scholarly journals Carbonized Steel-Smelting Slag Is a Promising Raw Material for the Production of Artificial Concrete

2022 ◽  
Author(s):  
I. Romanenko
Keyword(s):  
Carbon Dioxide ◽  
Fine Fraction ◽  
Maximum Size ◽  
Coarse Fraction ◽  
Raw Material ◽  
Steelmaking Slag ◽  
Steel Smelting ◽  
Environment Temperature ◽  
Smelting Slag ◽  
A Charge

Abstract. Obtaining an artificial stone based on steel-smelting slag is possible as a result of carbonization of the feedstock in carbon dioxide. The feedstock - slag and carbon dioxide - are by-products from steel smelting in electric furnaces, which must be disposed of in order to improve the environmental situation in the region. The condition for obtaining the cementing ability of steelmaking slag is the preparation of a charge with certain properties and maturation technology: humidity, dispersion of the fine fraction and the maximum size of the coarse fraction, the ratio between the coarse and dispersed fractions, the concentration of carbon dioxide in the gas-air environment, temperature, pressure and flow time. carbonization reactions in the reactor, the magnitude of the pressure during the production of pressed articles, the process of stone maturation in the post-carbonization period.

scholarly journals Using Steel-Smelting Slag as a Raw Material Component in the Production of Asphalt Concrete

2020 ◽  
Vol 157 ◽  
pp. 06010
Author(s):  
Dmitry Kuznetsov ◽  
Marina Vysotskaya ◽  
Albert Burgonutdinov
Keyword(s):  
Asphalt Concrete ◽  
Raw Materials ◽  
Raw Material ◽  
Crushed Stone ◽  
Fatigue Properties ◽  
Initial Moment ◽  
Type B ◽  
Steel Smelting ◽  
Smelting Slag ◽  
Mineral Powder

The possibility of using polydisperse steel-smelting slag for the production of type B asphalt concrete is investigated, the possibility of its use as a mineral powder, crushing screening and crushed stone is considered. As a result of the study, it was found that a promising area for the use of slag raw materials in the technology for the preparation of asphalt mixes is: as a mineral powder - without additional processing steps; crushing screening - with the development of additional technological operations. The use of raw materials as crushed stone is impractical because of the high average density of the final asphalt mixture. Based on the test results, the characteristics of the fatigue properties of asphalt concrete from fine-grained dense mixtures of type B made on mineral powders from slag and limestone were obtained. It was established that at the initial moment, a large number of cycles to failure are characterized by compositions on slag powder, however, samples from this series tested after 45 days showed a significant rigidity increase and were destroyed earlier than similar samples on limestone. Obviously, this phenomenon is associated with an increase in the brittle properties of the material due to the formation of crystallization-condensation bonds in the structure of asphalt concrete containing slag.

Long-term variations in individual particle types in the aerosol of Phoenix, Arizona, as determined using automated electron microprobe analysis and multivariate statistical techniques

1993 ◽  
Vol 51 ◽  
pp. 742-743
Author(s):  
Karen A. Katrinak ◽  
James R. Anderson ◽  
Peter R. Buseck
Keyword(s):  
Electron Microprobe ◽  
Fine Fraction ◽  
Coarse Fraction ◽  
Motor Vehicles ◽  
Multivariate Statistical Methods ◽  
Multivariate Statistical ◽  
X Ray ◽  
Mineral Particles ◽  
Anthropogenic Air Pollutants

Aerosol samples were collected in Phoenix, Arizona on eleven dates between July 1989 and April 1990. Elemental compositions were determined for approximately 1000 particles per sample using an electron microprobe with an energy-dispersive x-ray spectrometer. Fine-fraction samples (particle cut size of 1 to 2 μm) were analyzed for each date; coarse-fraction samples were also analyzed for four of the dates.The data were reduced using multivariate statistical methods. Cluster analysis was first used to define 35 particle types. 81% of all fine-fraction particles and 84% of the coarse-fraction particles were assigned to these types, which include mineral, metal-rich, sulfur-rich, and salt categories. "Zero-count" particles, consisting entirely of elements lighter than Na, constitute an additional category and dominate the fine fraction, reflecting the importance of anthropogenic air pollutants such as those emitted by motor vehicles. Si- and Ca-rich mineral particles dominate the coarse fraction and are also numerous in the fine fraction.

