Showing posts with label SCIENCE OF MINING. Show all posts
Showing posts with label SCIENCE OF MINING. Show all posts

Precious Metals Analysis For Sampling

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A true sample is a small sample of a mask which represents the average composition of the mass or simply stated truly representative of the bulk, uniformity of composition and particle size of the boat material are the key features which lead to selecting the processes required to generate true samples.

Both lots of materials for saddling come in many forms from mick solids like crushed or for scraps circuit boards for recycling to sludge slurries and solutions from industrial processes.

To maximize uniformity of composition fault materials are most often process prior to sampling.

For example scrap metal lots are melted to form alloys for leech to take all the metals into solution for analysis. When the ball contains solid particles imaginas ation for mechanical mixing is a sampling technique employee to create a uniform distribution of particles so that each sample taken from the mixed will represent the average composition.

The uniformity of composition of the starting material greatly affects the amount of reduction needed for true sample

Highly uniform materials require less reduction. fundamental principle of good sampling is to gradually reduce the bulk simultaneously with a gradual reduction in the size of the particles.

Larger sample sizes are required with larger particle size distributions of the bulk. Therefore it is of great value to crush and grind the sample to allow for taking smaller reliable sample. The sample is then mixed thoroughly to obtain a mixture that is homogenized.

For example when salt is completely dissolved into a solution, the solution is thoroughly mixed so that any droplet will contain the same concentration of dissolved salt. in order to get the same amount of thorough mixing with solid particle mixtures, the solid particles must be ground small enough and extensively mixed prior to sampling.

Each type of material for sampling and analysis has optimum ratios for the finest relative to the size of the sample. These ratios must be determined experimentally. middle of the blended and split test samples are taken from lots and sent for analysis.

Essay samples are then taken from the test samples which typically require further grinding and splitting. there are a number of traps that can produce misleading results that karen handling should avoid.

cross-contamination for one sample to the next could occur if sampling equipment is not cleaned adequately between life. care must be taken to collect all of exhaustion crushing grinding or handling fine materials that some does have different metal concentrations than the bone.

Fine particles may also pick up or lose moisture while passing through sampling equipment although they may not appear wet they may contain enough moisture to affect results so this should be accountable.

When samples reach the essay lab they may have segregated so the test sample should also be blended again and split properly.

The ipmi recognizes the importance of this technology to the precious metals community and has published and made available several books on this subject. The sampling and analysis committee of the ipmi also publishes guidelines in this field

Video Precious Metals Analysis For Sampling

The Basics Sampling Science for Precious Metals Analysis

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The process of taking small samples for analysis
The process of taking small samples for analysis to determine the precious metal content of a large quantity of material is the most critical. Small errors and sapling can there fore lead to large differences in the calculated value of each precious metal. Sampling science and techniques are used on primary sources of precious metals from ore samples at mine sites.

Due to the high value of precious metals very low concentrations are contained enviable primary or secondary sources. For example a platinum concentration as low as 2 to 3 grams per ton of ore or scrap material is often profitable to recover and refine.

The process of taking samples from drilling to analysis
Secondary sources of precious metals which are manufacturing scrap or end-of-life materials for recycling and  refining must also be sampled properly for accurate results.

The fundamental processes include preparation, homogenization, equation handling and splitting from bulk lots to prepare a small sample to represent the average composition of the large amount of material.

Homogenizing is the process by which the material is blended uniformly to facilitate accurate sampling. Splitting is the act of evenly dividing materials while avoiding any separation or segregation for example a typical sample size of 300 grams may be selected to represent the average composition of several tons of material once the 300 grand sample is sent to the analytical lab the sample will then be further split to obtain smaller samples used for analysis.

Homogenizing process

The science and techniques used at mine sites for obtaining or samples utilize complex statistical analysis. The same material from initial surface exploration is first panel sighs to determine locations for drilling core samples to map out or deposits and determine mind valuations.

Chip samples are also taken within an active mind. Evaluation or deposits are used to determine where to drill and to calculate the value of the ore which is required to secure financing for the mining operation.

Materials that contain precious metals for recycling and refining are collected in bulk lots it is critical to accurately determine what concentrations of each precious metal are contained in each lot for two reasons.

First is to obtain the technical information needed to determine which processes to use for refining or whether it is even worth the cost of refining.

The second is the financial consideration to place the correct value on each lot as the materials change hands from suppliers to fires. Samples are often analyzed by both parties and transactions with a third sample saved as a referee sample for possible analysis by an independent lab.

Video The Basics Sampling Science for Precious Metals Analysis


See Also :
Precious Metals Analysis For Sampling

Hydrometallurgy For Gold Leaching

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Refiners hydrometallurgy will give examples of careers and precious metals using chemistry both inorganic and organic, chemical engineering, metallurgical engineering and others. Hydrometallurgy for gold refers the processing techniques that require wet chemistry approaches to separate the precious metals from the surrounding materials vs pyrometallurgy which requires heating and smelting operations to perform the separation.

