Chemical engineering . t frame-works in order to ensure even current distribution. Theanode on a ring at the bottom of the containing vessel,so that the cathfide can easily be slipped away and removed,and both electrodes arc held in modified Classen stands. Thepresent installation consists of thirty such unit cells, and cur-rent is supplied to them from six pairs of accumulators, eachof which supplies current to five pairs of electrodes, throughsuitable nickelin resistances. Fig. 2 is a diagram of the connections of two sets of fivepairs of electrodes. The batteries B, and B-. are conn
Chemical engineering . t frame-works in order to ensure even current distribution. Theanode on a ring at the bottom of the containing vessel,so that the cathfide can easily be slipped away and removed,and both electrodes arc held in modified Classen stands. Thepresent installation consists of thirty such unit cells, and cur-rent is supplied to them from six pairs of accumulators, eachof which supplies current to five pairs of electrodes, throughsuitable nickelin resistances. Fig. 2 is a diagram of the connections of two sets of fivepairs of electrodes. The batteries B, and B-. are connected tothe conductors L, and L,, and Ls and /... respectively. Theconductors are enclosed in wood casing, screwed down to thetable. Parallel branches run to the different electrodes, o,and f ], at and d. etc., but the main conductors Lt and Lj, andLi and L,. are insulated from each other between the sets,so as to prevent the batteries from discharging into eachther. In each one of the secondary branches there is a re-. FIG, I.—ELECTRODES sistance, /?, or Rt. etc. These resistances can be shunted atSu St, Si, etc. All the resistances are made from \o. 20nickelin wire, stretched on porcelain bobbins in front of thetable. Hence, they can easily be got at, and this is con-venient for repairs, which have frequently to be made whenelectrolytic work is carried on continuously. One gram of the alloy, dissolved in nitric acid, is used foran analysis, and a current either of amperes or else of is employed for the deposition. In the former casedeposition is complete in twelve to fifteen hours, in the latterin three hours. Electrolysis proceeds in three phases: (i)Copper deposition and ammoniacal reduction of nitric acid.(2) Ammoniacal reduction only. (3) Deposition of zinc. Aperfect separation takes place if phase (2) occupies a longtime, and is unaccompanied by metal deposition. If certainimpurities, such as arsenic or nickel, be present they must heremoved chemically.
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Keywords: ., bookcentury1900, bookdecade1900, booksubjectmetallu, bookyear1902
