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L&WB Badge Front
L&WB Badge Back
Maxwell Breaker L and WB Coal Co 1910
Colorado and Pikes Peak Consolidated Mining Cripple Creek
Colorado Bureau of Mines Bell Sign
  Cupel Mould.JPG - CUPEL MOULD - Brass cupel mould, 5 1/8 in. high, plunger dia. 1 1/4 in., cylinder height 1 3/8 in. and outside dia. 1 7/8 in., shown with bone-ash cupel recovered from the mill house of the Nabesna Mine, Chisana District, Valdez-Cordova Borough, Alaska by my good friend Neil Tysver(The final process of fire assaying gold and silver ore is called cupellation, the object of which is to remove base metals such as lead and copper as oxides while leaving the remaining gold and silver in a metal state called a button.  It is performed in a muffle furnace in a porous vessel called a cupel which is usually made of bone ash.  The process of manufacturing a cupel is as follows.  Finely ground bone ash is moistened with water and thoroughly kneaded so that the mass is of uniform consistency throughout and free of lumps.  The material is best worked by rubbing between the hands.  The bone ash is sufficiently wet when it coheres by gently squeezing it in the hand.  Generally, bone ash requires the addition of about one-twelfth its weight of water.  Small quantities of cupels can be made by hand in a cupel mould as shown in the pic.  This device is usually made of iron or brass, as this one, and consists of a hollow cylinder and a plunger with a concave bottom that fits in the cylinder to compress the bone ash and shape the top of the cupel.  In forming the cupel, the cylinder is filled with the moistened bone ash and the plunger is placed in the cylinder and is compressed by three or four sharp blows from a wooden mallet.  The plunger should be rotated one-half turn to free it and smooth the face of the cupel which can then be removed by carefully sliding it out of the cylinder and left to dry.  Cupels vary in size according to the weight of the lead button being cupelled.  A cupel should be capable of absorbing its own weight of molten litharge.  A cupel of 1 in. top diameter can absorb 8 grams of litharge while a 1 1/2 inch top diameter can absorb 28 grams.  See Ernest Smith, The Sampling and Assay of the Precious Metals, 1913, J. B. Lippincott Co., Philadelphia)  
Cupel Mould II
Cupel Mould Ad 1899 John Taylor & Co Catalogue
3 and 4 in Davis Anemometers
3 in Davis Anemometer Front
3 in Davis Anemometer Back

Cupel Mould | CUPEL MOULD - Brass cupel mould, 5 1/8 in. high, plunger dia. 1 1/4 in., cylinder height 1 3/8 in. and outside dia. 1 7/8 in., shown with bone-ash cupel recovered from the mill house of the Nabesna Mine, Chisana District, Valdez-Cordova Borough, Alaska by my good friend Neil Tysver (The final process of fire assaying gold and silver ore is called cupellation, the object of which is to remove base metals such as lead and copper as oxides while leaving the remaining gold and silver in a metal state called a button. It is performed in a muffle furnace in a porous vessel called a cupel which is usually made of bone ash. The process of manufacturing a cupel is as follows. Finely ground bone ash is moistened with water and thoroughly kneaded so that the mass is of uniform consistency throughout and free of lumps. The material is best worked by rubbing between the hands. The bone ash is sufficiently wet when it coheres by gently squeezing it in the hand. Generally, bone ash requires the addition of about one-twelfth its weight of water. Small quantities of cupels can be made by hand in a cupel mould as shown in the pic. This device is usually made of iron or brass, as this one, and consists of a hollow cylinder and a plunger with a concave bottom that fits in the cylinder to compress the bone ash and shape the top of the cupel. In forming the cupel, the cylinder is filled with the moistened bone ash and the plunger is placed in the cylinder and is compressed by three or four sharp blows from a wooden mallet. The plunger should be rotated one-half turn to free it and smooth the face of the cupel which can then be removed by carefully sliding it out of the cylinder and left to dry. Cupels vary in size according to the weight of the lead button being cupelled. A cupel should be capable of absorbing its own weight of molten litharge. A cupel of 1 in. top diameter can absorb 8 grams of litharge while a 1 1/2 inch top diameter can absorb 28 grams. See Ernest Smith, The Sampling and Assay of the Precious Metals, 1913, J. B. Lippincott Co., Philadelphia) Download Original Image
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