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By I. K. Choi

In a recent paper by Smith and Wen(1) the adsorption of sodium dodecylsulfate and trimethyldodecylammonium chloride on kaolinite was studied. As would be expected considering the general negative character of kaolinite, except perhaps at quite' acid pH values (2,3,4), it was found that trimethyldodecylammonium chloride adsorbed strongly on kaolinite at basic pH values. Furthermore, it was found that sodium dodecylsulfate adsorbed strongly on kaolinite at acid pH values, particularly at initial 1H values below pH 3 (final pH values near pH 4). It is interesting to note that adsorption of the anionic surfactant was strong under conditions where the kaolinite was apparently slightly negatively charged (2). The present paper reports on an extension of the work by Smith and Wen. In this paper the effects of the presence of dodecyl alcohol and sodium hexametaphosphate on adsorption of sodium dodecylsulfate and trimethyldodecylammonium chloride on kaolinite are considered.

Jan 1, 1967

By J. Kenneth Wittle

The DC Graphite Melter has been shown to be capable of processing radioactive waste materials. The process is characterized by its high temperature capability and operation in a closed system. From an environmental perspective, the control of emissions coupled with destruction for hazardous organic materials is mandatory. These same characteristics may be applicable to the minerals processing industry. Under normal operation, the system reaches temperatures for nominal operation of 1600°C, with an arc temperature in the order of 5000°C. The system temperature is determined by the melt temperature of the material being processed. In testing of a 750 lb/hour unit, temperatures of 2200°C were reached. Current focus is on finding waste treatment and metals recovery opportunities in the metals processing industry for his innovative technology.

Jan 1, 1999

By M. J. Carlson

With the goal of improving the strength characteristics of pneumatically emplaced material used for localized subsidence control, the binding additives: fly ash, bentonite, and Portland Cement, were examined for their effect on the support capabilities of coal refuse. It was found that, within certain concentration ranges, all three of them offered some increase in the ultimate strength of the backfilling mixture; however, Portland Cement gave the greatest percentage increases. Selection of the appropriate backfilling mixture will allow for the most economical and efficient subsidence control when pneumatic stowing is employed.

Jan 1, 1987

By Fatima-Zahra Houmymid, Elena Chiriotti, Mahdi, Samy

"The Greater Paris projects involves the creation of a 200km extension of the actual public transport network on the close outskirt of Paris. In 2011, SYSTRA has been awarded the Engineering studies of a 20km underground section in the densely urbanized southeast quarter of the Parisian suburb. In order to both guide the TBM technology choice and identify and mitigate the risk due to soil settlement during tunnel boring, several analysis have been carried out and integrated into a Geographical Information System to share and manage this risk during the successive design phases of the project. The geological context‘s complexity and the Owner‘ requirements have led to the necessity of using an innovative analysis approach, leveraging both the numerical modelling analysis’s accuracy and the analytical method‘s ease of programming and implementation in a GIS, by the mean of the calibration of the analytical approach’ parameters on the FEM results.INTRODUCTIONThe Greater Paris Transport Project foresees the extension of the actual public transport network to the close outskirt of Paris through the extension lines 11 and 14, the creation of a circular new line around Paris - line 15 completed by lines 16 and 18 linking developing territories - and line 17 to Roissy-Charlesde- Gaulle airport.The SOCIETE DU GRAND PARIS (SGP) is the public institution that promotes this project and awards SYSTRA as Engineering for the 15th Line southeast section.Line 15th – South-East sectionIn 2011, the Owner SGP (SOCIÉTÉ DU GRAND PARIS) awarded to SYSTRA the preliminary and detailed design of a 20km-long underground section of Line 15, between the stations of Villejuif-Louis-Aragon and Noisy-Champs. The double-track, single-tube tunnel has an inner diameter of 8.5m (about 9.8m excavated diameter, 75m2 excavated cross-section). The tunnel is inserted in a densely urbanized context."

Jan 1, 2016

By J. M. Hird

By blending phosphogypsum with thickened mill clays, Texasgulf has successfully resolved the problems of gypsum disposal and reclamation of mined-over areas. In the process, clays are thickened to 10% solids through high rate thickeners, mixed with gypsum from a drained gypsum pile (75%) and a direct discharge from belt filters (25%), then pumped to mined-over areas. The blending of clays and the low pH gypsum yield a mixture with a pH of about 7. Dewatering is rapid to 40-45% solids within 3 months. The material spreads with very shallow slopes and within a year desiccation by high flotation ditching equipment is possible. The artificial soil is classified as a silty loam in texture, lacking only in nitrogenous nutrients. The soil material has proven to support many field crops including small grain, corn, alfalfa, and grasses. Sycamore, green ash, sweetgum and bald cypress have done well in 3 years of growth. The nitrogen source for tree growth will be made up through an alfalfa cover.

