Description: technologyComment of rare earth oxides production, from rare earth oxide concentrate, 70% REO (CN-SC): This dataset refers to the separation (hydrochloric acid leaching) and refining (metallothermic reduction) process used in order to produce high-purity rare earth oxides (REO) from REO concentrate, 70% beneficiated. ''The concentrate is calcined at temperatures up to 600ºC to oxidize carbonaceous material. Then HCl leaching, alkaline treatment, and second HCl leaching is performed to produce a relatively pure rare earth chloride (95% REO). Hydrochloric acid leaching in Sichuan is capable of separating and recovering the majority of cerium oxide (CeO) in a short process. For this dataset, the entire quantity of Ce (50% cerium dioxide [CeO2]/REO) is assumed to be produced here as CeO2 with a grade of 98% REO. Foreground carbon dioxide CO2 emissions were calculated from chemical reactions of calcining beneficiated ores. Then metallothermic reduction produces the purest rare earth metals (99.99%) and is most common for heavy rare earths. The metals volatilize, are collected, and then condensed at temperatures of 300 to 400°C (Chinese Ministryof Environmental Protection 2009).'' Source: Lee, J. C. K., & Wen, Z. (2017). Rare Earths from Mines to Metals: Comparing Environmental Impacts from China's Main Production Pathways. Journal of Industrial Ecology, 21(5), 1277-1290. doi:10.1111/jiec.12491 technologyComment of sodium chloride production, powder (RER, RoW): For the production of dry salt, three different types of sodium chloride production methods can be distinguished namely, underground mining of halite deposits, solution mining with mechanical evaporation and solar evaporation. Their respective products are rock salt, evaporated salt and solar salt: - Underground mining: The main characteristic of this technique is the fact that salt is not dissolved during the whole process. Instead underground halite deposits are mined with traditional techniques like undercutting, drilling and blasting or with huge mining machines with cutting heads. In a second step, the salt is crushed and screened to the desired size and then hoisted to the surface. - Solution mining and mechanical evaporation: In this case, water is injected in a salt deposit, usually in about 150 to 500 m depth. The dissolution of the halite or salt deposits forms a cavern filled with brine. This brine is then pumped from the cavern back to the surface and transported to either an evaporation plant for the production of evaporated salt or transported directly to a chemical processing plant, e.g. a chlor-alkali plant. - Solar evaporation: In this case salt is produced with the aid of the sun and wind out of seawater or natural brine in lakes. Within a chain of ponds, water is evaporated by sun until salt crystallizes on the floor of the ponds. Due to their natural process drivers, such plants must be located in areas with only small amounts of rain and high evaporation rates - e.g. in the Mediterranean area where the rate between evaporation and rainfall is 3:1, or in Australia, where even a ratio up to 15:1 can be found. There are some impurities due to the fact that seawater contains not only sodium chloride. That leads to impurities of calcium and magnesium sulfate as well as magnesium chloride. With the aid of clean brine from dissolved fine salt, these impurities are washed out. As a fourth form on the market, the so-called 'salt in brine' may be found, which is especially used for the production of different chemicals. In this case, the solution mining technique without an evaporation step afterwards is used. This dataset represents the production of dry sodium chloride by underground mining (51%) and by solution mining (49%) with modern solution mining technology (thermo compressing technology). 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.
