Environmental Engineering Reference
In-Depth Information
about the environmental impacts of the wastes is
also important for convincing people to implement
the suggested alternative waste management solu-
tions, which can be considered as a new way of
achieving better working conditions in the facility.
This study focuses on the wastes produced in three
manufacturing processes as shown in Figure 1:
grid casting, battery closing, wet-charging. Due
to the current waste management system of the
company, the identified wastes are considered as:
benefits and limitations are identified for each
solution alternative.
Alternative Waste Management
Solutions: Wastes from Grid Casting
Dross obtained from the grid casting process is
the waste that causes the highest lead loss in the
company. In the grid casting process, the excess
parts of each grid are cut automatically and
transferred to the melting pot by a conveyor belt
located behind grid casting machines. Addition-
ally, the rejected grids detected by operators are
added to the melting pot immediately after their
detection. Therefore, the grid casting process
involves continuous addition of wastes into the
melting pot. The formation of dross is the result of
molten lead alloy and air contact. It is simply the
oxidation of lead alloy. Therefore, the formation
of dross is inevitable on the surface of the molten
lead alloy in the pot that is open to atmosphere.
In fact, the dross formed may act as a protective
passive film preventing further dross formation
if it is not disturbed. But, when wastes deriving
from the grid casting machine are added to the
melting pot continuously, the surface covered
by dross collapses, and this procedure causes an
increase in contact area of lead alloy with air. As a
result, the amount of dross increases continuously
when wastes are added to the pot. There are two
alternative practice identified for the reduction
of dross amount in this study as explained and
analyzed below.
Addition of Excess Parts and Rejected
Grids in Batch Mode:
The practice of adding
excess parts and rejected grids may be changed
from continuous to batch. In other words, the
parts and grids may be collected and then added
at specific time intervals, so that the contact time
of the molten lead alloy with air can be decreased.
This practice is experimented in the grid casting
procedure to observe any change of dross forma-
tion rate in this study.
•
On-site recycled wastes:
Wastes used
within the facility.
•
Off-site recycled wastes:
Wastes sent
to recycling facilities to recover the raw
material.
•
Wastewater:
Contaminated water treated
in the wastewater treatment facility of the
company
Identification of Alternative
Waste Management Solutions
The alternative waste management solutions are
identified by investigating waste management
technologies and alternative waste manage-
ment solutions. The possible waste management
technologies in the battery manufacturing plant
are identified and the benefits of implementing
pollution prevention techniques in the considered
sector are investigated. The best available tech-
nologies aiming the decrease of particular types
of wastes are described in detail in the evaluation
of alternative waste management solutions inves-
tigated for the considered wastes. Additionally,
two case studies concerning a general pollution
prevention study in the car battery manufacturing
industry are examined. The applicability of each
alternative waste management solution is evalu-
ated in order to show the type of problems that
could derive from their applications. By making
an operational, technical and economical analysis
for each of the alternatives, it is possible to pres-
ent realistic propositions. Therefore, the possible
