MT20 : MINING METHODS - OPENCAST WORKING

Mining Methods - Opencast Working

UNIT - 1

Classification of Surface Mining methods, Factors affecting choice of opencast mining methods; Advantages and disadvantages of opencast mining.

Stripping Ratio: Maximum allowable stripping ratio, Overall stripping ratio, Break even stripping ratio.

Benches parameters: Height, width, angle of slope, toe, crest, statutory provisions regarding height, width, angle of slope etc.

UNIT - 2

Unit operations involved, site preparation, Box cut, Entry system in opencast mines.

Opencast mine layout, factor determining choices of layout, overburden excavation, Disposal of overburden, overcasting etc.

Sample layouts for Lime Stone, Copper, Coal, Iron ore deposits, method of work, machines required, manpower, OMS etc.

UNIT - 3

Classification of Excavating equipment, selection, choices of opencast mining machinery.

Excavators shovel, Rope shovel, hydraulic shovel, application, advantages, disadvantages.

Comparison Rope shovel and hydraulic shovel, operating parameter, output of a shovel.

Various attachments to shovel. Back hoe, operating  parameter, application.

Dragline, operating parameters, applicability, working, advantages, disadvantages, comparison with shovel.

Bucket wheel and Bucket chain excavators. Application, advantages & disadvantages, operation, working methods by Bucket wheel excavator, terrace cut, Dropping cut etc.

Rippers. Scrappers, bulldozer etc.

Surface miner its application, working in pit crushing system.

Precautionary measures while use of HEMM.

UNIT - 4

Explosives used in opencast mine, ANFO, slurry explosive, emulsion explosives, Heavy ANFO explosive, LOX, their properties, composition etc. Boosters.

Initiation system, non-electric initiation system, Raydets, Nonel, Shock Tubes, electronic detonators, etc.

Bulk explosive system, site mixed slurry, site mixed Emulsion, Bulk-loading system, Advantages.

ANFO precautions while mixing, handling and use, Conditions for using bulk explosives.

UNIT - 5

Bench blasting terminology, Blast hole geometry, hole depth, burden, spacing, sub grade drilling, bottom change, column charge, stemming height.. Factors to be considered while blast designing.

Simple numerical on blast design for the bench of surfaces mine.

Single and multiple rows blasting their comparison, Sequence of blasting in single & multiple row.

Precautions while charging and firing of holes in deep hole blasting, deck charging, muffled blasting, control blasting techniques, secondary blasting/ breaking in opencast mines.

Transport of Explosives in bulk, precautions while drilling and blasting of deep holes.

UNIT - 6

Environmental aspects of opencast mining Fly rock, ground vibration, air blast their causes & prevention.

Noise pollution, water pollution, Degradation of land, land reclamation.

Salient features of environment protection Act, EMP and Environment impact assessment.

Slope stability: Causes of un-stability, forms of failure preventive measures.