Liquid purification or separation – Processes – Using magnetic force
Reexamination Certificate
2005-05-24
2005-05-24
Hruskoci, Peter A. (Department: 1724)
Liquid purification or separation
Processes
Using magnetic force
C210S705000, C210S711000, C210S713000, C210S714000, C210S725000, C210S727000, C210S912000, C210S913000, C210S914000
Reexamination Certificate
active
06896815
ABSTRACT:
A two-step chemical precipitation process involving hydroxide precipitation and sulfide precipitation combined with “field separation” technology such as magnetic separation, dissolved air flotation, vortex separation or expanded plastics flotation, effectively removes chelated and non-chelated heavy metal precipitates and other fine particles from water. In the first-step, the non-chelated heavy metals are precipitated as hydroxides and removed from the water by a conventional liquid/solids separator such as an inclined plate clarifier to remove a large percentage of the dissolved heavy metals. The cleaned water is then treated in a second precipitation step to remove the residual heavy metals to meet discharge limits. In the second precipitation step, any metal precipitant more effective than hydroxide for metal precipitation can be used. The invention improves metal removal, lowers cost because fewer chemicals are used, produces less sludge, and reduces the discharge of toxic metals and metal precipitants to the environment.
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Angeli Michael de
Hruskoci Peter A.
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