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By E. D. Gardner

The American petroleum industry is supplying the present domestic demand for liquid fuels. Known reserves of petroleum in the ground, however, are limited, and the .cost per barrel of finding new oil pools is increasing. Any deficiencies of domestic production in the near future doubtlessly could be made up by imports: Dependence upon foreign oil for part of our industrial requirements is not necessarily cause for alarm, but in time of war an adequate, dependable, domestic source of liquid fuels is vital to the defense of the country. As a national defense measure, and to insure a future continuous oil supply for our economic machine, it would appear logical to take steps now to develop methods for producing petroleum substitutes within our own borders. This undoubtedly was in the mind of Congress when it passed the Synthetic Liquid Fuels Act (58 stat.190; 30 U. S. C. Sup. Secs. 321-325), Approved April 5, 1944.The title' of the Law reads: An Act authorizing the construction and operation of demonstration plants to produce synthetic liquid fuels from coal, oil shales, agricultural and forestry products, and other substances, in order to aid the prosecution of the war, to conserve and increase the oil resources of the Nation, and for other purposes. Congress authorized $30,000,000 for a 5-year program and directed the Bureau of Mines to carry it out. The part of the program pertaining to oil shale is being conducted on Naval Oil-Shale Reserves Nos. 1 and 3 (fig. 1) at Anvil Points, near Rifle, Colo.

Jan 1, 1948

By Nikhil Dhawan, Shrey Agrawal

India’s most extensive renewable energy expansion program targets 280 GW of solar energy by 2030. Due to the massive generation of photovoltaic waste (expected 34,600 T by 2030), stringent recycling effort to recover metal resources from endof- life PVs is required for resource recovery, circular economy, and subsequent reduction in the environmental impact. The present study investigates the recycling potential of end-of-life silicon solar modules. The feed characterization reveals that most of the values in PV modules are concentrated in the frame (pure Al), Si wafer (72–84% Si, 9–12% Al, and 0.13–0.71% Ag), and electrical connections (Cu wire coated with Sn). The Si and Ag values in the feed were beneficiated using water fluidization, and concentrate with 90% Si and 2% Ag was attained in the underflow concentrate. Ag values were recovered in the form of AgCl by leaching in nitric acid and precipitation. After the purification step, the residue containing 99% Si can be further utilized to fabricate Si wafer and Al-Si alloy. The preliminary cost estimations suggest that the proposed process is economically viable for the recycling of solar panels with the maximum value generated from the AgCl precipitate followed by Al panels and Si wafers.

Nov 14, 2022

By W. H. W. Husband

Rock salt has been mined by the solution method for many years in many countries. Attempts have been made in the past in Canada and various other countries to produce potash by the' same method. However, only Kalium Chemicals Limited (1) has been successful, possibly because the conditions in Saskatchewan are the most favorable conditions to be found so far for the development of a solution mining method for potash. There are significant differences in solution mining of rock salt and solution mining of potash. First, rock salt deposits are relatively pure in respect to soluble minerals, whereas potash is never found in the pure state and contains Substantial amounts of other soluble minerals, particularly rock salt. In comparison to rock salt, much less potash is dissolved and brought to the surface for the same amount of water circulated through the orebody. The amount of water to be evaporated per unit weight of product is a major difference. Much greater amounts of water must be evaporated when producing potash and the treatment of the brine is more complicated because other dissolved salts have to be separated. Secondly, the rock salt deposits, particularly the domes, are much thicker. Bed thickness is of prime importance because it determines the yield of a well and consequently the economics of the process. Furthermore, as rock salt provides a strong roof structure, larger cavities can be developed and this prolongs the life of the rock salt well.

Jan 1, 1971

By A Bird

Gravity gold circuits have an important part in reducing operating costs and maximising recovery in modern gold plants where coarse gold is present in the ore body. The design and selection of equipment has a vital part in the overall effectiveness of the gravity gold circuit. There are a number of associated factors that need to be taken into consideration when selecting the most suitable equipment for gravity gold circuits including occupational health and safety, security and labour requirements. This paper is a case study that outlines the validation behind the design, selection of equipment and subsequent benefits of the recent upgrade of the gravity circuit at the Marvel Loch gold mine with the main component to the upgrade being the installation of a Consep Acacia Reactor. Since the upgrade there has been a significant increase in gravity recovery, which has reduced the amount of gold reporting to the leaching circuit therefore reducing reagent consumption and overall operating costs. There has been an increase in overall gold recovery and therefore increased gold production. The benefits to occupational health and safety include the removal of toxic gases being released in the gold room during the previous practice of gold concentrate calcination and the removal of the arsenic and nickel from the gold doré, which poses a risk during refining. Manual handling and security has improved as there is no physical contact with gold concentrates during the automated process using the Acacia reactor. The total time for gold room personnel working in the gold room has also reduced from around six hours per day to less than one hour per day.With the continuing development of low grade gold deposits, there will be an increase in demand for low capital, high recovery gravity gold circuits that can significantly increase overall production while reducing operating costs.

