Boart Longyear samples for the proposed Golden Gate Bridge in San Francisco. In spite of the financial crisis, the 1930s saw improvements in diamond drilling technology, including the use of industrial-quality diamonds mined in Africa that were called “boarts.” In 1936, South Africa’s Anglo American Corporation formed Boart Products South Africa (Pty) Limited, which was later named Boart International. The new company developed the first mechanically-set diamond core bits, which were less expensive than the hand-set core bits that used more expensive Brazilian diamonds (carbonados). Longyear’s business gradually improved in the 1940s in response to expanding worldwide mineral exploration. In 1949, the
Green waste landfills. Green waste can be used to improve the quality and sustainability of industrially manufactured topsoils and the sanitariness and efficiency of sewage disposal. Green waste is an integral part of many manufactured topsoils, as it provides both nutrients for growing plants and increases the volume of manufactured topsoils. Its woody components do not decompose quickly, so they provide the bulk that is necessary for supplementary topsoils. Mixing industrial wastes such as fly ash or coal dust with green waste to create artificial topsoil not only facilitates the repurposing of industrial debris and keeps it out of landfills, but it