From the available statistical data, cement factories co-process a range of over 100 types of waste (sorted both industrial and household) being authorized for their use as combustion components in clinker ovens. Therefore, the level of emissions is different depending on the type of fuels and waste used. The amount of industrial and municipal co-processed waste in the Romanian cement industry from 2004 to 2013 was about 1,500,000 tons, the equivalent of municipal waste generated in a year for 18 cities with over 250,000 inhabitants. The objective of this paper was to evaluate the emission level of hydrochloric acid (HCl) and hydrofluoric acid (HF) at the clinker kilns at two cement factories in Romania for different annual time intervals and to do a comparative analysis, to estimate their compliance with legislation in force. The measurements results showed average emission levels of about 0.578 mg/Nm3 for HCl and about 0.100 mg/Nm3 for HF, in the first hours of the evening, but decreased at the beginning of the third tour, at about 0.385 mg/Nm3 for HCl, respectively, to about 0.085 mg/Nm3 for HF. The evolution of HCl and HF emission levels during the last 4 years showed a variable distribution of these acids.
This paper presents aspects of monitoring material dust emissions from stationary emission sources (monthly dust measurements performed on cement mill stacks—mill outlet and separator outlet). Additionally, the Portland cement mill technological process (its component parts), as well as the solutions regarding the reduction of the air emissions level, following the emission limit values (VLE), established in the integrated environmental authorization (AIM) from a cement factory in Romania, were analyzed. The paper focused on analyzing the data obtained in three different years for PM10 and dust concentrations (2018–2020). For each year, the measurements have been done in 3 months, each in a different season. The average values for each year for working conditions were: 30.22 mg/m3 (2018), 27.38 mg/m3 (2019), and 27.51 mg/m3 (2020) for working conditions and for normal conditions: 34.22 mg/m3 (2018), 30.49 mg/m3 (2019), and 30.16 mg/m3 (2020). For all 3 years, the values measured in spring were higher than the other two, both for work and normal conditions.
Worldwide, in the rotary kilns of cement plants, various amounts of combustible waste are burned, which would otherwise end up in municipal landfills. The paper first analyzes the literature on the co-processing of waste in cement manufacture and its influence on the environment and human health. Then, it shows how the combustion components of co-processed waste can influence the final characteristics of clinker and cement. The main objective of the paper is to determine the level of emissions of the resulting pollutants (total dust and flue gases: NOx, SO2, and CO) at the outlet of the chimney of the clinker kiln and flour mill to meet the requirements of the Integrated Environmental Permit (EIA) from Romania and present an estimation of the level of atmospheric air pollution using the climatological model of pollutant dispersion. Following these assessments (data shown), the cement factories will establish measures to reduce the pollution, if necessary, to comply with the regulations in force for the cement industry.
This paper presents results regarding the grinding behaviour of two batches of material (clinker) in a ball mill with its own two-step grinding process: the first one with a ball load, the second with a load of cylindrical metal bodies. The first step was performed until the residue R009 has reached aprox.35%, and the second stage until Blaine's specific surface was over 3800 cm2/g. Periodically, at 10-minute intervals, the fineness of the clinker and the specific energy consumption were determined. These consumptions are quantified from the first determination and relates to the weight of the material subjected to grinding (20 kg clinker / from a source), determining the grinding ability of the material.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.