Nickel-cadmium battery plants

Waterfowl feeding in areas subjected to extensive nickel pollution — such as smelters and nickel-cadmium battery plants — are at special risk because waterfowl food plants in those areas contain 500 to 690 mg Ni/kg DW (Eastin and O Shea 1981). Dietary items of the ruffed grouse (Bonasa umbellus) near Sudbury, Ontario, had 32 to 95 mg Ni/kg DW, whereas nickel concentrations in grouse body tissues usually contain less than 10% of the dietary level. Nickel concentrations in aspen (Populus tremula) from the crop of ruffed grouse near Sudbury ranged from 62 mg/kg DW in May to 136 mg/kg DW in September (Chau and Kulikovsky-Cordeiro 1995), which shows the role of season in dietary nickel composition. 

New York Hudson River near nickel-cadmium battery plant 1972 ... 

Nickel concentrations are comparatively elevated in aquatic plants and animals in the vicinity of nickel smelters, nickel-cadmium battery plants, electroplating plants, sewage outfalls, coal ash disposal basins, and heavily populated areas. For example, at Sudbury, Ontario, mean nickel concentrations, in mg/kg DW, were 22.0 in larvae of aquatic insects, 25.0 in zooplankton, and 290.0 in aquatic weeds maximum concentrations reported were 921.0 mg/kg DW in gut of crayfish (Cambarus bartoni) and... 

Concentrations of nickel in roots of Spartina sp. from the vicinity of a discharge from a nickel-cadmium battery plant on the Hudson River, New York, ranged between 30.0 and... 

Cadmium production is related to its use in electrochemical plants for metal galvanization (about 50%), for nickel-cadmium batteries and special alloys. 

Despite the fact that cadmium is very toxic and that the number of batteries based on this metal (i.e. nickel-cadmium cells) is very significant, there are very few recycling plants in operation. One very effective recycling process has been designed and developed by SAFT NIFE AB in Sweden to treat both industrial and consumer nickel-cadmium batteries. The flow... 

Even when considered on a long term basis, there is considerable doubt that the presence of land filled battery metals such as lead, zinc, and cadmium would have the catastrophic environmental effects which some have predicted. Studies on 2000-year old Roman artifacts in the United Kingdom (Thornton 1995) have shown that zinc, lead and cadmium diffuse only very short distances in soils, depending on soil type, soil pH and other site-specific factors, even after burial for periods up to 1900 years. Another study in Japan (Oda 1990) examined nickel-cadmium batteries buried in Japanese soils to detect any diffusion of nickel or cadmium from the battery. None has been detected after almost 20 years exposure. Further, it is unclear given the chemical complexation behavior of the metallie ions of many battery metals exactly how they would behave even if metallic ions were released. Some studies have suggested, for example, that both lead and cadmium exhibit a marked tendency to complex in sediments and be unavailable for plant or animal uptake. In addition, plant and animal uptake of metals such as zinc, lead and cadmium has been found to depend very much on the presence of other elements such as iron and on dissolved organic matter (Cook and Morrow 1995). Until these behavior are better understood, it is unjustified to equate the mere presence of a hazardous material in a battery with the true risk associated with that battery. Unfortunately, this is exactly the method which has been too often adopted in comparison of battery systems, so that the true risks remain largely obscured. 

The first plants designed to recover the cadmium from nickel-cadmium batteries appear to have started up in the early 60 s. These plants used distilling furnaces... 

It was in the 80 s that plants specifically designed for the processing of batteries and waste from nickel-cadmium batteries came into their own. 

In Japan, NIPPON RECYCLE CENTER developed its process in the 70 s, although its dedicated plant specifically designed to treat nickel-cadmium batteries only came into operation in Korea in 1984. 

No plant recycling nickel-cadmium batteries currently uses this type of process, not just because of the risks of explosion, but also because of the difficulty of capturing the particles. The standards in respect of the cadmium content of the air in treatment plants reach exposure limit values that it is very hard to comply with. 

