Natural Stone Quarrying Methods

Quarrying Method with Parallel Pit:

The quarrying stone method using parallel pits at quarry trench is the oldest quarrying stone method from the work chest. In this method, holes number are dug at certain distances from each other in the desired line, which will later be a plane side that can be separated.
The distance between the holes in a row can vary up to several centimeters. This depends on the stone type, specific weight and stone strength. The closer the holes are to each other, the better and more reliable the block will be separated. Of course, from the economic point of view, a large pits number is expensive, and the pits proper distance for each rock type should be obtained with numerous tests. The holes number in each stone block decreases with the length increase and block width.
Therefore, quarrying blocks with greater length and width is more economical, of course, the block size depends on the quarry conditions and equipment and machines. Also, the pit depth depends on the stone type and the desired block height.
For example: the block height granite four-fifths, the block height limestone one-third to one-half, the block height marble two-thirds.
Stone quarrying with the parallel pits help is successfully carried out for deposits that have natural layering and do not need to dig horizontal pits, such as travertine quarries. It is also a suitable method for granite quarries due to the rock hardness. After digging the pits three methods are needed to separate the block from the rock mass.

Block Quarrying Using Pars and Gaveh:

After digging the holes, two metal blades and a strong metal wedge are placed in each one. In this case, the wedge is first placed with the light hammer help. Then, with a hammer weighing 10 kg, the wedge is hit until the stone splits.

Mechanical Block Quarrying:

In this method, a hydraulic hammer type is used to separate the block from the rock mass after digging the holes. With this method, the quarrying time is reduced and less physical strength is required. These hammers have a lot of power and are started with a hydraulic pump. The driving force can be provided by electricity or compressed air. In some cases, the hydraulic pump is driven by a gasoline engine.

Quarrying with Light Materials:

In granite quarries, vertical and horizontal pits are usually dug at appropriate intervals, then a fire is made using special materials and an explosive fuse, and the block is separated from the rock mass. In this method, explosives that have a low specific weight and low explosion speed are used for firing, such as: K-Pipecharg.

Hydromechanical Quarrying Method:

In the hydromechanical quarrying method, water is created by geysers that move with hydraulic motors in the rock. In this method, the water is put under very high pressure and the water flow is sprayed on the stone in the thin stream form with the regular pencil diameter from the special head and rotating hoses, and the kinetic water energy causes the stone to be cut. In some geyser’s types, water comes out of the crater in the pulses form. In this case, the water pressure can be increased to a higher density.

Heat Quarrying Method:

In this method, a 70 to 100 mm thick groove is created with the flame help in the surface depth to be quarried and at different levels. In fact, for stone cutting, the melting property or the stone burning property is used, which is a stone self-parameter. The necessary heat is provided by diesel as the main fuel and compressed air as an aid.
The cutting action is performed by the worker. The flame created hits the stone with a more than 1200 degrees Celsius heat. As an inference result caused by heat, the rock shell is separated and the resulting gases make the particles suspended. The specific fuel consumption in this method is about 40-50 liters for each square meter of the plate to be cut, and considering the high fuel price in most countries and the problems that exist in the protecting workers field from heat and high noise, this quarrying method is not very common and is used only in some granite quarries where the other methods use is also expensive.

Quarrying Method with Steel Cutting Wire:

The cutting use with steel wire has been common since a hundred years ago in large stone quarries in European countries such as Italy. In this method, first, pits with a length of more than 30 meters are dug, which intersect each other at different levels. Then, by passing steel wires through the pits, a confined rock part is cut.
The work is based on the rotational steel wire movement under tension, which cuts the stone with the silica powder and water help. So that this cutting system consists of a driving force device, a guiding pulleys number, a tensioning device and related auxiliary tools. In order to create the necessary tension, the method of hanging a weight on a cart containing a pulley is used. With this method, it is easy to cut horizontal or vertical surfaces by changing the angle given to the reel.

Steel Wire Cutting Method Advantages:

• Cutting large surfaces (in some cases close to 2000 square meters).
• Possibility of using it in distant places possibility by increasing the wire length and conductor coils.
• Possibility of using this method possibility in underground quarries.
• It is possible to cut horizontal or vertical surfaces by changing the angle given to the reel.
• Simple design and maintenance.
• Ability to produce blocks with suitable size and shape.
• Relatively low energy consumption.
• This method has worked well in carbonate stones, including marble cutting.

Steel Wire Cutting Method Disadvantages:

• High personnel and investment costs.
• The facility complexity, which requires sufficient training and experience.
• Water pumping problems.
• Preparing silica powder Problems.
• Low cutting speed (1 square meter per hour).
• Wire High wear and abrasive materials.
• Wires Clumsiness in the operation area.
• Spending a relatively large amount of time to install facilities and equipment.
• Stuck or breaking the wire due to the mountain tensions release and rock expansion.

Sources
• Iranian stone magazine, autumn and winter 2004, numbers 287 and 286.
• Hamidi-Anarki, G., (1375), quarrying methods without mineral materials, Geological Organization.
• Fazel Bastami, K., (2015), natural stone (quarrying), Roshan Rooz Publications.
• Fahimi Far, Jamshid, 1381, “Investigating the natural and decorative stone processing competitiveness units in global markets”, second and third stage report, industrial research, educational and information plan, Industries and quarries. Ministry