This dataset reflects only the dehydrogenation of ethylbenzene (EBS). Close to the entire production of ethylbenzene is produced via the alkylation of ethylene and benzene (Welch et al. 2005). This production route has been used since the mid-nineties (James and Castor 2011). Chemical reaction: C6H6 + C2H4 -> C8H10 C8H10 -> C8H8 + H2 The reaction from ethylbenzene to styrene is reversible. The reaction is endothermic with a heat delta of 600 degrees Celcius and 124.0 kJ/mol (James and Castor 2011). The production of styrene is mostly performed (ca. 75% of production), by running ethylbenzene (the input includes recycled ethylbenzene) through subsequent reactors / reactors beds. Steam is used to dehydrogenate the input product. Steam has been found to ensure a high yield, provide the necessary conditions for the reaction to happen and at the same time cleaning the used catalyst (James and Castor 2011). The use of a catalyst boosts the efficiency of the reaction, otherwise low temperature and low pressure are enough to ensure the reaction but with lower yield. Usual reaction conditions are 620 degrees Celsius combined with very low pressure, this ensures a yield between 88 and 95% (James and Castor 2011). According to James and Castor (2011) one of the most used catalyst for this reaction is composed by 84.3% iron (Fe2O3), 2.4% chromium (Cr2O3), and 13.3% potassium (K2CO3) (James and Castor 2011). The average lifespan of catalysts for this reaction is assumed to be 2 years (James and Castor 2011). The catalyst in not consider significant in terms of emissions for the reaction and it is therefore not included in this dataset and it is assumed to be taken into consideration in the input of chemical factory. The main source of information for the values for water (process and cooling), nitrogen and chemical factory is industry data from Gendorf. The values are a 5-year average of data (2011 - 2015) published by the Gendorf factory (Gendorf, 2016, Umwelterklärung, www.gendorf.de), (Gendorf, 2015, Umwelterklärung, www.gendorf.de), (Gendorf, 2014, Umwelterklärung, www.gendorf.de). The Gendorf factory is based in Germany, it produces a wide range of chemical substances. The factory produced 1657400 tonnes of chemical substances in the year 2015 (Gendorf, 2016, Umwelterklärung, www.gendorf.de) and 740000 tonnes of intermediate products. Reference(s): Hischier, R. (2005) Establishing Life Cycle Inventories of Chemicals Based on Differing Data Availability (9 pp). The International Journal of Life Cycle Assessment, Volume 10, Issue 1, pp 59–67. 10.1065/lca2004.10.181.7 Gendorf (2016) Umwelterklärung 2015, Werk Gendorf Industriepark, www.gendorf.de James, D.H. and Castor, W.M. 2011. Styrene. In Ullmann's Encyclopedia of Industrial Chemistry, Electronic Release, Vol.34, pp.529-544. Wiley-VCH, Weinheim. Welch, V.A. et al. 2005. Ethylbenzene. In Ullmann's Encyclopedia of Industrial Chemistry, Electronic Release, Vol.13, pp.451-464. Wiley-VCH, Weinheim. technologyComment of styrene production (RER): Styrene is mainly produced by the dehydrogenation of ethylbenzene (EBS process) and via ethylbenzene hydroperoxide (POSM process) with propylene oxide as a by-product (James and Castor 2011). This dataset reflects only the dehydrogenation of ethylbenzene (EBS). Close to the entire production of ethylbenzene is produced via the alkylation of ethylene and benzene (Welch et al. 2005). This production route has been used since the mid-nineties (James and Castor 2011). Chemical reaction: C6H6 + C2H4 -> C8H10 C8H10 -> C8H8 + H2 The reaction from ethylbenzene to styrene is reversible. The reaction is endothermic with a heat delta of 600 degrees Celcius and 124.0 kJ/mol (James and Castor 2011). The production of styrene is mostly performed (ca. 75% of production), by running ethylbenzene (the input includes recycled ethylbenzene) through subsequent reactors / reactors beds. Steam is used to dehydrogenate the input product. Steam has been found to ensure a high yield, provide the necessary conditions for the reaction to happen and at the same time cleaning the used catalyst (James and Castor 2011). The use of a catalyst boosts the efficiency of the reaction, otherwise low temperature and low pressure are enough to ensure the reaction but with lower yield. Usual reaction conditions are 620 degrees Celsius combined with very low pressure, this ensures a yield between 88 and 95% (James and Castor 2011). According to James and Castor (2011) one of the most used catalyst for this reaction is composed by 84.3% iron (Fe2O3), 2.4% chromium (Cr2O3), and 13.3% potassium (K2CO3) (James and Castor 2011). The average lifespan of catalysts for this reaction is assumed to be 2 years (James and Castor 2011). The catalyst in not consider significant in terms of emissions for the reaction and it is therefore not included in this