The following conclusions are drawn from the results of these investigations: The reflux leaching method is an effective means for extracting aluminum from crude Al-Si alloy. Aluminum obtained by this method will contain from 1 to 6 percent silicon, 0.04 to 0.8 percent iron, and 0.01 to 0.9 percent titanium. With only minor changes in … Read more
Zirconium diboride of a quality comparable to that produced commercially from zirconium dioxide may be synthesized directly from zircon. The quantities of residual carbon and silica are not excessively high, but it is believed that some refinements in procedure may lower these percentages. The grain size of the final product has been demonstrated to be … Read more
The investigation of the zirconium-gadolinium equilibrium diagram revealed a eutectic system with limited terminal solubilities and one peritectoid reaction. The eutectic point occurs at about 82 percent gadolinium. The eutectic isotherm, at 1,220° C., extends from about 12 to 99+ percent gadolinium. The peritectoid isotherm, at 890° C., involving the alpha-beta transformation of zirconium, extends … Read more
More than 95 percent of the total tin in Bolivian mine-run ores can be volatilized and recovered as tin chlorides at temperatures ranging from 520° to 565° C. Equally high percentage recoveries of tin can be obtained from low-grade Bolivian concentrates at temperatures of 565° to 600° C. Minus 35-mesh ores and concentrates can be … Read more
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 These, together with several unpublished methods, involve wide differences in technique although they are all similar in principle.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 … Read more
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 … Read more
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 … Read more
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 … Read more
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 … Read more
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 … Read more