Soft drinks are enormously popular beverages consisting primarily of carbonated water, sugar, and flavorings. Nearly 200 nations enjoy the sweet, sparkling soda with an annual consumption of more than 34 billion gallons. Soft drinks rank as America's favorite beverage segment, representing 25% of the total beverage market. In the early 1990s per capita consumption of soft drinks in the U.S. was 49 gallons, 15 gallons more than the next most popular beverage, water.

Raw Materials
Carbonated water constitutes up to 94% of a soft drink. Carbon dioxide adds that special sparkle and bite to the beverage and also acts as a mild preservative. Carbon dioxide is an uniquely suitable gas for soft drinks because it is inert, non-toxic, and relatively inexpensive and easy to liquefy.

The second main ingredient is sugar, which makes up 7-12% of a soft drink. Used in either dry or liquid form, sugar adds sweetness and body to the beverage, enhancing the "mouth-feel," an important component for consumer enjoyment of a soft drink. Sugar also balances flavors and acids.

Sugar-free soft drinks stemmed from a sugar scarcity during World War II. Soft drink manufacturers turned to high-intensity sweeteners, mainly saccharin, which was phased out in the 1970s when it was declared a potential carcinogen. Other sugar substitutes were introduced more successfully, notably aspartame, or Nutra-Sweet, which was widely used throughout the 1980s and 1990s for diet soft drinks. Because some high-intensity sweeteners do not provide the desired mouth-feel and aftertaste of sugar, they often are combined with sugar and other sweeteners and flavors to improve the beverage.

The overall flavor of a soft drink depends on an intricate balance of sweetness, tartness, and acidity (pH). Acids add a sharpness to the background taste and enhance the thirst-quenching experience by stimulating saliva flow. The most common acid in soft drinks is citric acid, which has a lemony flavor. Acids also reduce pH levels, mildly preserving the beverage.

Very small quantities of other additives enhance taste, mouth-feel, aroma, and appearance of the beverage. There is an endless range of flavorings; they may be natural, natural identical (chemically synthesized imitations), or artificial (chemically unrelated to natural flavors). Emulsions are added to soft drinks primarily to enhance "eye appeal" by serving as clouding agents. Emulsions are mixtures of liquids that are generally incompatible. They consist of water-based elements, such as gums, pectins, and preservatives; and oil-based liquids, such as flavors, colors, and weighing agents. Saponins enhance the foamy head of certain soft drinks, like cream soda and ginger beer.

To impede the growth of microorganisms and prevent deterioration, preservatives are added to soft drinks. Anti-oxidants, such as BHA and ascorbic acid, maintain color and flavor. Beginning in the 1980s, soft drink manufacturers opted for natural additives in response to increasing health concerns of the public.

Impurities in the water are removed through a process of coagulation, filtration, and chlorination. Coagulation involves mixing floc into the water to absorb suspended particles. The water is then poured through a sand filter to remove fine particles of Roc. To sterilize the water, small amounts of chlorine are added to the water and filtered out.

The Manufacturing Process

Most soft drinks are made at local bottling and canning companies. Brand name franchise companies grant licenses to bottlers to mix the soft drinks in strict accordance to their secret formulas and their required manufacturing procedures.

Clarifying the water

1 The quality of water is crucial to the success of a soft drink. Impurities, such as suspended particles, organic matter, and bacteria, may degrade taste and color. They are generally removed through the traditional process of a series of coagulation, filtration, and chlorination. Coagulation involves mixing a gelatinous precipitate, or floc (ferric sulphate or aluminum sulphate), into the water. The floc absorbs suspended particles, making them larger and more easily trapped by filters. During the clarification process, alkalinity must be adjusted with an addition of lime to reach the desired pH level.
Filtering, sterilizing, and dechlorinating the water

2 The clarified water is poured through a sand filter to remove fine particles of floc. The water passes through a layer of sand and courser beds of gravel to capture the particles.

3 Sterilization is necessary to destroy bacteria and organic compounds that might spoil the water's taste or color. The water is pumped into a storage tank and is dosed with a small amount of free chlorine. The chlorinated water remains in the storage tank for about two hours until the reaction is complete.