Aug 8, 2011

By J. Koponen, K. S. Stadler, A. Fuerst, S. Gaulocher, Th. von Hoff, R. Veldsman

"Gearless mill drives (GMDs) are the workhorse in the mineral processing industries, more specifically when it comes to grinding crushed ore and cement (in various production stages) in semiautogenous (SAG) mills and large ball mills. They are renowned for their excellent reliability and robustness, long lifespan, and little need for maintenance, and thus yield a low total cost of ownership (TCO).A GMD represents a major investment for a mineral processing plant, and its availability is pivotal for the grinding process. As a basic rule, shut-down periods are to be minimized, but even much more important is that unscheduled shut-downs be avoided. In this contribution, we will present a portfolio of innovative remote diagnostic that consist of the following three key components:1. Trouble shooting is a form of corrective maintenance and is based on state-of-the art remote access technology, thus enabling highly skilled engineers to access the current sensor readings anytime and from anywhere in order to resolve urgent problems together with the GMD user.2. Periodic maintenance reports are a form of preventive and predictive maintenance and aim at continuous improvement based on long-term historical records and analyses of multiple measured signals. These detailed reports highlight the health and operational status of the GMD and are periodically (e.g. 3 months) submitted to the customer.3. Remote condition monitoring spans across preventive and predictive maintenance and is based on continuous recording and automatic analyses of relevant signals using advanced algorithms. The main issue is how to handle the enormous flood of data in an intelligent manner. The results of these analyses are made available to both the GMD user and supplier in real time in order to increase the availability and reliability of the GMD.In this paper, we consider various parts of the GMD, e.g. the cycloconverter, the ring motor, the auxiliary devices (e.g. cooling and lubrication systems), and also phenomena related to the mill itself (e.g. state and quantity of charge). The signal analysis techniques range from simple threshold-based analyses to complex time and frequency domain analyses. We will illustrate the benefits of the proposed approaches with some selected examples."

Jan 1, 2012

By R. C. A. Thurston

AT A FATIGUE SESSION organised by the A.S.T.M. in 1949, R. E. Peterson presented a brief introductory paper ( 1) in which lie referred to a discussion on the fatigue of metals which took place in England in 1849, and then proceeded to review some of the subsequent researches concerning the mechanism of fatigue. In the course of the review, he discussed metallograpl1ic studies with single crystals and polycrystalline materials, studies with X-ray methods, and the application of the electron microscope. During that hundred-year period considerable progress was made toward a better under-standing of the nature of fatigue, although it is probable that even greater attention was directed to the more practical aspects of the problem, such as the effects of notches, temperature, corrosion, surface treatment, residual stresses, and so on. Since then there has been an appreciable acceleration in the tempo of the fundamental work, partly influenced by the rapid development of the theory of dislocations, with the result that our knowledge of the mechanism of slip, the initiation of fatigue cracks, and their subsequent propagation, has still further advanced, although it is by no means complete as yet. The present paper is an attempt to out-line the more recent developments in these basic studies, to correlate them when possible, and to draw attention to those directions in which research might profitably be pursued.

