Production, Use, and Recycling

Production, Use, and Recycling In the US, almost all beryllium is purified from a large deposit of bertrandite that occurs at Spor Mountain, Utah. While this ore only contains 0.6% beryllium, extraction of the metal from this ore is easier than the extraction of beryllium from beryl (14% 

BeO) because the beryllium in bertrandite is acid-soluble (Stonehouse and Zenczak 

Bertrandite is wet-milled to produce a slurry of fine particles, and then leached with sulfuric acid near the boiling point. 

The aqueous beryllium sulfate is separated from the solids by counter-current decantation thickener operations. A beryllium concentrate is produced by a counter-current solvent extraction process (Maddox and Foos 1966). This concentrate is stripped of its beryllium content with aqueous ammonium carbonate. By heating to 70 °C, aluminum and iron are precipitated and then removed by filtration. Precipitation of beryllium basic carbonate occurs when the solution is heated to 95 °C. The carbonate is filtered, deionized water is added, and heating to 165 °C yields a beryllium hydroxide product which is the common input to beryllium-copper alloy, beryllium oxide ceramics, or pure beryllium metal (Table 2.1-2). 

Metal 10% of total Aircraft disk brakes, X-ray transmission windows, space-vehicle optics and instru-usage ments, aircraft/satellite structures, missile parts, nuclear-reactor neutron reflectors, 

---

Environmental Impacts of Use and Recycling of Additives (DEHP) in Products... 

Within the broad framework of sustainable development, we should strive to maximize resource efficiency through activities such as energy and nonrenewable resource conservation, risk minimization, pollution prevention, minimization of waste at all stages of a product life-cycle, and the development of products that are durable and can be re-used and recycled. Sustainable chemistry strives to accomplish these ends through the design, manufacture and use of efficient and effective, more environmentally benign chemical products and processes". 

Air streams from the digestion system, vacuum cooler, concentrator, and other areas where fluorine is evolved are connected to a highly efficient absorption system, providing extremely high volumes of water relative to the stream. The effluent from this absorption system forms part of the recycled water and is eventually discharged as part of the product used for fertilizer manufacture. The Minnesota plant requires a constant recirculating water load in excess of 3000 gpm (11.4 m /min), but multiple use and recycle reduce makeup requirements to less than 400 gpm (1.5 m /min) or a mere 13% of total water use. 

Workers may be exposed to ENMs during the production, use, or recycling of industrial nanoproducts, and consumers may be exposed mainly during the use of consumer products. However, sooner or later these ENMs are likely to enter the environment and therefore assessing occupational and consumer exposure forms the basis for assessing the environmental exposure. Direct exposure of the environment to ENMs will be mainly restricted to a few applications with intended release... 

An enantioselective one-pot, three-component imino-Reformatsky reaction has been reported.20 Combining a benzaldehyde, an aniline, and an alkyl bromoacetate ester, (g) ees of up to 92% have been achieved in the /i-amino ester product, using a recyclable A-methylcphedrinc as auxiliary. A nickel(II) salt and dimethylzinc are employed the latter serves as dehydrating agent, reductant, and coordinating metal. 

In some cases, green reactions are based on feedstocks derived from renewable resources that produce highly pure compounds. Another green option is the use of supercritical fluids that are more benign substances (e.g., water, carbon dioxide, and light nonhalogenated hydrocarbons) such fluids can be used as solvents for separations or as media for reactions, and can be easily recovered from the product mixture and recycled. We can also include here the use of ionic systems of nonvolatile salts that are molten at ambient temperature, and that act as solvents or even have a dual role (as catalysts and solvents), without the risk of unwanted vapors. These ionic solvents replace the more hazardous, volatile, and expensive organic solvents used traditionally. 

Recovery of catalyst. Many reactors use catalysts to increase the rate of the reaction. Catalysts are usually expensive, and the processes generally include provisions for recovering them from the product stream and recycling them to the reactor. They may be recovered with the unconsumed reactants or recovered separately in special facilities designed for this purpose. 

Two definitions of reactant conversion are used in the analysis of chemical reactors with product separation and recycle of unconsumed reactants ... 

Figure 23. Current use and recycling of by-products and wastes from oil palm plantings and conventionai paim oil milling (144).

Numerous studies of paper production, use, and disposal have also been done. One of the more interesting is an extensive examination of paper recycling conducted by a team in England. In this study, that included consideration of LCI data as well as an economic assessment, the following options were compared ... 

Under raw material consumption, the mass of raw materials needed by the corresponding process is determined first. The individual materials are weighted according to their reserves. The toxicity potential is calculated using the classifications for hazardous materials under EU law. The abuse and risk potential refiects the dangers of accidents in the manufacture, use and recycling of the product. The approach adopted is similar to a risk assessment in the case of plant safety in which the probability of occurrence and the level of damage are estimated. Values used for the individual products are only comparative and not absolute. 

---