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By C. W. Lawr

THE ores mined by the Santa Gertrudis Co. at Pachuca, Mexico, are mainly silver-bearing; they also yield some gold and carry a little copper. Strong cyanide solutions are used to dissolve the silver and gold, and the mechanical loss of cyanide at the tailings filter has been considerable. Prior to the year 1923, the pulp, after agitation, was given a 35 to 37-min. wash with barren solution in a Butters-type leaf filter; the discharged slime cake was repulped and pumped into eight Merrill self-sluicing slime presses in which the slime was given a further wash with barren solution for 25 to 35 min., followed by a 10-min. water wash. At that time the barren solution titrated around 0.350 per cent. free KCN and 0.500 per cent. total KCN. (Aero brand cyanide is used.) It can readily be seen that a 10-min. water wash would leave considerable cyanide in the filter cake, which of course was a total loss. This averaged 0.522 kg. (1.15 lb.) KCN per ton of solution. As the daily discharge to. the dam was 1600 tons1 of slime of a 2: 1 ratio of liquid to solid, the value of this mechanical loss of cyanide was an important item and its recovery held alluring possibilities.

Jan 1, 1929

By Roger M. Turpening

This study was performed to examine the feasibility of using seismic shear waves to detect the presence of abandoned coal mines. !he Antiquity Coal Mine near Antiquity, Ohio was used as a region of known voids. No attempt was made here to accurately locate the mine tunnels if detection was obtained. The results of this study were positive. Sharp changes in the amplitude of the received shear waves were clear indications of the presence of a fluid (gas or liquid) filled region between the source and receivers. When moving the source showed no change in the received signals it was concluded that the voids existed beneath the sensors. Prior to these tests drilling (SM-3) had determined that a void did exist in this area. This void was confirmed by this shear wave test and two additional voids were found.

Jan 1, 2012

Based on the idea to copy crystallisation and precipitation phenomena occurring in nature, a new technology was developed allowing the preparation of metastable, mineral forming solutions. If these solutions are brought into soil or rock formations, directed precipitation of slightly soluble minerals takes place. Immobilisation of dissolved heavy metals as well as overlaying of reactive mineral surfaces with insoluble minerals can be achieved. It is possible to prepare solutions leading to the formation of gypsum, BaSO4, CaCO3, Ca(OH)2, Al(OH)3 or Fe(OH)3. The successful large-scale application of BaSO4 forming solutions was demonstrated in the former uranium mine Koenigstein of Wismut GmbH, (Germany).

Jan 1, 2003

In recent years the use of directional drilling has become increasingly popular in several applications. These include shaft pilot holes, exploration drilling, mine service holes and drilling beneath surface structures and obstacles. The prime objectives are to increase accuracy and reduce time, cost and environmental disturbance.

Jan 1, 1992

By D Gelling

Mineral sands dry plants consist of a large number of repetitive unit operations with significant transport delays, in the form of stream pipes, conveyors and elevators. As part of the P255 mineral sands sponsorship and using the JKMRC developed conductor/non-conductor (CNC) gauges, control loops have been implemented at the multi-duty dry plant of Cable Sands Limited at Bunbury. This paper describes the loops for kV control on a rougher high tension roll machines (HTR). The options available are product grade control and ratio control using the JKMRC CNC gauges, which measure the percent conductors in a stream. The purpose of control is to stabilise the circuit operation against disturbances such as atmospheric and feed disturbances.

Jan 1, 2001

By William P. Blake

Postscript to the paper read by Prof. William P. Blake at the Lake Superior meeting, September, 1904. POSTSCRIPT.*-Since the publication of my paper upon the blackening of the surface of rocks in desert regions, I have noted that similar views of the origin of superficial discoloration in the case of certain rocks from the Salt Lake basin of Utah have been expressed by Prof. George P. Merrill. In the pamphlet, he described the brown-coated weathered boulders from Tooele county, reaching the conclusion that the discoloration was due to the solution of the manganese and iron compounds 'in the interior of the boulder, while they were in the water, and the gradual bringing of this material to the surface through capillarity and its oxidation when exposed.

