3U 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



[NoVEJIBEB, 



nace • bv wliicli the scoria or slag is fused, the reduced zinc vola- 

 tilised, iind the vapours condensed, and conducted into a receiver 

 of a ])ceuliar form, situated over the mouth of the furnace, and 

 heated by tlie gases therefrom. 



Fig. I represents a vertical section of the furnace, taken in a 

 line "ith tlie tuyere holes ; fig. 2 is an elevation of the same, on 

 that side where the aperture for charging is situated, the con- 

 densers being shown in section ; and fig. 3 is an elevation of the 

 furnace, on the side where the tuyere pipes are situated, a, is the 

 aperture or channel for charging; a*, is a sliding partition ; b, the 

 outer door or cover for closing the charging channel ; c, o, c, are 

 apertures, through which the scoria runs; rf, is an opening between 

 the liody of the furnace and the receiver e, the lower part of which 

 is formed by the cover or partition/, at the top of the furnace; 

 and the upper part by another cover/', larger than the lower one, 

 forming a kind of channel, in which the zinc is condensed, g, g, 

 (fig. 2) are openings for the escape of the gases ; It, is an hydraulic 

 main ; B, is the tuyere or blast-pipe ; and /c, k, <ire openings for 

 extracting the zinc and any extraneous matters ; these openings 

 are luted every time the metal, &c., is run off. 



Fig. 2. 



Fig. 3. 



The mode of operation is as follows :— The furnace having been 

 heated to the required temperature by the combustion of fuel 

 alone, a charge of zinc ore, either in the state of oxide, carbonate, 

 or silicate, mixed with any suitable flux, according to the nature 

 of the ore, is introduced into the charging aperture a, between 

 the sliding-plate a*, and the door b ; so that by drawing out the 

 slide «*, the charge will descend by its own gravity into the body 

 of the furnace, without allowing the gases to escape through the 

 charging aperture b. The charge thus falls upon a layer of incan- 

 descent fue , rising to a certain height above the tuyere B. A 

 layer of fuel is then poured upon the ore, then another charge of 

 ore, and so on alternately until the furnace is full ; and it is to be 



Fig. 4. 



Fig. 6. 



Fig. 6. 



The zinc is volatilised by the heat, and the scoria falls into the 

 lower part of the furnace, and is run out at tlie ai)ertures c, c, c. 

 The volatilised zinc is carried nff with tlie gases arising from com- 

 bustion, and passes through the opening d, into the receiver e, 

 above. The gases from the fire-place escape through the openings 

 g ; and as these latter might carry off particles of zinc with them, 

 they are passed through an hydraulic main A, before being allowed 

 to escape into the atmosphere, By this means all solid matters 

 are retained, and the zinc, together with any dust or extraneous 

 particles, is extracted through the openings h: When the ore to 

 be operated upon is in a comminuted state, it is advisable to make 

 it up into a paste, together with the flux, by the addition of water, 

 so tliat it may be charged in pieces of such size as not to pass 

 through the fuel. Zinc ore is often mixed with sulphuret of lead, 

 and by this mode of operation the zinc is obtained by volatilization, 

 and the lead by fusion (this latter running to the bottom of the 

 furnace below the scoria), if, by pre\ious roasting, a portion of 

 the sulphur has been driven off from the ore. 



The second part of the invention consists in a novel construc- 

 tion of apparatus for the manufacture of oxide of zinc. Fig. i 

 is a vertical section of the furnace, and of the chamber for the 

 reception of the oxide of zinc ; fig. 5 is a horizontal section of 

 the furnace, taken in the line c, d, of fig. t ; and fig. 6 is a vertical 

 section, taken in the line a, 6, of fig. 4. a, a, are the retorts or 

 subliming-pots (of which there may be any convenient number), 

 placed in the sole of the furnace ; B, b, are the covers of the re- 

 torts, which are perforated; c, is the door of the oxidising- 

 chamber ; f, upper flue, through which the gases and other pro- 

 ducts of combustion pass from the fire-place to the chimney; k, k, 

 are vessels for receiving the zinc, in case of rupture of the retorts 

 or pots, in which case the liquid metal would run down on the floor 

 Q, a, and from thence into these vessels ; L, is the flue or chimney 

 of the furnace ; m,m, fig. 6, are vertical flues in the wall, for the 

 passage of the waste gases of combustion ; n, is a top partition, 

 dividing the oxidising-chamber e, from the horizontal flue p ; — 

 M, M, is a chamber for receiving the oxide of zinc ; o, a chimney 

 for creating a draught, and thus drawing the oxide of zinc, toge- 

 ther with air and gases, through the chamber M, and alternately 

 over and under the upper and lower partitions p, and Q. There 

 may be any number of these partitions, according to the size of 

 the apparatus, and the quantitv of oxide to be manufactured, g", 

 is a wire-cloth, or other suitable sifting partition, at the end of the 

 chamber m, for retaining the oxide of zinc, and, at the same time, 

 allowing the air and gases to pass through to the chimney o. It 

 will be seen that the furnace is divided into three separate cham- 

 bers or compartments; the lower one, which may properly be 

 called the furnace or lieating-flue, contains the retorts a, which are 

 charged with the zinc to be operated upon. The volatilised zinc 

 escapes through the orifices in the covers b, of the retorts, and 

 enters the middle or oxidising-chamber e. The zinc vapour is 

 oxidised and forced through the chamber ji, either by means of a 

 blower or by the draught created by the chimney o, at the end of 

 the chamber m. Tlie upper compartment F, is nothing more than 

 a narrow channel or flue, for the passage of the smoke and gases 

 from the fire-place to the chimney l. These gases heat the dome 

 N, and thus keep the oxidising-chamber at a sufficiently high tem- 

 perature to burn the zinc vapours with facility and rapidity. The 

 partitions p, and q, in tlie chamber si, are for the purpose of check- 

 ing the power of the current and facilitating the deposit of the 

 oxide in the chamber m, from whence it is withdrawn by means of 

 openings at the sides. 



The patentee, in conclusion, states that he is aware of oxide of 

 zinc having been heretofore obtained by distillation, and bringing 

 the volatilised metal into contact with atmospheric oxygen in an 

 oxidising-chamber ; he does not, therefore, intend to claim, gene- 

 rally, producing oxide of zinc in this manner ; but he claims, 

 firstly — obtaining metallic zinc in the manner and by means of the 

 app.iratus above set forth and described, or any mere modification 

 thereof. And, secondly — producing oxide of zinc by distilling the 

 metal, or matters containing metal, in subliming-pots or vessels, 

 furnished with perforated covers, through which the volatilised 

 metal may issue into an oxidising-chamber, where it is met or 

 brought into contact with tlie oxygen of the atmosphere, and 

 becomes converted into oxide of zinc. 



replenished in the same manner, when the charge sinks below a 

 certain depth, which can be easily ascertained by experience. 



