This is what soda ash is from: INDUSTRIAL MINERALS ASSOCIATION - NORTH AMERICA
What is Soda Ash?
Soda ash, also known as sodium carbonate (Na2CO3), is an alkali chemical refined from the mineral trona or naturally occurring sodium carbonate-bearing brines (both referred to as natural soda ash), the mineral nahcolite (referred to as natural sodium bicarbonate, from which soda ash can be produced), or manufactured from one of several chemical processes (referred to as synthetic soda ash).
A series of refining steps are required to produce soda ash from trona ore. First the raw ore from the mine is crushed and screened. The material is then fed to rotary calciners and heated. In this process, the trona decomposes to form crude soda ash, which is dissolved in water. The insoluble shales are separated from the solution by a combination of settling and filtration steps, and the resulting insoluble tailings are taken back into the mine as backfill. The soda ash solution is treated to remove organic materials yielding a high-purity saturated solution of sodium carbonate.
Next, the solution is fed to crystallizers where water is evaporated and sodium carbonate monohydrate crystals are formed. The industry-familiar term "mono-process" originates from this process step. The crystals are dewatered and washed using cyclones and centrifuges, and the solution is recycled to the evaporator units for further recovery of soda ash. The monohydrate crystals are fed to rotary kilns where they are dried to finished soda ash. Finally, product is screened and sent to storage silos awaiting rail and truck loadout.
Where is it used?
Soda ash has a number of diversified uses that touch our lives everyday. Glass manufacturing is the largest application for soda ash whether it is in the production of containers, fiberglass insulation, or flat glass for the housing, commercial building, and automotive industries. Soda ash also is used to clean the air and soften water. As environmental concerns grow, demand increases for soda ash used in the removal of sulfur dioxide and hydrochloric acid from stack gases. Chemical producers use soda ash as an intermediate to manufacture products that sweeten soft drinks (corn sweeteners), relieve physical discomfort (sodium bicarbonate) and improve foods and toiletries (phosphates). Household detergents and paper products are a few other common examples of readily identifiable products using soda ash.
Its pretty harmless in a dry state when its loaded into RR cars. Its laying all over the place out here along the tracks, from derailments and just from the cars getting beat around making the gates leak. They still do make a small amount of liquid caustic and ship it by railcar, but not as much as they did in the 90's.
Last edited by UPRR engineer on Tue Jul 25, 2006 12:56 pm, edited 1 time in total.