Nature protection technologies

3.3. Ash and slag properties

Part 3. ASH AND SLAG HANDLING

3.3. Ash and slag properties

3.3.1. Properties of coal ash in Russia

Irina Putilova, Viacheslav Putilov, .MPEI (TU)

In the paper data on the basic coal ranks burnt at the Russian TTPs, boiler types, chemical and mineralogical composition of the produced ash and slag and volumes of their formation are resulted. The data on ash and slag landfilling and their beneficial use in various branches of economy: road construction, manufacture of concrete and cement are presented. In Russia about 85 % of ash and slag from TPPs are transported by hydraulic ash removal systems, and only about 15 % are disposed using pneumatic ash removal systems. However, a transfer from "wet" to "dry" ash and slag conveying systems for the purpose of using these products in a dry condition, is now planned. In the paper the Russian standard GOST 25818-91 on ash in concrete is resulted, and also the comparative analysis of GOST and the European standard EN 450 is made. The example of quality management of ash at the arrangement of the staged combustion system at pulverized coal combustion (PCC) boilers is also considered. In the paper technologies applied for using ash and slag from TPPs are reflected: pilot installations for brick manufacture from ash and slag, installations for ash and slag benefication.

Part 3. ASH AND SLAG HANDLING

3.3. Ash and slag properties

3.3.2. Assessment of the degree of tpp ash-and-slag waste hazard for environment and human health

E.P. Dik, A.N. Soboleva, OAO «VTI»

The mineral part of coals with acid ash is approaching in its composition to the sedimentary rocks of Earth crust, which create the habitat for flora and fauna. Therefore the ash-and-slag waste after combustion of such coals must not be very hazardous both for environment and human health. It was established that the insignificant excess of potentially dangerous small elements in comparison with their content in sedimentary rock will not place in the TPP ash and slag in the category more hazardous for environment than in sedimentary rocks. Therefore the overwhelming majority of such ash and slag relates to the 5th class, i.e. to the practically safe waste.

The TPP ash-and-slag waste is classified abroad as not hazardous that is reflected in the main EU normative documents.

Part 3. ASH AND SLAG HANDLING

3.3. Ash and slag properties

 3.3.3. Hollow microspheres from Fly ashes of power plants

L.D. Danilin1, V.S. Drozhzhin1, M.D. Kuvaev1, N.V. Maximova1, I.V. Pikulin1, S.A. Redyushev1, M.Y. Shpirt2
Russian Federal Nuclear Center — All-Russian Research Institute of Experimental Physics, Sarov, Russia (1)
Institute of Combustible Resources — Science and Technology Center for Combined Processing of Solid Combustible Resources, Moscow, Russia (2)

 A progressive tendency in material-consuming branches of industry is transformation of industrial wastes into the raw materials appropriate for industrial implementation. It can be fully referred to the microspheres from fly ash that can be considered as a side industrial product from operation of electric power stations. In the period of time since 1996 till 2002 specialists from RFNC-VNIIEF carried out technical monitoring at the electric power stations in the Russian Federation related to microspheres from the fly ash. The main goal of the monitoring was analysis of microsphere formation processes at the ash dumps of the electric power stations and study of the basic consumer properties of microspheres. As a result, they accumulated a summarized large material arranged now in the form of a computer program called «Ash Microspheres of the Russian Federation. Database» Thanks to the favorable combination of technical and commercial parameters microspheres of fly ash can be used in creation of various functional materials, including filled composites on the basis of inorganic and organic binders.

Part 3. ASH AND SLAG HANDLING

3.3. Ash and slag properties

3.3.4. Biogeochemical characteristic of Fuel power engineering wastes by the example of urgalsk coal field

S.Е. Sirotskiy, Institute of water and ecological problems of FEB RAS, Khabarovsk, Russia

Biogeochemical characteristic of fuel power engineering wastes by the example of Urgalsk coal field is considered.

Part 3. ASH AND SLAG HANDLING

3.3. Ash and slag properties

3.2.3. Bottom ash/slag removal

3.3.5. Novel functional materials based on ferroaluminosilicate microspheres from fly ashes of power-generating coals

A. G. Anshits, N. N. Anshits, S. N. Vereshchagin, T. A. Vereshchagina, E. V. Rabchevskii, E. V. Fomenko, and O. M. Sharonova, Institute of Chemistry and Chemical Technology, Siberian Branch of the Russian Academy of Sciences, Krasnoyarsk, Russia

A systematic investigation of the relationship between the composition, structure, and physicochemical properties of narrow fractions of microspheres―ferrospheres and cenospheres separated from all known types of fly ashes of power-generating coals―has been performed for the first time.

It has been shown that microspheres separated from fly ashes of energy coals are promising for the use in the design of new functional materials: catalysts and diffusion membranes intended for the processing of the helium-bearing natural gas from the Eastern Siberia with the aim of producing ethylene and helium as target products, as well as sorbents for solidification of liquid radioactive wastes in the mineral-like form.

