scholarly journals INFLUENCE OF STORAGE TIMES OF SLUDGE FROM THE FERROALLOY INDUSTRY ON THE PROPERTIES OF CEMENT-BASED MIXTURES

2021 ◽  
pp. 50-55
Author(s):  
A. M. PETROV ◽  
S. YU. SHEPTUN
Keyword(s):  
Harmful Effect ◽  
Physical And Mechanical Properties ◽  
Cement Stone ◽  
Gas Cleaning ◽  
Industrial Enterprises ◽  
Wet Gas ◽  
Cement Mortars ◽  
Duration Of Storage ◽  
Storage Times ◽  
Ferrosilicon Production

Purpose. The transition to environmentally friendly, waste-free technologies is a priority for most countries in the world. The metallurgical and construction industries make a significant contribution to the formation of large volumes of man-made waste. During the production of ferroalloys, waste is generated in the form of sludge, which is stored in sludge collectors. Sludge storage has been going on for over 25 years. In order to study the effect of the duration of storage of sludge on its properties in the compositions of dry building mixtures on a cement basis, a comparison was made of the efficiency of using sludge with different storage periods. The influence of sludge of various storage periods on the strength of dry construction is estimated. Methodology. The studies were carried out in accordance with the standard methods for determining the physical and mechanical properties of solutions from dry mixtures for the installation of self-leveling floors, specified in DSTU B V. 2.7-126: 2011 “Sludge awesome dry modified. General technical minds”. Sludge from wet gas cleaning of ferrosilicon production is stored in dumps where it is a mixture of lumps of various fractions 5…50 mm in size. To use sludge in the composition of dry building mixtures, it must be dried and crushed on a roller crusher and on a disintegrator. Findings. The best ratio of the "age" of the sludge and its percentage in the composition of the mixture was determined to increase the strength characteristics of the cement stone. Originality. The influence of the chemical nature of sludge from wet gas purifiers of ferrosilicon production on the hydration processes and strength of cement stone is analyzed. Practical value. The use of man-made waste in the formulations of dry building mixtures helps to simultaneously reduce the harmful effect on the environment of industrial enterprises and increase the mechanical and economic characteristics of cement mortars based on dry mixtures.

Hydrodynamic characteristics and efficiency of contact elements of wet-gas-cleaning equipment

1985 ◽  
Vol 49 (5) ◽  
pp. 1267-1270
Author(s):  
A. A. Andrizhievskii ◽  
A. A. Mikhalevich ◽  
A. G. Trifonov
Keyword(s):  
Hydrodynamic Characteristics ◽  
Gas Cleaning ◽  
Wet Gas ◽  
Cleaning Equipment

scholarly journals Thermal Action on Normal and High Strength Cement Mortars

2020 ◽  
Vol 10 (18) ◽  
pp. 6455
Author(s):  
Marianela Ripani ◽  
Hernán Xargay ◽  
Ignacio Iriarte ◽  
Kevin Bernardo ◽  
Antonio Caggiano ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Water Absorption ◽  
Peak Load ◽  
Physical And Mechanical Properties ◽  
Thermal Action ◽  
High Strength ◽  
Strength Loss ◽  
Brittle Behavior ◽  
Cement Mortars ◽  
Water Absorption Test

High temperature effect on cement-based composites, such as concrete or mortars, represents one of the most important damaging process that may drastically affect the mechanical and durability characteristics of structures. In this paper, the results of an experimental campaign on cement mortars submitted to high temperatures are reported and discussed. Particularly, two mixtures (i.e., Normal (MNS) and High Strength Mortar (MHS)) having different water-to-binder ratios were designed and evaluated in order to investigate the incidence of both the mortar composition and the effects of thermal treatments on their physical and mechanical properties. Mortar specimens were thermally treated in an electrical furnace, being submitted to the action of temperatures ranging from 100 to 600 °C. After that and for each mortar quality and considered temperature, including the room temperature case of 20 °C, water absorption was measured by following a capillary water absorption test. Furthermore, uniaxial compression, splitting tensile and three-points bending tests were performed under residual conditions. A comparative analysis of the progressive damage caused by temperature on physical and mechanical properties of the considered mortars types is presented. On one hand, increasing temperatures produced increasing water absorption coefficients, evidencing the effect of thermal damages which may cause an increase in the mortars accessible porosity. However, under these circumstances, the internal porosity structure of lower w/b ratio mixtures results much more thermally-damaged than those of MNS. On the other hand, strengths suffered a progressive degradation due to temperature rises. While at low to medium temperatures, strength loss resulted similar for both mortar types, at higher temperature, MNS presented a relatively greater strength loss than that of MHS. The action of temperature also caused in all cases a decrease of Young’s Modulus and an increase in the strain corresponding to peak load. However, MHS showed a much more brittle behavior in comparison with that of MNS, for all temperature cases. Finally, the obtained results demonstrated that mortar quality cannot be neglected when the action of temperature is considered, being the final material performance dependent on the physical properties which, in turn, mainly depend on the mixture proportioning.