Jan 1, 1957

By P. M. Tait, N. A. Warner

"The refining of thermally produced zinc is currently performed using a highly energy intensive and arguably outmoded process, distilling zinc under atmospheric pressure at temperatures of 900°C to 1000°C. In order to produce refined zinc more profitably and with less environmental impact a new process has been proposed. This process is generic to all thermal zinc smelters and aims to match the purity of zinc from current technology (99.99%-99.999%). The objective is to perform all separation processes using only the heat contained in the smelter product stream. Vacuum conditions are extensively used lowering operating temperatures and enhancing separations. As part of this process zinc is distilled under vacuum from high concentration obtaining a refined product with respect to lead content. A mathematical model has been developed from fundamental principles to describe this stage, the distillation of zinc across a temperature difference between two circulating zinc streams in open channels under vacuum. Heat for the distillation is supplied by the liquid phase, necessitating a large recycle to maintain high operating temperatures, and keep zinc concentrations high. In determining this model and the operating conditions required, relationships between temperature, pressure and composition are considered.IntroductionCurrent technology (the Refluxer) used to refine thermally produced zinc is both expensive and highly inefficient. At present 80% of the worlds zinc is produced via the electrolytic process reflecting the poorer performance of the thermal route, the zinc-lead blast furnace and Refluxer. A new process is proposed to overcome the drawbacks of current processes. These drawbacks are both economic and environmental. The Refluxer requires 6.6 GJ of energy to refine one tonne of SHG zinc 1, other disadvantages of the Refluxer stem from high operating temperature, around 900°C, and liquid zinc being highly corrosive towards ferrous metals. The Refluxer is constructed from silicon carbide sections which join together by means of flat machined faces making liquid metal leaks inevitable. The Refluxer columns are very sensitive to thermal cycling, thermal shock and mechanical vibration, which easily lead to structural failure. To avoid thermal stress on the columns the feed rate and feed temperature need to be kept constant which means the feed baths to the columns must be able to accept solid and liquid feed as the Refluxer has to operate when the smelter is shut down."

Jan 1, 1998

By R. J. Sweigard

Deep tillage is used widely as a Means of alleviating excessive soil compaction. There has been some concern that the voids created by deep tillage may collapse before a more natural soil structure develops, resulting in recompaction subsequent to deep tillage. A laboratory investigation was conducted to determine the feasibility of pneumatically injecting organic material into the voids during deep tillage to prevent any significant recompaction from occurring. Various amendments were injected into the soil in the laboratory using a small-scale ripping and injection system. Measurements were made of selected soil properties to evaluate the feasibility of this method.

Jan 1, 1993

The Chamber of Minerals and Energy of Western Australia Inc (CME) is the peak resources sector representative body in Western Australia. The paper gives a summary of the role and objectives of the CME, including its history, structure and key program areas. Particular attention is given to the role of the CME in the Eastern Goldfields of Western Australia. The paper details the types of CME membership that are currently in existence. The paper argues that a strong and vibrant CME is vital to secure the resources sectorÆs growth and development in future years.

Jan 1, 2006

By Karl J. C. Harries

"5.1. INTRODUCTIONThis chapter is intended as a general overview of the subject of royalties between private parties – royalties extracted by governments are not dealt with. This same subject is covered in detail in Volume II, which critiques many sample provisions taken from agreements, giving both pros and cons. If you find something that interests you in this chapter, check Volume II for extra information. Detailed cross-referencing to Volume II has not been attempted, however, most subjects mentioned in this Chapter will also appear in Volume II, usually in greater detail. Reference should be made to the Index.A Brief History of Royalties1In the early days of mining in Canada, the tendency was to sell a claim for cash and to move on, using the stake to look for and stake more prospects. As prospectors became more sophisticated and Canada’s North opened up, the market for properties and the number of mining properties available increased dramatically. Speculation and the practice of consolidating several small properties into one large holding entity became common. In “hot” areas, the speculators2 could far outnumber the prospectors, many of the former having little or no prospecting expertise but lots of market and promotional savvy. However, to consolidate a number of small parcels into one large project can be expensive, and many of the parcel owners became interested in keeping a share in the project, rather than giving up everything. Speculators who were trying to consolidate small parcels wanted to minimize cash payments to parcel holders (usually they did not have much cash and preferred it flowing in their direction rather than away from them). Accordingly, non-cash transactions were developed to meet the aspirations of both owners and speculators."

