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By Kenneth K. Humphreys

INTRODUCTION At the time the 4th edition of this book was published in 1979, the coal industry had experienced a sharp upturn in prices for its product. From 1950 throgh 1969, steam coal prices had held almost flat at about $5 US per st (about $5.50/t). Thus, when considering the effects of inflation, the price of coal had actually been declining for two decades. The passage of the Coal Mine Health and Safety Act in 1969 and its cost effects started an upward trend in coal prices which was rapidly accelerated by the effects of the Mid-East oil embargo in 1972. Prices of steam coal on the spot market eventually climbed to over $30 US per st ($33/t) and higher in some cases. Metallurgical coal prices skyrocketed in a similar manner and the industry at long last appeared assured of an adequate return on investment. Many companies did expend large sums of money to upgrade and expand their mining and preparation facilities. Unfortunately the bubble eventually burst, in great measure due to the downturn in the US domestic steel industry and the resultant decline in metallurgical coal demand, loss of export markets to other nations and even imports of large amounts of foreign coal to the United States, and more stringent environmental regulations which made many high sulfur coal measures uneconomical to mine. Compounding the problem was the rapid world decline in oil prices in the mid-1980s which encouraged many consumers to utilize oil rather than coal. During the 1980s, metallurgical coal dropped over 20% in price, which, when considering inflation, actually amounted to about a 40% decrease in value. Export coal decreased a similar amount in price. Steam coal prices held nearly constant, thus also losing considerable value when inflation is considered. All of these factors make it even more imperative than ever that the industry do everything in its power to make wise economic decisions and to examine carefully all existing operations and planned future expenditures to be certain that their full cost implications are understood and that they can be justified on the basis of an adequate return on investment. It cannot be assumed that the price of coal will increase. To the contrary, as indicated previously, when considering inflation, coal decreased in value in the 1980s, just as it also did in the 1950s and 1960s. The price surges in the 1970s merely were a catchup game, and in truth the true market value of coal is in reality even lower than it was in 1950. CAPITAL AND OPERATING COST ESTIMATION Prior to constructing a new plant or expanding existing facilities, a detailed preliminary cost estimate is necessary to determine the capital investment

Jan 1, 1991

By Wufeng Jiang, Jiann-Yang Hwang, Suju Hao, Yuzhu Zhang

Lime was made by the calcination of limestone in a high pressure resistance furnace. The lime mineralogical phases and micro-morphologies was characterized by field emission scanning electron microscopy (FE-SEM). The lime activity degree was determined by acid-base titration, and the lime pore distribution was measured by mercury intrusion porosimetry (MIP). The results show that with the increase of calcination pressure, the lime activity degree is increased, and the lime develops a large pore structure. The desulphurization experiments were carried out in the induction melting furnace using active lime with different activity degrees as a desulfurizer. The results show that the desulfurization performance of lime is closely related to the activity degree. There is a strong positive linear relationship between the desulfurization rate and the lime ’s activity degree.

Mar 1, 2018

Petroleum exploration and development is vitally important for the future well being of Australia. The Australian petroleum exploration/development industry is alive but not so well. A combination of.:factors point to the industry requiring a much more mature effort in both short and longer-term planning to ensure greater success and effectiveness for petroleum discoveries and development. While many petroleum exploration companies are competently run, there are far too many which will be lucky to survive, even though their exploration areas are highly Prospective.

Jan 1, 1983

By John Griffen

DURING the past year, purchases of coal-preparation equipment and the discussions and plant-scale tests conducted indicate that much attention is being given to better recoveries of coal by preparation plants and improved quality of the finer sizes to widen their market. In the anthracite regions the new equipment was predominantly for the cleaning of the steam sizes, much of it for treating No. 4 and No. 5 buckwheat. The units installed were largely coal-washing tables, Hydrotators, and Menzies cone separators.

