Mineral Resources Eng

earthquake april 11th ,2012

2012-04-11T02:23:00.001-07:00

Earthquake Details

This event has been reviewed by a seismologist.

Magnitude	8.9 (Preliminary magnitude — update expected within 15 minutes)
Date-Time	Wednesday, April 11, 2012 at 08:38:30 UTC Wednesday, April 11, 2012 at 02:38:30 PM at epicenter
Location	2.043°N, 92.518°E
Depth	33 km (20.5 miles) set by location program
Region	OFF THE WEST COAST OF NORTHERN SUMATRA
Distances	495 km (308 miles) SW (219°) from Banda Aceh, Sumatra, Indonesia 1027 km (638 miles) W (263°) from KUALA LUMPUR, Malaysia
Location Uncertainty	Error estimate not available
Parameters	NST= 14, Nph=0, Dmin=0 km, Rmss=0 sec, Gp=198°, M-type="moment" magnitude from initial P wave (tsuboi method) (Mi/Mwp), Version=B
Source	NOAA Pacific Tsunami Warning Center
Event ID	pt12102000

Job interview tips

2012-04-09T15:38:00.000-07:00

Read the job description and company profile carefully so that you are aware of the job details when an employer calls you about your application. If the job advertisement does not contain enough information, ask the employer for more details.Remember to write down the name & contact number of the recruiter in case you need to call back later..Prepare for the interview by finding out more about the company, the job and the industry. Be punctual for your interview. Bring your resume, transcripts, certificates and relevant documents to the interview. IMPORTANT: If you cannot attend the confirmed interview for whatever reason, you must contact the employer at least one day beforehand to let them know..Keeping a good interview attendance record will help to ensure opportunities for interview in the future, as employers have the right to share their "No show" and late cancellation records..If you do not have the employer's contact details, look under the Company Profile in the Application Status page of your MyJobStreet account or look in the telephone book or Yellow Pages..Send the employer a Thank You email after the interview. 8.Follow up with the employer on the status of the interview after two or three days. This shows your interest for the job and may increase your chances of success.

TV

2010-09-05T13:58:00.001-07:00

Amethyist

2010-08-18T03:52:00.000-07:00

Bracelet Amethyist RM70 only

Tin Mining site

2010-08-18T03:49:00.000-07:00

Tin come from ore cassiterite

LANCHUTE(KERANDA MAYAT)

2010-08-18T03:45:00.000-07:00

PALONG

2010-08-18T03:40:00.000-07:00

Is the oldest method in mining seperation method,it used the speciic gravity of the mineral.the palong is design with slope 1:20 or 1:16.the heavy mineral will still in palong and the light mineral will running with water,tat had be supply

SHAKING TABLE(MEJA AYUN)

2010-08-18T03:34:00.000-07:00

SHAKING TABLE IS USES TO SEPERATE THE MINERAL AND GANGUE MNERAL,ACTUALLY IT USED WATER TO SEPERATE THE MINERAL,THE HEAVY PARTICLE WILL STUCK AT RIFFLE AND LIGHT PARTICLE WILL BE REMOVE AWAY

REGGETA HOTEL JAKARTA

2010-01-12T01:50:00.000-08:00

IMPORTANT ORE MINERALS

2009-11-06T11:30:00.000-08:00

Most elements need to be concentrated into amounts that can be economically mined from ore deposits (usually hundreds to thousands of times their crustal abundance). This concentration is usually accomplished by dissolution of the element by hot water (hydrothermal ore deposits - gold, silver, lead), preferential crystallization from magmas (chromite deposits or pegmatites), surface weathering and leaching (aluminum, nickel, copper), or gravity separation of minerals during erosion (gold, diamonds, titanium). In the majority of cases there are only one or two minerals that provide all of a particular element for commercial uses. Some elements in low concentrations (substituting in minor amounts for the major elements) are associated with minerals that are mined for other elements, but the shear volumes of materials that are processed result in a valuable byproduct (i e. elements associated with copper, lead, and zinc ores). Some elements are so valuable that almost any mineral containing that element in sufficient grades can be mined (gold, silver, platinum group).

