Complex Processing of Pulverized Fly Ash by Dry Separation Methods

Pulverized fly ash (PFA) is produced about 500 billions tons every year in the world in a result of coals combustion. Most of the fly ash collected in power plants is disposed by deposition in landfills, situated as a rule near big cities with well developed infrastructure and high cost of land. Moreover, the pollution of environmental by fine solid wastes is inevitable and takes place in area of residing of a basic part of the population. The only solution is a complex processing of fine wastes with a production of value added materials. New conception of complex processing of PFA is proposed on the base of facilities of Electro-mass-classifier (EMC) and other techniques. The characterization of separated fractions was carried out by SEM and optic microscopy, XRD, laser diffraction, M?ssbauer spectroscopy and other methods. A fine fraction of glass microspheres presents the main interest as filler in various materials.

Machine learning-driven optimization of plasma-catalytic dry reforming of methane

This study investigates the dry reformation of methane(DRM)over Ni/Al_(2)O_(3)catalysts in a dielectric barrier discharge(DBD)non-thermal plasma reactor.A novel hybrid machine learning(ML)model is developed to optimize the plasma-catalytic DRM reaction with limited experimental data.To address the non-linear and complex nature of the plasma-catalytic DRM process,the hybrid ML model integrates three well-established algorithms:regression trees,support vector regression,and artificial neural networks.A genetic algorithm(GA)is then used to optimize the hyperparameters of each algorithm within the hybrid ML model.The ML model achieved excellent agreement with the experimental data,demonstrating its efficacy in accurately predicting and optimizing the DRM process.The model was subsequently used to investigate the impact of various operating parameters on the plasma-catalytic DRM performance.We found that the optimal discharge power(20 W),CO_(2)/CH_(4)molar ratio(1.5),and Ni loading(7.8 wt%)resulted in the maximum energy yield at a total flow rate of∼51 mL/min.Furthermore,we investigated the relative significance of each operating parameter on the performance of the plasma-catalytic DRM process.The results show that the total flow rate had the greatest influence on the conversion,with a significance exceeding 35%for each output,while the Ni loading had the least impact on the overall reaction performance.This hybrid model demonstrates a remarkable ability to extract valuable insights from limited datasets,enabling the development and optimization of more efficient and selective plasma-catalytic chemical processes.

Application of single neuron adaptive PID controller during the process of timber drying

The paper presents a method of using single neuron adaptive PID control for adjusting system or servo system to implement timber drying process control, which combines the thought of parameter adaptive PID control and the character of neural network on exactly describing nonlinear and uncertainty dynamic process organically. The method implements functions of adaptive and self-learning by adjusting weighting parameters. Adaptive neural network can make some output trail given hoping value to decouple in static state. The simulation result indicates the validity, veracity and robustness of the method used in the timber drying process

Experimental study on shrinkage and rehydration of seed during drying process

Biomaterial will shrink during the drying process. The characteristics of shrinkage and rehydration of fresh peas were studied. Drying curves, shrinkage and rehydration curves of peas without seed coats and whole peas were compared. In addition, different volumetric shrinkage coefficients were obtained and discussed. The results show that seed coats resist moisture movement not only from inside to outside but also from outside to inside during different drying conditions. During a seed’s drying process, the drying curve is similar to the shrinkage curve. The higher the heat flux is, the less drying time is needed, and in the meantime, volume would shrink more and more intensively. Dried media will break easily at high heat flux. When we create a drying regime, both drying speed and the quality of dried media should be considered.

Early Hydration and Setting Process of Fly Ash-blended Cement Paste under Different Curing Temperatures

A specially developed ultrasonic measurement apparatus (UMA) was used to in situ monitor the setting process of fly ash blended cement paste. Combined with the results of Vicat Needle tests, isothermal calorimetric measurement, XRD analysis, SEM morphology and compressive test, the influence of curing temperature (20, 40, 60, and 90 ℃) and fly ash content (0,10%, 20% and 30%) on the setting and hydration process of fly ash blended cement paste was analyzed. The results show that setting and hardening process of fly ash blended cement paste at elevated temperature can be clearly identified into three stages including dormant stage, acceleration stage and deceleration stage. The increasing of curing temperature greatly accelerates the setting and hardening process. However, the content of fly ash does not have significant effect on the setting in condition of 90 ℃. Besides, the initial and final setting time of cement paste is correspondent with the time of duration of dormant stage and the time of UPV value is 1500 m/s (T1500), respectively. Thus, the UMA can be used to determine the initial and final setting time of cementitious material under different curing temperatures. The compressive test results indicate that the paste with 20% fly ash presents higher compressive strength than the plain paste at curing temperatures of 90 ℃. Therefore, appropriate amount of fly ash is beneficial for concrete in the high temperature curing conditions.

