Composition, Properties and Using Fields of Product of Phosphogypsum Recycling

Nowadays about 200 million tons of phosphogypsum (PG) have been stored in the dumps of the chemical industry and non–ferrous metallurgy of Russia which pollutes the environment. This waste contains up to 98 % of two–water gypsum and impurities including rare earth metals (REM) in an amount of up to 0.5 % preventing its use in the production of building materials. A complex technology of FG recycling including extraction of REM, neutralization and dehydration of the pulp for using in the production of gypsum binders and Portland cement. Results of determination of density, grain, chemical and mineral compositions and structure of the product of recycling of FG of the “Sredneuralsky copper smelting plant” are presented. After the REM extraction, the PG is a loose lumpy mass with moisture content of 28–32 % which contains about 10 % of particles larger than 40 mm and not more than 60 % of particles less than 10 mm, it has a true density of 2.26 g/cm3, pH of aqueous extract is 5.95. It has the following chemical composition, mass. %: 0.87 SiО2; 0.93 A12O3; 0.20 Fe2O3; 31.00 CaO; 0.034 MgO; 44.27 SО3; 0.10 K2О; 0.42 Nа2О; 0.45 Р2О5(general); 20.73 of mass loss of ignition. The mineral composition of the PG processing product is represented by two-water gypsum and a slight amount of quartz. The possibility of using gypsum–containing waste in the production of gypsum binders and cement is considered. The effect of temperature and duration of firing, the dispersion, the type and quantity of chemical and mineral admixtures on physical and mechanical properties of gypsum binder, the influence of the type and amount of mineral additive on pelletizing and physic–mechanical properties of the granulated and pressed PG and its effects on setting time and strength of Portland cement are represented. It is recommended to use PG to obtain low–temperature and composite gypsum binders, regulation of Portland cement setting after extraction of REM. Keywords: phosphogypsum, recycling, composition, properties, technology, gypsum binder, Portland cemen

The Use of Reftinskaya State District Power Plant Fly Ash in the Production of Building Materials and Products

The system of dry ash–slag removal at the Reftinskaya state district power plant which provides capture, storage and shipment of fly ash to the consumers is considered in this study. The results of determination of chemical and phase composition, physical properties, melting temperature and activity of natural radionuclides of ash which is form during burning of stone coal of Ekibastuz basin are presented. Ash is acidic, superfine and refractory one with a low content of combustible substance. As to composition and properties it satisfies the requirements of Russian Standard no. 25818 and ships to consumers under Technical Conditions 5717–004–79935691–2009. The results of laboratory tests and industrial production of building materials and products on the basis of ash of Reftinskaya state district power plant are presented. It is shown that ash is used in the production of Portland cement, heavy and cellular autoclave concrete, dry mixes and can also be used as part of fly ash non-fired and agloporite gravel, ceramic bricks. The features of their production, basic physical and mechanical properties of building materials and products are described. It is shown that the introduction of a new system of dry ash removal at the state district power plant contributes to the expansion of directions and increase in the volume of ash recycling. Keywords: Reftinskaya state district power plant, dry ash removal, fly ash, composition, properties, use, construction materials and product

Granite Dust is the Possible Component of the Dry Construction Mixtures

This paper is devoted to research of possibility of utilization of granite dust. It is shownthat the granite dust from the crushing screenings of "Shartashskiy stone-crushed stone quarry" can be recommended as a filler for the production of dry building mixes for flooring. With the introduction of dust in the amount of 20 % by weight of cement it is possible to obtain the mortar of the class not less B12.5. Keywords: Granite dust, dust-like waste, Portland cement, polymer, modification, compressive strength, flexural strength, sand, dry mixture, mortar, compositio

The Composition and Properties of the Tailings of Quartzite Enrichment of “Gora Karaul’naya” Deposit

The JSC “DINUR” use enriched quartzite from the “Gora Karaul’naya” deposit in the production of dinas refractories. The tailings of quartzite enrichment are stored in the dump, not used, and thereby pollute the environment. Chemical, mineral and grain composition, physical, mechanical and technological properties of samples of quartzite tailings of the current output and selected from the dump are determined in this study. The tailings of current output contain less oxides of aluminum, iron and calcium and alkalis compared to the dump tailings. Their mineral composition is mainly represented by quartz as well as impurities of muscovite, hematite, magnetite, chlorite, shungite, zircon, rutile, pyrite with a total content of up to 3 %. The dump quartzite tailings contain particles less than 5 mm in size with a predominance of dust–like fractions (less than 0.16 mm). As to the grain composition, content of dust and clay particles, clay lumps and impurities tailings of the current output meets the requirements of Russian Standard no. 31424 (for the sand from sifting of crushing solid stone), belong to the class II, group of large sands; dump tailings belong to class I and the group of medium sands. Up to 30 % of the particles are plate– and needle–shaped. The features of changes in chemical composition, bulk density, content of dust–like, clay and organic impurities depending on the size of tailings fractions are considered. The possibility of using of tailings of quartzite enrichment as sand for construction works and fine fractions of tailings as molding material in foundry and granular loading in pressure and non−pressure filters for water purification is shown. Keywords: quartz, tailings, composition, properties, us