ELEMENTS

Aluminum - The ore is mined from rocks that have been exposed to weathering in a tropical environment, bauxite. The main ore minerals in bauxite are gibbsite, bohmeite, and diaspore.

Antimony - The primary ore of antimony is it's sulfide, stibnite.

Arsenic - Recovered from other metal processing streams (primarily from the sulfosalts such as tennantite etc.). Arsenopyrite is the most common arsenic mineral. The relatively low demand for arsenic as compared to the amount of arsenic mined that is associated with other metals means it can be supplied from the waste streams of other ore processing.

Barium - The chief source of barium is barite with minor production of witherite.

Beryllium - The major ore mineral for beryllium in the U.S. is bertrandite while worldwide the major source is from pegmatites that contain beryl.

Bismuth - Primarily a byproduct of lead processing. Also found in a number of minerals such as bismuthinite and as a constituent in various sulfosalts.

Boron - Chief source is playa lake deposits of borax, colemanite, kernite, ulexite.

Bromine - Chief sources are brines from wells and Dead Sea.

Cadmium - Unlike many other commodities cadmium is produced as a byproduct of zinc (sphalerite) mining.

Cesium - The major ore mineral is pollucite, a pegmatite mineral. Production and use of this metal is extremely small (a few thousand kilograms per year).

Chlorine - Produced from the mineral halite (rock salt).

Chromium - The chief source is the mineral chromite which is found in large layered intrusives and serpentine bodies.

Cobalt - The primary minerals for cobalt is cobaltite. Some cobalt is also produced from weathered tropical orebodies.

Columbium (see Niobium)

Copper - Most copper ore bodies are mined from minerals created by weathering of the primary copper ore mineral chalcopyrite. Minerals in the enriched zone include chalcocite, bornite, djurleite. Minerals in the oxidized zones include malachite, azurite, chyrsocolla, cuprite, tenorite, native copper and brochantite.

Gallium - A byproduct of zinc and alumina processing. Some primary "ore" may contain up to 200 ppm. Ga.

Germanium - A byproduct of zinc ore processing. Also a deposit in China is associated with coal.

Gold - The primary mineral of gold is the native metal and electrum (a gold-silver alloy). Some tellurides are also important ore minerals such as calaverite, sylvanite, and petzite.

Hafnium - Primary ore mineral is zircon.

Indium - Primarily is a byproduct of zinc processing.

Iodine - Initial production was from seaweed. Iodine is extracted from natural gas field brines (up to 1200 ppm iodine in the brines).

Iron - Two major minerals in the production of iron are it's oxides, hematite and magnetite. These are found in preCambrian iron formations. Historically there was also production from goethite and siderite. The iron sulfides (pyrite and pyrrhotite) were not used as iron sources due to the difficulty of removing sulfur from the metals and the brittleness this sulfur caused in the metal.

Lead - The primary ore mineral for lead is it's sulfide - galena. Some minor production from the past has come from secondary lead minerals - cerussite and anglesite.

Lithium - The former primary ore minerals were pegmatite deposits of spodumene, lepidolite, and petalite, amblygonite. Currently the major U. S. production is from lithium carbonate brines.

Magnesium - Although magnesium is found in many minerals, only dolomite, magnesite, brucite, carnallite, and olivine are of commercial importance. Magnesium and other magnesium compounds are also produced from seawater, well and lake brines and bitterns.

Manganese - The primary ores are oxides/hydroxides of manganese which include minerals such as hausmannite, pyrolusite, braunite, manganite, etc. and the carbonate, rhodochrosite. A large potential source is the deep sea manganese nodules.

Mercury - The main ore is the sulfide, cinnabar.

Molybdenum - The primary ore mineral is molybdenite.

Nickel - The primary nickel ores are pentlandite, nickel bearing pyrrhotite and a weathering product, garnierite (a mixture of népouite, pecoraite and willemseite).

Niobium (Columbium) - The primary ore mineral is pyrochlore with minor columbite and tantalite-columbite.

Phosphorus - Main ore minerals are in the apatite group of minerals (hydroxylapatite, fluorapatite, chlorapatite).

