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? What is Pyrite? Pyrite (FeS₂), commonly known as Fool’s Gold, is a brassy-yellow mineral that resembles gold but has distinct chemical and physical properties. It’s one of the most abundant sulfide minerals and occurs in many types of geological ...
Pentlandite is a significant sulfide mineral and the most important source of nickel worldwide. Recognized for its bronze-yellow metallic luster and association with other sulfides, pentlandite occurs primarily in mafic and ultramafic igneous rocks. Its economic relevance, especially in nickel ...
When it comes to discovering hidden mineral wealth beneath the Earth’s surface, geologists rely on a powerful set of natural clues — one of the most important being alteration zones. These zones, formed by hydrothermal processes, often serve as roadmaps ...
Placer gold mining along the Indus River offers a promising opportunity for gold recovery using natural alluvial deposits. In this guide, we explain how to start placer gold mining, develop an efficient processing plant, and optimize recovery using vibrating classifiers, ...
Understanding Strip Ratio in Surface Mining Introduction In open-pit mining, one of the most fundamental concepts determining the viability and cost-effectiveness of a project is the strip ratio. It is a vital metric that informs whether it is economically feasible ...
1. Introduction to Gossans Definition:Gossans are iron-rich, weathered outcrops formed by the oxidation and chemical weathering of sulfide-bearing mineral deposits. They appear as rusty, reddish-brown to yellow zones on the Earth’s surface and are critical indicators of potential subsurface mineralization. ...
Porphyry copper deposits are among the most significant sources of copper globally, accounting for over 60% of the world’s copper production . 1. Geological Overview a) Geological Background Porphyry copper deposits are typically associated with magmatic arcs related to subduction ...
Introduction Ore-bearing hydrothermal fluids are one of the most important agents in the formation of mineral deposits. These fluids, which originate from various geological processes, have the ability to dissolve, transport, and deposit metals in economic concentrations. The study of ...
Gold has been one of the most sought-after minerals for centuries due to its value and rarity. Prospectors, geologists, and even hobbyists often search for gold-bearing rocks in the field. But how do you identify rocks that contain gold? This ...
What are the other systems of quarrying after bench system?
There are several other systems of quarrying that are used in various parts of the world, including: Room and pillar: In this system, the quarry is developed as a series of interconnected rooms, with pillars left in place to support the overlying rock. The rooms are typically large, rectangular areaRead more
There are several other systems of quarrying that are used in various parts of the world, including:
Room and pillar: In this system, the quarry is developed as a series of interconnected rooms, with pillars left in place to support the overlying rock. The rooms are typically large, rectangular areas that are separated by pillars.
Inclined bench: This system involves the creation of a series of inclined benches, or terraces, on the side of a hill or mountain. The quarry is then developed by removing the rock in a series of horizontal slices, or benches, starting at the top and working downward.
Open-pit: In this system, the quarry is developed as an open pit, with the rock being extracted from the ground using large earth-moving equipment. This is typically used for large-scale operations, such as extracting aggregates or coal.
Sub-level caving: This system involves the creation of a series of underground levels, or sub-levels, in the quarry. As the rock is removed from the sub-levels, the voids are allowed to collapse, creating a natural caving effect. This system is typically used for extracting large, solid blocks of stone, such as granite.
Block caving: In this system, large blocks of stone are extracted from the quarry by creating a series of underground tunnels. As the blocks are removed, the voids created are allowed to collapse, creating a caving effect. This system is typically used for extracting large, solid blocks of stone, such as granite
See lessWhat is basic concept of drilling?
Drilling is the process of making a hole or tunnel into the ground, typically by using a rotary drilling rig. The basic concept of drilling involves the use of a drill bit, which is a device that cuts or chips away at the rock or soil as it is rotated at high speeds. The drill bit is attached to a dRead more
Drilling is the process of making a hole or tunnel into the ground, typically by using a rotary drilling rig. The basic concept of drilling involves the use of a drill bit, which is a device that cuts or chips away at the rock or soil as it is rotated at high speeds. The drill bit is attached to a drill string, which is a long, hollow pipe that is connected to the drilling rig.
