Dredging and Digging for Diamonds in Liberia

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Alluvial diamond mining not as risky as industry believes

Alluvial diamond mining not as risky as industry believes

It's A Rough World by Louis Pearl G.G.

  Posted on February 19, 2014 by Wyatt Yeager

  Comment

Rough Diamond Trading:

The mining and trading of rough diamonds is worldwide today. When we look at the industry, we can find diamond mining and or diamond trading on every continent except Antarctica.

Africa: Windhoek Namibia, Botswana, Luanda Angola, Kinshasa DRC, Cape Town, Pretoria, Johannesburg South Africa, Conakry Guinea, Nairobi Kenya, Freetown Sierra Leone, Nigeria, Zimbabwe, Cameroon, Ghana., Zimbabwe.

Europe: London, England, Yakutia, Moscow Russia, Geneva, Zurich Switzerland, Antwerp Belgium,

Middle East: Tel Aviv Israel, Dubai,

Asia: Hong Kong, Shangri La, Shanghai China, Mumbai (Bombay) India.

Americas: Northern Canada, New York, Los Angeles U.S.A, Brazil

South Pacific: Australia

Some countries are sourcing markets of rough diamonds, others are trading markets for rough diamonds. Regardless of whether mining is alluvial, hard rock or industrial bort, it is essential that all trade is of non-conflict origin, criminal-free and terrorist-free. Although blood diamonds are pretty much non-existent today, there are still a couple of countries who do not use the best judgment in bringing goods to market.

As long as the rough diamond seller can supply the necessary documents for exporting, including Kimberly Certificates, export documents etc., it is not a problem to ascertain the rough is conflict free (Zimbabwe is the exception).

What is more difficult to determine is whether a particular buyer or seller is legitimate. I have seen rough diamond buyers come to the TTM (Table Top Meeting) with proof of funds or POF using leased financial instruments. They may be Bank Guarantees, Standby Letters of Credit, 103/23 etc. It is not that these instruments are not real; rather the problem is that the buyer has no access to the funds other than for the sole purpose of a POF (Proof of Funds).

Buyers use leased instruments to get the seller to bring the goods to Malca-Amit or Brinks. However, they have no ability to actually buy the goods and are dependent upon a third party to buy the goods at the Table Top Meeting. You don’t have to be a genius to see that this is a recipe for disaster. I have experience with these instruments and I can help you determine if you have a real buyer.

Sellers are also guilty of shenanigans. I have never seen a manifest that matched the parcel contents. The less detailed the manifest, the more likely it is far from accurate. When a manifest details the shapes (sawable, makeable, cleavage, flat etc.), and the clarity details are given (internally flawless, VVS, VS, SI, I) ,and color details are given (D-Z) it shows that the parcel was actually graded with the proper criteria.

However, it does not mean it was graded accurately. The only way you can determine if a diamond manifest is accurate is to examine the goods at the TTM or before they leave the source country. This requires expenditure either way. However, the cost of going to a Table Top Meeting is usually many times the cost to accomplish this task in the source country. Additionally, when you peruse goods in the source country, you can look at exactly what you want, and you have greater flexibility in choosing, rejection and pricing. You also know your purchase is legitimate.

Going to a source country can have its perils. There is an old quote; “Those who have the money will get the experience, and those who have the experience will get the money”. You can travel to the source country without much risk if you have a good understanding of that country and if you have vetted your supplier. It is irrelevant if you buy goods using the Rappaport Report or Adtec as your pricing guide. What is important is experience and wisdom.

Mining Your Own Business

I cannot count all the “opportunities” I have been presented with in the mining sector of the diamond business. I was a past Vice President and board member of Sao Luis Mining, a publicly traded mining company out of Brazil. It took us years to lose our money, but in the end we were successful in doing just that.

All of us in the venture were experienced in diamonds, mining, finance and public offerings. Despite our many talents and skills we were unable to take a property with a large supply of diamonds and make a go of it. Why we failed is a book in itself. I won’t bore you with the details. What I will do, is show you what is involved in putting together a mining operation and it will be self evident why there are so few successful mining operations.

