Environmental Engineering Reference
In-Depth Information
significant amount of recovery of lead from the
dross.
Experiments conducted in the company for re-
covering lead from dross showed that the quantity
of the dross decreases by 30% when pure lead is
separated from dross with the help of Vitaflux™.
In other words, this alternative involves 30% of
reduction of dross at source. Therefore, even if
the impact to the environment can not be quanti-
fied, the company's damage to the environment
is certainly decreased on a large scale since the
dross deriving from grid casting is the highest
amount of waste in the company. In addition and
more importantly, a significant quantity of pure
lead is going to be saved and will be used in
production. As a result, this alternative allows a
more efficient use of raw materials and a decrease
in total recycling costs. The net present values of
the current system and the Vitaflux alternative are
calculated for one year in Table 2.
In addition to the current system, in the Vita-
flux alternative there is a need of extra labor time
when mixing the pot and collecting the dross
after the addition of Vitaflux. Dross is collected
once in 24 hours from 2 melting pots. In the cur-
rent system, the collection of dross from one pot
takes 10 minutes. Taken into basis that the com-
pany works 24 hours during 29 days/month, it is
calculated that the monthly labor spent for in the
current case is 10 hours. Since the unit labor cost
is 1.6 $/hour, the labor cost associated to this
alternative is: C Labor Cost of Current System=
1.6 $/hour x 10 hours/month = 16 $/month.
The same calculation is made for the Vitaflux
alternative taking into basis that the collection of
dross from one pot takes 20 minutes. On the other
hand, the period in which Vitaflux™ is bought
and the quantity of Vitaflux™ needed in this time
period is important. It is calculated that 3 month
purchasing period gives the minimum net present
value. The monthly interest rate is taken as 1.6%.
When comparing net present values, it can be seen
that the Vitaflux alternative decreases costs by 17%
compared to the current system. Since the amount
of dross is assumed to be equal to the lead alloy
loss, it can be concluded that 3,690 kg/month of
lead can be recovered and used in production with
the Vitaflux™ application.
Alternative Waste Management
Solutions: Setup Wastes Generated
From Battery Closing Operation
Minimization of setup time may correspond
to reduction of setup wastes for the industries
producing sequential products requiring similar
production techniques. One way of decreasing
setup waste may be to decrease the number of
machine adjustments in the productions, where
the number of setup waste is constant according
to quality regulations. The production scheduling
policy used in most of the industries is based on a
system where monthly demands are divided into
short sub-periods in order to increase the flex-
ibility of the production. However this may cause
production of abundant numbers of setup waste
Table 2. Comparison of cash flow analysis of the current system and the Vitaflux alternative
Current System
Vitaflux Alternative
Quantity of dross (kg/month)
12,299
8,609
Cost of raw material loss ($/month)
14,605
10,224
Labor cost associated to the collection of dross ($/month)
16.25
32.5
NPV of Vitaflux for 3 months purchasing period
-
19,465*
Net Present Value ($/year)
158,492
130,648
