Leaching processing methods

Solvent extraction foUowing roasting and leaching is a promising processing method for dolomitic shale from Nevada (9). 

Whatever the mechanism and the method of operation, it is clear that the leaching process will be favored by increased surface per unit volume of sohds to be leached and by decreased radial distances that must be traversed within the solids, both of which are favored by decreased particle size. Fine solids, on the other hand, cause slow percolation rate, difficult solids separation, and possible poor quahty of sohd product. The basis for an optimum particle size is estabhshed by these characteristics. 

Dwyer et al. (43) have also reported that dealumination of Y zeolites by a steam/acid leaching process produces a more uniform composition than dealumination by EDTA. The later method caused a depletion of Al in the outermost surface layer, producing a compositional gradient in the zeolite crystals. The conclusions reached by J. Dwyer in his studies of aluminum-deficient zeolites using the FABMS method are summarized in Table IV. 

In mercury speciation studies, pressurized liquid extraction (PLE), microwave-assisted extraction (MAE), and supercritical fluid extraction (SEE) are employed [33]. In particular, methyl-mercury is extracted by the Westoo method [33,34], which consists in a leaching process with hydrochloric acid, the extraction of the metal chloride into benzene or toluene, the addition of ammonium hydroxide that converts the metal species to hydroxide and the saturation with sodium sulfate. Most of the HPLC methods reported in literature for the determination of organomercury compounds (mainly monomethyhnercury, monoethyhnercury, and monophenylmercury) are based on reversed... 

The eluant is usually 1 M N07 in the form of NH4NO3. The physical method for carrying out the extraction can involve (a) a fixed resin bed, (b) a resin-in-pulp technique where resin in baskets is passed through a stream of pulp or slurry from the leach process, or (c) a moving bed of resin. 

Hydrometallurgical treatment of lateritic ores, by the reduction roast/ammonia leach process is one of the methods used for the recovery of nickel from low grade lateritic ores. In a recent study Chander and his associates (19, 20) used such... 

Comparison of the results of analysis by FAAS of the solutions produced by each of these methods indicated that procedures 1 and 3 were preferable to the others with respect to precision and accuracy. Procedure 1 was less accurate for chromium than procedure 3. In addition, procedure 3, which employed microwave digestion, took considerably less time to complete. Method 4, the leaching process, produced acceptable results only for Fe, Mg, Zn, and Cu. 

The catalyst was prepared from 2 g of 40% Ni-Al alloy by the procedure for the T-4 catalyst each time before use. T-4 unpromoted catalyst T-4/Pt the catalyst platinized during leaching process with 0.05 g of chloroplatinic acid (0.0185 g Pt) T-4/Pt (Delepine-Horeau) T-4 Raney Ni platinized with 0.05 g of chloroplatinic acid by the method of Delepine and Horeau (Ref. 66). 

Burning herbs to ash is easy enough over a small propane stove, but there are a few problems. First there is the smoke and smell, sure to attract the attention of your neighbors and elicit moans and groans from other people of your household. Unless you have a good fume hood, this is definitely an outdoor activity. Secondly, there are some materials which refuse to get very white at all. There is a simple method we can use, called the leaching process, to obtain the salts in a purified form. 

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