Hydrometallurgy to take many forms depending on the substrate or the material which contains the precious metals. Many of these chemicals used are very hazardous and these processes should only be done by professional refiners

Hydrometallurgy is an extractive metallurgy process using aqueous solutions to recover metals it involves technologies with solubilize, concentrate and then recover specific metals.

For example a first step maybe to chemically dissolve or leach a material to eventually extract metals by means of precipitation or electrically reducing the metals.  Leaching is the first process used to extract metals into an aqueous solution, chemical acids or alkali eyes are used to convert metals into soluble salts within the solution.

For example aqua regia is a highly corrosive acid mixture of nitric and hydrochloric acids which will dissolve most metals, including gold platinum and paladium

In the other platinum group metals however do not dissolve in aqua regia so it can be used to separate these groups, all those silver also dissolves in aqua regia it immediately precipitates to silver chloride so does not go in the solution. Nitric acid alone is used to dissolve silver.

The different gold leaching processes are descriptively named :

Gold leaching processe
1. Situ Leaching
 In situ leaching also called  solution mining. Extrating the minerals directly from ore in the mining. Leach solutions are pumped through the ore to surface.  In situ leaching is occasionally used in select mining operations to leach precious metals from surrounding rock structures.

2. Heap leaching is routinely used to remove gold from ore deposits in tailings

3.Vat leaching is most frequently used when removing gold from secondary scrap materials such as electronic scrap or even jewelry scrap

See Also : 
How To Work The Heap Leaching Mining  
Gold Leaching Process With Carbon In Pulp

4. Agitated leaching is where the material is saved in slurry with the extracting solution.

5. Pressure leaching places the material, solvent along autoclaves to pressurize heat, it is also used when gases need to be added for the leaching reaction.

The pressure oxidation process the free gold is an example of this cyanidation and chlorination are other pressure leaching processes, after leaching solution concentration and purification steps are employed to further concentrate and separate the precious metals

These refining processes can be used for precious metals extracted from primary remaining sources as well as secondary sources of industrial or recycle scrap materials

Video How To Refine Precious Metals - Hydrometallurgy

Gold Technology Carbon In Leach From Curtin University

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Technology Carbon In Leach
Curtin University’s Gold Technology Grouph as designed and developed an automated “Carbon Meter" to continuously, reliably and accurately measure carbon concentrations in CIL tanks.

Currently, measuring the carbon to slurryratio involves taking a small sample from the tank, it’s time-consuming and has drawbacks interms of frequency, accuracy, and repeatability.

To optimising this process, you must precisely control the ratio of activated carbon to slurry.

Simply put, too much carbon is inefficient, while too little allows dissolved gold tobe lost to tailings.

But to control it, you first have to measure it. And this is true for the Carbon In Leachor CIL gold extraction process. Carbon-in-Leach accounts for about 75% of the world’s gold production.
Process Carbon In Leach
In this process, ground, gold-bearing ore is dissolved in a chemical slurry. Granules of activated carbon are added to absorb the dissolved gold, before further processing.
This robust, self-contained unit takes sample sup to 20 times larger than the manual method, every 15 minutes, 24 hours per day, whichit feeds into a measurement cylinder that strains the larger carbon particles from the slurry before a laser beam accurately measures the amount of captured carbon.

This data, along with the well-established SIMCIL modelling tool, is used to optimise carbon management to a degree not previously possible.

The end result is less soluble gold lost to tailings. Gold producers are processing higher tonnages of lower grades of ore than ever before.

And along with fluctuating gold prices and increased costs, optimising processes is the key tolong-term profitability.

For many CIL operations, optimisations resulting in recovery a 100th of a gram more gold per tonne of slurry processed, can increase annual revenue by millions of dollars. And this is a significant benefit for any mining operation.
Activated  Carbon for Carbon In Leach
Video Gold Technology Carbon In Leach From Curtin University

Gold and Cadmium

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Gold is a precious metal. This metal is liked by all people world wide. Recently the rate of gold has been rising up steadily and the prices of other commodities is calculated according to the rate of this yellow metal. Countries trade with one another, paying in the form of gold. Of all the trophies given in games, competition,and other activities, gold has the first place. Ornaments takes the first place in marriages. It is a solid asset which has liquidity, and helps at hard times.

What makes this gold metal valuable?

Its glittering yellow colour never fades, just as its value. Gold has flexibility and can be treated to thin sheets or wires. It is mined from the hidden rocks found underneath, and the cost for processing the metal is time consuming and very costly.

Golden bars or coins are otherwise called as Bullion. Bullion are mined by certain countries and sold in the world market. Bullion are pure gold which is 24carat. 99.9% purity is common. It is not possible to make ornaments out of 24 carat gold bullion.

