دورات هندسية

 

 

Acanthite-actinolte-adamite-adularia-aegirite

صفحة 2 من 3 الأولىالأولى 1 23 الأخيرةالأخيرة
النتائج 11 إلى 20 من 24
  1. [11]
    alshangiti
    alshangiti غير متواجد حالياً

    مشرف وإستشاري هندسة المناجم


    الصورة الرمزية alshangiti


    تاريخ التسجيل: Mar 2007
    المشاركات: 1,472

    وسام مشرف متميز

    Thumbs Up
    Received: 89
    Given: 8
    Explosives - Mining Types

    Most of the explosives and blasting agents sold in the US are used in mining. There are two classifications of explosives and blasting agents. High explosives include permissibles and other high explosives. Permissibles are explosives that the Mine Safety and Health Administration approved. Blasting Agents and Oxidizers include ammonium nitrate-fuel oil (ANFO) mixtures, regardless of density; slurries, water gels, or emulsions; ANFO blends containing slurries, water gels, or emulsions; and ammonium nitrate in prilled, grained, or liquor form. Bulk and packaged forms of these materials are contained in this category. In 1998, about 95% of the total blasting agents and oxidizer were in bulk form.
    The principle distinction between high explosives and blasting agents is their sensitivity to initiation. High explosives are cap sensitive, whereas blasting agents are not.
    Many coal mines use explosives to loosen the rock and coal. In surface mining, holes are drilled through the overburden, loaded with explosives, and discharged, shattering the rock in the overburden. In one underground mining method, the coal is blasted off the bed without any undercutting to help break it down. The drawback to this method is that a dangerously large explosive charge is needed, and much dust and fine coal are produced. In another underground mining method using explosives to break down the coal, shot holes are drilled at intervals along the face of the coal bed. The explosives are inserted in these holes or shots. When the explosion occurs, the coal wall cracks into pieces. Coal mines use cylinders of compressed air, liquid carbon dioxide, or chemical explosives. Approximately 1.72 million metric tons (Mt) of explosives used for coal mining in 2000. This accounted for 67 percent of total U.S. explosives consumption. The largest coal producing states, Wyoming, West Virginia, and Kentucky were also the largest explosives-consuming states, accounting for 41 percent of total U.S. explosive sales.
    Quarrying and nonmetal mining, the second-largest explosives-consuming industries, accounted for 14 percent of total explosives sales and metal mining accounted for 9 percent. Kentucky, Wyoming, West Virginia, Virginia, and Indiana, in descending order, were the largest consuming states, with a combined total of 51 percent of total US sales of explosives.
    Cast Blasts


    Explosive casting is the technique used by many surface coal mines to control the displacement of overburden by means of explosive energy. The casting moves 30-80% of the overburden into the mined-out pit, while the remaining spoil is removed by draglines or other machinery. A blasting engineer must consider bench height, pit width, borehole diameter, and geologic formation when designing a cast blast. In most cases, the blaster uses a complicated sequence of downhole and surface delays to minimize the ground roll associated with the large amounts of explosives (between 0.5-8 million pounds, ie, 500 to 4,000 tons, of Ammonium Nitrate Fuel Oil ANFO) used in a cast blast. The casting of the overburden into the pit creates both horizontal and vertical spall force components that influence the generation of surface waves.
    Kiloton class mine blasts are not uncommon in numerous regions worldwide such as Wyoming, Kentucky and, at least historically, the Kuzbass mining region in Russia. These use delay-firing and thus a considerable explosive yield is spread out over several seconds and seismic amplitudes are reduced. It is well known that minor deviations from the planned shot pattern are obiquitous. A small subset of these events, however, include a significant detonation anomaly.
    Fragmentation Blasts

    The majority of hard rock open-pit mines design blasts that will optimize the insitu fragmentation of the material. This is accomplished by loading the holes with two different energy levels: higher energy explosives in the bottom and lower energy near the top. The result is that the material is not thrown into the mined-out pit as in the cast blasts. Instead, the material is fractured in place and removed with shovels and haul trucks. Seismic waves generated from a fragmentation blast should be influenced only by the explosion point and vertical component spall forces.
    Quarry Blasts

    A third type of explosion used in the mining industry is for quarrying materials such as limestone, gravels, and igneous rocks. On average, quarry blasts are smaller in spatial extent and explosives ******* than fragmentation and cast blasts. Since these operations usually involve the crushing of the rock, efficient fragmentation of the rock into small pieces is required for use in a rock crusher. For ease in extraction of the materials, the rocks are usually blasted into the mined-out pit. Quarrry blasts seismograms will thus have both horizontal and vertical spall forces effecting the regional seismograms.