Influence of processing route on microstructure and wear resistance of fly ash reinforced AZ31 magnesium matrix composites

Utilizing fly ash(FA)as reinforcement for magnesium matrix composites(MMCs)brings down the production cost and the land pollution.Magnesium alloy AZ31 was reinforced with FA particles(10 vol.%)successfully by two different processing methods namely conventional stir casting and friction stir processing(FSP).The microstructural features were observed using optical microscope,scanning electron microscope and electron backscatter diffraction.The sliding wear behavior was tested using a pin-on-disc wear apparatus.The stir cast composite showed inhomogeneous particle dispersion and coarse grain structure.Some of the FA particles decomposed and reacted with the matrix alloy to produce undesirable compounds.Conversely,FSP composite showed superior particle dispersion and fine,equiaxed grains by dynamic recrystallization.FA particles encountered disintegration but there was no interfacial reaction.FSP composite demonstrated higher strengthening and wear resistance to that of stir cast composite.The morphology of the worn surface and the wear debris were studied in detail.

Development of volatiles and odor-active compounds in Chinese dry sausage at different stages of process and storage

The effect of process and storage on the volatiles and odorant profi le of Chinese dry sausage was evaluated,as well as its physicochemical parameters.Microbial esterification and wine(27.54%–43.35%),and lipid oxidation(11.30%–34.92%)played a key role in flavor profile during process and storage.A significant increase of each volatile was detected during process except gradual decrease of volatiles from spices,while a gradual decrease of each volatile was detected during storage except signifi cant increase of volatiles from lipid oxidation and esterifi cation.15 and 6 odor-active compounds were respectively correlated(P<0.05)with the process and storage time.Level of heptanal,1-octen-3-ol,the ethyl of 2-methylbutanoic,3-methylbutanoic,butanoic,benzoic,hexanoic,heptanoic,octanoic and decanoic acid were best discriminators of process stage,while(E)-2-nonenal,ethyl hexanoate,ethyl heptanoate,and methyl decanoate,were marker compounds of storage time.An objective method was established to evaluate the stages of process and storage for samples.

Second-order difference scheme for a nonlinear model of wood drying process

A numerical simulation for a model of wood drying process is considered. The model is given by a couple of nonlinear differential equations. One is a nonlinear parabolic equation and the other one is a nonlinear ordinary equation. A difference scheme is derived by the method of reduction of order. First, a new variable is introduced and the original problem is rewritten into a system of the first-order differential equations. Secondly, a difference scheme is constructed for the later problem. The solvability, stability and convergence of the difference scheme are proved by the energy method. The convergence order of the difference scheme is secondorder both in time and in space. A prior error estimate is put forward. The new variable is put aside to reduce the computational cost. A numerical example testifies the theoretical result.

Effect of Fly Ash on Drying Shrinkage of Thermal Insulation Mortar with Glazed Hollow Beads

Drying shrinkage of thermal insulation mortar with glazed hollow beads was measured by a vertical length comparator, and the influences of fly ash with different contents（0, 18%, 36%, and 54% were used） on the long-term drying shrinkage were discussed. The mass loss was measured by the weighting method and the pore structure was characterized using three different methods, including the light microscopy, the mercury intrusion porosimetry（MIP）, and the nitrogen adsorption/desorption（NAD） experiments, and the correlations among them were researched. The results show that drying shrinkage process of thermal insulation mortar includes three steps with increasing curing time： the acceleration period（before 7 d）, the deceleration period（7-365 d）, and the metastable period（after 365 d）. Drying shrinkage in the first stage（7 d before） increases quickly owing to the fast water loss, and its development in the last two stages is attributed to the increment of the pore volume of mortar with the radius below 50 nm, especially the increment of the pore volume fraction of the pore radius within the size range between 7.3 nm and 12.3 nm. There is no change in the drying shrinkage development trend of mortar with fly ash addition, and three steps in the service life, but fly ash addition in the mortar restrains its value. There is a linear relationship between the drying shrinkage and fly ash content, which means that drying shrinkage reduces with fly ash addition.

Simulation of Wetting and Drying Processes in A Depth Integrated Shallow Water Flow Model by Slot Method

A particular porosity method named ＂slot method＂ is implemented in a depth-integrated shallow water flow model （DIVAST） to simulate wetting and drying processes. Discussed is the relationship between the shape factors of the ＂slot＂ and the preset depth used in ＂wetting-drying＂ algorithm. Two typical tests are conducted to examine the performance of the method with the effect of the shape factors of the ＂slot＂ being checked in detail in the first test. Numerical results demonstrate that： 1 ） no additional effort to improve the finite difference scheme is needed to implement ＂slot method＂ in DIVAST, and 2） ＂slot method＂ will simulate wetting and diying processes correctly if the shape factors of the ＂slot＂ being selected properly.