Mar 1, 1905

The gold deposits of Kalgoorlie are the most important on the Precambrian shield of Australia. Gold was first discovered.'-:.V. ,,.,.-,..Kalgoorlie in June, 1893, and olthough`the original find was of ;:...;;small extent, the prospecting activity which stemmed from it 'led to'the ciscovery.of the lodes of the Golden Mile, some three miles to the south. Th¬ production of thea1algoorlie fiold.a.t December 31st, 1962 was 80,556,572 tons -for -33.,853, 215 ounces of gold. Most of this production has come from the Golden Mile area anu Table 1 summarises the Gplueh Mile. production for periods which correspond approximately to the main phases of operation of the field.

Jan 1, 1964

By E. D. Cockrell, E. P. Hayes

The figures herein presented show that during the year 1938 drilling in the Texas Gulf Coast continued at a slightly lower rate than during 1937. In 1938 there were 21 new oil fields added to the Texas Gulf Coast; also numerous extensions and new sands in old fields. This report for 1938 cannot be compared with the report for 1937 in Volume 127 of the Transactions, because the area covered by this report is less than that covered last year. The cross-hatched area on Fig. 1 shows the limits of this report. Of the new fields, Cordele, in Jackson County, Eureka Heights and Fairbanks, in Harris County, Francitas, in Jackson County, LaRosa, in Refugio County, and League City, in Galveston County, have the greatest promise of prolific production. The 1938 production for the Gulf Coast area was 92,530,467 bbl. as compared to 94,019,355 bbl. for the same area in 1937. This shows a decrease of 1,488,888 bbl. during 1938, regardless of the increase due to the 21 new oil fields. This decrease was caused mainly by the Saturday and Sunday shutdowns (68 days during 1938) and by cut in allowables. The 68 shut-down days amount to approximately 18.6 per cent of the 365 days possible for production. The decrease in the 1938 production amounted to approximately 1.58 per cent. Therefore there was actually a potential increase in the year's production. During the past year, 1637 wells were completed as oil wells, 68 as gas wells and approximately 461 dry holes, as compared to 1672 oil wells, 83 gas wells and 448 dry holes in 1937 on the Texas Gulf Coast. Total wells drilled were 2166 in 1938 and 2203 in 1937. Condensate. sands in old fields and new fields are continuing to increase in importance from the standpoint of retrograde condensation and pressure maintenance. The following fields had major extensions during the year 1938 from the standpoint of increased areas of old sands and new deeper sands:

Jan 1, 1939

By E. D. Cockrell, E. P. Hayes

The figures herein presented show that during the year 1938 drilling in the Texas Gulf Coast continued at a slightly lower rate than during 1937. In 1938 there were 21 new oil fields added to the Texas Gulf Coast; also numerous extensions and new sands in old fields. This report for 1938 cannot be compared with the report for 1937 in Volume 127 of the Transactions, because the area covered by this report is less than that covered last year. The cross-hatched area on Fig. 1 shows the limits of this report. Of the new fields, Cordele, in Jackson County, Eureka Heights and Fairbanks, in Harris County, Francitas, in Jackson County, LaRosa, in Refugio County, and League City, in Galveston County, have the greatest promise of prolific production. The 1938 production for the Gulf Coast area was 92,530,467 bbl. as compared to 94,019,355 bbl. for the same area in 1937. This shows a decrease of 1,488,888 bbl. during 1938, regardless of the increase due to the 21 new oil fields. This decrease was caused mainly by the Saturday and Sunday shutdowns (68 days during 1938) and by cut in allowables. The 68 shut-down days amount to approximately 18.6 per cent of the 365 days possible for production. The decrease in the 1938 production amounted to approximately 1.58 per cent. Therefore there was actually a potential increase in the year's production. During the past year, 1637 wells were completed as oil wells, 68 as gas wells and approximately 461 dry holes, as compared to 1672 oil wells, 83 gas wells and 448 dry holes in 1937 on the Texas Gulf Coast. Total wells drilled were 2166 in 1938 and 2203 in 1937. Condensate. sands in old fields and new fields are continuing to increase in importance from the standpoint of retrograde condensation and pressure maintenance. The following fields had major extensions during the year 1938 from the standpoint of increased areas of old sands and new deeper sands:

Jan 1, 1939

By Michael W. Glasson, Archie M. Richardson, Leo Gilbride, Laine Adair

Andalex Resources, Inc. recently engaged in a ventilation planning exercise that resulted in the construction of a new main fan installation to support longwall coal mining at the Aberdeen Mine. This paper documents the planning process, including underground measurements, modeling, permitting, and construction of the new fan installation.