Jan 1, 1944

By Zhigang Liang

A carbon free precast block was prepared by using high-alumina fused corundum as aggregate and fused magnesia, and ultra-fine Al2O3 and ultra-fine SiO2 powders as matrix materials. A small linear expansion for the precast block was achieved through spinel formation from the reaction of MgO with Al2O3. The precast block showed a lower apparent porosity, higher hot modulus of rupture and better slag corrosion resistance compared to the traditional Al2O3-MgO-C brick. Moreover, the practical application of the precast block to the ladle lining proved it to possess a better thermal insulation which could effectively prevent the temperature drop of molten steel during the refining process. It can be predicted that the carbon free precast block could possibly be accepted as a new type of ladle lining material for the production of low-carbon and ultra-low-carbon steel.

Jan 1, 2009

By P Collier

From 1972 until 1989 when operations were suspended Bougainville Copper Limited (BCL, owned 53.58 per cent by Rio Tinto Limited) operated a large open pit mine and processing facility at Panguna on Bougainville Island, Papua New Guinea producing copper concentrate containing significant quantities of gold and silver.BCL has a stated vision of recommencing operations at Panguna. In 2008, Rio Tinto, on behalf of BCL, conducted a multi-disciplinary study to assess the technical and financial viability of redeveloping the Panguna operation. One of the key outputs of the study was a Joint Ore Reserves Committee (JORC) Code compliant mineral resource statement based on the existing block model and fundamental data, archived since mine closure. Historical data (including the resource block model and drill hole data) was recovered from computer archives by a former Panguna mine employee familiar with the various obsolete data formats, thus maintaining an unbroken chain of custody of the data by Rio Tinto since operations were suspended. No additional data were collected as part of this study.The extensive data and documentation archive facilitated a sufficiently detailed evaluation of the fundamental data and model to support an updated resource statement. Table 1 of the JORC Code was used to guide the model validation process.Reconciliation of blasthole and metallurgical plant data with the reserve model, indicated that the copper and gold drill hole composite database was significantly biased towards underestimation in several key domains due to a combination of the following: mineralisation loss during core loss, core loss (minor), vertical drill holes failing to intersect sufficient subvertical mineralised fractures and veins, drill hole spacing too wide, and variable diamond drill hole core size. The resource model evaluation was based on three material types (all previously mined at Panguna), that were defined based on cut-off grade and rock type parameters: direct feed ore – material for delivery directly to the plant, preconcentration and screening ore – subeconomic material beneficiated to produce fines of economic grade, and waste. Three pit shells and designs were generated based on three separate sets of economic parameters. These economic parameters were also used to assign material types to the block model. The three resulting models were then evaluated against the corresponding pit shells.Classification of the resource was approached conservatively due to the inherent bias in the drill hole data. Consequently only Indicated and Inferred resources were tabulated.The study highlighted the importance of maintaining detailed documentation pertaining to resource estimates and operational history, particularly reconciliation, and the value that can be added by a simple, low-cost data compilation exercise.

Aug 22, 2011

By Z. L. Huang

A new porous apatite product was prepared using phosphorite from Yichang China by a tem-plate-directed method in self-made reaction equipment under constant temperature and pressure. The product was characterized by XRD, FT-IR and SEM. The results showed that the product was a kind of micrometer porous sphere three-dimensionally structured by apatite nanoflakes, that the average thickness of nanoflakes was about 50 nm, that the average pore size was about 1.2 µm and that the particle average size was about 20 µm. Great amounts of Ca2+channel, high special surface area and regular spherical shape show the potential promising applications of this special porous apatite product in the fields of catalyst, medication, chemical engineering and environment engineering

