Chemistry: fertilizers – Processes and products – Organic material-containing
Patent
1997-06-06
2000-02-22
Straub, Gary P.
Chemistry: fertilizers
Processes and products
Organic material-containing
71 12, 71 13, 71 15, 588236, 210912, 210724, 423 27, 423 68, 423 98, 423109, C05F 1108, B01D 2102, B01D 1100, A62D 300
Patent
active
06027543&
ABSTRACT:
A method for removing a heavy metal from sludge, including the step of putting the sludge into contact with a treating liquid to dissolve the heavy metal contained in the sludge into the treating liquid. The treating liquid is formed of either A or B, where (A) is an aqueous solution of phosphoric acid, and (B) is an aqueous solution of phosphoric acid containing at least one of B1 and B2, where (B1) is at least one acid other than phosphoric acid, and (B2) is at least one oxidant. The concentration of the phosphoric acid in the treating liquid is 3% by weight or more. Alternatively, the sludge is put into contact with the treating liquid at a temperature of 40.degree. C. or higher.
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Tomida Tahei
Yoshizaki Shiro
Straub Gary P.
Wong Melanie C.
Yoshizaki Shiro
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