Automotive engineering


Download 1.98 Mb.
Sana07.01.2023
Hajmi1.98 Mb.
#1082750
Bog'liq
INDEPENDENT WORK


ANDIJAN MACHINE
BUILDING INSTITUTE FACULTY:” AUTOMOTIVE ENGINEERING” DIRECTION:” BIOMEDICAL ENGINEERING”
3-COURSE GROUP: “BT-0820” MO`MINOVA MADINA INDEPENDENT WORK
Theme:From the quarry to the top of the world
Plane:
ABOUT QUARRY
A quarry is a place where rocks, sand, or minerals are extracted from the surface of the Earth. A quarry is a type of mine called an open-pit mine, because it is open to the Earth's surface. Another type of mine, a sub-surface mine, consists of underground tunnels or shafts.
The most common purpose of quarries is to extract stone for building materials. Quarries have been used for thousands of years. Ancient Egyptians built the Great Pyramids with massive limestone and granite blocks cut by hand from nearby quarries. Each of these blocks weighs many tons. In ancient Rome, slaves and criminals were often forced to do the extremely difficult work of cutting stones in marble, granite, and limestone quarries.
Methods of extracting stone and other materials from quarries have changed since the first quarries were mined in the Aswan area of Egypt. The earliest quarries were mined with hammers, picks, and chisels made of stone or metals such as bronze and iron.
Quarrying material for use in building materials was much more work. Stones had to be carried or dragged out of quarries manually. Stones could also be hauled with pulley systems involving ropes and moveable wooden tracks or sleds. This process often involved thousands of slaves and other workers.
On Easter Island, for example, almost the entire community had to be involved in the quarrying, carving, and transportation of statues. The rock for these statues, called moai, was hauled all over the island from one quarry. The heaviest moai weighs 86 tons. Scientists are still studying how these ancient Polynesian people transported their quarried rock.
Today, people use mechanical tools to mine quarries, including drilling equipment, blasting equipment, and hauling equipment. Industrial drills with diamond tips are used to cut into hard rock. Some miners use explosives to blast away unwanted material to access the desired rock. Finally, materials are hauled away by enormous mining trucks. Some mining trucks can carry more than 350 tons of material.
Large, precisely cut stones excavated from a quarry are called dimension stones. Dimension stones are used for constructing buildings and monuments, or for decorating the outside of buildings. They are also used for kitchen counters and roofing shingles. Headstones, polished dimension stones usually made of granite, are used to mark graves in many countries.
Aggregate is also used to make concrete and asphalt. For this reason, asphalt and concrete plants are often built next to quarries. Asphalt is an oily substance that is mixed with aggregate for road construction. Concrete, invented by the ancient Romans, is a mixture of sticky stone cement and aggregate. The Romans depended on concrete and aggregate to build their vast system of roads and aqueducts, many of which are still standing today.
USED REFERENCES
https://education.nationalgeographic.org/resource/quarry/
https://en.wikipedia.org/wiki/Quarry
THANK YOU FOR YOUR ATTENTION
Download 1.98 Mb.

Do'stlaringiz bilan baham:




Ma'lumotlar bazasi mualliflik huquqi bilan himoyalangan ©fayllar.org 2024
ma'muriyatiga murojaat qiling