Jan 1, 2014

By Y. Suzuki, J. Nagao, Y. Ueda, K. Shimokawa

"A Ti- Ni intermetallic compound could be formed rapidly from Ti and Ni powder compact with SHS process. Microgravity experiments using a drop shaft are carried out, This report shows the effect of microgravity or high gravity on formability of an intermetallic compound. It is concluded that the specimen forms a porous and nearly amorphous alloy by rapid cooling under microgravity but with rapid cooling under high gravity after microgravity, the specimen forms a uniform and dense structure with better crystallinity.IntroductionTi - Ni inter1etallic co1pounds have been produced and have beco1e si1ilar to the a1orphous and porous structure as a result of the SHS (Self Propagating High-te1perature Synthesis) process under 1icrogravity. SHS process is being applied to the synthesis of cera1ics and inter1etallic co1pounds (1). The technique is characterized by a large a1ount of heat being emitted within a very short ti1e interval as regards the sistering reaction. One SHS process, acco1panying 1elting by a reaction was observed, and that was due to the quick heating of a Ni-Ti co1pact containing 50 ato1ic percent of Ti under a low pressure (2-4). In this report, we have researched the use a drop shaft which is 1ore effective during a short ti1e under 1icrogravity and high-gravity, so as to obtain high dense speci1ens with the exception of porous specimens (5). Mechanical properties of each specimen were esti1ated from these 1icro-structures with a discussion about the effect of changing gravity regarding 1elting and solidification of the Ti-Ni intermetallic comounds."

Jan 1, 1996

By Junli Xu, Xianwei Hu, Kaiyu Xie, Liangxing Li, Zhongning Shi, Zhaowen Wang, Bingliang Gao, Aimin Liu

Al-Ti master alloys were prepared by aluminothermic reduction between the dissolved titanium dioxide and aluminum in cryolite melts at 960oC. The kinetic analysis by differential scanning calorimetry indicated that the apparent activation energy of the reaction of reducing titanium dioxide by aluminium is 22.3 kJ/mol, and the reaction order is 0.5. The products were analyzed by means of X-ray diffraction, X-ray fluorescence, scanning electron microscopy and energy dispersive spectrometer. Results from X-ray diffraction showed that the phase compositions of produced alloys are Al and Al3Ti. In addition, Al-Ti master alloys containing 2-6 mass% Ti were formed at different reduction time of 2-5h in aluminothermic reduction experiment.

Jan 1, 2015

By Mohamad Omarei, S. M. Sadrameli

"The aim of this research work was to produce biodiesel (fatty acid methyl esters, FAME) from canola oil using KOH loaded on y-Al203 support as a heterogeneous catalyst. Different parameters such as effects of the molar ratio of methanol to oil, catalyst amount and reaction time on the yield were investigated. Scanning electron microscope (SEM) and X-ray diffraction (XRD) were used for characterization of the catalysts. A biodiesel yield of 86.67% was obtained under catalyst preparation and transesterification conditions of calcinations temperature of 773 K, 4 h of reaction time at 338 K, and using 3.5 wt% catalysts and molar ratio of methanol/oil of 15:1. The leaching of potassium species in the spent catalyst was observed.1. IntroductionBiodiesel is an eco-friendly and alternative energy source for diesel engines that can be synthesized by transesterfication of vegetable oil or animal fat with alcohols [1 ]. There are four principal approaches to the synthesis of biodiesel involving the transesterification of the triglycerides of the plant oils and animal fats: base catalysis [2], acid catalysis [3-5], employing supercritical alcohol conditions [6] and enzyme catalysis [7]. The commonly used homogeneous catalysts are NaOH, KOH and their alkoxides. Homogeneous alkali-catalyzed transesterification is much faster than acidcatalyzed transesterfication [8]. However, a large amount of water is required to transfer the catalysts from the organic phase to a water phase after the reaction. Therefore, it is considerably more costly to separate the catalyst from the produced solution [9]. These disadvantages could be removed by use of a heterogeneous catalyst [10]. The use of heterogeneous catalysts eliminates the neutralization step, hence it results much easier to separate from liquid products. Also, they can be designed to give a higher activity and selectivity and to have longer catalyst lifetimes [11]. A large number of different heterogeneous catalysts have been synthesized for biodiesel production. For example, calcined Mg-Al hydrotalcites [12], zeolite and metal catalysts [13], metal oxides such as calcium oxide (CaO) [14], magnesium oxide (MgO) [15], zirconium oxide (Zr02) [16], and supported catalysts [17] have been investigated as heterogeneous catalysts. CaO and MgO are most frequently used heterogeneous catalysts for biodiesel production [18]. In this present work, we aimed at developing an efficient catalyst for transesterification of canola oil. We have prepared KOH/ Al203 by impregnation and applied to determine the optimum conditions for biodiesel production. Three different variables including reaction time , alcohol to oil molar ratio and catalyst loading with may influence the quality of the produced biodiesel were optimized. Moreover, SEM (scan electron microscope), XRD (X-ray diffraction) and XRF were used for characterization of the catalysts."