Jan 1, 1993

By Eugene P. Pfleider

The mining industry of the World, and particularly of the United States, has made a complete reversal from underground to surface mining methods since the turn of the 20th Century. This has occurred even as average ore grades were decreasing and strip ratios rising. In the early 1900's there were over 100 underground mines producing from the three iron ranges of Minnesota -- today there are hone. Practically all of our coal prior to 1930 was mined underground; today over one-third is from surface operations and that percentage is increasing. Although world mining has hot changed to surface techniques as rapidly as has the U. S. Industry, the shift is escalating and will approach our figures shortly. A comparison of World and U. S. production figures are shown in Table 1, taken from the AIME Surface Mining volume, and the trend rates for the U. S. are depicted in Fig. 1.

Jan 1, 1968

By J. Andres

"Freeport-McMoRan’s Sierrita operations refines molybdenum disulfide in a ferric chloride leach to remove impurities. To understand bottlenecks in the leach process and the true capacity of the leach system, a cross-functional team was established to look at theoretical models, kinetics of the leaching process, equipment limitations and operational strategies. A series of in-plant tests were run which resulted in a road map for improved throughput. INTRODUCTION Molybdenum, a vital component in the steel industry, is often found in nature as molybdenum disulfide (MoS2). Molybdenum disulfide deposits can exist as standalone components in an ore body, or can also be found within copper porphyry nodes. Processing for these copper/molybdenum porphyry ore bodies involves a first stage of flotation to produce a bulk concentrate before separation of the copper and molybdenum concentrates in a second stage of flotation. In this second stage of flotation, a reagent is added to suppress the copper particles, while allowing the molybdenum disulfide particles to remain hydrophobic and continue to float. This separation is very good at keeping the molybdenum out of the copper concentrate; however a portion of the copper continues to float through the circuit. As a result, there is typically some amount of copper in the final molybdenum concentrate. This copper must be removed in order for the molybdenum disulfide product to meet product quality specifications. Once the raw molybdenum disulfide product has been made, a separate process must be applied to remove any copper, lead, or other impurities remaining in the concentrate. This process usually involves the selective leaching of impurities out of the bulk solid. Gupta mentions three specific types of leaching agents, sodium cyanide, ferric chloride, and hydrochloric acid for the removal of sulfide impurities. Sodium cyanide is useful for the removal of copper compounds such as bornite, covellite, and chalcocite.1 Sodium cyanide solution dissolves these copper compounds, and the remaining molybdenum solids are filtered to produce a pure molybdenum concentrate. Ferric chloride works similar to that of sodium cyanide, but is particularly efficient in removing chalcopyrite and galena compounds. These compounds are easily chlorinated at elevated temperatures, producing copper chloride and lead chloride, through the reactions presented below:"

Jan 1, 2015

By Omar A. Muhtadi, R. Bruce Thorndycraft, David A. Milligan

9.1 INTRODUCTION Precious metals in a leach solution are extracted, concentrated, and purified to complete the process begun in the heap and to produce an end product which will provide an economic payback to the mine developer/operator. Several different processes are required to convert the dissolved precious metals into pure metal bars. This chapter discusses the actual production of metal once it has been recovered from the pregnant leach solutions by the zinc cementation (Merrill -Crowe) or carbon adsorption processes. Metal production is generally taken to mean the production of a fairly pure "dore" bar. This chapter also reiterates some information from Chapter 8 in a slightly different context, since the focus of Chapter 8 was a fairly detailed description of the two actual recovery processes, whereas the focus of this chapter is metal production. The sale of an intermediate precious metal product is possible (as opposed to the production of dore bars at the mine site); however, the value of the precious metals is reduced by the various charges and risks associated with precious metal processing. For this reason, most operators choose to produce the most refined metal possible in order to maximize project economics. Precious metals may be extracted from the leach solution by both conventional and unconventional processes. The conventional processes are activated carbon/electrowinning (ACE) and zinc precipitation (ZIP). The unconventional processes are resin ion exchange, solvent extraction, and direct electrowinning. A typical ACE process has two circulating loops. The first loop adsorbs the cyanide-metal complexes from the dilute leach solution onto the activated carbon. A second, separate solution loop removes the cyanide-metal complexes from the activated carbon into a strong solution, the electrowinning electrolyte. Activated carbon is transferred from one fluid loop to the other. The operating cost of the ACE process is directly proportional to the quantity of carbon stripped and thus to the quantity of precious metal produced. A typical ZIP process contains a single circulating loop. The solution is filtered, deaerated, contacted with zinc, and filtered again. The barren leach solution is then returned to the heap. The zinc sludge recovered in the

