01 Solid fuels (sources, winning, properties)

01 SOLID FUELS

Sources, winning, properties

00102246 Blasting agents and initiation systems Fiscor, S. Coal Age, 105, (I), 3-6. Many professionals in mining historically referred to discipline of production blasting as an art form. Shedding that image, the blasters at mines and quarries and the companies that develop blasting agents and initiation systems have turned to more engineering and science techniques to improve the blasting programme.

00102252 Coal recovery from Coal fines cleaning wastes by agglomeration with vegetable oils: effects of oil type and concentration Alonso, M. I. e/ crl. Fuel, 1999, 78, (7), 753-759. The aim of this work was to obtain high calorific value products from coal fines cleaning wastes by agglomeration with vegetable oils. These residues are mainly being disposed of in dumps, causing important economic and environmental problems. Three Spanish coal fines wastes from different coal cleaning plants were agglomerated with crude and refined sunflower and soybean oils over a wide range of oil concentrations. The response of these fines wastes to agglomeration with the oils was evaluated by the percentages of coal matter recovery, ash rejection and efficiency index. Speaking in terms of products quality, the best results were attained at the lowest oil concentrations, especially when the refined ones were used. In these cases, the agglomeration with vegetable oils allowed the recovery from coal fines wastes of a ready-to-burn fine coal fuel.

00/02253 00/02247 Carbon dioxide from coal combustion: variation with

Coalbed and coal mine methane in the Illinois basin: occurrence, composition, origin, and current activities

rank of US coal Quick, J. C. and Glick, D. C. Fuel, 2000, 79, (7). 803-812.

Damberger, H. H. and Demir, I. fiePr-. Symp.-Am. Chem. Sot., Div. Fuel

Carbon dioxide from combustion of US coal systematically varies with Cbem., 1999, 44, (I), 56-60.

ASTM (Standard classification of coals by rank, ASTM D 38890. American 1 he composition, occurrence, origin and current activities in coal-bed and coal mine methane found in the Illinois basin are reviewed.

Society for Testing and Materials, West Conshohocken, PA. 1990; 05.05: 193) rank indices, allowing the amount of COz produced per net unit of energy to be predicted for mdividual coals. No single prediciive equation is applicable to all coals. Accordingly, one equation is provided for coals above high volatile bituminous rank and another for lower rank coals. When applied to public data for commercial coals from western US mines these equations show a 15% variation of kg CO2 (net GJ) ‘. This range of variation suggests reduction of US COz emissions is possible by prudent selection of coal for combustion. Maceral and mineral content are shown to slightly affect COz emissions from US coal. It is also suggested that CO2 emissions increased between 6 and 8% in instances where Midwestern US power plants stopped burning local, high-sulfur bituminous coal and started burning low-sulfur, sub-bituminous carbon rank coal from the western US.

00/02254 Control of hydraulic fracturing of rocks for degassing of coal seams Voitenko, Y. I. Ekorekhnol. Resursoshere-~lenie, 1999, I, 33-36. (In Russian) This paper proposes ways reduce power-consuming hydraulic fracturing of rocks. The effective methods and technique to decrease the limit pressure of rupture are offered. Some of the ideas are already in use in oil and gas technologies.

00102255 Development of emittance of coal particles during devolatilization and burnoff

00102246 Characteristics of genesis of coal-bearing formations in the southwest part of Lvov-Volyn basin, Ukraine Shulga, V. F. Ceol. Zh., 1997, l-2, 29-34. On the base of actual material a description of the peculiarities of the formation of lower carboniferous coal-bearing subformation of the south- western part of Lvov-Volyn basin, Ukraine. The necessity of further exploration works is underlined for discovering new coal fields in upper coal-bearing sub-formation and for deciding the problems of generation of the basin coal-bearing formation.

00/02249 Characteristics of telemagmatic metamorphism of the Ceshui Formation coal in Lianyuan coal basin Bi, H. and Peng, G. Chin. J. Geochem., 1998, 17, (4), 379-384. The Ceshui Formation coal is mostly composed of anthracite, its metamorphism however, is less well documented. The systematic analysis of the reflectance of vitrinite and the results of X-ray diffraction of the Ceshui formation coal in the Lianyuan coal basin, the spatial variation characteristics of coal ranks, the extension of coal metamorphic belts, coal chemical structure and the effect on the degree of metamorphism of heat- production buried depth of the Indonesian-Yenshanian granites at the margins of the Lianyuan coal basin are discussed. The research results indicate that the telemagmatic metamorphism is the main factor leading to the metamorphism of the Ceshui Formation coal in the region investigated.

