Recycling of lead

Secondary lead production made up over 70% of the lead produced in the United States in 1992 vs 54% in 1980. The amount of secondary lead produced was 698 X 10 t in 1988, 888 x 10 t in 1990, and 878 x 10 t in 1992. Of the 1.2 x 10 t of lead consumed in the United States in 1992, approximately 880,000 t were produced from the recycling of lead—acid batteries and 350,000 t from primary sources. A similar trend exists worldwide. In 1992, for the first time, slightly over half (51%) of the lead produced in the world came from secondary sources. 

The U.S. is the world s largest recycler of lead scrap and is able to meet about 72% of its total refined lead production needs from scrap recycling. The secondary lead industry consists of 16 companies that operate 23 battery breakers-smelters with capacities of between 10,000 and 120,000 t/yr five smaller operations with capacities between 6000 and 10,000 t/yr and 15 smaller plants that produce mainly specialty alloys for solders, brass and bronze ingots, and miscellaneous uses. 

Although lead has been classified for many years as a hazardous product, the main driver behind the recycling of lead-acid batteries is the value of lead as a tradeable commodity. Lead and its products form part of the scrap-metal family (with aluminium, zinc, and copper and its alloys) that has been the focus of scrap-metal merchants for many years. Throughout the world, efficient scrap networks and channels exist to supply the recycler with raw materials such as aluminium cans, copper wire, and lead-acid batteries. 

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. 

Recycling of Lead-Acid Batteries for Automobiles and Motorcycles... 

The Italian Way to the Collection and Recycling of Lead/Acid Accumulators... 

Although the hydrometallurgical process is more complicated than the thermal process, its principal virtue resides in the essential recovery of all of the materials in spent lead-acid batteries, including the plastic materials, and in the minimal generation of waste streams. As actufd data become available on the operational characteristics and the economics of full scale plants, it will be possible to make a meaningful assessment of this process and its merits relative to other processes for the recycling of lead-acid batteries. 

The profitability of the recycling of lead accumulators and Ni-Cd accumulators depends on the metal prices. Due to fluctuations it swings between losses and profits. The recycling process for mercury button cells and for Mn02-Zn primary cells require financial subsidues. 

Lead—acid batteries are mono-metallic. All active materials, plate grids, straps and connectors are made mostly of lead. Hence, recycling of lead from batteries is an easy process. Many countries have national lead pools (comprising production of primary lead and recycling of secondary lead). Schematics of the operation of a national lead pool is presented in Fig. 4.2. 

Khosla, N. and Leming, M., Recycling of lead-contaminated blasting sand in construction materials, in Proc. SSPC Lead Paint Removal Symposium, Steel Stractures Painting Council, Pittsburgh, PA, 1988. 

The refining of lead is also highly dispersed. Refined lead is produced in almost all countries of reasonable size, but only in thirty or so in any great volume. The recycling of lead is relatively well-developed, certainly when... 

The recyclability of lead is probably its most positive attribute. More than one half of Western World refined lead is now produced from recycled scrap in various forms. This proportion is well above that of other major metals and most other industrial raw materials. As we have seen, lead recycling will grow in importance in the future based essentially on a continued expansion of lead-acid battery usage. Secondary production not only removes used (potential waste) products from the environment, but is also intrinsically more energy efficient than metal production from lead ores and concentrates. For instance, the production of lead ingot from battery scrap uses only about one-third of the energy required in primary metal production. ... 

Concerns about the effects of cadmium and lead heat stabilizers on human health and the environment, and the probabilities of replacement, date back at least three decades. Pressures to eliminate the environmental hazards ostensibly caused by lead exposure have led to the introduction of a Senate bill calling for reductions in commercial and personal consumption of lead and its compounds. The measures would ban lead in food processing and cans, phase-out lead in cosmetics and product packaging, and require 100 percent recycling of lead-acid storage batteries. 

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