Non-ferrous Smelting Industry Research Articles

One Step Interface Activation of ZnS Using Cupric Ions for Mercury Recovery from Nonferrous Smelting Flue Gas.

The flue gases with high concentration of mercury are often encountered in the nonferrous smelting industries and the treatment of mercury-containing wastes. To recover mercury from such flue gases, sorbents with enough large adsorption capacity are required to capture and enrich mercury. ZnS is a cheap and readily prepared material, and even can be obtained from its natural ores. In this work, a simple controllable oxidation method-soaking in cupric solution-was developed to improve the interfacial activity of ZnS and its natural ores for Hg0 adsorption. The gaseous Hg0 adsorption capacity of ZnS was enhanced from 0.3 to 3.6 mg·g-1 after such treatment. Further analysis indicated that a new interface rich in S1- ions was formed and provided sufficient active sites for the chemical adsorption of Hg0. In addition, the cyclic Hg0 adsorption and recovery experiments demonstrated that the adsorption performance of spent activated-ZnS was recovered after reactivating sorbents with Cu2+, indicating the recovery of activated interface. Meanwhile, the high concentration of adsorbed mercury at the surface can be collected using a thermal treatment method. Utilization of raw materials from a zinc production process provides a promising and cost-effective method for removing and recovering mercury from nonferrous smelting flue gas.

Transport and transformation of mercury during wet flue gas cleaning process of nonferrous metal smelting.

Reducing mercury emission is hot topic for international society. The first step for controlling mercury in fuel gas is to investigate mercury distribution and during the flue gas treatment process. The mercury transport and transformation in wet flue gas cleaning process of nonferrous smelting industry was studied in the paper with critical important parameters, such as the solution temperature, Hg0 concentration, SO2 concentration, and Hg2+ concentration at the laboratory scale. The mass ratio of the mercury distribution in the solution, flue gas, sludge, and acid fog from the simulated flue gas containing Hg2+ and Hg0 was 49.12~65.54, 18.34~35.42, 11.89~14.47, and 1.74~3.54%, respectively. The primary mercury species in the flue gas and acid fog were gaseous Hg0 and dissolved Hg2+. The mercury species in the cleaning solution were dissolved Hg2+ and colloidal mercury, which accounted for 56.56 and 7.34% of the total mercury, respectively. Various mercury compounds, including Hg2Cl2, HgS, HgCl2, HgSO4, and HgO, existed in the sludge. These results for mercury distribution and speciation are highly useful in understanding mercury transport and transformation during the wet flue gas cleaning process. This research is conducive for controlling mercury emissions from nonferrous smelting flue gas and by-products.

Energy Efficiency of the Outotec® Ausmelt Process for Primary Copper Smelting

The global, non-ferrous smelting industry has witnessed the continual development and evolution of processing technologies in a bid to reduce operating costs and improve the safety and environmental performance of processing plants. This is particularly true in the copper industry, which has seen a number of bath smelting technologies developed and implemented during the past 30 years. The Outotec® Ausmelt Top Submerged Lance Process is one such example, which has been widely adopted in the modernisation of copper processing facilities in China and Russia. Despite improvements in the energy efficiency of modern copper smelting and converting technologies, additional innovation and development is required to further reduce energy consumption, whilst still complying with stringent environmental regulations. In response to this challenge, the Ausmelt Process has undergone significant change and improvement over the course of its history, in an effort to improve its overall competitiveness, particularly with respect to energy efficiency and operating costs. This paper covers a number of recent advances to the technology and highlights the impacts of these developments in reducing energy consumptions for a range of different copper flowsheets. It also compares the energy efficiency of the Ausmelt Process against the Bottom Blown Smelting process, which has become widely adopted in China over the past 5–10 years.

Understanding aqueous trace metal characteristics from industrial sources in China

Trace metals are a group of toxic pollutants that can cause serious damage to ecosystems and humans. To determine the distribution characteristics of aqueous trace metal contamination and identify critical pollution sources, it is necessary to develop a detailed estimation of trace metal emissions. By considering emission-related factors in each industrial sector, we estimate that the emissions were approximately 2, 61 t, 2,684 t, 301 t and 309 t for mercury, cadmium, chromium, arsenic and lead, respectively, in 2010 in China. These values are much higher than those provided in annual statistical reports. Our research identified critical emissions sources, including Shandong, Henan, Jiangsu and Guangdong Provinces and Raw Chemical, Non-ferrous Smelting, Non-ferrous Mining and Metal Products industries. However, Shandong and Metal Products are ignored in ‘The Twelfth 5-Year Plan for Complete Control of Trace Metal Pollution’. This research generally found that the allowable discharge levels had a significant impact on specific sectors. Total emissions are much lower than the maximum allowable under current Chinese emissions regulations but exceed limits recommended by Integrated Pollution Prevention and Control (European Union). Furthermore, our study found that many regions located along upstream reaches of the Yangtze River, like Sichuan Province, are sources of cross-boundary pollution.

Calculated 1993 emission factors of trace metals for Canadian non-ferrous smelters

Emission factors of As, Cd, Cu, Hg, Mn, Ni, Pb, Sb, Se and Zn from the Canadian primary non-ferrous smelting industry have been calculated from publicly available 1993 emission release data and metal production data. With a few exceptions, the calculated weighted average 1993 emission factors for the Canadian non-ferrous metals industry are between approximately 40% and more than 1500 times lower than published emission factors of As, Cd, Cu, Hg, Mn, Ni, Pb, Sb, Se and Zn used in the literature to estimate global inventories of emissions from the world non-ferrous smelting sector. Where comparisons are possible, these calculated emission factors validate, with two exceptions, the EMEP/CORINAIR values suggested to estimate release inventories from lead and copper ( + nickel) production; however, use of the EMEP/CORINAIR values for zinc production would considerably overestimate the releases from the primary Canadian zinc industry.