    Classification of Mining Explosions

    When the eject angle is 0°, there is no horizontal spall component and the blast is analogous to a fragmentation shot. For quarry blasts, there is some material cast into the pit at eject angles greater than 45°, however, a additional amount of the spalled material is cast into the air at angles between 0 and 30°. Finally, for cast blasts, the majority of the material is ejected at angles greater than 30°. Cast blasts will have the largest deviation from an isotropic source (i.e., a fragmentation blast) with the magnitude of the azimuthal variations being dependent upon the eject angle. In all cases, there is a slight increase in the amplitudes in the direction of the delay-firing. For the cast blasts to take on a more di-polar ("peanut-shaped") radiation pattern, the mass of the horizontal spall must be increased. By adding additional rows of explosives with different interrow and interhole delays, the characteristics can become markedly different.

    0 Not allowed!



  2. [12]
    alshangiti
    alshangiti غير متواجد حالياً

    مشرف وإستشاري هندسة المناجم


    الصورة الرمزية alshangiti


    تاريخ التسجيل: Mar 2007
    المشاركات: 1,472

    وسام مشرف متميز

    Thumbs Up
    Received: 89
    Given: 8
    Explosives - ANFO (Ammonium Nitrate - Fuel Oil)

    Mining is the search for, extraction, and beneficiation and processing of solid minerals from the earth. The kinds of minerals extracted from the earth vary widely. For thousands of years, these and other minerals have provided the raw materials with which human civilizations have been built.
    The vitality of the U.S. economy depends on key mineral resources. In the course of a lifetime, each American will use 3.5 million pounds of minerals, metals, and fuels. Every year, 46,000 pounds of new minerals including 7,500 pounds of coal energy must be provided for every person in the U.S. to maintain a high standard of living. Low-cost coal is used to generate a large portion of the nation's electricity supply, helping to keep U.S. electricity costs among the lowest in the world and thereby enhancing the competitiveness of U.S. industry. The contribution that the mining industry has made to the economic health, well being, and security of the U.S. throughout its history is unquestioned.
    Surface mining and underground mining are the prevailing mining methods. The method selected depends on a variety of factors including the nature and location of the deposit as well as the size, depth, and grade of the minerals. Both surface and underground mining are widely used in the extraction of coal. In 2000, the total amount of coal produced was 1.07 billion tons. Of this, 373 million tons or 35 percent came from underground mines and the remaining 699 million tons or 65 percent came from surface mines. Of the 1.3 billion crude metal ore produced in the US in 2000, 1.2 billion tons or 92 percent came from surface mining. Most of the industrial minerals in the US are extracted by surface mining. In 2000, the total amount of crude industrial ore mined in the US was 3.2 billion tons. Of this, 3.1 billion or 96 percent came from surface mines.
    Bingham Canyon near Salt Lake City, Utah, is probably the best-known example of a surface mine in the U.S. It is also the largest surface mine in the US, measuring approximately 2 miles in diameter and a little more than a half mile deep. Conical in shape and used for near-surface ore bodies, these mines feature a series of benches winding down into the pit. The benches are used as working areas and haul roads. The rock is drilled, blasted and loaded into large haul trucks that take it to a processing facility.
    Underground mining is used when mineralization is deep beneath the surface and/or when ore grade or quality is sufficient to justify more targeted mining. In order to get to the ore body, a vertical shaft, horizontal adit, or inclined passageway must be drilled remove ore and waste and provide ventilation. Once the ore body is exposed, several levels of horizontal tunnels called drifts and crosscuts are created to provide access to mining areas called stopes. The area actually being mined at any given time is called the face. Broken rock is hauled from the face by trains, loaders, or trucks that go directly to the surface, or to the shaft where it is hoisted to the surface and sent to a processing facility.
    There are seven general phases of the mining process. These are: 1) mine exploration; 2) design; 3) construction, which includes mine site preparation; 4) extraction operations in either underground or surface mines; 5) beneficiation operations consisting of crushing and grinding, separations, solvent extraction/electrowinning; 6) processing, which consists of smelting and/or refining depending on the mineral and the final product; and 7) reclamation (closure and post-closure). In each of these stages, there are a variety of equipment and materials used.
    Exposives and Coal Mining

