Ash Processing Research Articles

Fine fluorite nanoparticles synthesized from biomass ash

Fine fluorite (CaF2) nanoparticles were synthetised by reaction of ammonium fluoride with calcium carbonate phase obtained by processing of wood chips ash in sodium acetate trihydrate acting as transport medium and liquid environment at 120 °C on air. The synthesized nanoparticles were analysed by SEM-EDS, XRD, XPS and TEM measurements and nanocrystals of calcium fluoride with average size 12 nm were characterised in detail. The properties of the material as an anti-reflexive coating made from the synthesized nanoparticles were successfully tested. The suggested procedure represents a promising route of zero-waste technology of calcium-rich biomass ashes processing and may be utilised for production of large quantities of calcium fluoride nanoparticles.

Integrated Processing of Ash and Slag from Thermal Power Plants in Eastern Transbaikalia

The relevance of the studies into ash and slag from coal combustion in the thermal power sector in Eastern Transbaikalia is governed by the demand for highly efficient and environmentally clean processing technologies aimed at complete utilization of waste. The compositional analysis of the coal-fly ash—ash-and-slag geosystem is given. A special study of processability of ash and slag from combustion of Kharanor, Tataur amd Urtuy coals is carried out, and the main areas of their efficient use in the regional economy are substantiated. The process flow chart is developed for the integrated processing of ash-and-slag waste from thermal power plants in order to obtain marketable products in the form of xenospheres, magnetic fractions, rare and rare earth concentrates, as well as by-products for the building and road construction industries, etc. The proposed complete processing integrates principles of flotation, magnetic and electrostatic separation as well as leaching, and enables considerable reduction in the environmental impact, improvement in performance and increase in investment attractiveness of thermal power plants.

Resource-Saving Microsphere Technology for Friction Composite Materials

The paper proposes the miscrosphere electro-plasma technology based on the processing of bottom ash generated by the Belovo Power Plant, Kemerovo region, Russia. During the electro-plasma processing, the current-voltage characteristic of plasma flow is determined. It is shown that it considerably depends on the gas rate. For example, at 300 А arc current and the increase of gas rate from 1.0 to 2.0 g/s, the arc voltage grows from 130 to 180 V. The X-ray photoelectron spectroscopy allows obtaining the distribution maps for the elemental composition of the microsphere surface and detecting the element concentration. From the infrared spectroscopy, it is possible to conclude that the amorphized layer of obtained microspheres is characterized by an ordered structure, because 1093.82 сm-1 maximum position of the absorption band for stretching vibration is as close as possible to that for silica glass (1100 сm-1) representing a more ordered polymer structure.

Effect of Calcareous Fly-ash Processing Methods on Rheological Properties of Mortars

The paper presents the results of research into the influence of calcareous fly ash (CFA) processing methods on the rheological properties of mortars. The study consisted of a comparison of changes of the rheological properties (plastic viscosity and yield value) of the mortars during 90 minutes when CFA, unprocessed or processed by grinding, grain separation, or selective collection from the filter, was used as a substitute for a part of the cement. The results show that processing of CFA decreases its negative influence on the rheological properties; the efficient methods are separation or grinding, while the effect of selective collection is almost insignificant.

First experimental observations on melting and chemical modification of volcanic ash during lightning interaction

Electrification in volcanic ash plumes often leads to syn-eruptive lightning discharges. High temperatures in and around lightning plasma channels have the potential to chemically alter, re-melt, and possibly volatilize ash fragments in the eruption cloud. In this study, we experimentally simulate temperature conditions of volcanic lightning in the laboratory, and systematically investigate the effects of rapid melting on the morphology and chemical composition of ash. Samples of different size and composition are ejected towards an artificially generated electrical arc. Post-experiment ash morphologies include fully melted spheres, partially melted particles, agglomerates, and vesiculated particles. High-speed imaging reveals various processes occurring during the short lightning-ash interactions, such as particle melting and rounding, foaming, and explosive particle fragmentation. Chemical analyses of the flash-melted particles reveal considerable bulk loss of Cl, S, P and Na through thermal vaporization. Element distribution patterns suggest convection as a key process of element transport from the interior of the melt droplet to rim where volatiles are lost. Modeling the degree of sodium loss delivers maximum melt temperatures between 3290 and 3490 K. Our results imply that natural lighting strikes may be an important agent of syn-eruptive morphological and chemical processing of volcanic ash.