Investigation and analysis of a fluidized bed dryer by process tomography sensor

In the pharmaceutical industry,fluidized beds are typically used for pellets drying,coating and granulation.The gas-solids flow characteristic in the process plays an important role to control the heat and mass transfer as well as the end-point product quality.Therefore,it is necessary to investigate the flow characteristics based on advanced measurement technologies.In this research,electrical capacitance tomography(ECT)sensor with eight electrodes was used to investigate the pharmaceutical fluidized bed drying process with different operation conditions.Key process parameters including solids concentration,particle moisture and capacitance signals in the process are given and analysed based on the ECT sensor.In addition,the fluidized bed process with Wurster tube is also investigated based on this ECT sensor.The effect of Wurster tube on the hydrodynamic behaviour and the dominant frequency spectrum distribution in the chamber were analysed based on fast Fourier transform.Test results reveal that process moisture change can be addressed from the raw capacitance of adjacent electrode pair combined with calibration model.Experimental result also indicates that ECT technology can provide useful information for process monitor in a fluidized bed dryer.

Application of Fly Ash and Organic Material as Dry Cover System in Prevention of Acid Mine Drainage Generation

The common practice in AMD prevention is a dry cover technique. In this technique, rock that is potential in producing acidity (PAF) will be placed below non-acid producing rock (NAF). Depends on NAF availability in the mine site situation, organic covers can be used to prevent diffusion of oxygen into reactive sulphide wastes and subsequently to eliminate sulphide compounds oxidation and generation of acidic waters. The utilization of additional material cover layer is proposed, by using fly ash and organic material combination. To investigate the possibility of using these materials, a column leaching test in the laboratory scale was conducted with several scenarios of simulation. By comparing between column with different thickness of fly ash and organic material, the leachate water behavior is observed in the experiment, including the measurement of water quality (pH and EC), major cations-anions. The result suggests the possible thickness of fly ash (FA) and organic material (OM) as cover layer material, especially in the case of mine with domination of PAF rock material.

Bacterial Cellulose-Silver Antibacterial Composites：Effects of Drying Processes of Bacterial Cellulose

A type of antibacterial bacterial cellulose(BC) film was prepared for potential uses as wound dressing.In order to obtain a high antibacterial effect,some forms of BC films,including the wet and dried ones were utilized as the template to in situ synthesize silver nanoparticles(AgNPs).The effects of drying methods including freeze-drying,heat drying and air drying,on the microstructures and physical properties of BC,as well as the silver contents and the antibacterial performances of the BC/AgNPs composites were investigated.It was found that the AgNPs impregnated on the dried BC films were inclined to achieve a faster silver releasing rate than the wet one,which was suitable for acute traumas treatment.

Green and Effective Ammonium Carbonate-assisted Process for Drying Hemicellulose Obtained through Alkali Extraction of Bleached Bamboo Kraft Pulp

Hemicellulose has a wide range of applications,including that as an emulsifier for the food industry and raw material for the synthesis of bioethanol/biochemicals and biodegradable films.Hemicellulose is usually present as a spent liquor,such as the prehydrolysis liquor of the prehydrolysis kraft dissolving pulp production process and the alkali extraction liquor of the cold caustic extraction of pulp fibers.Due to its dilute nature,hemicellulose needs to be dried for practical utilization,and this is challenging.In this study,cellulose and hemicellulose in a bleached bamboo kraft pulp were separated using an alkali extraction process.Hemicellulose obtained from the extraction liquor was dried by an ammonium carbonate-assisted drying process.The effects of drying time and drying temperature were determined.Structure of the hemicellulose obtained by the ammonium carbonate-assisted drying process was similar to that of original hemicellulose,as revealed by detailed Fourier transform infrared and X-ray diffraction analyses.The novel drying method was more energy efficient and required a shorter drying time than the conventional freeze drying method,and the excellent solubility in alkaline solutions favored the chemical modification of hemicellulose.The dried hemicellulose can be used as a renewable raw material for the preparation of hydrogels and other substances such as bioethanol/biochemicals and biodegradable films.

Comparative evaluation of processes for heavy metal removal from municipal solid waste incineration fly ash

Hydrochloric acid leaching, chloride evaporation, acetic acid leaching, and biological leaching were evaluated and compared as processes of heavy metal removal for municipal solid waste incineration fly ash(MSWFA). Six factors, namely, energy consumption, process efficiency, process handling, process cost estimation, cost reduction potential, and study progress, were used in order to find out their advantages and disadvantages and to help develop a better recovery process of heavy metals from MSWFA in terms of treatment of the waste material. Hydrochloric acid leaching process was found to be most balanced among the evaluated processes. It showed superiority on energy consumption, process cost estimation, and study progress. On the other hand, despite of its excellency in process efficiency, chloride evaporation process was most unfavorable mainly due to heavy energy dependence. Biological process, with huge potential of cost reduction, was concluded to be the second best process.

