Search Documents

By C J. Hogan

Increasing demand for fine grinding to improve mineral liberation and metal recovery and the need for stricter control of the environmental impact of tailings deposition poses problems for tailings disposal. This has led to an increasing number of investigations of properties of tailings and their disposal. This paper describes laboratory model testing undertaken on Macraes mine flotation tailings to provide information on tailings behaviour under conditions of subaerial deposition. The in-place density or 'dry density' of the impounded tailings and the impoundment depth relationship are important for utilisation of the available impoundment storage facility and results of dry density to depth relationships are given for the Macraes mine tailings impoundment.

Jan 1, 1993

By William E. Sopper

Heat-dried municipal sludge was applied to a barren burned anthracite refuse bank in 1974. Sludge was applied at rates of 0, 40, 75, and 150 dry metric tons per hectare" Ten species of trees were planted and five species of grasses and legumes were seeded for evaluation. One plot was also irrigated with sewage effluent. The 150 t/ha sludge application rate produced the best overall herbaceous vegetation growth response. The 40 and 75 t/ha sludge application rates produced the best tree seedling growth response. Foliar analyses for trace metals indicated no phytotoxity problems. Analyses of leachate water at the three-foot soil depth indicated that the sludge applications did not impair water quality. Results of the study indicate that treated municipal sludge can be used to revegetate land disturbed by mining activities without adverse effects on the vegetation or water quality.

Jan 1, 1978

This appendix is composed of five sections, each of which is tabbed for ease of access. The sections are as follows: ? Fire incident report forms for underground mine fires. There is one form for each incident listed in Table II-1a. They are ordered chronologically with incident numbers corresponding to those in Table II-la. ? Fire incident report forms for surface mine fires. There is one form for each incident listed in Table II-lb. They are ordered chronologically with incident numbers corresponding to those in Table II-lb. ? Journal article report forms. There is one form for each article reviewed. They provide supplemental information to that contained in the fire incident report forms for selected fires. Index 11-14 keys the journal article report forms to the appropriate fire incident report forms. ? Non-reportable incident descriptions for underground mine fires. This is a listing of underground fires for which MSHA regulations do not require formal reports. ? Non-reportable incident descriptions for surface mines. This is a listing of surface fires for which MSHA regulations do not require formal reports. This appendix is intended to be used in conjunction with the tables and indexes contained in Volume II of this report and, as such, should be considered an integral part of Volume II. The indexes in the body of Volume II provide a means of ready reference to the underground and surface mine incident report forms. For those readers with interests other than those indexed, Tables II-la and II-1b can be used to locate specific incidents of interest. Complete incident information can then be obtained from the corresponding report forms in the first two sections of this appendix.

Jan 1, 1980

As this is the first occasion I have had, and probably will be the only opportunity I shall have, of addressing such a large gathering of members and of student members of the Institute, I desire to- express my very deep appreciation of the honour 'you have paid me in electing me to the office of President for the current year. I realise also that such selection is a tribute to the Company which controls operations here, the centre selected for the annual meeting, but nevertheless there is afforded to the recipient a great deal of pride and of pleasure to hold the highest office in what is, in my opinion, undoubtedly the most important engineering society in Australasia.The past year has witnessed an unprecedented and unparalleled event in the history of the British Empire, and I think that we must all feel a wonderful sense of proud patriotism; the whole world was forced to admire the public calm and the dignity which accompanied the change in our Sovereign Ruler, and great tribute is due to the statesmanship of the Prime Minister, Mr. Baldwin. At this time, we should, I think, place on record our prayer, in common with all his people, that His Majesty, King George the Sixth, may enjoy a long and prosperous reign.The meeting at Port Pirie recalls one who did so much for the advancement of mining and metallurgy, especially in Australia. I refer to the late Mr. Delprat, who, as General Manager of The Broken Hill Proprietary Company Limited, had under his control for many years the smeltery in this centre. As you are aware, he had been elected an honorary member of this Institute, as well as of our sister Institutes in England and in America...