A mössbauer study of the behavior of iron cations in iron oxide-containing melts at 1400 °C

A Mossbauer spectroscopy technique has been developed to study the distribution of iron cations in slag melts as a function of distance from a reaction surface. A wide range of slag compositions of interest to the nonferrous smelting industry was reduced and oxidized using mixtures of CO, CO2, and Ar. Mossbauer spectra were collected on quenched slag samples for varying conditions between iron saturation and magnetite saturation, l(10-13) to 4(10-6) atm PO2 at 1400 °C. Slag sections were analyzed with a spatial resolution of approximately 500 /am, and details of the ferric and ferrous distribution at the surface and in subsurface regions were studied. In FexO-SiO2-Al2O3 melts exposed to a reducing gas mixture, there is a gradient in ferric iron concen-tration decreasing toward the surface. In the FexO-Al2O3 melt, the reduction of ferric anions at the surface appears to release O2- ions, which increases the coordination of Fe2+. However, in the presence of silica, which is surface active and acidic, reduction of ferric iron does not lead to an excess of O2- at the surface. Lime has a dramatically different effect. It reverses the ferric gradient so that, even during reduction, the ferric concentration at the surface is enhanced. Ferric oxide is surface active in these melts, and under certain conditions, liquid-phase mass transfer is rapid enough to replenish the surface. The presence of a polymer-forming ion, Fe3+, at the surface results in a scarcity of O2- ions and a reduced coordination of Fe2+. In the presence of both SiO2 and CaO, the behavior of ferric iron during reduction depends, to an extent, on the CaO/SiO2 ratio. The behavior of iron oxide melts during reduction is very complex, and the surface-active nature of SiO2 and ferric oxide has a significant influence on the reaction. A quantitative analysis of the overall reaction would have to take these factors into account.

Smoking, Air Pollution, and the High Rates of Lung Cancer in Shenyang, China

A case-control study involving interviews with 1,249 patients with lung cancer and 1,345 population-based controls was conducted in Shenyang, an industrial city in northeastern China, where mortality rates are high among men and women. Cigarette smoking was found to be the principal cause of lung cancer in this population, accounting for 55% of the lung cancers in males and 37% in females. The attributable risk percentage among females is high compared to elsewhere in China, largely because of a higher prevalence of smoking among women. After adjustment for smoking, there were also significant increases in lung cancer risk associated with several measures of exposure to air pollutants. Risks were twice as high among those who reported smoky outdoor environments, and increased in proportion to years of sleeping on beds heated by coal-burning stoves (kang), and to an overall index of indoor air pollution. Threefold increases in lung cancer risk were found among men who worked in the nonferrous smelting industry, where heavy exposures to inorganic arsenic have been reported. The associations with both smoking and indoor air pollution were stronger for squamous cell and small cell carcinomas than for adenocarcinoma of the lung. Risks due to smoking or air pollution were not greatly altered by adjustment for consumption of fresh vegetables or sources of beta carotene or retinol, prior chronic lung diseases, or education level. The findings suggest that smoking and environmental pollution combine to account for the elevated rates of lung cancer mortality in Shenyang.

Methods of noise control in the foundry, problems and limitations : Ihde, W. In: Proceedings of the Symposium on Occupational Health Hazard Control Technology in the Foundry and Secondary Non-Ferrous Smelting Industries, December 10–12, 1979, Chicago, Illinois, USA. National Institute for Occupational Safety and Health, Cincinnati, Ohio, USA, DHHS (NIOSH) Publication No 81–114, 1981, pp 230–237

Methods of noise control in the foundry, problems and limitations : Ihde, W. In: Proceedings of the Symposium on Occupational Health Hazard Control Technology in the Foundry and Secondary Non-Ferrous Smelting Industries, December 10–12, 1979, Chicago, Illinois, USA. National Institute for Occupational Safety and Health, Cincinnati, Ohio, USA, DHHS (NIOSH) Publication No 81–114, 1981, pp 230–237

Occupational vibration in the foundry : Wasserman, D.E. In: Proceedings of the Symposium on Occupational Health Hazard Control Technology in the Foundry and Secondary Non-Ferrous Smelting Industries, December 10–12, 1979, Chicago, Illinois, USA. National Institute for Occupational Safety and Health, Cincinnati, Ohio, USA, DHHS (NIOSH) Publication No 81–114, 1981, pp 253–259

Occupational vibration in the foundry : Wasserman, D.E. In: Proceedings of the Symposium on Occupational Health Hazard Control Technology in the Foundry and Secondary Non-Ferrous Smelting Industries, December 10–12, 1979, Chicago, Illinois, USA. National Institute for Occupational Safety and Health, Cincinnati, Ohio, USA, DHHS (NIOSH) Publication No 81–114, 1981, pp 253–259

Application of the Lime/Limestone Flue Gas Desulfurization Process to Smelter Gases

In this presentation, adaptation of the lime/limestone process for flue gas desulfurization (FGD) is discussed and how this process can be adapted to applications in the nonferrous smelting industry such as fugitive gases, copper reverberatory furnace gases, lead sintering gases, molybdenum roasting plant tail gases, and other weak SO2 smelter gases. Different methods for particulate removal are also discussed with emphasis on how the particulate removal process can be integrated with the desulfurization process.

Some Novel Aspects of the Pyrometallurgy and Vapometallurgy of Nickel

Two innovations in the extractive metallurgy of nickel are described. One is the introduction of the top blown rotary converter (TBRC) to the nonferrous smelting industry for iron slagging and metal making. The other is the application of the Inco Pressure Carbonyl (IPC) process to a wide variety of metallurgical feed materials for the recovery of pure nickel, cobalt and iron.