Methods for the control of excessive corrosion in phosphoric aci

Details Methods for the control of excessive corrosion in phosphoric aci Methods for the control of excessive corrosion in phosphoric aci

1979-09-18

1981-07-07

Richman, Barry

Chemistry of inorganic compounds

Phosphorus or compound thereof

Oxygen containing

23230A, 23230R, 204147, 422 3, 422 12, 423 10, 423 18, C01B 25225, C01B 25226, C23F 1104

Patent

active

042774543

ABSTRACT:
Methods for control of excessive corrosion in wet process phosphoric circuits are effected by oxidation of reduced ion species in the acid with maintenance of EMF value of the acid above about 190 millivolts (S.C.E. reference) through the digestion circuit. Supplementary monitoring is by a ceric red-ox titration procedure. In one embodied form, the present invention is utilized to control corrosion in a phosphoric acid plant digestion system (and subsequent processing equipment) operating by a dihydrate (gypsum) process even when such a process employs a calcined western U.S. phosphate ore feed from a relatively highly carbonaceous ore. The invention is also applicable for treating wet process phosphoric acid in phosphoric acid plants having a digester system operating by a hemihydrate process. In a presently preferred embodiment, additions of manganese dioxide to a primary digester in a sufficient amount effective to achieve an EMF value over about 190 millivolts will significantly control the occurrence of excessive corrosion in phosphoric acid circuits. In yet another preferred embodiment, an oxygen autoclave oxidation is used to oxidize the reduced ion species present in the acid to inhibit corrosion.

REFERENCES:
patent: 2854497 (1958-09-01), Piehl
patent: 3027236 (1962-03-01), Cosway et al.
patent: 3116178 (1963-12-01), Upham
patent: 3649167 (1972-03-01), Sawyer
patent: 3935298 (1976-01-01), Sugahara et al.
patent: 4101638 (1978-07-01), Knoue et al.

Affiliated with

Also associated with

Rating

Methods for the control of excessive corrosion in phosphoric aci does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Methods for the control of excessive corrosion in phosphoric aci, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Methods for the control of excessive corrosion in phosphoric aci will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-193713