Limestone transportation

Kosugi, S. A capsule pipeline system for limestone transportation. Proceedings of the 7th International Symposium on Freight Pipelines, Wollongong, Australia, Jul 6-8, 1992 Institution of Engineers Barton Act, Australia, 1992. 

Pneumatic Pipelines. Pneumatic pipe systems are used to move blood samples, medicine, and suppHes between buildings in hospital complexes cash and receipts in drive-up banks parts and materials in factories refuse from apartment complexes and grain, cement, and many other materials. Most of these are small diameter and usually short however, a 17-km, 1220-mm dia pneumatic pipeline has been used to transport rock in the former Soviet Union since 1981, and a 3.2-km, 1000-mm dia line has moved limestone from the mine to a cement plant in Japan since 1983 (22). 

Coal pipelines have been built in countries such as France (8.8 km), and Russia (61 km), and pipelines are also used for transporting limestone, copper concentrates, magnetite, and gHsonite in other parts of the world. The first coal pipeline, built in Ohio, led to freight rate reductions. The pipeline stopped operation after introduction of the unit train, used exclusively to transport coal from the mine to an electric power generation station. 

More CO2 can actually be absorbed chemically into the ocean than the above reaction sequence suggests. Terrestrial weathering of rocks containing carbonate, such as limestone, and subsequent aerial or riverine transport, means that the ocean is enriched in carbonate. Keeping and Kj constant implies, through eqns. (3) and (4), that enhancing the oceanic [COj ] leads to a greater level of... 

Chemical Reactivity - Reactivity with Water No reaction Reactivity with Common Materials Corrosive to most metals with the evolution of flammable and explosive hydrogen gas Stability During Transport Stable Neutralizing AgerUs for Acids and Caustics Flush with water and apply powdered limestone, slaked lime, soda ash, or sodium bicarbonate Polymerization Not pertinent Inhibitor of Polymerization Not pertinent. 

James, J. G. and Broad, B. A. Transport and Road Research Laboratory, TRRL Supplementary Report 635 (1980) Conveyance of coarse particle solids by hydraulic pipeline Trials with limestone aggregates in 102, 156 and 207 mm diameter pipes. 

The transport of heat a fine example for this factor may be cited thermal decomposition of limestone endothermically to lime. The heterogeneous reaction is chemically shown as ... 

An incompletely reacted and sectioned sample of limestone would appear as shown in Figure 3.27. For the reaction to sustain it is highly required that flow of heat occurs from outside the limestone sample particle to the reaction interface, which represents the shrinking core of limestone. This heat transport by conduction in the pores and solid body of the lime can affect the rate of reaction. 

Figure 3.27 Endothermic thermal decomposition of limestone to lime, showing the need for transport of heat.

In the end, both approaches require the calcination of limestone to lime. The energy penalty in this process is about 4.5-5 GJ/ton of C02, which amounts to a 30-40% energy penalty of a transportation sector that uses air extraction for managing its own C02 emissions. This is comparable to the energy penalty incurred in the conversion of fossil fuels into hydrogen as a transportation fuel (Zeman and Lackner, 2004). 

Let us consider a difficult example of sampling of mined materials (sand, dolomite, and limestone) used for the manufacture of glass. The materials are delivered in railroad cars each may contain up to 2 tons of material and are susceptible to vertical separation on the basis of size and density of particles because of vibrations during transportation [8]. To obtain a representative sample, sampling is done with a hollow... 

Sulfur Emissicms Sulfur present in a fuel is released as SO2, a known contributor to acid rain deposition. By adding limestone or dolomite to a fluidized bed, much of this can be captured as calcium sulfate, a dry nonhazardous solid. As limestone usually contains over 40 percent calcium, compared to only 20 percent in dolomite, it is the preferred sorbent, resulting in lower transportation costs for the raw mineral and the resulting ash product. Moreover, the high magnesium content of the dolomite makes the ash unsuitable for some building applications and so reduces its potential for utilization. Whatever sorbent is selected, for economic reasons it is usually from a source local to the FBC plant. If more than one sorbent is available, plant trials are needed to determine the one most suitable, as results from laboratory-scale reactivity assessments are unreliable. 

---