Research on physical and chemical properties and soundness of dry desulphurized fly ash used as a construction material

The physical and chemical properties and soundness of Baosteel Power Plant＇ s dry desulphurized fly ash were systematically investigated and compared with those of the similar byproducts produced by some other domestic power plants. The feasibility of these byproducts used as a construction material was also analyzed. The results show that Baosteel＇s dry desulphurized fly ash is a kind of ash with high calcium and high sulfur contents, which has the characteristics of volcanic ash activity. It contains sulfate and sulfite, and is easy to cause sulfate activation. It has higher activity compared with common fly ash. But higher calcium sulfite and free-CaO contents in ash will bring about soundness concerns to users. Therefore, quality tests and volume control will be necessary when fly ash is used as a construction material.

Preparation of Cationic Starch by Electromagnetic Dry Process (EMDP)

Introduction Cationic starches are a series of products of which various sorts with different properties and usages can all be produced via cationic reactions by using different types of etherification agents under different conditions. As an additive and strengthening agent,

Energy and Cost Analysis of Cement Production Using the Wet and Dry Processes in Nigeria

The study evaluates the energy consumption of both wet and dry processes cement manufacturing plant in Nigeria. Enrgy consumption data collected for the period 2003 to 2011 were used to estimate the energy consumption of the crushing, milling, agitation, burning, grinding and bagging operations. The total energy evaluation was based on the three primary energy sources which include electrical, combustion and human. The total estimated energy intensities were 6545 MJ/ton and 4197 MJ/ton for wet and dry processes respectively. The percentage consumption of energy in each operation is 93.68 and 90.34% (burning), 2.11 and 4.33% (milling), 0.43 and 0.67% (crushing), 1.39 and 0% (agitation), 2.12 and 3.90% (grinding), and 0.27 and 0.75% (bagging) of the total energy inputs for the wet and dry processes respectively. Furthermore, the average total energy cost of production showed that wet process is approximately 40% more cost intensive in cement production than the dry process while at the same time it is cost effective to run production on energy through gas powered plant than the national grid.

Comparative Effects of Cocoa Pod Husk and Oil Palm Bunch Ash on Nutrient Uptake, Growth and Dry Matter Yield of Cocoa (The-obroma cacao) in Ibadan, Southwest Nigeria

The high premium placed on the organically produced cocoa in the international market coupled with its health and environmental benefits necessitated recent focus on research into the use of agricultural wastes as source of nutrients in cocoa (T. cacao) production. The study was carried out at the Cocoa Research Institute of Nigeria (CRIN), Ibadan (Lat. 7&deg25'N Long. 3&deg25'E), South-western, Nigeria during the 2010/2011 seedling production season to compare the effects of NPK (20:10:10) fertilizer, Cocoa Pod Husk and Oil Palm Bunch Ash (CPHA and OPA) on the seedling growth and dry matter yield of cocoa (T. cacao). Equivalent amount of different rates of two nutrients sources CPHA and OPA were applied one month after planting at 0, 1, 2, 3, 4 and 5 t/ha respectively, recommended rate of 10 kg·N of the conventional NPK (20:10:10). Fertilizer was used as reference fertilizer. Results indicated that all the fertilizer materials positively and significantly (p > 0.05) increased the growth parameters considered. The influence of the ash materials irrespective of sources on the nutrient uptake, dry matter yield of cocoa seedlings and shoot to root ratio were either higher than or had a comparable results with the reference fertilizer (NPK 20:10:10). CPHA and OPA applied at a rate of 4 t/ha significantly (p > 0.05) increased the plant height and root length of cocoa seedlings respectively relative to control and in—organic fertilizer and could therefore be recommended for the prospective and existing Nigerian cocoa farmers for raising their seedlings in the nursery before transplanting to the field.

Optimization of Dry Ashing of Whole Blood Samples for Trace Metal Analysis

Dry ashing is an established method. Ashing whole blood samples are, however, often difficult to carry out with significant sample loss, and the procedure is not well documented. A new procedure has been devel- oped and optimized to dry-ash whole blood samples for trace metal analyses. The procedure reduces both the dry-ashing time by more than two thirds and sample loss. The ashed sample can be readily used in subse- quent, simultaneous or individual analysis of several metals by ICP-OES, as demonstrated in the analysis of a whole blood sample. The new procedure is simple, inexpensive, and faster than the established method.