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The subject of steel wire ropes covers such a wide range of points that it would be impossible to deal with it fully in one paper, and in view of the apparent scarcity of published information on the subject it is proposed in this paper to deal with those items which should give the mining engineer a better understanding of the basic factors which affect the design.selection, and use of ropes. The matter will be considered under the following headings:-1. Brief history of steel wire rope-making.2. Rope-making terms.3. Wire rope materials.4. Characteristics affecting economy, operating life, and serviceability of a rope.5. Properties of construction of rope, and stresses met with in wire ropes.6. Drum and sheave sizes and sheave bearing pressures.7. Storage, handling, and maintenance of ropes in service.8. Common factors affecting rope life, particularly winding and haulage ropes.9. Inspection of ropes.GENERALWire rope, which was invented for, and first applied to mine winding, has become an indispensable aUXiliary throughout the whole field of mining, be it for underground, open cut, or dredge work, as well as the requirements of transport and treatment of ores.Though wire ropes appear simple collections of wire and fibre, the demands made upon them are many, and the stresses and abuses to which they are exposed in service are varying, and often of serious dimensions.The exposition of these stresses and abuses, particularly dynamic stressing, corrosion, etc., all of which seriously affect the safety and economical life of the ropes, is often enough to frighten most practising mine staffs, who are aware that before the requirements of economic operation stands the still more important question of safety in mining.

Jan 1, 1947

By W. M. Armstrong

This paper compares research on development efforts in various countries, consideration being given to gross expenditures, manpower involved, source of funds, sector of performance and type of activity. The Canadian R & D activity is then reviewed, particularly as applied to the industrial sector, the problems of applied research in Canada are discussed and some remedies are suggested.

Jan 1, 1968

By D. L. Pool

To increase metal recoveries and to minimize pollution by improved extraction technology, the Bureau of Mines investigated a hydrometallurgical technique to recover copper, lead, nickel, and cobalt from lead smelter mattes. The metals were converted from insoluble sulfides to soluble chlorides using a HCI-CI2-02 leaching system. Parameters studied in a 50-gallon, glass-lined reactor were the ratio of hydrochloric acid to chlorine, chlorine consumption per pound of matte, oxygen reaction pressure, and temperature. The matte material used contained, in percent, 19.7 Cu, 52 Pb, 2.9 Ni, 1.5 Fe, 0.38 Co, 0.19 As, 0.41 Zn, and 0.12 Cd. Extraction of Cu, Pb, Ni, Co, and Cd ranged from 92 to 98 pct, with concomitant extractions of Fe and As of <0.1 pct. The Cu and Pb were recovered as electrowon metals, while the Ni, Co, and Cd were recovered as mixed hydroxides.

Jan 1, 1981

By A. W. Schlechten, W. J. Kroll

As this paper is written, the only method for the commercial production of lithium metal is by the fusion electrolysis of LiCl-KCl mixtures, as first proposed by Guntz.2 The details of the industrial process have not been made public but Osborg8 stated that an efficiency of more than go pct is obtained with a lithium metal recovery above 95 pct and that the metal is 99.5 pct pure. Pletenev9 gave a power consumption of 66 kw-hr per kilogram of lithium metal produced with a salt consumption of 9 kg of LiCl and 0.4 kg of KCI. Pletenev&apos;s figures indicate a somewhat lower recovery than that given by Osborg. In a recent report on German lithium plants, Motock7 gives figures that are also less favorable than those reported by Osborg. At the German plants the lithium recovery in electrolysis was only 83.4 pct, with a power consumption of too kw-hr per kilogram of lithium. The metal averaged only 97 pct pure, with sodium and potassium as the chief impurities. The presence of SO2, SO3, Si02, Ba, Ca, and appreciable amounts of Na and Fe2O3 were especially disturbing in the electrolysis, and it was necessary to run the cell for some time to eliminate most of these impurities and condition the bath. It may be noted here that most of these impurities do not interfere with a thermal reduction process. These facts show that the present method of producing lithium is fairly efficient and would suggest that other methods could not compete. However, fusion electrolysis has certain drawbacks, such as the necessity of supplying costly, low-voltage direct current and of collecting and processing the anodic chlorine if it is not to be wasted. An even greater disadvantage is that lithium chloride must be used for an electrolyte. It is one of the most expensive salts of lithium, since it cannot be produced in anhydrous form by precipitation from aqueous solution, as is done with LiF or Li2CO3. The reduction of lithium by a vacuum process similar to the ferrosilicon method for the production of magnesium would have certain advantages. Small units, such as Pidgeon retorts, would give flexibility of production to meet demand, and a small plant would require moderate capital outlay. There is a possibility of using idle Government-owned magnesium plants for such purposes. The raw materials needed for vacuum thermal reduction would not have to be extremely pure, especially with respect to the iron and calcium content. This paper describes a series of experiments to determine the effectiveness of various agents for the reduction of lithium compounds. The investigation is part of a program of vacuum metallurgy con-

