Recovery and Processing

The major challenge to all recovery systems will be the increasing level of other plastic types in the feed material. Materials such as ABS (acrylonitrile butadiene styrene) are being used in VRLA battery cases, due to their toughness and rigidity relative to traditional polypropylene. For the recycler, this means that the valuable polypropylene tonnage will fall with a reciprocal increase in plastic types that cannot be recycled. This material will have to be disposed of, as ABS and 

Increased usage of other materials, such as silica compounds from AGM separators, can in fact benefit the secondary smelter. Larger amounts of the separator will help those smelters who use the silicate slag system, as less secondary silicate feed (sand) will be needed. 

It has been reported that silver decreases the rate of oxidation of lead, particularly in the Barton-pot process [25], by up to 10%. In the active materials, silver increases oxygen evolution (at the positive plate) more than it does to hydrogen evolution (at the negative plate). The promotion of gassing by silver, however, does not appear to be as serious a problem as was once thought, at least for materials with silver contents up to 0.01 wt.% [25]. 

The difficulty for secondary plants is that, whilst the de-silverizing process (outlined in Section 15.3) can be used for the removal of low levels of silver in secondary lead bullion (i.e., up to 0.01 wt.%), the same amount of zinc must be added as for primary bullion that contains up to 0.5 wt.% silver. With this method, silver cannot be removed economically from recycled lead, as the cost of zinc alone 

The problem facing all smelters is that there is a continuous occurrence of antimony in their lead streams, at a time when there is a rapidly declining demand for the element. Declining sales of the alloy, which coincide with increasing use of soft-lead-based alloys, will result in antimony effectively becoming a major contaminant that requires removal. Whilst it is relatively easy for secondary reflners to remove antimony from the bullion, the antimony-rich residue from the process may have to be stockpiled. The residue, which contains around 80 to 90wt.% lead, effectively ties up lead units and can have a major cost impact on the reflnery. 

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Iron [7439-89-6J, Fe, from the Latin ferrum, atomic number 26, is the fourth most abundant element in the earth s cmst, outranked only by aluminum, sihcon, and oxygen. It is the world s least expensive and most useful metal. Although gold, silver, copper, brass, and bron2e were in common use before iron, it was not until humans discovered how to extract iron from its ores that civilization developed rapidly (see Mineral processing and recovery). 

Fig. 2. Flow sheet for the acid circuit processing and recovery of mica from weathered granodiorite ore. An alkaline—cationic circuit may be used by inserting a second conditioner containing lignin sulfonate, adjusting the pH to 8.0, and adding NaOH and DRL (distilled tall oil) fatty acid to the first...

Processing and Recovery The functional element of processing and recoveiy includes all the techniques, equipment, and facilities used both to improve the efficiency of the other functional elements and to recover usable materials, conversion products, or energy from solid wastes. Materials that can be recycled are exported to facilities equipped to do so. Residues go to disposal. 

Their Significance in the Processing and Recovery of Plutonium and Other Actinides... 

The objective was to evaluate the potential of selected CMP type extractants for the processing and recovery of plutonium from nitric acid. 

Chabaux F, Cohen AS, O Nions RK, Hein JR (1995) 2 U- " U- °Th chronometiy of Fe-Mn crasts Growth processes and recovery of thorium isotopic ratios of seawater. Geochim Cosmochim Acta 59 633-638... 

Nonferrous metal hydroxide sludge wastes contain a large quantity of water, and the content of valuable metals is too small to allow economical smelting of these wastes. However, the wastes are a burden on the environment and they can only be deposited in special garbage dumps, which are very costly. Therefore a method for processing and recovery of the valuable materials and metal in the waste is highly desirable. 

Jager V (1992) In Kreysa G, Driesel AJ (eds) Microbial principles in bioprocesses cell culture technology, downstream processing and recovery. DECHEMA, Frankfurt am Main, p 265... 

The size of surfactant precipitate structures may vary widely, from colloidal precipitate, too small to be seen visually, to large crystals. This is an important property, because some deleterious effects of surfactant precipitation could be minimized or beneficial effects of precipitation could be negated if the precipitate were of colloidal dimensions. Examples of the importance of precipitate structure and size include the aforementioned oil field process and recovery of surfactant from surfactant-based separations via precipitation-fiItering. Effects of using surfactant mixtures on precipitate structures would be useful to know. 

Chemical Composition Information on the chemical composition of solid wastes is important in evaluating alternative processing and recovery options. If solid wastes are to be used as fuel, the six most important properties to be known are 1. Proximate analysis a. Moisture (loss at 105°C for 1 h)... 

If E is equal to Ew, no substance is lost during the process and recovery is 100%, but if E is smaller than some part of the pertracted compound is either adsorbed in the apparatus or left in the membrane phase. The latter effect can hmit the SLM pertraction in some cases. In practice, the problem can be overcome by carefiil design of the experimental conditions. 

Gebbert A et al 1992 Direct observation of antibody binding. Comparison of capacitance and refractive index measurement DECHEMA Biotechnol. Conf. 1992 vol 5, part A Microbial Principles in Bioprocesses Cell Culture Technology, Downstream Processing and Recovery pp 459-62 Stenberg M et al 1979 Silicon-silicon dioxide as an electrode for electrical and ellipsometrical measurements of adsorbed organic molecules J. Colloid Interface Sci. 72 255-63... 

Spielman A, Garn M B, Aellen T, Haemmerlil S and Widmer H M 1992 Flow injection analysis methods for on-line bioprocess monitoring the automated measurement of some basic medium components and an enzymic product Microbial Principles in Bioprocesses Cell Culture Technology, Downstream Processing and Recovery (DECHEMA Biotechnology Conf. 5, Pt A) pp 367-70... 

Murahdhara HS, Chauhan SP, Senapati N, Beard R, Jirjis B, Kim BC. Electro-acoustic dewatering (EAD) A novel approach for food processing, and recovery. Separation Science and Technology 23(12 13) 2143-2158, 1988. 

Where lower antimony slags are processed and recovery is not a critical issue, then more typical lead blast furnace slags can be used. Where feed has a significant sulfur content, iron can be added to capture the sulfur as a matte, and in this case relatively high iron slags can be produced with Fe0 Si02 ratios above 2.0 and Ca0 Si02 ratios below 0.5. 

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