Jan 1, 1988

By M. A. Gibson

Ilmenite-rich lunar deposits can be converted to liquid oxygen to support lunar base operations and space transportation propulsion needs by a Carbotek-developed process. Iron oxide in ilmenite is reduced at elevated temperatures by hydrogen in a fluidized-bed reactor to water vapor which is electrolyzed to product oxygen and recycle hydrogen. Reaction rate, thermodynamic equilibrium, and lunar-gravity fluidization behavior are key factors which have been considered. Fluid-solids behavior has been modeled from data taken at lunar gravity conditions aboard NASA KC-135 flights. Large-scale pilot plant operations are planned to complete the development.

Jan 1, 1991

By J. W. MacDonald

PROPERTY AND PRODUCTION: Around 100 Million Tons of Recoverable Coal are available from the approximate 10,000 acres allocated to the mine. Over 1300 acres of surface land holdings extend well beyond the limits required for plant site, storage tracks, water supply reservoir, settling ponds and waste disposal. COAL: Extensive core drilled testing confirmed the early indicated high quality of the #6 Seam Washability data show less than four percent of the' coal seam required removal to provide a superior product for the available market. PREPARATION PANT DESIGN: The limited needs enabled Preparation Plant Design to meet the requirements without inclusion of novel equipment. The simplified needs afforded ample opportunity for considering increased automation where advantage or economy was antioipated. Plant design included protection of opportunity for pre-drying in advance of air cleaning the fine coal and accommodations for addition of Dense Media separating equipment in event warranted or required by future market changes. Protection is also afforded for addition of Raw Coal Storage accommodations in event warranted. Figure I shows the Preparation Plant Flow Sheet.

Jan 1, 1961

By K. Mulukhov

Introduction The depth of open-pit mines continues to increase. The typical designed depth for large quarries is now in the 300 to 600 m (1,000 to 2,000 ft) range, with some quarries even reaching depths of 700 to 800 m (2,300 to 2,600 ft). The cost of handling material from such deep mines can be 60% to 70% of the total cost. The capacity of using a cyclic means of transport, such as trucks or skip hoists, continues to drop as the depth of the mine increases. In addition to the problem of maintaining relatively low slope angles for haul roads, increases in environment pollution and increased fuel consumption make the use of trucks ineffective below 100 to 150 m (300 to 500 ft). In handling large quantities of bulky materials, i.e., more than 15 to 20 Mt/a (16 to 22 million stpy), under fixed terminal points, belt conveyors are preferable in almost in all cases. An exception is when the lump size of the load is too high for the conveyor to handle. Belt conveyors in mines can handle loads having a maximum lump size of no more than 250 to 300 mm (10 to 12 in.). The use of a movable crusher prior to the belt conveyor in an open-pit mine would make the process very expensive. Such an operation could not compete with truck haulage on a cost basis. Belt-car conveyor The main factor that restricts the lump size for conventional belt conveyors is collision impacts between the load-carrying belt and idlers. These impacts are completely eliminated in the belt-car conveyor, which was previously described by Mulukhov (1977). The unique feature of the conveyor is that the load-carrying belt is supported by moving cars. Each car consists of a troughed cross strap that supports the belt with the load and two rollers, on which the cars move along upper and lower rails. Cars are connected by two endless chains revolving over sprockets. The system uses conventional drive pulleys, tail pulleys and return idlers. There are no fasteners between the carrying belt and the car cross straps. The conveyor belt simply drives the cars along by the force of friction between the belt and the straps. A belt-car conveyor was first installed in 1970 at the Karatau mining operation in Kazakhstan. The system was an elevating conveyor with an inclination of 20° and was located on the final part of the truck haul road. The conveyor transferred blasting phosphate ore from the quarry to the crushing plant. A bunker was mounted between the trucks and the conveyor. The maximum lump size was typically 1,200 mm (48 in.). However, there were some lumps as large as 1,500mm (60 in.), which was greater than even the belt width (Fig. 1). Because the prototype belt-car conveyor was intended only for industrial trails, it had a relatively short length of about 50 m (160 ft). Nevertheless, the conveyor yielded a substantial profit over the cost of truck haulage. Naturally, the first question one might ask is why such a system is not now widely used. The reason was the further development of a huge transporting complex for the whole quarry at the base of the belt-car conveyor. After successful industrial trials from 1971 through 1973, which demonstrated the systems engineering feasibility, the State Planning Committee of the USSR included the development of the belt-car conveyor in its plan for the development of the national economy. However, mistakes were made. First, a single organization was not in charge of the development. Second, a plant that was not specialized in belt conveyors was put in charge of the design and manufacturing of the conveyor system. In addition, the crusher was installed before the stacker, which negated the major advantages of the belt-car conveyor. For loading the conveyor, a special blade feeder with pendulum suspension was developed, but it was found unreliable. The main conclusion was that, in-

