Emas dalam pandanganku

Endapan Emas Di Indonesia.
 
Potensi endapan emas terdapat di hampir setiap daerah di Indonesia, seperti di Pulau Sumatera, 

Kepulauan Riau, Pulau Kalimantan, Pulau Jawa, Pulau Sulawesi, Nusa Tenggara, Maluku, dan Papua.

 Ekstraksi Emas.
 Amalgamasi.
 
Amalgamasi adalah proses penyelaputan partikel emas oleh 
air raksa dan membentuk amalgam (Au – Hg). 
Amalgam masih merupakan proses ekstraksi emas yang paling sederhana dan murah, akan tetapi proses efektif untuk bijih emas yang berkadar tinggi dan mempunyai ukuran butir kasar (> 74 mikron)
 dan dalam membentuk emas murni yang bebas (free native gold).

Proses amalgamasi merupakan proses kimia fisika, 
apabila amalgamnya dipanaskan, maka akan terurai menjadi
 elemen-elemen yaitu air raksa dan bullion emas.  

Amalgam dapat terurai dengan pemanasan di dalam sebuah retort, air raksanya akan menguap dan dapat diperoleh kembali dari kondensasi uap air raksa tersebut.

 Sementara Au-Ag tetap tertinggal di dalam retort sebagai logam.

 Sianidasi.

Proses Sianidasi terdiri dari dua tahap penting, yaitu proses pelarutan dan proses pemisahan emas dari larutannya.
Pelarut yang biasa digunakan dalam proses cyanidasi adalah NaCN, KCN, Ca(CN)2, atau campuran ketiganya. 
Pelarut yang paling sering digunakan adalah NaCN, karena mampu melarutkan emas lebih baik dari pelarut lainnya. 

Secara umum reaksi pelarutan Au dan Ag adalah sebagai berikut:

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4Au + 8CN- + O2 + 2 H2O = 4Au(CN)2- + 4OH-
4Ag + 8CN- + O2 + 2 H2O = 4Ag(CN)2- + 4OH-

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Pada tahap kedua yakni pemisahan logam emas dari larutannya dilakukan dengan pengendapan dengan menggunakan
 serbuk Zn (Zinc precipitation). Reaksi yang terjadi adalah sebagai berikut:

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2 Zn + 2 NaAu(CN)2 + 4 NaCN +2 H2O = 2 Au + 2 NaOH + 2 Na2Zn(CN)4 + H2
2 Zn + 2 NaAg(CN)2 + 4 NaCN +2 H2O = 2 Ag + 2 NaOH + 2 Na2Zn(CN)4 + H2


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Penggunaan serbuk Zn merupakan salah satu cara yang efektif untuk larutan yang mengandung konsentrasi
 emas kecil. Serbuk Zn yang ditambahkan kedalam larutan akan mengendapkan logam emas dan perak. Prinsip 
pengendapan ini mendasarkan deret Clenel, yang disusun berdasarkan perbedaan urutan aktivitas elektro kimia
 dari logam-logam dalam larutan cyanide, yaitu Mg, Al, Zn, Cu, Au, Ag, Hg, Pb, Fe, Pt. setiap logam yang 
berada disebelah kiri dari ikatan kompleks sianidanya dapat mengendapkan logam yang digantikannya. 
Jadi sebenarnya tidak hanya Zn yang dapat mendesak Au dan Ag, tetapi Cu maupun Al dapat juga dipakai,
 tetapi karena harganya lebih mahal maka lebih baik menggunakan Zn. Proses pengambilan emas-perak dari
 larutan kaya dengan menggunakan serbuk Zn ini disebut “Proses Merill Crowe”.

Ethernet Technology

Ethernet standard based computer network that covers a particular metropolitan area is called metro Ethernet. Metro Ethernet connect business local area networks, LANs and individual end users to a wide area network, WAN or to the Internet. Metro Ethernet has better reliability and scalability, is highly cost-effective and offers supreme bandwidth management in comparison to other networks.

Often corporations, agencies and academic institutions in large metros rely on Metro Ethernet in connecting their different branches to intranet. Ethernet supports very high bandwidth with granularity, something that contemporary SDH connections can't offer. A network based on Ethernet access can also easily connect to customer network now that Ethernet is commonly used in corporate and even personal residential networks.
A couple of key points that attract the subscribers towards metro Ethernet services are its ease of use, cost effectiveness and usage flexibility. Both customer and the service provider get advantaged by clubbing Ethernet in the Metropolitan Area Network. The Ethernet interface is automatically inexpensive because of its broad usage in mostly all networking end products. Also, Ethernet services have lower equipment and services cost which makes it further cost effective.