4 Next, an activated carbon filter dechlorinates the water and removes residual organic matter, much like the sand filter. A vacuum pump de-aerates the water before it passes into a dosing station.
Mixing the ingredients

5 The dissolved sugar and flavor concentrates are pumped into the dosing station in a predetermined sequence according to their compatibility. The ingredients are conveyed into batch tanks where they are carefully mixed; too much agitation can cause unwanted aeration. The syrup may be sterilized while in the tanks, using ultraviolet radiation or flash pasteurization, which involves quickly heating and cooling the mixture. Fruit based syrups generally must be pasteurized.

6 The water and syrup are carefully combined by sophisticated machines, called proportioners, which regulate the flow rates and ratios of the liquids. The vessels are pressurized with carbon dioxide to prevent aeration of the mixture.

Carbonating the beverage

7 Carbonation is generally added to the finished product, though it may be mixed into the water at an earlier stage. The temperature of the liquid must be carefully controlled since carbon dioxide solubility increases as the liquid temperature decreases. Many carbonators are equipped with their own cooling systems. The amount of carbon dioxide pressure used depends on the type of soft drink. For instance, fruit drinks require far less carbonation than mixer drinks, such as tonics, which are meant to be diluted with other liquids. The beverage is slightly over-pressured with carbon dioxide to facilitate the movement into storage tanks and ultimately to the filler machine.

Filling and packaging

8 The finished product is transferred into bottles or cans at extremely high flow rates. The containers are immediately sealed with pressure-resistant closures, either tinplate or steel crowns with corrugated edges, twist offs, or pull tabs.

9 Because soft drinks are generally cooled during the manufacturing process, they must be brought to room temperature before labeling to prevent condensation from ruining the labels. This is usually achieved by spraying the containers with warm water and drying them. Labels are then affixed to bottles to provide information about the brand, ingredients, shelf life, and safe use of the product. Most labels are made of paper though some are made of a plastic film. Cans are generally pre-printed with product information before the filling stage.

10 Finally, containers are packed into cartons or trays which are then shipped in larger pallets or crates to distributors.

Quality Control
Soft drink manufacturers adhere to strict water quality standards for allowable dissolved solids, alkalinity, chlorides, sulfates, iron, and aluminum. Not only is it in the interest of public health, but clean water also facilitates the production process and maintains consistency in flavor, color, and body. Microbiological and other testing occur regularly. The National Soft Drink Association and other agencies set standards for regulating the quality of sugar and other ingredients. If soft drinks are produced with low-quality sugar, particles in the beverage will spoil it, creating floc. To prevent such spoilage, sugar must be carefully handled in dry, sanitized environments.

It is crucial for soft drink manufacturers to inspect raw materials before they are mixed with other ingredients, because preservatives may not kill all bacteria. All tanks, pumps, and containers are thoroughly sterilized and continuously monitored. Cans, made of aluminum alloy or tin-coated low-carbon steel, are lacquered internally to seal the metal and prevent corrosion from contact with the beverage. Soft drink manufacturers also recommend specific storage conditions to retailers to insure that the beverages do not spoil. The shelf life of soft drinks is generally at least one year.

Recycling
The $27 billion dollar soft drink industry generated about 110 billion containers each year in the early 1990s. About half of soft drink containers were aluminum cans and the other half, about 35 billion, were PET plastic bottles. Nearly 60% of all soft drink containers were recycled, the highest rate for any packaging in the United States. Environmental concerns continued to lead to improvements and innovations in packaging technology, including the development of refillable and reusable containers.

The Future
In the 1990s there were more than 450 types of soft drinks on the market and new flavors and sweeteners are developed all the time to meet market demands. In the future, advanced technology will lead to greater efficiency of soft drink production at all stages. New methods of water clarification, sterilization, and pasteurization will improve production and minimize the need for preservatives in soft drinks. Concerns with consumer health, safety, and the environment will continue to have a positive impact on trends in the soft drink industry.

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Winemaking, or vinification, is the production of wine, starting with selection of the grapes or other produce and ending with bottling the finished wine. Although most wine is made from grapes, it may also be made from other fruit or non-toxic plant material. Mead is a wine that is made with honey being the primary ingredient after water.

Winemaking can be divided into two general categories: still wine production (without carbonation) and sparkling wine production (with carbonation).

