Environmental Health and Safety Aspects in the Cement Industry Antonio Jose Cumbane (PhD) Maputo, 31 st May 2011
Content The Mozambique Cement Industry Cement manufacturing Environmental Health and Safety Characterization Production process Waste characterisation Possible pollution prevention and control measures Conclusions
In 1973 the Matola factory increased production to 262,200 tons/year The Mozambique Cement Industry The first reported cement production started in 1920 at Matola Plant; Based on a wet processing; Installed production capacity of 45,000 tons/year;
25 0'0"S 25 0'0"S 20 0'0"S 20 0'0"S 15 0'0"S 15 0'0"S Cont. TANZANIA ZAMBIA DR CONGO ZIMBABWE BOTSWANA SOUTH AFRICA 30 0'0"E 35 0'0"E 40 0'0"E # SWAZILAND Matola MALAWI MOZAMBIQUE # Beira I N D I A N O C E A N 30 0'0"E 35 0'0"E 40 0'0"E # Nacala 0 125 250 375 500 kms CIMPOR GROUP owns all the 3 processing plants: Matola, Dondo and Nacala; Location chosen on the basis availability of raw materials: limestone, clay
Cont. In 1973 change in machinery to allows cement production by dry process; Later production capacity was increased to 240,000 tons/yr of clinker and 400,000 tons/yr of cement; Coal was used as the main source of energy; In 2009 a project was drafted to change the fuel from coal to natural gas;
WHAT ISSUES IS THE SECTOR FACED WITH? Environmental Pollution Increased demand of portland cement for construction
ENVIRONMENTAL POLLUTION Environmental Pollution Increased demand of portland cement for construction
ENVIRONMETAL POLLUTION The surrounding industrial companies claim that dust stemming from the cement facility accumulates in huge quantities in their sites, forcing them to make constant cleansing and shortening the life expectancy of their equipment and refrigeration appliances; Neighbouring households claim that dust contribute to prevalence of respirable diseases.
Environmental Pollution
Human respiratory system Airborne silica dust enters the body primarily by inhalation The inhaled airborne dust particles smaller than 10 µm can be deposit in the area of respiratory bronchioles This lead to the development of pneumoconiosis with increased risk of
Industries related with silica dust pollution SOME STATISTICS OF SILICOSIS DIAGNOSED BY NIOH FROM 1991-2004 INDUSTRY NUMBER (%) FOUNDRY 103 55 POTTERY 24 13 REFRACTORY 22 12 ENGINEERING 12 6 QUARRYING 9 5 CONSTRUCTION 8 4 CHEMICAL 4 2 STONE MASONRY 3 2
CEMENT MANUFACTURING EHS CHARACTERISATION Production process: Raw material and coal preparation Clinker baking Clinker cooling and cement milling Packaging, storage and delivery Waste characterisation Possible pollution prevention and control measures
Production process
Raw materials quarrying Main hazardous factors Dust: emitted to working environment Noise: emitted during balsting, crushing and operation of conveyors
Raw materials preparation Dust: emitted during discharge of raw material in the warehouses, operation of crushers an grinders Toxic gas: during pre-heating to reduce humidity, emission of CO, C)2, NOx and SO2 Noise: emitted from crushers, millers Heat pollution in the areas nearby dry kiln of limestone and coal due to use of recycled heat of kiln
Clinker baking Workers are exposed to dust, toxic gases, high heat radiation and high workload
Clinker cooling and cement milling Auxiliary materials such as gypsum, and additives are added into clinker The mixture undergo an homogenisation and milling Main pollutant and hazards: Dust Heat emitted from hot clinker on belt conveyor Noise emitted from clinker crushers and cement millers
Packing, storage and delivery Main dust hazardous: Dust Packing is the most polluting process in the cement production Use of semi-automated packing machines Use of open conveyors without exhausting system High workload: Workers carry 45-50 kg bags in dusty, hot and bad lighting environment Worker have high risks of muscle-skeletal diseases as low back pain, spinal column, shoulders pain
Hot air Hot air Lime stone-clay-additives Crushing Dust, Noise Storage Energy Raw milling Dust, Noise Preheating Flue gas (CO, NO x, SO 2, dust ) Energy Pre-calcining Rotary kiln Cooling Dust Clinker Crushing Dust, Noise Clinker Storage Gypsum Additives Crushing Cement milling Dust, Noise Energy Cement Storage Bulk load Packaging Storage Packaging waste-dust Impacts of the Cement Process
WASTE CHARACTERISATION Cement kiln dust (CKD) comprise: Clinker cooler Crushers Grinders Materials handling Major source of emissions such as: Carbon dioxide (CO2), 2.4% global warming emissions Sulfur dioxide, source of acid rains Nitrogen oxides (Nox) Volatile organic compounds (VOC)
CONCLUSIONS CEMENT MANUFACTURING IS ASSOCIATED WITH NEGATIVE IMPACTS: Dust emissions in the combustion gases Emission of noise located Generation of solid waste Occupational health an safety of workers and local communities
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