Jan 1, 1947

THE Nominating Committee appointed at the Division meeting in October and consisting of Frank A. Herald, A. W. Peake, C. R. McCollom, Joseph Jensen, H. W. Camp, C. P. Watson, F. Julius Fohs, George Otis Smith, J. B. Umpleby, J. M. Lovejoy and A. W. Ambrose, have presented the following ticket for the year 1929: Chairman, Joseph B. Umpleby; associate chairman, A. C. Rubel; secretary-treasurer, R. Van A. Mills; vice-chairman for Economics, Warren A.. Sinshein~er; vice-chairman for Engineering Education, H. C. George; vice-chairman for Engineering Research, Harry H. Hill; vice-chairman for Production, C. P. Watson;vice-chairman for Refinery Engineering, A. D. David. For Production Engineering Charles V. Millikan. is named vicechairman, with ,Charles E. Beecher, Glenn D. Robertson and W. W. Scott as associate vice-chairmen. The Executive Committee named is to consist of Joseph B. Umpleby, chairman with A. W. Ambrose, Charles E. Beecher, A. D. David, Glenn D. Robertson, H. C. George, Harry H. Hill, John M. Lovejoy, Charles V. Millikan, R. Van A. Mills, Earl Oliver, A. W. Peake, A. C. Rubel, W. W. Scott, Warren A. Sinsheimer and .C. P. Watson, members. Ballots will be mailed to members of the Division.

Jan 1, 1928

By Henk L. C. Meuzelaar

Most of us are aware of the relationship between the golden-yellow resin spots on Upper Cretaceous Wasatch Plateau coals and fossil tree resins (?amber?). Nevertheless, confusion remains about the exact chemical composition and structure of commercial coal resin preparations as well as their observed heterogeneity. In order to arrive at a more detailed chemical description we need to distinguish between micropetrographic, organic geochemical and process technological definitions of coal resins, which may include substantial quantities of constituents unrelated to fossil tree resins. New information on composition and origin obtained by Curie-point pyrolysis/evaporation in combination with isobutane chemical ionization mass spectrometry, as presented in this paper, points to the presence of four more or less distinct resin components: (1) a sesquiterpenoid polymer; (2) sesqui-and triterpenoid monomers and dimers; (3) a suite of triterpenoid alcohols, ketones and acids; and (4) a series of increasingly aromatized hydrocarbons with naphthalene and picene type skeletons. Moreover, a strong similarity is found between the composition of recent Dammar resin and fossil Wasatch Plateau coal resins. Some of the technological implications of these findings and the consequent need for a more precise chemical definition and nomenclature are discussed.