PROCESS
After the harvest, the grapes are crushed and allowed to ferment. Red wine is made from the must (pulp) of red or black grapes that undergo fermentation together with the grape skins, while white wine is usually made by fermenting juice pressed from white grapes, but can also be made from must extracted from red grapes with minimal contact with the grapes' skins. Rosé wines are made from red grapes where the juice is allowed to stay in contact with the dark skins long enough to pick up a pinkish color, but little of the tannins contained in the skins.

During this primary fermentation, which often takes between one and two weeks, yeast converts most of the sugars in the grape juice into ethanol (alcohol). After the primary fermentation, the liquid is transferred to vessels for the secondary fermentation. Here, the remaining sugars are slowly converted into alcohol and the wine becomes clear. Wine is then allowed to age in oak barrels before bottling, which add extra aromas to the wine, while others are bottled directly. The time from harvest to drinking can vary from a few months for Beaujolais nouveau wines to over twenty years for top wines. However, only about 10% of all red and 5% of white wine will taste better after five years than it will after just one year.[1] Depending on the quality of grape and the target wine style, some of these steps may be combined or omitted to achieve the particular goals of the winemaker. Many wines of comparable quality are produced using similar but distinctly different approaches to their production; quality is dictated by the attributes of the starting material and not necessarily the steps taken during vinification.

Variations on the above procedure exist. With sparkling wines such as Champagne, an additional fermentation takes place inside the bottle, trapping carbon dioxide and creating the characteristic bubbles. Sweet wines are made by ensuring that some residual sugar remains after fermentation is completed. This can be done by harvesting late (late harvest wine), freezing the grapes to concentrate the sugar (ice wine), or adding a substance to kill the remaining yeast before fermentation is completed; for example, high proof brandy is added when making port wine. In other cases the winemaker may choose to hold back some of the sweet grape juice and add it to the wine after the fermentation is done, a technique known as süssreserve.

The process produces wastewater, pomace, and lees that require collection, treatment, and disposal or beneficial use.

* Harvesting and destemming
Harvest is the picking of the grapes and in many ways the first step in wine production. Grapes are either harvested mechanically or by hand. The decision to harvest grapes is typically made by the winemaker and informed by the level of sugar (called °Brix), acid (TA or Titratable Acidity as expressed by tartaric acid equivalents) and pH of the grapes. Other considerations include phenological ripeness, berry flavor, tannin development (seed colour and taste). Overall disposition of the grapevine and weather forecasts are taken into account.

* Crushing and primary fermentation
Crushing is the process of gently squeezing the berries and breaking the skins to start to liberate the contents of the berries. Desteming is the process of removing the grapes from the rachis (the stem which holds the grapes).

* Pressing
Pressing is the act of applying pressure to grapes or pomace in order to separate juice or wine from grapes and grape skins. Pressing is not always a necessary act in winemaking; if grapes are crushed there is a considerable amount of juice immediately liberated (called free-run juice) that can be used for vinification. Typically this free-run juice is of a higher quality than the press juice. However, most wineries do use presses in order to increase their production (gallons) per ton, as pressed juice can represent between 15%-30% of the total juice volume from the grape.

* Pigeage
Pigeage is a French winemaking term for the traditional stomping of grapes in open fermentation tanks.

* Cold and heat stabilization
* Secondary fermentation and bulk aging
During the secondary fermentation and aging process, which takes three(3) to six(6) months, the fermentation continues very slowly. The wine is kept under an airlock to protect the wine from oxidation.

* Malolactic fermentation
Malolactic fermentation is carried out by bacteria which metabolize malic acid and produce lactic acid and carbon dioxide. The resultant wine is softer in taste and has greater complexity. The process is used in most red wines and is discretionary for white wines.

* Laboratory tests
* Blending and fining
Different batches of wine can be mixed before bottling in order to achieve the desired taste. The winemaker can correct perceived inadequacies by mixing wines from different grapes and batches that were produced under different conditions. These adjustments can be as simple as adjusting acid or tannin levels, to as complex as blending different varieties or vintages to achieve a consistent taste.

* Preservatives
The most common preservative used in winemaking is sulfur dioxide. Another useful preservative is potassium sorbate.