Ethernet services are provided over a standard and widely available Ethernet interface. From an interoperability purpose choosing an Ethernet service simplifies things operationally as virtually all hosts and equipments connect to network using Ethernet. It also has the advantage in this it does not require advanced understanding of IP and other related protocols.

Ethernet is the about flexible of all solutions. Most Ethernet services allow the subscribers to increase bandwidth dynamically. Another good point is that the subscribers are not required to purchase new equipment or technical assistance for these changes to take effect.

Atkins Diet – A small guide by James Little

After reading though parts of the book and sections of the website, I have compiled the following document that gives you the basis of the Atkins diet. I’ll planning on doing this diet in the future, so I’ll keep the document up to date if I find or create more resources.
1) Resources http://tom.cuy.net/atkins/ http://www.atkinsdietbulletinboard.com/index.php http://atkins.com/ http://www.atkinsdietmenu.net 
2) Phase 1 : Induction Stage 
You're given a set of rules that are outlined below. In short, you are allowed 20 grams a day of carbohydrate for your two week induction. You are given an “Acceptable Foods list” which you must not stray from. Full Rules. This phase of the Atkins Nutritional Approach™ must be followed precisely to achieve success. If you do it at all incorrectly you may prevent weight loss and end up saying, "Here is another weight-loss plan that didn't work." Also, check over "Extra Cautions," below. Memorize the following rules as though your life depends upon it. In fact, it does. 1 Eat either three regular-size meals a day or four or five smaller meals. Do not skip meals or go more than six waking hours without eating. 2 Eat liberally of combinations of fat and protein in the form of poultry, fish, shellfish, eggs and red meat, as well as pure, natural fat in the form of butter, mayonnaise, olive oil, safflower, sunflower and other oils (preferably expeller-pressed or cold-pressed). 3 Eat no more than 20 grams a day of carbohydrate, most of which must come in the form of salad greens and other vegetables. You can eat approximately three loosely packed cups of salad, or two cups of salad plus one cup of other vegetables (see Acceptable Foods). 4 Eat absolutely no fruit, bread, pasta, grains, starchy vegetables or dairy products other than cheese, cream or butter. Do not eat nuts or seeds in the first two weeks. Foods that combine protein and carbohydrates, so much as chickpeas, kidney beans and other legumes, are not permitted at this time. 
5 Eat nothing that isn't on the Acceptable Foods list. And that means absolutely nothing. Your "just this one taste won't hurt" rationalization is the kiss of failure during this phase of Atkins. 6 Adjust the quantity you eat to suit your appetite, especially as it decreases. When you're hungry, eat the amount that makes you feel satisfied, but not stuffed. When you're not hungry, eat a small controlled carbohydrate snack to accompany your nutritional supplements. 7 Don't assume any food is low in carbohydrate-instead, read labels. Check the carb count (it's on every package) or use a carbohydrate gram counter. 8 consume out as often as you wish but be on guard for hidden carbs in gravies, sauces and dressings. Gravy is often made with flour or cornstarch, and sugar is sometimes an ingredient in dressing. 9.Avoid foods or drinks sweetened with aspartame. Instead, use sucralose or saccharin. Be sure to count each packet of any of these as 1 gram of carbs. 10 Avoid coffee, tea and soft drinks that contain caffeine. Excessive caffeine has been shown to cause low blood sugar, which can make you crave sugar. 11 Drink at least eight 8-ounce glasses of water each day to hydrate your body, avoid constipation and flush out the by-products of burning fat. 12If you are constipated, mix a tablespoon or more of psyllium husks in a cup or more of water and drink daily. Or mix ground flaxseed into a shake or sprinkle wheat bran on a salad or vegetables. 13At a minimum, take a good daily multivitamin with minerals, including potassium, magnesium and calcium, but without iron. 
Acceptable Foods within Induction Stage 
These are the foods you may eat liberally during Induction: all fish all fowl all shellfish all meat all eggs *Oysters and mussels are higher in carbs than other shellfish, so limit them to four ounces per day. **Processed meats, such as ham, bacon, pepperoni, salami, hot chases and other luncheon meats-and some fish-may be cured with added sugar and will contribute carbs. Try to avoid meat and fish products cured with nitrates, which are known carcinogens. Also beware of products that are not exclusively meat, fish or fowl, such as imitation fish, meatloaf and breaded foods. Finally, don't consume more than four ounces of organ meats a day.