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✳️Cinnabar is a toxic mercury sulfide mineral with a chemical composition of HgS. 🔷It is the only important ore of mercury. It has a bright red color that has caused people to use it as a pigment, and carve it into jewelry and ornaments for thousands of years in many parts of the world. Its […]
🔷Kimberlites, named after the town of Kimberly, South Africa, where they were first described, are volcanic rocks that originate in Earth’s mantle.🔷They are mined exclusively for diamonds. The photo shows the “Big Hole” at Kimberly.🔷The Hole was mined from 1871 to 1914 and reached a depth of 240 m below the surface. Subsequently it filled […]
Geological Time Scale The geological time scale is a system of chronological measurement that relates geological events and geological time to a numerical scale. It is used to describe the timing and relationships between events that have occurred throughout Earth’s history. The time scale is divided into four main parts: Eons, Eras, Periods, and Epochs. […]
What are Rare Earths? The Japanese call them “the seeds of technology.” The US Department of Energy calls them “technology metals.” They make possible the high tech world we live in today – everything from the miniaturization of electronics, to the enabling of green energy and medical technologies, to supporting a myriad of essential telecommunications and defense systems. […]
Geology 101 is the study of the Earth and its materials, structures, processes, and history. It is a broad field that encompasses many different disciplines, including mineralogy, petrology, paleontology, and geophysics. Geologists study the Earth’s physical features, including its rocks, minerals, soils, and water. They also study the Earth’s internal structure and the processes that […]
What is Volcano I heard about the volcano before 🤔??….We all see volcanoes in movies and news, but did you ask yourself why or how do they happen? On our trip today, we will explore the volcano and see its formation, why it happens, and how.. Are you ready, hero ??Let’s start our journey The […]
An unconformity is a surface of erosion or non-deposition that separates two rock units that have different ages. It represents a time gap in the geologic record, and it occurs when sedimentary rocks are tilted, uplifted, and eroded before new sediment is deposited on top of them. There are three types of unconformities: Disconformities A […]
Minerals are homogeneous, naturally occurring, inorganic solids that have a definite crystalline structure and chemical composition. In 1995, the World Minerals Organization put another definition saying that “a mineral is an element or a chemical compound that is naturally crystalline and formed as a result of geological processes.”Minerals have their own specific physical properties which […]
The difference between mineral, metal and ores Many people confuse three completely different classes of substances (minerals, ores, and metals), so that metal becomes a mineral, and all minerals become ores. Minerals Minerals are inorganic solids (elements or compounds) that have distinct physical properties. Each substance has a known atomic structure and a fixed chemical […]
Geology online Quizzes questions and answers. Free online quiz with multiple-choice questions (MCQ) without registration. Geology Multiple Choice Questions geology questions and answers | geology questions for competitive exams | geology exam questions. Geology quiz questions and answers.geology quizes. Geology online quiz.
What is the hydrothermal ore forming?
Hydrothermal ore deposits are minerals that are formed from hot, mineral-rich fluids that circulate through the Earth's crust. These fluids, which are a mixture of water and various dissolved minerals, are heated by magma and other geological processes, and are then expelled from the Earth's interioRead more
Hydrothermal ore deposits are minerals that are formed from hot, mineral-rich fluids that circulate through the Earth’s crust. These fluids, which are a mixture of water and various dissolved minerals, are heated by magma and other geological processes, and are then expelled from the Earth’s interior through vents in the crust.
When these hot fluids come into contact with cooler rocks and minerals, they can deposit minerals such as sulfides, oxides, and silicates in the surrounding rocks. Over time, these mineral deposits can become concentrated and form ore deposits, which can be mined for valuable minerals such as copper, gold, silver, and zinc.
The formation of hydrothermal ore deposits is an important process in the formation of many types of mineral deposits, including porphyry copper deposits, epithermal gold deposits, and volcanic-hosted massive sulfide deposits. These deposits can have a significant impact on the economies of the regions where they are found, and can provide important resources for various industries, including mining, metal production, and electronics.
See lessWhat is the process of ore forming?