    Coal is extracted principally in two ways: surface mining and underground mining. The mining method used depends primarily on the depth of the coal bed from the surface and the surrounding terrain. Coal beds deeper than 100 to 200 feet or on hilly terrain are usually mined by underground methods, while those at lesser depths are surface mined. Surface mining accounts for about 60 percent of the total U.S. coal production of 1 billion tons/year. A large surface mine can be three miles long and a mile wide. Underground mining accounted for 430 million short tons in 1998, about 40 percent of total US coal production that year.
    Coal fields in the eastern U.S. are characterized by relatively thin seams of deeply buried coal. Eastern coal generally has a high heating value. Conversely, relatively thick seams of shallow reserves characterize the coalfields in the western U.S. Western coal generally has a low heating value. These deposit characteristics also greatly influence the mining method used. Underground mining is more frequently used on the thinner seams of the eastern coalfields. However, surface mining is most frequently used in the West. These deposits require relatively low-volume, shallow digging to expose thick coal seams for recovery.
    In general, where favorable coal seam conditions exist, surface mining is the least expensive and most productive method of taking coal from the ground. Used when the coal seam is relatively close to the surface, it can result in the removal of as much as 95 percent of the total coal from a particular deposit.
    Area surface mining is done on relatively flat land under which the coal is buried at roughly uniform depth. In this method, the overburden from a 100- to 200-foot-wide cut is used to fill the mined-out area of the preceding cut. Contour surface mining follows coal beds lying in hillsides. Excavation begins at a location where coal and surface elevations are the same. It proceeds towards the center of the hill or mountain until the overburden becomes too thick to remove economically. Mountain top removal mining is used to recover coal buried at or near the summit of a large hill or mountain by entirely removing the elevated area.
    Most surface mines follow the same basic steps to produce coal. Bulldozers clear and level the mining area; topsoil is removed and stored for later use in the reclamation process; holes are drilled through the overburden, loaded with explosives and discharged, shattering the rock in the overburden; power shovels or draglines clear away the overburden until the coal is exposed. The dragline has a large bucket suspended from the end of a boom, which may be as long as 300 feet. The bucket, which is suspended by cables, is able to scoop up to 250 tons of overburden as it is dragged across the excavation area. The dragline is one of the largest land-based machines in the world. Smaller shovels then scoop up the coal and load it onto trucks, which carry the coal to the preparation plant.
    Exposives and Iron Mining

    Iron is found in every state in the United States and in almost every country in the world. However, the ore must contain commercially recoverable amounts of iron in relatively large deposits or ranges if it is to be mined economically. The characteristics of iron-bearing ores vary geographically. Specifically, magnetite and hematite are the main iron-bearing ores in the Lake Superior district and in the northeastern United States, while hematite and hematite-magnetite mixtures tend to be found in ores in Alabama and the Southwest.
    To be competitive, iron mining must be done on a very large scale. Surface mining is the preferred choice, although there are exceptions. Small, low-capacity mines have rapidly disappeared.
    In 2000, twelve iron ore production complexes with 12 mines, 10 concentration plants, and 10 pelletizing plants were operating in Minnesota, Michigan, and six other States. The mines included eleven surface and one underground operation. Virtually all ore was concentrated before shipment. Nine mines operated by five companies accounted for 99 percent of production.
    When the iron ore lies close to the surface, it often can be uncovered by stripping away a layer of dirt, sometimes only a few feet thick. The ore is mined from large open pits by progressive extraction along steps or benches. The benches provide access to progressively deeper ore, as upper-level ore is removed. After the soil and overlying rock are cleared, the ore is drilled and blasted. The portion of the ore body to be removed is first drilled in a specific pattern, and the holes are loaded with explosive mixtures and blasted. Following blasting, the fractured ore is loaded by huge electrical shovels, hydraulic excavators, or front-end loaders onto large dump trucks. The wide holes in the ground created by drilling, blasting, and ore removal are referred to as "open pits".
    Exposives and Copper Mining

