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
Waste-to-energy plant incinerate 80 to 90 percent of waste. Sometimes, the residue ash is clean enough to be used for some purposes such as raw materials for use in manufacturing cinder blocks or for road construction. In addition, the metals that may be burned are collected from the bottom of the furnace and sold to foundries. Some waste-to-energy plants convert salt water to potable fresh water as a by-product of cooling processes. The typical plant with capacity of 400GWh energy production annually costs about 440 million dollars to build. Waste-to-energy plants may have a significant cost advantage over traditional power options, as