Jan 1, 1990

By M. J. Ankeny, J. J. Forbes

"One of the main functions of the U. S. Bureau of Mines, as authorized by Congress, is to investigate safety and health conditions, to disseminate information regarding safe and unsafe practices in mining, and to aid in improving safety and health conditions of mining communities and in promoting the welfare of the miner. Among several methods of reaching the miner and interesting him in safety work, perhaps the most effective is through the 11 mine safety stations and 11 railroad cars known as mine rescue, or more correctly, mine safety cars.Frequently, the Bureau of Mines receives requests for information regarding the purpose, equipment, personnel, and construction of its safety cars used in the field service. It is the intention of this circular to present to the mining public in particular, and to the public in general, some definite information regarding these safety cars and their functions.The cars are operated throughout the mining fields of the United States and are headquartered as follows (see fig. 1): Car 1, Reno, Nev.; Car 2, Raton, N. M.; Car 3, Pittsburgh, Pa.; Car 4, Terre Haute, Ind.; Car 5, Pineville, Ky.; Car 6, Pittsburg, Kans.; Car 7, Huntington, W. Va.; Car 8, Duluth, Minn.; Car 9, Butte, Mont.; Car 10, Des Moines, Iowa; Car 11, Anchorage, Alaska.One of the most important purposes of the U. S. Bureau of Mines safety cars is to render service at mine fires and explosions where human life is endangered. State mine inspectors and other interested persons are supplied with itineraries of the car operating in their districts from time to time, so that they may know at all times where the car can be found in case of emergency. When these disasters occur the car may be reached direct or through its field headquarters, and upon receiving word of a mine disaster, or request for assistance, it immediately proceeds to the scene of trouble. Frequently a special locomotive is supplied by the railroads and in many instances the movement of the car is given the right of way over all other railway traffic. Upon reaching the destination, the facilities and personnel of the car are immediately available for rescue and recovery operations.Following most mine disasters a thorough investigation is made by engineers of the Bureau of Mines, and a confidential report is submitted to the operator. The information gained in this manner from a large number of mine fires and explosions, together with the knowledge gained from the experimental work carried on at the Experimental mine of the bureau at Bruceton, Pa., serves as a basis upon which the bureau is able to recommend preventive measures whereby similar occurrences may be averted. The bureau car is often used as headquarters for the investigating engineer when such an examination is being made."

Mar 1, 1931

By Wilson Blake

Increased application and interest in the use of microseismic monitoring to deal with ground control problems, Particularly those resulting in violent failures, has brought about the need for practical guidelines with respect to all phases of microseismic monitoring. This report presents the results of an 18-month effort to review the microseismic method and develop needed practical guidelines. Microseismic activity and properties of microseismic events are treated so that these parameters can be taken into account when developing monitoring equipment. Microseismic equipment is discussed to provide familiarization with the components of monitoring systems. Factors to be considered and procedures for developing a microseismic monitoring system are presented. Both physical and electrical considerations for the installation of a monitoring system are discussed in detail. The operation of a microseismic system including data analysis procedures is presented. Field examples to illustrate use of microseismic data in evaluating ground control problems are presented in a number of case histories.