Jan 1, 1937

By Dan Witkowsky

For the 36th consecutive summer, the Colorado Mining Association Education Foundation and the Colorado School of Mines have sponsored “A Total Concept of the Mining Industry” for kindergarten through grade 12 teachers. Teachers from 34 states, plus the District of Columbia and two foreign countries, have graduated from the four-week course. They received six hours of recertification credit. This summer 31 teachers from Colorado, Kentucky, Virginia and Alaska completed the program. The course is unique from other shorter courses in that it solicits teachers of all disciplines from all K-12classes. In addition to the expected earth science and mathematics teachers, the Class of 2004 consisted of educators who teach music, chemistry, biology, social studies, history, basic English and world history. Others in the program included those who teach American history, physical and life science, remedial reading, consumer/family studies, “world of work,” language arts, engineering technology, environmental science, world geography, human anatomy and physiology, and business.

Jan 1, 2004

By John F. Elliott

Because of the importance of the steel industry in the economy, a program of study was undertaken to develop a computer model by which it would be possible to predict the need of the industry for raw materials and energy in the next several decades. This report gives the results obtained it a preliminary 6-month program.

Jan 1, 1973

By Gregory Abramov

Borehole Mining (BHM), a remotely-operated waterjet mining method (Figure 1), has recently achieved two major milestones. It was, for the first time, applied to the extraction of manganese ore and at temperatures below freezing. The 1St stage is a demonstration test that is now underway just north of Emily, Minnesota, where the manganese ore is located 100-160m below the surface and its reserves are estimated to be in excess of 500,000 tons. The deposit was discovered over 60 years ago but, due to the fragile and sensitive nature of this Land of 10,000 Lakes (nickname for the State of Minnesota) and strong environmental restrictions, the iron/manganese reserves were deemed unrecoverable and remained untouched until late 2010 when permission for a single-hole demo-test was issued by the local Department of Natural Resources.

Jan 1, 2011

By Sanjeeva Latchireddi

"Deteriorating ore grade and high demand of metals has tremendously influenced the unit capacity of SAG mills. Pebble circuits have been added to the existing SAG circuits to increase their unit capacity. To make the pebble circuits justifiable, the grate openings are increased almost to 4.5 inches to draw large quantity of pebbles. The inherent transportation problems associated with SAG mills in closed circuit with pebble fraction are more complicated than the single stage SAG mill operation, because the coarse pebbles behave significantly different to that of slurry in pulp lifters. In addition, operation of mills at higher speed, to take advantage of precise design of high release angled shell lifters significantly reduces the discharge efficiency of the conventional pulp dischargers. The presence of a sizable quantity of pebbles in the pulp lifter limits the space available and reduces the flow gradient through the grate thus increases the load inside the mill and hence the mill power-draw. This paper analyses all the problems associated in discharge of slurry and pebbles in SAG mills with pebble circuits. The Outokumpu patented Turbo Pulp Lifter (TPLTM) aims at eliminating the inherent material transport problems to ensure good grinding conditions. Recent installation of TPLTM in a 26-ft SAG mill has proven these claims by reducing the specific power consumption while increasing the mill capacity.INTRODUCTIONThe conventional wisdom is to look at the semi-autogenous grinding (SAG) mill as just another grinding mill in which ball charge, mill filling, and mill speed are varied to attain maximum throughput. Liner design for the SAG was also approached more from a wear perspective rather than a metallurgical and hydraulic-flow perspective. The extensive research work carried out by Latchireddi and Morrell (1997,2003a and 2003b) has demonstrated to think of the SAG as more of a pump in which the grates and pulp discharger end (“impeller”) were designed to efficiently discharge the product sized particles smaller than the grate size with minimal recirculation out of the mill.The rock load in the mill is essentially depends on ore characteristics and the discharge rate of broken particles. The discharge rate of the product material depends on how efficiently the discharge pump (grate and pulp lifters) is operating. Similar to the impeller design affecting the pump capacity, the pulp lifter design affects the discharge capacity (or mill throughput) of the SAG/AG grinding mills. The general arrangement of AG/SAG mills discharge system is shown in Figure 1."