scholarly journals Recovery of Cenospheres and Fine Fraction from Coal Fly Ash by a Novel Dry Separation Method

Energies ◽  
2020 ◽  
Vol 13 (14) ◽  
pp. 3576
Author(s):  
Jan Wrona ◽  
Witold Żukowski ◽  
Dariusz Bradło ◽  
Piotr Czupryński
Keyword(s):  
Fly Ash ◽  
Coal Fly Ash ◽  
Fine Fraction ◽  
Free Fall ◽  
Raw Material ◽  
Fluidised Bed ◽  
Air Chamber ◽  
Pneumatic Separation ◽  
Bed Separation ◽  
Separation Product

Aluminosilicate microspheres are a valuable fraction of coal fly ash with diverse applications due to their low density. Currently, there is no efficient and ecologically rational method of cenosphere recovery from fly ash. A combination of dry methods for the recovery of both fine ash particles and aluminosilicate microspheres from coal fly ash is presented. It is comprised of fluidised bed separation followed by screening and pneumatic separation in a free-fall air chamber. Fluidised bed separation was assisted by a mechanical activator to prevent agglomeration. This step reduced the portion of material that required further treatment by 52–55 wt.%, with the recovery of microspheres exceeding 97%. Then, the concentrates were individually subjected to pneumatic separation. The final separation product for the fly ash containing 0.64 wt.% cenospheres was a cenosphere concentrate that constituted about 17 wt.% of the initial fly ash. The recovery of cenospheres was around 81%. Usage of a combination of dry methods allowed for maintaining almost 83 wt.% of the raw material in its dry form. Furthermore, the produced fly ash grain fractions could be used for different industrial purposes.

Low-Carbon Monoxide Hydrogen by Sorption-Enhanced Reaction

2003 ◽  
Vol 1 (1) ◽  
Author(s):  
Douglas P Harrison ◽  
Zhiyong Peng
Keyword(s):  
Carbon Dioxide ◽  
Carbon Monoxide ◽  
Hydrogen Production ◽  
Proton Exchange Membrane ◽  
Primary Energy ◽  
Proton Exchange ◽  
Raw Material ◽  
Impurity Level ◽  
Low Carbon ◽  
Enhanced Production

Hydrogen is an increasingly important chemical raw material and a probable future primary energy carrier. In many current and anticipated applications the carbon monoxide impurity level must be reduced to low-ppmv levels to avoid poisoning catalysts in downstream processes. Methanation is currently used to remove carbon monoxide in petroleum refining operations while preferential oxidation (PROX) is being developed for carbon monoxide control in fuel cells. Both approaches add an additional step to the multi-step hydrogen production process, and both inevitably result in hydrogen loss. The sorption enhanced process for hydrogen production, in which steam-methane reforming, water-gas shift, and carbon dioxide removal reactions occur simultaneously in the presence of a nickel-based reforming catalyst and a calcium-based carbon dioxide sorbent, is capable of producing high purity hydrogen containing minimal carbon monoxide in a single processing step. The process also has the potential for producing pure CO2 that is suitable for subsequent use or sequestration during the sorbent regeneration step. The current research on sorption-enhanced production of low-carbon monoxide hydrogen is an extension of previous research in this laboratory that proved the feasibility of producing 95+% hydrogen (dry basis), but without concern for the carbon monoxide concentration. This paper describes sorption-enhanced reaction conditions – temperature, feed gas composition, and volumetric feed rate – required to produce 95+% hydrogen containing low carbon monoxide concentrations suitable for direct use in, for example, a proton exchange membrane fuel cell.

Deactivation of Red Mud by Primary Aluminum Production Wastes

2021 ◽  
Vol 1040 ◽  
pp. 109-116
Author(s):  
V.Yu. Piirainen ◽  
A.A. Barinkova ◽  
V.N. Starovoytov ◽  
V.M. Barinkov
Keyword(s):  
Carbon Dioxide ◽  
Red Mud ◽  
Negative Impact ◽  
Waste Product ◽  
Primary Aluminum ◽  
Raw Material ◽  
Aluminum Production ◽  
Environmentally Safe ◽  
Primary Aluminum Production ◽  
Knowledge Intensive