* Filtration
Filtration in winemaking is used to accomplish two objectives, clarification and microbial stabilization. In clarification, large particles that affect the visual appearance of the wine are removed. In microbial stabilization, organisms that affect the stability of the wine are removed therefore reducing the likelihood of re-fermentation or spoilage.

* Bottling
A final dose of sulfite is added to help preserve the wine and prevent unwanted fermentation in the bottle. The wine bottles then are traditionally sealed with a cork, although alternative wine closures such as synthetic corks and screwcaps, which are less subject to cork taint, are becoming increasingly popular

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The brewing process is typically divided into 7 steps: mashing, lautering, boiling, fermenting, conditioning, filtering, and filling.

Today, many simplified brewing systems exist which can be used at home or in restaurants. These homebrewing systems are often employed for ease of use, although some people still prefer to do the entire brewing process themselves.

Mashing
Mashing is the process of combining a mix of milled grain, known as the grist (typically malted barley with supplementary grains as maize, sorghum, rye or wheat; in a ratio of 90-10 up to 50-50), with water, and heating this mixture up which rests at certain temperatures (notably 45°C, 62°C and 73°C [3][4]) to allow enzymes in the malt to break down the starch in the grain into sugars, typically maltose.

Wort Separation
Wort separation is the separation of the wort containing the sugar extracted during mashing from the spent grain. It can be carried out in a mash tun outfitted with a false bottom, a lauter tun, a special-purpose wide vessel with a false bottom and rotating cutters to facilitate flow, a mash filter, a plate-and-frame filter designed for this kind of separation, or in a Strainmaster. Most separation processes have two stages: first wort run-off, during which the extract is separated in an undiluted state from the spent grains, and Sparging, in which extract which remains with the grains is rinsed off with hot water.

Boiling
Boiling the malt extracts, called wort, ensures its sterility, and thus prevents a lot of infections. During the boil hops are added, which contribute bitterness, flavour, and aroma compounds to the beer, and, along with the heat of the boil, causes proteins in the wort to coagulate and the pH of the wort to fall. Finally, the vapours produced during the boil volatilise off flavours, including dimethyl sulfide precursors.

The boil must be conducted so that it is even and intense. The boil lasts between 50 and 120 minutes, depending on its intensity, the hop addition schedule, and volume of wort the brewer expects to evaporate.

Fermenting
After the wort is cooled and aerated — usually with sterile air — yeast is added to it, and it begins to ferment. It is during this stage that sugars won from the malt are metabolized into alcohol and carbon dioxide, and the product can be called beer for the first time. Fermentation happens in tanks which come in all sorts of forms, from enormous tanks which can look like storage silos, to five gallon glass carboys in a homebrewer's closet.

Most breweries today use cylindro-conical vessels, or CCVs, have a conical bottom and a cylindrical top. The cone's aperture is typically around 60°, an angle that will allow the yeast to flow towards the cones apex, but is not so steep as to take up too much vertical space. CCVs can handle both fermenting and conditioning in the same tank. At the end of fermentation, the yeast and other solids which have fallen to the cones apex can be simply flushed out a port at the apex.

Kraeusen in an English brewery's fermentation tankOpen fermentation vessels are also used, often for show in brewpubs, and in Europe in wheat beer fermentation. These vessels have no tops, which makes harvesting top fermenting yeasts very easy. The open tops of the vessels make the risk of infection greater, but with proper cleaning procedures and careful protocol about who enters fermentation chambers, the risk can be well controlled.

Fermentation tanks are typically made of stainless steel. If they are simple cylindrical tanks with beveled ends, they are arranged vertically, as opposed to conditioning tanks which are usually laid out horizontally. Only a very few breweries still use wooden vats for fermentation as wood is difficult to keep clean and infection-free and must be repitched more or less yearly.

After high kraeusen a bung device (German: Spundapparat) is often put on the tanks to allow the CO2 produced by the yeast to naturally carbonate the beer. This bung device can be set to a given pressure to match the type of beer being produced. The more pressure the bung holds back, the more carbonated the beer becomes.

Conditioning
When the sugars in the fermenting beer have been almost completely digested, the fermentation slows down and the yeast starts to settle to the bottom of the tank. At this stage, the beer is cooled to around freezing, which encourages settling of the yeast, and causes proteins to coagulate and settle out with the yeast. If a separate conditioning tank is to be used, it is at this stage that the beer will be transferred into one. Unpleasant flavors such as phenolic compounds become insoluble in the cold beer, and the beer's flavor becomes smoother. During this time pressure is maintained on the tanks to prevent the beer from going flat.

