River sands

Rhodium occurs native with other platinum metals in river sands of the Urals and in North and South America. It is also found with other platinum metals in the copper-nickel sulfide area of the Sudbury, Ontario region. Although the quantity occurring here is very small, the large tonnages of nickel processed make the recovery commercially feasible. The annual world production of rhodium is only 7 or 8 tons. 

Large deposits of monazite (found on the beaches of Travancore, India and in river sands in Brazil), ahanite (in the western United States), and bastnasite (in Southern California) will supply cerium, thorium, and the other rare-earth metals for many years to come. 

Ruthenium and osmium are generally found in the metallic state along with the other platinum metals and the coinage metals. The major source of the platinum metals are the nickel-copper sulfide ores found in South Africa and Sudbury (Canada), and in the river sands of the Urals in Russia. They are rare elements, ruthenium particularly so, their estimated abundances in the earth s crustal rocks being but O.OOOl (Ru) and 0.005 (Os) ppm. However, as in Group 7, there is a marked contrast between the abundances of the two heavier elements and that of the first. 

Franzinelli, E. and Potter, P. E. (1983). Petrology, chemistry, and texture of modem river sands, Amazon River system. /. Geol. 91, 23-39. 

The anaerobic dechlorination of hexachlorobenzene has been described in anaerobic mixed cultures supplemented with electron donors including lactate, ethanol, or glucose (Holliger et al. 1992) successive and partial dechlorination produced 1,2,4- and 1,3,5-trichlorobenzenes, while the 1,2,3-trichlorobenzene was further dechlorinated. The partial dechlorination of 1,2,3,4-tetra-, 1,2,3,5-tetra-, and pentachlorobenzene has been examined in a methanogenic mixed culture using lactate as electron donor (Middeldorp et al. 1997), and sterile Rhine River sand was needed to maintain dechlorination activity for unresolved reasons. 

Throughout the ages humans have used sand for many and the most varied uses. Some river sand, known as auriferous sand, contains native gold... 

Geldart (1970) showed a substantial distinction between bubble sizes in two dimensional and three dimensional beds. He used 128 pm river sand in a 30.8 cm round bed and a 68 1.27 cm rectangular cross section bed. The results, shown in Fig. 12, show that the bubbles in the three dimensional bed are larger. There were differences in the visible bubble flow rate at the same superficial velocity. Geldart ascribes the differences in bubble diameter to differences invisible bubble flow rate as well as to out-of-line coalescence in the three dimensional bed. 

Patrick, G. C. and Anthony, T., 1998, Creosote and Coal-Tar DNAPL Characterization in Fraser River Sands In Nonaqueous-Phase Liquids, Remediation of Chlorinated and Recalcitrant Compounds (edited by G. B. Wickramanayake and E. Hinchee), Battelle Press, Columbus, OH, pp. 149-154. 

Praseodymium is mainly found in monazite sands and bastnasite ores. The monazite sands contain all of the rare-earths and are found in river sand in India and Brazil as well as in Florida beach sand. A large deposit of bastnasite exists in California. 

Europium is the 13th most abundant of all the rare-earths and the 55th most abundant element on Earth. More europium exists on Earth than all the gold and silver deposits. Like many other rare-earths, europium is found in deposits of monazite, bastnasite, cerite, and allanite ores located in the river sands of India and Brazil and in the beach sand of Florida. It has proven difficult to separate europium from other rare-earths. Today, the ion-exchange... 

Gadohnium is the 40th most abundant element on Earth and the sixth most abundant of the rare-earths found in the Earths crust (6.4 ppm). Like many other rare-earths, gadolinium is found in monazite river sand in India and Brazil and the beach sand of Florida as well as in bastnasite ores in southern California. Similar to other rare-earths, gadolinium is recovered from its minerals by the ion-exchange process. It is also produced by nuclear fission in atomic reactors designed to produce electricity. 

Dysprosium is the 43rd most abundant element on Earth and ranks ninth in abundance of the rare-earths found in the Earth s crust. It is a metallic element that is usually found as an oxide (disprosia). Like most rare-earths, it is found in the minerals monazite and allanite, which are extracted from river sands of India, Africa, South America, and Australia and the beaches of Florida. It is also found in the mineral bastnasite in California. 

It is found in ores along with other rare-earths that were first found in the Ytterby quarry of Sweden. These ores are xenotime, euxenite, gadolinite, and monazite. Monazite river sand is... 

Potter, P.E. 1978. Petrology and chemistry of modern Big River sands. Journal of Geology, 86, 423-449. 

Assemble the setup shown in Fig. 43 (the experiment is performed by two students). Pour a small amount of moist river sand onto the bottom of a dry refractory test tube, seeing that the tube... 

After slaking, he directs to mix three parts of pit sand to one of lime, but if river sand or sea sand is used, then to mix two parts to one of lime, but to use with this a third part of burned brick pounded fine and sifted. 

Mavis and Wilsey (loc cit) recently retested Hazen s formula, and on the basis of extensive experiments on Iowa River sands give the following equations... 

River sand A Bubbling styrol PVC tube with inner diameter of 30mm... 

The effect of buffer materials is to soften shock waves. The safety wrapping technique for paper percussion cups which are commonly used to start sports events was tested by exposure to a weak shock wave. The small gap test (II) (Sec.5.2.3 in this book) was used. A propagated explosion test using a strong shock wave was also tried in sand (Sec.3.8.3). As a result of these tests, it was found that river sand was a practical materia] that could be used to soften shock waves. 

Injecting 0.5 PV of 2.5% Kern River oil-in-water emulsion into a sandpack made from Kern River sand reduced the permeability from 1624 to 397 md, a reduction of 76%. This is a significant result since injection of 0.5 pore volume of a steam-swept zone is economically viable should a field test be performed. An additional 0.5 PV of the emulsion was injected, lowering the permeability to 226 md. The stability of the block under steamflooding conditions was tested by injecting saturated steam at 150 C. After steam injection, the permeability was 406 md—still a 75% reduction in effective permeability (see Table VI). 

TABLE VI. Injection of 2.5% emulsion into Kern River sand... 

River sand, which is mixed with lime, and is made use of in building. 

Pure Naricum Iron, found in river sand. 

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