Synthesis of Zeolite A from Mongolian Coal Fly Ash by Hydrothermal Treatment

Raw coal fly ash and acid pretreated fly ash were used to synthesize A-type zeolite by hydrothermal treatment. In order to synthesize zeolite A an aqueous gel having a molar batch composition of Na2O:Al2O3:1.926SiO2:128H2O was utilized. Fly ash and zeolitic products were characterized by SEM, XRF, XRD and cation exchange capacity (CEC). After hydrothermal treatment, several types of zeolites were formed: zeolite A, analcime, faujasite and hydroxy-sodalite. The highest content of zeolite A was formed in the mixture treated at 80°C for 8 hours. CEC values of the zeolitic products were 28-38 times higher than that of in raw fly ash. Acid pretreatment which leads to low calcium and iron content is preferable method for processing of fly ash for the zeolite synthesis. Synthesized zeolite can be used for ion exchangers for water treatment.

ANALISIS KANDUNGAN BORAKS PADA BAKSO YANG DIJUAL DI ANDUONOHU KOTA KENDARI SULAWESI TENGGARA

Fast food consumption today has become a habit of eating for the people in Indonesia. One of the popular fast food is meatballs, but nowadays often found the use of non-food additives in the meatballs, namely borax. The Indonesian Republic Food and Drug Administration has detected the abusive use of borax on food derived from various regions of Indonesia. Borax is a chemical compound derived from heavy metals, namely Boron and commonly used as an anti-fungal and wood preservative. This study aimed to determine the content of borax on meatballs that was sold in Anduonohu, Kendari City of Southeast Sulawesi. Type of research using total sampling conducted by observational descriptive by the qualitative method that was using the method of centrifugation and dry ash processing. The results showed that from 24 samples of meatballs located in Anduonohu, Kendari City, it was proven that none of the meatballs contained borax which could endanger the consumer's health which was marked by no change of green color when heated on the flame. Based on the results of the analysis can be concluded that all sellers of meatballs located in Anduonohu, Kendari City have the knowledge and good attitude. Knowledge and attitude level is one important factor in order to avoid pollution of toxin material. Meatball processing method in Anduonohu, Kendari City has fulfilled the requirement of Indonesian Republic Health Minister Regulation in 2015, Number: 722/Menkes/Per /IX/2015 about food, so people do not have to worry about consuming meatballs located in Anduonohu, Kendari City.

Synergistic Thermal Processing of Dry Sludge Chaff and Incinerator Ash for Energy and Resource Recovery

Synergistic Thermal Processing of Dry Sludge Chaff and Incinerator Ash for Energy and Resource Recovery

Acidic processing of fly ash: chemical characterization, morphology, and immersion freezing.

Fly ash can undergo aging in the atmosphere through interactions with sulfuric acid and water. These reactions could result in chemical and physical changes that could affect the cloud condensation or ice nucleation activity of fly ash particles. To explore this process, different water and acid treated fly ash types were characterized with X-ray diffraction (XRD), transmission electron microscopy (TEM), electron dispersive spectroscopy (EDS), selected area diffraction (SAED), and inductively coupled plasma atomic emission spectroscopy (ICP-AES). Then, their immersion freezing activity was assessed. With water and acid treatment, a wide variety of metals were leached, depending on the starting composition of the fly ash. Acid treatment resulted in the formation of gypsum, Ca(SO4)·2H2O, for fly ash containing Ca as well as morphological changes. The immersion freezing activity was also assessed for each fly ash system to compare the effects of water and acid processing. Our results support the assertion that fly ash can serve as a cloud condensation or ice nucleus to affect climate.

