The method of extraction appropriate stones from their natural rock beds or layers is often referred to as stone quarrying.
This is completely different from ores mining whereas quarrying is an operation that is carried out totally on the floor, mining involves digging under the ground, typically at appreciable depth.
Stones are natural rock masses or as layers on the surface.
We have to keep the following factors into consideration while deciding about the location of a quarry site as follows:
- Availability of sufficient quantity of desired quality stones.
- It should have proper transport facilities.
- Cheap Local Labor.
- Problems associated with rainwater drainage.
- Location of important and permanent structures in the locality and site to forbid dumping.
Methods of Quarrying of stone:
This quarrying method is appropriate for costly, soft and stratified rocks such as sandstone, limestone, laterite, marble and slate.
Holes about 10–15 cm deep, at a distance of about 10 cm, are made perpendicular to the rock.
Steel pins and wedges or plugs (conical wedges) and feathers are inserted into them.
These plugs are then hit together with a sledge hammer.
Heating is best suited for heating small, thin and regular blocks of stones from rocks such as granite and gneiss.
In a small area the pile of fuel is piled on the rock surface and fired.
Two consecutive layers of rock break apart due to uneven expansion of the two layers.
The loose rock part is broken into pieces of the desired shape and removed with the help of pick-axes and crow-bars.
The obtained stone blocks are very appropriate for rough particles.
Generally, the intermediate layers should be separated from the highest and backside layers.
In such a case, the intermediate layer is electrically heated and the expansion separates from the other two.
A quarrying of stone has a rough surface that is prepared to obtain a fixed and regular shape.
The dressing of the stones is finished immediately after the quarry and before the season to acquire much less weight for transport.
Dressing of stone:
The stone dressing provides a delightful look with particular shapes for good mortar joints, arches, imitations, pillars and many others.
The dressing of stone is defined as the method of cutting, roughly damaged stones obtained from the quarry to an applicable measurement, shape, and finish.
Types of Dressing:
The stone dressing could be achieved both as well as mechanically.
Manually, skilled stone-smiths can work wonders on chisels and appropriate sorts of stones with hammers and abrasives.
Mechanically, machines can minimize the stone to any desired shape and measurement.
Their surfaces could be made extra clean by sharpening through machines, however there are some traditional types of stone dresses which are also quite popular at present.
In pitched dressing, the edges of a stone block are leveled with the help of a hammer.
The superficial mass on the face is usually intact.
It is a type of dressing in which large raised parts of the stones break and the stones are somewhat flat but rough due to hammer marks.
These stone segments are squared, and the bed and vertical sides are dressed 8 to 10 cm from the face, to enable proper jointing of the stone.
This work is done using the Waller’s hammer, the received stones are faced with a hammer, quarry faced or rustic faced.
The edges are first divided using a chisel and hammer.
A sequence of variable width grooves is developed on the stone surface.
On this method of stone dressing about 1 cm of vertical or horizontal grooves are submerged with a chisel, it is formed as a hollow semi-circle.
The edges of the cliff are chamfered or sunk.
This is done on stones that are already rough tools with the help of a chisel, a series of parallel ridges are developed on the surface of the stone, also known as the furrowed finish.
Close Picked and Fine Dressing:
It is an extreme type of stone quarrying in which almost every projectile is removed from all sides of the stone.
Its surface has been given a great texture and attractive look.
Boasted or droved Dressing:
This is a very common type of stone dressing, in which the surface of the stone is covered with parallel marks that can run in any direction.
A bolster which is actually a wide-edged chisel is used for this purpose.
These marks may be horizontal or at any angle, chisel marks are not continuous across the entire width of the stone.
The irregular edges of the stones are broken, and the stone is shaped.
This work is usually done in a mine, and the edges are broken by a scrambling hammer.
This type of stone has a 2 cm wide margin within the central part of the irregular shaped sinking stones.
These sinks are about 6 mm deep, eccentric surfaces can be punched to give a better appearance.
This dressings of stone resemble reticulated finishes, except that they are more curved and give the appearance of a worm-eaten type.
This is not very common because they require a lot of labor to manufacture.
Combined or Dragged Dressing:
This type of finish is done on soft stones.
A comb is applied to the surface of this stone to remove all the elevated parts.
This type of dressing of stones is obtained by finishing the stone with some extent and the depression is smaller than the above type.
Moulding is completed to enhance the appearance of the stones.
These are both handmade and machine-made.
On this method of stone quarrying, the surfaces of the stones are rubbed for an easy end.
One piece of stone is rubbed against another, water and sand are added to help the operation.
It can also be rubbed with hands or machines.
Stones that can be polished such as granite, stone, limestone, etc., are first rubbed using rubber, pads, sand, water and putty powder.
However, a machine can also be used for polishing.
Quarrying of stones by Sand blasting:
This method of stone dressing is done to imprint letters and designs on the surface of granite.
The polished surface is coated with a compound such as molten rubber that freezes when cooled.
The specified design on this coating minimizes with a sharp device, exposing the surface of the stone that is to be minimized.
An explosion of sand is then blown with compressed air, the half-exposed is minimized to the required depth.
Tools for Quarrying of Stone:
The following tools are required within the blasting process:
It is used to drill a gap to the required depth.
It is used to make blast holes, more effective in boring vertical holes round.
(3) Priming needle:
It is used for retaining holes when the tamping is being tapped as a skinny copper rod pointed at one end and a loop is provided on the other end for handling.
After the hole has been filled with explosives, the hole is filled with tempered earth and this needle is placed in the center so that a path is developed for the insertion of the fuse due to explosion by its removal or extraction.
(4) Scrapping Spoon:
It is used to remove the crushed stone dust from blast holes.
It is within the type of an iron rod with a round plate attached at one end and a loop is provided on the different end to facilitate its handling.
(5) Tamping Bar:
It is used to ramp or tamp the material while refilling blast holes.
It is in the form of a heavy brass rod of 10 mm to 15 mm diameter and it tapers slightly at the ends.
Stone quarrying is the surface extraction of a wide range of minerals and extraction is the general term for obtaining minerals from the continental crust of the earth.
Large surface operations are called open-pit mining.
Extraction of minerals below 1 km below the surface is called underground mining.