dataset and it is assumed to be taken into consideration in the input of chemical factory. The main source of information for the values for water (process and cooling), nitrogen and chemical factory is industry data from Gendorf. The values are a 5-year average of data (2011 - 2015) published by the Gendorf factory (Gendorf, 2016, Umwelterklärung, www.gendorf.de), (Gendorf, 2015, Umwelterklärung, www.gendorf.de), (Gendorf, 2014, Umwelterklärung, www.gendorf.de). The Gendorf factory is based in Germany, it produces a wide range of chemical substances. The factory produced 1657400 tonnes of chemical substances in the year 2015 (Gendorf, 2016, Umwelterklärung, www.gendorf.de) and 740000 tonnes of intermediate products. Reference(s): Hischier, R. (2005) Establishing Life Cycle Inventories of Chemicals Based on Differing Data Availability (9 pp). The International Journal of Life Cycle Assessment, Volume 10, Issue 1, pp 59–67. 10.1065/lca2004.10.181.7 Gendorf (2016) Umwelterklärung 2015, Werk Gendorf Industriepark, www.gendorf.de James, D.H. and Castor, W.M. 2011. Styrene. In Ullmann's Encyclopedia of Industrial Chemistry, Electronic Release, Vol.34, pp.529-544. Wiley-VCH, Weinheim. Welch, V.A. et al. 2005. Ethylbenzene. In Ullmann's Encyclopedia of Industrial Chemistry, Electronic Release, Vol.13, pp.451-464. Wiley-VCH, Weinheim. Certain data points from a company survey by PlasticsEurope (three companies and four production sites).
technologyComment of manganese production (RER): The metal is won by electrolysis (25%) and electrothermic processes (75%). ELECTROLYSIS OF AQUEOUS MANGANESE SALTS The production of manganese metal by the electrolysis of aqueous manganese salts requires at first a milling of the manganese ore. Milling increases the active surface and ensures sufficient reactivity in both the reduction and the subsequent leaching steps. After milling the manganese ore is fed to a rotary kiln where the reduction and calcination takes place. This process is carried out at about 850 - 1000 ºC in a reducing atmosphere. As a reducing agent, several carbon sources can be used e.g. anthracite, coal, charcoal and hydrocarbon oil or natural gas. The cal-cined ore needs to be cooled below 100 ºC to avoid a further re-oxidation. The subsequent leaching process is carried out with recycled electrolyte, mainly sulphuric acid. After leaching and filtration the iron content is removed from the solution by oxidative precipitation and the nickel and cobalt are removed by sulphide precipitation. The purified electrolyte is then treated with SO2 in order to ensure plating of γ-Mn during electrolysis. Electrolysis is carried out in diaphragm cells. The cathode is normally made of stainless steel or titanium. For the anode lead-calcium or lead-silver alloy can be used. After an appropriate reaction time the cathodes are removed from the electrolysis bath. The manganese that is deposited on the cathode starter-sheet is stripped off mechanically and then washed and dried. The metal is crushed to produce metal flakes or powder or granulated, depending on the end use. ELECTROTHERMAL DECOMPOSITION OF MANGANESE ORES The electrothermal process is the second important process to produce manganese metal in an industrial scale. The electrothermal process takes place as a multistage process. In the first stage manganese ore is smelted with only a small amount of reductant in order to reduce mostly the iron oxide. This produces a low-grade ferro-manganese and a slag that is rich in Mn-oxide. The slag is then smelted in the second stage with silicon to produce silicomanganese. The molten silicomanganese can be treated with liquid slag from the fist stage to obtain relatively pure manganese metal. For the last step a ladle or shaking ladle can be used. The manganese metal produced by the electrothermal process contains up to 98% of Mn. Overall emissions and waste: Emissions to air consist of dust and fume emissions from smelting, hard metal and carbide production; Other emissions to air are ammonia (NH3), acid fume (HCl), hydrogen fluoride (HF), VOC and heavy metals. Effluents are composed of overflow water from wet scrubbing systems, wastewater from slag and metal granulation, and blow down from cooling water cycles. Waste includes dust, fume, sludge and slag. References: Wellbeloved D. B., Craven P. M. and Waudby J. W. (1997) Manganese and Manganese Alloys. In: Ullmann's encyclopedia of industrial chemistry (ed. Anonymous). 