Accession Number : AD0772506

Title :   Study of High Powered Plasma for In Situ Hard Rock Disintegration.

Descriptive Note : Final technical rept. 1 Apr 72-21 Jul 73,

Corporate Author : HUMPHREYS CORP BOW N H TAFA DIV

Personal Author(s) : Poole,John W. ; Thorpe,Merle L.

Report Date : 21 JUL 1973

Pagination or Media Count : 83

Abstract : The report describes an investigation of hard rock cutting using a transferred arc plasma for melting narrow, deep cuts in hard rock at high speed and removing the intervening rock by thermal fracturing. The one year experimental program resulted in the development of a cutting system capable of operating horizontally and vertically at 250-500 kW, producing continuous cuts in granite and basalt at 2-1/2 to 12 inches per minute depending on cut depth which ranged from one to nineteen inches. Thermal melting efficiencies were in the range of 20-30 percent. (Modified author abstract)

Descriptors :   *Rock, *Arc melting, Plasma jets, Disintegration, Heat transfer, Tunneling, Electric arcs, Plasmas(Physics), Cutting

Subject Categories : MINING ENGINEERING
      CIVIL ENGINEERING

Distribution Statement : APPROVED FOR PUBLIC RELEASE

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