Jan 1, 1982

By A. M. Gavdin, F. W. Bowdish

Mineral dressing is an industrial art concerned with the treatment and separation of solids suspended in fluids. Knowledge and evaluation of the area of solid-fluid interface is important in all cases except those involving only large pieces of solid. In fact, many problems relating to comminution, to flotation, to thickening and classification, could be dealt with more rationally if the interfacial area were known. A number of methods have been proposed for the measurement of the surface of certain finely divided solids. Among them are methods using rate of dissolution of the solid,? its magnetic remanence,³ the turbidity of its suspension," and the character of the size distribution of the material.9 The first two are limited to one mineralogical species per sample; the third has certain optical limitations, especially for mineral mixtures, and the fourth is based on an extrapolation of uncertain validity. The need of a better and more general method of surface determination has long been felt, therefore. The method of P. H. Emmett,4 based upon the low-temperature adsorption of vapors, appears to fulfill this need. This method consists in determining the amount of nitrogen that is adsorbed by a given sample of solid at the temperature of boiling nitrogen. The more surface there is on the solid—both internal and external—the more nitrogen is abstracted. In actual operation, the method is somewhat less simple than has been stated so far, in that the nitrogen is adsorbed in an incomplete layer, the completeness and thickness of the layer being related to the pressure of the nitrogen in contact with the sample.2 This circumstance makes it necessary to determine the nitrogen adsorption for three or more values of the nitrogen pressure. Apparatus In the Richards Mineral Dressing Laboratories an Emmett apparatus has been built and tested (Figs. I and 2). A mechanical vacuum pump B and a mercury diffusion pump A work in series to give a high vacuum. The sample, placed in bulb D, can be evacuated by this pump train by suitable operation of the stopcocks in the glass tubing that connects the various parts of the apparatus. C is a McLeod gauge, used to ascertain the order of magnitude of the vacuum obtained, and not for accurate pressure measurements. Pressure measurements are made in the mercury manometer F and gas-volume measurements in the gas burette E. Gases are stored in flasks L (nitrogen) and K (helium), arranged so that definite quantities of these gases can be introduced into

Jan 1, 1947

By A. M. Gavdin, F. W. Bowdish

Mineral dressing is an industrial art concerned with the treatment and separation of solids suspended in fluids. Knowledge and evaluation of the area of solid-fluid interface is important in all cases except those involving only large pieces of solid. In fact, many problems relating to comminution, to flotation, to thickening and classification, could be dealt with more rationally if the interfacial area were known. A number of methods have been proposed for the measurement of the surface of certain finely divided solids. Among them are methods using rate of dissolution of the solid,? its magnetic remanence,³ the turbidity of its suspension," and the character of the size distribution of the material.9 The first two are limited to one mineralogical species per sample; the third has certain optical limitations, especially for mineral mixtures, and the fourth is based on an extrapolation of uncertain validity. The need of a better and more general method of surface determination has long been felt, therefore. The method of P. H. Emmett,4 based upon the low-temperature adsorption of vapors, appears to fulfill this need. This method consists in determining the amount of nitrogen that is adsorbed by a given sample of solid at the temperature of boiling nitrogen. The more surface there is on the solid—both internal and external—the more nitrogen is abstracted. In actual operation, the method is somewhat less simple than has been stated so far, in that the nitrogen is adsorbed in an incomplete layer, the completeness and thickness of the layer being related to the pressure of the nitrogen in contact with the sample.2 This circumstance makes it necessary to determine the nitrogen adsorption for three or more values of the nitrogen pressure. Apparatus In the Richards Mineral Dressing Laboratories an Emmett apparatus has been built and tested (Figs. I and 2). A mechanical vacuum pump B and a mercury diffusion pump A work in series to give a high vacuum. The sample, placed in bulb D, can be evacuated by this pump train by suitable operation of the stopcocks in the glass tubing that connects the various parts of the apparatus. C is a McLeod gauge, used to ascertain the order of magnitude of the vacuum obtained, and not for accurate pressure measurements. Pressure measurements are made in the mercury manometer F and gas-volume measurements in the gas burette E. Gases are stored in flasks L (nitrogen) and K (helium), arranged so that definite quantities of these gases can be introduced into

Jan 1, 1947

By N. Mejia, Z. Xiao, D. Fragomini, A. R. Laplante

"The adaptation to platinum-group minerals (PGMs) of a protocol developed to predict gold recovery by gravity is presented. The protocol is based on three different data sets: ore characterization of gravity-recoverable minerals, description of their behaviour in cyclones and ball mills, and performance of recovery units. Examples of these are given. It is shown that the gravity-recoverable PGM (GRPGM) content can be very high. A case study at the Clarabelle mill is presented. Sperrylite is the dominant platinum mineral, and its partition curve is very similar to that of gold, despite its lower density. Its grinding kinetics is significantly higher than for gold. As a result, sperrylite accumulates in finer sizes than native gold, but can still be recovered by gravity or flash flotation. Recovery projections based on gravity recoverable data are presented.BACKGROUNDReliable modeling of gold recovery by gravity or flash flotation from a grinding circuit is based on the ability to describe the properties of gold-bearing particles in the ore, their behaviour in grinding and classification units and the performance of the equipment used for recovery, be it gravity or flotation. This is shown in Figure 1."