    For nearly 5,000 years, copper was the only metal known to man. It remains one of the most used and reused of all metals. The demand for copper is due to its good strength and fatigue resistance, excellent electrical and thermal conductivity, outstanding resistance to corrosion, and ease of fabrication. Copper offers moderate levels of density, elastic modulus, and low melting temperature. It is used in electrical cables and wires, switches, plumbing, heating, roofing and building construction, chemical and pharmaceutical machinery. It is also used in alloys such as brass and bronze, alloy castings, and electroplated protective coating in undercoats of nickel, chromium, and zinc.
    Copper is commonly extracted from surface, underground and increasingly, from in situ operations. In 2000, the principal mining States, in descending order, Arizona, Utah, New Mexico, and Montana, accounted for 99 percent of domestic production. Copper was also recovered at mines in three other States. Although copper was recovered at about 30 mines operating in the United States, 15 mines accounted for about 99 percent of production. At 2001 year end, four primary smelters, four electrolytic and four fire refineries, and 15 solvent extraction-electrowinning facilities were operating.
    Surface mining requires extensive blasting as well as rock, soil, vegetation, and overburden removal to reach lode deposits. Benches are cut into the walls of the mine to provide access to progressively deeper ore as upper-level ore is depleted. Ore is removed from the mine and transported to beneficiation plants for milling and concentrating. The concentrate is then smelted and refined. Open-pit mining is the primary domestic source of copper.
    Exposives and Crushed RockMining

    Crushed rock is one of the most accessible natural resources and a major basic raw material. It is used in construction, agriculture, and other industries using complex chemical and metallurgical processes. Despite the low value of its basic products, the crushed rock industry is a major contributor to and an indicator of the economic well being of the nation.
    Most crushed and broken stone is mined from open quarries; however, in many areas, factors favoring large-scale production by underground mining are becoming more frequent and prominent.
    Surface mining equipment varies with the kind of stone mined, the production capacity needed, the size and shape of the deposit, estimated life of the operation, location of the deposit with respect to urban centers, and other important factors. Typically, drilling is done with tricone rotary drills, long-hole percussion drills, and churn drills. Blasting in smaller operations may be done with dynamite, but in most medium-to large-size operations, ammonium nitrate fuel oil mixture (AN-FO) is used as a low cost explosive. The rock is then extracted using power shovels or bulldozers.
    Typical blasts at quarries use a 3½ inch diameter hole approximately 40 feet deep. The explosive most commonly used is ANFO and the top part is stemmed with sand/gravel or drilling cuttings poured on top of the ANFO to help force the blast energy into the rock. The amounts of ANFO and stemming vary depending on the location of the hole in the blast pattern, site conditions, the hardness of the rock to be blasted, and of course, on PPV limitations for surrounding structures. Generally, a minimum amount of stemming for a 3½ inch diameter, 40 foot hole would be approximately 7 feet, which would leave 33 feet of hole for ANFO. The weight of explosives in the hole would be approximately 115 pounds.
    About three-quarters of the crushed stone production is limestone and dolomite, followed by, in descending order of tonnage: granite, traprock, sandstone and quartzite, miscellaneous stone, marble, slate, calcareous marl, shell, volcanic cinder and scoria.
    Limestone, one of the largest produced crushed rock, is a sedimentary rock composed mostly of the mineral calcite and comprising about 15 percent of the earth's sedimentary crust. This mineral is a basic building block of the construction industry and the chief material from which aggregate, cement, lime, and building stone are made. For the purposes of this report, limestone will be used as a sample for crushed rock.
    One product of limestone mining is lime. A wide range of industries use lime for a myriad of uses. It is used in many of the products and materials Americans use every day, including paper, steel, sugar, plastics, paint, and many more. The largest single use of lime is in steel manufacturing, for which it serves as a flux for removing impurities (silica, phosphorus and sulfur) in refining steel

    0 Not allowed!



  3. [13]
    alshangiti
    alshangiti غير متواجد حالياً

    مشرف وإستشاري هندسة المناجم


    الصورة الرمزية alshangiti


    تاريخ التسجيل: Mar 2007
    المشاركات: 1,472

    وسام مشرف متميز

    Thumbs Up
    Received: 89
    Given: 8
    Underground rock excavation.

    Tunneling.

    Tunneling is the most frequently occurring underground operation which also forms part of the construction of rock chambers etc. and is normally an integral part of mining operations. Tunnels can be divided into three categories on the basis of the size of their cross sections:

    · Small tunnels, 4 – 20 m².
    · Medium size tunnels, 20 – 60 m²
    . Large tunnels, over 100 m²

    Small tunnels
    Drilling and blasting.
    The smallest practical cross section of a tunnel is around 4 m². This area gives space for ventilation tubing and small excavation equipment.

    Tunnel areas of 4 to 6 m².
    Handheld pusher leg drilling equipment is preferred.