The pictures in the slide show display our property, some of the diamonds on our property and a detailed layout of the diamond equipment needed in a modern alluvial mining operation. This information provided to you free of charge, would cost you many thousands of dollars if you were to pay someone to do the research and put it together for you. It is especially valuable to anyone thinking of investing in mining or to someone who has a concession and is trying to get it financed.

We spent years completing our environmental studies, getting our licenses, permits, geological reports, assays, financial feasibility and cost and income reports. It was a never ending cycle of stop and starts, ups and downs; all the while the money is flowing out like the Amazon into the ocean. The other money eating monster is one that cannot be considered in your projections. I call it the ‘X’ factor. This is when something goes wrong that no one could have imagined. Except that it happens far more often then even the most pessimistic person could imagine.

Just as an example, the DMS or Dense Media Separation Machine a $600,000 beauty is made in South Africa. When you ship this monster (see slide show below) you need to tell the truck driver not to go faster than 3-5 miles an hour down your unpaved road or you can destroy the insides. (It will be out of balance) Wait until you see how much fun you can have trying to get it repaired in your remote location. You will roar with laughter when they tell you how long it will take to get the parts and how much this small problem is going to cost you. Good times had by all!

Because you are nearly always working in a third or forth world country, you can expect that everything will take three times as long as projected and will cost two to three times as much as you were told it will cost. Most companies fail because they run out of money before they have a chance to be successful. Other companies fail because the owners just get sick and tired and no longer wish to sit in the bush
with the bugs, snakes and local bandits, some of whom wear uniforms, ties and suits.

There are a million reasons why a mining operation will fail. There are few companies who have the knowledge and resources, both human and financial to succeed. To do a mining operation properly, it will take approximately $7-12 million investment and two to three years.

There is an exception to this rule. If you have a concession and you have enough money to buy a pan and some camping equipment and food supplies, you can make a good living going into the mud yourself for a few months at a time. It is not a romantic as having a publicly traded diamond mining company, but you have a better chance of making money.

For the full article including pictures click here: http://roughdiamondgemologist.com/its-a-rough-world.html

BHP Names Cutt to Succeed Yeager as Petroleum Unit President

BHP Billiton Ltd. (BHP), the world’s largest mining company, named diamond unit president Tim Cutt to succeed the retiring Michael Yeager as head of its petroleum division as part of a senior management shakeup.

Yeager, a graduate of the U.S. Naval Academy, will retire on July 1, Melbourne-based BHP said today in a statement. Alberto Calderon will be replaced as aluminum President by Daniel Malchuk, though will remain as an advisor to incoming Chief Executive Officer Andrew Mackenzie, who will succeed Marius Kloppers as CEO on May 10.

Yeager, who led BHP’s $20 billion move into the U.S. shale gas industry, joined the petroleum unit in 2006 after 25 years with Exxon Mobil Corp., according to BHP’s website. Before becoming the top oil executive, Yeager was vice president of Exxon Mobil Development Co. where he was responsible for 22 projects worldwide.

“The removal of a layer of management brings the operations closer to the CEO and ensures alignment between strategic and managerial leadership,” Mackenzie said in the statement.

Before becoming diamond unit president in 2011, Cutt led the company’s petroleum production activities after joining from Exxon Mobil in 2007.

To contact the reporter on this story: Elisabeth Behrmann in Sydney atebehrmann1@bloomberg.net

To contact the editor responsible for this story: Jason Rogers at jrogers73@bloomberg.net

Diamond Cutting by Gary Petersen

I know that there are people out there that have an interest in the equipment we use in diamond and gem cutting.  So I am putting this page together to show the equipment we use.  Along with some explanations as to what the photos show and how the equipment is used.

The Rough and Sawing

It all starts with the rough, small parcel of approximately 22cts.

The cutter examines the rough and marks it for sawing.

17.85 ct marked for sawing

The diamond saw.

A diamond being sawed.  The diamond saw is a very thin copper blade coated with diamond dust, its the orientation of the diamond in its cutting direction against the saw blade that allows the diamond to be sawn.  The cutting direction is perpendicular to the dodecahedral grain.

17.85ct sawed in half.