5th edition on CD-ROM Edition. Wiley & Sons, London. IPPC (2001) Integrated Pollution Prevention and Control (IPPC); Reference Document on Best Available Techniques in the Non Ferrous Metals Industries. European Commission. Retrieved from http://www.jrc.es/pub/english.cgi/ 0/733169 technologyComment of manganese production (RoW): The metal is won by electrolysis (assumption: 25%) and electrothermic processes (assumption: 75%). No detailed information available, mainly based on rough estimates. technologyComment of treatment of non-Fe-Co-metals, from used Li-ion battery, hydrometallurgical processing (GLO): The technique SX-EW is used mainly for oxide ores and supergene sulphide ores (i.e. ores not containing iron). It is assumed to be used for the treatment of the non-Fe-Co-metals fraction. The process includes a leaching stage followed by cementation or electro-winning. A general description of the process steps is given below. In the dump leaching step, copper is recovered from large quantities (millions of tonnes) of strip oxide ores with a very low grade. Dilute sulphuric acid is trickled through the material. Once the process starts it continues naturally if water and air are circulated through the heap. The time required is typically measured in years. Sulphur dioxide is emitted during such operations. Soluble copper is then recovered from drainage tunnels and ponds. Copper recovery rates vary from 30% to 70%. Cconsiderable amounts of sulphuric acid and leaching agents emit into water and air. No figures are currently available on the dimension of such emissions. After the solvent-solvent extraction, considerable amounts of leaching residues remain, which consist of undissolved minerals and the remainders of leaching chemicals. In the solution cleaning step occur precipitation of impurities and filtration or selective enrichment of copper by solvent extraction or ion exchange. The solvent extraction process comprises two steps: selective extraction of copper from an aqueous leach solution into an organic phase (extraction circuit) and the re-extraction or stripping of the copper into dilute sulphuric acid to give a solution suitable for electro winning (stripping circuit). In the separation step occurs precipitation of copper metal or copper compounds such as Cu2O, CuS, CuCl, CuI, CuCN, or CuSO4 • 5 H2O (crystallisation) Waste: Like in the pyrometallurgical step, considerable quantities of solid residuals are generated, which are mostly recycled within the process or sent to other specialists to recover any precious metals. Final residues generally comprise hydroxide filter cakes (iron hydroxide, 60% water, cat I industrial waste).
technologyComment of lubricating oil production (RER): A huge variety of different compositions are known under the name “lubricants” – actually, 5’000 to 10’000 different formulations are used to satisfy about 90% of the different lubricants applications. In terms of quantity, mineral oil components continue to be the most important ingredients. But more and more, derivatives of natural, harvestable raw materials from the oleo-chemical sector are finding their acceptance within the used substances. In 1999 around 37 Mt of lubricants have been consumed – thereof more than half in the automotive sector (56%), and another 29% as industrial lubricants. This amount is produced by around 1700 producers worldwide. Thereof, about 200 are vertically-integrated petroleum companies where lubricants are only a minor part of their profit. Nevertheless, less than 2% of all lubricant manufacturers are producing more than 60% of the total production volume. In case of the remaining 1500 companies, lubricants are their core business. In terms of the volume, base oils are the most important parts of lubricants. The rest is composed of additives. For this dataset, the additives are based on data published in Raimondi et al. (2012). imageUrlTagReplace8b52761e-ab96-49e0-a771-a229ae16ec10 The image above represents the typical yields of the different cuts from a conventional lubricating oil refining process To achieve base oils, a variety of different steps have to be done starting with the crude oil that is extracted until the right components are isolated. Different steps therefore are for example refining, distillation, de-asphalting, traditional refining process, solvent dewaxing or finishing. Additional steps that are often used are as well hydrogenation and hydrocracking operations. Based on the fact that a multitude of different processes are possible for the production of lubricants, the following choices are done for this dataset – with the aim to create a typical dataset for petrochemical lubricants – called “lubricants”: - Hydrocracking as basic technology for the extraction of the lubricant oils due to the fact that according to Bartels et al. (2003) more than 50% of the new manufacturing plants work with this principle. - Distillation and dewaxing as subsequent process steps to achieve high-quality base lubricant oils - Diesel as input due to the fact that these hydrocracker need low-sulphur oils. References: Bartels T., Bock W., Braun J., Busch C., Dresel W., Freiler C., Harperscheid M., Heckler R.-P., Hörner D., Kubicki F., Lingg G., Losch A., Luther R., Mang T., Noll S. and Omeis J. (2003) Lubricants and Lubrication. In: Ullmann's Encyclopedia of Industrial Chemistry, Sixth Edition, 2003 Electronic Release (ed. Häussinger P., Leitgeb P. and Schmücker B.), 6 th Electronic Release Edition. Wiley InterScience, New York, Online-Version under: http://www.mrw.interscience.wiley.com/ueic/ull_search_fs.html. Andrea Raimondi, Giorgia Girotti, Gian Andrea Blengini and Debora Fino (2012) LCA of petroleum-based lubricants: state of art and inclusion of additives. Int J Life Cycle Assess (2012) 17:987–996.