00102250 Closed porosity in fossil coals Alexeev, A. D. et 01. Fuel, 1999, 78, (6) 6355638. The focus of this report is on the presence of closed porosity in fossil coals. The development of a technique used to define closed porosity is shown. Volumes of closed pores for coals of the various types are detected experimentally. It is established that the contribution of closed pores in total porosity in most cases is greater than 60%.

00/02251 Coal quality and coal utilization in the twenty-first century Finkelman, R. B. and Gluskoter, H. Prepr. Symp.-Am. Chrm. Sot.. Div. Fuel Chem., 1999, 44, (I), 47-50. This review focuses on the worldwide utilization of coal in 21st century. Concerns about the effects on human health, plus local, regional and global environment influence it however. Reliable coal quality data can help decision-makers to make a better judgement of the risks and limit the possible environmental degradation and impact on health. Although millions of coal analyses have been performed worldwide, existing national coal quality databases are generally of limited use because majority of the data are not readily accessible. The USA Geological Survey is collaborating with agencies from other coal producing countries to create an integrated, electronic, worldwide coal quality database. The database on coals currently being burned, includes results of proximate and ultimate analyses; sulfur form data; concentrations of trace elements and modes of occurrence of elements that are important to the environment.

Bhattacharya, S. P. and Wall, T. F. Fuel, 1999, 78, (5), 511-519. During combustion and gasification a knowledge of the spectral emittance of coal particles is necessary for the measurement of particle temperature, devolatilization rate, rate of particle heat up, and power radiated by the particle. However, information on the development of emittance of coal particles which are devolatilized and burnt, as well as information on the emittance of char as a function of ash content is rare. This article examines the evolution of spectral emittance of coal particles as they are devolatilized. Two different coal samples were used. Spectral emission measurements were carried out on opaque layers of coal particles at wavelengths between 2 and 12 pm, and progressively at temperatures from 200°C to 1000°C to illustrate the effects of particle size and coal type on emittance, and more importantly the development of emittance with devolatilization. From one coal, char samples were generated in a drop tube furnace at three different burnout levels. Spectral emission measure- ments were carried out on opaque layers of these char particles to illustrate the effects of burnout and ash levels on emittance. Such measurements covering a wide range of temperature and wavelength are one of the very few reported in literature. The magnitude of potential errors of temperature measurement in pyrometry are expounded through a discus- sion of the implications of these results.

00102256 Distribution of trace elements in selected pulverized coals as a function of particle size and density Senior, C. L. Fuel Processing Technology, 2000, 63, (2-3), 2 15-241. Trace elements in coal have diverse modes of occurrence that will greatly influence their behaviour in many coal utilization processes. Mode of occurrence is important in determining the partitioning during coal cleaning by conventional processes, the susceptibility to oxidation upon exposure to air, as well as the changes in physical properties upon heating. In this study, three complementary methods were used to determine the concentrations and chemical states of trace elements in pulverized samples of four US coals: Pittsburgh, Illinois No. 6, Elkhorn and Hazard and Wyodak coals. Neutron Activation Analysis (NAA) was used to measure the absolute concentration of elements in the parent coals and in the size- and density-fractionated samples. Chemical leaching and X-ray absorption fine structure (XAFS) spectroscopy were used to provide information on the form of occurrence of an element in the parent coals. The composition differences between size-segregated coal samples of different density mainly reflect the large density difference between minerals, especially pyrite and the organic portion of the coal. The heavy density fractions are therefore enriched in pyrite and the elements associated with pyrite, as also shown by the leaching and XAFS methods. Nearly all the As is associated with pyrite in the three bituminous coals studied. The sub-bituminous coal has a very low content of pyrite and arsenic; in this coal arsenic appears to be primarily organically associated. Selenium is mainly associated with pyrite in the bituminous coal samples. In two bituminous coal samples, zinc is mostly in the form of ZnS or associated with pyrite, whereas it appears to be associated with other minerals in the other two coals. Zinc is also the only trace element studied that is significantly more concentrated in the smaller (45 to 63 pm) coal particles.

258 Fuel and Energy Abstracts September 2000