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text_type: Report,
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Comment: This is a market activity. Each market represents the consumption mix of a product in a given geography, connecting suppliers with consumers of the same product in the same geographical area. Markets group the producers and also the imports of the product (if relevant) within the same geographical area. They also account for transport to the consumer and for the losses during that process, when relevant. This is the market for 'sodium chloride, powder', in the Global geography. Transport from producers to consumers of this product in the geography covered by the market is included. 'sodium chloride, powder' is an inorganic substance with a CAS no. : 007647-14-5. It is called 'sodium chloride' under IUPAC naming and its molecular formula is: NaCl. It is solid under normal conditions of temperature and pressure and appears as a white crystalline solid. It is modelled as a pure substance. On a consumer level, is used in the following products: cosmetics and personal care products, fertilisers, anti-freeze products, perfumes and fragrances and water treatment chemicals. On industrial sites, the substance is used for the manufacture of products in the following sectors: formulation of mixtures and/or re-packaging, textile, leather or fur, pulp, paper and paper products, chemicals, mineral products (e.g. plasters, cement) and electrical, electronic and optical equipment. This market is supplied by the following activities with the given share: sodium chloride production, powder, RER: 0.173758639167175 sodium chloride production, powder, RoW: 0.824854229609694 rare earth oxides production, from rare earth oxide concentrate, 70% REO, CN-SC: 0.00138713122313065 generalComment of rare earth oxides production, from rare earth oxide concentrate, 70% REO (CN-SC): For the separation and refining of rare earth oxides in the Sichuan region of China. This dataset is based on the following publication: Arshi, P. S., Vahidi, E., & Zhao, F. (2018). Behind the Scenes of Clean Energy: The Environmental Footprint of Rare Earth Products. ACS Sustainable Chemistry & Engineering, 6(3), 3311-3320. doi:10.1021/acssuschemeng.7b03484 and the critical materials life cycle assessment tool (CMLCAT) of Arshi et al. (2018), provided by F. Zhao from Purdue University. Specific modifications were made in order to make the dataset more transparent. Background: Metals are produced as part of a complex, highly interconnected and interdependent system, with many desirable but scarce/critical metals recovered as by-products during the production of one or more ‘host’ metal(s). Currently, mining and processing of rare earth elements is predominantly carried out in China, where they are extracted mainly via open pit mining of bastnäsite and/or monazite deposits or the leaching of ion-adsorption clays. Modelling approach: This dataset was created using the critical materials life cycle assessment tool (CMLCAT) of Arshi et al. (2018). generalComment of sodium chloride production, powder (RER, RoW): This dataset represents the production of 1 kg of sodium chloride. Sodium chloride (NaCl) forms odorless cubic crystals. Depending on its degree of purity, the color varies between colorless when pure and white to gray when in the form of rock salt. Sodium chloride has a huge variety of different uses. For example, salt is today the largest mineral feedstock consumed by the chemical industry. It is primarily used as a chemical feedstock for the production of chlorine and caustic soda in the chlor-alkali industry. Salt is also needed for the production of sodium chlorate and metallic sodium by electrolysis, and for the production of sodium sulfate and hydrochloric acid by reacting sodium chloride with sulfuric acid. Another very important area where sodium chloride is used is the human and animal nutrition, since all animals, humans included, need both sodium and chloride. Other relevant areas of use of salt are the maintenance and de-icing of roads as well as the conditioning of water. In Europe, the possibilities for producing salt by solar evaporation are rather poor and concentrated around the Mediterranean area. Therefore, this dataset represents the production of dry sodium chloride by underground mining (51%) and by solution mining (49%). This dataset is based on data from a European salt producer, as well as literature. 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,. Gendorf (2016) Umwelterklärung 2015, Werk Gendorf Industriepark, www.gendorf.de.
Origin: /Bund/UBA/ProBas
Tags: Natriumchlorid ? Magnesiumchlorid ? Magnesiumsulfat ? Chloralkaliindustrie ? Cerdioxid ? CO2-Emission ? Seen ? Calcium ? Primärbatterie ? Meerwasser ? Salzsäure ? Salzstock ? Steinsalz ? Umweltauswirkung ? Wind ? Salz ? Salzgewinnung ? China ? Main ? Schweiz ? Seltene Erden ? Solartechnik ? Verdunstung ? Kalzinierung ? Metall ? Kaverne ? Kohlendioxid ? Ackerrandstreifen ? Untertagebau ? Australien ? Aufbereitungstechnik ? Erzverhüttung ? Chemikalien ? Regen ? Wasser ? Reinigungsverfahren ? Auflösen ? Aufbereitungsanlage ? Flächenanteil ? Industrielle Ökologie ? Umweltschutz ? Niederschlag ? Chemische Reaktion ? Mining and quarrying ? Other mining and quarrying ? Extraction of salt ? Mining and quarrying n.e.c. ?
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Language: Deutsch
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