NIOSHTIC-2 Publications Search
Physical properties and mechanical cutting characteristics of cobalt- rich manganese crusts.
Larson-DA; Tandanand-S; Boucher-ML; Olson-MS; Morrell-RJ
Minneapolis, MN: U.S. Department of the Interior, Bureau of Mines, RI 9128, 1987 Jan; :1-35
The Bureau of Mines conducted research to develop preliminary engineering data necessary if the cobalt-rich manganese crusts that occur in the exclusive economic zone of the Hawaiian archipelago are to be mined. The research was divided into the following sections: (1) physical, mineralogical, and chemical descriptions, (2) mechanical property testing, such as compressive strength, tensile strength, and a rippability index, and (3) mechanical cutting characteristics, including average and peak cutter forces, the specific energy, and cuttings size distribution. Section 1 utilized microscope, x-ray powder diffractometer, and electron microprobe analyses. Section 2 utilized standard mechanical property testing techniques. Section 3 utilized a converted planer mill with full- size coal cutters to fragment the crust and substrate samples. The manganese crust samples were mainly manganese and iron oxides and hydroxides with an average cobalt content of 1 pct and had a nucleus or substrate of rock or sediment. The significant results shown by the mechanical property and cutting tests are that the crust and all but two types of substrates (basalt and trachyte) are weak materials and easily cut with standard drag cutters. The crusts are generally comparable to medium-hard coal in strength and in their resistance to cutting.
Mining engineering; Cobalt; Manganese; Cutting; Crusts; Physical properties; Mechanical properties; Undersea mineral deposits; Ocean bottom; Exclusive Economic Zone; Hawaiian Archipelago
IH; Report of Investigations
NTIS Accession No.
Minneapolis, MN: U.S. Department of the Interior, Bureau of Mines, RI 9128
Page last reviewed: September 2, 2020
Content source: National Institute for Occupational Safety and Health Education and Information Division