As the drill string is rotated by the drilling rig, the drill bit cuts into the ground, creating a hole or tunnel. The drill string is also used to supply the drill bit with drilling fluid, which is a liquid that is used to cool and lubricate the drill bit and to remove the cuttings and debris from the hole as it is being drilled.
Drilling can be used for a variety of purposes, including the exploration and extraction of oil, natural gas, and minerals, the construction of tunnels, and the creation of wells for water or other fluids. Drilling can be performed using various types of drilling rigs, depending on the type of drilling being done and the characteristics of the ground being drilled. Some common types of drilling rigs include rotary drilling rigs, top drive drilling rigs, and drilling platforms
See lessWhat is quarry in mining?
⚒ Modern quarrying processes and techniques ⚒ ⚒ The development of most modern rock quarries involves stripping the overlying soil and weathered rock to get to the hard rock underneath. ⚒ This is then worked in a 'bench' system, removing the rock in layers that can be returned to year after year asRead more
⚒ Modern quarrying processes and techniques ⚒
⚒ The development of most modern rock quarries involves stripping the overlying soil and weathered rock to get to the hard rock underneath.
⚒ This is then worked in a ‘bench’ system, removing the rock in layers that can be returned to year after year as the quarry is developed.
👉 The quarry becomes deeper with each subsequent bench, with stepped benches reaching up to the original surface.
⚒ With few exceptions, modern quarries rely on drilling and blasting to fragment the rock, which is then loaded onto off-highway trucks or belt conveyors for transport to a processing plant of some sort.
Loading is usually done with wheel loaders or excavators, which combine adequate loading capacity with maneuverability.
👉 This allows them to move from area to area within the quarry, as needed. Where blasting results in the formation of large boulders that are too big for the loading equipment to handle, secondary breaking will be needed, either by drilling and blasting individual boulders or by using excavator-mounted hydraulic hammers to break them.
⚒ The exceptions to drill-and-blast include the production of dimension stone, where the demand is for large pieces of rock rather than fragmented material for further processing.
⚒ The production of dimension stone, which is covered on a separate page, involves carefully splitting large blocks of raw stone away from the quarry face, using wedges or diamond-impregnated wire saws. Another exception is where the rock is soft enough to be ripped, using a large dozer or a ripper tine mounted on a hydraulic excavator, with the dozer then being used to push the broken rock onto a hopper or mobile crusher which feeds a belt conveyor system.
⚒ 👉 Quarry design depends on a number of factors including the pre-existing topography, intended output, infrastructure, and environmental footprint.
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 lessWhat is a placer deposit?
⚒️ Placer deposit ⚒️ 💠 Placer deposit, natural concentration of heavy minerals caused by the effect of gravity on moving particles. 💠 When heavy, stable minerals are freed from their matrix by weathering processes, they are slowly washed downslope into streams that quickly winnow the lighter matrix.Read more
⚒️ Placer deposit ⚒️
💠 Placer deposit, natural concentration of heavy minerals caused by the effect of gravity on moving particles.
💠 When heavy, stable minerals are freed from their matrix by weathering processes, they are slowly washed downslope into streams that quickly winnow the lighter matrix.
💠Thus the heavy minerals become concentrated in stream, beach, and lag (residual) gravels and constitute workable ore deposits.
💠 Minerals that form placer deposits have high specific gravity, are chemically resistant to weathering, and are durable; such minerals include gold, platinum, cassiterite, magnetite, chromite, ilmenite, rutile, native copper, zircon, monazite, and various gemstones.
💠 There are several varieties of placer deposits: stream, or alluvial, placers; eluvial placers; beach placers; and eolian placers.
💠 Stream placers, by far the most important, have yielded the most placer gold, cassiterite, platinum, and gemstones.
💠 Primitive mining probably began with such deposits, and their ease of mining and sometime great richness have made them the cause of some of the world’s greatest gold and diamond “rushes.” Stream placers depend on swiftly flowing water for their concentration.