A similar technique is used in home brewing, wherein the beer is simply siphoned into another vessel (usually a carboy), leaving the now-dormant yeast and other sediment behind. The batch is then sometimes refrigerated for the aforementioned benefits.

Conditioning can take from 2 to 4 weeks, sometimes longer, depending on the type of beer. Additionally lagers, at this point, are aged at near freezing temperatures for 1-6 months depending on style. This cold aging serves to reduce sulfur compounds produced by the bottom-fermenting yeast and to produce a cleaner tasting final product with fewer esters.

If the fermentation tanks have cooling jackets on them, as opposed to the whole fermentation cellar being cooled, conditioning can take place in the same tank as fermentation. Otherwise separate tanks (in a separate cellar) must be employed. This is where aging occurs.

Filtering

Filtering the beer stabilizes the flavour, and gives beer its polished shine and brilliance. Not all beer is filtered. When tax determination is required by local laws, it is typically done at this stage in a calibrated tank.

Filters come in many types. Many use pre-made filtration media such as sheets or candles, while others use a fine powder made of, for example, diatomaceous earth, also called kieselguhr, which is introduced into the beer and recirculated past screens to form a filtration bed.

Filters range from rough filters that remove much of the yeast and any solids (e.g. hops, grain particles) left in the beer, to filters tight enough to strain color and body from the beer. Normally used filtration ratings are divided into rough, fine and sterile. Rough filtration leaves some cloudiness in the beer, but it is noticeably clearer than unfiltered beer. Fine filtration gives a glass of beer that you could read a newspaper through, with no noticeable cloudiness. Finally, as its name implies, sterile filtration is fine enough that almost all microorganisms in the beer are removed during the filtration process.

Packaging
Packaging is putting the beer into the containers in which it will leave the brewery. Typically this means in bottles, aluminium cans and kegs, but it might include bulk tanks for high-volume customers.

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Forming Oil

Oil is formed from the remains of tiny plants and animals (plankton) that died in ancient seas between 10 million and 600 million years ago. After the organisms died, they sank into the sand and mud at the bottom of the sea.

­Over the years, the organisms decayed in the sedimentary layers. In these layers, there was little or no oxygen present. So microorganisms broke the remains into carbon-rich compounds that formed organic layers. The organic material mixed with the sediments, forming fine-grained shale, or source rock. As new sedimentary layers were deposited, they exerted intense pressure and heat on the source rock. The heat and pressure distilled the organic material into crude oil and natural gas. The oil flowed from the source rock and accumulated in thicker, more porous limestone or sandstone, called reservoir rock. Movements in the Earth trapped the oil and natural gas in the reservoir rocks between layers of impermeable rock, or cap rock, such as granite or marble

Preparing to Drill

Once the site has been selected, it must be surveyed to determine its boundaries, and environmental impact studies may be done. Lease agreements, titles and right-of way accesses for the land must be obtained and evaluated legally. For off-shore sites, legal jurisdiction must be determined.

Once the legal issues have been settled, the crew goes about preparing the land:

The land is cleared and leveled, and access roads may be built.
Because water is used in drilling, there must be a source of water nearby. If there is no natural source, they drill a water well.

They dig a reserve pit, which is used to dispose of rock cuttings and drilling mud during the drilling process, and line it with plastic to protect the environment. If the site is an ecologically sensitive area, such as a marsh or wilderness, then the cuttings and mud must be disposed offsite -- trucked away instead of placed in a pit.

Once the land has been prepared, several holes must be dug to make way for the rig and the main hole. A rectangular pit, called a cellar, is dug around the location of the actual drilling hole. The cellar provides a work space around the hole, for the workers and drilling accessories. The crew then begins drilling the main hole, often with a small drill truck rather than the main rig. The first part of the hole is larger and shallower than the main portion, and is lined with a large-diameter conductor pipe. Additional holes are dug off to the side to temporarily store equipment -- when these holes are finished, the rig equipment can be brought in and set up.