24 carat gold is lessened to 22 carat and thus transformed into jewels. 24 carat is a mixture of copper and silver metals. these metals are combined in 2:1 ratio. the carat rate and value of gold decreases if the metals are added more.

Cadmium

Cadmium is a metal. This metal is mixed with gold to make ornaments and is considered to be pure. The world gold council has a hallmark for pure gold. With the addition of cadmium it is named as 916kdm. Cadmium added gold is considered pure because the cadmium added jewels when reheated or beaten up nothing is lost, and the result we get is pure gold.

When 916 kdm gold is heated,the Cadmium metal evaporates into the thin air in the form of gas. This gas is toxic.cadmium content gold does no harm to the wearer. 916 kdm purchased gold has a resale value, if it is bought as an asset.

Purchasing of gold is a very good mode of asset and its value increases day by day, so the craze for gold never fades as its value and colour,so it is necessary to know the relation between gold and cadmium. All that glitters are gold, and the value of this asset increases, only if the correct ratio of silver and copper are added.

Cadmium - Periodic Table of Videos 

Different Types Of Mining Processes

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Mining has become a controversial industry because of its “devastating” effect to the environment and the ecosystem. However, it has contributed so much to civilization that without it, we could never be where we are today in many aspects.

There are two basic methods of mining. These are the surface and the underground mining processes:

1. Surface Mining

This involves the mining of minerals located at or near the surface of the earth. This encompasses at least six processes and these are:

• Strip Mining – this involves the stripping of the earth’s surface by heavy machinery. This method is generally targeted at extracting coal or sedimentary rocks that lay near the earth’s surface.

• Placer Mining – this involves the extraction of sediments in sand or gravel. It is a simple, old-fashioned way of mining. This method is generally applicable to gold and precious gems that are carried by the flow of water.

• Mountain Top Mining – this is a new method which involves blasting of a mountain top to expose coal deposits that lie underneath the mountain crest.

• Hydraulic Mining – this is an obsolete method that involves jetting the side of a mountain or hill with high pressure water to expose gold and other precious metals.

• Dredging – it involves the removal of rocks, sand and silt underneath a body of water to expose the minerals.

Open   Pit  – this is the most common  mining  method. It involves the removal of the top layers of soil in search for gold or buried treasure. The miner digs deeper and deeper until a large,  open-pit  is created.

2. Underground Mining


This is the process in which a tunnel is made into the earth to find the mineral ore. The mining operation is usually performed with the use of underground mining equipment. Underground mining is done through the following methods:

• Slope Mining – it involves the creation of slopes into the ground in order to reach the ore or mineral deposit. This process is generally applied in coal mining.

• Hard rock – this method uses dynamite or giant drills to create large, deep tunnels. The miners support the tunnels with pillars to prevent them from collapsing. This is a large-scale mining process and is usually applied in the extraction of large copper, tin, lead, gold or silver deposits.

• Drift mining – this method is applicable only when the target mineral is accessible from the side of a mountain. It involves the creation of a tunnel that’s slightly lower than the target mineral. The gravity makes the deposit fall to the tunnel where miners can collect them.

• Shaft method – this involves the creation of a vertical passageway that goes deep down underground where the deposit is located. Because of the depth, miners are brought in and out of the  pit  with elevators.

• Borehole method – this involves the use of a large drill and high pressure water to eject the target mineral.

These are the basic methods used in the extraction of common minerals. There are more complex systems, but still, they are based on these fundamental processes.


Source Of Gold Ores

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Gold and silver metals are obtained from a variety of different types of rock ores. Most people think of gold nuggets constitute the source of the gold. But the reality is very few gold derived from the nugget. Nearly all newly mined gold comes from ores from natural hard rock mining, fine gold grains, even microscopic particles. 

Gold widely found in nature, although it is one of rare metals. It often happens gold which known as the native metal encased within a mineral such as quartz. And historically gold the most productive, occur in the vein deposits. Currently these widespread deposits give much of the world gold ore

The element gold ores in nature occurs even mainly in the form of native gold, In various gold ores, original gold mineral content commonly occurs, fine mineral particles and small contained within sulfide minerals such as pyrite.

Iron pyrites a very common mineral associated with gold, but it also serves as a reducing agent. Therefore, if gold is found enclosed in pyrite, it is always free gold and not as some kind of gold sulfide. Gold also sometimes in chalcopyrite, galena and arsenopyrite and stibnite, but not as one is found in such quantities as may be found in pyrite. Other minerals such as sphalerite, pyrhotite, magnetite and hematite sometimes carry little amounts of gold as well. 

Gold also comes as Telluride as Calaverit. Common gangue in gold ores include quartz, fluorite, calcite and pyrite, but many others can be found in smaller amounts

Gold Ore Minerals :

The most prominent is pure gold – The most common the native gold contains a Little amount of silver, copper, platinum, etc. 