Platinum group (Platinum, Osmium, Rhodium, Ruthenium, Palladium) - The primary ores are the native elements or alloys of the various elements or arsenides such as sperrylite. They tend to occur in layered intrusives associated with chromite deposits.

Potassium (potash) - The primary ore minerals are sylvite (primarily), brines, and langbeinite.

Rare Earth elements (cerium, dysprosium, erbium, europium, gadolinium, holmium, lanthanium, lutetium, neodymium, praseodymium, samarium, scandium, terbium, thulium, ytterbium, yttrium) The major ore minerals containing rare earth elements are bastnasite, monazite, and loparite and the lateritic ion-adsorption clays. Major U.S. production of bastnesite is from Mountain Pass, California.

Rhenium - Produced as a byproduct of molybdenite.

Rubidium - Substitutes for potassium in lepidolite and pollucite. Production is small (a few thousand kilograms per year).

Scandium (see Rare Earth)

Selenium - Recovered from copper processing.

Silicon - The primary source is quartz.

Silver - Silver production has been from the sulfide argentite/acanthite, native silver, sulfosalts such as pyrargyrite and proustite, chloride as cerargyrite. It is also found in small amounts in some tetrahedrites.

Sodium - Principle resources are halite (rock salt) or soda ash (see below).

Strontium - Main ore mineral is celestite, with minor production of strontianite.

Sulfur - Major production is from desulferizing natural gas and petroleum. Sulfuric acid is produced from the flue gases of metal smelters. Historically, sulfur was produced from native sulfur and pyrite.

Tantalum - Primarily from tantalite-columbite although minor amounts are found in tin concentrates.

Tellurium - Recovered in processing copper ores.

Thallium - Recovered from processing copper, lead and zinc ores.

Thorium - Recovered primarily from monazite.

Tin - Primary ore is cassiterite.

Titanium - Usually produced from placer deposits, the ore minerals are rutile, ilmenite, and leucoxene.

Tungsten - Primary ore minerals are scheelite and huebnerite-ferberite.

Uranium - The chief primary ore minerals are uraninite, pitchblende (a mixture of various oxides), coffinite and a host of secondary minerals such as carnotite and autunite.

Vanadium - Recovered from petroleum residues also produced from vanadium bearing magnetite rocks. In the past it was recovered from minerals in uranium deposits.

Zinc - The primary zinc ore mineral is sphalerite, zinc sulfide. Some past production has been from smithsonite and hemimorphite.

Zirconium - Major source is the mineral zircon.

INDUSTRIAL MINERALS

Abrasives, natural - Diamonds, garnets (almandine, pyrope and andradite), corundum (emery).

Barite - A major use for barite is as a weight increasing additive for drilling oil and gas wells.

Calcite - A major source for this mineral is limestone. It has been used for the manufacture of cement, application to agricultural lands for pH control, as a building material, and crushed for gravel.

Clays - Used in the manufacture of bricks, tiles and as a filler for paper etc.

Attapulgite
Ball Clay
Bentonite
Calcium Bentonite
Common Clay
*Minerals Fire Clay
Hectorite*
Kaolinite*
Meerschaum
Palygorskite*
Refractory Clay
Saponite*
Sepiolite*
Shale
Sodium Bentonite

Feldspars - Used in manufacture of glass, ceramics and enamels. Includes orthoclase, microcline, and albite (member of the plagioclase series).

Gemstones - The most valuable total gemstone production is diamond; corundum varieties, ruby and sapphire; beryl varieties emerald, aquamarine, and kunzite. Many other semiprecious gemstones are mined for decorative and jewelry use.

Gypsum - A major source for Portland cement, plaster of Paris, a soil conditioner, and an important component in drywall.

Perlite - Used in lightweight aggregates.

Soda Ash (sodium carbonate) - Primary production from trona, nahcolite and brines.

Zeolites - The primary natural production of zeolites include the minerals chabazite, clinoptilolite, and mordenite.

Miscellaneous mineral production - wollastonite, vermiculite, talc, pyrophyllite, graphite, kyanite, andalusite, muscovite, and phlogopite.