Jan 1, 2012

By Yanjie Liang

Elemental sulfur and volatilization kiln slag(VKS)containing heavy-metal produced by smelter factories were used to produce sulfured building material. The effects of heating mode, material proportion (MSulfur:MVKS), size of waste particles and ratio of aggregate to filler(A/F) on the mechanical properties and leaching toxicities of solidified stuff were investigated. The optimal conditions for the solidification are stepped heating mode, 3:7 ratio of MSulfur to MVKS, particle size less than 150µm and 3/17 ratio of A/F. Under the above optimal conditions, the compressive strength of solidified stuff rises to 35 MPa, and water absorption is down to 4%-6%.Furthermore, when NaOH is applied as an additive in the process of solidification, the 2+concentrations of most heavy metals except Pb have reached the national leaching toxicity standard. The results of X-ray diffraction reveal that sulfured solidification is caused by the physical encapsulation rather than chemical transformation.

Jan 1, 2010

By Chang-Dong Li

Cadmium ingot and nickel powder were prepared by high-temperature distillation, solvent extraction and liquid phase reducing method with spent Cd-Ni batteries as raw material. The impacts of the temperature in the distilling stage, the concentration of H2SO4 in the leaching stage, the pH value in the extracting stage and the dosage of hydrazine in the reducing stage were discussed respectively. The as- prepared samples were characterized by the means of X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic absorption spectrometry (AAS) and inductively coupled plasma-atomic emission spectrometry (ICP-AES). The results showed that the recovering efficiencies of Cd and Ni reach 99.5% and 99.3%, and the purities of Cd ingot and nickel powder were higher than 99.90% and 99.80%, respectively.

Jan 1, 2009

By T. Wajima

"A novel carbonaceous adsorbent for recovery of nickel from nickel plating waste solution was prepared from rice straw using sulfur impregnation. The rice straws were cut to 1 cm pieces, and then immersed in 0.01 - 3 M K2S solution to prepare sulfur-immersed materials. The immersed-materials were heated at 100-700 ºC in nitrogen gas to produce the sulfur-impregnated carbonaceous adsorbent by pyrolysis. The contents of carbon and sulfur in the adsorbent and abilities of adsorbent to recovery nickel from aqueous solution were examined. The contents of carbon and sulfur in sulfur-immersed materials are almost same as those in raw material. In pyrolysis, with increasing the heating temperature to 200 ºC, the contents of carbon and sulfur are almost constant, and then above 300 ºC those increase. The recovery for nickel using raw material, sulfur-immersed material and the product pyrolyzed at 100 - 200 ºC are almost same, and with increasing the heating temperature to 400 ºC, that of the product increases, and above 500 ºC that of the product decreases. In immerse step, with increasing K2S concentration, the carbon content of the product at 400 ºC gradually decreases, the sulfur content of the product increases, and the recovery for nickel using the product gradually increases and then above 1 M K2S decrease. The product prepared from material immersed in 1 M K2S solution at 400 ºC indicates a maximum recovery for nickel ion. The product can adsorb nickel ion in nickel plating waste solution coexisting with phosphate ion, and adsorbed nickel ion in the product was deposited as nickel metal after heating at 1000 ºC under N2 atmosphere.INTRODUCTIONRice is the second world’s largest cereal crop after wheat, but produces large amount of straw residues, of about 330 million metric tonnes. Rice is a widely grown crop in Asia, and rice straw is produced as a by-product of rice production. In most parts of rice fields, open-field burning of rice straw is commonly practiced in the region when there is limited time to prepare a field for the next crop. However, open-field burning of crop residues is an uncontrolled combustion process during which air pollutants are emitted into atmosphere. These air pollutants have significant toxicological properties and are potential carcinogens (Gadede et al., 2009). Although wildfires are prohibited in cultivation fields of most countries, farmers usually keep on burning their crop by-products. Biomass burning is an important source of aerosol particles which may affect local and regional air quality (Gao et al., 2011), and also contribute to global climate changes."