technologyComment of phenol production (RER): This dataset models the Hock process, which is the main process that is used for the production of phenol. In this process, cumene is transformed into phenol in two stages: (i) oxidation of the cumene, and (ii) cleavage into phenol and acetone. The oxidation happens in large reactors at a temperature of about 90-120°C and 0.5-0.7 MPa pressure. The whole reaction is autocatalytic and exothermic, releasing about 800 kJ per kilogram of cumene hydroperoxide to the environment by active cooling systems, mainly water. The second reaction – the cleavage – is an acid-catalyzed reaction, using almost exclusively sulphuric acid as catalyst. Two different ways are used within industry – called homogeneous phase (using 0.1-2% sulphuric acid) rsp. heterogeneous phase (40-45% sulphuric acid at a concentrate-acid ratio of 1:5). Also this second step is strongly exothermic – releasing ca. 1680 kJ per kilogram of cumene hydroperoxide cleaved. After the cleavage, further cleaning steps are used to achieve in the end a phenol purity of >99.9%. This includes neutralization and removing of sulphuric acid, followed by distillation processes. The overall yield of the production of phenol for this case here is assumed to be in the order of 95%. The inventory is based on stoechiometric calculations. The emissions to air (0.2 wt% of raw material input) and water were estimated using mass balance. Treatment of the wastewater in an internal wastewater treatment plant is assumed (elimination efficiency of 90% for C). References: Althaus H.-J., Chudacoff M., Hischier R., Jungbluth N., Osses M. and Primas A. (2007) Life Cycle Inventories of Chemicals. ecoinvent report No. 8, v2.0. EMPA Dübendorf, Swiss Centre for Life Cycle Inventories, Dübendorf, CH. technologyComment of phenol production, from cumene (RER): This process consists first in the production of cumene from the reaction of benzene and propylene. Cumene then reacts with oxygen to give phenol and acetone. For each kilogram of phenol produced, 0.63 kg of acetone are obtained. For the process 0.6 MJ/kg of electricity and 9.1 MJ/kg of steam are required per kg of phenol and 0.2 MJ/kg of electricity and 9.8 MJ/kg of steam required per kg of acetone (Saygin 2009). Chemical reaction: C9H12 + O2 -> C6H6O + C3H6O This inventory representing production of a particular chemical compound is at least partially based on a generic model on the production of chemicals. The data generated by this model have been improved by compound-specific data when available. The model on production of chemicals is using specific industry or literature data wherever possible and more generic data on chemical production processes to fill compound-specific data gaps when necessary. The basic principles of the model have been published in literature (Hischier 2005, Establishing Life Cycle Inventories of Chemicals Based on Differing Data Availability). The model has been updated and extended with newly available data from the chemical industry. In the model, unreacted fractions are treated in a waste treatment process, and emissions reported are after a waste treatment process that is included in the scope of this dataset. For volatile reactants, a small level of evaporation is assumed. Solvents and catalysts are mostly recycled in closed-loop systems within the scope of the dataset and reported flows are for losses from this system. The main source of information for the values for heat, electricity, water (process and cooling), nitrogen, chemical factory is industry data from Gendorf. The values are a 5-year average of data (2011 - 2015) published by the Gendorf factory (Gendorf, 2016, Umwelterklärung, www.gendorf.de), (Gendorf, 2015, Umwelterklärung, www.gendorf.de), (Gendorf, 2014, Umwelterklärung, www.gendorf.de). The Gendorf factory is based in Germany, it produces a wide range of chemical substances. The factory produced 1657400 tonnes of chemical substances in the year 2015 (Gendorf, 2016, Umwelterklärung, www.gendorf.de) and 740000 tonnes of intermediate products. Reference(s): Hischier, R. (2005) Establishing Life Cycle Inventories of Chemicals Based on Differing Data Availability (9 pp). The International Journal of Life Cycle Assessment, Volume 10, Issue 1, pp 59–67. 