DIATOMITEDiatomite is a sedimentary rock, that is white and yellowish incolor.
It is composed of fossilized skeletons of one-celled algae-likeplants called diatoms. It is accumulated in marine areas. TheHoneycomb sillia structure is useful because of its high absorptivecapacity and surface area. It is also very chemically stable.
Itsprincipal use is filtration. This substance of diatomite is extracted from many countriesaround the world. Out of 30 world countries the largest suppliers arethe United States, China, Denmark, and Japan. China supplies about350 thousand metric tons, Denmark extracts 375 thousand metrictons, and Japan, 190 thousand metric tons.
About 725 thousandmetric tons of diatomite are extracted from the US Worldwide about2,150 thousand metric tons are removed from the earth. This product consists of approximately 90 percent silica, and theremainder consists of compounds such as aluminum and iron oxides. The material is extracted by a dredging barge cuts sediment withrotating knives, mixes it with water and pumps it along a suspendedpipeline to the shore. Because diatomite is made from a skeletalstructure of diatoms, it isn’t made of chemicals that need to beextracted. It is highly unreactive to other chemicals.
It also has alow thermal conductivity rate and a high fusion point. Most diatomite mines are open pit mines because the depositsare usually at or near the surface. Open pit mines are especially hardon the environment because they are very large holes in the ground. Diatomite is also mined when geologic uplifting brings these depositsabove sea level. The diatomite is easily mined this way, however,being in marine areas, pollution in the water is a big concern.
Through the use of many mining machines, the waters can be easilypolluted. The method of dredging to cut away at the sediment doesnot seem like it would be as environmentally friendly as well. Asidefrom the mining having impact on the actual land, diatomite mininghas impacts on birds in surrounding areas. Many birds show atendency to avoid dredging areas.
Besides factors of noise andpollution and general unpleasantness of machines, birds also rely onanimals in shallow water for food where dredging has occurred. Currently there are no recycling methods for diatomite. Theeventual replacement of diatomite filters with membrane types maybe speeded by legislation regarding waste disposal, which would makethe option of dumping diatomite cake in landfill sites more expensiveor even prohibited. One environmental specification of color is put ondiatomite, because it is a calcine product. It has to be of a lightwhitish color or it is not available to be mined. This helpsenvironmentally because the color determines a standard for whatcompanies can and cannot mine.
I think one way for lessening the impact on the environment,would be to work harder at developing recycling methods fordiatomite cake. If recycling could be put into use not as muchdiatomite would need to be mined. To excavate diatomite, differentcombinations of rippers, dozers, scrapers, front-end loaders, powershovels, and dump trucks are used. Underground mining is not toouncommon outside the United States. Usually, room-and-pillarmethods are used, often with equipment similar to that used in openpits; in the smallest mines, hand tools are used.
Dredging is used torecover diatomaceous mud from the bottom of lakes. Since all thesemethods are used in excavation, I think the best idea would be tochoose the method with the least impact environmentally. Sixty four percent of the diatomite mined is used in filtration. Fourteen percent is used for absorbents, and twelve percent used infillers.
While two percent used for insulation, and eight percent usedin other ways. Diatomite is principally used in filtration of variousalcoholic beverages, sugar, oil, organic and inorganic chemicals, andwater. Many materials can be substituted for diatomite. Expandedperlite and silica sand compete for filtration purposes. Other filtrationtechnologies use ceramic, polymeric, or carbon membrane.
Alternatefiller materials include talc, ground silica sand, ground mica, clay,perlite, vermiculite, and ground limestone. For thermal insulationmaterials such as various clays and special brick, mineral wool,expanded perlite, and exfoliated vermiculite can be used. Conservation would mostly be attained through finding ways torecycle or more efficiently using the cake, or using substitutes for thematerial. Diatomite is an excellent filtering material for many things. Most commonly used in beverages, fruit juices, soft drinks, beer, andwine.
It is used in chemicals like sodium hydroxide, sulfuric acid, andgold salts. Filtration of cooking oils, vegetable and animal, andsugars, cane, beet, and corn,