Current global environmental challenges and, above all, global warming associated with a change in the carbon balance in the atmosphere has led to the need for urgent and rapid search for ways to reduce greenhouse gas emissions into the atmosphere, which primarily include carbon dioxide as a by-product of human activity and technological progress. One of these ways is the creation of industries with a complete cycle of turnover of carbon dioxide. Aluminum is the most sought-after nonferrous metal in the world, but its production is not environmentally safe, so it constantly requires the development of knowledge-intensive technologies to improve the technological process of cleaning and disposal of production waste, primarily harmful emissions into the atmosphere. Another environmental problem related to aluminum production is the formation and accumulation in mud lagoon of huge amounts of so-called highly alkaline "red mud," which is a waste product of natural bauxite raw material processing into alumina - the feedstock for aluminum production. Commonly known resources and technological methods of neutralizing red mud and working with it as ore materials for further extraction of useful components are still not used because of their low productivity and cost-effectiveness. This article describes the negative impact of waste in the form of "red" mud and carbon dioxide of primary aluminum production on the environment. The results showed that thanks to carbonization of red mud using carbon dioxide, it is possible to achieve rapid curing and its compact formation for safer transportation and storage until further use. Strength tests of concrete samples filled with deactivated red mud were also carried out, which showed the prospects of using concrete with magnesia binder.

Adjustment of a technology of cast iron smelting in the blast furnace of jsc "ural steel" w ith a volume of 1232 см3 with charge h a v in g 95% share of Mikhailovskii GOK pellets

2021 ◽  
Vol 77 (7) ◽  
pp. 768-775
Author(s):  
I. F. Iskakov ◽  
G. A. Kunitsyn ◽  
D. V. Lazarev ◽  
А. А. Red`kin ◽  
S. A. Trubitsyn ◽  
...  
Keyword(s):  
Blast Furnace ◽  
Iron Ore ◽  
Raw Materials ◽  
Raw Material ◽  
Material Base ◽  
Hot Metal ◽  
Charging System ◽  
Iron Smelting ◽  
Gas Consumption ◽  
A Charge

To use effectively internal raw material base, JSC “Ural Steel” accomplished I category major overhaul of the blast furnace No. 2. The main purpose of the overhaul was to design a rational profile which could ensure an ability to operate with a charge containing 95 % of Mikhailovskii GOK (mining and concentrating plant) pellets having basicity of 0.5 by CaO/SiO2. The blast furnace No. 2 having useful volume of 1232 m3, was constructed by design of Danieli Corus, the Netherlands, and was blown in on December 30, 2020. In the process of guarantee tests, step-by-step increase of Mikhailovskii GOK pellets (Fetotal = 60.5 %, CaO/SiO2 = 0.5) content in the charge iron ore part was being accomplished from 55 to 95.1%. Charging of the blend containing pellets in the amount of 55% of iron ore part, was done by charging system 4OOCC + 1COOCC (Ore - Coke) with filling level 1.5 m. Under conditions of pellets part increase in the blend, the charging system was changed to decrease their content at the periphery, to increase it in the ore ridge zone and make it intermediate between periphery and the ore ridge. At the pellets share in the iron ore raw materials 0.75 the charging system was used as the following: 3OOCC + 1COOC + 1COOCC, while at the content 95.1% the following charging system was used: 2COOC + 2COOC + 1COOCC. It was noted that in the period of guarantee tests the furnace running was smooth. The average silicon content in the hot metal was 0.70% at the standard deviation 0.666. Sulfur content in the hot metal did not exceed 0.024%, the blowing and natural gas consumption figures were 2100 m3/min and 11000 m3/min correspondently, oxygen content in the blowing 26.5%, hot blowing and top smoke pressure figures were 226.5 and 109.8 KPa correspondently. The productivity of the furnace was reached as high as 2358 t/day at the specific coke rate 433 kg/t of hot metal. After guarantee tests completion, the pellets content in the iron ore part was decreased gradually from 95 down to 50%. The decreasing was made by 5% in every 6 hours of operation. Application of the mastered technology of the blast furnace No. 2 with the increased share of pellets will enable to stably supply the blast furnaces No. 1, 3 and 4 by iron ore raw materials in the proportion of 30-35% of pellets and 65-70% of sinter.

scholarly journals The Hungarian Wood-Based Panel Industry and its Impact on the Environment