Jan 1, 2016

By Myron W. Mellor

Much has been published concerning the subject of coal preparation as related to electric power generation however it is always a most vital topic for both utilities and coal producers, It also constitutes a field of study that is never finished since new concepts and changing demands continually require altered perspectives. One graphic illustration that has been used to emphasize the rapidity with which times are changing is the fact that during World War I, a station that consumed 1000 tons per day was looked upon as a large central station, while today some single generators require 1500 tons during the same period, For further emphasis, at that time a 20,000 horsepower turbo-generator was a mighty large machine; today, a unit of this size is planned for driving the boiler water feed pump required for a single large main unit. During the past ten years alone, electric utilities have more than doubled their percentage of coal consumed as compared to the total market. They now account for approximately 40% of the United States consumption and one-third of all production including export, Conversely, approximately 70% of all U. S. steam electric generation is by coal and this percentage is expected to increase. It is further predicted that utility consumption will increase from the current 160,000,000 tons per year to between 400 and 500 million tons in 1975 which is approximately equal to todays total production

Jan 1, 1959

By G. A. Knox

Mr. Chairman and Gentlemen: The subject assigned to me would cover a great many pages if it were gone into thoroughly. Therefore. I have just touched on a few of the most important points. I think that everyone engaged in the production of commercial coal understands all about its preparation, but I will set forth my views as to how I believe it is best accomplished. In order to produce the best prepared coal, your first attention should be to the miner at the working face. The most careful system of blasting should be adopted to avoid heavy charging of holes which results in the shattering of the coal. The lump, or any other screened sizes that may be screened from coal that has been improperly shot, are subject to greater degradation in transportation and handling, as well as reducing screened sizes, which results in dissatisfied customers in the first case, and lower realization in the latter.

Jan 1, 1928

By Fuqiang Zheng, Shuai Wang, Feng Chen, Yufeng Guo, Guanzhou Qiu, Tao Jiang

"The direct reduced iron powder and Ti-V-rich material was prepared from vanadium titanomagnetite concentrate by solid-state reduction-magnetic separation. The result indicated that under the studied conditions, adding KS can effectively improve the metallization rate of pellets. 2% KS was well mixed with vanadium titanomagnetite concentrate to make the pellets. The green pellet was preheated at 900 ? for 6 min. The preheated pellet was reduced at 1050 ? for 100 min, then crushed and ground to more than 80% was below 0.045 mm. The direct reduced iron powder and Ti-V-rich material were separated from the slurry by wet magnetic separation at 800Gs. The TFe content of magnetic material was 90.63%, and the Fe recovery rate reached 96.53%. The TiO2 and V2O5 contents of Ti-V-rich material were 28.40 % and 1.64 %, respectively. The TiO2 and V2O5 recovery rates were 69.05% and 96.82%, respectively. 1. Introduction The ilmenite and rutile are the main titanium resources which can be used in the present technical level and economic conditions[1,2]. However, with the rapid development of China’s economy, the market demand of titanium products is increasing sharply. The current supply of ilmenite and rutile cannot meet the needs of chemical industry[3]. China is rich in vanadium titanomagnetite concentrate which contains abundant titanium and vanadium resources. The TiO2 and V2O5 content of vanadium titanomagnetite concentrate are usually about 7% and 0.3%, respectively[4]. Because the TiO2 and V2O5 grades are low, it generally requires pre-concentrated to Ti-V-rich material before extracting the titanium and vanadium. Therefore, it is vital to find effective processes for pre-concentrating the titanium and vanadium in vanadium titanomagnetite concentrate. There are many methods[5-13] developed or under development to pre-concentrate Ti-V-rich material from vanadium titanomagnetite concentrate, including the blast furnace process, pre-reduction electric furnace process, to utilized vanadium titanomagnetite concentrate are direct reduction-electric furnace smelting, sodium salt roasting-direct reduction-electric furnace smelting and direct reduction-magnetic separation and so on. The blast furnace process and other methods cannot effectively utilize the titanium and vanadium resource due to the technical or environmental problems[9]. In this study, the vanadium titanomagnetite concentrate was obtained from Panxi region of China, the reserves of which account for 11.6% of vanadium and 35.17% of titanium all over the world[3]. The preparation of direct reduced iron powder and Ti-V-rich material based on reduction-magnetic separation is proposed. The process utilizes a new catalyst for titanium ore reduction in rotary kiln followed by magnetic separation. Using this novel technology, the titanium-vanadium and iron are successfully separated. Compared to the traditional reduction of Ti-bearing ore, the reduction temperature reduced to 1050 ?, leading to higher efficiency, lower energy consumption and investment, and broader applications."

