Resource StreamResource Stream

Clay BrickClay Brick

By Bob FromtlingBy Bob Fromtling

Resource AcquisitionResource Acquisition Materials Required: Materials Required:

clay, sand, fuel clay, sand, fuel (varies), and (varies), and manpower.manpower.

Clay is Clay is extracted/mined extracted/mined from clay quarriesfrom clay quarries

Soil must contain Soil must contain from 25 to 50% clay from 25 to 50% clay and siltand silt

Copyright 1997 Haruhiko Suga

Environmental Impacts of Environmental Impacts of ExtractionExtraction

New extraction sites can have adverse New extraction sites can have adverse impacts on local landscape, habitats, impacts on local landscape, habitats, animals, and plantsanimals, and plants

Quarrying process produces silt laden Quarrying process produces silt laden waters that can escape through storm waters that can escape through storm runoff to contaminate surrounding surface runoff to contaminate surrounding surface and ground watersand ground waters

Clay particles also enter the air surrounding Clay particles also enter the air surrounding a quarrya quarry

Many extraction sites are used as landfills Many extraction sites are used as landfills after the clay has all been extracted, which after the clay has all been extracted, which has significant environmental impactshas significant environmental impacts

Brick ProductionBrick Production

The clay soils are mixed with water for The clay soils are mixed with water for plasticity and sand to keep them from plasticity and sand to keep them from sticking to the brick moldssticking to the brick molds

The material is then extruded through a The material is then extruded through a large opening making a sheet that can be large opening making a sheet that can be cut into brickscut into bricks

Through new Stiff Extrusion technology, Through new Stiff Extrusion technology, the bricks contain much less moisture, the bricks contain much less moisture, shortening the drying and heating shortening the drying and heating processes and reducing the wastage of processes and reducing the wastage of bricks through handlingbricks through handling

Production ContinuedProduction Continued After being cut, bricks After being cut, bricks

are stacked and dried, are stacked and dried, either by open air or by either by open air or by the excess heat from the the excess heat from the brick kilnsbrick kilns

Once they have dried Once they have dried sufficiently to remove sufficiently to remove moisture, the bricks are moisture, the bricks are heat treatedheat treated

It is through this heating It is through this heating that the alkalis in the clay that the alkalis in the clay and the oxides from iron and the oxides from iron and other metals join and other metals join with the alumina and with the alumina and silica in the clay to give silica in the clay to give the bricks their desired the bricks their desired hardnesshardness

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Production: KilnsProduction: Kilns A kiln is an oven or furnace where bricks are fired A kiln is an oven or furnace where bricks are fired

or heat treated to develop their hardnessor heat treated to develop their hardness Brick production is a very energy intensive Brick production is a very energy intensive

process and large amounts of fuel must be process and large amounts of fuel must be burned to acquire the correct hardness in the burned to acquire the correct hardness in the bricksbricks

Openings are left in the kiln to release the Openings are left in the kiln to release the combustion gases and pieces of metal can be slid combustion gases and pieces of metal can be slid on and off of these openings to control the rate at on and off of these openings to control the rate at which the fire burnswhich the fire burns

Depending on the technology being used the Depending on the technology being used the fuels for a kiln vary from wood and charcoal fuels for a kiln vary from wood and charcoal (most commonly) to natural gases or even waste (most commonly) to natural gases or even waste materials, such as sawdust, pecan shells, plastic materials, such as sawdust, pecan shells, plastic wastes, agricultural wastes, and scrap tireswastes, agricultural wastes, and scrap tires

Kilns ContinuedKilns Continued Depending on fuels Depending on fuels

used, the heating used, the heating process can go on process can go on from anywhere from anywhere between 17 hours and between 17 hours and 8 days and the prime 8 days and the prime heat level is about heat level is about 885° Celsius885° Celsius

If the fuel runs out and If the fuel runs out and the temperature falls the temperature falls under the correct under the correct level, the entire load level, the entire load of bricks could be lostof bricks could be lost

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Environmental Impacts of Environmental Impacts of ProductionProduction

The dangerous pollutants emitted by The dangerous pollutants emitted by brick kilns are numerous and variedbrick kilns are numerous and varied

These emissions are produced from These emissions are produced from the burning of the fuels as well as the burning of the fuels as well as from the bricks themselves as they from the bricks themselves as they are heatedare heated

These emissions can be extremely These emissions can be extremely unhealthy to kiln workers as well as unhealthy to kiln workers as well as the surrounding flora, fauna, and the surrounding flora, fauna, and residentsresidents

Environmental Impacts: Air Environmental Impacts: Air PollutantsPollutants

Nitrogen oxides are produced by the Nitrogen oxides are produced by the burning of hydrocarbon fuels and cause burning of hydrocarbon fuels and cause acid rain as well as local air pollutionacid rain as well as local air pollution

Sulfur dioxides are produced by the Sulfur dioxides are produced by the heating of the clay and the burning of heating of the clay and the burning of any oils or coals as a fuel sourceany oils or coals as a fuel source

Carbon monoxide and carbon dioxide Carbon monoxide and carbon dioxide are produced when hydrocarbon fuels are produced when hydrocarbon fuels are burned and CO causes local air are burned and CO causes local air pollution while CO2 causes global pollution while CO2 causes global warmingwarming