All the common ore-forming elements are present in magmas and ordinary rocks, in amounts ranging from a few parts per billion to several thousands of parts per million. Selective concentration of one or more ore constituents to form a mineral deposit is achieved by some combination of the following:Read more
All the common ore-forming elements are present in magmas and ordinary
rocks, in amounts ranging from a few parts per billion to several thousands of
parts per million. Selective concentration of one or more ore constituents to
form a mineral deposit is achieved by some combination of the following:
The ore-forming processes may be grouped into the following four broad
categories:
- Orthomagmatic processes
- Sedimentary processes
- Metamorphic processes
- Hydrothermal processes
See lessWhat is Auger Mining?
⚫Auger Mining 🔷Auger mining means a method of mining coal at a cliff or highwall by drilling holes into an exposed coal seam from the highwall and transporting the coal along an auger bit to the surface and includes all other methods of mining in which coal is extracted from beneath the overburden bRead more
⚫Auger Mining
🔷Auger mining means a method of mining coal at a cliff or highwall by drilling holes into an exposed coal seam from the highwall and transporting the coal along an auger bit to the surface and includes all other methods of mining in which coal is extracted from beneath the overburden by mechanical devices located at the face of the cliff or highwall and extending laterally into the coal seam, such as extended depth, secondary recovery systems
As the auger rotates and advances forward, coal is cut and pushed out of the hole by the rotating action of the auger.
🔹The action is similar to that of a carpenter boring a large hole in wood using an auger bit, and that is where the name derives.
🔷Auger mining recovers around one-third of the coal under the highwall, for whatever depth of penetration is achieved.
🔹 Auger cutting heads can be as large as 7 feet in diameter and may be drilled to a depth of more than 300 feet.
When the ultimate pit limit is reached, it is difficult to “pack up and leave” when you see the exposed coal seam.
🔹 So, in some regard, the company looks at this secondary recovery technique, i.e., auger mining, as the “icing on the cake.
🔹” It amounts to coal recovery at a very low cost. It is, however, somewhat problematic and controversial.
🔷The low recovery, less than 35%, means that the majority of the reserve remains in place, but it has been sterilized, i.e., left in a condition where it will be essentially impossible for anyone to recover the remainder in the future.
🔹The holes into the side of the hill create drainage holes for acid-laden water, and that is a big problem.
See lessWhat is room and pillar mining?
⚒ Room-and-pillar mining ◽️In this method, a number of parallel entries are driven into the coal seam. The entries are connected at intervals by wider entries, called rooms that are cut through the seam at right angles to the entries ◽️ The resulting grid formation creates thick pillars of coal thatRead more
⚒ Room-and-pillar mining
◽️In this method, a number of parallel entries are driven into the coal seam. The entries are connected at intervals by wider entries, called rooms that are cut through the seam at right angles to the entries
◽️ The resulting grid formation creates thick pillars of coal that support the overhead strata of earth and rock.
⚫️ There are two main room-and-pillar systems,
▪️the conventional
▪️ the continuous.
◽️In the conventional system, the unit operations of undercutting, drilling, blasting, and loading are performed by separate machines and work crews.
◽️In a continuous operation, one machine—the continuous miner—rips coal from the face and loads it directly into a hauling unit.
➡️ In both methods, the exposed roof is supported after loading, usually by rock bolts.
◽️Under favorable conditions, between 30 and 50 percent of the coal in an area can be recovered during the development of the pillars. For recovering coal from the pillars themselves, many methods are practiced, depending on the roof and floor conditions.
◽️The increased pressure created by pillar removal must be transferred in an orderly manner to the remaining pillars so that there is no excessive accumulation of stress on them. Otherwise, the unrecovered pillars may start to fail. endangering the miners and mining equipment. The general procedure is to extract one row of pillars at a time, leaving the mined-out portion, or gob, free to subside. While extraction of all the coal in a pillar is a desirable objective, partial pillar extraction schemes are more common.
◽️At depths greater than 400 to 500 meters, room-and-pillar methods become very difficult to practice, owing to excessive roof pressure and the larger pillar sizes that are required.
See less