A Mineral Dressing and Economic Study of a Complex Arsenical Ore

The factors that influence the choice of a method for treat­ment of an ore comprise the technical and economic limitations and advantages, derived in detail and balanced according to the exigencies of the particular situation.

Separation of Cadmium from Zinc in the Purification Step of the Leaching Cycle

The purpose of this investigation is to determine the effect of the factors listed previously by conducting a series of tests that will indicate the ex­tent to which the purification is influenced by time, temperature, zinc oust size, zinc dust quantity, iron concentration, two stage precipitation, and aeration.

Montana Talc; Problems in Physical Properties

General information on talc, including foreign and United States occurrences, origin, and uses is covered. Montana deposits are discussed in greater detail as to location, geology, mineralogy, and mining. Studies of talc by petrographic and x-ray methods and an experiment to determine the porosity are described and discussed.

Mineralization of the Bonanza Mine

The Bonanza mine of the Emery mining district in Powell County is on the largest veins in the area, and is developed to a depth of 680 feet by an incline shaft following the dip of the structure. Sulfide ores carrying gold and silver values are mined throughout the area which is easily accessible by road from Deerlodge, Montana, ten miles west of the district.

The Lilly Mine of Powell County, Montana

For many years the Elliston District, of Powell County has been a minor producer of gold, lead, zinc, and silver. Although never among the largest producing districts of the state, it has with the exception of the war years supplied a notable tonnage of ore to the neighboring mills ever since the first placer and lode claims were located there during the late eighteen hundreds.

An Isothermal Study of an S.A.E. 6150 Steel

The purpose of this thesis is to set forth the method followed, the laboratory procedure practiced, the results obtained, the conclu­sions drawn, and the recommendations proposed as a consequence of a metallographic study of the isothermal transformation of an S.A.E. 6150 steel.

The Alloys of Gallium and Indium

Thermal analysis VIPS used to construct cooling and heating curves from which the phase diagram was determined. The data for the entire set of cooling curves were obtained by the use of mercury thermo­meters.

Hot-Dip Aluminizing of Low-Carbon Steels

In a relatively short period of sixty-five years, aluminum has grown to the rank of fifth in total weight of met­als produced in the world. Throughout its short life, aluminum has been found to have excellent corrosion-resistant properties; yet only in recent years has aluminum been under consideration as a corrosion-resistant coating for iron and steel.

Physiographic Surfaces and Weathering Near Butte

Three cycles of erosion have modified the Boulder batholith. The earliest cycle produced a peneplaination that has been largely obliterated by a partially completed intermediate cycle, and the recent cycle now in progress.

A Mineral Dressing Study of the Benefication of Philipsburg Manganese Carbonate Ore

The beneficiation of rhodochrosite ore to the extent that it is suitable for nodulizing and subsequent use in the steel industry is intriguing. Such ores from certain mines is relatively easy to beneficiate, but the rhodo-chrosite ore from several deposits of the Philipsburg district has never been successfully up-graded by any of the several known beneficiating methods.

The Isothermal Transformation Curve for S.A.E. 6150

More than 3000 years ago, men began quenching and tem­pering tools to improve their physical properties. The an­cient people found that iron was easier to shape and form in a heated condition. Charcoal was used as the fuel, and when the shaping process was completed, the smiths cooled the piece in the most obvious way, quenching in water. Quite un­intentionally, these people stumbled on the process for im­proving the properties of iron, and the art of blacksmithing began.

Debris flow magnitudes: a global catalog

The episodic occurrence of debris flow events in response to stochastic precipitation and wildfire events makes hazard prediction challenging. Previous work has shown that frequency-magnitude distributions of non-fire-related debris flows follow a power law, but less is known about the distribution of post-fire debris flows. As a first step in parameterizing hazard models, we use frequency-magnitude distributions and cumulative distribution functions to compare volumes of post-fire debris flows to non-fire-related debris flows. Due to the large number of events required to parameterize frequency-magnitude distributions, and the relatively small number of post-fire event magnitudes recorded in the literature, we collected data on 73 recent post-fire events in the field. The resulting catalog of 988 debris flow events is presented as an appendix to this article. We found that the empirical cumulative distribution function of post-fire debris flow volumes is composed of smaller events than that of non-fire-related debris flows. In addition, the slope of the frequency-magnitude distribution of post-fire debris flows is steeper than that of non-fire-related debris flows, evidence that differences in the post-fire environment tend to produce a higher proportion of small events. We propose two possible explanations: 1) post-fire events occur on shorter return intervals than debris flows in similar basins that do not experience fire, causing their distribution to shift toward smaller events due to limitations in sediment supply, or 2) fire causes changes in resisting and driving forces on a package of sediment, such that a smaller perturbation of the system is required in order for a debris flow to occur, resulting in smaller event volumes.

Ground maritime structure interaction. Recent failures in inner gravity constructions on the Spanish Coastline

A maritime construction is usually a slender line in the ocean.It is usual to see just its narrow surface strip and not analyse the large amount of submerged material the latter is supporting.Without doubt,it is the ground to which a notable load is transmitted in an environment subjected to periodic,alternating stresses,dynamic forces which the sea's media constitute. Both an outer and inner maritime construction works in a complex fashion.A granular solid(breakwater)breathes with the incident wave flow,dissipating part of the wave energy between its gaps.The backflow tries to extract the different items from the solid block,setting a balance between effective and neutral tensions that follow Terzaghui's principle. On some occasions,fluidification of the armour layer has caused the breakwater to collapse(Sines,Portugal,February 1978).On others,siphoning or liquefaction of sand supporting monoliths(vertical breakwaters)lead them to destruction or collapse(New Barcelona Harbour Mouth,Spain,November 2001). This is why the ground-force-structure interaction is a complicated analysis with joint design tools still in an incipient state. The purpose of this article is to describe two singular failures in inner maritime constructions in Spain deriving from ground problems(Malaga,July 2004and Barcelona,January 2007).They occurred recently and the causes are the subject of reflection and analysis.

Water seepage beneath dams on soluble evaporite deposits: a laboratory and field study (Caspe Dam, Spain)

The paper presents analytical methods and results for assessing the variation in the concentration of sulphate (and other ions) over space and time in groundwater flowing through a soluble evaporite terrain beneath a dam. The influence of effective porosity, groundwater flow velocity and the specific rate of dissolution (K′) are considered. The theoretical analysis was tested in a scale model simulating a dam constructed on heavily karstified bedrock. A simple and useful method for assessing how much material is lost through dissolution and how the rate of dissolution changes over time is considered in the context of the Caspe Dam, Spain.