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Metal–Crucible Interactions
Published in Nagaiyar Krishnamurthy, Metal–Crucible Interactions, 2023
The word smelting is probably the most used term in any extractive metallurgy text. It represents the process by which a metal is obtained in the elemental form, or even as a simple compound, from its ore. Smelting involves heating beyond the melting point, usually in the presence of oxidizing agents, such as air, or reducing agents, such as coke. As noted earlier, copper was the first metal to be smelted in ancient times, followed by tin, lead and silver.
Metals
Published in Ronald M. Scott, in the WORKPLACE, 2020
Arsenic is used as an alloying agent with lead in type, battery plates, bearings, cable sheathing, and shot for ammunition. It is obtained as a by-product of the processing of other ores. Arsenic trioxide is driven off during the smelting of gold, lead, or especially copper ores, and can be harvested in cooling chambers. The risk of exposure is serious in the smelting operation. The harvesting and transporting of the oxide must be done cautiously, as must repair work to furnaces, cleaning of flues, or other maintenance operations.
Converting Minerals to Metals
Published in Karlheinz Spitz, John Trudinger, Mining and the Environment, 2019
Karlheinz Spitz, John Trudinger
The second main solid waste streams listed above originate from air pollution controls (e.g. gypsum from scrubbers) and water treatment facilities. These wastes are usually sludges and may be hazardous. Final disposal is difficult and generally costly. Modern smelting technologies aim to reduce gaseous emissions and solid wastes. Wastes destined for disposal from metal production are kept to a minimum (Figure 7.5). Flue dusts are typically recycled to the smelting furnaces. Dust from the bag filters and metals precipitated in the wastewater treatment plant are also fed to flash smelting furnaces as secondary materials. Fine examples of internal waste material management are the Outotec Smelting and the Mitsubishi Continuous Smelting technologies that practically eliminate the production of hazardous solid waste in copper production (Case 7.5).
Preparation of MgX/Al2O3-Y sorbent for highly efficient simultaneous removal of hydrogen fluoride and hydrogen chloride under low-temperature environment
Published in Environmental Technology, 2023
Jiayu Feng, Kai Li, Ping Ning, Chi Wang, Xin Sun, Fei Wang, Peng Gao
Nowadays, harmful gas emissions have become a major challenge for the efficient and sustainable development of the smelting industries. Despite attempts to research smelting off-gas purification technologies around the world, it is difficult to achieve cost-effective exhaust gas purification due to cost constraints. Hydrogen fluoride (HF) and hydrogen chloride (HCl) often exist in the copper smelter off-gas [1, 2]. Due to the high toxicity and volatility of HF and HCl, they are often regarded as highly hazardous pollutants and have been paying increasing attention recently [3, 4]. The release of HF and HCl into the atmosphere will cause a powerful greenhouse effect [5], environmental pollution, and human health problem [6, 7]. However, in the past three decades, the emission of HF and HCl has not been given enough attention in some areas. Recently, with the increase in the stricter atmospheric emission standards, HF and HCl have drawn increasing attention from scholars worldwide. In many countries, emissions of HF and HCl are severely restricted by law.
Identifying and prioritizing export-related CSFs of steel products using hybrid multi-criteria methods
Published in Cogent Engineering, 2022
Nazli Monajemzadeh, Amir Karbassi Yazdi, Thomas Hanne, Shayan Shirbabadi, Zahra Khosravi
With the growth in foreign trade, earnings and increasing domestic demand, especially for steel products, the volume of investing in steel production projects rises dramatically. Growth and limitations in production affect the prices of crude steel products. These effects are intensified by the fact that the smelting industry is considered time-consuming, risky, and costly. Hence, the market requires essential government support to grow in line with demand, but surplus to requirements may be achieved through imports (J. Chen et al., 2018). In order to understand the effects of financial factors on changes in the costs of nonferrous materials, a theoretical framework was designed by J. Chen et al. (2018). Also, for analyzing nonlinear relationships, a Markov-Switching Vector Auto-Regression (MS-VAR) model is used based on price data from August 2004 to October 2016 of international copper futures (Mehmanpazir et al., 2019).