Electric arc furnace dust as raw material for brick
OwnerScott W. Frameinventor
Life of this patent
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Abstract
A process for producing brick involves calcining electric arc furnace dust and subsequently mixing the dust with a brick raw material prior to shaping the material into bricks and firing. The precalcination of the EAF dust greatly increases the bulk density of the dust and provides a brick having a much higher compressive strength when compared to bricks incorporating raw dust which has not been precalcined. Volatilized and recondensed heavy metals produced during the calcination process are collected and refined. As a result of the separation and collection of the volatilized heavy metals during the calcination process, substantially no heavy metals are volatilized during the brick firing process.
Claims24
A method for producing bricks containing electric arc furnace dust produced in an electric arc furnace employed to melt scrap in a steel making process, said method comprising the steps of:
- calcining electric arc furnace dust by heating said dust to a temperature of about 1040.degree. C. or higher to increase the bulk density of the dust and form calcined electric arc furnace dust;
- mixing said calcined dust with a brick raw material comprising clay, shale or mixtures thereof to form a mixture comprising said calcined dust present in an amount of up to about 60 percent by weight;
- forming said mixture into bricks and firing the formed bricks at a temperature of between about 900.degree. and about 1370.degree. C.
A brick comprising 40 to 80 percent by weight of a brick raw material selected from the group consisting of clay, shale and mixtures thereof and 20 to 60 percent by weight of an electric arc furnace dust, wherein said dust has been precalcined at a temperature of about 1040.degree. C. or higher and has a bulk density of at least about 129.3 pounds per cubic foot.
Dependencies are inferred from the claim text.