i6 



ECONOMIC GEOLOGY, 



J. H. RAE. 

 Improvement in Voltaic Amalgamators for Gold and S 

 No. 123.932 Patonlei! fab. 20, 1872. 



view of this washer is shown in Figs. 5 and 6 of the drawing. It consists of a conical 

 tub, lined with copper, and in this tub is contained a double-walled inverted truncated 

 cone, G, which is suspended from a water-supply pipe, H, and which is perforated 

 with a number of small holes in its outer bottom and in the lower portion of its exter- 

 nal jacket, so that the water admitted through the pipe H discharges from the cone G 



in a large number of fine jets, 

 producing an upward current. 

 The washer F is placed on a 

 table, with a spout, /, extend- 

 ing over a second washer, F', 

 which is constructed like the 

 first v/asher, and the dis- 

 charge-spout I' of which ex- 

 tends over a gutter, I, lined 

 with copper. 



In using my invention I 

 first reduce the ore to a fine 

 powder, and then I introduce 

 the same, together with a 

 suitable quantity of water, 

 quicksilver, and suitable ex- 

 citing chemicals, into the 

 cylinder or cylinders A. The 

 chemicals which I use are 

 common salt, or such acids 

 which, when brought in con- 

 tact with the voltaic pile, will 

 excite a galvanic current. In 



\x»WM..^tv ^ X"^->= ^ y // ^ve^-v«T. '■^g^^'d t° t'^e quantity of 



^ quicksilver and the character 



llfo^CUx&i^ ^%:^;^____^_^^^ and quantity of the exciting 



y agent used, reference must 



always be had to the nature of the ore and to the electric affinities of the metals con- 

 tained in the ore about to be washed. After revolving the cylinder or cylinders from 

 three to four hours, the quicksilver is drawn off through the pipe or pipes d. Then 

 each cylinder is again revolved for a few minutes for the purpose of fluidizing the pulp, 

 when the man-hole plate is taken out, and the whole contents of the cylinder dis- 

 charged into the receiving-tank D, whence the pulp gradually discharges into the 

 agitating-tub E. In this tub the pulp is agitated, the amalgam being precipitated, 

 while the tailings are drawn off through either of the pipes /, according to their spe- 

 cific gravity. The amalgam which collects on the bottom of the tub is removed from 

 time to time, while the tailings pass into the first washer, F, where small particles of 



