Lead, use in batteries

Tellurium is used in the metallurgical industry as an alloy constituent. Tellurium improves the acid resistance of lead used in batteries. It is also used in the manufacture of heat- and abrasive-resistant rubber. Tellurium is obtained as a by-product in the electrolytic refining of copper. In the semiconductor industry, the ultra-trace level determination of tellurium in tellurium-doped single crystals is often required. Tellurium species are highly toxic. 

Lead consumption has become increasingly concentrated within the battery sector over the past thirty years, even as the growth of overall lead consumption has slowed, as Fig. 13.1 illustrates. In the six major consuming countries, lead use in batteries has risen from under 30 per cent of total consumption to almost two-thirds in the early 1990s. However, the proportion varies from as little as 35 per cent or so in the UK (and some other... 

In this context we can include laws which enforce the recycling of scrapped cars by domestic automobile manufacturers in Germany and pendii legisbtion in the USA which requires a given (and rising) proportion of lead used in battery manufacture to be recycled (see Chapter 20). 

Most uses of lead in chemical compounds other than in storage batteries are dissipative. The greater part of the lead used in other forms is recoverable. 

This operation is also performed using machines. The cured plates are fed into the parting machine by mechanical means. The plates are parted in the machine and then collected when the operation is completed manually. The parted plates are thereafter stacked for use in battery assembly. More rejects are also generated in this section as well as some lead dust. The ventilation system in this area ensures that the lead dust generated is removed from the work area and discharged into the atmosphere through a baghouse filter. 

Lead is produced from both primary (i.e., mined ore) and secondary (i.e., scrap metal and wastes) sources, and is imported by the United States. In 1997, production from primary and secondary sources was 343,000 metric tons and 1.1 million metric tons, respectively (Smith 1998), and imports reached 265,000 metric tons (Larrabee 1998 Smith 1998). Approximately 1.6 million metric tons of lead were consumed in the United States in 1997 (Smith 1998). Of lead used in 1997, 86.9% was used for storage batteries, 7.8% was used in metal products, and 5.3% was used in miscellaneous applications (Smith 1998). Because of the adverse health effects associated with exposure to lead, its use in paints, ceramic products, gasoline additives (now banned), and solder has declined dramatically in recent years. In 1997,... 

Combustion and explosion hazards of the powdered alloy used in batteries were studied. Increase in silver content leads to higher values of the ignition temperature and COI [1,2],... 

Lead is commonly obtained by roasting galena (PbS) with carbon in an oxygen-rich environment to convert sulfide ores to oxides and by then reducing the oxide to metallic lead. Sulfur dioxide gas is produced as a waste product. Large amounts of lead are also recovered by recycling lead products, such as automobile lead-acid electric storage batteries. About one-third of all lead used in the United States has been recycled. 

Antimony alloys have many commercial applications. The metal makes its alloys hard and stiff and imparts resistance to corrosion. Such alloys are used in battery grids and parts, tank linings, pipes and pumps. The lead plates in the lead storage batteries constitute 94% lead and 6% antimony. Babbit metal, an alloy of antimony, tin, and copper is used to make antifriction machine bearings. Alloys made from very high purity grade antimony with indium, gallium and bismuth are used as infrared detectors, diodes, hall effect devices and thermoelectric coolers. 

Lead (Pb) ranks fifth behind iron, copper, aluminum, and zinc in industrial production of metals. About half of the lead used in the U.S. goes for the manufacture of lead storage batteries. Other uses include solders, bearings, cable covers, ammunition, plumbing, pigments, and caulking. 

The four forms of lead are pure lead, also known as corroding lead (99.94%), common lead (99.94%), chemical lead (99.99) and acid-copper lead (99.99%). The resistance of lead to sulfuric acid enables its use in batteries. It is also used as sheet and pipe in buildings. The main use is as a solder material in the electronics industry. 

DOT CLASSIFICATION 8 Label Corrosive SAFETY PROFILE Poison by intraperitoneal route. Moderately toxic by ingestion. Human mutation data reported. A corrosive irritant to skin, eyes, and mucous membranes. Violent or explosive reaction with potassium. When heated to decomposition it emits very toxic fumes of Pb and SOx. Used in batteries, lithography, rapid-drying oil varnishes, weighting fabrics. See also LEAD COMPOUNDS and SULFATES. 

As of 2008, the largest producers of lead resources in the world included China, Australia, the United States, Peru, Mexico, Canada, and India. In the United States, most of the lead produced came ftom Missouri, Alaska, Idaho, Montana, and Washington. According to the U.S. Geological Survey (USGS), 88 percent of the lead used in the United States was used by the lead-acid storage battery industry. 

Lead is used in batteries, inorganic chemicals, pipes, solders, electric wires, etc., but batteries accounted for 72% of the total usage of lead in 1997. Therefore it can be said that batteries play an important role in the recycling of lead. Lead-acid batteries are classified into motor vehicle batteries (for automobiles and motorcycles), industrial batteries (stationary batteries, traction batteries, etc.), small-size sealed batteries (for UPS and consumer products). Table 2.1 shows their shipments. 

It may be noted that a substantial fraction of the lead in spent lead-acid batteries is recycled and not discarded. In the United States, about 95% of the lead used in lead-acid batteries is recycled (1989) and similar figures are likely to apply to other industrialized countries, if not now, then soon. In the case of Ni/Cd batteries, a smaller fraction is recycled, but that situation is likely to improve as more recycling facilities come on stream. The battery industry has made a concerted and relatively successful effort during the past decade to eliminate mercury from their products, and, in combination with mercury recycling, these efforts may be expected to significantly reduce the addition of mercury from batteries to communal waste streams. It becomes clear that the battery contributions to the overall problem is a matter of concern. The solution of the public health problem needs to be approached as a whole by extending the required treatments to cover all the sources of these public pollutants. 

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