أريد تقليل درجة الإنصهار للذهب
- بادئ الموضوع sicosad
- تاريخ البدء
waleed_hamoda
Well-Known Member
باستخدام سبيكة الرصاص والقصدير
إستخدم المؤلف (وهو مؤلف كتاب العرب وكيمياء الذهب). والكلام دا موجود فى الموقع دا
هنا باسم الله
هذه السبيكة لصهر الذهب ذي درجة الإنصهار العالية. فهذه السبيكة المنصهرة من شأنها أن تُخّفِضَ درجة إنصهار الذهب الأمر الذي يوفّر على الكيميائي الجهد والوقود والوقت
إستخدم المؤلف (وهو مؤلف كتاب العرب وكيمياء الذهب). والكلام دا موجود فى الموقع دا
هنا باسم الله
هذه السبيكة لصهر الذهب ذي درجة الإنصهار العالية. فهذه السبيكة المنصهرة من شأنها أن تُخّفِضَ درجة إنصهار الذهب الأمر الذي يوفّر على الكيميائي الجهد والوقود والوقت
waleed_hamoda
Well-Known Member
واللهى يا أخى لو هتشتغل فى مجال الدهب والمصوغات والذى منه...فأنا لاقيتلك المعلومات دى
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أما يا أخى لو هتشتغل شغل كيميا فى المعمل وأبحاث وكدة فآدى المعلومات اللى أكيد هتفيدك بإذن الله
قامت هذه العملية على حقيقة علمية و هي مقدرة سيانيد البوتاسيوم او الصوديوم على اذابة الفلزات الثمينة ( الذهب و الفضة ) من خاماتهما المطحونة دون اي تأثير على بقية الخام او الشوائب الاخرى طبقا لمعادلة التفاعل التالية :
xx4Au+8NaCN+2H2O+O2----->4Na[Au(CN)2]+x4NaOH
تتم الاذابة في عدد من الاحواض المتتالية و عند الانتهاء من اذابة الفلز يفصل المحلول الغني بالذهب عن بقية المواد غير المذابةمن خلال احدى عمليات الفصل المختلفة ، و عندئذ يضاف الزنك ( في صورة مسحوق) الى المحلول الغني بالفلز ، حيث يتم ترسيب الذهب طبقا للمعادلة التالية :
x2Na[Au(CN)2]+Zn----->Na2[Zn(CN)4]+x2Au
The following series of images show how a bangle is manufactured using a clients gold.
It does not matter if the gold is of different carats, it all goes into the crucible to be heated. We do not melt down white gold in with yellow or red gold. This is due to the alloys contained within the white gold causing the ingot to crack when it is rolled and worked, making the ingot unusable.
The gold continues to be heated and powdered flux added to clear away any impurities from the surface of the gold. The impurities are then trapped within the flux which then coats the crucible. When the gold is ready to be poured it looks like very shiny and fluid.
The torch is still playing on the gold so the temperature does not drop causing the gold to solidify. The crucible is then lifted and the gold poured steadily into an ingot mould which has been coated with oil which has been burned off leaving a carbon film which helps the finish of the ingot.
The gold is rolled through a rolling machine (similar to an old fashioned mangle) which shapes the ingot. After several passes the gold is annealed (softened) by heating to a dull red colour and left to cool. The gold is then rolled through the next set of grooves, getting smaller, and annealed. The process is repeated until the ingot is the required section.
Once the required section has been achieved the gold is annealed and then one end is placed into a vice. Pliers are used to hold the other end and the gold twisted until the required pattern has been achieved. If it gets harder to twist then the gold is annealed again.
The gold in this picture is almost black in colour. This is due to the oxides on the surface due to the constant annealing. The oxides are removed by quenching the gold in sulphuric acid.
The bangle is measured for length (we manufacture each bangle to the clients individual hand measurements), then turned round and cut.
Once the bangle has been soldered, using hallmarking quality solder of the correct carat the joint is carefully filed to ensure there is no interuption in the pattern. Emery paper is then used to get rid of the file marks to achieve a uniform finish
The bangle is then hand polished using a rough tripoli polish to obtain a semi matt finish. This polish removes the marks made by the emery paper.
The final polish is achieved by using a rouge polish on the polishing mops. This imparts a professional highly reflective finish with no surface marks or imperfections.
The result is a bangle that is a pleasure to wear all day every day
It does not matter if the gold is of different carats, it all goes into the crucible to be heated. We do not melt down white gold in with yellow or red gold. This is due to the alloys contained within the white gold causing the ingot to crack when it is rolled and worked, making the ingot unusable.
The torch is still playing on the gold so the temperature does not drop causing the gold to solidify. The crucible is then lifted and the gold poured steadily into an ingot mould which has been coated with oil which has been burned off leaving a carbon film which helps the finish of the ingot.
The gold is rolled through a rolling machine (similar to an old fashioned mangle) which shapes the ingot. After several passes the gold is annealed (softened) by heating to a dull red colour and left to cool. The gold is then rolled through the next set of grooves, getting smaller, and annealed. The process is repeated until the ingot is the required section.
Once the required section has been achieved the gold is annealed and then one end is placed into a vice. Pliers are used to hold the other end and the gold twisted until the required pattern has been achieved. If it gets harder to twist then the gold is annealed again.
The gold in this picture is almost black in colour. This is due to the oxides on the surface due to the constant annealing. The oxides are removed by quenching the gold in sulphuric acid.
The bangle is measured for length (we manufacture each bangle to the clients individual hand measurements), then turned round and cut.
Once the bangle has been soldered, using hallmarking quality solder of the correct carat the joint is carefully filed to ensure there is no interuption in the pattern. Emery paper is then used to get rid of the file marks to achieve a uniform finish
The bangle is then hand polished using a rough tripoli polish to obtain a semi matt finish. This polish removes the marks made by the emery paper.
The final polish is achieved by using a rouge polish on the polishing mops. This imparts a professional highly reflective finish with no surface marks or imperfections.
The result is a bangle that is a pleasure to wear all day every day
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أما يا أخى لو هتشتغل شغل كيميا فى المعمل وأبحاث وكدة فآدى المعلومات اللى أكيد هتفيدك بإذن الله
- طريقة السيندة
xx4Au+8NaCN+2H2O+O2----->4Na[Au(CN)2]+x4NaOH
تتم الاذابة في عدد من الاحواض المتتالية و عند الانتهاء من اذابة الفلز يفصل المحلول الغني بالذهب عن بقية المواد غير المذابةمن خلال احدى عمليات الفصل المختلفة ، و عندئذ يضاف الزنك ( في صورة مسحوق) الى المحلول الغني بالفلز ، حيث يتم ترسيب الذهب طبقا للمعادلة التالية :
x2Na[Au(CN)2]+Zn----->Na2[Zn(CN)4]+x2Au
- لحل الذهب يلجأ الى الماء الملكي, كما ان إضافة مواد مؤكسدة لحامض كلوريد الهيدروجين مثل
- الهالوجينات, وبيروكسيد الهيدروجين او حامض الكروم يؤدي كذلك الى ذوبان الذهب .
- ايضاً يذوب الذهب في حامض السيلينيوم .
- يذوب ايضاً في محلول ثيوكبريتات الصوديوم مع الأكسجين وفي محاليل مركبات السيانيد مع العناصر القلوية .
- HNO3 و HCl يستخدمان معا لاذابة الذهب وانه لا يمكن لاحدهما اذابة الذهب دون الاخر