Part 3. ASH AND SLAG HANDLING

3.3. Ash and slag properties

3.3.6. The use of Kamika equipment for examination of distributions of particles in coal dust and ash, as well as for measurements of dust content in flue gases

D. Kamińska, S. Kamiński, KAMIKA Instruments, Warszawa, Poland

 Each process engineer in his struggle with precise definition of the grain-size distribution of the coal dust, ash, lime powder and synthetic gypsum, has to give some thought to the question, how much time need such measurements and how frequently he/she is able to repeat these measurements in order to control the process he/she operates e.g. coal combustion or flue gas desulfurization. Usually such measurements are made sporadically in relation to the bulk of material used in the process, trusting that the coal dust or lime powder have stable grain-size distribution, which assumption does not always agree with reality. Moreover the currently made measurements are always made too late. Examination results are obtained after the raw material has been applied and there is no possibility to make any grain-size corrections.

Part 3. ASH AND SLAG HANDLING

3.3. Ash and slag properties

3.3.7. Experience and regulatory framework for the use of dry fly ash from Russian TPPs for producing concrete, mortar and dry construction mixes

A.V. Ukhanov, ProfCement-Vektor, CJSC- the leader of Phoenix Consortium, Saint Petersburg, Russia

 Here you can find the studies of basic consumer properties of fly ash from domestic and foreign TPPs, as well as the main methods of fly ash application to produce concrete, building mortars and dry building mixes.

The analysis was made concerning the current state of the regulatory framework of the Russian Federation, touching upon subject of the use of TPP’s fly ash for production of concrete, building mortars and dry building mixes.

Part 3. ASH AND SLAG HANDLING

3.3. Ash and slag properties

3.3.8. The necessity and practicality of raising the quality and processing characteristics of ash and slag waste of thermal power plants for their successful use in production of cement and other construction materials

L.Y. Goldstein, ALITinform: Cement. Concrete. Dry Mixtures International Analytical Review, St. Petersburg, Russia

 The successful achievements in practical and efficient use of ash and slag waste from thermal power plants in a number of advanced foreign countries are well known and quite significant. The achievements of the Russian Federation in this respects are, on the contrary, extremely modest. Today, it has become obvious that no significant success can be achieved without the willed relevant decisions of supreme government bodies (legislative as well as executive) that would take into consideration the technical, economic, and processing features of the discussed problem.

At the same time, special attention should be paid to the necessity of improving the quality (consumer) and therefore marketable properties of the ash and slag materials. In such case, there probably will not be any more discussion about whether these materials are waste or by-products of thermal power plants.

 Part 3. ASH AND SLAG HANDLING

3.3. Ash and slag properties

3.3.9. Shape and grain size measurement of microspheres

D. Kamińska, S. Kamiński, KAMIKA Instruments, Warszawa, Poland

 In commonly adopted opto-electronic measuring methods each measured grain is compared to a sphere, independently of its actual shape, only having in mind the calculation simplicity. With such a method the grain-size characteristics of the given material is explicitly defined. In case when such results are compared with the mechanical sieving results, it is possible to make conclusions about the grain form, because the measurement of spherical particles should give similar results in both methods, while the larger are the differences in measurements, then the particles are more elongated or flattened.

Part 3. ASH AND SLAG HANDLING

3.3. Ash and slag properties

3.3.10. Investigation of influence of the particle shape and polydispersity on the critical velocities of dust and air flows while transporting the fine polydisperse materials in pneumatic conveying pipelines

I.V. Putilova, V.Y. Putilov, A.R. Khasyanshina, National Research University “Moscow Power Engineering Institute”, Russia

 The article provides brief results of analyzing the studies of various modes of pneumatic conveying of fine polydisperse bulk solids, presented in Russian and foreign sources of scientific and technical information. The following modes have been considered: plug flow, dilute- and dense-phase conveying with significantly different velocities of the flow, conveying of fine materials with particles of various sizes and geometric shape - from spherical to plate, sharp-cornered and even shell-acute. The results of analysis of pneumatic conveying technologies used in the energy sector of Russia and world-wide are described. The paper contains brief results of analyzing the research presented in scientific and technical information sources relating to definition of the shape and polydispersity of particles of fine polydisperse materials.

Part 3. ASH AND SLAG HANDLING

3.3. Ash and slag properties

3.3.11. Refinement of dependence for estimating critical velocities of dust and air flow considering the factors of shape and polydispersity of particles

I.V. Putilova, V.Y. Putilov, National Research University “Moscow Power Engineering Institute”, Russia

 The paper presents the results of experimental studies of the shape and polydispersity of particles of cyclonic oil shale, unclassified and classified ESP ash and classified cenospheres obtained from combustion of Kuznetsk coals at Belovskaya SDPP. The shape and polydispersity factors of particles of the studied bulk solids are developed.

The dependence for estimating critical velocity of dust and air flow at pneumatic conveying of fine polydisperse materials with regard to particle shape and polydispersity is verified.