💠 Because the ability to transport solid material varies approximately as the square of the velocity, the flow rate plays an important part; thus, where the velocity decreases, heavy minerals are deposited much more quickly than the light ones.
💠 Examples of stream placers include the rich gold deposits of Alaska and the Klondike, the platinum placers of the Urals, the tin (cassiterite) deposits of Malaysia, Thailand, and Indonesia, and the diamond placers of Congo (Kinshasa) and Angola.
See lessWhat are hydrothermal veins?
The simplest hydrothermal deposit to visualize is a vein, which forms when a hydrothermal solution flows through an open fissure and deposits its dissolved load. A great many veins occur close to bodies of intrusive igneous rocks because the igneous rocks serve as heat sources that create convectiveRead more
The simplest hydrothermal deposit to visualize is a vein, which forms when a hydrothermal solution flows through an open fissure and deposits its dissolved load.
A great many veins occur close to bodies of intrusive igneous rocks because the igneous rocks serve as heat sources that create convectively driven flows in hydrothermal solutions.
Precipitation of the minerals is usually caused by cooling of the hydrothermal solution, by boiling, or by chemical reactions between the solution and rocks lining the fissure.
Some famous deposits are the tin-copper-lead-zinc veins of Cornwall, England; the gold-quartz veins of Kalgoorlie, Western Australia, Australia, and Kirkland Lake, Ontario, Canada; the tin-silver veins of Llallagua and Potosí, Bolivia; and the silver-nickel-uranium veins of the Erzgebirge, Germany.
Hydrothermal deposits formed at shallow depths below a boiling hot spring system are commonly referred to as epithermal, a term retained from an old system of classifying hydrothermal deposits based on the presumed temperature and depth of deposition.
Epithermal veins tend not to have great vertical continuity, but many are exceedingly rich and deserving of the term bonanza.
See lessWhat kind of Soils associated with Gold Deposits?
💠Throughout much of human history, many people have been fascinated with gold. 💠 Almost every civilization has prized this special metal. 💠The first question everyone has is “How do I find gold?” After much effort over the millenia, people have developed lots of ways to find that precious metal. 💠SoRead more
💠Throughout much of human history, many people have been fascinated with gold.
💠 Almost every civilization has prized this special metal.
💠The first question everyone has is “How do I find gold?”
After much effort over the millenia, people have developed lots of ways to find that precious metal.
💠Sometimes, mother nature herself provides hints about where she is hiding some gold.
💠One of these natural indicators can be found by looking at the plants and soil where you think gold might be hidden.
Always remember that gold is rarely found in large chunks.
💠It will either consist of tiny flakes, or as thin streaks of material within rocks.
💠 In fact, prospectors refer to the tiny gold flakes found in river sands as “colors.”
💠Plants Which Might Grow Near Gold
💠The easiest and most common way of searching for gold is known as placer mining.
💠 This refers to finding gold found away from its original underground site and moved over time.
💠 Placer mining is most frequently done either at the bottom of streams or where streams used to flow.
Cottonwood trees, which grow in wet areas will also grow over top of the areas where streams used to flow.
💠Although an old stream bed may be dry on the surface, there may still be dampness underground.
💠Even though the trees don’t necessarily indicate that gold is there, they (or any type of riparian plant for that matter) may help you to locate a placer gold source if you are in gold country.
💠One of the plants which often grow in areas over gold deposits is the horsetail plant.
💠Horsetail plants were often used by miners in the past as a guide to where gold might be found.
💠 It can tolerate the existence of heavy metals in the soil, which has made people believe gold may be nearby.
💠 Ironically, the horsetail plant also had a practical use for prospectors during the gold rush.
💠 It was primarily used for washing pots and pans.
💠The Desert Trumpet is another indicator that helps prospectors know where to look for gold.
💠 They require more mineralization in the soil than most desert plants.
💠 The red dirt the Desert Trumpet grows in is likely near heavy metals like gold.
💠The Trumpet is most commonly found in arid parts of the American Southwest.
See lessWhat are the methods of ore reserve estimation?
