BAUXITE 267 



Mexico, but they are too limited in extent, and arc too far 

 from transportation facilities, or else contain too many im- 

 purities to be of value commercially. Arranged in the order 

 of their outputs, Georgia, Alabama, and Arkansas furnish 

 the total production of the United States. 



The mining of the ore in this country is of comparatively 

 recent inception, and, quite naturally, it has not reached 

 a high state of efficienc^^ The mines are irregular holes dug 

 in the hillsides, with deep, open drainage ditches leading from 

 them. Below the surface the ore is sufhciently soft to be 

 removed with pick and gad, which renders the extraction 

 easy and lessens the cost of production. For a high grade 

 product, however, the uneven quality of the ore makes neces- 

 sary a sorting by hand or by screens. Screen sorting is gen- 

 erally preferred to hand sorting when the character of the 

 ore will admit of the use of the screen. During the sorting 

 process, when clay is mixed with the bauxite, a common log 

 washer is occasionally used to separate it. The sorted prod- 

 uct is then dried in the air or in kilns or furnaces prior to 

 its shipment to market. In this process very satisfactory 

 results have recently been secured from the use of furnaces 

 of the revolving cylindrical type. 



Refining was formerly done almost exclusively in Pennsyl- 

 vania and New York, but recently new refining plants have 

 been erected at Bauxite, in Saline county, Ark., and near 

 East St. Louis, in St. Clair county, 111. These plants are 

 equipped with modern machinery, and hand labor has been 

 superceded wherever practicable. 



France produces three varities of bauxite: The white 

 of Herault; the pale of Baux and other localities of southern 

 France; and the red, which contains a large proportion of 

 iron oxide, and which is also found in several places in southern 

 France. Of these, the white variety is the purest, containing 

 from 65 to 74 per cent of alumina, from 0.25 to 3 per cent of 

 ferric oxide, and from 12 to 18 per cent of silica. Thus it 

 is comparatively free from iron oxide but contains a relatively 

 large amount of silica. The most impure is the red variety, 

 which contains from 50 to 62 per cent of alumina, from 24 to 

 28 per cent of ferric oxide, which imparts the red color, and 