For more information see the United States Geological Survey website on mineral production (the source for most of this information).

--------------------------------------------------------------------------------
Copyright © 1997 - 2009 Mineralogical Society of America. All rights reserved

Uranium ore formation

2009-11-06T06:07:00.000-08:00

All ores are formed by geological processes. The clarke (Chapter 10) for uranium is about
4 mmol/mol (4 parts per million). Obviously, ore bodies have a higher concentration:
uraninite is 50 to 80% uranium, while davidite is only around 10% uranium. There are
roughly half dozen basic ore formation processes, of which the four most important for
uranium are:
1. sedimentary accumulation,
2. diagenesis,
3. magmatic segregation, and
4. hydrothermal circulation.
Sedimentation can occur in several ways. Limestone is formed by the rain of small marine
organisms onto the ocean bottom, and salt is formed when an interior sea dries up and is
covered by aolian deposits. In the case of gold, silver, uranium, and thorium, for example,
microscopic pieces could be carried off as runoff. In certain areas where the water stilled,
for example, a lake or widening of a stream, the denser pieces could fall to the lakebed or
streambed.
Diagenesis refers to chemical and physical changes that occur after deposition. If oxygen
is available, an element might combine with it to form an oxide. The oxide might replace
another compound, or, alternatively, if oxygen is removed, a sulfur atom could replace an
oxygen atom. Since the uranium-laced sediment might be covered by more sediment, it
could be subject to such chemical changes.
Magma is liquid rock. There could be ores formed by “freezing out” of materials by their
differing melting temperatures. The resulting ore bodies could rise or sink relative to the
Energy, Ch. 19, extension 4 Uranium ore formation 2
liquid depending on its density.
In hydrothermal circulation, hot water flowing can cause chemical changes and cause
migration of materials to help form ore bodies. This mechanism is less important for
uranium than for copper, silver, and gold ore formation.
Magmatic segregation is often involved in formation of uranium-rich rock. The uranium
may or may not be acted on by hot water (hydrothermal circulation) or hot gases during
its formation. In any case, volcanic action and other geological processes can cause regions
of uranium-bearing rock at concentrations higher then the clarke. As Earth’s plates move,
these original low-concentration rocks may be exposed and eroded by weathering. Water
can carry off the small pieces of rock, including uranium.
In the case of the Oklo deposit in Gabon,(29) not atypical of uranium ore formation, the
area that contained the ore that formed the natural reactor was originally a river delta.
When archaeobacteria began making the oxygen atmosphere, the exposed uranium became
oxidized. The oxidized uranium was weathered, traveled to the delta, and became encased
in the bottom ooze, where the uranium exchanged its oxygen for other elements. The
densest metals had accumulated in bottom sediments, and as these became overlain with
more sediments, the pressure eventually made sandstone out of the buried ooze.
The original volcanic rock containing low concentrations of uranium had become
sedimentary rock with higher concentrations. Geological processes compressed the
sandstone further, then uplifted and folded the rock. Water circulated among the broken
pieces of rock and helped the uranium gather in richer pockets. These were again overlain
and compressed, forming the ore body. This ore body was enriched compared to the
sandstone, and therefore greatly enriched compared to the original volcanic rock. It
Energy, Ch. 19, extension 4 Uranium ore formation 3
contained enough uranium (of course with high enough concentration of uranium-235) to
allow the natural Oklo reactor to run (see the box on this unique event in the chapter).
Uranium ore formations elsewhere also involved these four processes. Most ores seem to
be near regions that had experienced magmatic intrusions of volcanism in the distant past.
This is consistent with what happened in Oklo, Gabon.
Herndon argues that Earth contains an operating reactor. As radioactive decay decreases
the amount of uranium-235 relative to uranium-238, the reactor is going to turn off
eventually. He thinks that the georeactor runs Earth’s magnetic field.(30) In this case, if it
turns off sometime within the next several million years, it would have strong impacts on
Earth.

