US 5,175,134 AGranted

Ceramic tile produced from sludge slag

AssigneesSenji Kaneko, Takashi Shindo, NKK Corporation, Shinagawa Shirorenga Kabushiki Kaisha

InventorsSenji Kaneko, Takashi Shindo, Atsuo Inokawa, Yasushi Hoshino, Takashi Otsuka, Katsuhiro Wakasugi, Masaru Takikawa

Life of this patent

Estimating the term…

patentgrep

Loading patent…

Abstract

The ceramic tile using sludge slag of the present invention comprises: ______________________________________ sludge slag from 5 to 70 wt. %, agalmatolite from 20 to 90 wt. %, clay from 5 to 50 wt. %, and the balance being incidental impurities. ______________________________________ The sludge slag is obtained by separating sludge from sewage, burning the thus separated sludge into ash, melting the resultant ash and solidifying the thus melted ash. The sludge slag consists essentially of: ______________________________________ silicon dioxide (SiO.sub.2) from 10 to 50 wt. %, aluminum oxide (Al.sub.2 O.sub.3) from 3 to 20 wt. %, phosphorous pentoxide (P.sub.2 O.sub.5) from 1 to 30 wt. %, calcium oxide (CaO) from 10 to 70 wt. %, magnesium oxide (MgO) from 0.5 to 20 wt. %, and iron oxide (Fe.sub.2 O.sub.3) from 5 to 25 wt. %. ______________________________________

Claims13

Dependent claims

A ceramic tile produced by

(i) mixing composition which comprises:
(a) a sludge slag obtained by separating sludge from sewage, burning the thus separated sludge to form an ash, melting said ash and solidifying the thus melted ash:
from 5 to 70 wt. %,
(b) agalmatolite:
from 20 to 90 wt. %,
(c) clay:
from 5 to 50 wt. %, and
(d) the balance being incidental impurities,
where the total amount of sodium oxide (Na.sub.2 O) and potassium oxide (K.sub.2 O) as said incidental impurities being up to 5 wt. %;
and
said sludge slag consisting essentially of;
silicon dioxide (SiO.sub.2):
from 10 to 50 wt. %,
aluminum oxide (Al.sub.2 O.sub.3):
from 3 to 20 wt. %,
phosphorus pentoxide (P.sub.2 O.sub.5):
from 1 to 30 wt. %,
calcium oxide (CaO):
from 10 to 70 wt. %,
magnesium oxide (MgO):
from 0.5 to 20 wt. %, and
iron oxide (Fe.sub.2 O.sub.3):
from 5 to 25 wt. %,
wherein said calcium oxide (CaO) content to said silicon dioxide (SiO.sub.2) content being in a ratio within a range of from 0.2 to 7.0, and
said sludge slag having a melting point within a range of from 1,120.degree. to under 1,200.degree. C.;
and
(ii) firing the composition to produce a ceramic tile.

24 more elements

Dependencies are inferred from the claim text.