Air Pollutants ContinuedAir Pollutants Continued Other organic compounds, even toxins Other organic compounds, even toxins

such as dioxin can be released if waste such as dioxin can be released if waste compounds are used to fuel a kilncompounds are used to fuel a kiln

Particulate matter is produced by the Particulate matter is produced by the firing of the bricks themselves and from firing of the bricks themselves and from the burning of heavy fuel oil, coal, and the burning of heavy fuel oil, coal, and waste materialswaste materials

Many of these problems could be Many of these problems could be greatly remedied and reduced by the greatly remedied and reduced by the use of better technology, which reduces use of better technology, which reduces waste and increases efficiencywaste and increases efficiency

DisposalDisposal

The only options in brick disposal are The only options in brick disposal are landfills or recyclinglandfills or recycling

Bricks are often moved to landfills where Bricks are often moved to landfills where they serve no purpose other than to take up they serve no purpose other than to take up spacespace

Bricks can be recycled in a variety of ways Bricks can be recycled in a variety of ways ranging from being reused as whole bricks in ranging from being reused as whole bricks in future construction projects to being crushed future construction projects to being crushed and graded for use in road construction, and graded for use in road construction, driveways, or as sand or river graveldriveways, or as sand or river gravel

Environmental Impacts of Environmental Impacts of DisposalDisposal

The only problem with the disposal of The only problem with the disposal of bricks is when they are put into bricks is when they are put into landfillslandfills

Recycling is an excellent cost Recycling is an excellent cost efficient way to reduce the amount of efficient way to reduce the amount of brick material that ends up in brick material that ends up in landfillslandfills

Ways to Increase Energy Ways to Increase Energy Efficiency and Reduce Waste Efficiency and Reduce Waste

Brick kilns use a large amount of Brick kilns use a large amount of energy and emit a large amount of energy and emit a large amount of pollutantspollutants

By using new and inexpensive By using new and inexpensive technology both of these factors can technology both of these factors can be significantly improvedbe significantly improved

In India the brick industry is huge In India the brick industry is huge and steps are being taken to improve and steps are being taken to improve their emissions and energy usetheir emissions and energy use

Vertical Shaft Brick KilnsVertical Shaft Brick Kilns VSBK save between 30 and 50% more VSBK save between 30 and 50% more

energy than traditional brick kilnsenergy than traditional brick kilns Because of its roof VSKB can operate in Because of its roof VSKB can operate in

all weather conditions year round all weather conditions year round instead of only 6 months per yearinstead of only 6 months per year

Because of energy efficiency and Because of energy efficiency and improved combustion air flow efficiency improved combustion air flow efficiency the amount of suspended particulate the amount of suspended particulate matter in the emitted flue gases and matter in the emitted flue gases and other pollutants are greatly reducedother pollutants are greatly reduced

Vertical Shaft Brick Kiln: Vertical Shaft Brick Kiln: Statistics and PictureStatistics and Picture

Property of Teri Organization

Other Simple Means of Other Simple Means of Increasing Environmental Increasing Environmental

PerformancePerformance By drying the bricks for extended periods of time By drying the bricks for extended periods of time

fuel requirements are reducedfuel requirements are reduced By preheating kilns with cleaner burning propane By preheating kilns with cleaner burning propane

or natural gas before switching to waste fuels or natural gas before switching to waste fuels such as sawdust, production speed and quality such as sawdust, production speed and quality can be increasedcan be increased

By simply raising the bricks on a metal grill above By simply raising the bricks on a metal grill above the fuel, air flow and combustion increase, the fuel, air flow and combustion increase, reducing particulate matter and other emissionsreducing particulate matter and other emissions

By reducing air leaks and controlling the size of By reducing air leaks and controlling the size of the kiln opening, combustion can be improved, the kiln opening, combustion can be improved, hence leaving less partially burned fuelshence leaving less partially burned fuels

Environmental Benefits of Brick Environmental Benefits of Brick ProductionProduction

Fly-ash is a byproduct of the burning of soft coals Fly-ash is a byproduct of the burning of soft coals such as Bituminous coals. It consists of the lighter such as Bituminous coals. It consists of the lighter particles of ash that fly into the air, hence the nameparticles of ash that fly into the air, hence the name

Fly-ash is a known carcinogen and can cause skin Fly-ash is a known carcinogen and can cause skin and lung diseases. It also reflects infra-red rays, and lung diseases. It also reflects infra-red rays, contributing to global warming. It is being produced contributing to global warming. It is being produced in huge quantities in such countries as India and in huge quantities in such countries as India and Australia, who both have large brick industriesAustralia, who both have large brick industries

If stiff extrusion technology is used, maximum If stiff extrusion technology is used, maximum amounts of non-plastic (clay) material can be usedamounts of non-plastic (clay) material can be used

With this technology 30-60% of fly-ash can be used With this technology 30-60% of fly-ash can be used in the production of bricks. This is a wonderful way in the production of bricks. This is a wonderful way to recycle a substance that has no other use, is very to recycle a substance that has no other use, is very hard to dispose of, and has terrible environmental hard to dispose of, and has terrible environmental and health effectsand health effects

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