COLLliCrioNS IN KCON'OMK! niMi,..,.^ AN'D MKlAl.i.i i>'.i 1 •>.> 



UICII IIII.L ZINC WOKKS. 



Tlicse works arc located at liich Hill, .Ia.s|H'r County, Missoiiii, and 

 smelt ores from Jopliii. They are located in ;i (M)al re;,Mon where fuel Ih 

 abundant. The works contain a kiln for dryinp: the ore, three furnaces 

 foi' roast in ft, one Uelijian and one Siemens srneltinj; Iiirnaee. The ores 

 treated ar«* the lirst and second class hiendi' sei)aratetl from the Joplin, 

 Missouri, ores, toj^^ether with some lump ore. The ore as received from 

 the separating operatn)n is «;enerally wet, an«l one-third of it is <lried 

 in the small reverberatory furnace, and mixed hot with two-thirds of 

 the wet ore, the mixture l)ein<jr dry enough for further treattuent. 



The coarse ores are crushed in a rock breaker, and then in rolls. Tlu; 

 fine ore is crushed in the rolls only. The crushed ore is roasted in two- 

 storied reverberatory furnaces having; four hearths, to remove the sul- 

 phur. A charge weighing 1,400 i>ounds is put in the furnaces every 

 12 hours through openings in the roof, and remains on each hearth ll2 

 hours, during which time it is stirred every 10 to 20 minutes. In 48 

 hours it is withdrawn from tin? lower hearth nearest the lireplace. The 

 charge loses, on roasting, about 15 per cent, of its weight. 



The roasted ore is mixed with coal slack and coke. After the ore ami 

 coal are mixed, they are slightly dami)ened, and charged into the re- 

 torts by means of around shovel or scoop. After the retort is full, a 

 half-inch bar of iron is pushed through the upper part of the charge 

 and then withdrawn, in order to leave a channel to aid the exit of the 

 zinc. 



The Belgian furnace is budt after the usual pattern with two divisions 

 having a tireplace at each end, and a common chimney. Each side has 

 seven rows of retorts with fourteen in a row. The three lower rows of 

 retorts, where the heat is greatest, are charged twice in 24 hours, while 

 the others are charged only once. lu the upper two rows blue powder 

 and other refuse from formei'smeltings are charged. 



The metal is withdrawn from the lower three rows of condensers six 

 times in 24 hours, and from the others four times. This furnace will 

 treat ab()ut 10,000 poumls of ore in 24 hours. 



The Siemens gas furnace consists of two retort chambers built upon 

 long and narrow reheating chambers, and separated from each other 

 by a thick tirebrick wall ; the back ends of the retorts rest upon this 

 dividing wall. There are three rows of forty-eight retorts each in each 

 chamber, and the furnace will treat 1,()00 pounds of ore per 24 hours. 

 The great advantage of this furnace is the greater uniformity ami 

 better control of the heat, by which means i)oorer ores nniy be smelte«l. 

 In this case second-class ores are treated very successfjilly. 



The collection taken by Mr. VI. L. Zukoski, E. M., October, 1 '<>i|.>;lin\vs 

 the ore, fuels, charges, i)roducts, and a few accessories. 



Ore. 



(1) Rlon<]»'. with Hoino cliort, cnishi-d ri'ady for tb»' roa-stors. (r>.'i421.) 

 ('2') lioastotl lilfiiilf. n Mtly to bo cbar);c<l iiiin tin- iiturts. i ."..M'^i. > 