The Waste Handling System of the Waste Disposal Department of the City of Zurich (Abfuhrwesen Zurich)

1995 ◽  
Vol 209 (3) ◽  
pp. 233-241
Author(s):  
M Lemann
Keyword(s):  
District Heating ◽  
Waste Incineration ◽  
Heating System ◽  
Cleaning Process ◽  
District Heating System ◽  
Handling System ◽  
Gas Cleaning ◽  
Wet Gas ◽  
Waste Handling ◽  
The City

This paper outlines the system used by the authorities in Zurich to treat and recycle waste in an environmentally acceptable way. The waste incineration system produces power and incorporates a district heating system as well as a wet gas-cleaning process.

Physical and mechanical characteristics of cement mortars and concretes with addition of clinoptilolite from Beli Plast deposit (Bulgaria), silica fume and fly ash

Clay Minerals ◽  
2011 ◽  
Vol 46 (2) ◽  
pp. 213-223 ◽  
Author(s):  
V. Lilkov ◽  
I. Rostovsky ◽  
O. Petrov
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Fly Ash ◽  
Silica Fume ◽  
Mechanical Characteristics ◽  
Physical And Mechanical Properties ◽  
Specific Pore Volume ◽  
Cement Mortars ◽  
Physical And Mechanical Characteristics

AbstractCement mortars and concretes incorporating clinoptilolite, silica fume and fly ash were investigated for changes in their physical and mechanical properties. It was found that additions of 10% clinoptilolite and 10% Pozzolite (1:1 mixture of silica fume and fly ash) were optimal for improvement of the quality of the hardened products, giving 8% and 13% increases in flexural and compressive strength respectively. The specific pore volume of the mortars incorporating zeolite decreased between the 28th and 180th day to levels below the values for the control composition due to the fact that clinoptilolite exhibits its pozzolanic activity later in the hydration. In these later stages, pores with radii below 500 nm increased at the expense of larger pores. The change in the pore-size distribution between the first and sixth months of hydration occurs mostly in the mortars with added zeolite.

scholarly journals The use of amorphous silica-alumina-based additive in the adhesive dry mixes of building materials

2018 ◽  
Vol 5 (1) ◽  
Author(s):  
Loganina V. I. ◽  
Zhegera Ch.V.
Keyword(s):  
Frost Resistance ◽  
Building Materials ◽  
Chemical Elements ◽  
Physical And Mechanical Properties ◽  
Adhesive Layer ◽  
Vertical Surface ◽  
Cement Stone ◽  
Plastic Strength ◽  
Silica Alumina ◽  
Amorphous Aluminosilicate

Proved the possibility of using amorphous aluminosilicate as a modifying agent for the adhesive dry mixes. Are given the data on the microstructure and chemical composition of the amorphous aluminosilicates. Installed , that the microstructure of the synthetic additives is characterized by particles of round shape, dimensions 5,208-5,704 μm, Also there are particles of elongated shape in size 7.13-8.56 μm. Predominate chemical elements O, Si, Na, S, and Al in quantity 60.69%, 31.26%, 24.23%, 18.69% and 8.29% respectively. Described the character changes in the rheological properties of cement-sand mortar, depending on the percentage of additives. Determined, that the introduction in the cement-sand mortar the additive based on amorphous aluminosilicate leads to higher values of plastic strength. Are given the model of cement stone strength using synthetic additives in the formulation. The results of the evaluation of the frost resistance of cement-based tile adhesives with the use of amorphous aluminosilicates as a modifying additive are presented. In the article is determined the mark on frost resistance of tile glue and frost resistance of the contact zone of tile glue. The evaluation of the performance properties of the layer of tile adhesive on the basis of cement, dry mixes. The calculation of the value of displacement of the adhesive layer made on the basis of the developed recipes cement dry mixes applied to a vertical surface. Experimental data obtained values of displacement tiles relative to the substrate. Described the results of physical and mechanical properties of tile adhesive made on the basis of the developed adhesive dry mix formulations.

scholarly journals THE INFLUENCE OF MICROORGANISMS ON THE PHYSICAL AND MECHANICAL PROPERTIES OF CONCRETE

2021 ◽  
Vol 6 (10) ◽  
pp. 90-98
Author(s):  
K. Strokin ◽  
D. Novikov ◽  
V. Konovalova ◽  
N. Kasiyanenko
Keyword(s):  
Bacillus Subtilis ◽  
Water Absorption ◽  
Physical And Mechanical Properties ◽  
Cement Stone ◽  
Microbiological Corrosion ◽  
Black Mold ◽  
Bacterial Corrosion ◽  
Moisture Conditions ◽  
Indoor Conditions ◽  
Physical And Mechanical Characteristics

