Use of Bleaching Clays in Water Purification

Bleaching clays have been used extensively in the oil-refining industries for a number of years. Their use in water purification is relatively recent and less extensive. They are frequently classified as (1) those naturally active and (2) those active after artificial activation with acid. Fuller’s earths fall within the general group of bleaching clays and … Read more

Pressure Leaching of Uranium

Early studies in the carbonate leaching of uranium ores led to the investigation of pressure leaching as a method to enhance the dissolution of the metal values in this system. The initial investigations conducted at the University of British Columbia supplemented by the work done by the group at the A.E.C. Grand Junction pilot plant, … Read more

Sphalerite Leaching Kinetic

During roast, virtually all the iron in the concentrate feed is converted into zinc ferrite which remains almost inert in the neutral-leach stage. In order to recover zinc incorporated in ZnO·Fe2O3, a follow-up treatment of the leach residue is required. Ferric chloride is one of the ideal agent for the direct leaching of sphalerite. But … Read more

Plastic Flow Under Biaxial Tension

During the course of an investigation of the plastic flow of aluminum aircraft sheet under combined loads, several problems arose in which analyses of the conditions leading to unstable plastic flow were needed. In order to provide these analyses, and in the hope of attaining a better understanding of the general problem of unstable plastic … Read more

Manganese Extraction by Carbamate

The widespread occurrence of manganese in low grade oxide and carbonate ores not amenable to mechanical concentration has led to extensive investigations of hydrometallurgical methods for producing a pure manganese compound suitable for further treatment. Manganese carbonate is the preferable compound. This product when fully crystalline and of not too fine crystal size is easily … Read more

Procedures for Determining Pelletizing Characteristics of Iron Ore Concentrates

In most routine experimental work on products and processes, methods of operation and product evaluation are established from accurately controlled laboratory tests. With particular emphasis on the pelletization of fine iron ore concentrates, standardized procedures of laboratory production and product testing have been established at Cleveland-Cliffs Iron Co. Research Laboratory at Ishpeming, Mich. A program … Read more

Kerosine Flotation

In cleaning coal it has long been recognized that methods which give excellent results for the coarser sizes may give poor or even no cleaning for the finer sizes. Effective cleaning of the fines, therefore, is usually a separate and distinct problem. For many years the problem of fines was considered of relatively minor importance. … Read more

Depolarizing Magnetite Pulps

In classification of pulps bearing magnetized ferromagnetic particles, depolarizing is of great importance. If size separation is to be effective, particles must be individual rather than in flocs. Depolarizing is also practiced in heavy medium separations in which ferrosilicon or magnetite is the medium. Properties of Ferromagnetic Materials: Experimental work, described below, has shown that … Read more

How to Test the Strength of Rocks

This paper reviews the progress made in testing the strength of rocks, ores, coal, salts, and other minerals as they are encountered in mine operations. It attempts to correlate the results of these physical measurements with technological properties more useful to the mining engineer: abrasive hardness, grindability, and behavior in comminution on one hand, and … Read more

Electrowinning

Electrowinning is defined as the cathodic deposition of metal, in this example copper, from a copper bearing solution by the passage of an electric current current using an insoluble anode. For copper the electrowinning reaction reaction is: CuSO4 + H2O ⇒ Cu + ½O2 + H2SO4 The overall reaction is the combination of two electrochemical … Read more