    Atlas Copco manufactures three reliable and efficient pusher leg drilling machines for different rock characteristics:


    • BBC 16W (Puma). An all-round drill which suits most drilling applications.
    • BBC 34 W (Leopard). A highly efficient rock drill for medium to hard rock.
    • BBC 94 W (Panther). A high performance rock drill for soft to hard rock.




    The drilling pattern is preferable a parallel hole cut pattern drilled with:

    • integral drill steel series 11 or
    • integral drill steel series 12 or
    • tapered rods with button bits or insert bits of 38 mm diameter.
    For the large hole in the parallel hole cut the large hole is reamed to 64 or 76 mm.

    The drilling pattern of such a small tunnel contains of the cut and the contour holes.
    The number of holes is 26 + 1 large hole if the walls and roof are smooth blasted. If not smooth blasted the number of holes
    is 21+1.


    Drilling pattern. Firing pattern.

    Suitable explosives: Cartridged dynamite or emulsion explosive in the cut and stoping holes. Smooth blasting explosive with 17 mm diameter in the contour holes or 40 to 80 gr/m detonating cord.
    Suitable detonators: Non-electric detonators type NONEL.

    Tunnel area 6 – 20 m².
    When the cross section increases it is possible to use more efficient drilling equipment. Atlas Copco provides three powerful drill rigs for small tunnels:


    • Rocket Boomer 104-1238, a single boom, small size rig for tunnel areas
      of 6 to 20 m².
    • Boomer 281, a single boom, high capacity rig for tunnel areas of 6 to 31 m².
    • Boomer 282, a twin boom, high capacity rig for tunnel areas of 8 to 45 m².

    The drill rig may be rail bound or


    on rubber wheels.



    The drilling pattern is drilled with a parallel hole cut. The blasthole diameter is suggested to 48 mm, and the drill depth 3.30 m with T32 drillrods of 3.66 m length. Large hole diameter is suggested to 76 mm.




    Drilling pattern.



    Firing sequence.

    The drilling pattern is shown on a 16.2 m² tunnel area. The number of holes is 45 + 1 if walls and roof are smooth blasted. For normal blasting without smooth blasting, the number of holes are 37 + 1.
    Suitable explosives: Dynamite, emulsion explosives or slurry explosives in cartridges. For more efficient loading work blowable ANFO or pumpable emulsion explosives may be used.
    Initiations system: Preferably a non-electric shock tube system.

    Medium size tunnels
    20 - 60 m²

    Medium size tunnels are common in construction of hydro electric power plants, construction of roads etc.





    Atlas Copco provides a wide range of drill rigs for mid size tunnelling.


    <LI type=disc>Rocket Boomer 282, a twin-boom hydraulic drill rig for tunnel areas of 8 – 45 m². <LI type=disc>Rocket Boomer M2, the next generation of high power twin-boom hydraulic drill rigs for tunnel areas up to 45 m². <LI type=disc>Rocket Boomer L2, another drill rig of the next generation of high power hydraulic drill rigs for tunnel areas up to 90 m²

    ABC “Basic”:
    The operator moves the booms and feeds.This function displays the feed angles only the vertical and the horizontal. On the operator’s screen, a target board is displayed. On this board the feed is represented as a straight line. The length and inclination of this line represent the feed inclination.

    ABC “Regular”:
    The operator moves the booms and feeds. This function records and displays for each hole,

    <LI type=disc>the point of collaring of the hole <LI type=disc>the direction of the hole <LI type=disc>the hole depth <LI type=disc>the actual penetration rate

    Other parameters, which are recorded but not shown on the screen, are

    <LI type=disc>hole number <LI type=disc>hole type (contour, bottom, cut, bolt, etc ) <LI type=disc>drilling time per hole <LI type=disc>actual penetration rate recorded at regular intervals <LI type=disc>different types of hydraulic pressures such as feed, impact, rotation

    All these parameters are continuously being recorded on a PCMCIA card from which it can be dumped into a computer in the office for record and analysis.

    ABC “Total”:
    The computer controls the movements of the booms and the feeds. However the operator has the option to take over the control at any time.

    All parameters mentioned under ABC Regular are recorded. The drilling process follows a), b) and c). However when designing the drill-pattern a) one more information is required, the sequence in which the holes will be drilled has to be programmed. In this version of ABC the booms and feeds are moved between the holes by the computer as per sequence defined in the drill-pattern. The perator however has the possibility to take over the control at any time by moving the levers for that function.

