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Table 2. Types of Lead Acid Batteries.
| Type |
Description |
Life Cycle (Years) |
| Automotive (SLI) |
Automotive batteries are constructed with thinly pasted plates and designed
to supply high peak currents for brief periods of time while cranking the
engine. They are not expected to be discharged to more than 75% of capacity and
are recharged immediately after use. This is the most common form of lead acid
battery. |
2 - 5 |
| Traction |
Traction batteries are made with thickly pasted plates and have
very rugged separators between the plates in order to make batteries more robust
to shock and vibration. These batteries are sold for use in electric forklifts,
golf carts, and marine trolling motors etc. Deep Cycle Marine batteries are of
this type. They are designed for deep discharges (possibly over the course of a
day), followed by deep recharges. |
4 - 6 |
| Stationary |
Stationary batteries are made with thick solid plates. They are
designed to be used as a standby power source and are kept in a state of nearly
full charge until needed. They are able to take a deep discharge, are bigger and
heavier than the other batteries and have a longer life time. |
up to 10 |
|
Sources: Kantor, 1997; UNEP, 1995; Vincent, Scrosati, Lazzari,
& Bonino, 1984
|
Figure 1. Constituents of Lead Acid Batteries (Percentage
Weight)
Source: Environment Canada, Hazardous Waste Division, Office of Waste
Management, 1993.
Step 1: Description of Technology
| a. Identify the nature and function of the technology: |
Name of the technology system: Hydrometallurgical processing of
spent lead acid batteries
Function of the technology: To recover high purity lead and other
valuable resources from used batteries, in an environmentally sound and
economically sustainable manner |
| b. Identify and characterize the existing or proposed location of the
technology: |
Site location: West Industrial Estate, Udanax City, Udanax
Surrounding land use: Industrial estate with mix of light and heavy
industry
Surrounding community: Beyond the estate, lower middle class
residences, mostly downwind from estate
Natural environment features: Flat land, with river adjacent to estate
Natural hazards: None of consequence |
| c. Describe the technology (check appropriate boxes) |
| Existing |
 |
Proposed |
 |
| Source of the technology |
Technology indigenous to the area
|
|
| Technology imported from abroad |
|
| Relatively new/unproven technology |
|
| Type of technology |
Based on the use of natural resources
|
|
| Processing/manufacturing |
|
| Service/infrastructure |
|
| d. In order of importance, identify the principal achievement goals
for this technology and the beneficiaries and stakeholders. |
|
What must the technology achieve?
|
Identify the beneficiaries & other stakeholders?
|
| 1. Economic return on the investment in the plant and
its operations |
Owners, financiers, plant operators, technology developers
and suppliers, central and municipal governments, plant workers |
| 2. Production of lead ingots, at a cost, and to the
specifications required for the efficient operation of the battery manufacturing
plant |
As above, but also owners and operators of the battery
manufacturing plant |
| 3. Operating a technology that can be sustained by
local resources |
As for Goal 1, but also people involved in the formal and
non-formal battery collection sectors in Udanax, and the Udanax public at large |
| 4. No or acceptable environmental (including
community) impacts from plant operations, and improved environmental quality due
to the elimination of poor environmental practices in the informal sector and
the removal of used batteries from the waste stream |
As for Goal 3, but also for other countries supplying used
batteries |
|
What other achievements are desirable?
|
Who are the beneficiaries/stakeholders?
|
| 1. Recycling of other components of a lead acid battery |
People involved in the formal and informal battery collection sectors,
users of the recycled materials, and the public at large. |
2.
|
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| 3. |
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| 4. |
|
e. Description of the technology
Briefly describe the overall operation of the technology, and any changes that
may need to be made to the technology during its operational lifecycle. Where
possible, list the operations in sequential order, following the production of a
product or service from start to finish.
|
Pre-treatment
- used batteries are taken from storage, manually removed from pallets and
packing materials, and placed on breaker conveyor belt;
- the acid is drained from the batteries, diluted with process water, the
acids is neutralised by the addition of alkali (e.g. limestone, lime, magnesia),
forming gypsum - controlled neutralisation produces a clean gypsum by-product
for use in some industrial applications such as plaster and cement production;
- batteries are broken using an automated mechanical breaking system that
crushes the batteries by means of a hammermill; the separated components are
classified and segregated;
- the grids, connectors and battery pastes are made ready for the lead
re-processing while the polypropylene battery cases are chipped, washed and then
fed into a standard plastic extrusion machine. The resulting plastic granulates
are stored in large bags for easy handing and subsequent recycling; other
plastics (polyvinyl chloride, ebonite), separators and other items are cleaned
and transported to the landfill waste disposal site;
Hydrometallurgical treatment of lead products
- grids, connectors and other metallic components are processed by low
temperature melting, producing alloyed lead and recyclable drosses; fume
captured in the ventilation bad filter is sent the electrotwinning line;
- desulfurisation of the battery pastes is achieved by mixing with an
alkaline solution regenerated through the addition of lime; clean gypsum is
again the by-product; thisby-product can be used in some industrial applications
such as plaster and cement production;
- the desulfurised battery pastes are leached with regenerated hydrochloric
acid, followed by purification with lead powder, lead electrowinning and
hydrochloric acid regeneration; feed materials can be battery pastes, fume,
ashes, drosses, old and new slags and lead concentrate;
- final products are lead ingots (99.99% lead), lead cement and residual
amounts of antimony, arsenic, copper, tin and selenium etc.; there are no waste
liquid effluents and only inert leaching residues
|
f. Flow diagram of the technology
Provide a flow diagram of the overall process or service, indicating the
various sub-processes/components, showing material, energy and water inputs and
output flows and identifying linkages between the different components and the
external environment. Complicated and detailed sub-process/components may be
drawn on additional sheets, if necessary.
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