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By Nicholas J. Grant, Ernest P. Abrahamson

IN recent work, Bloom and Grant' and Stein and IGrant' have indicated that a high temperature chromium phase exists. In the 68 pct Cr-Ni binary they found a eutectoid reaction, P chromium transforming to a chromium plus y nickel at 1215°C. Un-

Jan 1, 1957

Jan 1, 1957

By C. H. Herty Jr, C. H.

FEW subjects have attracted the attention of metallurgists more than oxygen in steel. From the days of Mushet and Ledebui interest in this subject has been increasing, and as additional knowledge has become available, the problem has naturally grown more complex. Instead of using the simple term "oxygen" we now distinguish between iron oxide, silicates of various kinds, oxysulfides, oxygen as gas and oxygen in solid solution in steel. There are five general methods for determining oxides in steel: hydrogen reduction; vacuum fusion; various wet-extraction methods, including electrolytic methods; methods depending on volatilization of the iron away from the oxides; and metallographic methods. For oxygen in solid steel each of these methods has both advantages and disadvantages. The hydrogen-reduction method is of no use on steels above about 0.20 per cent. carbon; 1 furthermore, it gives only FeO and possibly some MnO. The vacuum-fusion method2 is expensive and gives total oxygen, with the exception of some A1203, and does not differentiate between the various oxides in which the oxygen exists. Most of the wet-extraction methods3 give only the more insoluble oxides SiO2 and A1203, though the iodine method gives MnO to an uncertain degree (information that may be more misleading then no information

Jan 1, 1957

R. W. Guard (General Electric Co., Schenectady)— The method of fractional replication discussed by the author has proven very valuable to us in applied research connected with alloy and process development where many of the same experimental difficulties exist. Several of our experiences may be of assistance to those who want to apply the method in these fields. Contrary to the author's observation that interactions are rarely significant, we have found in a number of cases that first order interactions exist which are significant and metallurgically important. Because of this difference there are two further precautions which should be taken in order to minimize the difficulties from this point. First, in evaluating the importance of

Jan 1, 1957

Jan 1, 1957

By G. E. Frantti

UNDER the auspices of the Geophysical Committee of Michigan College of Mining and Technology, an investigation was made in Michigan's Upper Peninsula to obtain geophysical data" related to the regional subsurface geology in the area covered by Paleozoic sediments. The area surveyed includes that portion of the Upper Peninsula which lies between R18W to R26W and T41N and T49N, covering approximately 1300 square miles. On the index map, Fig. 1, it is represented by the cross-hatched zone west of Munising. Four of the five sites of detailed investigation are indicated by the letters A, B, C, and D. A detailed gravity and magnetic survey had previously been conducted by J. G. Wilsonz near Perkins, 8 miles north of Rapid River, on a local anomalous area. Results of his work, which showed a large positive magnetic anomaly associated with a gravity anomaly, aroused interest in the possible economic significance of the formations underlying the Paleozoic sediments in this part of the Upper Peninsula. Early in the 1900's the Michigan Geological Survey, as well as many private companies, had done a considerable amount of dip needle work near the southwest corner of the area discussed in this paper. Most of the information available to the writer was obtained from indicated magnetic anomalies on the geological map of the northern peninsula of Michigan. Results of the geophysical activities of mining companies in the vicinity of the Marquette range and Gwinn district were unavailable to the author. Physiography and Geography: The region under consideration has low to moderate relief. About half the area is comprised of swampy lowlands, and because of the swamps and forests much of the land is almost inaccessible. The major drainage system is dendritic, with streams flowing into Lake Michigan on the south and Lake Superior on the north. The general geology, shown in Fig. 2, indicates an overlay of Paleozoic sediments on pre-Cambrian formations along a line running approximately south from Marquette (not shown on the geological map). Actual contact between pre-Cambrian and Paleozoic sediments is not known because most of the area is covered with glacial till, and outcrops are very scarce. Exposures of the Paleozoic sediments show that these beds in the northern areas dip gently under Lake Superior and that in the southern areas they 'dip gently to the southeast. Outcroppings of the pre-Cambrian formations occur primarily to the west of the surveyed area except in the northwest corner where the Laurentian series outcrop as far east as the Gwinn district and also in T46N, R24W. Instrumentation: Gravity measurements were made with the Worden portable gravity meter. Since this was chiefly a reconnaissance regional survey, both the large and small dials were used. The instrument used had a constant of 0.0035 milligals per scale division, a working range of about 25 milligals.