    Picture of operator’s panel on Boomer L2C

    The drilling pattern is drilled with a parallel hole cut and the suggested blasthole diameter is 48 mm and the drill depth is 5.2 m with R32 of 5.53 m length in good ground conditions.




    Drilling pattern and firing sequence.

    Large hole diameter is suggested to 89 mm with 2 large holes in the cut. The tunnel area is 59 m² and the number of blastholes is 82. Suitable explosives: ANFO or pumpable emulsion explosives of SSE (Site Sensitised Explosives) type in the cut and stoping holes. Walls and roof should be blasted carefully to avoid overbreak. Suitable explosives are 17 mm pipe charges or 40 – 80 gr/m detonating cord. With high efficient drilling equipment, loading of the blast should also be efficient to keep down the time of the work cycle. SSE explosives has the advantage of not being an explosive until it is pumped into the blasthole. The charge concentration may be changed in the hole so that no special explosive is needed in the contour holes. For efficient loading work with the SSE loading truck the service platform of the drill rig may be used together with the loading equipment of the SSE loading truck. Initiation system: Preferably a non-electric shock tube system.




    Drilling and firing pattern for a horse shoe shaped tunnel..

    The drilling pattern is drilled with a parallel hole cut and the suggested blasthole diameter is 45 mm and the drill depth is 5.2 m with R32 of 5.53 m length. Large hole diameter is suggested to 89 mm with 3 large holes in the cut. The tunnel area is 42 m2 and the number of blastholes is 90. Suitable explosives: ANFO or pumpable emulsion explosives of SSE (Site Sensitised Explosives)
    type in the cut and stoping holes. Walls and roof should be blasted carefully to avoid overbreak.

    Suitable explosives are 17 mm pipe charges or 40 – 80 gr/m detonating cord. With high efficient drilling equipment, loading of the blast should also be efficient to keep down the time of the work cycle. SSE explosives has the advantage of not being an explosive until it is pumped into the blasthole.

    The charge concentration may be changed in the hole so that no special explosive is needed in the contour holes. For efficient loading work with the SSE loading truck the service platform of the drill rig may be used together with the loading equipment of the SSE loading truck.Initiation system: Preferably a non-electric shock tube system.

    0 Not allowed!



  4. [14]
    alshangiti
    alshangiti غير متواجد حالياً

    مشرف وإستشاري هندسة المناجم


    الصورة الرمزية alshangiti


    تاريخ التسجيل: Mar 2007
    المشاركات: 1,472

    وسام مشرف متميز

    Thumbs Up
    Received: 89
    Given: 8
    Sorry the drawing not attached

    0 Not allowed!



  5. [15]
    alshangiti
    alshangiti غير متواجد حالياً

    مشرف وإستشاري هندسة المناجم


    الصورة الرمزية alshangiti


    تاريخ التسجيل: Mar 2007
    المشاركات: 1,472

    وسام مشرف متميز

    Thumbs Up
    Received: 89
    Given: 8
    Rock Reinforcement
    Swellex in Mining
    Swellex is the most cost-effective rockbolt in mining operations, both in development and cultivation works. For these sound reasons:

    1. Swellex grips to the irregularities of the drilled hole and gives immediate full-column, full loading capacity.
    2. Swellex can accommodate large ground movement and shear displacement.
    3. Manual installation is easy, fast and does not require heavy equipment.
    4. With mechanized bolt installation, Swellex dramatically reduces unproductive time, problems and wear part consumption of bolting rigs.
    5. Swellex is insensitive to blasting and variations in bore hole diameter.
    6. Swellex is versatile and can be used in any excavation geometry.
      Slope stabilization/ Soil Nailing
    Pit walls and rocky slopes often present large fractures and open cracks, loose blocks and hanging wedges. Large quantities of grout can disappear into the voids. Swellex bridges open cracks and anchors the rock on either sides of the crack. With Swellex, slopes can be contained and drained at the same time, thanks to the longitudinal free area left in the hole by its profile.
    • In soft rock and soil the expansion of Swellex increases compactation of the surrounding material, obtaining high load capacity even in loose material.

      Wire mesh can be installed at any time on pre-installed bolts with the simple mesh washer available with Swellex. Just hang your mesh and install the washer, without having to drill additional holes. Swellex can be delivered, as complete bolt, up to 12 meters long; Connectable Super Swellex can also be used if long bolts are required.

      The Swellex high pressure pump can be used to perform a fast, inexpensive and non-destructive quality control test, even long time after the installation.