Jan 1, 1997

Researchers from the National Institute for Occupational Safety and Health's Spokane Research Laboratory installed Split-Set rock bolts instrumented with strain gauges to document the mechanical load response of the bolts in weak ground. Short-term monitoring of the bolts immediately after installation showed that some of the gauges went into tension. It was felt that the force exerted on the bolts to drive them into the hole should have caused the gauges to show compression. The tension probably resulted from the holes having crooked sections. Long-term monitoring over the course of a year also showed that the bolts were bending at some locations and that loads as high as 98 kN (22,000 Ib) were recorded along sections of the bolts. Load cells were placed on the head end of the bolts to determine head loads. Head loads up to 14.7 kN (3,300 Ib) were generated during bolt installation. In addition, closure readings were taken across the drift to determine the convergence rate responsible for bolt loading. A Rock Mass Rating (RMR) was calculated at the site to compare with bolt response. The bolts were installed as part of the rebolting process in an area being repaired because the near-vertical beds in the walls were buckling and causing the wall to fail. The instrumented Split-Set rock bolts will provide data that will lead to greater understanding of the behavior of the rocklbolt support mechanism. It may also be possible to explain the overall performance of the bolts in situ in terms of their design effectiveness. This work showed that load at the head of a Split-Set rock bolt was less than load along the interior of the bolt.

Jan 1, 2005

By R. B. Snow

Inclusions revealed by the ultrasonic inspection of forgings, slabs, and blooms cause costly diversion or rejection of the product. Most of those inclusions are so large that they should have floated out of the liquid steel soon after teeming and been removed when the top discard was taken from the ingot. To investigate the source of the relatively large inclusions found in the body portions of ingots, a large forging ingot was examined from top to bottom along the centerline, and special studies were made of open-hearth and BOP ingots. A study of the inclusion distribution in the as-cast 134-inch-diameter forging ingot revealed only a few inclusions larger than 15 microns in the body of the ingot. Larger inclusions may be formed by entrapment of rising inclusions in large falling dendrites rather than by the precipitation and agglomeration of oxides from the liquid steel-dendrite interface during solidification. The original top crust of the ingot investigated broke away from the hot top and sank to the bottom during the solidification process, as indicated by entrapped inclusions found in a band 12-1/2 inches above the stool. A change in the hot-top insulation practice on subsequent ingots to insure the integrity of the top crust has produced clean ingots. A ZrO2 tracer was added to the hot-topping compound and to the top surface of open-hearth and BOP ingots after teeming. The tracer was found in large inclusions in slabs and blooms from these ingots. Large inclusions in the body of ingots appear to be related to disturbances of the natural freezing and shrinkage processes in the hot- top region of the ingot.

Jan 1, 1972

By F. M. Doyle, P. E. Richardson, E. Peters

A number of studies have attempted to correlate the semiconducting properties of mineral sulfides with their chemical reactivity. Frequently such studies are conducted on polished or abraded electrodes. Defects produced by abrasion may mask the influence of the semiconducting properties of electrodes, e.g., by pinning the Fermi level at the surface or by reducing the lifetimes of photogenerated charge carriers. It is shown that pyrite and galena electrodes have photocurrents that are extremely sensitive to abrasion of the electrodes. On freshly fractured galena surfaces, the space charge layer is readily polarized. Wet-abrasion is shown to produce a relatively thick ptype layer on galena electrodes and this p-type layer has a pronounced effect on the photoresponse. On freshly fractured pyrite surfaces, the Fermi level at the surface is pinned by a surface state. Wet-polishing reduces the magnitude of the photocurrent by over an order of magnitude.