Jan 1, 2003

By J. Sachweh

The last few years have shown a significant increase in the demands for fine products, which means everything under 10µm. There are more and more applications requesting extremely fine ground powders leading to the development of several milling machines which are better adapted to the new products. Cost saving machinery is important for the worldwide competition. Especially the energy consumption is extremely important for any fine ground product. A worthwhile field for mechanical engineering companies is the dry milling machinery as there are not as many solutions available compared with wet milling applications. In many cases wet mil-ling is the only solution to reach the requested quality, but there are also a lot of applications which can be performed in a dry way on the premise that the right mill and classifier are available. Dry milling permits to save energy and allows to influence the particle size distribution more easily, as a classifier can be used in that case. This will significantly reduce production costs and can enable the production of new products with better properties. The Tower Mill is well-known already in the field of wet grinding. Recent research work and end user reports have shown clearly that this mill has a lot of advantages compared to a ball mill. Up to now this advantage is limited to wet grinding as only few mills have been used for dry grinding. There is no doubt about the efficiency of dry grinding, but new and improved feeding and discharg-ing systems have to be developed in order to enable the full range of its advantages. Especially the high production capacities are a challenge for mill and classifier designers. The Tower Mill with its special grinding mechanism allows to cope with very high feed rates, because machines with more than 1 MW are available. Improved grinding efficiency will decrease the circulation load through the classifier and also lead to smaller classifier sizes. Together with im-proved mills the classifier can work more efficiently because the feed material is finer. Results of a test center plant production will be shown together with a comparison between stan-dard machinery and the MaxxMill®. Preferential applications for each mill will be explained.

Jan 1, 2014

By Edward E. Johnson

The Bureau of Mines publishes in its ?Minerals Yearbook? a series of indexes on the domestic minerals industry. Among these are the index of physical volume of mineral production, indexes of stocks, and indexes of average unit mine value and implicit unit value, This report describes the material coverage of these indexes and the methods used in their construction. Detailed descriptions are given for several other mineral-oriented indexes regularly published by other government agencies. These descriptions give the index user a better understanding of what each index purports to measure and aids him in selecting the most appropriate index for his purpose.

Jan 1, 1965

By Edward E. Johnson

The Bureau of 'Mines publishes in its ?Minerals Yearbook? a series of indexes on the domestic minerals industry. Among these are the index of physical volume of mineral production, indexes of stocks, and indexes of average unit mine value and implicit unit value, This report describes the material coverage of these indexes and the methods used in their construction. Detailed descriptions are given for several other mineral-oriented indexes regularly published by other government agencies. These descriptions give the index user a better understanding of what each index purports to measure and aids him in selecting the most appropriate index for his purpose.

Jan 1, 1965

By Paul D. Tomlingson

The difficult and often harsh working environment of the mining industry can stress both personnel and equipment to the extreme. Often, the unintended consequences of this environment lead to confrontations between departments, as each goes about its tasks of mining, maintaining or supporting these activities. On occasion, the confrontations may result in criticism of other departments for perceived or real sins or omissions. The offended department may not be able to change the circumstances, but can only complain while frustration persists. The most effective solutions are the actions of the mine manager. By establishing mutually supporting roles of each department and specifying conditions for the interactive conduct of maintenance, the mine manager can better assure that the inherent problems of the mining environment are neutralized.

Jan 1, 2011

By D. V. BURR

THE ORIGINAL HUDSON RIVER TUNNEL. NOT quite forty years ago a man of uncommon character entered New York. He had several hundred thousand dollars earned by railroad building in the Nest. He was not an engineer, but he had ideas of engineering work which he was destined to prove correct.. He introduced new ways of tunneling, but his plans had only one distinguishing feature-they were simply interesting as showing how such work could be done; they added nothing to the science, have never been used since his clay, and never will be used again. Engineers of repute ridiculed his proposition ; he was an Ishmael in the profession. But if engineers looked askance at him, he certainly returned their contempt in the heartiest fashion, and had no hesitancy about expressing his views of them individually and collectively. This worked to. his disadvantage when he afterward tried to raise the means to go on with the work. He found that the opinion of engineers was respected by financiers, and that money would not flow contrary to their advice. While his conception of large constructions was distinguishingly original, much more marked was his method of demonstrating the feasibility of, his schemes. In the present clays of great undertakings it is the custom to make the other man pay for the experiments. But the man from the West had other notions of how the thing ought to be done. Having wonderful confidence in his own ability and in his perception of the task before him, he used up all his own money before seeking outside assistance. By building several hundred,, feet of tunnel he proved the correctness of his theory, and the tunnel then dug forms a part of the present tube. The result-he failed to finish the tunnel. He was blind in