Telluride minerals are the most common minerals that significant gold in their makeup. These include:
  • Petzite (Ag, Au) 2, Te,
  • Hessit (Ag2Te)
  • sylvanite (Au, Ag) Te2
  • Calaverit (Au, Ag) Te2
  • Krennerit (Ag2Te, Au2Te3)
  • Nagyagit ( Au2, Pbi4, Sb 3, TE7, S7). 
The gold containing sulphides and tellurides, are primary formation from gold ore, although auriferous chalcopyrite could be formed by secondary enrichment process.

Native gold can occur in the primary, secondary enrichment or oxidized zones. The tellurides, which are usually associated with pyrite, are widely used, though not so often, but not always recognized; in fact, some of the miners they are mistaken for sulfides  

Common types of gold ores

Gold deposits are often classified according to their association. 

1. Of these can be cataloged as quartzose.

This means that the gangue mineral is acid, that is, quartz and fluorite which may be very abundant or the other gangue minerals of the alkaline soil group. Not infrequently, it seems varies pyrite and limited amounts of chalcopyrite and galena within quartz quantities. These are free milling ores.

Through a free milling ore it is meant that the rock does not require roasting before the gold can be recovered therefrom. Dry ore is the term that is often used for this category. 

2. Copper ores containing gold ore mineral

These are widely used in the United States and much of the chalcopyrite is gold bearing. This auriferous copper ores are particularly abundant in Colorado, Utah, Montana and British Columbia. They are also in Gold Hill, North Carolina and in Canada to Newfoundland. 

3. The class of gold ore is auriferous lead ores.

The proportion of lead in these rocks is large and the gold content is often low. They are refractory ores such as copper ore. The refractory ore is a meant requires roasting before extraction processing. The heavy sulphides as copper, lead and antimony require this method of treatment, that is the condition of the gold in the mineral will not allow of its immediate capture with most recovery systems.

4. gold ores comprises the gold-telluride group

The gold telluride ores occur accompanied by other tellurides with silver, lead and antimony or as native gold accompanied by other tellurides.  These ores are often sent directly for the treatment of smelters. 

5. Type of disseminated ore.

They are often low in grade, but present in very large numbers. They fill large fracture and fault zones or replace certain geologic horizons. They are the result of the circulation of large amounts of heated water deep underground.


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Drill Testing To Sample Gold Deposits

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Test process drilling for gold is an important step in the every prospecting and gold mining industry. Test drilling is a step that is used continuously to obtain samples of bedrock in the land of gold mining project. The sample is then tested to determine whether it is gold in the project area in mining and to estimate the amount of gold that can be mined in the area. 

In the process of drilling testing can produce a variety of results sample, because each gap can occur various kinds of different types of rocks and soils, The process of drilling test is a step that most highly effective to get the test results of rock in the ground in estimating the amount of gold ore deposits in the area which will do the mining.

Drilling is an absolute necessity to assess metal ores prior to the process of exploitation in an extensive mining operation. Drilling can be done for all large-scale mining, before the open pit mine development, or for the assessment of large commercial placer mines. 

Preliminary Prospecting Works In Test Drilling

Before test drilling for gold, there are several steps that can be done early, it is made to prospecting works. Often the area to test can bushes, hard terrain or other obstacles drilled, which may influence the outcome of exploratory drilling. It is important, therefore, it will be handled first.

One step that can be used is by ridding the area which will be conducted test drilling. This can help reduce the amount of land the ground which will done testing on drilling,thus support and make to be effective the test holes are drilled. 

Drill testing

In the process of test drilling in gold mining is intended to determine whether the area has gold potential which can be used for large-scale mining.This is very helpful in determining the amount of gold deposits
and grade gold contained in the soil in the area that will be in mine.

Test drilling can also specify the information that is significant of the general geology of the rock structures that exist in the soil at the prospect area, the geochemical structure and other information from other minerals besides gold deposits existing in the test drilling area 

The pattern of test holes, the distance and the number of test wells is mineral determined by the geometrical alignment of the drill, the geochemical composition of the area and the distribution of the target.

For most in scale test drilling in mining area is often gridded out into small grids that can determine the number of holes to be drilled. Sometimes in the drilling process is done in a manner soil formation such as rifts, ditches, river basins or even valleys. 

In most of the tests for the drilling of gold speed and cost are important factors that are considered by geologists.

If in the process the first step is successful, then to get a drilling method that is more accurate in determining the mineral content of gold or may be in the process of the most extensive can be implemented

Some of the methods most commonly used test holes, you can use includes hand drilling, rotary drilling, percussion drilling and diamond drilling. 

The significance of the test drilling for gold

test drilling is to enhance the importance of prospecting before a mining operation, and drill testing is one of the methods most commonly used for sampling.

