Rock Drillability

Costs of boring holes in rock have always been a major item in mineral exploration, development, and extraction and in rock excavation in industries other than mining. Efforts to reduce the costs have been made by the drilling industry for many years. Rock drillability studies were started at the Twin Cities Mining Research Center in … Read more

Pure Phosphoric Acid from Hydrochloric or Sulfuric Acidulated Rock The Imi Process

The Israel Mining Industries Institute for Research and! Development has developed, during recent years, a number of new processes for fertilizer materials. Their phosphoric acid processes, however, are capable of producing an acid of far higher quality than that normally associated with fertilizer grade acid. Unground phosphate rock is fed into the first of a … Read more

Sludge Production Control from Wet Phosphoric Acid Processing

The accumulation, handling, and utilization of sludges formed from wet process phosphoric acid is one of the major problems in the industry. The purpose of this paper is to explain some of the considerations and techniques that can be employed to provide some measure of control over the problem. An acid made from a Central … Read more

Pneumatic Stowing – Backfilling Technique

Pneumatic stowing was first introduced in longwall mining in the middle twenties. Since that time it has advanced through many stages of development, particularly abroad, which have greatly improved its efficiency and contributed to its growing use. Pneumatic stowing originated in coal mining but has also been adopted in metal mining. Pneumatic Conveying of Stowing … Read more

Grinding Circuit Control

There is much interest in the automation of entire comminution circuits. At the present technological level it is possible to automate a circuit but to date it has not been done. To successfully automate a circuity a number of problems must be solved. Not all of them are engineering problems. The purpose of this paper … Read more

Bedded Deposit Mining Methods

The planning of an underground mine for successful extraction of a bedded deposit in sedimentary rocks requires the integrated evaluation of many interdependent problems. The development and coordination of feasible solutions are the responsibility of the mining engineer. One of these problems will be discussed herein; this is the design and layout of mine workings … Read more

Magnetic Mechanical Separator

Over a considerable period of time great interest has been shown in selective dry concentration of fine ferromagnetic particles, although it is only recently that new permanent magnetic materials have been made available to permit building of such permanent magnetic separators. It is well known that the conventional drum separator does not efficiently separate fine … Read more

Lock Hopper Slurry Pump

The pumping of abrasive and sometimes corrosive slurries is normally carried out at modest heads (say 100 ft) with specially designed centrifugal pumps. When heads become higher than this, two or more pumps are used in series but ultimately the system requires staged pumps with consequent increase of costs. The only other type of pump … Read more

Kaolin Mining and Processing

Kaolin is an important industrial mineral because it exhibits desirable properties in many applications and because of its relatively low cost. Approximately 2,000,000 tons of kaolin from Georgia and South Carolina are processed and used commercially in the United States each year. Strictly defined, the name kaolin is applied to a group of hydrous aluminum … Read more

Hydraulic Backfilling a Method of Ground Support

Problems of mine backfilling and fill material deposited underground, the characteristics and relationship between the deposited fill material and overlying ground, and the practical applications and limitations of hydraulic backfilling as ground support are discussed. Ground Pressure and Backfill There are many theories explaining the formation and distribution of stresses around underground excavations. It has … Read more