Percussion Drilling
The past 15 years have seen rapid advances in the metallurgy of materials for drill machinery and bits, but rock drilling itself continues to be largely an art. Jet piercing, roller bit rotary drilling, and rotary percussion are all promising new techniques, but the percussion rock drill, still used for 90 pct of the blastholes […]
Tube-Furnace Method for Rapid Determination of Sulfur in Coal
Subsequent to the work of A. Vita in 1920, a number of investigators have published data dealing with the rapid determination of sulfur in coal using a high-temperature combustion furnace. These, together with several unpublished methods, involve wide differences in technique although they are all similar in principle. . Materials and Experimental Work A metered […]
Economics of Long Transport Conveyor Belt
In 1955, the Ideal Cement Company decided to increase the production at its Ada, Oklahoma operations. After many studies it was decided to build a complete new plant along side the old, near the site of the original 1907 plant. The new plant was to have a production of three million barrels annually while the […]
Mineral Aggregate Specifications
The largest use of aggregates is for highway construction. Furthermore, the majority of sales for other than highway uses is dependent upon compliance with state highway specifications because it is widely accepted that, if an aggregate is satisfactory for state highway uses, it will be safe for almost any other construction purpose. It, therefore, is […]
Selective Maintenance of Hydraulic Components on Mining Equipment
Commonly accepted maintenance methods are being outdated by the rapid acceptance and use of more complicated hydraulic circuitry on modern mining equipment. It is no longer adequate to use the maintenance program to merely repair or sustain equipment operation. Ever increasing operating costs place a huge premium on lost production time. It has therefore placed […]
Type of Continuous Miner
While coal production over the past 25 or 30 years has been on a horizontal plane, coal’s share of the total energy market has declined. To participate more effectively in this total energy market, it is necessary to produce coal more efficiently. It is the obligation of all management, employees, and mining departments to gear […]
Determining the Tensile Strength of a Rock
The tensile strength of rock is its weakest property, and this property apparently enters into all failure phenomena, whether underground or on the slope of an open pit. Therefore, it is essential that detailed quantitative information is known about the tensile strength of rock if the design engineer is going to select the proper pit […]
Sodium Vanadate under the Salt-Roast Process
A study has been made of the reaction mechanisms occurring during the salt-roast process to form water-soluble sodium vanadate compounds from the vanadium oxide compounds present in vanadium-bearing ores and concentrates. Two reactions have been identified, either of which lead to water-soluble compounds oxidation of sodium chloride by water vapor and oxidation of sodium chloride […]
Grinding Ball Wear & Radioactive Tracer Technique
This paper summarizes the results of an investigation sponsored by The Coates Steel Products Company. The objective was to determine the relative effects of certain chemical and physical properties on the wear resistance of grinding balls when grinding cement. In making this study, a number of types of balls were used in both dry and […]
Solid Liquid Separation by Flocculation
When is use of a flocculant justified in terms of overall process economy? when it results in process improvement, such as producing a clear liquor for electrolysis, precipitation, ion exchange, or solvent extraction; when it results in satisfying requirements of pollution abatement ordinances; when it results In increased recovery of values that would otherwise be […]