Method for the disposal of aqueous sewage sludge
AssigneesOnoda Cement Co., Ltd., Onoda Chemico Co., Ltd.
InventorsIsao Yamane, Toru Saito, Masao Shimoda, Satoshi Kouchi
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Abstract
A combination of a dehydration process for dehydrating sewage sludge by mixing a quicklime-containing material with the sludge, a cement conversion process for introducing the solids produced by the dehydration process into a cement kiln with other cement raw materials to yield cement, and a gas treatment process for introducing gases generated in the dehydration process into a cement burning process, thereby enabling conversion of the sewage sludge into cement without releasing wastes, with a reduction in fuel consumption for the cement burning, and a reduction in NOx content of the exhaust gas.
Claims15
A method for the disposal of aqueous sewage sludge, consisting essentially of water and organic substances, said method comprising;
- dehydration of said sludge by mixing with a quick lime-containing material to form solids and a gas, said gas containing ammonia and water vapor,
- conversion of said solids to cement by heating with additional cement-forming raw materials, there being a maximum of 30 percent of said solids based on the total amount of said cement-forming raw materials,
- separation of said water vapor from said gas, and
- reintroduction of said gas in said heating step.
Dependencies are inferred from the claim text.