Albeit with very expensive, it takes some of the risk and guesswork out of the mining process and an estimate of how much gold there is in the area

The type of drilling specifies the device to be used. 

Hand Drilling

This is carried out in at a little place for little operations. Hand drilling done by using a manual hand, the phase required prior training stage, as sample tubes and augers. These drills can not penetrate bedrock and thus limited in its application entirely.

Variety of hand drilling tools can be used for hand drilling, but hand test can only for little gold mining drilling.The advantage of the hard drilling reduced cost of major methods, and this may be the best method for individual miners who lack the resources for greater exploration.

 Percussion Drilling

This type test drilling where the drilling equipment can be used to enter into the bedrock up to a depth of approximately 10 meters. Percussion drilling is drilling that uses compressed air drilling equipment, this makes lebihh far stronger than using a hand drill.There is also drilling using large air drilling equipment ,which can be used in complex drilling in the mining area.

Rotary Drilling

Rotary drilling is drilling relatively expensive yet very easy to use in a variety of conditions. In the drilling process using a ring and an air compressor in the process of drilling holes to be tested. With the true tools and skilled workers, this type of exploratory drilling takes the least time of all available drills. The drill may obtain samples from between 20 and 100 foot holes. 

Diamond Drilling

This is the most versatile drill testing method that can use. The machines used for this type of drilling gets superior most samples since it can drill deep and at a certain angle and conditions.

In most cases, drills are used herein, can be powered by electric engines, gasoline, diesel, and even air. However, the process can only slow and very expensive in practice and thus it is used only for complex projects that require extensive drilling.

This Video  from Hellix Ventures Inc. - Margarita Gold Drill Program

Gold In Quart ( Video )

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Natural gold in quartz samples are crystalline gold nuggets constitute gold that are still attached in host rock which is typically made of quartz. Gold in quartz is the result of hard rock mining, where gold veins apart the gold-laden exposing the gold laden quartz within the vein.
Gold veins that are so wealthy in gold which can be seen with the naked eyes is visible are very rare, and veins so wealthy that they produce the kind of natural gold in quartz samples. In epithermal gold deposits, it is quite common for significant gold veins running through quartz rock, and these samples can be found with a high quality metal detector. 

Often quartz samples these gold are very beautiful and interesting, so they are greatly appreciated by mineral collectors, sometimes even more than the value of gold itself.

With sample-grade gold such as this, it is recommended that looking for gold collectors who pay a premium for them rather than crushing these mineral samples. However, there are occasions when it is the best interest of the prospectors to destroy these pieces of ore. 

The first discovery of gold in quartz appears from a man named Davidson, a Baptist preacher, in February 1851,on the south side of Amador creek near the spring then used by the miners. Boulders of great size were lying on top of the Soil

The intelligent men who worked while gold rush in the canyons and rivers in the early days, they found gold in the gravels. Sometimes gold was found with quartz adhering. The quartz veins lining the hills near the richest placer, also served on this rock demonstrate as the original source of the gold. In Carson Hill, and then Mariposa County, quartz found immensely wealthy, but the expense of blasting the rock out  and crushing, so that no serious attempts were made until 1851. 

The whole California gold country swarming with quartz; in some places in mountains, which had filled the ravines with broken quartz, but not all the quartz had gold in it. The miners to found gold in quart with the hard way, until some experienced men were put on many locations.

VIDEO QUARTZ VEIN GOLD ORE SPECIMEN ~ FROM GOLD MINE

Semi Autogenous Grinding Mill In Mining ( SAG Mill Video )

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SAG mill in the mining constitute equipment used in the mining industry for grinding material, it uses steel balls next to large rocks to grind. SAG is an acronym for Semi Autogenous Grinding Mill and the SAG mills use minimum ball charge 6-15%. It has a large diameter and short length in the equipment SAG. 

The liner is made of wear-resistant steel and provided with lifters, which when the mill rotates can in increasing the load support. The load consists of dry ore, steel balls and water, which occupies 30% of the volume. 8% of this volume is steel balls. 

A SAG mill is most common used in the mining areas, especially in the mining of precious metals,  such as gold, copper, silver and nickel. The SAG mill is used in the line of industrial mining equipment designed to process, crushing, separating, or locate precious metals from coal. The SAG mill is one of the major mining equipment pieces and often requires machinery repair and maintenance.  

This is most often due to the large amount of heavy, residue bearing material being churned from grinding mill due to the Large amount. The SAG mill used plates along the inside of the drum, lift the material during rotation, causing them to fall onto each other to crushing. 

A semi-autogenous grinding mill or SAG mill is responsible for materials of Large chunks into Little pieces suitable for processing material. The SAG mill is usually part of the primary stage in the grinding process. Pieces of raw or reduced rock materials into smaller pieces for further processing or sorting. These machines are electrically driven , but changed and have been modified from powering systems over the years.