Разработка и оценка качества хлеба с добавлением продукта переработки рябины амурской

Разработка и оценка качества хлеба с добавлением продукта переработки рябины амурской

ПЕРЕРАБОТКА ЗОЛОШЛАКОВЫХ ОТХОДОВ С ИЗВЛЕЧЕНИЕМ РЕДКИХ МЕТАЛЛОВ КАК КЛЮЧЕВОЙ ФАКТОР СОЦИАЛЬНО- ЭКОНОМИЧЕСКОГО И ЭКОЛОГИЧЕСКОГО БЛАГОПОЛУЧИЯ УГЛЕДОБЫВАЮЩИХ СТРАН

ПЕРЕРАБОТКА ЗОЛОШЛАКОВЫХ ОТХОДОВ С ИЗВЛЕЧЕНИЕМ РЕДКИХ МЕТАЛЛОВ КАК КЛЮЧЕВОЙ ФАКТОР СОЦИАЛЬНО- ЭКОНОМИЧЕСКОГО И ЭКОЛОГИЧЕСКОГО БЛАГОПОЛУЧИЯ УГЛЕДОБЫВАЮЩИХ СТРАН

Prospects and possibilities of using ash and slag wastes of power enterprises of Primorsky Krai as technogenic mineral raw materials

The results of an investigation of ash and slag wastes (ASW) of enterprises of the energy sector of Primorsky Krai are presented. The averaged contents of the main elements and mineral complexes in Primorsky Krai are given. It is shown that the mineral composition of the ASW data makes it possible to separate the primary raw materials into fractions with different compositions. A scheme is proposed for dividing the initial ash extractors into separate mineral fractions by the particle size and by their physical properties. The predominant concentration of gold, platinum, rare earth elements (REE) and a number of other valuable components in the heavy non-magnetic fraction isolated from the primary ASW was detected. Almost complete absence of gold, noble metals and REE in underburning of coal, magnetic and micro-dispersed fractions of ASW has been demonstrated. A device was offered for complex processing of ash and slag wastes of enterprises of the power industry of Primorsky Krai, which makes it possible to divide the initial ASW into mineral fractions, being raw materials for various industries.

Differences in the thermal behavior of beet and cane sucrose sources

Sucrose is a major worldwide commodity, produced mainly from sugarbeet and sugarcane. Despite the nearly identical chemical composition of these sugar sources, some differences in aroma and performance in products have been reported in the literature. However, little research exploring thermal behavior differences was found. By employing thermal analysis methods, this research reveals significant thermal behavior differences both between and within beet and cane sugars. Beet samples exhibited only one large endothermic DSC peak (Tmonset = 188.45 ± 0.43); whereas twenty-seven of the thirty-one cane samples exhibited two endothermic DSC peaks, one small peak (Tmonset = 153.62 ± 6.04) proceeded by one large peak (Tmonset = 187.33 ± 1.72). However, the four remaining cane samples, containing either high ash content or processing added impurities, exhibited only one large endothermic DSC peak. Understanding the thermal behavior differences between and within sucrose sources is of substantial importance to the food industry, especially in applications involving heat, such as baking, extrusion cooking, pasteurization, and drying.