Jan 1, 2004

By R. W. Winson

Asbestos is the generic name given to a group of fibrous mineral silicates found in nature. They are all incombustible and can be separated by mechanical means into fibers of various lengths and cross sections, but each differs in chemical composition from the others. The commercial grades of asbestos consist of a spectrum of lengths and sizes and are not definitive as are most organic fibers. It is generally recognized that there are two main groups of asbestos. The first only contains the fibrous serpentine called chrysotile and comprises about 94% of the world production of asbestos. The second group contains five minerals in the amphibole series+rocidolite, amosite, anthophyllite, tremolite, and actinolite. The latter two have no commercial importance. Properties Physical The structures of asbestos fibers have been studied intensively over a number of years. X-ray diffraction patterns have been used as a means of identification and classification. Low angle X-ray scattering techniques have shown that chrysotile fibers are "hexagonally close packed" and parallel to each other, having cross-sectional diameters varying from 18014 to 300A units, while the amphibole fibers are many times larger in cross section. Electron micrographs of the more common types of as- bestos are shown in [Figs. 1-4]. [Fig. 1] illustrates the softness and flexibility of chrysotile which make it suitable for textile-type products. For a number of years there was considerable controversy over the exact nature of chrysotile fiber, but the photographic evidence in [Figs. 5-7] clearly show that it is tubular in structure. The curvature is the result of the mismatch in the dimensions of the silica [Si,O,l and brucite [Mg(OH),] layers which are on the inside and outside, respectively, of a double sheet. This curvature had been predicted by Pauling (1930) years ago based on the molecular dimensions of the two component structures.

Jan 1, 1975

By J. Gartelmann, B. Zaslavsky, Y. Vojta, D. J. Chaiko, W. Mego, A. N. Rollins

"Aqueous biphasic extraction (ABE) processes offer the potential for low-cost, highly selective separations. This countercurrent extraction technique involves selective partitioning of either dissolved solutes or ultrafine particulates between two immiscible aqueous phases. The extraction systems that we have studied are generated by combining an aqueous salt solution with an aqueous polymer solution.We have examined a wide range of applications for ABE, including the treatment of solid and liquid nuclear wastes, decontamination of soils, and processing of mineral ores. We have also conducted fundamental studies of solution microstructure using small angle neutron scattering (SANS). In this chapter we review the physicochemical fundamentals of aqueous biphase formation and discuss the development and scaleup of ABE processes for environmental remediation.IntroductionAqueous biphasic extraction (ABE) is a highly adaptable separation technique that can be used in a wide range of applications. We have been evaluating various types of ABE systems for possible applications in the treatment of solid radioactive wastes (1,2), liquid nuclear wastes (3,4), and contaminated soils (5-7), and in the removal of organics from aqueous salt solutions (8). We have also conducted fundamental studies of the solution microstructure of ABE systems using small angle neutron scattering (SANS) (9).The extraction systems are generated by combining an aqueous salt solution and an aqueous polymer solution. This produces two distinct liquid layers that are as immiscible as oil and water, yet each liquid layer contains at least 70 to 80 wt % water. The biphasic systems that we have been working with consist of immiscible polyethylene glycol (PEG) and salt solutions. Some inorganic salts that promote biphase formation with PEG solutions include the sodium/potassium salts of sulfate, carbonate, phosphate, and hydroxide (10)."