2016 ◽  
Vol 12 (2) ◽  
pp. 157-172
Author(s):  
Gábor Laborczy ◽  
András Winkler
Keyword(s):  
Carbon Dioxide ◽  
Power Plants ◽  
Negative Impact ◽  
Value Added ◽  
Forest Products ◽  
Air Pollutant ◽  
Raw Material ◽  
Energy Sources ◽  
Forest Products Industry ◽  
Round Wood

Abstract It is well known that worldwide deforestation has a negative impact on the global environment. Forests play an important role in producing oxygen as well as retaining gases that create the greenhouse effect. Forests primarily absorb carbon dioxide, the major air pollutant released by the industrial activities. Energy production is the major source of environmental contamination. In addition to reducing CO2 emissions, another issue this industrial sector must tackle is to decrease the use of fossil fuels by substituting them with renewable, environmentally friendly energy sources. One of the answers to these challenges is the utilization of biomass as energy sources. However, biomass-based fuels include short bolts, split round-wood, pulpwood, bark and by-products of sawmilling, which are the raw materials for the wood-based panel industry as well.Wood utilization of the forest products industry has a major impact on the delayed release of carbon dioxide stored in the wood. All over the world, just as in Hungary, the wood-based panel industry mainly uses low quality wood resources and turns them into value added products. The elongation of the life cycle of low quality wood materials decreases CO2 emissions, thus significantly contributing to environmental protection. Furthermore, it is assumed that raw material demand of the wood-based panel industry could be satisfied by focusing on sustainable forest management and well-planned reforestation. Additionally, special energy-plantations may provide extra wood resources, while waste and other non-usable parts of trees contribute to the effective and economic operation of biomass utilizing power-plants. This paper summarizes the current situation of the Hungarian wood-based panel industry and discusses the effects of the panel manufacturing processes on the environment. Also, it outlines the possible future of this important segment of the forest products industry.

scholarly journals PRODUCTION OF EXTRACTS FROM VEGETABLE RAW MATERIALS BY CARBON DIOXIDE

2020 ◽  
Vol 14 (1) ◽  
Author(s):  
K. Gafurov ◽  
B. Muhammadiev ◽  
Sh. Mirzaeva ◽  
F. Kuldosheva
Keyword(s):  
Carbon Dioxide ◽  
Supercritical Co2 ◽  
Raw Materials ◽  
Maximum Yield ◽  
Volumetric Flow Rate ◽  
Extraction Process ◽  
Raw Material ◽  
Critical Conditions ◽  
Plant Materials ◽  
Laboratory Setup

The unique properties of supercritical carbon dioxide as a solvent are widely used for extraction. In supercritical media, the dissolution of molecules of various chemical nature is possible. The purpose of this investigation was to study the extraction process and obtain extracts from valuable regional plant materials by applying CO2 extraction under pre- and supercritical conditions. The objects of research were: ground seeds of melon, pumpkin and licorice roots, as well as mint leaves, mulberry and jida flowers. For extraction, a laboratory setup was used that allows extraction when the CO2 is supplied by a high-pressure plunger pump in the sub- and supercritical state using a heat pump. The pressure range is 3-15 MPa, temperatures 295–330 K, and the volumetric flow rate above the critical CO2 is 800–900 g. Experiments with ground seeds of melon and pumpkin showed that as a result of 4 sequentially performed extraction cycles on a single load with supercritical CO2 parameters ( 315–330 K; 3–7.5 MPa) the decrease in the mass of melon seeds was 90 g (pumpkins 80 g). During the total extraction time (2.5 hours), 20 kg of CO2 were pumped through the reactor (25 l at 290 K and 6.8 MPa), while the average oil content in the extract was 4 g per 1 kg of CO2 (3.0 g per 1 l of SС-CO2) In experiments with jida flowers, the maximum amount of solid extractable substance (2% by weight of the raw material) was obtained at a temperature in the extractor of 308 K and a pressure of 7.5 MPa. Upon extraction under critical conditions in collection 2, the liquid phase was absent; only a yellow-green paste was released in it. According to the results of experiments with mint leaves, the maximum yield of a greenish liquid was observed at T = 315 K and P = 4 MPa., Mulberry - at T = 306 K and P = 6.0 MPa. The results of the extraction of oils and extracts from ground seeds of melon, pumpkin and licorice roots, as well as mint leaves, mulberries and jida flowers confirm that the maximum yield of the extracted substance is achieved with supercritical CO2 parameters in the extractor (310 K, 7.5 MPa). When liquid CO2 is extracted (300 K and 6-8 MPa), up to 2% of a yellow substance is extracted, which does not differ in appearance from a supercritical extract.