Processing of ash and slag waste of heating plants by arc plasma to produce construction materials and nanomodifiers

The resultsare presented of plasma processing slag and ash waste from coal combustion in heating plants. Melting mechanism of ashand slagraw material is considered by an electromagnetic technological reactor. The analysis was conducted of temperature and phase transformations of raw material when it is heated up to the melting point, and also determination of specific energy consumption by using a generalized model of the thermodynamic analysis of TERRA. The study of materials melting temperature conditions and plum of melt was carried with high-temperature thermal imaging method, followed by mapping and 3D-modeling of the temperature fields. The investigations to establish the principal possibilities of using slag waste of local coal as raw material for the production of mineral (ash and slag) fibers found that by chemical composition there are oxides in the following ranges: 45-65% SiO2; 10-25% Al2O3; 10-45% CaO; 5-10% MgO; other minerals (less than 5%). Thus, these technological wastes are principally suitable for melts to produce mineral wool by the plasma method. An analysis of the results shows the melting point of ash and slag waste - 1800-2000 °C. In this case the specific energy consumption of these processes keeps within the limits of 1.1-1.3 kW*h/kg. For comparison it should be noted that the unit cost of electricity in the known high-melting industrial installations 5-6 kW*h/kg. Upon melting ash and slag waste, which contains up to 2-5% of unburned carbon, carbon nanomaterials were discovered.in the form of ultrafine soot accumulating as a plaque on the water-cooled surfaces in the gas cleaning chamber. The process of formation of soot consists in sublimation-desublimation of part of carbon which is in ash and slag, and graphite electrode. Thus, upon melting of ash and slag in the electromagnetic reactor it is possible to obtain melt, and in the subsequent mineral high quality fiber, which satisfies the requirements of normative documents, and simultaneously to receive a condensed product in the form of carbon sublimated nanoparticles, which can be found further use in construction materials, in particular in high-strength concrete and other materials.

Comparison of technological efficiency of gravitational devices for preparation of large diluted coal

The purpose of the work is to assess the possibility of preparation of poor washability, high-ash coals demonstrated by the example of the Apsat deposit. The following tasks have been accomplished. The analysis of modern equipment produced for washing of large classes of coal: heavy-medium separators and jigging machines. The most preferred were the heavy-media separator SKVP, jigging machines ROMJIG and BATAC. The analysis of mathematical models of processes and technologies of gravitational processing for determining the yield and ash content of the concentrate has been carried out. Algorithms and computer programs have been developed in which two mathematical models of the processes of heavy-media preparation and jigging machines have been used that allow determination of the separation densities at which the maximum yield of the total concentrate of the required ash content is reached. The computational experiment carried out showed that in processing of high ash diluted coals with poor washability, it is expedient to use SKVP separator and a jigging machine ROMJIG.

Chemometric analysis of alternations in coal ash quality induced by application of different mechano-chemical processing parameters

The coal fly ash mechano-chemical activation conducted via high energy ultra-centrifugal mill was optimized using mathematical and statistical tools. The aim of the investigation was to accent the merits of alternations in ash processing schemes with a referral regarding the enhancement of the ash reactivity that will lead to its higher volume utilization as a cement replacement in concrete design. The impact of the processing parameters sets (number of rotor revolutions, current intensity, activation period, circumferential rotor speed, mill capacity) on the on the product?s quality factors (grain size distribution, average grain size, micronization level, agglomeration tendency, specific surface area) was assessed via Response surface method, Standard score analysis and Principal component analysis in order to obtain the most favorable output. Developed models were able to meticulously predict quality parameters in an extensive range of processing parameters. The calculated r2 values were in the range of 0.846-0.999. The optimal ash sample, that reached the Standard Score as high as 0.93, was produced using a set of processing parameters appropriate to experimental sequence with applied 120 ?m sieve mesh. The microstructural characteristics were assessed using image-processing values and histogram plots of the activated fly ash SEM images.