Properties and Classification

2009-11-06T05:55:00.000-08:00

Properties of the clays include plasticity, shrinkage under firing and under air drying, fineness of grain, color after firing, hardness, cohesion, and capacity of the surface to take decoration. On the basis of such qualities clays are variously divided into classes or groups; products are generally made from mixtures of clays and other substances. The purest clays are the china clays and kaolins. "Ball clay" is a name for a group of plastic, refractory (high-temperature) clays used with other clays to improve their plasticity and to increase their strength. Bentonites are clays composed of very fine particles derived usually from volcanic ash. They are composed chiefly of the hydrous magnesium-calcium-aluminum silicate called montmorillonite. See also fuller's earth.

Individual clay particles are always smaller than 0.004 mm. Clays often form colloidal suspensions when immersed in water, but the clay particles flocculate (clump) and settle quickly in saline water. Clays are easily molded into a form that they retain when dry, and they become hard and lose their plasticity when subjected to heat.

how clays formed

2009-11-06T05:21:00.001-08:00

Formation

Clays are divided into two classes: residual clay, found in the place of origin, and transported clay, also known as sedimentary clay, removed from the place of origin by an agent of erosion and deposited in a new and possibly distant position. Residual clays are most commonly formed by surface weathering, which gives rise to clay in three ways-by the chemical decomposition of rocks, such as granite, containing silica and alumina; by the solution of rocks, such as limestone, containing clayey impurities, which, being insoluble, are deposited as clay; and by the disintegration and solution of shale. One of the commonest processes of clay formation is the chemical decomposition of feldspar.

Clay consists of a sheet of interconnected silicates combined with a second sheetlike grouping of metallic atoms, oxygen, and hydroxyl, forming a two-layer mineral such as kaolinite. Sometimes the latter sheetlike structure is found sandwiched between two silica sheets, forming a three-layer mineral such as vermiculite. In the lithification process, compacted clay layers can be transformed into shale. Under the intense heat and pressure that may develop in the layers, the shale can be metamorphosed into slate.

list 5 main clay mineral

2009-11-06T05:08:00.001-08:00

Clay minerals include the following groups:

Kaolin group which includes the minerals kaolinite, dickite, halloysite and nacrite.[1]
Some sources include the serpentine group due to structural similarities (Bailey 1980).
Smectite group which includes dioctahedral smectites such as montmorillonite and nontronite and trioctahedral smectites for example saponite.[1]
Illite group which includes the clay-micas. Illite is the only common mineral.[1]
Chlorite group includes a wide variety of similar minerals with considerable chemical variation.[1]
Other 2:1 clay types exist such as sepiolite or attapulgite, clays with long water channels internal to their structure

list 5 main clay mineral

2009-11-06T05:08:00.000-08:00

Petroleum Enineering (rotary equipment and mud pump)

2009-08-24T08:41:00.000-07:00

Bauxite

2009-08-24T08:29:00.001-07:00

Bauxite

Mixture of Iron and Aluminium Hydroxides/Oxides
Al, Fe, O, OH

Bauxite does not require complex processing because most of the bauxite mined is of an acceptable grade or can be improved by a relatively simple and inexpensive process of removing clay.

The History Says
The first aluminum made in the US. was mined in Bartow and Floyd counties by the present Aluminum Company of America. A local man, Mr. Gibbons, operated these mines and also deposits in Arkansas, where the town near the deposits was named for him. He became a top official of Alcoa. The American Cyanamid Company mined bauxite to make alum. Large foreign deposits caused local mining to cease.

The Present Scenario
Exporting bauxite mines generated about US$1.4m in revenue per hectare mined in 1998 and a typical mine employed about 200 people for each million tonnes/year of bauxite produced or about 11 people per hectare.

--------------------------------------------------------------------------------

BAUXITE is a naturally occurring, heterogeneous material composed primarily of one or more aluminum hydroxide minerals, plus various mixtures of silica, iron oxide, titania, aluminosilicate, and other impurities in minor or trace amounts. The principal aluminum hydroxide minerals found in varying proportions with bauxites are gibbsite and the polymorphs boehmite and diaspore. Bauxites are typically classified according to their intended commercial application: abrasive, cement, chemical, metallurgical, refractory, etc. The bulk of world bauxite production (approximately 85%) is used as feed for the manufacture of alumina via a wet chemical caustic leach method commonly known as the Bayer process. Subsequently, the majority of the resulting alumina produced from this refining process is in turn employed as the feedstock for the production of aluminum metal by the electrolytic reduction of alumina in a molten bath of natural or synthetic cryolite (Na3AlF6), the Hall-Héroult process.