Depending upon the remoteness of the drill site and its access, equipment may be transported to the site by truck, helicopter or barge. Some rigs are built on ships or barges for work on inland water where there is no foundation to support a rig (as in marshes or lakes.

Drilling

The crew sets up the rig and starts the drilling operations. First, from the starter hole, they drill a surface hole down to a pre-set depth, which is somewhere above where they think the oil trap is located. There are five basic steps to drilling the surface hole:

Place the drill bit, collar and drill pipe in the hole.
Attach the kelly and turntable and begin drilling.

As drilling progresses, circulate mud through the pipe and out of the bit to float the rock cuttings out of the hole.

Add new sections (joints) of drill pipes as the hole gets deeper.
Remove (trip out) the drill pipe, collar and bit when the pre-set depth (anywhere from a few hundred to a couple-thousand feet) is reached.

Once they reach the pre-set depth, they must run and cement the casing -- place casing-pipe sections into the hole to prevent it from collapsing in on itself. The casing pipe has spacers around the outside to keep it centered in the hole.

The casing crew puts the casing pipe in the hole. The cement crew pumps cement down the casing pipe using a bottom plug, a cement slurry, a top plug and drill mud. The pressure from the drill mud causes the cement slurry to move through the casing and fill the space between the outside of the casing and the hole. Finally, the cement is allowed to harden and then tested for such properties as hardness, alignment and a proper seal.

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The technique of glass making too is based on similar lines. People learned to make the first glass containers about two thousand years ago. Molten glass was collected on the ends of hollow iron pipes and then expanded by blowing through the pipes. Slowly, people learnt to blow molten glass into moulds. Glass bottle making machines were introduced in the thirties.

The first plastics blow molding machine was designed in the early forties; the first plastic bottles were manufactured using polythene.

In the early seventies, environmentalists began arguing on the grounds that glass and plastic bottles added to pollution. This led to the setting up of numerous recycling centers where people could return bottles for reuse in other bottles. Most of the recycled plastic is used to manufacture lower quality plastic than those used to make bottles.

There are four main ingredients used to manufacture glass:

1. Silica sand,
2. Soda ash,
3. Limestone
4. Recycled glass (cullet).

Small quantities of other materials give glass its colour.

The Process
· All the materials are first weighed then mixed, and then poured into large
furnaces. The temperature in the furnace ranges from about 1100 – 1590
degrees Celsius. This melts all the ingredients into Molten (liquid) glass.
Computers monitor the whole process.

· From the furnace, the Molten glass goes to a bottle-making machine. A
measure of molten glass (this is called a GOB) is delivered to the machine to
make a bottle or jar.

· The bottles then pass through electronic inspection machines, which
automatically detect faults Rejected damaged bottles, are returned to the raw
materials area and recycled for making new glass.

· The bottles are then packed onto pallets. Each pallet can contain as many as
5000 bottles. The pallet is then covered in a large plastic envelope that has
been shrunk until tight. This makes sure the pallet is stable, ready for
transportation to the manufactures for filling.

Bottle Making (Molding Process)

Annealing is done by reheating the glass and gradually cooling it. Such a process removes the stresses and strains in the glass after shaping. This is an important step and if not done may cause the glass to shatter as a result of the build up of tension caused by uneven cooling. After the bottles have cooled to room temperature, they are inspected and finally packaged.

Plastic bottles may be made from polyethylene, polypropylene or polyvinyl chloride. Large cold drink bottles are made of polyethylene terephalate (PET). These bottles are designed in such a way that the gases used to carbonate the soft drinks are unable to escape.

There are three different methods used for processing plastic bottles – extrusion blow molding (in which the parison is tube shaped), injection blow molding (in which the parison is prepared by injecting molten plastic through a small hole) and injection stretch blow molding (in which the plastic is blown into the mould while it is simultaneously being stretched by a metal rod).

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MINING DIAMONDS
Of all the diamonds mined in the world each year, less than half are gem quality; the rest fall into two other main categories known as near-gem quality and industrial quality diamonds. Gem quality diamonds display a high standard of excellence in quality and are used in jewellery. The clarity of these diamonds ranges from flawless through to visible inclusions. Near-gem quality diamonds represent those stones of a quality between gem and industrial, that in fact can be used as either depending on the individual stone. These stones have clarity grades ranging from visible inclusions through to industrial. Industrial quality diamonds are low quality or badly included stones and are suitable only for industrial use; for example, they are used in dentist's drills and earthmoving equipment.

