Immobilization of Powdered Coal Fly Ashes (CFAs) into CFA Beads and Column Studies on Color Removal from Pulp Mill Effluents Using These CFA Beads

In this study, immobilization process of the three (3) powder CFAs was studied. The major results on immobilization process were briefly presented. A total number of fifteen (15) column studies from the combination of the five (5) types of CFAs beads and the three (3) PMEs samples were performed. In each column study, a set of aggregate parameters of flow rate, empty bed contract time, operational time, and throughput volume was studied, and the data was fitted to existing modeling of breakthrough curves. The overall operational time was 12–24-hour, color removal efficiencies were 40–90%, and throughput volume of treated PMEs was 10–14 bed volume. For the column study, the correlation coefficient R2 value for each combination indicated that the Thomas model had a better fit with the observed data than the Adams-Bohart model, and the color adsorption capacities of CFA beads varied in a wide range of 0.31–28.23 mg/g.

Еfficiency increase of powdered coal application at hot metal production and limestone calcination under unstable technology conditions

Operation of Ukraine ferrous metallurgy under conditions of dependence on import and instability of energy carriers supply, shortage of investments in modernization of production equipment, make the matter of cooperation between steel-works and research organization particularly actual. Basic results of cooperation between Z.I. Nekrasov Institute of Ferrous metallurgy, NAN of Ukraine and Dnepr steel-works in 2017–2019 on blast sfurnace operation pefection and technology of powdered coal injection into rotating limestone calcination furnaces. Results of the finding of the powdered coal optimal consumption shown, which ensure a high efficiency of the coke substitution, reaching of maximum possible blast furnace productivity as well as satisfactory utilization degree of the reducing gas ability. Results of implementation of a complex of measures presented, which ensure a rational distribution of the powdered coal by BF air tuyeres for making the heat conditions of the tuyere zone even by the blast furnace circle. Efficiency of application of technology of joint injection the powdered coal and natural gas was shown, which is achieved by improving the powdered coal combustion conditions in case of increase their mixing degree. Recommendations quoted for blast furnaces starting-up after their idling for a period exceeding the permissible one, without tapping the plug hot metal. The recommendations ensure an accident-free putting a blast furnace into operation followed by reaching planned parameters. Results of usage sensors information, measuring temperature of gas flow above the charge surface presented. The results allow to prove the correction of blast furnace charging mode by an expert module, generating correction impact to support control actions by technological personal. A complex of measures formed to prevent a disturbance of a blast furnace running in case of powdered coal injection in an amount exceeding 140 kg/t of hot metal and without application of special washover materials. The results of efficiency of the mastered technology, envisaging application manganese-bearing materials at a constant base, were shown. Results of diagnostics of workability of the facility for powdered coal injection into rotating limestone calcinating furnace presented, followed by elaboration recommendation on correction parameters of injection facility operation.

Ecologically closed energymetallurgical technology of powdered iron ore and coal-cleaning wastes processing

The problem of coal-cleaning wastes utilization is actual in many countries of the world. At present in Russia these wastes are used only at 10–15% in different industries, but the potential of their utilization is much wider. Peculiarities of waste-less technology of powdered coal-cleaning wastes gasification in the slag suspended layer considered, resulted in conditional synthesis gas obtaining with simultaneous reducing and isolation of metal from ash and slag. Besides, another result was obtaining a highporous alumina-silicate slag (microspheres), applicable as a light filler for paints and coatings with low heat conductivity, as well as absorbing agent etc. It was shown, that based on the earlier elaborated jet-emulsion facility, a waste-less technology of gasification (processing) of coal and its cleaning wastes can be created resulting in obtaining three liquid products: synthesis gas (or electric power), alumina-silicate micro granules and iron with dissolved in it rare metals. Apart from the wastes of coal-cleaning availability, the presence of powdered iron-containing wastes (dust from gas-cleaning systems, iron ore concentration tails) can increase the efficiency of the technology. The increase will take place due to stable gas-slag emulsion support and the two-phase flow in the connection channels, as well as decrease of gaseous oxygen consumption at the expense of it substitution by oxygen of iron oxides.

The Feasibility Study on GRP Waste Used as Alternative Fuel for Cement Production

Polymer resin and glass fiber are the main wastes during the production process of glass-fiber reinforced plastics (GRP). With GRP products used widely in many fields, GRP wastes also got a large increase and the disposal of GRP wastes became a serious environmental problem. In this paper, the combustion characteristic of GRP wastes was tested by the thermal analysis and contrasted to that of powdered coal. In the full-scale test of GRP wastes co-processing in the cement kiln, the efficiency of coal-saving, the influence on chemical components of the product and the CO2 emission were investigated to evaluate the feasibility of this technology.

Study on Fly Ash for Conditioning of Specific Resistance of Sludge Water

Effect of the dosage of flocculants on sludge dewatering is analyzed through the determination of sludge specific resistance to filtration. Sludge dewatering behaviors conditioned on Polymeric aluminum, PAM, fly ash and composite flocculants have been compared. The results show all the conditioning agent have help to sludge dewatering. Fly ash from electric power plant as conditioning agent can greatly reduce the specific resistance of sludge and the dewatering performance can be improved.The optimal dosage of fine powdered coal is 20g/100mL and coarse powdered coal is 30g/100mL.Powdered coal is mixed with sludge to form filter cake which is blended with coal in certain proportion to make into fuel.

Zeolites P1 Formation by Hydrothermal Alkali Fusion of Coal Fly Ash

Fly ash is produced from the combustion of powdered coal and used to synthesize zeolite by alkali fusion followed by hydrothermal treatment with stirring. By varying the experimental conditions different types of zeolite were produced. In this study, mixture of sodium hydroxide and fly ash in a pre-determined ratio, was milled and fused at 700°C for 1h.The resultant fused mixture added to water in a Teflon reaction vessel and incubated at a temperature of 100°C and autogenously pressure. At the end, the reaction products recovered by filtration. The synthesized zeolite was characterized using various techniques such as X-ray diffraction, scanning electron microscopy. The zeolite-P1 was tested for decontamination potential of mine water. High removal efficiency was observed in the first treatment, but varied for different contaminants. The synthesised zeolite-P1 exhibited a high efficiency for the removal of heavy metal cations, such as zinc, copper, lead and cadmium from contaminated mine water.

The Study on Low Power Consumption Technology of the Walls Based on Powdered Caol Ash and Karst Slab Building Material — Take for Example Karst Region in Guizhou, China

Guizhou is situated in the biggest continuous karst strap. Carbonate rock cropping-out reaches 130,000 square kilometers. It is also a province quite rich in coal resources. There have been constructed 12 thermal power plants fueled with coal. As the inevitable outcome, the discharge of coal ashes each year reaches over 1,580,000 tons. Based on this special material produced by the natural environment, this study designs a kind of powdered-coal-ash building block walls, which not only preserve heat and insulate heat, but also embody the regional features, thus making the powdered coal ash and karst rock become the real green material. With the respect to the designing method, we produce, in accordance with the (JGJ134-2001) standard , a kind of sandwich building blocks, which can retain heat and insulate heat. Then on the block outside, we hang stone slabs to make the slab and the block form a certain width ventilation space, thus a sandwiching wall of powdered coal ash and slab is constructed. By making use of heat pressure principle, heat is discharged. Through theoretical analysis, and simulations, etc., it shows that karst rock material and the powdered coal ash are green materials, which play a necessary part of regional features, heat preservation and heat insulation.