Jan 1, 2007

By Thomas M. Barczak

The resultant load vector is the representation of the forces applied to a longwall roof support element by caving strata into a single, quantifiable measure of support resistance. The relatively complex kinematics of the shield support prohibit a determination of support resistance simply by summation of leg forces. A method is being investigated by the Bureau of Nines to determine the resultant load vector by instrumenting supports with pressure transducers and strain gages to measure leg, canopy capsule, and lemnisoate link forces. This concept has been laboratory tested in the Bureau's Nine Roof Simulator. Functional relationships among variables have been assessed, and confidence intervals have been established for prediction of the resultant load vector parameters.

Jan 1, 1984

A pilot steel ladle injection facility designed to assist in the production of high quality steels suitable for use in pipelines has been built and commissioned at the Basic Oxygen Steelmaking (BOS) plant at Port Kembla Works.The plant design and the injection procedure are described.The performance of the unit and some metallurgical results are discussed in terms of the addition to the steel ladle of various quantities of calcium silicide and a lime based material. The effects of these additions on sulphur content and inclusion morphology and hence on steel ductility are also presented. The influence of ladle lining on desulphurisation is illustrated.On the basis of the experience gathered in the pilot plant a permanent and more sophisticated injection facility has been designed.

Jan 1, 1983

At the present time this plant is treating by direct cyanidation 1,000 tons of ore from Open Cut mining and dumps, and 1,200 tons of current flotation tailing obtained from the Sulphide Mill, per day.The following table shows the average analysis of the two feed products (see Table 1):Precipitation Process.-The pregnant solution obtained by the cyanidation of the above has the following general analysis:-Gold 0·600 dwt. per tonTotal Cyanide 0·050 %Free Cyanide 0·045 %Calcium Oxide 0·015 %KCNS 0·060 %Na2S20S 0·140 %CaS04 0·200 %Cu 0·050 %Zn 0·004 0/0K4Fe (CN) 6 NilThis solution, after standard clarification, is precipitated by means of zinc dust and a soluble lead salt.

Jan 1, 1939

By Stephen Tadolini

A unique circumstance created by monitoring a pre-driven longwall recovery room permitted measuring the stresses of a coal pillar throughout its entire life cycle in less than a week. A fender pillar, created in approximately the middle of a longwall panel at a depth of 650 ft, transformed from a solid barrier pillar - to a yielding pillar - to a residual pillar as 3 ft slices were methodically removed with the longwall shearer. The complete transformation, or life cycle, took place in less than 12 hours. The stresses were quickly transferred from the pillar onto the standing pumpable concrete supports and into the outby pillars. Roof to floor closure measurements, combined with the timing of the pillar behavior, provides a detailed look at the uncontrollable convergence of underground mine openings. Pillars remain the most important form of ?primary support? and understanding these life cycles is vital for safe and efficient mine design, in both room and pillar and longwall panel extractions.

Jan 1, 2007

The seams of black coal occurring in Victoria are so disturbed by faulting, wash-outs, thinning, etc., that it is necessary, for the prevention of costly errors in development, that close boring be undertaken so that the correct positions of the shafts, tunnels, main and auxiliary roadways can be set out in order that the area can be economically worked. The State Coal Mine has two boring plants continuously at work, which have given good service for the last twenty-five years.The information supplied herein is merely our experience in boring at the State Coal Mine over an extended period. The type of plant in use is that known as the Victoria Drilling Plant, equipped with an 11 h.p. portable oil engine, using power kerosene as fuel. It was purchased in 1914, complete with mechanism for cable drilling, capable of boring to a depth of 1500 ft. with a guarantee of 1000 ft., with Calyx cutters, boring rods and all necessary equipment for the sum of £1473. The chief mechanical features of the plant are as follows:-The derrick is in the shape of a tripod (see Fig. 1), two of the legs being of steel channel built together to form a frame which, when lowered on to two sets of road wheels, forms a carriage for the transport of a portion of the boring equipment. The third leg is made of oregon in the form of a double bow, with bolts and distance pieces between the wooden sides. The top of this is hinged on to the steel frame, and the bottom is fitted into a cast iron block, having two small wheels to facilitate erection. A rope attached to the cast iron block and to the winch easily...