It may often be necessary to service a variety of industrial gold mining equipment, coal mining equipment, and other relevant major mining equipment. People who work in SAG mills must to understand involved in each phase of the machine repair process the intricate details, rehabilitation of mining equipment and great care. This information will necessity a trained eye and skillful hand, to ensure that the machine working properly.

SAG Mill & Maintenance

Some of the necessary services for the SAG mill machines comprise technical support during the construction and application processes for the mining equipment manufacturers. Other services include the production of parts, mining machinery repair and restoration of mining machinery. This type of equipment is extremely important for the production and economy, and it is necessary to take care when handling the equipment. Professionals should be very knowledgeable in this unit.

When machine has been shut down, or the process is problematic , so do production and profit slowed. Mining machinery maintenance and modifications keep production running at its best. SAG mill operations are no exceptions. In Specific, it is important to ensure that the lifting plates, rotating drums, mill rotators and other machine components their optimal operating functions maintained at all times by ensuring that preventive and routine maintenance completed on schedule and on time.

SAG mill mining machinery, and other mining equipment, are crucial for the mining industry. SAG mill has a far history in mining production and must be handled carefully and with caution to ensure safety and optimal production at any time. Gold-mining equipment and mining equipment are among the most waited mill types mining machinery, which requires maintenance and modification. 

Video Rubicon Minerals Corp: SAG Mill First Run Phoenix Gold Project 



Video How To Test Silver

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Silver is the first metal which was first smelted from ore. It comes from ancient Egyptian empire used and has been forged in household utensils, jewelry, etc. Pure silver is smooth as gold, copper usually alloyed to straighten his strength and can be used for making the production equipment and other items.

Without addition of alloying because of its softness, it would melt. Fine silver is pure Nearly 999/1000 percent, but it is too smooth to make jewelry, out of it a metal added in silver. But something called silver or sterling silver (which in it 92.5 percent pure silver and has 7.5 percent metal ) is pure silver.

Silver is a versatile chemical element. Sterling silver is 92.5 percent silver and 7.5 percent other metals, especially copper. It is harder than pure silver. Pure silver is smooth and often referred to as “fine silver.” Products can often be mistaken as silver when silver (only covered with a thin layer of fine silver). 

But how do you know you really have silver at home? Unless you are an silver holder, who knows quality is silver, and how pure the silver, you buy. You can not have the first clue how to test for silver purity at house. This article will Aid explain the purity of silver and how to confirm that not only is another gray metal.

The most obvious way to know pure silver, and the extent to which it is pure, is to check on your silver jewelry and silverware

Tips to determine purity of silver Or How to test silver

1. Test with a magnet , In the specially using a strong magnet, such as the magnet made of neodymium. Silver is paramagnetic and shows only a weak magnetic effect. If magnet very strong sticking on metal, it has a ferromagnetic core and is not silver. 

Note that there are a few other metals which a magnet will not stick and can be made to look visible as a silver. It is better to carry out the magnetic test in conjunction with another test to ensure that the core is not another metal.

2. Try the ring-test with each coin. Silver makes a really lovely bell like ringing when someone knocked on, especially if they are knocked with a different kind of metal. If you want to try this, you have to find metals silver quarter which made before 1965 in United States, it is made of silver 90% silver US. 

Were during quarters later than 1964 are made of a copper-nickel alloy. The elder quarter will give a whistle, clear ringtone, while the newer district give a thud of a sound. 

3. Perform a chemical analysis test to the point item. Use chemical analysis if no stamps indicating that the silver metal. Use gloves within silver test with chemicals, because if exposed to a corrosive acid solution, it will burn your skin

Note that this method has the potential to damaging silver element.

Buy a silver test. Silver acid tests for pure silver, but if you think your piece is silver, you will use a Little jeweler file to make a mark, revealing what might be under the plating.

Find. An inconspicuous place on the article in question and make a Little scratch on the silver piece. This is necessary in order to test the underlying metal silver it with acid. Scratch the piece a metal file. Scratch off enough so you can get to the surface of any plating layer.

If you do not want your piece scratch, or potentially leave a mark from the acid, you can use a black stone slab. These are generally made with a silver testing kit available. Rub your silver on the surface of the black stone, so that it leaves a thick and relatively Large deposit on the stone. Goal for a line that one thick one-half inch.

Apply a drop of acid to the scratched surface only. When the acid touches any portion of the piece that is not scratched, it will affect the polished look of the piece. If you want to use a black stone, a drop of acid will add to the line that you created on your stone. 

5. Analyze. The analyze  surface on part scratched with the acid. You have to analyze the color, the acid appears as decreases in the piece.
Be sure to follow the instructions and color of your specific silver test. In common, the color scale is as follows:

Bright Red: Fine Silver
Darker Red: 925 Silver
Brown : 800 Silver
Green : 500 Silver
Yellow: Lead or Tin
Dark brown: Brass
Blue: Nickel

This video constitute How to test silver

 

Precious Metal Recovery ( Video )

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Precious Metal Recovery refers to the reclaiming of precious metals from specific scrap materials. Many precious metal recovery services employ state of the art refining techniques, for extracting metals such as gold, silver and platinum etc.