Diamonds are recovered by way of pipe or alluvial mining.

Pipe Mining:
Pipe mining refers to the extraction of diamonds from volcanic pipes. Typically, a very large area has to be covered. An average of 250 tons of ore must be mined in order to produce a one-carat gem uality polished diamond. In most countries, a diamond pipe mine is composed of kimberlite, or blue ground. Initially kimberlite is dug from the surface of the pipes in rough opencast mining. Once the surface deposits have been exhausted, shafts are sunk into the ground at the edge of the pipes, and tunnels are driven into the eeper parts of the pipes.

In open cut mining, the ore is dislodged by blasting and then loaded by excavators into 120-ton dump trucks. The ore is then transported to the processing plant where the diamonds are extracted. The processing techniques are purely physical and involve crushing, scrubbing, screening and gravity separation of the diamond-bearing ore. Final diamond recovery is achieved by the use of x-ray sorting machines. The machines can detect and remove diamond material because the diamonds fluoresce under x-ray.

Alluvial Mining:
This process involves the extraction of diamonds from riverbeds or ocean beaches. Millions of years ago, at the time the diamond pipes were formed, some diamonds were weathered out of the pipes and carried great distances long rivers and even into oceans. In order to extract these diamonds from beaches, a wall is built to hold back the surf. Up to 25 meters of sand is bulldozed aside to reach the diamond-bearing level. Once reached, the diamond-bearing earth is removed and transported to screening plants.

Screening Process:
Once a mining operation yields ore, the diamonds must be sorted from the other materials. This process relies primarily on diamond's high density. An old but effective method is to use a washing pan, which forces heavy minerals like diamond to the bottom and waste to the top. Cones and cyclones use swirling heavy fluids mixed with crushed ore to achieve density separations. With 99 percent of the waste in the ore removed, further separations may use either a grease table or an x-ray separator. Final separation and sorting is done by eye.
Crushed ore is mixed with a muddy water suspension, called puddle, and all is stirred by angled rotating blades in the circular washing pan. Heavier minerals settle to the bottom and are pushed toward an exit point, while lighter waste rises to the top and overflows as a separate stream of material. The surface of diamond is highly unusual in that it resists being wetted by water but sticks readily to grease. Here, wet gravel washes across 3 inclined surfaces covered with beeswax and paraffin. Diamonds stick to the grease while wetted waste minerals flow past. The operator routinely scrapes the material that adheres to the table into a grease pot, using a trowel. The grease in the pot is melted and the diamonds are removed in a strainer. More automated systems use a rotating grease belt and craper.

Cones (left) and cyclones (right) use heavy-media separation. Diamond-bearing concentrate is mixed with a fluid near the density of diamond. Separation occurs in cones and cyclones by swirling the mixture at low and high velocities respectively. In the cone, rotational mixing permits lighter minerals to float to the top and run out as overflow, while diamonds and dense minerals sink to the bottom and are sucked out ith a compressed air siphon.

In the cyclone, fast rotation of the suspension drives heavy minerals to the conical wall, where they sink to the bottom and are extracted, while float waste minerals are sucked from the center of the vortex. Cyclones are about 99.999% efficient at concentrating diamonds and similarly dense inerals from the original ore. The x-ray separator system acts on a thin stream of particles from the concentrate accelerated off a moving belt into the air, where they encounter an intense beam of x-rays. Any diamond fluoresces in the x-rays, activating a photomultiplier that triggers a jet of air, deflecting the diamonds (blue) into a collector bin.

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Depending on the depth of the coal layers (seams), extraction is achieved by means of open-cast (down to a depth 500m) or underground mines.

An opencast operation has the appearance of an enormous hole, organised a bit like a stadium with terraces, along which machines dig into the seams. But what a stadium! The biggest opencast mines are several kilometres in length and hundreds of meters in depth. In underground mines, the coal is extracted by means of vertical or inclined shafts. At each level where coal is present, these shafts are linked together by a vast network of galleries (10 to 20 m² in cross-section). These networks can be made up of several dozens of kilometres of galleries. The coal is extracted by enormous machines (the coalcutters). It is transported to the surface where it is separated from the sands and clays by flotation (the coal floats and the other mineral materials, known as “steriles”, sink to the bottom). Extraction by opencast mining is more productive and less expensive than underground mining. As a result it is more profitable. Working conditions are also a significantly less dangerous. Unfortunately, opencast mining is less environmentally friendly; the countryside is disfigured and the surface activity tends to pollute the atmosphere within the locality.