Jan 1, 1996

By J. M. Wempen

As development in underground coal mines progresses away from the critical components of the ventilation system, including the main fans and ventilation shafts, resistance is markedly increased. This results in higher pressure and flow requirements from the main fan(s) to maintain adequate face ventilation, which often requires that the primary ventilation system is upgraded with additional shafts and surface fans. The use of booster fans underground is a potentially practical alternative. This study presents simulations of the use of booster fans in two underground ventilation scenarios, one longwall and one room and pillar. The booster fan effects on the power requirements of the ventilation systems are evaluated.

Jan 1, 2011

By D. H. Gieskieng

THE advent of curved jaw crusher wearing plates made an approach other than segmental layout analysis desirable for prediction of capacities. For some time it had been known that the drawing board capacities of crushers using these plates had to be considerably modified by complicated experience factors to achieve agreement with results. Because these apparent capacities could be readily increased severalfold by minor crushing chamber shape changes, it was necessary that the utmost precaution be taken in predicting capacities of jaw plates modified for nonchoking, special wear characteristics, or any other reason. To this end the laboratory and field tests outlined by the author in a previous paper1 were made on Blake-type jaw crushers. The results of these tests were summarized in a simple first degree equation applicable to crushers using either straight or curved jaw plates. This equation first outlines the maximum capacity potential of a given crusher, then reduces this figure in accordance with installation circumstances by means of a realization factor. It was found subsequently that this equation, with the addition of an eccentric throw factor, is applicable to standard types of single-toggle or overhead eccentric jaw crushers as far as maximum capacity potential is concerned. However, these crushers have realization factor curves somewhat different from those outlined for the Blake type. While this paper is concerned principally with standard type single-toggle crusher capacities, the evaluation of data obtained with these machines is simplified by comparative reduction to the 10 x 7 in. Blake-type equivalents upon which the summary of the preceding paper was made. Convertibility of data from one type of crusher to the other also tends towards confirmation of both. The agreement of these data is sufficient to be considered complimentary. Consequently the feed factors, f, previously reported for Blake crushers are slightly adjusted to an average with the single-toggle crusher results. Blake-type equation: C = f.d.w.y.t.n.a.r [I] Single-toggle type equation: C = f.d.w.y.t.n.a.e.r [21 where C is the capacity in short tons per hour through the crusher, f is a feed factor, dependent upon the presence of fines in the feed, and the surface character of the jaw plates used. Values of f : Smooth Plates Corrugated Plates With normal fines 0.0000414 0.0000319 Fines scalped out 0.0000368 0.0000252 Large pieces only . 0.0000312 0.0000215 d is the apparent density of the broken product in pounds per cubic foot. (If the true specific gravity of the feed is known, 40 pct voids may be assumed and d becomes 37.4 times sp gr). w is the width of crushing chamber in inches. y is the openside setting of the crusher, in inches. In the case of corrugated jaw plates it is measured from the tip of one corrugation to the bottom of the valley opposite. t is the length of jaw stroke in inches at the bottom of the crushing chamber. It is the difference between open and close-side settings. n is rpm, or crushing cycles per minute, a is the nip-angle factor. It is unity for 26" and 3 pct greater for each less nip-angle degree. A nip-angle of 20" has an a value of 1.18, and an angle of 30" has an a value of 0.88, see Fig. 1. r is the realization factor. It is unity for perfectly uniform choke feeding and usually less for actual operating conditions according to the method of feeding used and the probabilities of hang-ups involving the size of feed and crusher opening. Approximate values are given by the curves in Fig. 2. These values are further reduced by intermittent feeding, e is the throw or diameter of gyration of the single-toggle crusher eccentric in inches. As evident in Fig. 1A, variation of feed size will generally have little effect on nip-angle if both jaw plates have flat areas. Jaw plates having continuous curvature, as in Fig. 1B will have different nip-angles, depending upon the size of feed. For test work as described in this paper this effect was accounted. For general compilation of capacities for average feeds it is suggested that the nip-angle be taken at the various settings computed, at an arbitrary level, such as is indicated in Fig. 1C. Data Evaluation To bring the Blake and single-toggle type crusher capacity test results to common terms for evaluation, all data are converted to terms of 10 x 7 in. Blake-type performance at conditions of 100 lb per cu ft, 10 in. chamber width, 250 rpm, 0.65 in. stroke, 3-in. openside setting, and 18° nip-angle. (The nip-angle of the 10x7 in. Blake is 18° at 3-in. setting.) The single-toggle crusher performances are also divided by the eccentric throw to bring this effect to unity. As outlined,&apos; laboratory and field tests made on Blake-type crushers ranging from 10 x 7 in. to 60 x 48 in. were summarized along the foregoing conditions of speed, stroke, etc. This resulted in groups of data which correspond to feeds with fines, feeds

