Mining knowledge

Moh’s scale of hardness is as follows : '1.Talc 2.Gypsum    Scratched by finger  . 3.calcite 4.Fluorspar  Scratched by a knife" 5.Apatite ' 6.Orthoclasc  Sczirccly scratched by a knife. 7.Quartz ‘ ' 8.topaz. . . . 9.Corundum Not scratched by a knife. 10. Diamond ' It may be observed that : A finger nail will scratch upto about 2.5.. A pen knife will scratch upto 6.5  When testing the hardness of mineral window glass can be used as a substitute for apatite. ‘ , Protodyakonov strength number : Hardness of rock is expressed by Protodyakonov strength number in Russia. The number indicates the relative ease with which a rock can be broken, e.g. strong lignitcs and weak clay shalcs have Protodyakonov strength number as 15 to 2; strong colas and am hracitcs have strength number as 2; exceedingly strong quartzites and gabbro diorites have the number as 20-25, the highest number. Other rocks have the numbers inbetween.  Electrical and magnetic properties of m

What is mining ? “Mining is the process of excavating minerals of economics value from the earth’s crUSt for benefit of mankind”. Here we can assume that the earth’s crust, the outer surface of the earth, including the oceans, lakes and rivers, extends to depths of 30 to 50 km or so. For mining operations one should have a working knowledge of geology. The word Geology means science of the earth and deals with the nature and origin of the rocks that constitute the earth. A person interested in the extraction of minerals from the earth is, however, concerned with the thin surface of the rocks which make up the earth’s crust for a depth of a maximum of 5 km so that geology enables him to locate and to decide the sites most economic for mining or quarrying. In geology the terms mineral and rock have precise but different meanings. A mineral is a homogeneous and naturally occuring substance having definite physical properties and a composition that may be expressed by a chemical formula.