Formula
Al2O3 + SiO2 + TiO2 + Fe2O3

Typical Chemical Properties Available

Purities available from 98% (industrial grade) to 99.999% (high purity grade).

Typical Physical Properties Available

Physical properties vary widely according to the mine source. Granulations available include: 50 mm by down lumps, crushed coarse sizes (-3 mesh, -6 mesh, -8 mesh and -12 mesh) and ground powder sizes (-100 mesh, -200 mesh and -325 mesh).

Nominal Physical Constants:

Molecular Weight (g/mol.) -
Apparent Density (g/cm3) 3.08
Bulk Density (g/cm3) 3.1
Calcination Temperature(°C) 1650
Boiling Point (°C) -
Specific Surface Area (m2/g) -
Thermal Conductivity (cal/s-cm-°C) -
Mohs Hardness @20°C -
Specific Gravity 2.45- 3.25
Apparent Porosity (%) 8.4
L.O.I. (%) 0.1

Bauxite Mining in Forest Areas
The conservation of rain forests is a key concern often voiced with regard to bauxite mining. Only about 6 % of the world's bauxite mining is today conducted in rain forest regions, affecting a total area of around 1.5 km2 per year. The total area of the globe currently covered by rain forest is about 18 million km2. The original flora and fauna of much of the land involved in bauxite mining is restored once mining operations have ceased. For all forest areas used for bauxite mining, 80% is returned to native forests, the rest is replaced by agriculture, commercial forest, or recreational area, thereby making the area more productive for the local community. As far as rain forests in particular are concerned, however, the area used for bauxite mining in rain forests is almost totally reverted back to rain forest.

Bauxite mining
There are numerous bauxite deposits, mainly in the tropical and subtropical regions, but also in Europe. Bauxite is generally extracted by open cast mining from strata, typically some 4-6 metres thick under a shallow covering of topsoil and vegetation. In most cases the topsoil is removed and stored.

Exporting bauxite mines generated about US$1.4m in revenue per hectare mined in 1998 and a typical mine employed about 200 people for each million tonnes/year of bauxite produced or about 11 people per hectare. Usually mines offer relatively well-paid jobs and mining companies tend to provide assistance to their neighbouring communities.

There are attractive commercial and social reasons for the development of a bauxite mine. The mining company wants the ore to use or sell while the local inhabitants want the mine for employment and for the community assistance that the mining company usually offers. National governments want the development for these social reasons and also for the revenue provided by a mining company.

These social benefits are complemented, according to the International Aluminium Institute's latest "Bauxite Mine Rehabilitation Survey", by the mining companies' increasing awareness of environmental factors. Mined areas are being restored to an environmentally stable condition: 92.7% of surveyed operations have formal, written rehabilitation procedures in place. A total of 282km2 (28,245 ha) of land has been rehabilitated to date at 22 operations.

Our survey shows that increasingly mining companies are concerned about environmental matters. Bauxite mining is accompanied by land rehabilitation and environmental control to restore the area to a desirable environmentally friendly condition. It is possible for everyone to gain from mining activities.

Bauxite mining method
Eighty percent of world bauxite production, mainly from large blanket type deposits is from surface mines, with the rest, mainly from Southern Europe and Hungary, from underground excavations. On some surface deposits there is no overburden, and on others, the bauxite may be covered by 70 metres or more of rock and clay. Deposits that are hardened may require blasting in order to release the ore. Once the bauxite is loosened into manageable pieces it is generally loaded into trucks or railroad cars and transported to crushing or washing plants or to stockpiles. Underground bauxite mines are used to exploit pockets or beds of deposit between layers of carbonic rock. Water in flow is a problem in most underground operations and dewatering shafts are often drilled before mining begins.