Jan 1, 1952

By J. C. Bradley

The relation of annealing temperature to conductivity of copper wire has been determined. Conductivity hard was 98.26 per cent. After a 10-min. heat,ing at 200" C. it was 98.69. By annealing 10 min. at 300" C. a large increase, to 100.93, occurred. Maximum conductivity, 101.15, was attained after a 500" C. anneal; thereafter it decreased to 100.53 after a 950" C. anneal. If copper is gassed the decrease is much more than this. Material and Method The work was done on high grade electrolytic copper, 99.942 per cent, copper plus silver, silver 0.0008 per cent. It was hot-rolled to 1/4 in., then cold drawn to 0.080 in. The wire was cut into 25 5-ft. lengths and numbered 1 to 25 as cut. Four samples were tested hard. The others were wound into 5-in. diameter coils. For the 100" C. heating a coil was put into water, the water brought to . boiling, and the wire kept at this temperature for 10 min. For the higher temperatures the coils were placed in envelopes of sheet copper, a little water added, and the envelopes sealed by folding over the edges twice, and hammering them together. This kept the air out very well. The envelope and wire were brought to the desired temperature; this was maintained for 10 min., then the whole was water-quenched. Results Data from the tests are shown in the table and plot (see Fig. 1); conductivity is referred to the International Annealed Copper Standard at 20" C. Conductivity hard is considerably less than conductivity soft.1 The increase is sharp when the wire anneals. The maximum, 101.15 per cent, in the particular material used, comes at 500º C.; thereafter the conductivity falls to 100.53 per cent. after 950" C. annealing, a drop of 0.62 per cent.

Jan 1, 1927

By Glenn Kosick, John Starkey, Glenn Dobby

"A practical new test has been developed for SAG hardness determination. Using two kilogram samples of minus one inch diamond drill core or crushed muck samples, the Starkey SAG Test has been shown to give accurate predictive information which directly relates to on-stream SAG mill performance. Typical results and test criteria are discussed in the paperAchievements to date include:• Identification of hardness profiles and the location of hard and soft zones in a large ore body.• Accurate prediction of the hardness of a bulk sample by using an adjacent diamond drill hole.• Derivation of a plotted curve relating pilot plant power to laboratory relative hardness.• Demonstration that for every test done to date, the Starkey SAG Test produced a product size distribution identical to that produced in a pilot plant or full scale plant SAG operation.This test can now be used for blast hardness monitoring and short term control of mine production in existing plants and for identifying the proper locations for bulk samples in new projects. In addition, new SAG mill design can now be rationalized in a low cost way to eliminate unforeseen production shortfalls.IntroductionThis paper is presented to introduce the Starkey SAG Test, a practical new laboratory tool for measuring the relative hardness of small ore samples in a semi-autogenous grinding (SAG) environment. The test was first designed for use on diamond drill core samples during the prefeasibility stage of new mining projects, to provide new information about the ore body at reasonable cost. It is a new tool and does not replace existing pilot plant test requirements.The test will also be useful for throughput prediction in existing SAG plants by assisting in short and long term mine planning, where forecasting of metal grades and milled tonnage is used to control mine profitability. Because in-plant hardness testing has previously been unavailable on small samples, this test offers exciting possibilities for SAG mill operations where hardness variation is or could be a problem.The Starkey SAG Test provides the following benefits to the mining industry"