METHOD OF SOLID FUEL BURNING AT THERMAL POWER PLANTS

FIELD: technological processes; chemistry. SUBSTANCE: method includes preparation of fuel for burning, its burning, dry catching of ashes, moistening of ashes, its granulation, hardening of granules and their dispatch for recycling or storage, in which fuel is dosed prior to burning, and mineral additive is introduced, crushing of which is carried out together with fuel or separately, and for moistening of ashes during its granulation water or water alkaline solution are used, for instance, sodium carbonate or sulfate, with content of alkaline compound of 5-10% from ashes mass. EFFECT: application of invention allows to prepare multipurpose solid granulated product suitable for recycling and stockpiling. 3 cl.Изобретение относится к технологиям сжигания твердого топлива на ТЭС и касается объектов, сжигающих твердое топливо с кислым составом золы. Техническим результатом изобретения является разработка способа сжигания твердого топлива на ТЭС. Способ включает подготовку топлива к сжиганию, его сжигание, сухое улавливание золы, увлажнение золы, ее грануляцию, твердение гранул и их отгрузку на утилизацию или хранение, в котором топливо перед сжиганием дозируют и вводят минеральную добавку, измельчение которой осуществляют совместно с топливом или раздельно, а для увлажнения золы при ее грануляции используют воду или водный щелочной раствор, например карбонат или сульфат натрия, с содержанием щелочного соединения 5-10% от массы золы. Использование изобретения позволяет получать удобный для утилизации и складирования прочный гранулированный продукт многоцелевого назначения. 2 з.п. ф-лы, 3 табл

CHAMBER FEEDER OF DELIVERY PNEUMATIC TRANSPORT PLANT

FIELD: pneumotransport. SUBSTANCE: invention relates to discharge of loose materials, such as alumina, cement or other aggressive dust forming materials from flexible container by means of compressed air. Proposed chamber feeder has intake chamber with cover, discharge pipeline with intake branch pipe, and discharge nozzle with knife device. Flexible container is placed in intake chamber. Intake branch pipe is installed for free travel along discharge pipeline being furnished with knife device to cut upper part of flexible container. Discharge pipeline is furnished with intake branch pipe travel stop. Intake branch pipe installed for movement in discharge pipeline at aeration of material in process of delivery of compressed air through discharge nozzle into intake chamber provides its lowering to into material layer to close to discharge nozzle. Such free travel of intake branch pipe provides maximum capacity of chamber feeder. EFFECT: reduced power consumption for bringing material out of chamber feeder, increased reliability of its operation. 5 dwg.Изобретение относится к пневмотранспорту, а именно к выгрузке из гибкой оболочки (тары) сыпучих материалов, например глинозема, цемента и других агрессивных пылеобразующих материалов с помощью сжатого воздуха. Камерный питатель содержит приемную камеру с крышкой, разгрузочный трубопровод с заборным патрубком, нагнетательное сопло с ножевым устройством. Гибкая тара размещена в приемной камере. Заборный патрубок установлен с возможностью свободного перемещения вдоль разгрузочного трубопровода и снабжен ножевым устройством для разрезания верхней части гибкой тары. Разгрузочный трубопровод снабжен ограничителем движения в нем заборного патрубка. Подвижно установленный в разгрузочном трубопроводе заборный патрубок при аэрировании материала в процессе подачи сжатого воздуха через нагнетательное сопло в приемную камеру обеспечивает опускание его в слой материала до непосредственной близости к нагнетательному соплу. Такое свободное передвижение заборного патрубка обеспечивает максимальную производительность камерного питателя. Кроме того, изобретение обеспечивает уменьшение энергозатрат на вынос материала из камерного питателя и повышение надежности его работы. 5 ил

Quantum Spectral Curve at Work: From Small Spin to Strong Coupling in N=4 SYM

We apply the recently proposed quantum spectral curve technique to the study of twist operators in planar N=4 SYM theory. We focus on the small spin expansion of anomalous dimensions in the sl(2) sector and compute its first two orders exactly for any value of the 't Hooft coupling. At leading order in the spin S we reproduced Basso's slope function. The next term of order S^2 structurally resembles the Beisert-Eden-Staudacher dressing phase and takes into account wrapping contributions. This expansion contains rich information about the spectrum of local operators at strong coupling. In particular, we found a new coefficient in the strong coupling expansion of the Konishi operator dimension and confirmed several previously known terms. We also obtained several new orders of the strong coupling expansion of the BFKL pomeron intercept. As a by-product we formulated a prescription for the correct analytical continuation in S which opens a way for deriving the BFKL regime of twist two anomalous dimensions from AdS/CFT integrability.Comment: 53 pages, references added; v3: due to a typo in the coefficients C_2 and D_2 on page 29 we corrected the rational part of the strong coupling predictions in equations (1.5-6), (6.22-24), (6.27-30) and in Table