Disperse copper deposits

The Effect of Temperature on Electrodeposition of Disperse Copper Deposits... 

Nikolic ND, Pavlovic LjJ, Pavlovic MG, Popov KI (2007) Effect of temperature on electrodeposition of disperse copper deposits. J Serb Chem Soc 72 1369-1381... 

Lovering, T. S., Huff, L. C., and Almond, H. (1950). Dispersion of copper from the San Manuel copper deposit, Pinal County, Arizona. Econ. Geol. 45, 493—514. 

Surveys for dispersion patterns of sulphide anions and compounds determined as acid-released HjS in soil have been carried out over 30 mineral deposits in China, including skams, porphyry copper deposits and porphyritic iron deposits (sulphur contents higher at the margin of the ore body), altered-brecciated gold deposits and lead-zinc deposits in volcanic breccia. Three successful case histories are summarised here. Of the remainder, only four failed to yield anomalies over mineralisation. 

SEM observation(Fig2) of the copper deposit also shows that the copper is not uniformly distributed but dispersedly located. This again indicates that copper grows through the crack of TiN layer. Fig 3 shows the TiN composition profile by AES near the crack area and Fig 4 is the profile of the copper deposit. These two figures again confirm that the copper deposit is not due to displacement reaction between TiN and Cu2 ... 

Because of its almost universal association with porphyry copper deposits and its mobility characteristics. Mo has been used extensively as a pathfinder element for geochemical prospecting for porphyry copper deposits (Rose, Hawkes, and Webb, 1979). Dispersion of Mo in mineralized areas has been shown to occur by both hydromorphic (Bradshaw, 1974) and mechanical (Hansuld, 1966) processes. 

Cross section of copper deposits obtained with deposition pulses of 4, 7, 10, and 20 ms is shown in Fig. 4.24. From Fig. 4.24, it can be seen that the interior of these structures was very porous and consisted of disperse particles surrounded by irregular chaimels for which the origin is of evolved hydrogen [44]. Also, it is necessary to note that dendritic character of these particles decreased with the prolonging duration of deposition pulse. As already mentioned, the porous interior of these deposits is very important for electrocatalytic purposes because the pores facilitate the transport of electroactive species through the interior of the structures, what is very desirable... 

Shown in Fig. 8 is a typical copper-tin foam stmcture prepared in an electrolyte of 1.5 M sulfuric acid containing 0.24 M copper sulfate and 0.20 M tin sulfate. The electro-deposit is characterized by typical foam stmcture like copper and tin. Moreover, the foam wall is highly-porous and full of numerous small grains. Pores of less than a few microns in foam wall are possibly caused by the hydrogen gas evolution on newly-developed copper-tin deposits, similar to the case of copper deposition. The atomic ratio of copper to tin of the deposit was estimated to be 1.18 using energy-dispersive X-ray spectroscopy and the X-ray diffraction analysis showed the deposit was ri -CueSus, a low-temperature variation of CueSns."... 

An orange-brown ring about 50 pm thick occurred all around the aluminum/copper interface. It was located on the aluminum material at a distance of about 150 pm from the interface. The ring was analyzed by energy-dispersive spectroscopy as being copper and is attributed to the deposition of copper coming from the dissolution of the aluminum/copper interface. This copper deposition will not be analyzed in the present work. 

Thin films of photochromic glass containing silver haUde have been produced by simultaneous vacuum deposition of siUcon monoxide, lead siUcate, aluminum chloride, copper (I) chloride, and silver haUdes (9). Again, heat treatment (120°C for several hours) after vacuum deposition results in the formation of photochromic silver haUde crystaUites. Photochemical darkening and thermal fade rates are much slower than those of the standard dispersed systems. 

Internal surfaces were covered with a tan deposit layer up to 0.033 in. (0.084 cm) thick. The deposits were analyzed by energy-dispersive spectroscopy and were found to contain 24% calcium, 17% silicon, 16% zinc, 11% phosphorus, 7% magnesium, 2% each sodium, iron, and sulfur, 1% manganese, and 18% carbonate by weight. The porous corrosion product shown in Fig. 13.11B contained 93% copper, 3% zinc, 3% tin, and 1% iron. Traces of sulfur and aluminum were also found. Near external surfaces, up to 27% of the corrosion product was sulfur. 

Removal of deposits and corrosion products from internal surfaces revealed irregular metal loss. Additionally, surfaces in wasted areas showed patches of elemental copper (later confirmed by energy-dispersive spectroscopy) (Fig. 13.12). These denickelified areas were confined to regions showing metal loss. Microscopic analysis confirmed that dealloying, not just redeposition of copper onto the cupronickel from the acid bath used during deposit removal, had occurred. 

Conformance of dry film to the copper surface is a concern, particularly with stiff films. One way to improve conformance is to coat a low viscosity photopolymer liquid direcdy on the substrate. Several coating techniques are available to deposit photoresists directly onto metal substrates. These techniques involve dissolving/dispersing the ingredients in a solvent, coating the solution on the substrate and removing the solvent. Some of the material is lost during the... 

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