/ 
PROCESSES OF REDUCTION. 139 
to improve the gold saving, but even then the extraction was lamentably low. The 
matter was made worse by the appearance of unoxidized tellurides and in a few 
years this process was entirely abandoned. 
Smelting was early recognized as a proper method of treatment for rich ores, 
and an increasing amount of such material soon found its way to the smelting 
works at Denver and Pueblo. At the present time probably one-sixtli of the 
tonnage—roughly 100,000 tons—is thus disposed of; but as ores below 4 ounces 
of gold per ton rarely go to the smelters it follows that their production is a very 
considerable part of the total output of the district. The smelting charges range 
from 86.50 upward, but vary somewhat from time to time. 
The first chlorination plant was erected by Edward Holden in 1893, and bv 
January, 1895, the first well-designed mill, of 50 tons daily capacity was completed 
at Gillett, a few miles northeast of Cripple Creek. The process employed was 
the barrel chlorination used in South Carolina and the Black Hills. 
About the same time experiments were made with the cyanide process, the 
first mill being erected at Brodie in 1892. In 1895 the Metallic Extraction Com- 
o 
pany’s mill was built near Florence and gradually enlarged to a capacity of 170 
tons per day. At that time began the struggle for supremacy between the chlori¬ 
nation and cyanide processes, from which the former appears to be emerging 
victorious. 
Another change soon began to be apparent. With the advent of improved 
railroad facilities the lower valleys were found to be better adapted for the location 
of great reduction works, Colorado Springs and Florence being the most favorable 
points selected. In 1899 there were still four plants in operation at Cripple Creek, 
but in 1903 only one mill was active, aside from two smaller plants, for direct 
cyanide work. 
In 1904 the different plants were located as follows: 
Cripple Creek: , Tons capacity. 
Economic mill (chlorination). 300 
Homestake mill (direct cyanide). 200 
Sioux Falls mill (direct cyanide). 100 
Colorado Springs: 
Portland mill (chlorination). 300 
Telluride mill, General Metals Company (chlorination). 300 
Standard mill, United States Reduction and Refining Company (chlorination). 4.50 
Florence: 
Dorcas mill (cyanide). . 1-50 
United States Reduction and Refining Company (chlorination). 400 
This makes a total capacity of over 2,200 tons, or about 800,000 tons per 
year, which considerably exceeds the greatest tonnage yet produced in the district. 
The charges of the cyanide and chlorination mills vary with the tenor of the 
ore. The cheapest schedule issued in 1904 ranged from 85.50 per ton for half¬ 
ounce ore to 89 per ton for 3- to 5-ounce ore, the freight charges from mine to mill 
being included. Recently, however, it is understood that these prices have been 
raised. The schedule in 1903 varied from 87.50 for half-ounce ore to 813.50 for 
5-ounce ore. 
