07 Solid fuels (preparafion)

95/03308 Determination of changes in rheological properties of coal slurries In process streams Kawatra, S. K. and Bakshi, A. K. Coal Preparation, 1995, 15, (3), 165-175. A new technique involving a rotational (coaxial cylinder) viscometer and a vibrating sphere viscometer was developed for the rheological characteri- zation of coal slurrv orocess steams as either Newtonian or non- Newtonian. Both viscbm’eters were able to measure apparent viscosity as low as one centipoise, and special precautions were taken to allow mea- surement of rapidly settling coal suspensions. In this technique: the vibrat- ing sphere viscometer was used to measure the apparent viscosity at a high shear rate, while the rotational viscometer was used to measure the appar- ent viscosity at a low shear rate. Together, the two instruments could determine the shear-rate dependency of the viscosity, and thus provide an estimate of the total slurry rheology.

95103318 The influence of different chelators on the solubllization/liquefactlon of different pretreated and natural lignites Fakoussa, R. M. Fuel Process. Technol., 1994, 40, (Z), 183-192. Describes lignite solubilization in the presence of chelators. Also describes the effects of ash and oxygen content.

95103319 Inhibition of the swelling of coal from the Zoflowka coal mine using a solution of ammonlum chloride Dyrga, L. Arch. Min. Sci., 1994, 39, (3), 397-406.

95103320 Lignite and its beneflclation Tarjan, G. Banyasz, Kohasz. Lapok, Banyasz, 1994, 127, (2), 237-246. (In Hungarian) Discusses the properties of montmorillonite, its removal from lignite, power plant budgeting as a function of slag amount. 95103309 Development of environmental-friendly briquets for

Industrial firlng places Kleisa, K. et al., Glueckauf-Forschungsh., 1994, 55, (4), 117-122. (In German) Reports that DMT-Inst. Robstoffe Aufbereitung, Germany have developed an industrial fuel briquet consisting of approximately 87% bituminous coal. 7% molasses oulo. and 6% hvdrated lime. which meets the reauire- me& of the clean’ ai; ‘authorities ‘as an environmental friendly f&l for travelling-grate boilers. In extensive tests in a 4.4 MW travelling-grate boilers, the briquets with molasses and lime additives were especially effective in reducing SO, emissions in the flue gas.

95103321 Mechanical activation of coals Khrenkova, T. M. and Kird, V. S. Khim. Tverd. Topl. (Moscow), 1994, (7), 36-42. (In Russian) The paper discusses the effect of milling on coal properties and structure.

95103322 Method for determination of flotation activity of apolar reagents during flotation of coals Solov’eva, T. A. and Muklakova, A. N. Koks Khim., 1994, (lo), 40-42. (In Russian1 \.__ ..-___-__, Discusses the effectiveness of nonpolar reagents (kerosine, fuel oil, and

95103310 Dust suporesslon at an Impact crusher with hlah- dodecane) in coal flotation which is calculated based on flotation . ’ pressure water performance.

Henke, B. and Churic, N. Glueckauf; 1994, 130, (lo), 646-649. (In German) The use of high-pressure water and the efficiency of coal dust suppression was investigated on an SB 63 impact crusher in a dust suppression test facility during mining.

95103323 Method for reducing sulfate formation during regeneration of hot-gas desulfurization sorbents Bissett, L. A. et al., (Assigned to) US Deparrment of Energy, US Pat. .X%5,348,921, Sep. 1994.

95103311 An emulsified asphalt binder for coal brlquets Sha, X. ef al., (Assigned to) Wusong Coal Gas Plant, Faming Zhuauli Shenqing Gongkai Shuomingshu, CN.1,081,463, Feb. 1994. An emulsified asphalt binder is added into coal briquets at the rate of 2-7% alone or 2-5% plus 3-5% clay as a composite binder. The coal briquets have high mechanical strength, moisture resistance and thermal stability and less pollution, and are suitable for gasification.

95103312 Flocculation of coal suspensions Tobiczyk, A. and Ligocka, K. Przegl. Corn., 1994, 50, (9), 18-21. (In _ . . .\ ronsn) Describes the flocculation of coal suspensions of various ash content and particle size by using a set of flocculants. The best results were reported for flocculants of very large molecular weight (e.g. lo’), of both low and medium degree of hydrolysis, containing 20-50% negative charge func-

95103324 Microbial desulfurization of coal and oil Klein, J. et al., Fue/ Process. Technol., 1994, 40, (2), 297-310. The paper discusses biodesulphurization of coal and petroleum with emphasis on organic sulphur removal.