Jan 1, 2003

By William P. Walsh

In December 1983 the author undertook an investigation in east Texas which was organized to learn the feasibility of applying geophysical techniques over shallow lignite deposits. The work embraced experimental high resolution seismic reflection and offset Wenner resisitivity sounds over three 4 to 4 mile test sections. This site also was sponsored by Woodward-Clyde Consultants (WCC) and a consortium headed by North American Coal Corporation. The principal objective of this investigation was to learn whether the aforementioned geophysical techniques could be applied over shallow lignite deposits (i.e. located at approximately 100' to 300' in depth) and consequently provide structural and stratigraphic information useful for resource and reserve characterization. A secondary objective was to determine if these same techniques could disclose the nature of the overburden and the distribution of ground water therein.

Jan 1, 1985

By R. L. Murray-Smith, M. E. A. Robertson, M. J. Prosser

The AZTEC is an automated instrument, for the non-destructive analysis of gold ore samples, which uses energy dispersive X-ray fluorescence (XRF), This is achieved by X­ray tube excitation of gold K X-rays. The first production instrument was commissioned at Vaal Reefs Chemical Laboratory (VRCL) in November 1987, followed by two second generation instruments in 1989. AZTECs have also been installed at Western Deep Levels and at Anglo American Research Laboratories (AARL). A further unit is being assembled at Ashanti mine, Ghana. At VRCL the AZTECs are used primarily for the evaluation of mine (stope) samples. Each of the production instruments can routinely analyse 650-700 samples per day, with the aid of a robotic sample transfer system. Various techniques have been evaluated for increasing sample throughput. For example, higher value samples can be counted for a shorter time to obtain the necessary relative precision.

Jan 1, 1991

By C. Heckman, M. S. Moats, A. Luyima, W. Cui

"Nucleation and growth of copper on 316L stainless steel from synthetic acidified copper sulfate was studied in the absence and presence of chloride ions and/or organic additives (HydroStar® 4208, DXG®-F7, Cyquest® N-900) using a potentiostatic technique. The current-time data obtained at 0.16V vs. SHE was analyzed using nucleation and growth models. Scanning electron microscope (SEM) images of deposits produced at 300 A m-2 show that the addition of 20 mg/L chloride ions increased the size and reduced the number of copper nuclei. Potentiostatic current-time data from the electrolyte without organic additives indicate progressive nucleation with two-dimensional (2-D) growth under diffusion control. SEM images obtained confirmed progressive nucleation with 2-D growth. 20 mg/L Cl- and 2.5 mg/L organic additives did not change the nucleation and growth mechanism, however the additives increased the number and reduced the size of copper nuclei leading to more uniform coverage of the stainless steel substrate.INTRODUCTION Electrowinning of copper is an important process in the manufacture of high purity copper metal. It is approximated that 20% of the world’s refined copper is produced from acidified copper sulfate solutions by electrowinning (Schlesinger, Sole, and Davenport, 2011). In many plants, copper is electrodeposited on AISI 316L stainless steel substrates for a period of 6-7 days, after which the copper is stripped from the blanks. Even though the deposition time for a commercial copper electrowinning circuit is around one week, it is critically important to control the nucleation, growth, and nature of the initial deposit (Sun and O'Keefe, 1992). Deposit morphology and structure are influenced by the real current density at the electrode surface. The real current density across the cathode surface is made uniform by proper design of the electrowinning cell and electrodes and careful operational practice. Even with good design and control, some current maldistribution occurs. The outcome of severe current maldistribution is poor deposits that affect product quality and/or increase energy consumption. To combat current maldistribution and create a larger operating window in terms of current density, temperature, and copper concentration, small amounts of organic smoothing agents (traditionally guar products) are added to copper electrowinning electrolytes. Moreover, these additives inhibit the growth of copper dendrites, which leads to improved deposit quality by producing bright, smooth, and dense cathodes."

