Electrochemical and metallurgical industry . d using a silver methyl-sul-phate s<jlution. These methods all have in common the characteristic of part-ir-K ?»! retinmg btdlion free from gold and tellurium at onethe deposited silver being melted and poured into.;out any further refining, as in the sulphuric acid pro-cess. Silver placed in the tanks as anodes is not handled imtiltaken out as refined silver, whereas in the acid method thesilver either in solution or as cement must be transferred several limes with the aid of siphons, steam, etc., before it isin a condition to be melted. For the
Electrochemical and metallurgical industry . d using a silver methyl-sul-phate s<jlution. These methods all have in common the characteristic of part-ir-K ?»! retinmg btdlion free from gold and tellurium at onethe deposited silver being melted and poured into.;out any further refining, as in the sulphuric acid pro-cess. Silver placed in the tanks as anodes is not handled imtiltaken out as refined silver, whereas in the acid method thesilver either in solution or as cement must be transferred several limes with the aid of siphons, steam, etc., before it isin a condition to be melted. For these reasons it is possible tooperate an electrolytic parting plant with a higher degree ofneatness and cleanliness (such as the value of the materialtreated requires) than is possible with acid parting. A |)arting plant using the Ralbach method is simple in con-struction and operation. Fig. 2 shows the cross-section of alank. The cathode is made of Ki-ich .^cheson graphite slabsfitted to the bottom. Two silver contact pieces rest res|)ec-. tively on the bullion to be parted and the graphite slabs. Bul-lion cast in thin, stjuare slabs is contained in a cloth case, whichis supported on a wooden frame suspended over the tank. Thegold slimes accunnilate on the under side of the bullion, be-tween it and the cathode, increasing the resistance as the opera-tion continues. Each tank has a cathode surface of 8 squarefeet and a current density of 20 to 25 amps, per square foot isused. The voltage averages per tank, and an averageamivere efficiency of 93 per cent was obtained on a continuedrun, while occasionally an efficiency of 98 per cent was power required is watt-hours per ounce of fine silverproduced. Most of the silver is deposited on the cathode surface di-rectly under the anode, and the reduction of the distance be-tween anode and cathode is limited by the space necessary toreach in and remove it, which has to be done frequently onaccount of the silver bridgi
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Keywords: ., bookcentury1900, bookdecade1900, booksubje, booksubjectmetallurgy
