Environmental Engineering FOURTH EDITION

Reuse, Recycling, and Resource Recovery 285

1 ~

0 100

Recovery of inorganics in the

reject stream ("A)

Figure 14-10. Actual and ideal performance of air classifiers. Idealized curves,

terminal settling curves as shown in Fig. 14-9. What would be the recovery of organic
material, and what would be the purity of the recovered product?
Since each component is 25% by weight of the feed, xo = 25% + 25% = 50%
and yo = 25% + 25% = 50%. From Fig. 14-9, at 200 cds air velocity, the fractions
of the components in the overilow (product) are:

Paper 100%

Plastics 80%

Aluminum 50%

Steel 0%

Thus the total percentage of organic materials in the product (XI in Eqs (14.6H14.8)) is

(loo)($) + (go)($) = 45%,

and the percentage of inorganic materials in the product 01 in Eq. (14.7)) is

(50)($) i- (O)($) = 12.5%.

From Eq. (14.6), the recovery of organic materials is

R,=- 45 (100) = 90%,

25 + 25

and the purity is

(100) = 78%.

45

45 + 12.5

Porgpmduct =