Natural resources are the foundation for our lives and lifestyles.
What would our lives be like without mining? Imagine a world without transportation such as jet planes or railroads, without communications such as cell phones or radar, without decorative items such as art or jewelry, without buildings such as skyscrapers or parking garages, without defense systems items such as missiles or submarines, without medical care items such as X-rays or surgical tools. We wouldn’t have any of these things without mining and minerals.
The term diatomite is applied both geologically and commercially to the nearly pure sedimentary accumulation of diatom frustules—the microscopic skeletons of unicellular aquatic algae belonging to the class of golden brown algae, Bacillariophyceae. The sediments are fine-grained, highly siliceous, and consist primarily of amorphous opaline silica with only minor amounts of organic residue, secondary minerals, and co-deposited nondiatomaceous or crystalline clastic debris. Synonyms in current usage include diatomaceous earth and kieselghur. More antiquated and obsolete terminology includes tripoli powder, tripolite, and infusorial earth.
Rock Classification: sedimentary
Throughout most of the world, the lower cost of and higher recovery from open-pit quarrying relative to underground mining encourages operators to use surface mining methods. Where the diatomite sequence is thick, benches from 1.5 to 15 m in height are developed. Benching not only facilitates the removal of ore and waste but also permits immediate access to many ore layers and provides the opportunity to blend layers with differing characteristics. Notable exceptions are underground mines in Europe, South America, and Asia, and the dredging operation at Lake Myvatn, Iceland.
Prior to mining, the ore strata are carefully identified in the quarry faces through sampling and evaluation programs that determine and confirm the suitability of each individual stratum. The ore-grade strata can then be rated by quality and carefully segregated from the lower quality waste units using mechanized equipment. Because diatomite is a soft, easily broken sediment, ores are typically dozer ripped or broken from the face by power shovel. Blasting of the ores is neither needed nor possible because of the inherent softness of commercial quality diatomite, its porosity, and its absorptive nature. The broken material is loaded by front-end loader or belt loader into haul trucks for transport to either the crude storage area or the waste piles.
Typically, the moisture content of unprocessed ore ranges from 30% to 60%. Where the climate is favorable for solar drying, significant cost savings can be achieved by reducing moisture\ before milling. Crude grades may be blended or used separately depending on the final application.