Комплексная переработка золошлаковых отходов ТЭЦ гг.Хабаровск и Биробиджан

The results of laboratory and pilot tests for the integrated processing of ash and slag wastes of thermal power plants (TPP) are presented. The main attention is paid to the extraction of precious metals from wastes. Various metods of enrichment were tested. Principal technological schemes of complex waste processing with the extraction of valuable components have been developed

Thermochemical processing of a South African ultrafine coal fly ash using ammonium sulphate as extracting agent for aluminium extraction

South African coal fly ash represents an untapped secondary resource of aluminium. Continuous research is conducted to develop suitable chemical and/or geometallurgical processes for aluminium extraction, preferably accompanied by minimal silicon extraction. The thermochemical treatment of a South African ultrafine coal fly ash was investigated to test the feasibility of recovering aluminium using ammonium sulphate, a widely available, low-cost, recyclable chemical agent. The optimum processing conditions were determined to be a temperature of 500°C and a fly ash to ammonium sulphate weight ratio of 2:6 when a reaction time of 1h was used. Water leaching of the reaction product obtained under these conditions resulted in the selective recovery of 95.0% aluminium from the amorphous phase, with <0.6% Si extracted. Mullite was unlikely to have reacted with the extracting agent. Except for Si, the process was not element-selective, but the extraction of iron could be minimized by increasing the treatment temperature to 600°C without compromising Al extraction. Thermochemical treatment using ammonium sulphate may therefore represent a promising technology for extracting aluminium from coal fly ash, which could be subsequently converted to value-added products such as alumina.

Metal removal from Municipal Solid Waste Incineration fly ash: A comparison between chemical leaching and bioleaching

Bio- and hydrometallurgical experimental setups at 2-l reactor scale for the processing of fly ash from municipal waste incinerators were explored. We aimed to compare chemical H2SO4 leaching and bioleaching; the latter involved the use of H2SO4 and a mixed culture of acidophilic bacteria. The leaching yields of several elements, including some of those considered as critical (Mg, Co, Ce, Cr, Ga, Nb, Nd, Sb and Sm), are provided. At the end of the experiments, both leaching methods resulted in comparable yields for Mg and Zn (>90%), Al and Mn (>85%), Cr (∼65%), Ga (∼60%), and Ce (∼50%). Chemical leaching showed the best yields for Cu (95%), Fe (91%), and Ni (93%), whereas bioleaching was effective for Nd (76%), Pb (59%), and Co (55%). The two leaching methods generated solids of different quality with respect to the original material as we removed and significantly reduced the metals amounts, and enriched solutions where metals can be recovered for example as mixed salts for further treatment. Compared to chemical leaching the bioleaching halved the use of H2SO4, i.e., a part of agent costs, as a likely consequence of bio-produced acid and improved metal solubility.

Lignite ash: Waste material or potential resource - Investigation of metal recovery and utilization options

Ashes from lignite combustion for power generation contain strategic metals, metalloids and rare earth elements (REE) and may thus be a potential source of industrially demanded metals. The presented project focused on the assessment and utilization of this potential raw material. Lignite ash assessment showed that the largest ash amounts for a potential utilization in Germany are available in the Lusatia region and that these ashes have a high value potential. A stabilized ash taken from the landscape building “Spreyer Höhe”, Lusatia, served as the main sample. For enrichment, separation and mobilization of valuable substances from the lignite ashes mechanical and thermal pre-treatment methods as well as chemical and biological leaching approaches were applied. Mechanical ash pre-treatment provided enriched fractions by different methods but still suffered from low yields of enriched fractions. Thermal ash processing showed multiple significant phase changes compared to original ash. Digestion with sc-CO2 and chemical leaching using HClaq of untreated and thermally treated ash provided high extraction for the metals Al, Ca, Fe, Mg, with the highest values achieved for thermally treated ash. Alternatively, bioleaching was applied using acidophilic Fe/S-metabolizing microorganisms (MO) as well as heterotrophic MO. The results indicated likewise high and partly specific metal mobilizations, e.g. for the elements Al, Ca, Fe, Mg, Mn, V, Zn, Zr and for some REE. A potential utilization was investigated for the original stabilized ash (not treated otherwise) as well as for ash fractions and leaching residues. Two potential utilization routes were identified i) partial substitution of the original resource by original stabilized ash or ash fractions in the production of Al-Fe-solutions applicable for water treatment and ii) usage of original stabilized ash or residues from ash leaching as (reactive) supplement in cement, concrete and mortar production.