Problems & Solutions of Cement Industries

Problems (Impacts of Cement Industries) 

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The cement industry is one of two largest producers of carbon dioxide (CO 2), creating up to 5% of worldwide man-made emissions of this gas, of which 50% is from the chemical process and 40% from burning fuel. Cement manufacture contributes greenhouse gases both directly through the production of carbon dioxide when calcium when  calcium carbonate is thermally decomposed and particularly from the combustion of  fossil  fossil fuels. They fuels. They are also responsible for nitrogen oxides, sulphur oxides and Dioxin emissions. Concrete is used to create hard surfaces which contribute to surface runoff that may cause soil cause soil erosion, water erosion, water pollution and flooding. Concrete dust released by building demolition and natural disasters can be a major source of dangerous air pollution. This dust is of a mineral nature with similar constituents to cement  – silica, alumina, iron and calcium compounds. The presence of t hese substances in concrete, including useful and unwanted additives, can cause health concerns due to toxicity and radioactivity. Dust emissions originate mainly from the raw mills and the cement mills. They have been linked to respiratory problems such as Tuberculosis. Foul smell is sometimes a direct result of the gases emitted during cement manufacturing. Moreover, since cement manufacture has life threatening impacts to plants and animals, the manufacturing process then directly and indirectly gives rise to offensive smells as the dead plants and animals decay.

fibre)  cement sheet", more commonly called "asbestos cement Fibro is short for "fibrous (or fibre) cement sheet" or "AC sheet". It is a building material in which asbestos fibres are used to reinforce thin rigid cement sheets. The use of fibro has now been banned been  banned in several countries, due countries,  due to its asbestos content. Asbestos is directly related to a number of life-threatening diseases including, asbestosis, including, asbestosis, pleural  pleural mesothelioma (lung) and peritoneal and peritoneal mesothelioma (abdomen). Fibre (abdomen). Fibre cement sheet is still readily available, but the reinforcing fibres are now cellulose rather than asbestos.

Cement and its products also causes c auses health hazards through skin contact, eye contact and inhalation. Due to its highly alkaline nature (pH 13), it can penetrate the  skin and cause burns and o ulcers. It can cause eye irritation, redness or even blindness when exposed to eyes. o Inhalation of cement dust causes irritation of nose and throat, and if prolonged, may o lead to fatal lung diseases like silicosis.

Solutions

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An Italian company ‘Italcementi’ designed a kind of cement that is supposed to fight air pollution by breaking down pollutants that come in contact with the concrete, thanks to the use of  Titanium dioxide absorbing UV light. Another proposed method of absorbing emissions is to absorb CO 2 in the curing process. Recent research has proposed that the use of an admixture (Dicalcium Silicate γ phase) that absorbs CO2 as the concrete cures. With the use of coal ash or another suitable substitute, this concrete could theoretically have a CO2 emissions below 0 kg/m 3, compared to normal concrete at 400 kg/m 3.

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Surface runoff , when water runs off  impervious surfaces, such as non-porous concrete, can

cause severe soil erosion and flooding. Urban runoff tends to pick up gasoline, motor oil, heavy metals, trash and other pollutants from sidewalks, roadways and parking lots. In an attempt to counteract the negative effects of impervious concrete, many new paving projects have begun to use pervious concrete, which provides a level of automatic storm water management. It allows for surface runoff to seep through and return to the groundwater. This both prevents flooding and contributes to groundwater replenishment.

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Concrete recycling is an increasingly common method of disposing of concrete structures.

Concrete debris was once routinely shipped to  landfills for disposal, but recycling is increasing due to improved environmental awareness, governmental laws and economic benefits.

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The control of fugitive dust is done by: Ventilation systems should be used in conjunction with hoods and enclosures covering o transfer points and conveyors; o Drop distances should be minimized by the use of adjustable conveyors; o Dusty areas such as roads should be wetted down to reduce dust generation; Appropriate storm water and runoff control systems  should be provided to minimize o the quantities of suspended material carried off site. o Mechanical systems for controlling dust using applications of Dust collectors, Cyclones, Electrostatic Precipitator.