Jan 1, 1993

By J. J. Oberly

WHILE examining lineage boundaries in germanium single crystals as described by Vogel et al.,&apos; patterns of conical etch pits were noted which reveal interesting properties of dislocations. The crystals were grown by pulling in the <100> direction, and (100) surfaces perpendicular to the growth direction were etched 4 min in a mixture of 6 cu cm HF, 10 cu cm HNO3, 6 cu cm acetic acid, 3 drops Br,. Lineage boundaries extended in any direction, but favored the <110> direction. The patterns which were noted first were composed of two or three etch pits arranged symmetrically about the lineage boundary, so that the doublets were spaced equally on either side of the boundary line and the triplets had their center pit on the boundary line. The triplets occurred less often than did the doublets; occasionally combinations were found. Two such combination patterns are shown in Figs. 1 and 2. The orientation of the patterns was determined approximately by subsequently etching the same surfaces in a mixture of 5 cu cm HF, 5 cu cm super-0x01, and 20 cu cm distilled water which produced nearby random square etch pits having edges in the <110> direction. In all cases, the axis of symmetry was <110>, being parallel to the etch-pit edges. Several successive lapping and etching operations showed that the patterns tended to continue through the crystal in the <100> direction, but eventually changed or vanished. It can be seen in both photographs that the pits in the patterns are much further apart than the pits in the adjacent section of the lineage boundary. In Fig. 1, the 10 pits of the pat-

Jan 1, 1955

By Ta M. Li

US mine-related fatalities were reduced by 10.3% at metal and nonmetal operations in 1974, according to a report by the Secretary of the Interior to Congress concerning the administration of Public Law 89-577. While there was no significant change in the overall injury experience, the 157 fatalities were the lowest recorded in the mining industry since federal mine inspections began under the Act in 1970. The report attributes this reduction to the "improvement in the quality and increased size of the inspection force as well as the continuing emphasis on mine safety conditions and practices." The year 1974 represents the first full calendar year in which the Mining Enforcement and Safety Administration (MESA) had responsibility for administration of the Federal Metal and Nonmetallic Mine Safety Act, and the Federal Coal Mine Health and Safety Act of 1969. Prior to MESA&apos;s establishment in 1973, these functions were delegated to the US Bureau of Mines. Research activities in health and safety were continued by the Bureau in 1974.

Jan 12, 1975

This report describes the development of training materials for the operators of underground mining equipment in the underground metal and nonmetal mining industry. The objective was to determine the effectiveness and acceptability of these training materials and to provide the validated training materials to the industry. Ten modules were developed, based on industry need according to accident frequency, accident severity and exposure to the equipment. The final modules were an average of 20 minutes in length and used slides with synchronized narration on cassette tapes. Testing materials are included for use by the mines.

Jan 1, 1984

By D. L. Kelley

High-viscosity water injection has been proposed for use in reservoirs containing high-viscosity crude oils. Previous publications have largely ignored the possible effects of the connate water on the proposed process. This paper describes experimental work which indicates that the connate water will be forced ahead of the injected water to form a bank of low-viscosity water. This decreases the oil recovery which would be expected if such a bank were not formed. These effects are shown for a range of fluid mobilities and connate-water saturations for a five-spot injection system. In general, oil recoveries using viscous water are significantly greater than for untreated water even though they are less than would be expected if no connate water bank were formed. INTRODUCTION The effect of mobility ratio on the oil recovery of wa-terfloods has been known for many years. Muskat first pointed out that the fluid mobilities (k/µ) in the oil and water regions would affect the performance of the water-flood, and he estimated the general effect of these variables.&apos; Since this early work, studies of the effect of mobility ratio on secondary recovery have been reported where mathematical,&apos; potentiometric3 and scaled flow models&apos; were used. These studies have shown that a reduction in the mobility ratio between the oil and the displacing fluid would cause additional oil recovery when water-flooding reservoirs containing viscous crude oils. Studies reported by Pye- nd Sandiford 8 have indicated that chemicals to increase injection water viscosity are now available and can be used to reduce the over-all mobility ratio of a waterflood. Where mobility ratios are controlled by the injection of viscous fluids, the connate water of the reservoir can play an important part in the displacement of the reservoir oil. The purpose of this study was to determine the effect of the connate-water saturation in waterfloods where viscous waters are used for injection. DISPLACEMENT OF THE CONNATE WATER Russell, Morgan and Muskat7 were the first to recognize the mobility of connate waters in waterflooding. They conducted waterfloods on oil-saturated cores containing 20 and 35 per cent irreducible water saturations, and found that from 80 to 90 per cent of the "irreducible" water was produced after only one pore volume of water was injected. However, their experiments were conducted at rates of flow significantly higher than those ordinarily occurring in waterfloods. Also, the cores were only from 4.0 to 8.5 cm long. Brown 4 studied a 100-cm linear sand pack which had been prepared to contain connate water and oil. He used 140- and 1.8-cp oils with injection water of essentially the same viscosity as the connate water. He found that all of the connate water was displaced by the injection water in both cases. However, the injection volumes required for complete displacement of the connate water were considerably higher in the case of the more viscous oil. To verify the results of the foregoing experiment, a 10-ft-long linear model was constructed by packing 250-300 mesh sand in a 1/2-in. diameter nylon tube. The model was evacuated, saturated with a brine of 1-cp viscosity, and flooded with a 41-cp mineral oil to the irreducible water saturation of 10.9 per cent. The model was then waterflooded by the injection of a water solution which had an apparent viscosity of 42.6 cp. The solution consisted of 0.5 per cent methylcellulose in distilled water. The viscosities of the oil and connate water were measured with an Ostwald viscosimeter. The viscosity of the polymer solution was calculated by Darcy&apos;s law using pressures measured during actual flow conditions. The ratio of the mobility in the oil region to the mobility in the inject ion-water region was approximately 0.32. The mobility ratio of the oil region to the connate-water bank was approximately 14. The mobility ratio between the connate-water bank and the injection water region was 0.024. Approximately 84.5 per cent of the recoverable oil was produced before water breakthrough. Immediately following breakthrough, oil and connate water were produced at an increasing water-oil ratio until the viscous injection water broke through. At viscous-water breakthrough, 96 per cent of the original connate water had been produced. After breakthrough of the viscous water, there was no additional production of connate water or oil. The near-