10.1065/lca2004.10.181.7 Gendorf (2016) Umwelterklärung 2015, Werk Gendorf Industriepark, www.gendorf.de Gallardo Hipolito, M. 2011. Life Cycle Assessment of platform chemicals from fossil and lignocellulosic biomass scenarios LCA of phenolic compounds, solvent, soft and hard plastic precursors. Master in Industrial Ecology. Norwegian University of Science and Technology Department of Energy and Process Engineering. Retrieved from: http://daim.idi.ntnu.no/masteroppgaver/006/6362/tittelside.pdf, accessed 6 January 2017 SRI consulting. In: Gallardo Hipolito, M. 2011. Life Cycle Assessment of platform chemicals from fossil and lignocellulosic biomass scenarios LCA of phenolic compounds, solvent, soft and hard plastic precursors. Master in Industrial Ecology. Norwegian University of Science and Technology Department of Energy and Process Engineering. Retrieved from: http://daim.idi.ntnu.no/masteroppgaver/006/6362/tittelside.pdf, accessed 6 January 2017 Gallardo Hipolito, M. 2011. Life Cycle Assessment of platform chemicals from fossil and lignocellulosic biomass scenarios LCA of phenolic compounds, solvent, soft and hard plastic precursors. Master in Industrial Ecology. Norwegian University of Science and Technology Department of Energy and Process Engineering. Retrieved from: http://e-archivo.uc3m.es/bitstream/handle/10016/14718/Life%20Cycle%20Assessment%20of%20platform%20chemicals%20from%20fossil%20and%20lignocelulose%20scenarios.%20Martin%20Gallardo.pdf?sequence=2, accessed 6 January 2017 Saygin, D. 2009. Chemical and Petrochemical Sector Potential of best practice technology and other measures for improving energy efficiency. IEA information paper. IEA/OECD. Retrieved from: https://www.iea.org/publications/freepublications/publication/chemical_petrochemical_sector.pdf, accessed 6 January 2017 For more information on the model please refer to the dedicate ecoinvent report, access it in the Report section of ecoQuery (http://www.ecoinvent.org/login-databases.html)
technologyComment of chromium production (RoW): Metallic chromium is produced by aluminothermic process (75%) and electroylsis of dissolved ferrochromium (25%) technologyComment of chromium production (RER): Metallic chromium is produced by aluminothermic process (75%) and electroylsis of dissolved ferrochromium (25%) ALUMINOTHERMIC PROCESS The thermic process uses aluminium as a reducing agent for chromium hydroxide. The charge is weighed and loaded into a bin, which is taken to an enclosed room to mix the contents. The firing pot is prepared by ramming refractory sand mixed with water around a central former. After ramming the firing pot, the inner surface is coated with a weak binder solution and dried under a gas fired hood before being transferred to the firing station. The raw material mix is automatically fed at a controlled rate into the firing pot, where the exothermic reaction takes place. When the metal has solidified following the reaction, the firing pot is removed and transferred by crane to a cooling conveyor. On removal from the cooling conveyor (by crane), the firing pot is placed on a stripping bogie for transferral to a stripping booth. Inside the closed booth, the pot casing is hoisted off the solidified metal/slag. The slag is separated from the Chromium metal “button” and sent to a despatch storage area. Water is used to reduce button temperature to below 100 ºC. After cooling the metal button is transferred to other departments on site for cleaning, breaking, crushing and grinding to achieve the desired product size. ELECTROLYTIC PROCESS In the electrolytic process normally high carbon ferrochrome is used as the feed material which is then converted into chromium alum by dissolution with sulphuric acid at temperatures at about 200 ºC. After several process steps using crystallisation filtration ageing, a second filtration and a clarifying operation the alum becomes the electrolyte for a diaphragm cell. Chromium is plated onto stainless steel cathodes until it attains a thickness of ca. 3 mm. The process is very sensitive. The additional de-gassing (heating at 420 °C) stage is necessary because the carbon content of the electrolytic chromium is sometimes too high for further industrial applications. The cooled chromium metal is fragmented with a breaker prior to crushing and drumming. The generated slag can be reused as refractory lining or sold as abrasive or refractory material. Overall emissions and waste: Emissions to air consist of dust and fume emissions from smelting, hard metal and carbide production; other emissions to air are ammonia (NH3), acid fume (HCl), hydrogen fluoride (HF), VOC’s and heavy metals. Emissions to water are overflow water from wet scrubbing systems, wastewater from slag and metal granulation, and blow down from cooling water cycles. Solid waste is composed of dust, fume and sludge, and slag. References: IPPC (2001) Integrated Pollution Prevention and Control (IPPC); Reference Document on Best Available Techniques in the Non Ferrous Metals Industries. European Commission. Retrieved from http://www.jrc.es/pub/english.cgi/ 0/733169
