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When the hydraulic pressure is removed from the well, small grains of hydraulic fracturing proppants (either sand or aluminium oxide) hold the fractures open. Hydraulic fracturing began as an experiment in 1947, and the first commercially successful application followed in 1950.
Some of the first uses of asbestos insulation occurred in the latter half of the 1800s where hot-temperature pipes were a concern. Heat insulation containing asbestos was used for the first time in 1866. A few years later in 1870, the mineral was mixed with cement for boiler coverings. By 1874, asbestos insulation products reached commercial production and were sold on a mass scale. Bans on this type of insulation didnât occur until the 1970s.