on April 14, 2022

What is long hole stoping?

Long hole stoping as the name suggests uses holes drilled by a production drill to a predetermined pattern as designed by a mining engineer. Long hole stoping is a highly selective and productive method of mining and can cater for varying ore thicknesses and dips (0 – 90 degree).

What is long hole open stoping?

Longhole stoping is a very popular method in underground mining for blasting a sequence of stopes in metalliferous mines. The holes are drilled according to a predetermined pattern designed by a mining engineer. This method is one of the most productive ones and covers a variety of ore thicknesses and dips (0 – 90⁰).

What is longitudinal stoping?

Longitudinal longhole retreat is a branch of the generic mining method known as sublevel stoping. For longitudinal retreat the long axis of the stope is along (or parallel) to the strike of the orebody. It may also be referred to as bench stoping or sublevel benching.

What is long hole mining?

Long Hole Drilling means, in its simplicity, drilling deeper holes into the ore in underground mining. This is also known as production drilling, and the typical hole depth varies mostly from 10 meters all the way up to 40 meters in extreme cases.

What is open stoping?

Stoping is practiced in underground mineral mining when the surrounding rock is strong enough to permit the drilling, blasting, and removal of ore without caving. In mines where the rock requires no artificial support, the operation is known as open stoping.

What is purpose of stope surveying?

When mines employ contractors a rapid method of surveying stopes is required so that the pay office can finalise payments at the end of a specific period. Such surveys are also necessary for geological planning purposes and to comply with regulations on keeping mine plans up to date.

What is the difference between block caving and sublevel caving?

Sub-level caving also allows for a slightly more selective extraction of the orebody than is attainable through block or panel caving. Production rates achieved in sub-level caving operations are typically lower than for block caves but higher than for stoping methods.” Caving is a non-selective, bulk mining method.

What is cave mining?

In general, cave mining refers to all underground mining techniques in which the orebody is ‘undercut’ or drilled beneath the surface and is recovered as it falls. The removal of the ore causes a large gap or ‘cave’ where the orebody previously resided.

Is block caving safe?

Hazards and Side Effects

Block caving creates large subsidence features on the surface, such as sinkholes. As a result of removing large continuous masses of rock, the overlying ground surface inevitably collapses to fill the void. Water contamination is a more serious concern.

What is sublevel caving?

Sublevel caving (SLC) is a mass mining method based upon the utilisation of gravity flow of blasted ore and caved waste rock [1]. The method functions on the principle that ore is fragmented by blasting, while the overlying host rock fractures and caves under the action of mine-induced stresses and gravity [2].

What is sublevel stoping?

Sublevel stoping is a mining method in which ore is blasted from different levels of elevation but is removed from one level at the bottom of the mine. Before mining begins, an ore pass is usually drilled from a lower to a higher elevation.

What are 4 types of mining?

There are four main mining methods: underground, open surface (pit), placer, and in-situ mining. Underground mines are more expensive and are often used to reach deeper deposits.

What is a longwall move?

longwall mining Mining. a mining method in which very long rectangular blocks of coal are defined during the development stage of the mine and then extracted in a single continuous operation by an automated cutting head moving parallel to the coal face.

What is Pillaring and retreat mining?

Retreat mining is the removal of pillars in the underground mining technique known as room and pillar mining. In the first phase of room and pillar mining, tunnels are advanced into the coal or ore body in a rectangular pattern resembling city streets.

What is tailgate mining?

Layout. Gate roads are driven to the back of each panel before longwall mining begins. The gate road along one side of the block is called the maingate or headgate; the road on the other side is called the tailgate.

What is bord and pillar mining method?

A system of mining in which the distinguishing feature is the winning of less than 50% coal on the first working. It is more an extension of the development work than mining. The second working is similar in principle to top slicing.

What is Panel mining?

In coal mining: Ground control and roof support. From the submains, panel entries take off to subdivide further a block of coal into panels for orderly coal extraction.

What is panel system in mining?

It is upon this system that all large modern mines in Illinois are projected. The term panel system originally implied the isolation of a group of rooms, called a panel, from other such groups or panels, by a surrounding pillar of coal pierced on one side only by the room en- tries.

What is Depillaring operation?

DEPILLARING It is the process of extraction of coal from pillars . It is also called pillar cutting or broken working.

How many types of Depillaring are there?

Introduction to Depillaring 2. Preparatory Arrangement before Depillaring 3. Depillaring By Caving (Method) 4. Depillaring of Contiguous Seams 5.

What is blasting gallery method?

Blasting Gallery (BG) method is suitable for extraction of virgin thick seams as well as developed pillars in thick seams in single lift. The method was very successful resulting in 85% of extraction with high productivity. But, this method experienced strata control problems during final extraction.

Which type of drilling pattern is followed in BG method?

In BG Method, drilling is done by crawler mounted electro-hydraulic jumbo drill which can drill at any angle in the vertical plane, as the method envisages drilling of holes in Fan Pattern. The length of hole depends on its position and seam thickness. The jumbo drill can drill upto 30 m.

How do you calculate volume of a blast?

Page 3

BH + SD. Charge length (C) =
L – SL. Blast volume (V) =
B x S x BH x N. Blasted tonnes (T) =
V x Density of rock in t/m3. Volume of blasthole (Vb) =
π x D2/4000 x L. …
PF (kg/m3) = …
blasted (for kg/Tonne, divided by blasted tonnes T) …
AWS of explosive/AWS of ANFO x 100.

What is a wedge in mining?

i. A cut in which the central holes are positioned to cause the breakout of a wedge-shaped section of strata when fired.