Jan 1, 1994

By Ma Lijuan, Zhang Yubing, Wang Bo, Sun Huilan

The effect of lime ratio on phase composition and alumina leaching property of MgO-contained calcium aluminate clinker were investigated by analytical reagent, the XRD analysis of its mechanism was discussed. The results showed that: when the sintering temperature was 1350 ℃, C/A was 1.4, A/S was 1.3 and the content of MgO was 4%, the increase of the C/A promoted the formation of C12A7 and restrained the formation of Q-phase. The alumina-leaching ratio of the clinker (A/S was 1.3) was increased from 74.33% to 91.34% when the content of CaO was 5.21%.

Jan 1, 2015

By William C. Baldwin

Unitization and containerization continue to grow with great rapidity throughout the world today. Every industrial nation outside of the Iron Curtain is devoting more and more time toward research of these developing sciences. Unitization and containerization are proving to be the solution to many of modern industry&apos;s most pressing handling and shipping problems. Manufacturers make large savings, carriers receive many benefits, and customers take an increasing interest in demanding that their shipments either be unitized or containerized. Unit-loads consist of items, packages or bulk materials pre-assembled into a convenient mass for handling by mechanized equipment and to fit the internal dimensions of carriers. It has been found that unitized handling and shipping offers cost savings too great to be ignored by anyone interested in the distribution of goods. At present, the benefits from unitized shipping and handling are being enjoyed only to a small extent due to the failure of many persons concerned with handling practices in recognizing only some of the advantages of unitization. Before the full benefits of unitized handling and shipping can be realized, some major changes in packaging and distribution practices will be necessary on the part of industry. Numerous investigations in the last two years show conclusively that there are more advantages and more inherent savings for shipping goods on pallets in unit loads than by any other method. There is no question that unit-load handling can offer significant advantages to the user over piece-by-piece package handling. Reduction in handling costs is the primary objective of such activities, but it is by far not the sole objective. Some of the other benefits that can be realized are:

Jan 1, 1973

By R. J. McLeod

"CONTROL STRATEGYThe Lake Dufault Division of Falconbridge Copper Limited has been concentrating a complex copper zinc ore since late 1964. An ARL X-ray on stream analyzer was installed in 1966 for process control. A Digital Equip-ment Corporation PDP8 was added in 1968 for more complete control. To improve the system the computer was exchanged for a Moded PDP-81 in 1971.The new computer is time sharing with 8K core memory and 32K disc storage. A new interface was installed to accommodate 14 X-ray streams and additional analog signals for process control. The system gave us additional capacity and flexibility to make changes in operating programs and control strategy while on line. As the computer is used for process control a modified focal language was chosen as the operating language for ease of operation. This language is more suitable for process control than for statistical work.The main components of the control system are(a) Computer(b) Interface(c) Production Control X-ray Quantometer(d) Teletype terminals(e)Reagent feeders(f) Sample SystemThe operation of the system consists in the computer selecting the various streams to be analyzed by a PCXQ Quantometer. When the flowing sample is presented to the X-ray the intensities of the various elements are read by the computer from analog to digital converter, the assays are then computed. From the tonnage and assays the computer is programmed to determine the amount of reagent added to various parts of the circuit. The computer drives the feeders via the interface for the required amount of reagent. After following a certain sequence the computer prints out the performance and control data on an ASR35 Teletype. The data is printed out approximately every seven minutes. Any des¬ired changes in the program or strategy can be made during operation via an ASR33 Teletype connected to the computer."

Jan 1, 1973