Sulfur coke removal methods

The ore is crushed and ground and separated into various mineral concentrates by flotation. The complex lead-zinc ores have played an important role in the development of the flotation technique. A lead concentrate with perhaps 77% Pb is roasted to oxide, in general on a sinter band, a process in which sulfur is removed as sulfur dioxide. Limestone is added for slag formation and the sinter is reduced by coke in a shaft furnace. An alternative method is to use a rotating converter furnace, from which the sulfur dioxide can be used for sulfuric acid production. This is good for the environment and good for the economics of the process. 

Sulfur removal, as currently practiced in the petroleum industry, can be achieved using three options. The first option involves the use of thermal methods such as the various cracking techniques that concentrate the majority of the sulfur into the nonvolatile products, i.e., coke. Such processes are located in the conversion section of a refinery (Figure 4-1). The remainder of the sulfur may occur in the... 

From the sulfuric acid solution, thorium may also be obtained by precipitation with sodium fluosilicate, sodium hypo-phosphate,1 or sodium pyrophosphate.2 An ingenious method for removing the phosphorus has been proposed by Basker-ville3 and used on a large scale. It consists in heating in an electric furnace a mixture of monazite, coke, lime, and feldspar. The phosphorus is distilled out and the mass allowed to cool. When extracted with water, acetylene is evolved from the calcium carbide formed during the heating, and the remainder crumbles to a fine powder. This is dissolved in hydrochloric acid, and the cerium earths removed. 

The weight percent of sulfur on the catalysts was obtained via the high-temperature-combustion Dietert technique, ASTM method D1552. The sulfur analysis was based on the weight of the catalyst after all carbon had been removed, i.e., the weight percent reported is not masked by any residual wax or coke on the spent catalyst. 

Phenol is obtained by several methods. The middle oil (180-250 C) of pit coal tar is fractionally distilled, naphthalene is removed by cooling, and the alkali-soluble phenol is obtained by dissolving in caustic soda and then acidifying. Creosote is obtained from the heavy oil, which boils at 250-300°C, or from the wash water of coke production. o-Cresol is separated by multiple rectification, whereas p- and m-cresol can only be separated by chemical means. m-Cresol, unlike p-cresol, can be sulfonated at 130°C with dilute sulfuric acid. 

M Sabott, F. K.,. . Methods of Removing Sulfur from Petroleum Coke, Quar-... 

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