The majority of coalmines in the world are underground.

Methods of extraction of coal:

- Opencast mining: the soil layers located above the first coal layer (the overburden) are removed. Then extraction can begin. When the hole is sufficiently large, digging continues as far as the subsequent coal layer, where the coal is extracted in the same way, simultaneously with continued extraction of the first layer, and so on. Each of the coal layers is called a “discovery”. The mine gradually becomes a giant amphitheatre, the terraces of which are made up of the layers of coal being extracted. It is more a terracing activity than mining. Giant excavators dig out the coal. Their buckets can contain up to 300 tons of rock. The production from an opencast or strip mine starts 2 to 5 years after the initial work. The technique is less expensive, more profitable and less dangerous than extraction by underground mining. Nevertheless it is little used in Europe, where the coal is generally too deeply buried.

- Underground mines: to reach the coal-bearing rocks, vertical shafts are dug, into which lifts and other systems for links with the surface are installed. At the levels of the coal-bearing seams (layers), digging takes place horizontally, following each seam for as long as possible. Several techniques are used:
In each seam exploited, regularly spaced large pillars of coal are left in place to support the roof: this is called the “room and pillar method”;
Or two parallel tunnels are dug and a machine (a giant rasp or undercutter) goes backwards and forwards between these tunnels, extracting coal at each step: it is the “long coal face” or “long wall” method, which allows recovery of a little more coal than the preceding method. As the coalface moves forward, the roof is allowed to collapse behind (miners talk about “thundering”). The main disadvantage is that the effects of these roof collapses are sometimes felt on the surface, and the buildings and roadways located above the mine suffer the consequences of subsidence: they crack and sometimes even disappear into a hole! To solve this problem, the deliberate collapsing of the roof can be replaced by a filling procedure: the «sterile» rocks replace the extracted coal. But that is more expensive;
In mountainous regions, the galleries can be dug horizontally, directly into the side of the hill, whereas, on the plains, infrastructures are necessary to bring the coal-bearing rocks to the surface. Pumping and drainage equipment is essential although if the mines are in the mountains the evacuation of water usually happens naturally. Conveyors or trains of large wagons transport the extracted coal to the vertical shafts. Finally the coal is taken up to the surface by means of a bucket conveyor driven by very powerful electric motors.

MACHINERIES USED:

Machines make mining easier, quicker, and sometimes safer. Here are some of the machines used in mining:

* Surface Mining:

- Wheel loaders: These are used when a lot of mining materials need to be moved at one time.

- Excavator: Most surface mines have one of these. This machine is used to do the digging. Usually this machine dumps the materials that it dug up into a dump truck.

- Dump Trucks: These are used to take away or move materials. You can see how big it is compared to the driver. Sometimes these are called monster trucks because they are so big.

- Crawler-tractor [bull dozer]: Sometimes these are called dozers. Instead of rubber tires, these have chains. Chain tractors are used on land where rubber tires won't work too well--like in mud or on mountain slopes. Dozers push dirt from one place to another. When mines close and they begin to fix the land that has been changed, dozers push dirt and materials where they need to go.

- Motor grader: These are used to make the ground level when they are clearing off the land for mining or fixing it when they are done.

* Underground mining:

- Articulated Dump Trucks: These are used to move large amounts of material in the mine. They can turn easier inside mines than most trucks can.

- Continuous miner: This machine is used to cut out long sections of the inside walls of the mine. They use this machine instead of blasting and drilling. Click here for pictures.

- Longwall mining equipment: This is used to cut out the coal in layers. Part of the machinery will hold up the roof, too. Click here for a picture.

- Shuttle car: These were used to take out the coal or minerals from the mine. They look a little like our buttons on the left, but not colorful. The ore or coal was loaded into these to be taken out of the mine. Trucks are used for this in up-to-date mines.

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