Storage battery manufacture

The most important oxides of lead are litharge (PbO), lead dioxide (Pb02) and red lead (Pb304). Black oxide (a mixture of 60-80% PbO with finely divided metallic lead) is used in the manufacture of lead-acid batteries (see Section 5.1.2.2), and in 1975 in the US approximately 70% of lead used in oxides and pigments was used for storage battery manufacture. The estimated emission of lead to the atmosphere from manufacture of the lead oxides and pigments was 112 tonne y [1]. 

Both litharge and black oxide are prepared in processes involving the oxidation of metallic lead. The properties of the exhaust gases from production of black oxide by the ball mill or Barton process are shown in Table 5.7. A fabric filter (or baghouse) is an essential part of plant design and the quoted emission factor is determined after passage through the filter. 

The more important lead pigments are red lead (Pb304), white lead (mainly 2PbC03 2Pb(0H)2) and lead chromate (PbCr04). The quantities produced are rather modest and hence any pollution problems are liable to be of a very localized nature. 

Manufacture of lead-acid storage batteries is a major use of lead, but only a rather minor contributor to atmospheric pollution. 

The plates used in lead-acid batteries are made from moulds cast from a lead alloy which are coated with paste consisting of a mixture of black powder 

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The following Is a hypothetical example of how one manufacturer might complete the toxic chemical release inventory reporting Form R. The facility information is purely fictitious and does not represent any known manufacturing facility. The example begins with descriptions of the facility (a lead-acid storage battery manufacturer) and of the production process at the faciiity. The completion of each section of Form R is explained and a copy of Form R, as it would be completed by this facility, follows. 

About 4 million tons of lead are refined annually worldwide (Table 4.1). Domestic lead consumption is 1.3 million tons annually, of which about half is used in storage battery manufacture... 

Cadmium casting Cadmium smelting Cadmium spraying Copper-cadmium melting Heating of cadmium-plated steel Revert annealing Storage battery manufacture... 

Table 3.3 shows continuing trends upward for some consumption categories and declines in other categories. The continuing upward trend for lead use in storage battery manufacture is notable. 

N. E. Hehner, Storage Battery Manufacturing Manual, Independent Battery Manufacturers Association (IBMA), Largo, Fla., 1976. 

Zinc is also used extensively to galvanize other metals such as iron to prevent corrosion. Zinc oxide is a unique and very useful material for modern civilization. It is widely used in the manufacture of paints, rubber products, cosmetics, pharmaceuticals, floor coverings, plastics, printing inks, soap, storage batteries, textiles, electrical equipment, and other products. Lithopone, a mixture of zinc sulfide and barium sulfate, is an important pigment. 

Its alloys include solder, type metal, and various antifriction metals. Great quantities of lead, both as the metal and as the dioxide, are used in storage batteries. Much metal also goes into cable covering, plumbing, ammunition, and in the manufacture of lead tetraethyl. 

Lead dioxide is electrically conductive and is formed ia place as the active material of the positive plates of lead-acid storage batteries. Because it is a vigorous oxidizing agent when heated, it is used ia the manufacture of dyes, chemicals, matches (qv), pyrotechnics (qv), and Hquid polysulfide polymers (42) (see Polypous containing sulfur). 

Lead Tetroxide. Lead tetroxide (red lead minium lead orthoplumbite), Pb O, is a brilliant orange-red pigment which accounted for U.S. shipments of 17,780 t ia 1977, mainly to the ceramics and storage battery iadustries (40). U.S. shipments ia 1993 amounted to approximately 12,000 t. The decrease ia usage siace 1973 (19,000 t) is attributable to discontinued use ia the paint and coatings (qv) iadustry, and alterations ia mbber and ceramics (qv) markets. It is iasoluble ia water and alcohol, and dissolves ia acetic acid or hot hydrochloric acid. Red lead is manufactured by heating lead monoxide ia a reverberatory furnace ia the preseace of air at 450—500°C uatil the desired oxidative composition is obtaiaed. 

Direct Current (DC). This current is transmitted for industrial uses only in exceptional situations. The most common sources of direct current are storage batteries and industrial devices called rectifiers, in which alternating current is changed (rectified) to direct current, as is used in electrolytic cells for the manufacture of chlorine gas, magnesium, aluminum, and a few other chemicals. The direct current is flowing from the source through the user application and back to the source, in one direction. The motor is primarily used for speed control of selected equipment. 

Because of these damaging effects, most uses of lead that involve direct exposure for humans are being phased out. Unleaded gasoline and lead-free paints have replaced two former major commercial uses of lead. Lead has proved to be Indispensable, however, in the lead storage battery, which now provides the major use of this metal. Although leakage from damaged batteries is still a potential hazard, contemporary batteries are manufactured in such a way that human exposure to battery contents is minimized. 

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