Caustic treatment molten

The lead contains residual calcium and magnesium that must be removed by chlorination or treatment with caustic and niter. The molten lead is pumped or laundered to the casting kettles in which it is again treated with caustic and niter prior to mol ding, After a final drossing, the refined lead is cast into 45-kg pigs or 1- and 2-t blocks. 

Other methods of cleaning iron and steel include immersion in molten sodium hydride and cathodic treatment in molten caustic soda. These methods may be hazardous to personnel, and should not be carried out by the uninitiated, or without professional supervision. 

Levels of many trace elements in Illinois No. 6 and Pittsburgh No. 8 coals were significantly reduced by treatments with molten caustic mixtures or aqueous alkali solutions, followed by washing with acid. Treating run-of-mine Illinois No. 6 coal with aqueous Na2C03 at elevated temperatures and pressures and washing the product coal subsequently with acid reduced Mn, Pb, and Zn concentrations by 75% or more, while levels of Cd and Ni were reduced by lesser amounts. In one of these samples, substantial reductions in levels of Ba, Cr, Rb, and Sr were also observed. Coals which were treated with molten NaOH/KOH mixtures at atmospheric pressure showed substantial reductions 1n concentrations of As, Cd, Hg, Pb, Rb, Se, Sr, and Zn. The amounts of several elements, such as Cr, Cu, and Ni, were elevated in some of the treated coals, but this can be attributed to corrosion of reactor components. 

Photochromic l,3-dichloro-6-phenoxy-7,12-phthaloylpyrene (V) was obtained by the interaction of the trichloro derivative with molten phenol containing caustic potassium hydroxide (Scheme 8). The treatment of 1,6,8-tichloro-2,3,-phthaloylpyrene with different substituted phenols yielded a number of phenoxy derivatives with different substituents on the phenyl group.59... 

Molten salt oxidation Combines chemical and thermal treatment. Wastes and oxygen are fed into a bath of molten caustic salt—usually sodium carbonate or a mixture of sodium and potassium carbonate. The wastes are oxidized, typically producing emissions of carbon dioxide, water, nitrogen, and oxygen ash and soot are retained in the melt. Salt can later be removed for disposal or for processing and recycling. 

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