Belt Conveyor Design

Idlers: Due to the efforts of the Conveyor Equipment Manufacturers Association, the basic idler elements—idler roll wall thickness, bearing sizes and shaft sizes—have been standardized into classes. There is also a substantial dimensional commonality as well. Belting: Again, the rubber manufacturers have standardized, either by agreement through industry associations, or by following the leader and … Read more

Wet High Intensity Magnetic Separation

WHIM is the short acronym for Wet High Intensity Magnetic Separation. At present, most U.S. iron raw materials are produced from magnetic taconites, which are ground to a nominal minus 270 mesh (53 micrometers), beneficiated by wet low-intensity magnetic separation, and pelletized. The taconite ore bodies generally contain 19 to 25 percent magnetic iron, defined as iron … Read more

Control Water Flow during Shaft Sinking

The importance of controlling water inflow during shaft development has been well known to those faced with the problem. Depending on the amount, temperature, and quality of the water, the extra costs of working in wet conditions can easily be several times that for the same work under dry conditions. I have heard estimates of … Read more

Water Clarification by Flocculation

The chemicals involved in the work of this paper utilize a combination of mechanisms: charge effect neutralization and polymer bridging. There are a number of trends in the results that support this dual mechanism. The slow settling rate and insensitivity of changes in coagulant concentration are the typical effects of compounds used for charge neutralization. … Read more

Acidic Mine Tailing Neutralisation – Vegetation

Field tests on 20-year-old acidic copper tailing showed that after treatment with combinations of dolomitic lime, limerock, fertilizers, and/or sewage sludge, vegetation can be successfully established. Plant coverages, 4 years after seeding, ranged from 30 to 80 percent, even though neutralization of the acidic tailing with either lime or limerock was only partially effective. Chemical … Read more

Zinc Electrowinning & Zinc Cathodes

Commercial production of zinc by electrolysis began in 1881 following a patent by Letrange of France. The process has come down to the present day essentially unchanged and consists of three basic steps: Leaching of roasted zinc concentrates in dilute H2SO4; for example, ZnO + H2SO4 → ZnSO4 + H2O. Purification of the resulting zinc sulfate … Read more

Titanium Oxide or Titania Pigment by Ilmenite

Titanium dioxide or titania pigment is prepared commercially from ilmenite, an iron-titanium oxide mineral, by the sulfate process. Ilmenite is digested with H2SO4 to yield a titanium sulfate solution. Subsequently, the solution is hydrolyzed to yield a hydrous titania precipitate that is calcined to produce pigment. A major problem associated with the process is the … Read more

Structural Analysis of Grinding Mill Shells

Accurate modeling of structures by finite elements requires not only that the user estimate the load paths, and areas of stress concentrations or rapid variations, in a structure, but also that he realize the modeling idiosyncracies of each element he is working with. He needs to know limitations in displacement function assumptions, aspect ratios, angles, … Read more

Belt Conveyor Reclaim Tunnels

Whenever the material and soil conditions permit its use, a belt conveyor in a reclaim tunnel is the most economical reclaim device due to its very limited manpower requirements and utilization of gravity to make the ore flow to the feeder opening. This dependence on material flow limits the belt conveyor in a reclaim tunnel … Read more