The SAFT AB recycling plant at Oskarshamn/Sweden is fully integrated in the manufacturing plant for industrial nickel-cadmium batteries. It demonstrates the commitment of the major european NiCd battery producer to control the life-cycle of the products introduced on the market. Process development started in 1978 and the operation reached industrial scale in 1986 (Figure 6). 

S.N.A.M. was created in 1977, with a major activity in the extraction of the cadmium contained in waste originating from the production or recovery of nickel cadmium batteries. The first plant has been in operation at St Quentin Fallavier (Isere - France). The plant has received authorisation for the treatment of 1,500 tonnes of cadmium containing by-products. 

Cadmium ranks close to lead and mercury as a metal of current toxicological concern. Cadmium is used in electroplating and galvanization, and in plastics, paint pigments (cadmium yellow), and nickel-cadmium batteries. Because <5% of the metal is recycled, environmental pollution is an important consideration. Coal and other fossil fuels contain cadmium, and their combustion releases the element into the environment. Extraction and processing of zinc and lead also lead to environmental contamination with cadmium. Workers in smelters and other metal-processing plants may be exposed to high concentrations of cadmium in the air however, for most of the population, food is the major source of cadmium. 

Cadmium is a soft, ductile, bluish white metal. It may be alloyed with lead, tin and bismuth in the manufacture of fusible metals for automatic sprinkler systems, fire alarms and electrical fuses. Cadmium has been used as a control or shielding material in atomic energy plants because of its high absorption of low-energy neutrons. Nickel-cadmium batteries are in common use for specialized purposes, but intensive research is going on in order to develop a more ecofriendly anode material as an alternative to cadmium. 

Of the conventional secondary systems, the nickel-iron and the vented pocket-type nickel-cadmium batteries are best with regard to cycle life and total lifetime. The nickel-hydrogen battery developed mainly for aerospace applications, has demonstrated very long cycle life under shallow depth of discharge. The lead-acid batteries do not match the performance of the best alkaline batteries. The pasted cells have the shortest life of the lead-acid cells the best cycle life is obtained with the tubular design, and the Plante design has the best lifetime. 

Cadmium is a widely distributed metal used in manufacturing and is present in a number of consumer products. Dietary exposure to cadmium is possible from shellfish and plants grown on cadmium-contaminated soils. Absorption is increased when associated with low levels of iron or calcium in the diet. Some plants, such as tobacco, can concentrate cadmium from even low levels in the soil. The lung readily absorbs cadmium, thus cigarette smokers have elevated cadmium exposure. Cadmium is also used as a metal alloy, in paint, and in batteries (Ni-Cad, nickel-cadmium). Workplace exposure can occur in welding and battery manufacture. 

In 1990, Sanyo and Matsushita initiated large-scale commercialization of small sealed nickel-metal hydride batteries. They are now joined by Dur-acell, Toshiba and Varta in a consortium which is known as the 3C alliance (camcorders, cellular telephones and computers). Several plants have been commissioned which are each producing 100-200 million cells per annum. It is forecast that nickel-metal hydride may overtake nickel-cadmium before the end of the century. In addition to the 3Cs nickel-metal hydride cells are used for a wide variety of cordless consumer products, communications equipment and other high rate long cycle life applications. 

At the present time, a large number of spent batteries are disposed of directly into the urban waste stream without proper controls. In addition to the most common systems such as zinc-carbon, alkaline manganese and nickel-cadmium, these now include, at an increasing rate, nickel-metal hydride and lithium cells. Such disposal is of serious concern because of the possible effects of battery components on the environment. Consequently, most countries are now evolving policies for collection and recycling. The majority of lead-acid batteries are recycled, but the number of recycling plants in operation worldwide for other battery systems is still very small due to the unfavourable economic balance of such operations (see Table A3.1). Some of the procedures for the disposal and recycling of battery materials are now briefly described. 

In Japan, in the late 80 s, TOHO ZINC set up a plant for the pre-treatment of batteries and nickel-cadmium waste this was designed to produce an impure cadmium oxide to be used in its primary cadmium production process. 

---