Section 61.51 - DefinitionsTerms used in this subpart are defined in the act, in subpart A of this part, or in this section as follows:
(a)Mercury means the element mercury, excluding any associated elements, and includes mercury in particulates, vapors, aerosols, and compounds.(b)Mercury ore means a mineral mined specifically for its mercury content.(c)Mercury ore processing facility means a facility processing mercury ore to obtain mercury.(d)Condenser stack gases mean the gaseous effluent evolved from the stack of processes utilizing heat to extract mercury metal from mercury ore.(e)Mercury chlor-alkali cell means a device which is basically composed of an electrolyzer section and a denuder (decomposer) section and utilizes mercury to produce chlorine gas, hydrogen gas, and alkali metal hydroxide.(f)Mercury chlor-alkali electrolyzer means an electrolytic device which is part of a mercury chlor-alkali cell and utilizes a flowing mercury cathode to produce chlorine gas and alkali metal amalgam.(g)Denuder means a horizontal or vertical container which is part of a mercury chlor-alkali cell and in which water and alkali metal amalgam are converted to alkali metal hydroxide, mercury, and hydrogen gas in a short-circuited, electrolytic reaction.(h)Hydrogen gas stream means a hydrogen stream formed in the chlor-alkali cell denuder.(i)End box means a container(s) located on one or both ends of a mercury chlor-alkali electrolyzer which serves as a connection between the electrolyzer and denuder for rich and stripped amalgam.(j)End box ventilation system means a ventilation system which collects mercury emissions from the end-boxes, the mercury pump sumps, and their water collection systems.(k)Cell room means a structure(s) housing one or more mercury electrolytic chlor-alkali cells.(l)Sludge means sludge produced by a treatment plant that processes municipal or industrial waste waters.(m)Sludge dryer means a device used to reduce the moisture content of sludge by heating to temperatures above 65 °C (ca. 150 °F) directly with combustion gases.38 FR 8826, Apr. 6, 1973, as amended at 40 FR 48302, Oct. 14, 1975