scholarly journals THE USE OF ENVIRONMENTAL WASTE IN THE ISSUE OF GREEN ECONOMY OF THE REGIONS

2021 ◽  
Author(s):  
M. Opara ◽  
Natalia Azarova
Keyword(s):  
Carbon Dioxide ◽  
Alternative Energy ◽  
Raw Materials ◽  
Human Life ◽  
Raw Material ◽  
Green Economy ◽  
Energy Sources ◽  
Alternative Energy Sources ◽  
Solid Liquid ◽  
State Of The Environment

Currently, an urgent issue is the preservation of the environment, the cyclical use of waste for the production of new products, the preservation and multiplication of the planet’s natural resources. After all, the quality of life of each person directly depends on the state of the environment and the factors that affect its preservation. These factors are an integral part of the development of a green economy. This article discusses the possibility of producing alternative energy sources, such as biofuels of three generations.The first generation is solid, liquid, and gaseous biofuels. Second-generation fuel is obtained from the biomass of plant and animal material residues, or grown crops. As an example, such a type of fuel as biogas, which consists of carbon dioxide and methane, and with its further processing, namely the separation of carbon dioxide, you can get biomethane. In the same way, such fuels as biodiesel and bioethanol can be obtained from the biological mass. And the most unusual raw material for the production of third-generation fuel is biofuel from algae. Unfortunately, the development of the green economy in Russia is taking slow steps, but at present this issue is being paid more attention. The development of technologies for obtaining alternative energy sources will allow us to produce not only new types of energy, but also to preserve the environment of our priceless planet, through the use of raw materials and waste that are not in demand in everyday human life.

scholarly journals Aerosol characterisation including oxidative potential as a proxy of health impact

2019 ◽  
Vol 29 (2) ◽  
Author(s):  
Miroslav Josipovic ◽  
Catherine Leal-Liousse ◽  
Belinda Crobeddu ◽  
Armelle Baeza-Squiban ◽  
C. Keitumetse Segakweng ◽  
...  
Keyword(s):  
Organic Carbon ◽  
Black Carbon ◽  
Fine Fraction ◽  
Health Impact ◽  
Coarse Fraction ◽  
Dry Season ◽  
Wet Season ◽  
Oxidative Potential ◽  
Ionic Content ◽  
Vaal Triangle

This study aimed to characterise aerosols sampled in the vicinity of a major industrialised area, i.e. the Vaal Triangle. It included thedetermination of oxidative potential as a predictive indicator of particle toxicity. Aerosol samples were collated through the cascadefiltering during an eight-month period (12 h over three days in one week). Three size fractions were analysed for organic carbon(OC), black carbon (BC) and oxidative potential (OP), while ionic content was presented as monthly and seasonal concentrations. Thecontinuous measurement of black carbon by an optical attenuation instrument was collated concurrently with cascade filtering. Thecarbonaceous content was low compared to the ionic one. Within the carbonaceous concentrations, the organic carbon was higherthan concentrations of black carbon in both seasons in the ultra-fine fraction; the opposite was the case for the fine fraction, whilethe coarse fraction concentrations of organic carbon in the dry season had higher concentrations than black carbon in the wet seasonand organic carbon in the wet season. The OP tended to increase as the size was decreasing for wet season aerosols, whereas, forthe dry season, the highest OP was exerted by the fine fraction. The ultrafine fraction was the one showing the most contrasting OPbetween the two seasons. Continuous monitoring indicated that the higher BC concentrations were recorded in the dry/winter partof the year, with the daily pattern of concentrations being typically bimodal, having both the morning and evening peaks in bothseasons. Within the ionic content, the dominance of sulphate, nitrate and ammonium was evident. Multiple linear correlations wereperformed between all determined compounds. Strong correlations of carboxylic acids with other organic compounds were revealed.These acids point to emissions of VOC, both anthropogenic and biogenic. Since they were equally present in both seasons, a mixtureof sources was responsible, both present in the wider area and throughout the year.

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