Another common industrial acid is sulphuric acid – indeed it is probably one of the most common industrial chemicals shipped by rail. Uses of sulphuric acid are almost endless, but include chemical digestion of wood fibers for paper making and the production processes of fertilizers and numerous other chemicals including hydrochloric acid (as seen in last week’s Freight Car Friday).
Sulphuric acid is often produced in massive quantities as a byproduct of the smelting and refining of metal ores. Based on the (lack of) compression in the truck springs this and the neighbouring white PVCX acid tank car are heading north empty, for interchange to the Ontario Northland for furtherance to the copper/zinc smelter at Noranda, QC.
Hydrochloric acid is a commonly produced industrial chemical that has applications in many chemical and industrial processes including steel making. In steel mills it is used to remove rust, scale and other surface impurities from finished steel.
While the car above was not photographed on the Algoma Central, it is representative of a common type of car in hydrochloric acid service. (Note that the Athearn 20,900 gal. RTC acid tank car is pretty much bang on for this prototype.) I did see a couple of similar SHPX cars at Hawk Junction, but didn’t get a good photo; I could also see some similar tank cars from a distance in Steelton yard from the Canyon Tour Train.
A related byproduct of using hydrochloric acid in the steelmaking process is the production of ferrous chloride as a waste product. This corrosive chemical has uses in water treatment systems, and a CN conductor friend of mine recently mentioned that he occasionally delivers a tank car of ferrous chloride from Sault Ste. Marie to the water treatment plant in downtown Toronto. Ferrous chloride (and related compounds like ferric chloride) is also shipped in tank cars of a similar size and design to hydrochloric acid.