United States Earthquakes, 1937 (open access)

United States Earthquakes, 1937

Report discussing earthquake activity in the United States during 1937. The report is broken down by regions and has sections for specific earthquakes.
Date: 1937
Creator: unknown
System: The UNT Digital Library
Recovery of Zinc from Low-Grade and Complex Ores (open access)

Recovery of Zinc from Low-Grade and Complex Ores

From Introduction: "Vocalization in retorts has been, until recently, the only commercial process of producing spelter, hence the zinc mine operators have had to meet the terms of the zinc mine operators have had to meet the terms of the zinc smelters in regard to the following requirements: (1) Minimum percentage of zinc the ore must contain; (2) the chemical combination of the zinc in the ore; (3) the proportion present of those elements that interfere with the successful recovery of the zinc when the ore is retorted. As stated previously, and as will be shown later, a large part of the valuable mineral content of the ore is lost in effecting this concentration. As a result of the other requirements that have to be met in zinc smelting, much zinc is lost in the mining and milling of zinc ore."
Date: 1919
Creator: Lyon, Dorsey A. & Ralston, Oliver C.
System: The UNT Digital Library