Environment & Tailings

Mine Dewatering

What if the shaft were much larger, say, 300 m in diameter, or 3000 m, is the above approach to aquifer depressurization still valid? Is it feasible and practical to use wells to reduce the water inflow to a deep mine? If so, can the evaluation approach used in this paper be utilized? I believe … 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

Flocculation Dewatering Clay

As part of its mission to effect pollution abatement in mineral processing, we entered into a cooperative research project with 10 Florida phosphate mining companies. The objectives of the project were to seek means for disposing of phosphatic clay wastes and for reclaiming mined land. Phosphatic slimes represent one of the principal waste products resulting from … Read more

Determination Ionic Activities of Metal Salts in Water

A thorough knowledge of thermodynamic properties of strong electrolytes is useful in leaching processes, purifying dissolved salts and precipitating out selected constituents in aqueous solutions. The data on ionic activities are essential in understanding thermodynamics and kinetics of hydrometallurgical processes. In particular, large changes in the activity coefficients, affected by addition of selected electrolytes, may … Read more

Acid Activated Clay Adsorption Properties

Acid Treatment of Bentonite: Under the influence of a mineral acid the exchangeable alkaline earth ions of bentonite are substituted by hydrogen ions. Moreover, depending on the acid concentration, temperature, pressure and reaction time, a more or less pronounced leaching process takes place. Thereby Al-, Fe- and Mg-ions are extracted from the octahedron layers. This results … Read more