Jan 1, 2015

It is well established that the results of emulsion flotation in which water-insoluble oily collectors are utilized depend critically on the emulsification of the collector and on its conditioning with the pulp prior to flotation. The flotation tests carried out with magnesite and fluorite using sodium oleate as collector confirmed acidic and alkaline ranges of good flotation. While the flotation results in the acidic solutions depend strongly on the conditioning time and can be very much improved when longer conditioning times are utilized, the tests in the alkaline environment do not exhibit any significant dependence on conditioning. The results obtained with sodium salts of myristic and lauric acids confirm these findings. The observed effects provide additional evidence for the role of the colloidal species which appear in the acidic solutions of weak electrolyte type surfactants, such as fatty acids. The flotation properties of sodium oleate in the pH region in which it appears in the form of oleic acid droplets are mainly determined by the properties of such droplets. The flotation in this pH region closely resembles an emulsion flotation.

Jan 1, 1993

"Cast blasting is the primary means of overburden displacement in a surface coal mine. It serves two purposes; fragmenting the rock and throwing it directly to its spoil pile using explosive energy. Increased throw minimizes costs by reducing the amount of material that needs to be re-handled. Prior studies have shown that by only changing blast hole timing with the same blast design, fragmentation and throw alters. It is necessary in cast blasting to optimize both fragmentation and throw, since larger fragments will require more wasted energy to throw the same distance. In an operating mine in Georgia, an optimum inter-hole delay for fragmentation has been found by studying timings from 0ms to 45ms. Instantaneous timing between holes increased the throw by over 100 ft, but fragmentation was poor. Shock and detonation wave collision is a potential reason for this increased throw. This paper investigates this optimized inter-hole timing while altering top and bottom column primer time to potentially improve throw while maintaining optimum fragmentation. Timings studied are top initiation, bottom initiation, and top and bottom simultaneously. INTRODUCTION Explosives are utilized extensively by the mining industry in order to break rock, as either ore or overburden, for hauling, loading, and crushing. An effective production blast strives to achieve optimum rock fragmentation in order to increase the efficiency and reduce the costs of those downstream operations, while simultaneously meeting environmental regulations. The goal of blasting with respect to fragmentation is, according to Hettinger (2015), “to decrease the average particle size of the fragmented rock without overly increasing fines or, in other words, improve fragmentation.” Additionally, the distance the rock is transported by the explosive energy from the blast, also known as throw, can increase efficiency by reducing the amount of material that is re-handled by mine equipment. The primary situation in which this is desirable is the cast blasting of overburden across the narrow pit of a surface coal mine. A key variable in a blast design pattern that can be manipulated to optimize both fragmentation and throw is delay timing between detonations. The invention and increased utilization of electronic detonators has allowed for precise delay timings to be used between rows, holes, and even multiple primers within the same hole. These recent developments in the blasting community have also provided an opportunity to investigate whether or not the mechanism of shock or detonation wave collisions caused by short timing delays are responsible for any increased fragmentation or throw. This experiment attempts to demonstrate if an increase in throw can be achieved while maintaining optimum fragmentation. This study consisted of 3 full scale bench blasts at a granite quarry in Talbotton, GA. Each blast was characterized by the timing delay between the top and bottom primer in the blast column of each hole; one simultaneous blast with a 0 ms delay, a bottom-initiated blast with a 1 ms delay, and a top-initiated blast with a 1 ms delay. Fragmentation analysis of the resultant muckpiles was performed using a combination of the PortaMetrics handheld point-and-shoot rugged tablet from Motion Metrics and the software WipFrag from WipWare. Throw was measured by placing strategic distance markers on the floor of the bench and then taking overhead photographs of the muckpiles after each blast. High-speed video footage was captured of each blast using an MREL Blaster’s Ranger II camera."

Jan 1, 2017

By Rodney R. Krause

In attempting to tell the general public about the coal industry's land reclamation efforts, we have often said, "We're not doing things by the book, because we're still writing it." Like any good catchphrase, the statement is not only striking but true. It is particularly true in the mountains of Appalachia, where the problems of mining; and of reclamation are made more intense by the nature of the terrain. Mining and reclaiming the land "by the book' --which is to say by the methods of contour mining traditionally used in hill country--hasn't worked too well. So a lot of conscientious coal operators and associations are trying new methods--new ways of mining, new machines for seeding and planting, and new species to seed. Not all their experience can be transplanted to other areas, and of course I don't believe that Appalachia is the only place where new methods are being developed. Nevertheless, there's enough action in Appalachia to make a detailed examination rewarding, so let's focus on the hills to see what's new.