These processes can extract precious non-ferrous-metals from industrial scraps, wires tubes and dishoarded bars. Recovery services are used in a variety of industries including, aerospace, jewelry, medical and the semi-conductor and printed circuit board industries.

These services may also include reducing the metal lots to assaying bars for evaluation, by utilizing thermal processes. Metal refining capabilities can include, melting and thermal reduction through incineration.

Recovery refers to the separation of precious metals from noble-metalliferous materials, some of these materials may include catalysts such as electronic assemblies or printed circuit boards. 

To isolate or remove the metals, procedures such as hydrolysis or pyrolysis are commonly employed. With hydrolysis, the noble-metalliferous materials can be dissolved in hydrochloric acid and chlorine gas solution, or dissolved in Aqua regia, which consists of hydrochloric acid and nitric acid. 

In the procedure known as pyrolysis the precious metals are removed by solidifying in a melt to become cinder, and then oxidized. Some metals may be reduced directly with a gas or salt or nitro hydrate connection.

This is followed by various cleaning stages or are recrystallized, and the metals can then be separated from the salt by calcination. These precious metal materials are first hydrolyzed and then thermally prepared (pyrolysed) thereafter. The recycling product is removed and put several times through the cycle.

Precious metal recovery services are companies that purchase materials such as printed circuit boards, old wires, and industrial scraps that contain various precious metals such as :

o Gold & Silver

o Platinum

o Nickel & Tin

o Rhodium

o Palladium

o Copper & Bronze

These materials are then put through various processes to extract the precious metals from them. This makes good economical and environmental sense.

These services may also include buying old jewelry, and other valuable scrap metals such as :

o Brass

o Copper

o Bronze

o Aluminium

o Phosphor Bronze

These metals can then be smelted down and reused, thus saving valuable resources.

This is Video from Precious Metal Analysis - Instrumental Methods for Gold, Silver, Platinum, Palladium and other PGMs


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How Process Fire Assaying For Mineral (Video)

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Fire assaying for mineral is the oldest and is considered to be the most reliable method of determining the content of gold and silver in rock or concentrate samples. This method is still the industry standard. The reason why it is called ”fire” assay is simply because it involves smelting the sample which has been mixed with lead oxide.

There are six basic steps in the fire assay procedure: 
  • Splitting 
  • weighing 
  • mixing 
  • firing 
  • cupelling
  • parting.
How the process fire assaying for Mineral

First, the crushed and ground sample of ore or concentrate is carefully split down to smaller samples only around 30 grams. These samples are weighed out and added to a crucible. A mixture of lead oxide, a reducing agent and fluxes is then added. The fluxes usually consist of silica sand, borax and sometimes additional additives like fluorite. The fluxes, reductant, lead oxide and sample are then mixed and fired in a muffle furnace.

The contents of the test material into the container then let all the ingredients to melt in the furnace smelting. In the presence of the reducing agent, typically carbon in any form, e.g. flour, the lead oxide is smelted to lead metal which “collects” any silver and gold that may have been in the sample.

The molten mass is taken from the furnace and mixed before being poured into a cone-shaped mold and allowed to cool. The molten lead sinks to the bottom of the mold, carrying any gold and silver with it, while the rest of the components of the ore along with the flux turn into a glassy slag that floats on top.

After cooling, the metallic lead at the bottom of the mold is separated from the glassy slag which is discarded. The lead is called a “button.”

This metallic lead button is then placed into a cupel, a small dish made from bone ash, and placed into a cupelling furnace. In the “cupelling” process, lead metal turns back into oxide which separates away from the precious metals and soaks into the bone ash cupel, leaving the minute amount of precious metals as a metallic speck called a “bead.”

The next step in the process is called parting, where the bead is weighed to determine the amount of gold and silver that was extractable from the original ore sample.

The bead is then heated in hot nitric acid which dissolves the silver, leaving any gold that may have been present. The parted bead is then carefully weighed and amount of gold is related back to the weight of ore or concentrate sample in the first crucible that was burned.

In more modern laboratories, the bead of precious metals that is recovered in the cupel after the lead has been removed is dissolved in aqua regia. The resulting solution is then analyzed by atomic absorption spectrometry, allowing the grade of gold and silver in the original sample to be back calculated.

Fire assaying is a science, and also to some extent is still an art. Certain types of ore contain elements that may interfere with the result. A good fire assayer knows how to modify the composition of the flux to avoid these problems. The fire assayer knows how to determine the gold and silver content of the assay ton of sample that has been presented.


