The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 23, 2010
Filed:
Oct. 19, 2007
Junichi Terasaki, Kumagaya, JP;
Hajime Wada, Kumagaya, JP;
Takahiro Hayashida, Sakura, JP;
Soichiro Okamura, Kumagaya, JP;
Junichi Terasaki, Kumagaya, JP;
Hajime Wada, Kumagaya, JP;
Takahiro Hayashida, Sakura, JP;
Soichiro Okamura, Kumagaya, JP;
Taiheiyo Cement Corporation, Tokyo, JP;
Abstract
A method to efficiently reduce lead content of cement without exerting influence upon quality of the cement. The method comprises the steps of: controlling O2 concentration of combustion gas in an inlet end of a cement kiln to 5% or lower and/or CO concentration thereof 1000 ppm or more; extracting a part of combustion gas from the cement kiln and collecting dust contained in the combustion gas; and collecting lead from the dust collected. With this, the area where raw material temperature in the cement kiln is between 800° and 1100° can be turned into reducing atmosphere to sharply increase volatilization rate of lead, and collection of lead from the dust allows lead content of cement to efficiently be reduced without exerting influence upon quality of the cement.