Jan 1, 1970

By L. S. Rubin

The efficient and acceptable disposal of fine coal refuse (28MxO) is one of the highest priority problems facing the coal industry today. For many years the established system for the disposal of this fine refuse slurry has been to concentrate the solids in a static thickener and pump the resulting 20-40% solids underflow to lagoons or impoundments. Although this technique has served the coal industry well, increasing environmental concerns and refuse related disasters, such as Buffalo Creek, West Virginia and Aberfan, Wales, Great Britain have resulted in federal and state regulations which now control fine refuse disposal methods. As a consequence of these regulations, the capital costs of constructing, maintaining, and operating regulatory complying impoundments has become in many cases economically unattractive. Areas processing topologies similar to those coal preparation plants of the Appalachians are particularly burdened by these regulations and are consequently turning to alternatives for handling and disposal of their fine coal refuse. The basic requirements of impoundment alternatives as defined by environmental and plant demands are: (1) A relatively solids-free liquid (1000 ppm or less) to serve as plant make-up water in a "closed circuit" system, and (2) a sufficiently dewatered solids product which can be combined with the coarse refuse to form a compactable stable land-fill.

Jan 1, 1978

By P. Albert Carpenter, Wallace B. Howe, Michael N. Greeley, E. C. Bingler, Gilbert R. Eakins, Christy Bell, John Callahan, Gary B. Glass, T. J. Crabs

Although gold's market price dropped considerably from 1980's all time high, exploration for the precious metal remained a particularly bright spot last year, especially in the western US. For example, in Nevada-the nation's largest gold producer-further exploratory drilling at Louisiana Land & Explorations Co.'s deposit at Round Mountain and Newmont Mining Corp.'s find near Carlin resulted in sharp boosts in estimated reserves at both sites. Louisiana Land said its deposit is well on the way to being one of the largest gold reserves in the US. Based on further drilling, Newmont said its Gold Quarry property near Carlin could now produce 4.7-6.2 t/a (150,000-200,000 oz/ year). Reserves at Newmont's two properties near Carlin and a third property in southeast California are reportedly at least 218 t (7 million oz), up from the previously announced 128 t (4.1 million oz). Gold exploration activities were brisk in many other states, including a noticeable effort to explore and reopen dormant properties. Although the return on investments didn't appear as favorable last year as they did in 1980, the gold price was apparently sufficient to spur healthy exploration activity. Outside precious metals, market conditions, and subsequent exploration activity, appeared much more bleak. In the molybdenum market, for example, prices continued to slide, and Amax Inc. tightened its exploration budget. (Amax supplies 60% of the domestic market and 45% of the world demand for molybdenum.) The company spent 16% less on exploration during the first six months in 1981, compared to the same period in 1980. Copper and many other base metal producers appeared in similar straits throughout the year. Uranium exploration activities continued to suffer last year also due to depressed market conditions. Among others, Gulf Minerals Resources and Amoco Minerals Co. suspended uranium exploration activities in the West. Despite current unfavorable conditions, some companies continue uranium searches, confident that market conditions will rebound. On a brighter note, interest in exploring for some industrial and strategic minerals appeared on the upswing last year. Minerals used for oil and gas drilling, such as barite and special sands, were especially noteworthy. In geophysical activity, significant developments were achieved for electromagnetic techniques in both frequency-domain and time-domain systems. Geophysical logging activity declined due to decreased uranium exploration, and computer hardware continued to impact the way mining geophysical data are being acquired. Many presentations and papers were given last year to help exploration geochemists develop new techniques to locate concealed ore bodies. Among techniques described were statistical and computer modeling for enhancing anomalies over blind deposits.

Jan 5, 1982

By T. J. Malterer

Peat has unique physical, chemical, and biological properties. These include high porosity and water retention, high absorption and adsorption properties, high buffering capacity, and it is a rich medium for microorganism activity. Peat has traditionally been used for horticultural purposes. However, in recent years, peat is increasingly being used for waste treatment purposes. This paper reviews North American literature on the use of peat for waste treatment applications. The literature indicates promising use of peat in treating municipal and on-site effluent, removal of low concentrations of heavy metals from wastewaters, and adsorption of liquid and gaseous hydrocarbon pollutants.

Jan 1, 1995