Method for controlling free lime content of clinker

Patent metadata

Field	Value
Publication number	US-9598312-B2
Application number	US-201314388513-A
Country	US
Kind code	B2
Filing date	Mar 8, 2013
Priority date	Mar 29, 2012
Publication date	Mar 21, 2017
Grant date	Mar 21, 2017

Abstract

Provided is a method for controlling a free lime content of a clinker by regulating the free lime content. Here the amount of sulfur trioxide resulting from fuel and the used amount of a fluorine-based mineralizer are regulated using the following Formulas (1) to (3), thereby controlling the free lime content (f.CaO) of the clinker.

f.CaO=0.29×e (0.65×A) ( A=a ×SO 3 +b )  (1)

a=0.0001×F+9.2×t−0.18×HM−9.2   (2)

b=−0.0005×F−32.8×t−2.9×HM+28.4   (3)

SO 3 is an amount of sulfur trioxide in the clinker; a is a coefficient satisfying Formula (2); b is a coefficient satisfying Formula (3); F is an amount of fluorine in the clinker; when a burning temperature is X° C., t=X/1450; and HM is a hydraulic modulus.

First claim

The invention claimed is:

1. A method for controlling a free lime content of a cement clinker, comprising:
adding fluorite or fluorine-containing waste that is a fluorine source in the cement clinker and used as a mineralizer to raw materials of the cement clinker,
intermixing a waste gypsum board powder with fuel or putting the waste gypsum board powder into a kiln from the kiln outlet part as an SO 3 source in the cement clinker,
burning the raw materials of the cement clinker added the fluorite or the fluorine-containing waste in the kiln to produce the cement clinker,
calculating the free lime content (f.CaO) of the cement clinker according to Formulas (1) to (3),
adjusting an additive amount of fluorite or fluorine-containing waste and an used amount of fuel or an additive amount of waste gypsum according to the calculated free lime content to control the free lime content (f.CaO) so as to fall within a range of 0.5<f.CaO<1.0,
f.CaO=0.29 ×e (0.65×A) ( A=a ×SO 3 +b )  (1)

a =0.0001 ×F +9.2 ×t −0.18 ×HM −9.2  (2)

b =−0.0005 ×F −32.8 ×t +2.9 HM +28.4  (3)

in Formula (1), f.CaO is a free lime content (wt %),
SO 3 is an amount (wt %) of sulfur trioxide in the cement clinker,
a is a coefficient satisfying Formula (2),
b is a coefficient satisfying Formula (3),
F is an amount (mg/kg) of fluorine in the cement clinker,
t is a coefficient determined based on a temperature of 1450° C. (when a burning temperature is X° C., t=X/1450), and
HM is a hydraulic modulus.

2. The method for controlling a free lime content of a cement clinker according to claim 1 ,
wherein the amount of fluorine in the cement clinker is equal to or greater than 300 mg/kg.

Assignees

• Mitsubishi Materials Corp

Inventors

• Ninomiya Yuuki
• Tanaka Hisanobu
• Yamashita Makio
• Nakanishi Yoichiro

Classifications

• C04B7/361

  Condition or time responsive control in hydraulic cement manufacturing processes (controlling or regulating in general G05; F27B7/42 takes precedence) · CPC title

• C04B7/424 Primary

  Oxides, Hydroxides · CPC title

• C04B7/4407

  Treatment or selection of the fuel therefor, e.g. use of hazardous waste as secondary fuel (fuels in general C10L); Use of particular energy sources, e.g. waste hot gases from other processes · CPC title

• C04B7/421 Primary

  Inorganic materials · CPC title