Weldon mud

Weldonschlamm, m. Weldon mud. welk, a. withered, faded flaccid languid. Welkboden, m. (Brewing) withering floor, welken, v.i. wither, wilt, fade, decay. — v.t. wither, wilt, dry. 

The process was complicated by the formation of calcium manganite, CaMn206, known as Weldon mud. Invented by W. Weldon in 1866 and developed at St. Helens from 1868 to 1870. Operated in competition with the Deacon process until both were overtaken by the electrolytic process for making chlorine from brine. Weldon mud has been used as a catalyst for oxidizing the hydrogen sulfide in coal gas to elemental sulfur. 

The precipitated slurry, containing CaO. 2MnOa, called the Weldon mud was then used instead of black oxide of manganese fer the oxidation of hydrochloric acid. This reaction which was carried out in sandstone containers with steam fed into the reaction mixture proceeded according to the equation ... 

Manganese dioxide (Mn02), or the so-called Weldon mud which is a manganous-manganic oxide (xylene blue V, page 303). 

The Weldon mud Manganschlamm ) is calculated as MnO-j, i.e., one uses the equivalent of exactly 100 grams of manganese dioxide. Weldon mud, a by-product of saccharin manufacture, has the approximate composition, MnsOi. 

Claus felt that the cyclic process could be simplified if the hydrogen sulfide were converted to sulfur by an iron catalyst in a kiln. It was later found that dried Weldon process mud or bauxite would operate as a catalyst at a lower temperature than ferric oxide. This not only extended the life of the kiln but also increased sulfur yield. Problems with blocked beds were overcome as technology evolved and proper reactors containing solid catalyst particles were developed. Thus, the modem Claus sulfur recovery process originated from the statutory obligation to remove sulfur from town gas in Victorian gas works. 

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