    0 Not allowed!



  6. [16]
    أبو حمزة السلفي
    أبو حمزة السلفي غير متواجد حالياً
    مشرف متميز
    الصورة الرمزية أبو حمزة السلفي


    تاريخ التسجيل: Dec 2007
    المشاركات: 396

    وسام مشرف متميز

    Thumbs Up
    Received: 53
    Given: 316
    السلام عليكم
    روووووووووووعة مواضيع تحتاج لكورسات فقط لدراستها فضلاً عن استظهارها

    مناقشة :
    1- لاحظت عند تصميم دورات التفجير لفتح الأنفاق دائما هناك ثقب أو ثقبين يتركان بدون شحنهما
    بالمتفجرات لماذا؟؟ هل هو لترك مجال للصخور لتتكسر داخله


    2- نريد تفصيل عن أنواع التأخير (delay) في التفجير المستخدم في فتح الأنفاق وفي المناجم
    السطحية و أهم طرق تصميم دورات التفجير وحسب ما أذكر في أيام الدراسة كان هناك طريقتين
    مشهورتين في تصميم دورات التفجير في المناجم السطحية وهما الطريقة الأمريكية والطريقة
    السويدية


    3- لاحظت أن كل طرق فتح الأنفاق التي ذكرتها تفتح كاملة في مرة واحدة (Full face) وإن كان
    النفق ذو أبعاد كبيرة إذ أظن أن في هذا نظر قوي لأنه قد يحدث له انهيارات لو لم يجزأ فتح النفق
    إلى مرحلتين أو ثلاث حسب ما أذكر إذ يتم فتح الجزء العلوي أولا ثم الجزء السفلي في مرحلتين أو
    أكثر (Top heading & bench) أو قد يجزأ حتى الجزء العلوي في فتحه كذلك (Centre
    crown drift followed by two crown side drift then by the
    bench in one, two or three stages )

    4- لم ترد على طلبي في تطبيقاط الإسقاط الإستيريوغرافي (Stereographic Projection)
    في اتزان المنحدرات وتصميم الأنفاق

    5- في ما يخص بالمنحدرات وطرق تثبيتها هل هناك أنواع أخرى تستخدم غير مسامير Swellex
    وهل تستخدم مسامير Swellex في الأنفاق

    6- سؤال شخصي : هل أنت من شنقيط موريتانيا بلد العلم والعلماء كالشيخ العلامة محمد الأمين
    أم هو لقب فقط ؟؟؟؟؟!

    0 Not allowed!



  7. [17]
    alshangiti
    alshangiti غير متواجد حالياً

    مشرف وإستشاري هندسة المناجم


    الصورة الرمزية alshangiti


    تاريخ التسجيل: Mar 2007
    المشاركات: 1,472

    وسام مشرف متميز

    Thumbs Up
    Received: 89
    Given: 8
    1-هذة الثقوب هى الوجة الحر فى المناجم السطحية وهى ما يسمى opening
    2-سوف اقوم لا حقا بعرض بعض المعلومات عن انواع التأخير

    3- كل طرق فتح النفاق التى تستخدم الحفر يكو ن التفجير مرة واحدة وهى تعتمد على ان تكو ن كل الحفر محفورة ومتوازية وباستخدام delay جيد وستكون النتيجة جيدة اذ العملية تحتاج فقط الى الخبرة .
    4-نعم هناك انواع كثيرة غير SWELLEX وهى تستخدم فى الأنفاق حسب نوعية الصخور .
    5- نعم أنا من شنقيط ولك تحياتى .

    0 Not allowed!



  8. [18]
    alshangiti
    alshangiti غير متواجد حالياً

    مشرف وإستشاري هندسة المناجم


    الصورة الرمزية alshangiti


    تاريخ التسجيل: Mar 2007
    المشاركات: 1,472

    وسام مشرف متميز

    Thumbs Up
    Received: 89
    Given: 8
    Drilling pattern and firing sequence.

    Large hole diameter is suggested to 89 mm with 2 large holes in the cut. The tunnel area is 59 m² and the number of blastholes is 82. Suitable explosives: ANFO or pumpable emulsion explosives of SSE (Site Sensitised Explosives) type in the cut and stoping holes. Walls and roof should be blasted carefully to avoid overbreak. Suitable explosives are 17 mm pipe charges or 40 – 80 gr/m detonating cord. With high efficient drilling equipment, loading of the blast should also be efficient to keep down the time of the work cycle. SSE explosives has the advantage of not being an explosive until it is pumped into the blasthole. The charge concentration may be changed in the hole so that no special explosive is needed in the contour holes. For efficient loading work with the SSE loading truck the service platform of the drill rig may be used together with the loading equipment of the SSE loading truck. Initiation system: Preferably a non-electric shock tube system.



