China
Africa
Explore chapters and articles related to this topic
New Paradigms for Sustainable Mineral Processing
Published in Sheila Devasahayam, Kim Dowling, Manoj K. Mahapatra, Sustainability in the Mineral and Energy Sectors, 2016
Taconite is a low grade of iron ore which must be processed to extract a high grade concentrate, which results in high volumes of tailings. At one Minnesota iron mine, over 130 million metric tons of taconite tailings were produced, and this quantity is approximately 1/12th of the United States’ annual production of commercial crushed stone for construction applications. Taconite tailings, among others, have high potential for use in industrial applications, such as road construction and repairs (Zanko, 2011).
The many causes of mesothelioma
Published in Dorsett D. Smith, The Health Effects of Asbestos, 2015
Allen and coworkers evaluated a cohort of 31,067 taconite workers with at least 1 year of documented employment. Among those, there were 9094 deaths, of which 949 were from lung cancer, and 30 from mesothelioma. Mortality from lung cancer and mesothelioma was higher than expected, with standard mortality ratios (SMRs) of 1.16 for lung cancer (95% confidence interval [CI]: 1.09–1.23) and 2.77 for mesothelioma (95% CI: 1.87–3.96). There is evidence that taconite workers may be at increased risk for mortality from lung cancer, mesothelioma, and some cardiovascular diseases. Occupational exposures during taconite mining operations may be associated with these increased risks, but nonoccupational exposures may also be important contributors. (Allen EM, Alexander BH, Maclehose RF et al. Mortality experience among Minnesota taconite mining industry workers. Occup Environ Med 2014;71(11):744–9.)
Variability of aerosol mass and number concentrations during taconite mining operations
Published in Journal of Occupational and Environmental Hygiene, 2020
Nima Afshar-Mohajer, Rebecca Foos, John Volckens, Gurumurthy Ramachandran
Since late 1950s, the taconite mining industry in Minnesota has been the largest supplier of iron ore to the US steel industry. The dust generated during various processes in taconite mining is a well-recognized health hazard for taconite industry workers as it contains crystalline silica (Sheehy and McJilton 1987). In addition to cardiovascular and respiratory health issues resulting from occupational exposure to high concentrations of respirable particulate matter, crystalline silica found in taconite dust has been associated with silicosis and other fibrotic diseases (Nelson and Murray 2013). The Occupational Safety and Health Administration (OSHA) is currently in the midst of new proposed rule for controlling silica where workers’ exposures would be limited to a new PEL of 50 micrograms of respirable crystalline silica per cubic meter of air (µg/m3), averaged over an 8-hr day (Hwang et al. 2017).
Iron Ore Pelletization: Part I. Fundamentals
Published in Mineral Processing and Extractive Metallurgy Review, 2022
Pelletizing is the most important agglomeration process used in the concentration of iron ore today, representing most iron ore concentrates processed around the world. Whether it be for producing blast furnace feed or direct reduction feed, pelletization is trusted to create a high-quality, structurally-sound, and metallurgically-sound product (Mourão 2008). The availability of high-grade iron ore is only going to continue to decrease and the fraction of lower grade taconites and itabirites being processed will need to increase to maintain iron production.
A Review on Floc-Flotation of Fine Particles: Technological Aspects, Mechanisms, and Future Perspectives
Published in Mineral Processing and Extractive Metallurgy Review, 2023
Kaveh Asgari, Hamid Khoshdast, Fardis Nakhaei, Mohammad Reza Garmsiri, Qingqing Huang, Ahmad Hassanzadeh
Due to the involved limitations and gaps such as lack of knowledge in involved mechanisms, the interaction of flotation and flocculation chemicals and reagents on each other, economic studies, etc. there are limited floc-flotation industrial projects in the world. One of the less-known industrial cases in this regard is the Mesabi Iron Range plant located on Minnesota’s Mesabi Iron Range. This taconite processing plant is using a combination of flocculation and flotation techniques for taconite beneficiation. The plant beneficiates low-grade ores by removing nonferrous rock (gangue) and produces marketable concentrations of iron-bearing material from low-grade ore. Taconite is a hard and low-grade ore. This ore is the main iron ore remaining in the US and about 95% of the crude iron ore in the United States is produced via taconite. Taconite can be involved with two iron minerals of magnetite and hematite. The former rock is called magnetic taconite and the latter is called hematic taconite. The main demand for taconite is from the iron and steel industry. Processing of taconite in this plant is consisting of the liberation of iron-bearing particles via crushing and grinding, beneficiation of the ore by separation of valuable particles from gangue, and pelletizing the iron ore concentrate. As the iron ore minerals are liberated by the crushing steps, the iron-bearing particles must be separated. Magnetic separation and flotation are the most common techniques for beneficiating this ore. Magnetic taconite ore is beneficiated through magnetic separation, while non-magnetic taconite ores are concentrated by froth flotation or by a combination of selective flocculation and flotation. The method is determined by the differences in surface activity between the iron and gangue particles, however, the sharp separation is often difficult (Colombo and Jacobs 1976; Colombo, Hopstock, and Jacobs 1978; Jiang, Wu, and Biewen 1998).