There are 30~40 dust emission points and discharge points in the cement production line from material mining to finished product packaging. Generally speaking, for every ton of cement produced, 2.8~3.0 tons of materials have to be processed and 13000~15000m³ (standard state) of flue gas is generated.
Main dust removal points in the cement industry: coal powder mill dust removal, dryer dust removal, firing dust removal (kiln head grate cooler dust removal, kiln tail dust removal), cement mill dust removal, slag fine powder powder station dust collection, material storage and packaging dust collection wait. Overall, it is divided into three parts: raw material preparation dust removal, burning dust removal and product preparation and packaging dust removal.
1. Dust and main exhaust gas pollutants in the cement industry
① CaCO3 (calcium carbonate) dust that is not completely decomposed in the calciner of cement raw meal;
② CaO (calcium oxide) dust produced during the decomposition of CaCO3;
③ SO2 (sulfur dioxide), NOx (nitrogen oxides), CO (carbon monoxide), CO2 (carbon dioxide) and other gases produced during the combustion of pulverized coal for calcination;
④ The temperature of the kiln exhaust gas coming out of the cyclone is above 320°C, and the gas is dry;
⑤ The dust concentration is above 85mg/Nm3 (mg/standard cubic meter), and the dust particle size is less than 10 (μm) microns, accounting for more than 90%;
⑥ The NOX content is about 250PPm (one part per million);
⑦ The content of SO2 generally changes with the sulfur content of coal, and it is basically absorbed by CaO and remains in the clinker;
⑧ CO, CO2 content sometimes fluctuates according to the combustion sufficiency of pulverized coal
The main dust removal points in the cement industry are divided into three categories:
1. Raw material preparation and dedusting (raw material): Coal mill, dryer dedusting
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2. Firing dust removal (cement kiln tail, kiln head grate cooler)
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3. Product preparation and packaging dust removal (clinker): cement mill dust removal, grinding station dust collection, material storage and packaging dust removal
Material selection: polyester needle felt