    0 Not allowed!



  9. [19]
    alshangiti
    alshangiti غير متواجد حالياً

    مشرف وإستشاري هندسة المناجم


    الصورة الرمزية alshangiti


    تاريخ التسجيل: Mar 2007
    المشاركات: 1,472

    وسام مشرف متميز

    Thumbs Up
    Received: 89
    Given: 8
    ROCK BOLTS TYPE IN MINING AND TUNNELING
    in tunneling and underground mining, steel rod inserted in a hole
    drilled into the roof or walls of a rock formation to provide support to the roof or sides of the cavity. Rock bolt reinforcement can be used in any excavation geometry, is simple and quick to apply, and is relatively inexpensive. The installation can be fully mechanized. The length of the bolts and their spacing can be varied, depending on the reinforcement requirements.

    There are three major ways of anchoring the rock bolts: mechanical, grouted, and friction. The most common form of mechanically anchored rock bolt uses an expansion shell. A wedge attached to the bolt shank is pulled into a conical expansion shell as the bolt is rotated. This forces the shell to expand against the wall of the borehole. The two mechanisms by which the shell is anchored against the borehole wall are friction and interlock. A preload can be applied to the rock surface by tensioning the bolt with an attached hanger or face plate, which are designed to distribute the load uniformly onto the surrounding rock.
    The most common grout-anchored rock bolt is the fully grouted rebar, a threaded bar made of steel. Cement or resin is used as the grouting agent. A cable bolt is a reinforcing element made of steel wires in the form of a strand or rope; it is installed in the borehole with cement grout.
    Friction-anchored rock bolts represent the most recent development in rock reinforcement techniques. Frictional resistance to sliding is generated by a radial force against the borehole wall over the whole length of the bolt.

    0 Not allowed!



  10. [20]
    alshangiti
    alshangiti غير متواجد حالياً

    مشرف وإستشاري هندسة المناجم


    الصورة الرمزية alshangiti


    تاريخ التسجيل: Mar 2007
    المشاركات: 1,472

    وسام مشرف متميز

    Thumbs Up
    Received: 89
    Given: 8
    Friction Type Rock Bolts
    Split Set Bolts
    Roll formed steel tubing with a welded ring at the driving end. Installed in pre-drilled holes with the same rock drill. Ease of installation and low cost makes this a popular rock bolt.
    FRICTION BOLTS ARE AVAILABLE FROM PHQUniBar Bolt
    A fully threaded bar with superior tensile strength. Installed with either cement or polyester resin. Used for permanent installations. Cost of grout makes this bolt more expensive.
    NOT AVAILABLE FROM PHQDeformed Grouted Bar Bolts
    Installed with either cement or polyester resin. Ease of installation makes this a popular rock bolt. Cost of bolts and resins make these bolts more expensive than most.
    NOT AVAILABLE FROM PHQSling Type Eyebolt
    Bolt installed in a pre-drilled hole using a wedge (not shown) Used for the suspension of air and water columns, ventilation columns, electrical cables.
    NOT AVAILABLE FROM PHQShepherds Crook Bolt
    Installed in pre-drilled hole. This bolt provides effective support in areas prone to seismic events or high stress changes. Often used to hang pipe or cables.
    NOT AVAILABLE FROM PHQThreaded Rock Studs
    Installed with either cement or resin in pre-drilled holes This type of support is recommended for the short to medium term where long term stabilization is not planned.
    NOT AVAILABLE FROM PHQSwellex Bolts
    Installed in pre-drilled holes. Pushed into hole and inflated with high pressure fluid. Popular bolt due to ease of installation but more expensive than Friction Type Bolts.
    NOT AVAILABLE FROM PHQMechanical Anchor Bolts
    Expansion Shell Bolts
    Used in most Canadian mines. Installed in a pre-drilled hole using the same rock drill to torque up the nut on the bolt to proper tension. Low cost makes this a popular bolt.
    NOT AVAILABLE FROM PHQ

    0 Not allowed!



  
صفحة 2 من 3 الأولىالأولى 1 23 الأخيرةالأخيرة
الكلمات الدلالية لهذا الموضوع

عرض سحابة الكلمة الدلالية

RSS RSS 2.0 XML MAP HTML