Mar 1, 1908

By S. C. Rhoads

The Bureau of Mines is investigating low-chromium alloy substitutes for type 304 stainless steel (type 304 SS). The purpose of the research is to reduce the chromium content in austenitic stainless steels used for corrosion-resistant applications. Nine Fe-9Cr-12Ni alloys containing additions of 0 to 5 pct Mo, 0 to 2 pct V, and 0 to 2 pct Cu were selected for evaluation. All of the experimental alloys containing 5 pct Mo and an alloy containing 2Mo-2V-2Cu possessed structure and tensile strengths similar to those of type 304 SSe Alloys containing SMo-2V and SMo-2V-2Cu had ac-ceptable welding properties as measured by the Varestraint test. Alloys containing at least 2 pct Mo had cQrrosion resistance comparable to that of type 304 SS in solutions of nitric acid, phosphoric acid, acetic acid, and citric acid. In chlorides, all the experimental alloys were susceptible to localized corrosion and stress corrosion cracking similar to that of type 304 SSe The corrosion properties were established by weight-loss tests, electrochemical polarization tests, and stress-corrosion cracking tests. An Fe-9Cr-12Ni-SMo-2V alloy and an Fe-9Cr-12Ni-SMo-2V-2Cu alloy had a combination of welding properties, tensile properties, and corrosion resistances that were most comparable to those of 304 SS.

Jan 1, 1984

By Steve Kral

As the mining industry watches commodity prices continue to soar, the question on most everyone’s mind is how long will this upcycle last. The con-census among speakers and attendees at the SME Annual Meeting and Exhibit is that this cycle is sustainable. The buzz at the meeting was, of course, the current boom cycle the industry is in. Most agree that China’s huge appetite for mineral commodities is part of the force driving the upturn. But the improving economies of other developing nations also plays a role. However, along with the good times come challenges. Speakers at the keynote session addressed some of the challenges and offered their opinions on the sustainability of the boom.

Jan 1, 2006

By W. Stark

Many developing countries with little or no previous environmental regulation are now promulgating air quality regulations which require facilities to demonstrate compliance with both process parameter based emission limits and ambient air quality standards. For many companies with operations in developing countries, an air quality compliance program at the facility level is lacking and these companies have very little background information to work with in developing a program for assessing and maintaining compliance. This paper will present a methodology for development of a comprehensive air quality compliance program for operations located in developing countries with new environmental regulations. The experiences of the authors in developing an air quality compliance program for a mining operation located in South America will be used as a basis. A program for meeting new air quality requirements can be developed in seven steps. The seven steps are: (1) regulatory review and project scope; (2) design and implementation of a baseline air quality monitoring program; (3) site visit, (4) development of a complete air emission inventory; (5) dispersion modeling; (6) compliance analysis and compliance plan; and (7) project completion.

Jan 1, 1998

By Nickolas J. Themelis

Nearly thirty two million tons of municipal solid wastes (MSW) are combusted annually in over one hundred U.S. Waste-to-Energy (WTE) power plants, thus reducing the use of fuel oil by about 1.6 billion gallons of fuel oil. One of the advanced WTE processes is the 0.9-million ton/y SEMASS facility at Rochester. Mass. Most of the combustion in the three giant combustion chambers occurs while the injected shredded wastes are in suspension, i.e .? in flash combustion mode. The velocity. temperature, and concentration profiles in the SEMASS combustion chamber were simulated by representing the combustible fraction of MSW by the simplified formula C6HIO04 and using the CFD program Fluent to solve the turbulent energy and mass transport equations. After validation against plant data. this model will be used to examine options for increasing the productivity of WTE combustion chambers, such as optimum distribution of primary and secondary air and oxygen enrichment.

Jan 1, 2003

By R. S. Dean

A large metallurgical experiment station at Salt Lake City to house the works of the Bureau of Mines in the intermountain area properly has long been projected. It finally became possible when a Public Works Allotment of $300,000 was set aside for building and equipment. With the new building assured, the Bureau of Mines decided to move the headquarters of its Metallurgical Division from Washington, D. C., to Salt Lake City, Utah. It was felt that this move would simplify they administrative work of the chief engineer of the division, as all stations devoted primarily to metallurgical work are west of the Mississippi. These include Rolla, Mo.; Minneapolis, Minn.; Pullman, Wash.; Reno, Nev.; Berkeley, Calif.; Boulder City, Nev.; and Tucson, Ariz. In addition to these stations will groups, of investigators working on metallurgical problem, are maintained at Pittsburgh, Pa., and College Park, Md. Salt Like City was clearly a more central point for the direction of this scattered work than Washington, D. C. The building (fig. 1, A and B) was designed from general plans worked out by the authors of this paper. Contraction was begun in March of 1939, and by the end of the year the Metallurgical Division had moved, into its now quarters.

Jan 1, 1940