Jan 1, 1967

By R. K. Koch

In seeking substitutes for such critical metals as chromium, cobalt, and nickel, the Bureau of Mines investigated techniques for shape-casting titanium in rammed sand molds. Castings were made in olivine, garnet, chromite, and, for comparison, zircon. It was found that commercial-grade castings up to 31 lb (maximum capacity of furnace) could be made in zircon or olivine molds if a zirconia mold wash was used. Castings up to 4 lb could be made in chromite molds, but heavier castings suffered from some mold-metal reaction. Garnet molds were found to be unsatisfactory for castings of all sizes because of gas blows and rough surfaces. In other tests shell castings of acceptable quality were produced in water-glass-bonded zircon and olivine molds up to weights of 8 lb, but chromite molds were unsatisfactory because rough casting surfaces were caused by mold-metal reaction. Unlike the currently used commercial processes, neither the rammed-sand nor the shell-molding processes developed by the Bureau of Mines generate noxious fumes at any step.

Jan 1, 1980

By J. M. Mutmansky

This paper outlines the results of a study of the opinions of practicing engineers concerning the value of environmental engineering courses in a mining engineering curriculum. One hundred engineers with significant experience in mining-related engineering work were carefully chosen. Of the 67 responses, about half were from mining engineers, and the other half were from environmental engineers. In this paper, the results of the survey are outlined. The number and type of courses recommended by the respondents are summarized as well as the specific topics recommended for inclusion in a mining engineering curriculum. The survey form also asked for the stages in the mine life when environmental experts were needed and the percentage of environmental engineering performed by outside experts for many mining-related environmental tasks. The results of this line of questions are provided. Finally, the paper offers a comparison of the results for environmental engineers and mining engineers and analyzes the differences.

Jan 1, 2003

By R. B. MacGillivray

The No. 2 Seam at Van Dyks Drift Colliery was found to be made up of six easily recognizable bands or plies of differing qualities. Not only did the plies differ from one another in quality, but their thickness and quality varied laterally across the mine. The economic production of a Iow-ash blendcoking coal for supply to the Japanese Steel Mills called for the mining of different portions of the seam. The portions that could be extracted economically varied in thickness and position within the No. 2 Seam across the mine. A unique system of selective mining had to be developed involving the dispatch of two separate streams of coal out of the mine. Conventional American mechanized pillarand-stall mining was used, and the productivity was improved by the installation of twin conveyor belts into a double-header section. The method of grade control that was instituted to ensure efficient extraction of the available coal reserves is described.

Jan 1, 1985