Unlike the base metal ores, bauxite does not require complex processing because most of the bauxite mined is of an acceptable grade or can be improved by a relatively simple and inexpensive process of removing clay. In many bauxites, clay is removed by some combination of washing, wet screening and cycloning, even by hand picking or sorting.

Traditional uses of bauxite

Blast Furnaces
Iron/Steel Ladles
Torpedo Cars
Electric Arc furnaces
Tundishes
Soaking Pits
Reheat/Soaking Pits
Open Hearth
Cement
Aluminum
World Bauxite Mine Production, Reserves, and Reserve Base
(x1000 tonne)
Mine production Reserves Reserve base
2000 2001

Australia 53,800 53,500 3,800,000 7,400,000
Brazil 14,000 14,000 3,900,000 4,900,000
China 9,000 9,200 720,000 2,000,000
Guinea 15,000 15,000 7,400,000 8,600,000
Guyana 2,400 2,000 700,000 900,000
India 7,370 8,000 770,000 1,400,000
Jamaica 11,100 13,000 2,000,000 2,500,000
Russia 4,200 4,000 200,000 250,000
Suriname 3,610 4,000 580,000 600,000
United States NA NA 20,000 40,000
Venezuela 4,200 4,400 320,000 350,000
Other countries 10,800 10,200 4,100,000 4,700,000
World total (rounded) 135,000 137,000 24,000,000 34,000,000

The Major Producers
China
Today, exportable refractory-grade bauxite (essentially all diasporitic) is mined mainly from two provinces in China-Shanxi and Guizhou. Shanxi reportedly exports two-thirds of the total.

The Guizhou and Shanxi materials have similar characteristics, however, Guizhou has the disadvantage of higher TiO2 (3.7% typical vs. 4.2) and alkalies (0.2% typical vs. 0.6).

Although there have been unconfirmed reports of higher bulk densities in Guizhou, the two provinces are essentially the same in principle, with Shanxi possibly having the edge. In this case, chemistry is a minor influencing factor (lower alkali content, higher Al2O3 in Southern Shanxi), meaning bulk densities in China are primarily a function of the calcining equipment and process.

With residence time as a primary factor, their minimum control rudimentary shaft kilns are limited to maximum range BSGs (3.20-3.25). Rotary kilns can produce up to the 3.30 range and the Chinese round kilns can produce up to 3.35 by means of a special 18th century burning procedure.

It is estimated that 50% of Chinese refractory-grade bauxite is produced in updraft shaft kilns, with the remainder split between round and rotary.

The Chinese bauxite supply picture is complicated because there are ~300 bauxite mines in China, with the exported product rarely representing a single mine source. When ISO-9000 comes to refractory-grade bauxite in China, it will be with some difficulty.

The supply of Chinese refractory-grade bauxite has improved during the past 20 years-in part due to the installation of several controlled processing plants in Tianjin. However, the basic supply from the mine to the kiln to the port still involves considerable rudimentary control and consequent quality variations. This could improve significantly if experienced third parties get involved in the mining and calcining of the material.

Despite numerous complaints that the Chinese producers have been dumping, it does not appear to be probable. In any case, recent export and provincial taxes will now force the Chinese prices somewhat closer to world market levels. This will tend to promote a switch back to South American bauxites.

Refractory-grade bauxite also is used to produce brown-fused alumina, a significant product in China. Total current production there is reportedly in excess of 300,000 tpy.

Brazil
The MSL Minerais (CAEMI) operation is the new supplier on the block. Despite some apparent built-in disadvantages, it has managed to develop a niche market and justify the installation of a second rotary kiln in 1994. Thus, increasing total productive capacity to ~140,000 tpy.

Although the bauxite vein at CAEMI is only 1-3 m thick, the relatively 8-12 m thick overburden is within an acceptable proportion. Therefore, mining costs should be relatively low. The crude ore must be beneficiated, first by crushing (10 mm maximum) washing and screening, then with a heavy media process to remove iron. After calcining, the material goes through eight iron-removing magnetic separators. Despite the relatively high SiO2 content (approaching 10%), the beneficiation costs and relatively higher fuel costs for calcining, the finished product is priced lower than Guyana RASC, and has gained significant market share-particularly in Europe.