The Girdling

The girdling process is the shaping of the diamond into its finished shape. This process  goes against the grain of the diamond and is done with the utmost care. The girdle of the diamond can also be faceted to get its final shape.

This is the girdling machine, this is a single head unit that has the ability to off set the diamond, this allows the cutter to center the diamond as well as make other elliptical shapes.

Here you see the girdling process, the diamond cemented on the dop spins at approximately 500 rpm, with a diamond being held in a girdling stick that does the shaping.  When your finished shaping the diamond it then goes to the cutting bench.

The Diamond Cutting Bench

This diamond cutting bench is constructed of angle iron, with a 1″ steel table.  The bench has to be substantial in order to spin the 12″ cast iron lap at approximately 2500 rpms, without vibration.  Diamond cutting is a grinding process, the tools that are shown here allow the cutter to hold the diamond in position against the lap to grind and polish the facets into place.

          Here is the cast iron lap with three stones running on it. The rings you see on the lap are cutting and polishing rings, the outer wide ring is for polishing and the inner thin rings are for cutting.

My Diamond Cutting Bench at work.  The tangs and dops you see around the bench are used to hold the diamonds while being cut.

The Tangs and Dops

These two tangs are for holding the diamond in the bottom position, which allows the cutter to place the 8 main pavilion facets.  The top tang is manual positioning and the bottom tang is automatic positioning

Here you see the diamond set in the bottom tang and being measured for accurate angle.

Here you see the diamonds on the left  being cut in bottom position.  Note that the dop is holding the diamond by the girdle edge.  The diamond on the right is being cut in top position or crown.  Note that the diamond is being held with pressure on the table of the diamond.

The top tang is for cutting the girdle of the diamond and the bottom tang is for cutting the crown of the diamond.

Here we are measuring the angle of the crown main facet.

These tangs are used with dops the are on copper stalks, to make an adjustment with a dop on a copper stalk you simply bend the wire.  On our other dop and tangs we make an adjustment by turning a knob on the dop.  The top tang is for cutting and polishing the table or making the culet.  The wooden tang is the first tang used in diamond cutting, and used a variety of dops to do the cutting.

Here are a variety of dops used with the tangs that take copper stalks.   Starting top left is a bottom dop, top dop, brass table dop, table dop and a girdle dop.  A cutter needs the variety of dops to cut a diamond,  there are also dops for certain shapes of diamonds.  The dops for pear, marquise and emerald cuts have different holding ability to help produce the finished shape.

These are the measuring devices that we use to produce the finished diamond.  Starting at the top left we have a girdle marker this allows all facets to meet at the same point in the girdle, a 90 degree guage, a 41 degree gauge, an emerald cut gauge, star emerald cut gauge (38 to 45), crown star gauge (30 to 37), bottom gauge (41 to 42), and the butterfly bottom gauge (39 to 42).

All this equipment is used to produce one thing and that’s BEAUTY.

Send mail to gary@gem-info.com with questions or comments.

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THE DIAMOND DIVER

Precision Gold & Diamond Dredge-Wyatt Yeager

Bering Sea Gold Dredging

Over the past two years we have been inundated with Emails and calls concerning dredging in the Bering Sea. With the obvious media attention and current economic situation, Alaska is a hard place to ignore especially if you are a displaced California miner. The Bering Sea beach placers can be a lucrative prospect with the biggest downside being an average 30 day season due to weather and ocean conditions. We have compiled our field notes, experience and equipment design from the past 40 years of Alaskan dredging to aid you. I’m going to make the assumption that you are a competent dredger and that you have a working knowledge of dredges. Outfitting a dredging operation for Alaska can be a daunting task. You most likely have studied numerous geologic reports, read everything online that you could find and of course watched the television reality shows. But the question remains. What do I need to be successful? Before we get into the fine details you should ask yourself a few questions:

 1) Can I risk the time and capital of a project of this scope?
 2) Am I physically and mentally healthy to endure the extremely hard and tedious labor?
 3) Do I have the tenacity and perseverance to continue with the project even if the mineral find is small?
 4) Last but most important, am I undertaking this venture as a mining operation or a get rich quick scheme?