Jan 1, 1957

By R. C. Weed

LEACHING in place at Cananea began in the 1920's on a limited scale. The first plants were small wooden boxes located underground in the Capote and Oversight mines, and output was low. Scrap iron was used as precipitant. Later several other small plants were started up. Leaching was limited entirely to underground areas, and production remained low. The Veta precipitating plant, the first on a larger scale, was put into operation in the late 1920's. After a period of intermittent service it was rebuilt in 1946 and has since been running continuously. In 1943 work on the Colorada open pit was started. This produced 40 million tons of waste, which averaged 0.20 pct capper. When these dumps had aged a few years it was decided to leach them on a large scale, and after considerable research and investigation a leaching system of pumps and pipelines was laid out and installed. At the same time the Ron-quillo precipitation plant was built to treat the copper solutions from the pit dumps. This plant started operation in March 1953. Leaching areas consist of the Colorada pit dumps and various mined out and caved underground stopes. The principal mineral, chalcocite, leaches readily in a weak sulfuric acid solution containing ferric iron. Enough pyrite is contained in the areas to produce an acid-ferric iron solution strong enough to dissolve the copper. Each area is studied to determine the best method of distributing the water over it and the best method of collecting the copper-bearing solutions after leaching has taken place. Water is generally distributed by means of ponds, ditches, and sprays. Spraying has proved the best method of spreading the water evenly; however, in a dry climate some water is lost through evaporation. After passing through the leachable material the solution is collected underground by dams and bulkheads and on surface by dams. An effort is made to give the maximum storage capacity practicable.

Jan 1, 1957

By Fitterer, G. R.

The impact of the work of Herty "et al" on modern liquid steel technology can only be evaluated by first setting the stage as it existed in 1926. It is important to briefly review not only the steel making process and viewpoints regarding methods of refining, but also to describe the tools which were available for research at the time. One must recall that only 15 years before the beginning of this program, the open hearth production exceeded that of the Bessemer in the United States. Many open hearths were still operating on producer gas (a very inefficient fuel), although some plants were converting to the use of natural gas and very few to oil. Continuous rolling of wide strip started this year. The Faraday Society in England held a World Conference on Physical Chemistry in Steel Making in 1925 and the contributions to this work created considerable interest throughout the world and it appeared that physical chemistry might convert the art of steel making into a science. These papers, however, attempted to solve the problems through the use of the older physical chemical concepts such as Nernst's numbers, etc. and considerable data were missing. In 1923, Lewis and Randall had published their book Thermodynanzicsl and this was later to establish and standardize the steps which are now accepted for the calculation of physico-chemical equations. At the time this research work was started, there were no small high frequency induction furnaces. Northrup had just invented his high frequency furnace and a few large units had been instilled in plants. The vacuum fusion method lor the determination of oxygen in steel was

Jan 1, 1957

By John A. Emery, Frank G. Snyder

Mining geology has a threefold objective: to guide prospecting for new ore, to evaluate known orebodies as development risks, and to supply the detailed knowledge of ore structures necessary for more economical extraction. The role of geology in exploration is well established. This article will deal solely with orebody evaluation and the application of geology to development and mining problems as practiced by St. Joseph Lead Co. in the southeast Missouri district, which for many years has supplied approximately 30 pct of U. S. lead production. The primary concern of the present discussion is geology in the district, not geology of the district. The southeast Missouri district, locally called the Lead Belt, includes parts of St. Francois, Madison, and Washington counties. The first recorded mining was about 1720 at Mine La Motte in Madison County on surface showings of lead ore. Later discoveries near Bonne Terre, twenty-five miles to the north, led to extensive prospecting and underground mining. To date the district has yielded well over 8 million tons of pig lead, valued at more than $1 billion. By far the greater part of the lead production has come from an area of 50 sq miles, centering Fig. 1-Central portion of southeast Missouri on the city of Flat River, as shown in Fig. 1.

Dec 1, 1956

By Bernard Rachlin

In the mineral industry measurement of density or specific gravity of slurries is often necessary or highly desirable. To date the most successful method of measuring the specific gravity of various media is to hand weigh a constant volume sample of the slurry. This method is time-consuming, however, and is intermittent rather than continuous. Most density measuring instruments in use today are variations of three basic systems: air bubble tube systems, radioactive methods, and displacer systems. The high cost of the radioactive cell, combined with the precision electronic measuring that is required, limits the practical utility of this procedure to a small percentage of critical processes. In the air bubble systems clogging of the bubble tubes with solids has rendered this type of measurement completely ineffectual for many applications. Continuous or intermittent purging of the bubble tubes with air or water to prevent tube clogging has been tried but has not been very successful, especially in the heavy media process.

Dec 1, 1956

By Laurence W. Casteel

Indian Creek Mine, newest of the St. Joseph Lead Co. properties, is located in southeast Missouri on the flanks of a buried porphyry ridge. Here the orebodies are very irregular in size and shape and have a regional pitch of about 15°, which may vary locally from 0 to 90°. To maintain an economical grade of ore, selective mining is imperative. The room and casual pillar method is employed with 20-ft diam pillars 35 ft apart where possible. Stopes vary in height from 10 to 55 ft. All are too small to supply a loading unit continuously.