Estimates of the tonnage and average grade of ore deposits (ore-reserve estimates) are made for various purposes. They may be made by examining engineers as a basis for placing a value on a mining property in connection with reports on behalf of owners or vendors, on the one hand, or for prospectiveRead more
Estimates of the tonnage and average grade of ore deposits (ore-reserve estimates) are made for various purposes. They may be made by examining engineers as a basis for placing a value on a mining property in connection with reports on behalf of owners or vendors, on the one hand, or for prospective purchasers or lessees, on the other. They are made for tax purposes and sometimes in connection with mergers of two or more companies or with litigation.
Most operating companies make periodical ore-reserve estimates, usually at least annually, to determine their ore-reserve position as a basis for controlling development and exploration and allocation of funds therefor; for determining deferred, depletion, and depreciation charges per ton; or as a basis for deciding upon operating policy—expansion or contraction of operations, capital expenditures, and the like.
The final estimate in any instance usually is a composite of estimates of different blocks or areas which often differ appreciably from each other in grade or character of ore. A continuous ore-reserve inventory, by blocks, levels, and stopes, in a mine may be required as a basis for controlling stoping operations to maintain a desired grade of output by mixing ores from different blocks.
Some mines produce two or more grades or kinds of ore, which must be mined, milled, and shipped separately; and it becomes necessary, then, to know the grade and type of ore available in each section of the mine.
Thus, iron ores are often mixed to give a desired iron, phosphorus, silica, manganese content. The copper-bearing sulfide ores of Ducktown, Tenn., chiefly valuable for their sulfur, are roasted for the manufacture of sulfuric acid; it is necessary to grade the ore from different stopes carefully, on the basis of sulfur content, to form the right mix for this purpose.
Ore-reserve estimates are based upon the results of exploration and development and analyses of the samples derived therefrom. Unless a deposit is fully developed (and even then to a lesser degree), certain assumptions have to be made regarding the continuity and grade of ore between exposed faces or drill holes that have been sampled. In making these assumptions, the engineer must interpret all available information, and the accuracy of the final results will depend largely on his experience and the soundness of his judgment. Not only must he correctly combine the assay values of the samples, but he must, interpret the geological criteria and consider the influence of structural conditions on continuity and grade of ore, the probable loss of ore in mining, the dilution with waste (which, in turn, may depend on the mining method employed or to be employed), and the cost of mining and milling, which may be an important factor in determining the minimum grade of rock that can be classed as ore.
It is apparent, then, that estimation of tonnage and grade of ore reserves is not a precise science. In some districts where the character, uniformity, and habit of the ore bodies have been learned from long mining experience, more or less arbitrary methods may be applied with considerable confidence in estimating ore extending beyond exposed faces. Thus, in Minnesota and Michigan the mining companies and the State tax commissions accept valuations of ore reserves based upon certain rules as to continuity and grade of the ore.
Ore reserve estimates include the determination of (1) tonnages of ore and (2) average grade or value per ton.
See lessWhat chemicals used in phosphate flotation method?
Minerals Engineering Volume 16, Issue 7, July 2003, Pages 577-585 Reagents used in the flotation of phosphate ores: a critical review Author links open overlay panelH.SisaS.Chanderb Show more Share Cite https://doi.org/10.1016/S0892-6875(03)00131-6Get rights and content Abstract Phosphate rock needsRead more
Minerals Engineering
Reagents used in the flotation of phosphate ores: a critical review
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Abstract
Phosphate rock needs processing to reduce the content of gangue minerals such as silicates, carbonates, and clays to meet the requirements of the phosphate industry. Froth flotation method has been an important part of the concentration process since the 1920s and today, more than half of the world’s marketable phosphate is produced by froth flotation. The literature on the processing of phosphate rocks by flotation is critically reviewed. Commonly used collectors, depressants, auxiliary reagents, and their mixtures in the flotation of the phosphate ores were tabulated. The advantages and disadvantages of the reagent type and structure (e.g., ionic and nonionic) on flotation were criticized. Based on the literature it was concluded that using surfactant mixtures has certain advantages over single surfactant as synergistic effect between surfactant mixtures were observed at different experiments such as surface tension, contact angle, adsorption, and flotation.