Jan 1, 2018

By Johan Sundström

Anhydrous DyC13 was prepared by dehydration of DyCl3?6H20 in a fluidized bed using both batch- wise and continuous feeding. A gas mixture with varied composition of argon and HCl was used. The productivity was high, reaching values of 0.25 mol H20/m2-st during the reaction step 6- 1 and 0.062 mol H2O/m2.s during the reaction step 1-0. The product was free from hydrolytic compounds, such as DyOCI, if control of inlet gas composition versus temperature was achieved. From the results of various experiments, some relations between HCI-concentration and temperature in order to avoid hydrolysis have been deduced. The fluidization process efficiency decreases drastically after the dehydration has proceeded down to about 10 mol% of remaining water. Therefore, in a final treatment the last traces of water were removed by slowly purging gas through a packed bed. The water content could thereby be reduced to less than 1 mol%.

Jan 1, 1997

There are a number of methodologies which can be used for the preparation of environ- mental impact statements. Selection of a method depends upon the type of project and the environmental characteristics of the area where it is to be built. Most methods are satisfactory for assessing impacts on the physical environment but less so for the biological. Major problems may arise in deal ing with sociological issues because value judgements are involved. Several methods of approaching problems of this nature have been tried with some limited success.

Jan 1, 1976

By R. L. Kloberdanz

Peruvian legislation requires the preparation of an Environmental Impact Study (EIS) for new and expanding mines/beneficiation facilities and the preparation and implementation of an Environmental Adjustment and Management Program (PAMA) to control and mitigate environmental impacts associated with existing mining/beneficiation activities. Shepherd Miller, Inc., developed guidance documents for preparing an EIS and PAMA for Peru's Ministry of Energy and Mines and presented workshops to Peru's mining industry on preparing an EIS and PAMA. This paper discusses the process and approach taken and the results.

Jan 1, 1998

By Jerry M. Whiting, Landy A. Stinnett

The subject of this paper is broad and complex. Secondly, it is near and dear to the authors' hearts. Therefore, it doesn't seem possible to deal with every aspect of it in less space than a good size textbook. Also, if we dealt with all of the basics of feasibility studies and report preparation, we would cover a lot of material available in the literature, and would have to minimize our editorial comments. In view of these limiting realities, we have chosen to discuss selected facets of the subject, and to provide several comments which stem from our personal experiences during the past 20 years. "Think Ahead" hen someone is undergoing training to command a large ship, the following short phrase is engraved in his memory: "Think Ahead." The reason is simple enough. A battleship, aircraft carrier or oil tanker cannot change directions quickly, and if one waits to a what the other ship is going to do, there may be twisted metal and bodies scattered all over the ocean floor. The commanding officer has to use radar, forward rind aft lookouts, experience, common sense, intuition, weather forecasts, and everything else available to him to avoid trouble. Remember the USS Stark, and the fate of its captain? The fact the Stark was hit by a "friendly" missile didn't lessen the damage. How about running into a mine? Is it an excuse that no one thought about the possibility of a minefield ahead of the ship? The point is, relative to feasibility studies, that its prospective authors, and especially the commander of the efforts required to create it, must "think ahead" from the moment of their association with 4 mining activity. They must

Jan 1, 1987