Depressants and Flocculants in Iron Ore Beneficiation – Starches and Starch Derivatives

This article discusses the effect of physical and chemical modifications of starches on the anionic and cationic flotation of silica from oxidized iron ores and magnetite-taconite concentrates, and the results of the interaction of starch, pH, and calcium ions on the flocculation, clarification, and filtration of iron ore slimes and magnetite- taconite tailings. Starches, particularly … Read more

How to Recover Silver from Waste Photographic Solutions

Metallic displacement-type silver recovery units are economical and practical for use by either large- or small-scale photographic processors. Most photographic processors could significantly increase their income by utilizing a unit of this type. The large-scale processor may find it advantageous to use the metallic displacement-type unit as a scavenger following an electrolytic cell. Electrolytic units … Read more

Secondary Breakage in Taconite Open Pit Mining

The mining of taconite, to provide feed for a processing plant, requires that the flow of material continue uninterrupted. This means first, that the crude must be of a size acceptable to the primary crusher in order to reduce the delays caused by plugging the crusher with chunks. Secondly, elimination of oversize in the pit … Read more

Use of Rocket Jet Burners in Quarrying of Granite

The first step in the quarrying of granite, following removal of any overburden material, involves the freeing of large blocks from the formation. For many years the use of explosives was the accepted method of obtaining these blocks. Even today there are operations where this is considered to be the most economical method even though … Read more

Priming and Boostering Anfo with Slurry Explosives

Following the wide-spread acceptance of ANFO as a useful, low cost blasting agent, studies have been made to adequately describe the physical and explosive properties of this material. As the quality of the AN blasting prill improved, reliability and sensitivity to initiation were greatly increased and many methods of priming were chosen from the standpoint … Read more

Flow of Solids in Bins

There used to be a time when bins were designed for total volume and placed in any available place of the plant. Poke holes were provided and feed was maintained by manual prodding, lancing, hammering, and by various mechanical flow-promoting devices. Little thought was given to what occurred inside the bins and why materials did … Read more

How does Cyanide Depress Pyrite – Mechanisms

Oxidation potentials have been measured in the presence of various concentrations of cyanide, ferrocyanide, and ferricyanide and ethyl xanthate at various values of pH and related to flotation response. Eh-pH diagrams are constructed and show that the formation of surface ferric ferrocyanide is probably responsible for depression when cyanide is added. Experimental Materials and Techniques … Read more

Laser Alignment Underground

Accurate and economic control of line and grade on long tunnels, large structures, excavations and waterways, has been a problem to surveyors and engineers for decades. The conventional method of surveying, incorporating a level, transit, and a number of surveying technicians, has proven, in the past, to be a very expensive and time-consuming operation. Operation … Read more

Flotation Cell Hydrodynamics

A fully-instrumented driving mechanism has been constructed to study the power, aerating and solid suspension characteristics of several laboratory flotation machines. Machines operating over normal flotation speed ranges give constant power numbers in liquid systems indicating that they operate under fully baffled turbulent flow conditions. Owing to lack of geometrical scaling, power numbers for different … Read more

Hydrochloric Acid Leaching of Iron from Aluminous Clays

Pennsylvania has ample reserves of high-alumina clays which are potential sources of alumina, but many of these clays contain large amounts of iron, which makes them unsuitable for treatment by acid processes. Of all the clay minerals tested, only gibbsite exhibits high acid solubility. Kaolinite, diaspore, and boehmite, which are the major alumina-bearing minerals in … Read more