If you answered “yes” to the above mentioned questions than you have made the rational decision to go ahead a form a realistic mining plan. To fully try and help you, I must approach the exploration plan as if it was researched by our company. Notice I used the term “exploration plan” instead of mining plan. The biggest mistake we see are individuals who choose to stay in one spot hoping to eventually hit the pay streak.  In the Bering Sea if you don’t see gold after running one ton of material move on to the next location. This venture is a business, therefore run it like a business. Common business sense while dredging dictates that every 12” of overburden you take off you lose $100 per hour in doing so. Four feet of sand overburden equals $400 loss. Dredging the Alaskan offshore placer deposits is a straight forward concept. The more gravel you process in the right area, the more gold you will produce. When planning your operation the key component is logistics, logistics, logistics. Our dredging operations take us to some of the most remote regions of Africa and the Amazon. Logistics can be a nightmare and must be planned for. Nome and the Alaskan frontier are no different. If you are prepared to invest a substantial amount of money in your project than it makes sense to fly to Nome and observe a dredging season before you place a single dredge in the water. You should diligently research the price of diesel, living costs including food, transport and berthing fees.  Ask questions of the seasoned miners and pay close attention to how many working weather days occur.  

Dredge
The dredge component of your operation can either be the most daunting challenge or the easiest. In our opinion, when designing or buying a dredge keep it simple. Electronics, motors, gadgets and lack of spares are the major factors in dredge shutdown. If you are using an open platform dredge without an enclosure keep your electronics to a minimum. The smallest hose we would use is an 8” diameter hose with a 10” being the norm. In the ocean we are not so much concerned about the rock size but the suction lift of the hose. The 8-10” hose readily sucks the gravel with less of the need for using a pry bar, compared to the smaller 6” hose. The downside to using bigger hoses is the restriction in flex. Effort is needed to move the bigger hoses underwater but can be helped by attaching your hose to floating buoys or by putting your hose through inflated inner tubes to lessen the weight

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Recovery
Although it is the standard recovery system for Nome, sluices are not the choice for optimum recovery. If you can imagine for a moment the typical gold recovery circuit and the ideal recovery conditions it would be similar to a land based recovery model. As the material enters into the scrubber it is effectively cleaned and sized. The concept is to have your cleaned fractions go to the proper recovery system. For instance you would not want your ½ inch material mixed with your ⅛ inch material going into your mineral jigs, sluices or centrifuge. The different sized material would collide and interrupt the settling pattern of the gold we are trying for. Yet, this is precisely the methods currently used. The ideal recovery solution at sea would be for the material to:

• slow down after exit from the taper
• settle and classify itself
• transfer to individual recovery zones

The concept might sound impossible especially with the rolling sea conditions, absence of mineral jigs or centrifuges and a small dredge platform but fortunately we have implemented these basic recovery techniques and so far are they working well. Essentially how the system works is as the material exits the taper it should flow over a static double deck screener. We use a top screen of ¼ inch and a bottom screen of ⅛ inch. The screener is set an angle so the oversize material flows out with gravity.  Each screen has a collection chute so the fractions go to separate holding bins. At this point the dredger has a choice to either collect and save the fines to process on land or to process on deck. On deck processing is the preferred method since most dredgers don’t have the floatation capacity and space to hold two tons of material. Since the fines are small we have a small submersible slurry pump in each bin that conveys the material to the proper recovery unit. Depending on the size of your dredge the recovery units can be volume controlled sluices or for us we use a system of small lidded jigs and a centrifuge. By all means our dredges are not starter units. I am currently designing a similar on-deck dredge processing unit for South America so I will hopefully have a few pictures of the fabrication process to share.
 
Wyatt Yeager MSc
wyattyeager@gmail.com

Gem Hunt: Travel Channel

I have to say that I am pleasantly surprised after watching the first three episodes of Gem Hunt  http://www.travelchannel.com/tv-shows/gem-hunt produced by the Travel Channel. I really can't stand to watch the mock drama of most of the current mining shows so I was happy to see more "truth" of the business with the Gem Hunt crew. Don't get me wrong there is a little bit of drama but nothing you won't be able to stomach. If you haven't tuned in essentially you have a trio of people with different backgrounds trying to buy gemstones as close to the source as possible to turn a profit later. I get nostalgic having sat in the same cafes and dealt with the same dealers as the Gem Hunt folks. What they show is pretty close to what happens in a gem deal. Any buyers out there want to chime in with your experiences or views about the show?