Dec 1, 1956

By W. H. Wamsley

Used in combination with conveyor belt haulage, bucket wheel excavators offer unusual possibilities for low excavation and haulage costs. Originating in Germany, these machines are now in use or on order for Australia, Northern Rhodesia, the Belgian Congo, Italy, Yugoslavia, France, Belgium, Indonesia, and the Union of South Africa. A diamond mine in South Africa that has been using German bucket wheel excavators since 1928 purchased American cable-way excavators and American scraping equipment after the war. Operating cost for this equipment was double that for the bucket wheel machines operating in the same mines with crawler-mounted stackers. Machines built and operated in the U. S. are, as far as the writer knows, confined to the northern Illinois coal field, where they are used in conjunction with large shovels to strip overburden too high to be reached by the 30 to 40-yd shovels. Their long stacker belts can deposit the spoil far enough behind the coal face to avoid slides, in such a manner as to make reclaiming the land easier. These large, specialized machines are now being made by Bucyrus-Erie Co. but are not adaptable to many open pit mining situations.

Dec 1, 1956

By J. P. Zannaras

If we assume that testing of the model started at time C, that time t2 was the instant at which the elastic limit of the material was passed at the points of the maximum stress, and that at time t3 the failure of the model was completed as shown in the typical photograph (Fig. 1), then actually the photograph shows the final results of what took place between time t2 and t3. By the principle of similitude all conclusions drawn from the behavior of the model were applicable and valid for actual mine roofs up to the time t, after time t, motions and friction came into play during the destruction of the model. The events between t2 and t3 and the photograph itself are not representative of the events expected in an actual mine roof unless corrections imposed by the principle of similitude are made.

Dec 1, 1956

By J. R. Dawson, J. A. Glunt

Vesta No. 4 and 5 mines supply most of the high volatile coal required for Jones & Laughlin's by-product coke plants. Until 1944 all coal produced in these mines was loaded by hand. Pressure to mechanize at Vesta was brought on by the manpower shortage in World War II, and in 1943 a decision was made to change to mechanical loading. It was the opinion of those concerned that by use of selective mining the coal would be clean enough to be processed by the existing preparation plants. At that time coal cleaning at Jones & Laughlin consisted of hand picking the larger sizes at the mine tipples and wet washing at plants located at the Pittsburgh and Aliquippa Works. A typical section of the Pittsburgh seam as it occurs at Vesta is shown in Fig. 1. The 14 to 16 in. of drawslate immediately over the coal is too soft to be used for roof and must be taken down, leaving the rooster coal just above for roof. In selective mining an attempt is made to mine the coal under the drawslate first and then load out the drawslate separately as refuse. In full seam mining slate and coal are shot down at the same time and loaded out.

Dec 1, 1956

By Eldred D. Wilson

Apropos of metals low in the series illustrated by Dr. Butler's Table II, it is interesting to note that Cress and Feldman reported traces of platinum metals in several samples of alunite. They found, chemically and spectrographically, several traces of platinum, palladium, and rhodium in alunite from Sugar Loaf Peak, near Quartzite, Ariz.; silver, platinum, and rhodium in alunite from Rio Grande County, Colorado; and traces of rubidium and gallium in various samples of alunite. These authors stated that the platinum metals appear to be present as oxides and suggested deposition by hydrothermal solutions under near-surface conditions.

Dec 1, 1956

By R. R. Hartman, W. B. Agocs

In the course of a return flight from Olympia, Wash., to Laramie, Wyo., an airborne magnetometer profile was recorded continuously. The level of flight was controlled at barometric levels along segments of the flight. Barometric altitude was changed from 3000 ft to a maximum of 12,000 ft above mean sea level to take care of topographic variations. Terrain clearance varied from 800 to 7300 ft. Horizontal positions were obtained by recording and tying to cities, towns, airports, river crossings, and other landmarks in the course of the flight. Figs. 1-6 show the course of the flight and the general geologic and tectonic features traversed. The flight line begins south of Olympia, Wash., and proceeds south across the Puget-Willemette depression to the Columbia River. Thence it proceeds eastward along the Washington-Oregon border across the Cascade Mts. and lava flows and the Umatilla basin to Pendleton, Ore. From Pendleton it traverses the Blue Mts. uplift of Oregon in a southeasterly direction, and then to the Boise basin of southwestern Idaho. The flight line swings in an easterly direction as it passes over the Snake River downwarp to the south of the Idaho batholith. It then passes over the northern portion of the Great Basin and the heavily overthrust area at the intersection of the Utah, Idaho, and Wyoming borders. The flight then assumes an easterly course to cross the series of basins and uplifts of southern Wyoming and terminates near the western flank of the Laramie uplift.