Jan 1, 1936

By Gilbert A. Wray

This report presents the results of a study of the overturning Stability of Front End Loaders and the development of an Obstacle Detector to warn of Obstacles in the blind regions of the vehicle. The contributing factors have been identified, the FEL stability characteristics have been determined and six overturn warning indicators were fabricated and two were field tested in a mine operation over an extended time period. A simplified overturn indicator, based on the principle of sensing wheel load, was designed, constructed and field tested. The principle was demonstrated to be sound, however, the method of sensing wheel load must be revised. An obstacle detector capable of detecting a man sized target at ranges of two feet to one hundred feet was designed. A "Breadboard" device utilizing existing microwave devices was constructed and tested successfully.

Jan 1, 1977

By George P. Jr Schivley

Looking at the process of drilling rock from the standpoint of the power required, yields an equation that relates Force-on-the-Bit; Torque, to rotate the bit; and bit Angular Speed to the Penetration Rate of the bit; the Area of the hole being drilled and the Specific Fracture Energy of the rock. Specific Fracture Energy and the Compressive Strength of the rock are related.

Jan 1, 1994

By Kazimierz Gwizdala

In the paper the method for estimation of settlement of vertically loaded piles in a group is presented. The method is generally based on the hybrid procedure with non-linear solution for single piles and with interaction between them for the low-strain shear modulus. Some attention is paid to the influence of deformation and strength parameters used in calculations. The applied model is verified in the framework of the research programme carried out recently in the Geotechnical Department of Gdansk Technical University. It concerns monitoring and analysing the settlements of the existing structures on piles. A comparison of calculation and measurements results for two tested buildings is presented as an example.

Jan 1, 2002

AustraliaÆs strong position as an aluminium producer and potential magnesium producer combined with rapid market growth in the automotive industry, proximity to Asia and other natural advantages points to considerable opportunity for downstream processing and manufacture with light metals in this country. Development of a vertically integrated light metals industry in Australia needs to be pursued with vigour, as does the continued development of global strategic alliances through the value adding chain.

Jan 1, 2000

By Michael Hamilton

Mineral resources have been identified at seven properties in the, Middle Fork Judith study area (fig. 1, and table 1). Commodities consist of silver, gold, copper, lead, zinc, and marble. Eleven properties (fig. 1 and table 2) have potential for discovery of silver, copper, lead, zinc, or sapphire resources. Of principle interest are the mineral deposits within contact zones between the Yogo intrusive complex and the surrounding Paleozoic sedimentary rocks. Contact alteration zones along the southern slopes of Yogo Peak have been prospected in a 2- to 3-mi (3.2-to 4.8 -km) long belt within the study area.

Jan 1, 1982

By Henk E. Brassinga

In Rotterdam a number of underground parking facilities have been built and are under development in the inner city, and in the suburbs. These parking facilities are located at already densely built areas. The design of these constructions has to take into account the impact of the building activities and that of the final construction on the surroundings. In this paper some examples of the different building methods of newly realized underground parking facilities are described, and problems that occurred during the construction are pointed out. In the soil conditions as present in Rotterdam the cost effectiveness of underground facilities can be improved by deepening the parking facility, and at the same time reducing the surface area so that the total parking volume remains constant. In this way the total volume of the diaphragm walls and the costs of the project is reduced.

Jan 1, 2006

By Frank K. McIntosh

Bauxite was first discovered in Tennessee, at Chattanooga, in 1906, during the construction of' the McCallie Street tunnel through Missionary Ridge. Several years later, bauxite was found in sinking a well on the Perry or Isabella Stewart property. These and other deposits furnished a substantial tonnage for the abrasive and chemical industries during the years 1906 to, 1920. The search for domestic sources of war material prompted by World War II brought the Tennessee bauxite deposits to the attention of the Bureau of Mines. During the summer of 1942, James S. Cullison and E. Godwin, geologists of the United states Geological Survey, made a survey of the bauxite deposits of the area. In August 1942, Harold B. Ewoldt, a Bureau of Mines engineer, accompanied by the Geological Survey party visited the area and a drilling program was prepared. Drilling was started in November 1942 and continued until March 1943. A total of 2,519.5 feet in 38 holes was drilled on three properties.

Jan 1, 1949