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Metallurgy In Mining Video

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What do we know about metallurgy? Metallurgy is branch of science that deals with the procedures used when extracting metals from ores, purifying and alloying them. This also involves the study of the procedures used when making objects out of metals. Yet, to be able to understand fully all about metallurgy, it would be better to have a short glimpse of the history of metallurgy.

One of the oldest processes of applied science is the process of metallurgy. Its history would give us a good view of how the process developed and its association with metals. The history of metallurgy occurred around 7,000 BC which what they call the age of copper. It is the period between the Stone Age and the Bronze Age which could also be considered the turning point between Stone to Metal. 

The first process was purely accidental when the copper enter into the fireplace campfire hot. Obviously, the copper melted and when it cooled people noticed the change of its shape. The development of the process was also contributed by the magic of the fire. We could learn from the history of metallurgy that people in the old days relied on the fire for the metal processing 

In the 2800 BC comes the Bronze Age which is another development in metallurgy. People have become brilliant that they made an alloy of copper and tin since both was commonly found in the same ore. Which results bronze and bronze has become a commodity was used for the weapons of the armies as well as used as money for trade. 

In the 1500 BC, another breakthrough was found in metallurgy. It is the discovery of iron which was considered the most abundant metal in the earth but was difficult to extract.

By this then, in the 11th century, people pushed their luck and tried to heat the iron with charcoal in such a way that the carbon from the charcoal can be transferred to the iron.

With this, the metal would be hardened and the Age of Steel came. Yet, iron has become a continuous challenge to most metallurgists since it’s very hard which can only be hammered but can’t be melted. In the 513 BC, Chinese were able to think of a furnace strong enough to heat iron.

Metals nowadays are a commodity. From the buildings, the houses, to the littlest tools we use everyday; the magic of metals is involved. Without them, everything wouldn’t be that easy. One after another, metals have developed and evolved. Over the years, people never stopped adding bits to the history of metallurgy making way for the metals to be obviously useful and one of the most important things in our daily lives nowadays.


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Principle Of Ball Mill Mining

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Cone ball mill is a common ball mill mining processing. The ball mill structure of ball mill can change, and it enables the integration of the body and chassis. On the installation, it can be used only once in order to plate at the field. He also used spindle double row spherical roller bearings to replace conventional bearings. After transformation, it can power Approximately 30%, improve the fineness and increase processing capacity Approximately 15%.

Open Pit Mining Process

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Opencast sometimes referred to as open cut mining, surface mining or simply open pit is extracted a mining technique that important minerals from a borrow or an open pit.

There are two types of extraction methods, commonly used in Large scale mining mineral; Open pit mining and tunnel mining or Under ground mining. Opencast mining is used when the minerals are on the surface only in the vicinity are degraded. This is especially when the soil or material covers the minerals are relatively thin and can be easily moved for mining to take place.

Flotation Cell For Mineral Separation ( Video )

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In the mining industry the flotation cell used to separate the valuable mineral ore from mineral impurities, and based on differences from surface properties of the minerals substance to be separated in the flotation cell equipment, where in hydrophilic substances remain in the water phase, whereas the hydrophobic substance will be tied to the air bubbles and will be brought to the surface the solution and form a froth, so that it can be separated from the liquid. In a simple flotation equipment used for the separation of one or more mineral, with other minerals by flotation or commonly referred to as flotation technique, flotation machine is a useful basic equipment for mineral ore separation process from non-ferrous ores and other minerals.

Shaking Table For Gold Separation Process ( Video )

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Gold Separation Process With Spiral Concentrators ( Video )

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The process of separating gold with spiral concentrator is the process of separating gold using equipment by utilizing gravity system for obtaining gold ore. Spiral concentrator is one of the most effective ways and low cost in the mining industry which is used in the separation of mineral ore. One of the benefits of a spiral concentrator devices have no moving parts. The separation process mineral ore concentrates in gold mining in general should be done gradually, and a function of the mineral separation process to separate gold ore from dirt mineral or bearer minerals

Open Pit Gold Mining Video

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Blasting in open pit mine
Open-pit gold mining is the process of mining by way of excavation which was made on the surface of the soil with the aim of finding gold mineral ores and worked for the mine life. In the exposing stage and the process of mineral ore mine in open-pit gold mining, is generally carried out in the gold mining industry on a large scale which required the excavation process and move the rocks in large quantities. In the mining industry, gold obtained by isolating it from rock gold ore (extraction). According to Greenwood et al (1989), rock gold ore decent to be exploited as the gold mining industry, gold content of approximately 25 g / tonne (25 ppm).

Open-pit gold mining the have main objective of the commercial value and open mining operations undertaken with the value of the lowest possible cost in the exploitation of mineral deposits and generate maximum profit. Planning, Selection of the physical design parameters of open pit mining, scheduling program for the extraction of mineral ores is an important stage in the open-pit gold mining.

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