Dec 1, 1956

By R. I. Williams

Kennecott Copper's mining activities in Arizona are conducted by the Ray Mines Div., located in Ray, Ariz., in the Mineral Creek mining district about 60 miles southeast of Phoenix. The Ray orebody lies in a mineralized zone belted on the east, west, and north by well defined faults. The orebody consists principally of schist with intrusions of quartz porphyry and diabase. The dominant ore mineral in the schist and quartz porphyry is chalcocite, with some native copper, and in most areas the orebody has been heavily oxidized. In the diabase the dominant ore mineral is chalcopyrite. Ore deposition in the schist portion is very erratic, with no apparent structural explanation. In 1873 silver prospectors opened the mining district, but it was not until 1899 that an English company made the first major attempt to exploit the copper deposits. This venture failed because of improper sampling and limited development work. In 1904 D. C. Jackling, Seeley Mudd, and Philip Weiseman became interested in the Ray Copper Co. and the Gila Copper Co., which later merged as Ray Consolidated Copper Co. In 1926 the Nevada Consolidated Copper Co. took over Ray Consolidated and in turn was taken over by Kennecott Copper Corp. in 1933. The extensive program of surface and underground development and exploration begun in 1907 continued through successive changes of management and ownership to the present time.

Dec 1, 1956

By H. Herbert Hughes

In the years following World War II, L. de Roll S.A., Zurich, Switzerland, perfected its vertical kiln. De Roll first became interested in cement-manufacturing equipment in 1947, not only kilns but also the crushing, grinding, and handling equipment required for a complete cement plant. The parent company, Louis de Roll Iron Works, S.A., Gerlafingen, Switzerland, was founded in 1804. In its six plants, and with its associated companies, de Roll manufactures and installs equipment for a wide variety of industries-chemical and metallurgical operations, fats and oils plants, and municipal refuse incinerators and sewage disposal installations. Vertical shaft kilns, of course, are as old as Portland cement itself. Their fuel economy has long been recognized, particularly in Europe where fuel costs are high. But the disadvantages of old-type shaft kilns have been the lack of consistent quality of the clinker, the small capacity, and the relatively high labor costs.

Dec 1, 1956

By Robert F. Love

Deep under the hills of southwestern Wyoming lies a nonmetallic mineral deposit of incredible dimensions and value. This nearly pure, horizontal bed of the mineral trona, a sodium sesquicarbonate (Na2HC0,.NaHC08.H20), is found in the Green River formation some 1500 ft below surface. It is believed that evaporation of an ancient saline lake left this sodium carbonate as the evaporite and mysteriously left practically no sodium chloride, which is the common constituent of an evaporated saline lake. The trona bed averages 10 ft in thickness and extends over an area of several hundred square miles. In 1938 a geologist with the U. S. Geological Survey identified the trona in the core from a former oil exploration drillhole. By so doing, he initiated the developments of a chemical industry of impressive growth in the area, an industry on the threshold of further and much more spectacular growth. A drilling program by the Union Pacific Rd. and Intermountain Chemical Co. in the early 1940's succeeded in blocking out mineable reserves of several hundred million tons. Development of the deposit started in 1946 with the sinking of a 12-ft diam, concrete-lined shaft 1500 ft deep-followed by construction of a small pilot calcining plant. Actual mining of the trona started in 1947 and continued on a limited scale until 1953, when the $15 million surface facilities were completed, along with the second shaft and other expanded underground facilities. Since April 1953 the mine has been producing more than half a million tons per year, from which the refining plant has produced more than 300,000 tons per year of high quality soda ash.

Dec 1, 1956

By T. M. Berry

In the past few years changes have taken place in shaft sinking. Progress has been made with types of machinery designed, developed, and made available to shaft sinking contractors. This is particularly true of drilling and mucking equipment. Compared with conventional clamshell loading, mucking or loading with a crawler-mounted overshot loader is a new technique for shaft work. There are several methods of clamshell loading. Dravo Construction Co. mounts an air tugger on the clamshell to operate the closing line. The load, or holding line, is attached to the hoist of a crane or whirler at the shaft collar. The clamshell is raised or lowered by the hoist when a signal is given by a bell or light system operated by men at the bottom of the shaft. Two men control the drift of the clamshell with tag lines, pulling it to any position in the shaft for loading, or over the shaft muck bucket for emptying. One man operates the air tugger to open and close the clamshell by means of two lines attached to the operating air valve, just as reins are used to drive a horse. One man operates the signal telling the hoist operator when to raise or lower the clamshell. This method requires two hoisting lines in the shaft-the line from the mine hoist that lifts

Dec 1, 1956