The nature of the reactions occurring in the distillation of zinc from its ores and the effect on the speed of these reactions due to certain variables

The reactions that occur in the metallurgy of zinc are in general well known as to the end results obtained. The zinc smelter desires a maximum recovery in a minimum time. There are certain factors that govern the fulfillment of this desire. The most important of these are TEMPERATURE, TIME, KIND OF REDUCTION MATERIAL, and THE NATURE OF THE ORE. There is much data available as to the temperatures at which these reactions go on and also there is obtainable some information as to the speed with which these reactions progress, particularly as to the length of time required for the commercial distillation. All of this information however is to a certain degree disconnected and to some extent contradictory. the lack of information particularly true as regards the time factor and the completeness of reaction at various temperatures under known conditions. The four points mentioned above, TIME, TEMPERATURE, KIND OF REDUCTION MATERIAL, and NATURE OF THE ORE are of vital importance to the zinc metallurgist for upon these factors hinge not only the capacity of his plant, because of the speed of distillation, but, also, the recovery of values --Statement of the Problem, page 1

Oils and flotation

We know that the sulphides, or minerals with a metallic lustre, can be floated either with or without oil and that the carbonates, silicates, etc., cannot be floated so readily. Why do certain oils have the power of selecting certain minerals? Why do certain oils produce froth? Why do certain oils give a watery froth? Why do some give an ephemeral froth and others a tough one? Of the thousands of oils known, only a few classes have found successful application in this new process...This leads us to the question, what property or combination of properties make oils valuable as flotation agents?--Introduction, page 5-6