Wyatt Yeager

The Pan-American Mineral Jig by Wyatt Yeager

The Pan-American Mineral Jig: Building a Duplex Round Jig

 The modern mineral jig or gravity concentrators have their foundation firmly rooted in ancient history and are considered to be one of the oldest mechanical device designed specifically to recover heavy minerals from lighter gangue material. During the development of the Wilfley table in the 1890’s to the innovative and successful flotation techniques of the 1940’s mineral jigs fell in popularity. The earliest mention of jigging was by Agricola in his famous 1556 printing of De Re Metallica. He noted that circular sieves were submerged in water while the operator utilized an up and down pumping action to pulse the material through the screen itself. Currently, almost 500 years later this hand jigging method is still employed and is the standard method for most alluvial diamond mining prospecting and final concentrate cleanup in Africa and South America. You can see modern hand jigging machines such as the Bushman Jig or “Diggers Dream” popular in South Africa. Over the past 150 years many variants of the mineral jig were created but it is the author’s opinion that the last 50 years has seen an increase in the actual engineering of highly efficient jigs. Mineral jig principles and theory are widely published in mineral processing journals and throughout the internet so I will not bother discussing the science behind gravity concentration. Excellent information can be found on page 204,

 http://books.google.com/booksid=MDiZQCSBENMC&pg=PA204&lpg=PA204&dq=mineral+jigs&source=bl&ots=2KIXnA16k1&sig=hYlf5T8VTtaFNTdRMpynIMukeoU&hl=en&sa=X&ei=pUHwUtijAcbXyAGZz4HABA&ved=0CD4Q6AEwAzgK#v=onepage&q=mineral%20jigs&f=false

What the information lacks is the instruction and knowledge pertaining to the operation of jigs. In the mineral processing world the jig is one of my favorite pieces of recovery equipment. In my operations the combination of jigs and the dredge is a match made in heaven. After WWII jigs fell out of favor (in the metallic mining scene, not gemstones) for the simple reason that flotation techniques were all the rage. It was a simple process with a high recovery ratio. Of course during those years they didn’t know or didn’t care about the harmful chemicals used in the flotation process. After 30 years of stricter environmental laws causing increased awareness and costs in the process, usage of flotation cells sharply declined. Thus, the reemergence of interest in the jig around the 1960’s in places like Malaysia, the Yukon and Brazil. In fact the creation of the circular or round jig for the Malaysian tin fields brought recovery and profit to an all-time high. Every mine operator should love jigs. Why do you ask? Because jigs are user friendly, cheap, environmentally approved and have a recovery of up to 95%. This article deals with the creation and use of mineral jigs for the recovery of diamonds and other gemstones. I thought it would be interesting to show a pictorial timeline of a Pan-American style circular jig being fabricated for the famous alluvial diamond fields in Kono, Sierra Leone. I would like to thank Savana Mining Equipment for sharing their photos.

 

You can watch the round jig being tested here:

 Over the past 40 years my family has used every style of jig imaginable. For diamond recovery we prefer the circular jig over the standard 42x42 square jig. Round jigs sacrifice a tiny bit of throughput compared to the square jig but the recovery factors of the circular jig make up for it. We actually use a combination of both types of jig shapes in some of our operations. The circular jig has also proved an essential design aspect when a jig is needed for mounting on a dredge platform that rides on river current or ocean waves. Over time we have preferred to use a hydraulic action seen here: 

For more information on the saw tooth pulse pattern read page 18 here

http://www.conservation.ca.gov/cgs/geologic_resources/gold/Documents/SP87.pdf

 I would like to note that the only piece of equipment in my opinion that might rival the jig in alluvial stone recovery is the diamond stir pan popular in South Africa but that’s another article. Please feel free to email with any questions or comments you might have and please, don’t let friends buy Chinese made mining equipment ;)

 Wyatt Yeager Msc
 wyattyeager@gmail.com