The article considers the change in the physical and mechanical characteristics of cement stone made of the CEM I 42,5 N Portland cement in the process of bacterial and fungal corrosion for 6 months in the air and moisture conditions. It is established that the density of concrete during microbiological corrosion increases under constant moistening of the sample. However, after drying, a decrease in the density of concrete is recorded by 10 % under the influence of Bacillus subtilis bacteria and by 14 % under the influence of black mold. The degree of influence of microorganisms on the amount of water absorption of cement stone is established experimentally. Bacteria increases water absorption by 7 %, black mold increases water absorption by 10 %. Within 6 months, water absorption increased from 21 to 24,5 % for bacterial corrosion in indoor conditions, and from 24 to 29 % for fungal corrosion. When exposed to capillary moisture for 6 months, the water absorption of concrete increased to 30,4 % under the influence of Bacillus subtilis bacteria and to 37,3% under the influence of Aspergillus niger van Tieghem fungi. An increase in the water absorption of concrete is associated with an increase in porosity due to biodegradation. Under room conditions of exposure to bacteria, the porosity increases from 14,1 to 15,3 %, and from 14,3 to 17,9 % after exposure to black mold. With constant moistening, the porosity of cement concrete increases to 19,1 and 25,6 % with bacterial and fungal corrosion, respectively. The loss of compressive strength of cement stone is 13 % under the influence of bacteria and 15 % under the influence of fungi in the air for 6 months. In case of microbiological corrosion of concrete under conditions of constant wetting, the strength decreases by about 35 % in 6 months

scholarly journals Zastosowanie popiołu lotnego i szkła kineskopowego w zaprawach cementowych

2018 ◽  
Vol 27 (3) ◽  
pp. 348-354 ◽  
Author(s):  
Jakub Jura ◽  
Małgorzata Ulewicz
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Cement Mortar ◽  
Physical And Mechanical Properties ◽  
Waste Materials ◽  
Glass Cullet ◽  
Glass Waste ◽  
Cement Mortars ◽  
Resistance Tests ◽  
Made In

The article presents the results of research aimed at using glass waste and ash from biomass. The tests were carried out for cement mortars samples with using glass cullet, ash from biomass and using both wastes in 50/50 proportions. The physical and mechanical properties of the standard mortar and modified mortars were tested. Standard mortar and cement mortar samples were made in which 10, 20 and 30% of the cement mass was used as part of the standard sand. The samples were made of CEM I 42.5R. Mortars containing fly ash addition had an increased compressive strength and a smaller drop in compressive strength after frost resistance tests than standard mortar. The use of glass cullet in the amount of up to 20% did not reveal any changes in the mechanical properties of mortars, but using them in a larger amount resulted in unfavorable results. The use of a mixture of these two waste materials did not improve the results. The research has shown the possibility of using this waste to modify cement mortars.

scholarly journals Improving the Efficiency of the Wet Gas Cleaning Process in a Venturi Tube by Superposition of Ultrasonic Fields

2019 ◽  
Vol 25 (4) ◽  
pp. 580-588
Author(s):  
V. N. Khmelev ◽  
◽  
A. V. Shalunov ◽  
V. A. Nesterov ◽  
A. C. Bochenkov ◽  
...  
Keyword(s):  
Venturi Tube ◽  
Cleaning Process ◽  
Gas Cleaning ◽  
Ultrasonic Fields ◽  
Wet Gas

scholarly journals Review of studies on plugging compositions creation with controlled rheological properties and the ability to restore fluidity for completion, workover and abandonment of oil and gas wells

2021 ◽  
pp. 28-46
Author(s):  
D. S. Klimov ◽  
◽  
S. S. Ostapchuk ◽  
E. S. Zakirov ◽  
◽  
...  
Keyword(s):  
Oil And Gas ◽  
Experimental Studies ◽  
Physical And Mechanical Properties ◽  
Dynamic Loads ◽  
Cement Stone ◽  
Self Healing ◽  
Gas Wells ◽  
Oil And Gas Wells ◽  
Influence Of Temperature On ◽  
Zonal Isolation

The main purpose of cementing oil and gas wells is zonal isolation of the formations exposed by the wellbore. During the entire life of the well, there should be no uncontrolled hydraulic communication between the developed formations and the surface, regardless of the composition and type of fluid (water, oil or gas). During the operation of the well, in addition to constant static ones, the casing and cement stone also experience various dynamic loads. The article presents an up-to-date review of experimental studies on the modification of grouting compositions and cement composites capable of autonomous selfhealing due to the introduction of various additives and nanomaterials. Such modification technologies significantly increase the tightness and resistance of cement to the effects of dynamic loads, the integrity of the cement stone. As a replacement for traditional cement materials, the authors propose the creation of grouting compositions with controlled physical and mechanical properties and the possibility of their re-liquefaction under the influence of temperature on the basis of bitumen or bitumen composites. Keywords: well plugging and abandoning; self-healing materials; autonomous self-healing; casing durability; impermeability of the cement stone; self-healing cement; bitumen and bitumen composites.

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