COLLECTIONS IN ECONOMIC GEOLOGY AND METALLURGY. 67 



Flux. 



(1) Cinder from iron puddling mill. (54892.) 



Fuel. 

 (1) Coke. (54U01.) 



Intermediate products. 



(1) Pig lead, niiretined, from blast furnace smelting. (.'S4877.) 



(•2) Slag, from the outside of a pot full. (54893.) 



(15) Slag, crystallized, from the interior of a pot full. (.54890.) 



(4) Matte. (54894.) 



(5) Roasted matte. (.54899.) 

 ((5) Boasted matte. (54895.) 



Vroducis. 



(1) Nickel and cobalt matte, contains 9.8(i per cent, nickel, '.\.2'i per cent, cobalt. 

 (54921.) 



(2) rig lead, refined. (51128.) 



(3) Skimmings from the refinery. (54898.) 



THE PRODUCTION OF PIG LEAD AND WHITE PAINT AT THE LONE 



ELM WORKS. 



These works are situated at Joplin, Jasper Coauty, Missouri, 1^ 

 miles northwest of the town, and are (iounected with the St. Louis and 

 Sau Francisco Railroad by a branch track. They are shown on PL. 

 IX. The ore treated is mined in the immediate vicinity, and consists 

 essentially of galena, with some blende and chert, the galena being 

 sometimes more or less decomposed. The ore is roughly dressed at the 

 mines. A mixture of the ore with raw coal and slacked lime is charged 

 into a large Scotch hearth which is kept very hot, the object being to 

 produce as much fume as possible. The products of this operation are 

 pig lead, which is refined and sold, pasty slags containing oxidized com- 

 pounds of lead, lime, and chert, which are afterwards treated for the lead 

 they contain, and the fume. This latter is drawn off by an exhaust fan 

 through settling chambers and cooling flues, and collected in bags made 

 of unwashed wool. It is an impalpable ])0wder of a lead color, and is 

 known as blue powder. From the collecting bags it is drawn off onto 

 a brick floor. 



This material contains sufficient carbonaceous matter and unaltered 

 sulphides to burn when ignited, and burning converts it from a light 

 impalpable powder, difficult to handle, into an open, porous crust suf- 

 ficiently coherent to stand the subsequent handling. 



. This crust is next thrown upon a very hot coke tire, in a slag eye 

 furnace. This treatment gives a fume in the form of a perfectly white 

 powder, which is drawn off" and collected as before. The puritied fume 

 forms an excellent paint, and is in much demand for that purpose. 



In the slag eye furnace are also treated the pasty slags from the 

 hearth, and some carbonate of lead, locally known as '• dry bone." 