technologyComment of platinum group metal mine operation, ore with high palladium content (RU): imageUrlTagReplace6250302f-4c86-4605-a56f-03197a7811f2 technologyComment of platinum group metal, extraction and refinery operations (ZA): The ores from the different ore bodies are processed in concentrators where a PGM concentrate is produced with a tailing by product. The PGM base metal concentrate product from the different concentrators processing the different ores are blended during the smelting phase to balance the sulphur content in the final matte product. Smelter operators also carry out toll smelting from third part concentrators. The smelter product is send to the Base metal refinery where the PGMs are separated from the Base Metals. Precious metal refinery is carried out on PGM concentrate from the Base metal refinery to split the PGMs into individual metal products. Water analyses measurements for Anglo Platinum obtained from literature (Slatter et.al, 2009). Mudd, G., 2010. Platinum group metals: a unique case study in the sustainability of mineral resources, in: The 4th International Platinum Conference, Platinum in Transition “Boom or Bust.” Water share between MC and EC from Mudd (2010). Mudd, G., 2010. Platinum group metals: a unique case study in the sustainability of mineral resources, in: The 4th International Platinum Conference, Platinum in Transition “Boom or Bust.” technologyComment of treatment of automobile catalyst (RoW): After collection and transportation to the intermediary dealer, the scrap is ground in a mill. The resulting material is fed to specialised refineries. The metallurgical step consists of an arc-furnace. Same refining process as in primary production assumed (selective precipitation) technologyComment of treatment of automobile catalyst (RER): The production process consists of three steps: Collection, Beneficiation and Refining. COLLECTION: Spoiled automotive catalysts are bought by specialised enterprises from different origins. Part of it originates from scrap dealer recycling end-of-life cars. Further more during the cars operating phase, defective catalysts are exchanged in garages. The third sources is the production waste, i. e. defective catalysts which do not reach market. In most cases, there are fix agreements between the different supplier and the intermediary trade. Although the trade with PGM containing scrap is risky. Motor car manufacturer built up their own internal recycling systems with their contractor garages and gained access to exchanged catalysts. Emissions: Emissions during collection are gases from transportation and dust from dismantling. Also in this step the combustion leads to emissions of SO2. No serious water emissions are reported. BENEFICIATION: The catalysts are dismantled and then sold to refining companies. Refineries too have long-term contracts with the intermediary trade. Emissions: Emissions during beneficiation are gases from transportation and dust from dismantling. Also in this step the combustion leads to emissions of SO2. No serious water emissions are reported. REFINING: The scrap first is shredded and then pyrometallurgicaly processed: The scrap is smelted in an electric arc furnace, and the ceramic wafer is slagged. The PGMs are concentrated in the collector metal, usually copper. Low-content PGM scrap is often smelted together with other non-ferrous metal matte. This is cheap, but effects a high loss in PGM. The collector matte from the furnace then is treated hydrometallurgically by re-precipitation. In this step usually production scrap from other industries (glass, chemical laboratories) is joined. The overall PGM-yield is 98 % for platinum and 85 % for rhodium. Emissions: Dust and metals are generally emitted from incinerators and furnaces. VOC can be emitted from solvent extraction processes, while organic compounds, namely dioxins, can be emitted from smelting stages resulting from the poor combustion of oil and plastic in the feed material. All these emissions are subject to abatement technologies and controlling. Effluents from refining contain considerable amounts of metals and organic substances. Waste: Solid residues from pyrometallurgical step are usually re-used in copper facilities, final residues generally comprise hydroxide filter cakes. References: Hagelücken C. (2001b) Die Märkte der Katalysatormetalle Platin, Palladium und Rhodium. In: Autoabgaskatalysatoren, Vol. 612. pp. 95-115. Expert Verlag, Renningen. Online-Version under: http://www.dmc-2.de/pmc_eng/Veroeffentlichungen_2/Die%20M%C3%A4rkte%20der%20Katalysatormetalle%20Pt%20Pd%20Rh.pdf.
