Silver content

In both preceding cases, the demands to the electrolysis unit are limited, since there is no need to keep the silver content in the fixer tank constantly low. A steady state silver concentration in the fixer between 3 and 5 g/1 is acceptable, since this causes no substantial loss of fixation speed. 

Figure 2 Silver content and inst taneous silver freight upon processing of 1of D7 film...

To comply with existing and future legislation with respect to silver content in processor rinsing water, the approach developed by Agfa is threefold. 

First, we want to offer G335SF in combination with STRUCTURIX SILVERFIX as a viable solution to customers who want to upgrade their existing equipment (installed base processors) in order to decrease the silver content of their rinsing water. 

Thirdly, a NDT-S type cascade processor will be offered. By implementing a fixing cascade in the processor, large decreases of silver content in the rinsing water are possible, even for large customers. 

Saccharic acid. Use the filtrate A) from the above oxidation of lactose or, alternatively, employ the product obtained by evaporating 10 g. of glucose with 100 ml. of nitric acid, sp. gr. 1 15, until a syrupy residue remains and then dissolving in 30 ml. of water. Exactly neutralise at the boiling point with a concentrated solution of potassium carbonate, acidify with acetic acid, and concentrate again to a thick syrup. Upon the addition of 50 per cent, acetic acid, acid potassium saccharate sepa rates out. Filter at the pump and recrystaUise from a small quantity of hot water to remove the attendant oxahc acid. It is necessary to isolate the saccharic acid as the acid potassium salt since the acid is very soluble in water. The purity may be confirmed by conversion into the silver salt (Section 111,103) and determination of the silver content by ignition. 

In the dispersed-phase amalgam an additional phase of an eutectic of the Ag—Cu system and a reaction ring (2one) of Cu Sn [12019-69-1] around the residual silver alloy particles has been detected. If 10% gold is added to conventional alloys at the expense of the silver content, non-y2 amalgams are... 

Alloys based on Ag—Pd have been used for a number of years and are available from most gold alloy manufacturers (148). The palladium content is 22—50 wt % silver content is from 35 to 66 wt %. Minor amounts of Zn, In, or Sn are often present to increase fluidity. Both In and Sn form intermetaUic compounds with both Pd and Ag and, therefore, some of the commercial alloys are susceptible to age hardening (149). These alloys are somewhat difficult to fabricate and require meticulous processing. They may also produce a greenish discoloration when they are fused with porcelain veneers. Nevertheless, clinical experience generally has been satisfactory, and cost is the primary criterion for use. 

Silber gare,/. silver refining, -gefaait, m. silver content, -gewinnung, /. extraction of silver, -glanz, m. silvery luster silver glance, argentite. 

Heubner, U. and Reinert, M., Effect of Small Silver Contents on the Characteristics of Lead and its Alloys , Pb80, Seventh International Lead Conference, Lead Development Association, London... 

Tests have indicated failure to form PbO rapid deterioration, although at 100 Am it slows down after several weeks. Increasing silver content results in some improvement ". Anode passivated in 0-163 ohm m water continues to operate whilst PbO, is undamaged "". ... 

Silver content (by chemical analysis) of photographic emulsions on him base (mg Ag/sq cm)... 

Combustion and explosion hazards of the powdered alloy used in batteries were studied. Increase in silver content leads to higher values of the ignition temperature and COI [1,2],... 

Season of collection (Fowler and Oregioni 1976 Sanders etal. 1991) and latitude (Anderlini 1974) also influenced silver accumulations. Seasonal variations in silver concentrations of Baltic clams (Macoma balthica) were associated with seasonal variations in soft tissue weight and frequently reflected the silver content in the sediments (Cain and Luoma 1990). Oysters from the Gulf of Mexico vary considerably in whole-body concentrations of silver and other trace metals. Variables that modify silver concentrations in oyster tissues include the age, size, sex, reproductive stage, general health, and metabolism of the animal water temperature, salinity, dissolved oxygen,... 

Finally, alternatives exist to the use of silver in various materials and processes. These include substitution of aluminum and rhodium for silver in mirrors and other reflecting surfaces tantalum replacement of silver in surgical plates, pins, and sutures stainless steel as an alternative material to silver in the manufacture of table flatware and, in photography, film with reduced silver content (Reese 1991). 

Silver content of anolyte circuit (AgN03) makeup rate —Waste feed cutoff tied to current flow —Temperature of anolyte feed tank (main concern is precipitation of by-products)... 

Fig. 4.2 Typical variations in ionic conductivity with composition. In all cases, variations in alkali or silver content are very low compared to the observed variation in log a (a) influence of the network modifier (LijS) (b) influence of a doping salt (c) mixed alkali effect (d) mixed anion effect. References for data are indicated in Souquet and Perera (1990).

Silver is somewhat rare and is considered a commercially precious metal with many uses. Pure silver is too soft and usually too expensive for many commercial uses, and thus it is alloyed with other metals, usually copper, making it not only stronger but also less expensive. The purity of silver is expressed in the term fitness, which describes the amount of silver in the item. Fitness is just a multiple of 10 times the silver content in an item. For instance, sterling silver should be 93% (or at least 92.5%) pure silver and 7% copper or some other metal. The fitness rating for pure silver is 1000. Therefore, the rating for sterling silver is 930, and most sliver jewelry is rated at about 800. This is another way of saying that most silver jewelry is about 20% copper or other less valuable metal. 

Many processes are known for recovery of silver from its ores. These depend mostly on the nature of the mineral, its silver content, and recovery of other metals present in the ore. A few processes are briefly outlined below. 

Another method to control silver content in the active layer is to use active powders with different silver loadings. Even though this method introduces additional complexities since the intrinsic reactivities of these active powders may be different, a... 

About twelve years ago, the professor of natural history, Piller,4 who died here, gave me a little piece of ore from Deutsch-Pilsen in the Hont region, saying that it was argentiferous molybdenite and that I might determine the silver content. In some experiments that I made with i, I found, to be sure, that it... 

Th. Richter, said Weisbach. had already determined the silver content in two concordant blowpipe analyses as 73V2 per cent. My colleague Cl. Winkler then obtained as the mean of several experiments 75 per cent of silver and 18 of sulfur, hence a loss of 7 per cent. This loss, after long remaining inexplicable, finally led, in the course of further investigations, to the discovery of a new element similar in properties to arsenic or antimony, which Winkler, the discoverer, on February 1st named germanium (28). 

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