95103325 Microbial desulfurization of coal by chemoauto- trophic Thiobacillus ferrooxldans - An iron mine isolate Mannivannan, T. et al., J. Environ. Sci. Health, Part A, 1994, 29, (lo), 20452061. The authors describe how chemoautotrouhic Thiobacillus ferrooxidans. isolated from iron mine sludges, was u&d for desulphurization of coal: Effective desulphurization could be achieved at a constant pH of 2.2, with an overall low content of salts and in the presence of ferrous salts as rate accelerators.

tional groups. 95103326 Microbial desulfurlzation of coal bv Thlobacillus

95103313 The Galatia preparation plant expands throughout Reed, S. R. et al., Coal Msg., Apr. 1995, 100, (4), 58-60, 62. Discusses the new technology which has been added to the Galatia prepa- ration plant in Illinois, by Kerr-McGee.

95103314 Granulation of highly active coke briquets for blast furnace use Nakagaw, K. et al., (Assigned IO) Shinnippon Seitetsu KK, JAP. Pat. 06,299,177, Oct. 1994.

95103315 Gravity separation Brewis, T. Mining Msg., May 1995, 172, (5), 279-280, 283, 285. Discusses gravity separation which is one of the oldest mineral processing techniques yet, with modern developments, it is still to the fore.

95103316 Hydrophilic colloids and the elimination of lnor- ganlc sulfur from coal: A study employing contact angle measurements

ferrooxidans and thermophllic archaea Olsson, G. et al., Fuel Process Technol., 1994, 40, (2), 277-282. Coal biodesulphurization by Thiobacillus ferrooxidans and Aciedianus brierleyi is discussed. The rate constant for oxidation of pure pyrite by A. brierleyi was higher than that for T. ferrooxidans. The values of the rate constants for silphur removal from coal were comparable for the two microorganisms, but were higher than for oxidation of pure pyrite.

95103327 Microbial desulfurization of coal with Thiobecillus ferrooxidans bacteria Juszczak, A. et al., Fuel, May 1995, 74, (5), 725-728. Microbial desulphurization of Polish flame coal, characterized by high total concentration of sulphur and a high concentration of pyrite sulphur, was studied. The optimum conditions of the process were established.

95103328 Mixing it up. Coal blending in the ’90s Walz, M. A. er al., Coal Mag., Apr. 1995, 100, (4), 63-65. Discusses coal blending which has become important to the utility industry in this decade because of its flexibilitv and economic benefits. Coal blend- ing can maintain utility capacity whcle lowering emissions, reducing fuel costs and improving operations by reducing fouling and slagging.

Good, R. J. et al., Colloids Surf. A., 1994, 93, 39-48. The efficiency of selective oil agglomeration to remove inorganic sulphur from coal can be increasd by the addition of boiled starch. Starch that was not boiled had a barely detectable effect. Measurements of the effect of n- octanol on the oil-water-solid contact angle on coal and on the n-decane- water interfacial tension, were also made.

95/03317 Indexing the washability characteristics of Coal Govindarajan, B. and Rao, T. C. Inf. J. Miner. Process., 1994, 42, (3), 285-293. The washability data on coals of different origins were analyzed in terms of the relation between the cumulative weight fraction of feed material floated and the recovery of non-ash and ash material in the float fraction at a given specific gravity. A unique recovery curve existed in both the recov- eries of non-ash and ash material when plotted against the cumulative weight fraction of feed material floated.

95103329 On the activation of Asturian anthracite following various pretreatments Centeno, T. and Stoeckli, F. Carbon, 1994, 32, (S), 1463-1467. An Austrian anthracite was subjected to different pretreatments and subse- quently activated by steam at 850” to a total burn-off of 55%. The physical proper&s (micropore sizes and distributions, external surface areas, etc.) of the solids are compared with those of the carbon obtained by direct activation. Although the yield is generally low, it appears that better results are obtained by activation following preoxidation in air at 270” for 3 days. In the case of pretreatments with a mixture of N, air, and water vapour at 450”, the subsequent activation is less efficient. The micropore volumes and the pore sizd distributions are similar to those observed for soft precur- sors, but at a much lower degree of burn-off.

246 Fuel and Energy Abstracts July 1995