technologyComment of processing of anode slime from electrorefining of copper, anode (GLO): Based on typical current technology. Anode slime treatment by pressure leaching and top blown rotary converter. Production of Silver by Möbius Electrolysis, Gold by Wohlwill electrolysis, copper telluride cement and crude selenium to further processing. technologyComment of selenium production (RER, RoW): Production from selenium is based on simplified roasting process with sodium carbonate. The inventory is based on stoechiometric calculations, according to the following equations: 2 X-Se + 2 Na2CO3 + 3 CO2 -> 2 Na2O4Se + 2 CO2 + 2 X (with X = compounds that were connected to Se - e.g. Cu2, CuAg, ....) 2 Na2O4Se + 4 HCl -> 2 H2O3Se + 4 NaCl + O2 2 H2O3Se + 2 SO2 -> 2 Se + 2 H2SO4 + O2 A surplus input of 25% is assumed. The air emissions occurring from the process are estimated to 0.2% of the raw material input. The remaining amount of unreacted raw materials is assumed to leave the production process to 95% as a solid waste and to 5% in the wastewater. Further it is assumed that this wastewater is treated in an internal wastewater plant. The carbonate is dissolved in the water and not shown anymore in the dataset. Sodium and chloride are assumed to be neutralized within the waste water treatment plant, leading to emissions of Cl- and Na+ in the water outflow. Sodium dioxide will be reacted into sulphuric acid and therefore leads to emissions of SO42- in the water outflow.
technologyComment of carbon black production (GLO): The most important production process used nowadays is the oil-furnace process – other processes like e.g. thermal or acetylene carbon black processes are only of minor interests and therefore not further examined within this study here. The oil-furnace process is, according to Voll and Kleinschmit (2010) and Dannenberg and Paquin (2000) a partial combustion process of liquid aromatic residual hydrocarbons. The principle is to atomize the feedstock into the reactor, where it is decomposed into carbon black and hydrogen due to the fact that the oxygen available is not sufficient for a combustion of all the input. The reactor temperature is in the order of 1200 to 1900 °C, achieved through the combustion of natural gas and of the unreacted feedstock. After the decomposition, a fast quenching has to be done to avoid the loss by reaction of carbon black with carbon dioxide and water. The further processing consists mainly of drying and separation from other substances like tail gases, through a filter system. This dataset describes the production of carbon black with the oil-furnace process, using natural gas as further energy input. The inventory is based on literature information about two different types of carbon black, as well as estimations based on industrial data. The emission amount is estimated while the composition is based on literature. References: Voll, M. and Kleinschmit, P. 2010. Carbon, 6. Carbon Black. Ullmann's Encyclopedia of Industrial Chemistry. Dannenberg E. M. and Paquin L. (2000) Carbon Black. In: Kirk-Othmer Encyclopedia of Chemical Technology, Fourth Edition, Electronic Release, 4 th Electronic Release Edition. Wiley InterScience, New York, Online-Version under: http://www.mrw.interscience.wiley.com/kirk.