The higher SiO2 and lower alkalies in the MSL bauxite, together with a uniform fine kiln feed size, contributes to the higher level of mullite (and lower corundum) in the final product. TiO2 is a low 2.2%, tielite a low 0-2%.

Guyana
Bauxite was first identified in Guyana in the period 1897-1910. Although Alcoa Industrial Chemicals began alumina-grade bauxite production in Guyana in 1917, and Alcan took over in 1929, it was not until 1938 that refractory-grade bauxite was separately identified and produced. The typical processing of Guyanese bauxite is straightforward: Bauxite is crushed to -9 cm, washed and screened, crushed to -4 cm, rewashed, then rotary kiln calcined, with some final de-ironing before shipment.

Refractory-grade bauxite from Guyana presently falls into two separate geographic sourcings: the original Linmines' home of the traditional world standard RASC bauxite; and the Berbice/Bermine operation, the latter primarily a source of abrasive- and chemical-grade bauxite.

Reserves at Linmines are substantial. Ongoing improvements to operating practices and costs began five years ago, with the consequent gradual improvement to a global competitive marketing position.

A privatization program now in progress in Guyana should contribute to an improved bauxite product, availability and costs.

Ore geology and industrial minerals ... - Google Books

2009-08-19T06:24:00.000-07:00

Ore geology and industrial minerals ... - Google Books

Diamond

2009-08-09T10:46:00.000-07:00

Diamond: not necessarily colourless

Broadband speed meter

2009-08-09T10:29:00.000-07:00

Klu nk tau speed internet yang anda guna,try this!

Picture Sapphires

2009-08-09T10:24:00.000-07:00

Sapphires are found in India, Burma, Ceylon, Thailand, Vietnam, Australia, Brazil and Africa. Yang terbaru dijumpai kat dlam jam tgan roscani Dr Kamar

Picture kunzite

2009-08-09T10:20:00.000-07:00

Mainly found in Afghanistan, Madagascar, Brazil and the USA

Picture lapis lazuli

2009-08-09T10:13:00.000-07:00

Hanya boleh dijumpai di afghanistan...salah satu sebab us serang afghanistan

explaration guidelines

2009-08-09T09:12:00.000-07:00

Exploration (Prospecting) Guidelines

Chromite deposits
Nickel-copper deposits
Platinum deposits

Chromite Deposits

Stratiform:

1.Identify well layered mafic-ultramafic intrusions;

2.Prospect below the mafic cumulate portions of the intrusions (i.e. below the portion which is completely gabbroic).

Podiform:

1.Carefully prospect within all dunitic portions of Alpine-type peridotites (Harzburgite-Dunite components of ophiolite complexes).

Ni-Cu Deposits

1.Prospect in the lowermost portion of layered and not so well layered mefic-ultramafic intrusions (both cratonic and synorogenic), komatiitic flows and sills;

2.Pay special attention to embayments in basal contacts.

PGM Deposit

1.Identify layered mafic-ultramafic intrusions and differentiated sills (possibly cratonic);

2.Sample any sulphide-bearing material, especially if carrying visible pyrrhotite-chalcopyrite mineralization;

3.If prospecting for Merenski-type occurrences, look for very thin (1 m) but laterally persistent disseminated sulphide-bearing horizons within complexly interlayered peridotite-pyroxenite-troctolite-anorthosite and gabbro sequences;

4.Look for sulphide-bearing material near contact zones of mafic-ultramafic complexes composed of several intrusive phases;

5.Look for unusual textures and mineralogy. Namely look for pegmatitic textures and development of hydrous minerals within layers or massive units that are normally of even grain size and anhydrous;

6.Investigate the drainage of Alaskan-type intrustions for potentially significant Pt placers.

Unit that relate to mineral/metal/gemstone

2009-08-09T02:38:00.000-07:00

1lb(paun)=453.59237g
1oz(ounze)=28.3495231g
1ppm=0.000000999kg/l
1troy oz=31.1034768g